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ORGANIC SPECTROSCOPY

Read all about Organic Spectroscopy on ORGANIC SPECTROSCOPY INTERNATIONAL 

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DR ANTHONY MELVIN CRASTO Ph.D

DR ANTHONY MELVIN CRASTO Ph.D

DR ANTHONY MELVIN CRASTO, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his Ph.D from ICT, 1991,Matunga, Mumbai, India, in Organic Chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with GLENMARK PHARMACEUTICALS LTD, Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 30 plus yrs, Prior to joining Glenmark, he has worked with major multinationals like Hoechst Marion Roussel, now Sanofi, Searle India Ltd, now RPG lifesciences, etc. He has worked with notable scientists like Dr K Nagarajan, Dr Ralph Stapel, Prof S Seshadri, Dr T.V. Radhakrishnan and Dr B. K. Kulkarni, etc, He did custom synthesis for major multinationals in his career like BASF, Novartis, Sanofi, etc., He has worked in Discovery, Natural products, Bulk drugs, Generics, Intermediates, Fine chemicals, Neutraceuticals, GMP, Scaleups, etc, he is now helping millions, has 9 million plus hits on Google on all Organic chemistry websites. His friends call him Open superstar worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international, etc in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 30 year tenure till date Dec 2017, Around 35 plus products in his career. He has good knowledge of IPM, GMP, Regulatory aspects, he has several International patents published worldwide . He has good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, Polymorphism etc., He suffered a paralytic stroke/ Acute Transverse mylitis in Dec 2007 and is 90 %Paralysed, He is bound to a wheelchair, this seems to have injected feul in him to help chemists all around the world, he is more active than before and is pushing boundaries, He has 9 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 50 Lakh plus views on dozen plus blogs, He makes himself available to all, contact him on +91 9323115463, email amcrasto@gmail.com, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 19 lakh plus views on New Drug Approvals Blog in 216 countries......https://newdrugapprovals.wordpress.com/ , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc

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WCK 5222, Wockhardt receives QIDP status for its new drug WCK 5222 from USFDA


 

WCK 5222

Watch this post as I get to the structure…………..

DEC2015

Wockhardt has received Qualified Infectious Disease Product (QIDP) status for its new drug WCK 5222,  a product from its breakthrough New Drug Discovery program in Anti Infectives from the US Food and Drug Administration (FDA).
This is the fourth product from the company to receive this coveted status. During last year, the company has received approval for WCK 771 & WCK 2349 and in early this year approval was received for WCK 4873. The only company globally to receive QIDP status for 4 drugs from US FDA.
Wockhardt is one of the few companies with end to end integrated capabilities for its products, starting with the manufacture of the oral and sterile API’s, the dose forms and marketing through wholly owned subsidiary in the US, enabling the company to capture maximum value.

 

Ten compounds generally represented by a general Formula (I) were used and are as follows:

(a) Sodium salt of ir ns-7-oxo-6-sulphooxy-l ,6-diazabicyclo[3.2.1]-octane-2-carbonitrile (Compound A);

(b) trans-sulphuric acid mono-[2-(5-carboxamido)-[l ,3,4]-oxadiazol-2-yl)-7-oxo-l,6-diazabicyclo[3.2.1]-octan-6-yl] ester (Compound B);

(c) trans-sulphuric acid mono-[2-(5-(piperidin-4-yl)-[l ,3,4]-oxadiazol-2-yl)-7-oxo-l,6-diazabicyclo[3.2.1]-octan-6-yl] ester (Compound C);

(d) trans-sulphuric acid mono-[2-(5-azetidin-3-ylmethyl-[l ,3,4]-oxadiazol-2-yl)-7-oxo-l,6-diazabicyclo[3.2.1]-octan-6-yl] ester (Compound D);

(e) (25,5i?)-7-Oxo-6-sulphooxy-2-[N’-((i?)-piperidine-3-carbonyl)-hydrazinocarbonyl] -1,6-diaza-bicyclo[3.2.1]octane (Compound E);

(f) (25, 5i?)-7-Oxo-N-[(25)-pyrrolidin-2-ylmethoxy]-6-(sulfooxy)-l,6-diaza bicyclo [3.2.1] octane-2-carboxamide (Compound F);

(g) (25,5i?)-7-Oxo-6-sulphooxy-2-[N’-((i?)-pyrrolidine-3-carbonyl)-hydrazinocarbonyl]-l ,6-diaza -bicyclo[3.2.1]octane (Compound G);

(h) (25,5i?)-7-Oxo-N-[(25)-piperidine-2-ylmethyloxy]-6-(sulfooxy)-l ,6-diazabicyclo

octane-2-carboxamide (Compound H);

(i) trans-sulphuric acid mono-[2-(5-((5)-l-amino-ethyl)-[l ,3,4]-oxadiazol-2-yl)-7-oxo-l,6-diazabicyclo[3.2.1]-octan-6-yl] ester (Compound I); and

j) trans-sulphuric acid mono-[2-(5-((5)-pyrrolidin-2-yl)-[l,3,4]-oxadiazol-2-yl)-7-oxo-l,6-diazabicyclo[3.2.1]-octan-6-yl] ester (Compound J).

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FDA grants breakthrough status for Pfizer’s leukaemia drug inotuzumab ozogamicin


 

Inotuzumab ozogamicin
RN: 635715-01-4
UNII: P93RUU11P7

Pfizer Inc., Oncology Institute Of Southern Switzerland  INNOVATOR

2D chemical structure of 635715-01-4

http://chem.sis.nlm.nih.gov/chemidplus/rn/635715-01-4

  • MF 1680.6764
  • Oncological Treatment

FDA grants breakthrough status for Pfizer’s leukaemia drug inotuzumab ozogamicin
The US Food and Drug Administration (FDA) has granted breakthrough therapy designation for Pfizer’s investigational antibody-drug conjugate (ADC) inotuzumab ozogamicin to treat acute lymphoblastic leukaemia (ALL).

The US Food and Drug Administration (FDA) has granted breakthrough therapy designation for Pfizer’s investigational antibody-drug conjugate (ADC) inotuzumab ozogamicin to treat acute lymphoblastic leukaemia (ALL).

The breakthrough status was based on data from the Phase III INO-VATE ALL trial, which enrolled 326 adult patients with relapsed or refractory CD22-positive ALL and compared inotuzumab ozogamicin to standard of care chemotherapy………….http://www.pharmaceutical-technology.com/news/newsfda-grants-breakthrough-status-pfizer-leukaemia-drug-inotuzumab-ozogamicin-4697877?WT.mc_id=DN_News

EVER SINCE POST WAS WRITTEN…..FGD APPROVAL Inotuzumab ozogamicin

PFIZER

Image result for inotuzumab ozogamicin

Image result for inotuzumab ozogamicinImage result for inotuzumab ozogamicin

Besponsa FDA

8/17/2017

To treat adults with relapsed or refractory acute lymphoblastic leukemia
Press Release
Drug Trials Snapshot

LINK….https://newdrugapprovals.org/2015/10/23/fda-grants-breakthrough-status-for-pfizers-leukaemia-drug-inotuzumab-ozogamicin/

 

Inotuzumab ozogamicin (CMC-544) is an antibody-drug conjugate for the treatment of cancers.[1] It consists of the humanized monoclonal antibody inotuzumab (for CD22), linked to a cytotoxic agent from the class of calicheamicins (which is reflected by ‘ozogamicin‘ in the drug’s name).[2]

This drug is being developed by Pfizer and UCB.

It is undergoing numerous clinical trials,[3] including two phase II trials for Non-Hodgkin lymphoma (NHL).

A phase III trial in patients with follicular b-cell NHL has been terminated due to poor enrollment.[4] A Phase III trial in patients with relapsed or refractory CD22+ aggressive non-Hodgkin lymphoma (NHL) who were not candidates for intensive high-dose chemotherapy was terminated for futility.[5]

Monoclonal antibodies (mAbs) and derivatives are currently the fastest growing class of therapeutic molecules. More than 30 G-type immunoglobulins (IgG) and related agents have been approved over the past 25 years mainly for cancers and inflammatory diseases. In oncology, mAbs are often combined with cytotoxic drugs to enhance their therapeutic efficacy. Alternatively, small anti-neoplastic molecules can be chemically conjugated to mAbs, used both as carriers (increased half-life) and as targeting agents (selectivity). Potential benefits of antibody-drug conjugates (ADCs), strategies, and development challenges are discussed in this review. Several examples of ADCs are presented with emphasis on three major molecules currently in late clinical development as well as next generation thio-mAbs conjugates with improved therapeutic index.

PATENT

http://www.google.com/patents/WO2013088304A1?cl=en

Inotuzumab ozogamicin:

Figure imgf000012_0001

is described in U.S. Patent Application No. 10/428894

 

 

U.S. Patent Application No. 10/428894

 

 

 

 

References

  1.  Statement On A Nonproprietary Name Adopted By The Usan Council – Inotuzumab ozogamicin, American Medical Association.
  2.  Takeshita, A; Shinjo, K; Yamakage, N; Ono, T; Hirano, I; Matsui, H; Shigeno, K; Nakamura, S; Tobita, T; Maekawa, M (2009). “CMC-544 (inotuzumab ozogamicin) shows less effect on multidrug resistant cells: analyses in cell lines and cells from patients with B-cell chronic lymphocytic leukaemia and lymphoma.”. British journal of haematology 146 (1): 34–43.doi:10.1111/j.1365-2141.2009.07701.x. PMID 19388933.
  3.  http://clinicaltrials.gov/ct2/results?term=Inotuzumab+ozogamicin
  4.  http://clinicaltrials.gov/ct2/show/NCT00562965
  5.  http://pfizer.newshq.businesswire.com/press-release/pfizer-discontinues-phase-3-study-inotuzumab-ozogamicin-relapsed-or-refractory-aggress
  6. http://pubs.rsc.org/en/content/articlelanding/2008/np/b514294f#!divAbstract

Structure of inotuzumab ozogamicin. ABOVE

Inotuzumab ozogamicin?
Monoclonal antibody
Type Whole antibody
Source Humanized (from mouse)
Target CD22
Identifiers
CAS Registry Number 635715-01-4 
ATC code None
UNII P93RUU11P7 
KEGG D08933 Yes
Chemical data
Formula C6518H10002N1738O2036S42
Molecular mass 150,000 Daltons

//////////

Necessity of Establishing Chemical Integrity of Polymorphs of Drug Substance Using a Combination of NMR, HPLC, Elemental Analysis, and Solid-State Characterization Techniques: Case Studies


Abstract Image

Necessity of Establishing Chemical Integrity of Polymorphs of Drug Substance Using a Combination of NMR, HPLC, Elemental Analysis, and Solid-State Characterization Techniques: Case Studies

Chemical Process Research Laboratory, USV Limited, Arvind Vithal Gandhi Chowk, BSD Marg, Govandi, Mumbai – 400 088, India
Org. Process Res. Dev., 2013, 17 (3), pp 519–532
DOI: 10.1021/op300229k
Polymorphism is a solid-state phenomenon; hence, solid-state techniques such as XRPD, DSC, and FT-IR are used for characterization. Many a time, only XRPD is used. These techniques ignore the most important aspects, i.e., chemical purity and the chemical integrity of the polymorph, which can be confirmed by techniques such as 1H NMR, HPLC, and elemental analysis. The aim of this article is to emphasize how techniques such as 1H NMR, elemental analysis, and HPLC purity in addition to other solid-state characterization techniques would help to prove that the drug really exists in different polymorphic forms. H1NMR, HPLC, and elemental analysis reveal the formation of different compounds and not polymorphs in the case of pioglitazone·HCl and glyburide. In the cases of irbesartan and ropinirole·HCl use of a single solid-state characterization technique such as XRPD is not enough for establishing the existence of different polymorphic forms.

US priority review for Eisai cancer drug lenvatinib


US priority review for Eisai cancer drug lenvatinib

Eisai has been boosted by news that regulators in the USA have agreed to a quicker review of its anticancer agent lenvatinib.

The US Food and Drug Administration has granted a priority review to Eisai’s New Drug Application for lenvatinib as a treatment for progressive radioiodine-refractory differentiated thyroid cancer. This means that the agency has assigned a Prescription Drug User Fee Act action date of April 14 next year, eight months after the NDA was submitted.

Read more at: http://www.pharmatimes.com/Article/14-10-15/US_priority_review_for_Eisai_cancer_drug_lenvatinib.aspx#ixzz3GH3iXiDU 

SEE SYNTHESIS

https://newdrugapprovals.org/2014/08/04/eisais-lenvatinib-%E5%85%B0%E4%BC%90%E6%9B%BF%E5%B0%BC-%E3%83%AC%E3%83%B3%E3%83%90%E3%83%81%E3%83%8B%E3%83%96-to-get-speedy-review-in-europe/

 

 

 

 

 

BI launches COPD drug Striverdi, olodaterol in UK and Ireland


DB09080.png

Olodaterol

BI-1744
BI-1744-CL (hydrochloride) marketed as drug

Boehringer Ingelheim Pharma  innovator

synthesis…..http://wendang.baidu.com/view/d4f95541e518964bcf847c22.html

Olodaterol (trade name Striverdi) is a long acting beta-adrenoceptor agonist used as an inhalation for treating patients with chronic obstructive pulmonary disease (COPD), manufactured by Boehringer-Ingelheim.[1]

see……….https://www.thieme-connect.de/DOI/DOI?10.1055/s-0029-1219649           ……… synfacts

Olodaterol is a potent agonist of the human β2-adrenoceptor with a high β12 selectivity. Its crystalline hydrochloride salt is suitable for inhalation and is currently undergoing clinical trials in man for the treatment of asthma. Oloda­terol has a duration of action that exceeds 24 hours in two preclinical animal models of bronchoprotection and it has a better safety margin compared with formoterol.

Olodaterol hydrochloride [USAN]

Bi 1744 cl
Bi-1744-cl
Olodaterol hydrochloride
Olodaterol hydrochloride [usan]
UNII-65R445W3V9

868049-49-4 [RN] FREE FORM

CAS 869477-96-3 HCL SALT

R ENANTIOMER

2H-1,4-Benzoxazin-3(4H)-one, 6-hydroxy-8-((1R)-1-hydroxy-2-((2-(4-methoxyphenyl)- 1,1-dimethylethyl)amino)ethyl)-, hydrochloride (1:1)

2H-1,4-benzoxazin-3(4H)-one, 6-hydroxy-8-((1R)-1-hydroxy-2-((2-(4-methoxyphenyl)- 1,1-dimethylethyl)amino)ethyl)-, hydrochloride (1:1)

6-Hydroxy-8-((1R)-1-hydroxy-2-((2-(4-methoxyphenyl)-1,1-dimethylethyl)amino)ethyl)- 2H-1,4-benzoxazin-3(4H)-one hydrochloride

clinical trialshttp://clinicaltrials.gov/search/intervention=Olodaterol+OR+BI+1744

Boehringer Ingelheim has launched a new chronic obstructive pulmonary disease drug, Striverdi in the UK and Ireland.
Striverdi (olodaterol) is the second molecule to be licenced for delivery via the company’s Respimat Soft Mist inhaler, following the COPD blockbuster Spiriva (tiotropium). The drug was approved in Europe in November based on results from a Phase III programme that included more than 3,000 patients with moderate to very severe disease.http://www.pharmatimes.com/Article/14-07-01/BI_launches_COPD_drug_Striverdi_in_UK_and_Ireland.aspx

Olodaterol hydrochloride is a drug candidate originated by Boehringer Ingelheim. The product, delivered once-daily by the Respimat Soft Mist Inhaler, was first launched in Denmark and the Netherlands in March 2014 for the use as maintenance treatment of chronic obstructive pulmonary disease (COPD), including chronic bronchitis and/or emphysema. In 2013, approval was obtained in Russia and Canada for the same indication, and in the U.S, the product was recommended for approval. Phase III clinical trials for the treatment of COPD are ongoing in Japan.

ChemSpider 2D Image | Olodaterol | C21H26N2O5
Systematic (IUPAC) name
6-hydroxy-8-{(1R)-1-hydroxy-2-{[1-(4-methoxyphenyl)-2-methylpropan-2-yl]amino}ethyl}-4H-1,4-benzoxazin-3-one
Clinical data
Trade names Striverdi
AHFS/Drugs.com UK Drug Information
Pregnancy cat. No experience
Legal status POM (UK)
Routes Inhalation
Identifiers
CAS number 868049-49-4; 869477-96-3 (hydrochloride)
ATC code R03AC19
PubChem CID 11504295
ChemSpider 9679097
UNII VD2YSN1AFD
ChEMBL CHEMBL605846
Synonyms BI 1744 CL
Chemical data
Formula C21H26N2O5 free form
C21 H26 N2 O5 . Cl H; of hcl salt
Mol. mass 386.44 g/mol free form; 422.902 as hyd salt

BI launches COPD drug Striverdi in UK and Ireland

Medical uses

Olodaterol is a once-daily maintenance bronchodilator treatment of airflow obstruction in patients with COPD including chronic bronchitis and/or emphysema, and is administered in an inhaler called Respimat Soft Mist Inhaler.[2][3][4][5][6][7]

As of December 2013, olodaterol is not approved for the treatment of asthma. Olodaterol monotherapy was previously evaluated in four Phase 2 studies in asthma patients. However, currently there are no Phase 3 studies planned for olodaterol monotherapy in patients with asthma.

In late January 2013, Olodaterol CAS# 868049-49-4 was the focus of an FDA committee reviewing data for the drug’s approval as a once-daily maintenance bronchodilator to treat chronic obstructive pulmonary disease (COPD), as well as chronic bronchitis and emphysema. The FDA Pulmonary-Allergy Drugs Advisory Committee recommended that the clinical data from the Boehringer Ingelheim Phase III studies be included in their NDA.

Also known as the trade name Striverdi Respimat, Olodaterol is efficacious as a long-acting beta-agonist, which patients self-administer via an easy to use metered dose inhaler. While early statistics from clinical trials of Olodaterol were encouraging, a new set of data was released earlier this week, which only further solidified the effectual and tolerable benefits of this COPD drug.

On September 10, 2013 results from two Phase 3 studies of Olodaterol revealed additional positive results from this formidable COPD treatment. The conclusion from these two 48 week studies, which included over 3,000 patients, showed sizable and significant improvements in the lung function of patients who were dosed with Olodaterol. Patients in the aforementioned studies were administered either a once a day dosage of Olodaterol via the appropriate metered-dose inhaler or “usual care”. The “usual care” included a variety of treatment options, such as inhaled corticosteroids (not Olodaterol), short and long acting anticholinergics, xanthines and beta agonists, which were short acting. The clinical trial participants who were dosed with Olodaterol displayed a rapid onset of action from this drug, oftentimes within the first five minutes after taking this medication. Additionally, patients dispensed the Olodaterol inhaler were successfully able to maintain optimum lung function for longer than a full 24 hour period. The participants who were given Olodaterol experienced such an obvious clinical improvement in their COPD symptoms, and it quickly became apparent that the “usual care” protocol was lacking in efficacy and reliability.

A staggering 24 million patients in the United States suffer from chronic obstructive pulmonary disease, and this patient population is in need of an effectual, safe and tolerable solution. Olodaterol is shaping up to be that much needed solution. Not only have the results from studies of Olodaterol been encouraging, the studies themselves have actually been forward thinking and wellness centered. Boehringer Ingelheim is the first company to included studies to evaluate exercise tolerance in  patients with COPD, and compare the data to those patients who were dosed with Olodaterol. By including exercise tolerance as an important benchmark in pertinent data for Olodaterol, Boehringer Ingelheim has created a standard for COPD treatment expectations. The impaired lung function for patients with COPD contributes greatly to their inability to exercise and stay healthy. Patients who find treatments and management techniques to combat the lung hyperinflation that develops during exercise have a distinct advantage to attaining overall good health.

– See more at: http://www.lgmpharma.com/blog/olodaterol-offers-encouraging-results-patients-copd/#sthash.DOjcrGxc.dpuf

Data has demonstrated that Striverdi, a once-daily long-acting beta2 agonist, significantly improved lung function versus placebo and is comparable to improvements shown with the older LABA formoterol. The NHS price for the drug is £26.35 for a 30-day supply.

Boehringer cited Richard Russell at Wexham Park Hospital as saying that the licensing of Stirverdi will be welcomed by clinicians as it provides another option. He added that the trial results showing improvements in lung function “are particularly impressive considering the study design, which allowed participants to continue their usual treatment regimen. This reflects more closely the real-world patient population”.

Significantly, the company is also developing olodaterol in combination with Spiriva, a long-acting muscarinic antagonist. LAMA/LABA combinations provide the convenience of delivering the two major bronchodilator classes.

Olodaterol is a novel, long-acting beta2-adrenergic agonist (LABA) that exerts its pharmacological effect by binding and activating beta2-adrenergic receptors located primarily in the lungs. Beta2-adrenergic receptors are membrane-bound receptors that are normally activated by endogenous epinephrine whose signalling, via a downstream L-type calcium channel interaction, mediates smooth muscle relaxation and bronchodilation. Activation of the receptor stimulates an associated G protein which then activates adenylate cyclase, catalyzing the formation of cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA). Elevation of these two molecules induces bronchodilation by relaxation of airway smooth muscles. It is by this mechanism that olodaterol is used for the treatment of chronic obstructive pulmonary disease (COPD) and the progressive airflow obstruction that is characteristic of it. Treatment with bronchodilators helps to mitigate associated symptoms such as shortness of breath, cough, and sputum production. Single doses of olodaterol have been shown to improve forced expiratory volume in 1 sec (FEV1) for 24 h in patients with COPD, allowing once daily dosing. A once-a-day treatment with a LABA has several advantages over short-acting bronchodilators and twice-daily LABAs including improved convenience and compliance and improved airflow over a 24-hour period. Despite similarities in symptoms, olodaterol is not indicated for the treatment of acute exacerbations of COPD or for the treatment of asthma.

Adverse effects

Adverse effects generally were rare and mild in clinical studies. Most common, but still affecting no more than 1% of patients, were nasopharyngitis (running nose), dizziness and rash. To judge from the drug’s mechanism of action and from experiences with related drugs, hypertension (high blood pressure), tachycardia (fast heartbeat), hypokalaemia (low blood levels of potassium), shaking, etc., might occur in some patients, but these effects have rarely, if at all, been observed in studies.[1]

Interactions

Based on theoretical considerations, co-application of other beta-adrenoceptor agonists, potassium lowering drugs (e. g. corticoids, many diuretics, and theophylline), tricyclic antidepressants, and monoamine oxidase inhibitors could increase the likelihood of adverse effects to occur. Beta blockers, a group of drugs for the treatment of hypertension (high blood pressure) and various conditions of the heart, could reduce the efficacy of olodaterol.[1] Clinical data on the relevance of such interactions are very limited.

Pharmacology

Mechanism of action

Like all beta-adrenoceptor agonists, olodaterol mimics the effect of epinephrine at beta-2 receptors (β₂-receptors) in the lung, which causes the bronchi to relax and reduces their resistance to airflow.[3]

Olodaterol is a nearly full β₂-agonist, having 88% intrinsic activity compared to the gold standard isoprenaline. Its half maximal effective concentration (EC50) is 0.1 nM. It has a higher in vitro selectivity for β₂-receptors than the related drugs formoterol and salmeterol: 241-fold versus β₁- and 2299-fold versus β₃-receptors.[2] The high β₂/β₁ selectivity may account for the apparent lack of tachycardia in clinical trials, which is mediated by β₁-receptors on the heart.

Pharmacokinetics

Once bound to a β₂-receptor, an olodaterol molecule stays there for hours – its dissociation half-life is 17.8 hours –, which allows for once-a-day application of the drug[3] like with indacaterol. Other related compounds generally have a shorter duration of action and have to be applied twice daily (e.g. formoterol, salmeterol). Still others (e. g. salbutamol, fenoterol) have to be applied three or four times a day for continuous action, which can also be an advantage for patients who need to apply β₂-agonists only occasionally, for example in an asthma attack.[8]

 

History

On 29 January 2013 the U.S. Food and Drug Administration (FDA) Pulmonary-Allergy Drugs Advisory Committee (PADAC) recommended that the clinical data included in the new drug application (NDA) for olodaterol provide substantial evidence of safety and efficacy to support the approval of olodaterol as a once-daily maintenance bronchodilator treatment for airflow obstruction in patients with COPD.[9]

On 18 October 2013 approval of olodaterol in the first three European countries – the United Kingdom, Denmark and Iceland – was announced by the manufacturer.[10]

 

Figure  Chemical structures of salmeterol, formoterol, inda- caterol, and emerging once-daily long-acting β2-agonists

 

CLIP

Synthetic approaches to the 2013 new drugs – ScienceDirect

Science Direct

Synthesis of olodaterol hydrochloride (XVI).

Image result for OLODATEROL DRUG FUTURE

Olodaterol hydrochloride was approved for long-term, once-daily maintenance treatment of chronic
obstructive pulmonary disease (COPD) in 2013 in the following countries: Canada, Russia, United
Kingdom, Denmark, and Iceland.142, 143 The drug has been recommended by a federal advisory panel for
approval by the FDA.142, 143 Developed and marketed by Boehringer Ingelheim, olodaterol is a longacting
β2-adrenergic receptor agonist with high selectivity over the β1- and β3-receptors (219- and 1622-fold, respectively).144 Upon binding to and activating the β2-adrenergic receptor in the airway, olodaterol
stimulates adenyl cyclase to synthesize cAMP, leading to the relaxation of smooth muscle cells in the
airway. Administered by inhalation using the Respimat®
Soft Mist inhaler, it delivers significant
bronchodilator effects within five minutes of the first dose and provides sustained improvement in
forced expiratory volume (FEV1) for over 24 hours.143 While several routes have been reported in the
patent and published literature,144-146 the manufacturing route for olodaterol hydrochloride disclosed in
2011 is summarized in Scheme 19 below.147
Commercial 2’,5’-dihydroxyacetophenone (122) was treated with one equivalent of benzyl bromide
and potassium carbonate in methylisobutylketone (MIBK) to give the 5’-monobenzylated product in
76% yield. Subsequent nitration occurred at the 4’-position to provide nitrophenol 123 in 87% yield.
Reduction of the nitro group followed by subjection to chloroacetyl chloride resulted in the construction
of benzoxazine 124 in 82% yield. Next, monobromination through the use of tetrabutylammonium
tribromide occurred at the acetophenone carbon to provide bromoketone 125, and this was followed by
asymmetric reduction of the ketone employing (−)-DIP chloride to afford an intermediate bromohydrin,
which underwent conversion to the corresponding epoxide 126 in situ upon treatment with aqueous
NaOH. This epoxide was efficiently formed in 85% yield and 98.3% enantiomeric excess. Epoxide
126 underwent ring-opening upon subjection to amine 127 to provide amino-alcohol 128 in in 84-90%
yield and 89.5-99.5% enantiomeric purity following salt formation with HCl. Tertiary amine 127 was
itself prepared in three steps by reaction of ketone 129 with methylmagnesium chloride, Ritter reaction
of the tertiary alcohol with acetonitrile, and hydrolysis of the resultant acetamide with ethanolic
potassium hydroxide. Hydrogenative removal of the benzyl ether within 128 followed by
recrystallization with methanolic isopropanol furnished olodaterol hydrochloride (XVI) in 63-70%
yield. Overall, the synthesis of olodaterol hydrochloride required 10 total steps (7 linear) from
commercially available acetophenone 122.

142. Gibb, A.; Yang, L. P. H. Drugs 2013, 73, 1841.
143. http://www.boehringeringelheim.com/news/news_releases/press_releases/2013/18_october_2013_olodaterol.html.

144. Bouyssou, T.; Hoenke, C.; Rudolf, K.; Lustenberger, P.; Pestel, S.; Sieger, P.; Lotz, R.; Heine,
C.; Buettner, F. H.; Schnapp, A.; Konetzki, I. Bioorg. Med. Chem. Lett. 2010, 20, 1410.
145. Trunk, M. J. F.; Schiewe, J. US Patent 20050255050A1, 2005.
146. Lustenberger, P.; Konetzki, I.; Sieger, P. US Patent 20090137578A1, 2009.
147. Krueger, T.; Ries, U.; Schnaubelt, J.; Rall, W.; Leuter, Z. A.; Duran, A.; Soyka, R. US Patent
20110124859A1, 2011.

 

PATENT

WO 2004045618 or

http://www.google.com/patents/EP1562603B1?cl=en

Example

 

Figure imgb0006

a)

To a solution of 3.6 g 1,1-dimethyl-2-(4-methoxyphenyl)-ethylamine in 100 mL of ethanol at 70 ° C. 7.5 g of (6-benzyloxy-4H-benzo [1,4] oxazin-3-one )-glyoxal added and allowed to stir for 15 minutes. Then within 30 minutes at 10 to 20 ° C. 1 g of sodium borohydride added. It is stirred for one hour, with 10 mL of acetone and stirred for another 30 minutes. The reaction mixture is diluted with 150 mL ethyl acetate, washed with water, dried with sodium sulfate and concentrated. The residue is dissolved in 50 mL of methanol and 100 mL ethyl acetate and acidified with conc. Hydrochloric acid. After addition of 100 mL of diethyl ether, the product precipitates. The crystals are filtered, washed and recrystallized from 50 mL of ethanol. Yield: 7 g (68%; hydrochloride), mp = 232-234 ° C.

b)

6.8 g of the above obtained benzyl compound in 125 mL of methanol with the addition of 1 g of palladium on carbon (5%) was hydrogenated at room temperature and normal pressure. The catalyst is filtered and the filtrate was freed from solvent. Recrystallization of the residue in 50 mL of acetone and a little water, a solid is obtained, which is filtered and washed.
Yield: 5.0 g (89%; hydrochloride), mp = 155-160 ° C.

The (R) – and (S)-enantiomers of Example 3 can be obtained from the racemate, for example, by chiral HPLC (for example, column: Chirobiotic T, 250 x 1.22 mm from the company Astec). As the mobile phase, methanol with 0.05% triethylamine and 0.05% acetic acid. Silica gel with a grain size of 5 microns, to which is covalently bound the glycoprotein teicoplanin can reach as column material used. Retention time (R enantiomer) = 40.1 min, retention time (S-enantiomer) = 45.9 min. The two enantiomers can be obtained by this method in the form of free bases. According to the invention of paramount importance is the R enantiomer of Example 3

 

 

PATENT

WO 2005111005

http://www.google.fm/patents/WO2005111005A1?cl=en

Scheme 1.

 

Figure imgf000013_0001

 

Figure imgf000013_0003
Figure imgf000013_0002

 

Figure imgf000013_0004

Scheme 1:

Example 1 6-Hydroxy-8-{(1-hydroxy-2-r2-(4-methoxy-phenyl) – 1, 1-dimethyl-ethylamino]-ethyl)-4H-benzor 41oxazin-3-one – Hvdrochlorid

 

Figure imgf000017_0001

a) l-(5-benzyloxy-2-hydroxy-3-nitro-phenyl)-ethanone

To a solution of 81.5 g (0.34 mol) l-(5-benzyloxy-2-hydroxy-phenyl)-ethanone in 700 ml of acetic acid are added dropwise under cooling with ice bath, 18 mL of fuming nitric acid, the temperature does not exceed 20 ° C. increases. The reaction mixture is stirred for two hours at room temperature, poured onto ice water and filtered. The product is recrystallized from isopropanol, filtered off and washed with isopropanol and diisopropyl ether. Yield: 69.6 g (72%), mass spectroscopy [M + H] + = 288

b) l-(3-Amino-5-benzyloxy-2-hydroxy-phenyl)-ethanone

69.5 g (242 mmol) of l-(5-benzyloxy-2-hydroxy-3-nitro-phenyl)-ethanone are dissolved in 1.4 L of methanol and in the presence of 14 g of rhodium on carbon (10%) as catalyst at 3 bar room temperature and hydrogenated. Then the catalyst is filtered off and the filtrate concentrated. The residue is reacted further without additional purification. Yield: 60.0 g (96%), R f value = 0.45 (silica gel, dichloromethane).

c) 8-acetyl-6-benzyloxy-4H-benzoπ .4] oxazin-3-one

To 60.0 g (233 mmol) of l-(3-Amino-5-benzyloxy-2-hydroxy-phenyl)-ethanone and 70.0 g (506 mmol) of potassium carbonate while cooling with ice bath, 21.0 ml (258 mmol) of chloroacetyl chloride added dropwise. Then stirred overnight at room temperature and then for 6 hours under reflux. The hot reaction mixture is filtered and then concentrated to about 400 mL and treated with ice water. The precipitate is filtered off, dried and purified by chromatography on a short silica gel column (dichloromethane: methanol = 99:1). The product-containing fractions are concentrated, suspended in isopropanol, diisopropyl ether, and extracted with

Diisopropyl ether. Yield: 34.6 g (50%), mass spectroscopy [M + H] + = 298

d) 6-Benzyloxy-8-(2-chloro-acetyl)-4H-benzoFl, 4] oxazin-3-one 13.8 g (46.0 mmol) of 8-benzyloxy-6-Acetyl-4H-benzo [l, 4] oxazin -3-one and 35.3 g (101.5 mmol) of benzyltrimethylammonium dichloriodat are stirred in 250 mL dichloroethane, 84 mL glacial acetic acid and 14 mL water for 5 hours at 65 ° C. After cooling to room temperature, treated with 5% aqueous sodium hydrogen sulfite solution and stirred for 30 minutes. The precipitated solid is filtered off, washed with water and diethyl ether and dried. Yield: 13.2 g (86%), mass spectroscopy [M + H] + = 330/32.

e) 6-Benzyloxy-8-((R-2-chloro-l-hydroxy-ethyl)-4H-benzori ,41-oxazin-3-one The procedure is analogous to a procedure described in the literature (Org. Lett ., 2002, 4, 4373-4376).

To 13:15 g (39.6 mmol) of 6-benzyloxy-8-(2-chloro-acetyl)-4H-benzo [l, 4] oxazin-3-one and 25.5 mg (0:04 mmol) Cρ * RhCl [(S, S) -TsDPEN] (Cp * = pentamethylcyclopentadienyl and TsDPEN = (lS, 2S)-Np-toluenesulfonyl-l ,2-diphenylethylenediamine) in 40 mL of dimethylformamide at -15 ° C and 8 mL of a mixture of formic acid and triethylamine (molar ratio = 5: 2) dropwise. It is allowed for 5 hours at this temperature, stirring, then 25 mg of catalyst and stirred overnight at -15 ° C. The reaction mixture is mixed with ice water and filtered. The filter residue is dissolved in dichloromethane, dried with sodium sulfate and the solvent evaporated. The residue is recrystallized gel (dichloromethane / methanol gradient) and the product in diethyl ether / diisopropyl ether. Yield: 10.08 g (76%), R f value = 00:28 (on silica gel, dichloromethane ethanol = 50:1).

f) 6-Benzyloxy-8-(R-oxiranyl-4H-benzo [“L4] oxazin-3-one 6.10 g (30.1 mmol) of 6-benzyloxy-8-((R)-2-chloro-l-hydroxy- ethyl)-4H-benzo [l, 4] oxazin-3-one are dissolved in 200 mL of dimethylformamide. added to the solution at 0 ° C with 40 mL of a 2 molar sodium hydroxide solution and stirred at this temperature for 4 hours. the reaction mixture is poured onto ice water, stirred for 15 minutes, and then filtered The solid is washed with water and dried to give 8.60 g (96%), mass spectroscopy [M + H] + = 298..

g) 6-Benyloxy-8-{(R-l-hydroxy-2-r2-(4-methoxy-phenyl)-dimethyl-ll-ethvIaminol-ethyl)-4H-benzo-3-Tl A1oxazin

5.25 g (17.7 mmol) of 6-benzyloxy-8-(R)-oxiranyl-4H-benzo [l, 4] oxazin-3-one and 6.30 g (35.1 mmol) of 2 – (4-methoxy-phenyl 1, 1 – dimethyl-ethyl to be with 21 mL

Of isopropanol and stirred at 135 ° C for 30 minutes under microwave irradiation in a sealed reaction vessel. The solvent is distilled off and the residue chromatographed (alumina, ethyl acetate / methanol gradient). The product thus obtained is purified by recrystallization from a mixture further Diethylether/Diisopropylether-. Yield: 5:33 g (63%), mass spectroscopy [M + H] + = 477 h) 6-Hydroxy-8-{(R)-l-hydroxy-2-[2 – (4-methoxy-phenyl)-l, l-dimethyl-ethylamino] – ethyl}-4H-benzo [1, 4, 1 oxazin-3-one hydrochloride

A suspension of 5:33 g (11.2 mmol) of 6-Benyloxy-8-{(R)-l-hydroxy-2-[2 – (4-methoxy-phenyl)-l, l-dimethyl-ethylamino]-ethyl}-4H -benzo [l, 4] oxazin-3-one in 120 mL of methanol with 0.8 g of palladium on carbon (10%), heated to 50 ° C and hydrogenated at 3 bar hydrogen pressure. Then the catalyst is filtered off and the filtrate concentrated. The residue is dissolved in 20 mL of isopropanol, and 2.5 mL of 5 molar hydrochloric acid in isopropanol. The product is precipitated with 200 mL of diethyl ether, filtered off and dried. Yield: 4.50 g (95%, hydrochloride), mass spectroscopy [M + H] + = 387

 

PATENT

WO 2007020227

http://www.google.com.ar/patents/WO2007020227A1?cl=en

 

PATENT

WO 2008090193

or

http://www.google.com/patents/EP2125759B1?cl=en

 

PAPER

Discovery of olodaterol, a novel inhaled beta(2)-adrenoceptor agonist with a 24h bronchodilatory efficacy
Bioorg Med Chem Lett 2010, 20(4): 1410

 http://www.sciencedirect.com/science/article/pii/S0960894X09018101

The discovery of the β2-adrenoceptor agonist (R)-4p designated olodaterol is described. The preclinical profile of the compound suggests a bronchoprotective effect over 24 h in humans.

Full-size image (4 K)

CLIP

 

Australia

http://www.tga.gov.au/pdf/auspar/auspar-olodaterol-140327-pi.pdf

 

CLIP

DUTCH

http://mri.medagencies.org/download/NL_H_2498_001_PAR.pdf

FDA

https://www.accessdata.fda.gov/drugsatfda_docs/nda/2014/203108Orig1s000ChemR.pdf

NDA 203108
Striverdi® Respimat® (olodaterol) Inhalation Spray
Boehringer Ingelheim Pharmaceuticals, Inc.

References

  1. Striverdi UK Drug Information
  2. Bouyssou, T.; Casarosa, P.; Naline, E.; Pestel, S.; Konetzki, I.; Devillier, P.; Schnapp, A. (2010). “Pharmacological Characterization of Olodaterol, a Novel Inhaled  2-Adrenoceptor Agonist Exerting a 24-Hour-Long Duration of Action in Preclinical Models”. Journal of Pharmacology and Experimental Therapeutics 334 (1): 53–62. doi:10.1124/jpet.110.167007. PMID 20371707. edit
  3. Casarosa, P.; Kollak, I.; Kiechle, T.; Ostermann, A.; Schnapp, A.; Kiesling, R.; Pieper, M.; Sieger, P.; Gantner, F. (2011). “Functional and Biochemical Rationales for the 24-Hour-Long Duration of Action of Olodaterol”. Journal of Pharmacology and Experimental Therapeutics 337 (3): 600–609. doi:10.1124/jpet.111.179259. PMID 21357659. edit
  4. Bouyssou, T.; Hoenke, C.; Rudolf, K.; Lustenberger, P.; Pestel, S.; Sieger, P.; Lotz, R.; Heine, C.; Büttner, F. H.; Schnapp, A.; Konetzki, I. (2010). “Discovery of olodaterol, a novel inhaled β2-adrenoceptor agonist with a 24h bronchodilatory efficacy”. Bioorganic & Medicinal Chemistry Letters 20 (4): 1410–1414. doi:10.1016/j.bmcl.2009.12.087. PMID 20096576. edit
  5. Joos G, Aumann JL, Coeck C, et al. ATS 2012 Abstract: Comparison of 24-Hour FEV1 Profile for Once-Daily versus Twice-Daily Treatment with Olodaterol, A Novel Long-Acting ß2-Agonist, in Patients with COPD[dead link]
  6. Van Noord, J. A.; Smeets, J. J.; Drenth, B. M.; Rascher, J.; Pivovarova, A.; Hamilton, A. L.; Cornelissen, P. J. G. (2011). “24-hour Bronchodilation following a single dose of the novel β2-agonist olodaterol in COPD”. Pulmonary Pharmacology & Therapeutics 24 (6): 666–672. doi:10.1016/j.pupt.2011.07.006. PMID 21839850. edit
  7. van Noord JA, Korducki L, Hamilton AL and Koker P. Four Weeks Once Daily Treatment with BI 1744 CL, a Novel Long-Acting ß2-Agonist, is Effective in COPD Patients. Am. J. Respir. Crit. Care Med. 2009; 179: A6183[dead link]
  8. Haberfeld, H, ed. (2009). Austria-Codex (in German) (2009/2010 ed.). Vienna: Österreichischer Apothekerverlag. ISBN 3-85200-196-X.
  9. Hollis A (31 January 2013). “Panel Overwhelmingly Supports Boehringer COPD Drug Striverdi”. FDA News/Drug Industry Daily.
  10. “New once-daily Striverdi (olodaterol) Respimat gains approval in first EU countries”. Boehringer-Ingelheim. 18 October 2013.

External links

The active moiety olodaterol is a selective beta2-adrenergic bronchodilator. The drug substance, olodaterol hydrochloride, is chemically described as 2H-1,4- Benzoxazin-3H(4H)-one, 6-hydroxy-8-[(1R)-1-hydroxy-2-[[2-(4-methoxyphenyl)-1,1-dimethylethyl]-amino]ethyl]-, monohydrochloride. Olodaterol hydrochloride is a white to off-white powder that is sparingly-slightly soluble in water and slightly soluble in ethanol. The molecular weight is 422.9 g/mole (salt): 386.5 g/mole (base), and the molecular formula is C21H26N2O5 x HCl as a hydrochloride. The conversion factor from salt to free base is 1.094.

The structural formula is:

STRIVERDI® RESPIMAT® (olodaterol) Structural Formula Illustration

The drug product, STRIVERDI RESPIMAT, is composed of a sterile, aqueous solution of olodaterol hydrochloride filled into a 4.5 mL plastic container crimped into an aluminum cylinder (STRIVERDI RESPIMAT cartridge) for use with the STRIVERDI RESPIMAT inhaler.

Excipients include water for injection, benzalkonium chloride, edetate disodium, and anhydrous citric acid. The STRIVERDI RESPIMAT cartridge is only intended for use with the STRIVERDI RESPIMAT inhaler. The STRIVERDI RESPIMAT inhaler is a hand held, pocket sized oral inhalation device that uses mechanical energy to generate a slow-moving aerosol cloud of medication from a metered volume of the drug solution. The STRIVERDI RESPIMAT inhaler has a yellow-colored cap.

When used with the STRIVERDI RESPIMAT inhaler, each cartridge containing a minimum of 4 grams of a sterile aqueous solution delivers the labeled number of metered actuations after preparation for use. Each dose (1 dose equals 2 actuations) from the STRIVERDI RESPIMAT inhaler delivers 5 mcg olodaterol in 22.1 mcL of solution from the mouthpiece. As with all inhaled drugs, the actual amount of drug delivered to the lung may depend on patient factors, such as the coordination between the actuation of the inhaler and inspiration through the delivery system. The duration of inspiration should be at least as long as the spray duration (1.5 seconds).

 

WO2002030928A1 28 Sep 2001 11 Apr 2003 Boehringer Ingelheim Pharma Crystalline monohydrate, method for producing the same and the use thereof in the production of a medicament
WO2003000265A1 8 Jun 2002 3 Jan 2003 Boehringer Ingelheim Pharma Crystalline anticholinergic, method for its production, and use thereof in the production of a drug
WO2004045618A2 * 11 Nov 2003 3 Jun 2004 Boehringer Ingelheim Pharma Novel medicaments for the treatment of chronic obstructive pulmonary diseases
EP0073505A1 * 28 Aug 1982 9 Mar 1983 Boehringer Ingelheim Kg Benzo-heterocycles
EP0321864A2 * 15 Dec 1988 28 Jun 1989 Boehringer Ingelheim Kg Ammonium compounds, their preparation and use
US4460581 12 Oct 1982 17 Jul 1984 Boehringer Ingelheim Kg Antispasmodic agents, antiallergens
US4656168 * 13 Oct 1983 7 Apr 1987 Merck & Co., Inc. Vision defects; adrenergic blocking and hypotensive agents

 

Organic spectroscopy should be brushed up and you get confidence

read my blog

 

Organic chemists from Industry and academics to interact on Spectroscopy techniques for Organic compounds ie NMR, MASS, IR, UV Etc. email me ……….. amcrasto@gmail.com

http://orgspectroscopyint.blogspot.in/  is the link

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How to Handle Drug Polymorphs… Case Study of Trelagliptin Succinate


Pharmaceutical API Polymorphs… case study of Trelagliptin
CASE STUDY WITH..Compound I having the formula
Figure imgf000073_0001
Links
WO2008067465A1 OR US8084605  IS THE PATENT USED AND WITH FORM “A” AND AMORPHOUS FORM
Active pharmaceutical ingredients (APIs), frequently delivered to the patient in the solid-state as part of an approved dosage form, can exist in such diverse solid forms as polymorphs, pseudopolymorphs, salts, co-crystals and amorphous solids. Various solid forms often display different mechanical, thermal, physical and chemical properties that can remarkably influence the bioavailability, hygroscopicity, stability and other performance characteristics of the drug.
Hence, a thorough understanding of the relationship between the particular solid form of an active pharmaceutical ingredient (API) and its functional properties is important in selecting the most suitable form of the API for development into a drug product. In past decades, there have been significant efforts on the discovery, selection and control of the solid forms of APIs and bulk drugs.

If you’re involved in late drug discovery, API manufacture, drug product formulation, clinical material production, or manufacture of final dosage form, a basic understanding and awareness of solid form issues could save you a great deal of difficulty, time, and money during drug development.

 
What is polymorphism?
Polymorphs are crystalline materials that have the same chemical composition but different molecular packing. The concept is well demonstrated by the different crystalline forms of carbon. Diamond, graphite, and fullerenes are all made of pure carbon, but their physical and chemical properties vary drastically. Polymorphs are one type of solid form. Other solid form types include solvates, hydrates, and amorphous forms.
Solvates are crystalline materials made of the same chemical substance, but with molecules of solvent regularly incorporated into a unique molecular packing. When water is the solvent, these are called hydrates. An amorphous form of a substance has the same chemical composition, but lacks the long-range molecular order of a crystalline form of the same substance. Many organic and inorganic compounds, including APIs, can exist in multiple solid forms.
Some APIs may have only one or two known solid forms. Others may exist in twenty different forms, each having different physical and chemical properties.
Solid form screening, including salt, polymorph, cocrystal and amorphous solid dispersions, is vitial for successful pharmaceutical development. With an increase in the size and complexity of the molecules that enter into drug development, companies face a larger number of compounds that are either poorly soluble, difficult to crystallize or problematic with respect to desired physical chemical properties hindering successful drug development.
Crystallics has an extensive track record in executing solid state research studies and its research team has a broad expertise in identifying new crystal forms as well as in solving problems related to polymorphism and crystallization.

Investigational new drug, writing an application for clinical trial authorization, permission marketing …The control of polymorphism in drug candidates is now ubiquitous.

Links

READ………….An Overview of Solid Form Screening During Drug Development, http://www.icdd.com/ppxrd/10/presentations/PPXRD-10_Ann_Newman.pdf

ANN NEWMAN

When addressing the subject of polymorphism, the first reference that comes to mind is that of the occurred during the manufacture of ritonavir incident. Abbott molecule inhibitor of HIV protease marketed as Norvir, is a cautionary example of the challenges of polymorphism. 

Indeed, during the production of ritonavir in 1997, a new polymorph unmarked emerged. Its precipitation and unexpected outbreak led to the cessation of the production of Norvir and seriously compromise the process. The incident has deeply marked the pharmaceutical industry.

It is ironic that the process used to discover pharmaceutical drug targets is the same one that decreases the actual efficacy of those drugs once ingested. If you remember from basic chemistry, there are compounds that exist in highly ordered crystalline states and those that remain in amorphous form.

The discovery of drug targets has often been accomplished through X-ray crystallography, which requires a sample (for example, of a defective enzyme linked to cancer or high cholesterol) to be crystallized so that the diffraction patterns can be made sense of. Scientists may spend years trying to crystallize one molecule or compound so that they can identify regions that, for example, may be blocked by pharmaceuticals.

However, when it comes to the molecular arrangement of those pharmaceuticals, crystallization actually decreases their bioavailability and solubility. Thus, it may be better for these drugs to be in amorphous form. Pierric Marchand, general manager of the company Holodiag, dedicated to the study and characterization of solid state, summarizes that ” today, it is not reasonable to not worry about the problem of polymorphism ” .

” In recent years, manufacturers have realized the essential side of expertise , “says Jean-Rémi David, commercial director Calytherm. The services company specializing in the field of physico-chemical analysis, based in Herault, has just relocated last year in supporting pharmaceutical development to meet demand. ” This is a concern for all deal with potential impacts on the effectiveness or the formulation , “says Stéphane Suchet, quality manager in the group of fine and specialty chemicals Axyntis.

Polymorphic forms are the amorphous and crystalline forms such as hydrate or solvate forms. When a molecule of interest exists in polymorphic forms, it is called polymorphism, according to the definition of the FDA (Food and Drug Administration).

Polymorphism is present at all stages of development of a drug from research to marketing. ” Keep in mind that organic molecule loves to polymorphism , “says Marchand Pierric. However, for a marketing authorization for example, must learn the criteria for the polymorphism of the molecule. ” In terms of the formulation, for example we can check whether the selected polymorphism is unchanged , “explains Pierric Marchand.

A significant influence on several levels  Because the consequences of polymorphism are multiple. ” They are at three levels: bioequivalence, manufacturability and stability “lists Fabienne Lacoulonche, founder and scientific director of Calytherm.In terms of bioequivalence, different polymorphic forms may have different properties of solubility and dissolution rate … ” For poorly soluble active ingredients, you can have much more bioavailable than other crystalline forms , “Fabienne Lacoulonche information.

In terms of manufacturability, some parameters such as temperature, moisture can lead to changes in the crystalline form. ” The complexity is to anticipate changes polymorphism, both at laboratory scale, pilot and industrial , “adds the founder of Calytherm. Finally, polymorphism plays on stability. Active ingredient or finished product, are subjected to stability studies in this direction. ” When the molecule is identified, we try to highlight the existence of several forms of polymorphism, explains Stéphane Suchet (Axyntis) 

When developing a new substance, the assessment is systematic . ” Isolation of crystals from a screening is carried out in different solvents by various analytical techniques. Ideally, it will be concluded the absence of polymorphism. ” But if different polymorphic forms are present, we rework the terms of our crystallization process to control the formation of the same polymorph reproducibly ideally form the thermodynamically more stable , “says Stéphane Suchet. X-ray diffraction and other thermal analysis ”

The ICH guidelines provide decision trees to guide the industry in controlling polymorphism says Fabienne Lacoulonche (Calytherm.) We use it for writing the CTD (Common Technical Document) .

“Polymorphism is a phenomenon” complex and difficult to control, because the crystallization is dependent on many parameters , she develops. must understand the maximum . ” For this, several analytical methods are available to industry. The main technique is the X-ray diffraction ” It is a robust, rapid, which allows to characterize the different polymorphs , “summarizes Pierric Marchand (Holodiag).Non-destructive, it can work both on small quantities on large samples. Temperature and atmosphere are controlled, and analytical capabilities are broad.

But if this technique indispensable allows for routine and development, it is not sufficient in itself. Just to add a battery of additional tests, thermal analysis. ” It takes coupling methods “ confirms Fabienne Lacoulonche (Calytherm). The X-ray diffraction is a method of choice, but sometimes it is not sufficient.

The coupling with a thermal analysis method (technical ATG, or DSC thermal analysis, differential scanning calorimetry or thermomicroscopique) allows to distinguish between two polymorphic whose RX diffractograms obtained are comparable.

TGA can be coupled with IR or mass spectrometry, DSC with RX. Raman spectroscopy is also part of complementary methods. ” The difficulty increases when we want to characterize the shape of the active ingredient in the finished product , says Fabienne Lacoulonche. example, by X-ray diffraction, the peaks related to the active ingredient in the diffractogram of the finished product may be masked by those excipients: it is then necessary to use other methods, such as Raman microscopy. “In general, a single method of analysis is not sufficient to characterize the polymorphism of an active substance in the active substance or finished product: the complementarity of different methods that will conclude precisely on the polymorphism of a crystalline substance.

In addition, ” the diffractometer remains an expensive device, which requires installation in an air-conditioned and a cooling room , “says Marchand Pierric (Holodiag). To this is added the need to have expertise and qualified personnel to carry out the analyzes. ” We must master these techniques and the ability to interpret the results , “says Jean-Rémi David (Calytherm). However, polymorphism is a “problem well under control , “said Stéphane Suchet (Axyntis),” systematically evaluated although it is however not always immune to miss a polymorphic form, knowing that the screening performed in the development can never be completely comprehensive … ”

FDA

FDA may refuse to approve an ANDA referencing a listed drug if the application contains insufficient information to show that the drug substance is the “same” as that of the reference listed drug. A drug substance in a generic drug product is generally considered to be the same as the drug substance in the reference listed drug if it meets the same standards for identity.

In most cases, the standards for identity are described in the USPalthough FDA may prescribe additional standards when necessary. Because drug product performance depends on the product formulation, the drug substance in a proposed generic drug product need not have the same physical form (particle size, shape, or polymorph form) as the drug substance in the reference listed drug. An ANDA applicant is required to demonstrate that the proposed product meets the standards for identity, exhibits sufficient stability and is bioequivalent to the reference listed drug.

Links

FDA PRESENTATION……polymorphs and co-crystals – ICDD      Regulatory Considerations on Pharmaceutical Solids: Polymorphs/Salts and Co-Crystals.. THIS IS A MUST READ ITEM

Over the years FDA has approved many generic drug products based upon a drug substance with different physical form from that of the drug substance in the respective reference listed drug (e.g., warfarin sodium, famotidine, and ranitidine). Also many ANDAs have been approved in which the drug substances differed from those in the corresponding reference listed drugs with respect to solvation or hydration state (e.g., terazosin hydrochloride, ampicillin, and cefadroxil). Several regulatory documents and literature reports (67-69) address issues relevant to the regulation of polymorphism.

The concepts and principles outlined in these are applicable for an ANDA. However, certain additional considerations may be applicable in case of ANDAs. Often at the time FDA receives an ANDA a monograph defining certain key attributes of the drug substance and drug product may be available in the Unites States Pharmacopoeia (USP). These public standards play a significant role in the ANDA regulatory review process and in case of polymorphism, when some differences are noted, lead to additional requirements and considerations.

This commentary is intended to provide a perspective on polymorphism in pharmaceutical solid in the context of ANDAs. It highlights major considerations for monitoring and controlling drug substance polymorphs and describes a framework for regulatory decisions regarding drug substance “sameness” considering the role and impact of polymorphism in pharmaceutical solids.

Since polymorphs exhibit certain differences in physical (e.g., powder flow and compactability, apparent solubility and dissolution rate) and solid state chemistry (reactivity) attributes that relate to stability and bioavailability it is essential that the product development and the FDA review process pay close attention to this issue.

This scrutiny is essential to ensure that polymorphic differences (when present) are addressed via design and control of formulation and process conditions to physical and chemical stability of the product over the intended shelf-life, and bioavailability/bioequivalence.

Most pharmaceuticals are distributed as solid doseages. In order to take action, they must dissolve in the gut and be absorbed into the blood stream. In many cases, the rate at which the drug dissolves can limit its effectiveness. Pharmaceutical compounds can be packed into more than one arrangement in the solid states known as polymorphs. Rapid and efficient methods of polymorph formation can be used to increase drug efficacy and shelf life.

Regulatory agencies worldwide require that, as part of any significant filing, a company has to demonstrate that it has made a reasonable effort to identify the polymorphs of their drug substance and has checked for polymorph interconversions. Due to the unpredictable behaviour of polymorphs and their respective differences in physicochemical properties, companies also have to demonstrate consistency in manufacturing between batches of the same product. Proper understanding of the polymorph landscape and nature of the polymorphs will contribute to manufacturing consistency.

Links

POLYMORPHISM AND PATENTS http://www.collegio.unibo.it/uploads/ideas/joelbernstein.pdf  A MUST CLICK FOR PHARMA CHEMISTS

Triclinic Labs approach to solid-state (solid form) screening and selection for optimal properties of an active pharmaceutical ingredient

Links

READ………..High-throughput crystallization: polymorphs, salts, co-crystalsand solvates of pharmaceutical solidshttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.85.5397&rep=rep1&type=pdf

Definitions

“Crystalline”, as the term is used herein, refers to a material, which may be hydrated and/or solvated, and has sufficient ordering of the chemical moiety to exhibit a discernable diffraction pattern by XRPD or other diffraction techniques. Often, a crystalline material that is obtained by direct crystallization of a compound dissolved in a solution or by interconversion of crystals obtained under different crystallization conditions, will have crystals that contain the solvent used in the crystallization, termed a crystalline solvate. Also, the specific solvent system and physical embodiment in which the crystallization is performed, collectively termed crystallization conditions, may result in the crystalline material having physical and chemical properties that are unique to the crystallization conditions, generally due to the orientation of the chemical moieties of the compound with respect to each other within the crystal and/or the predominance of a specific polymorphic form of the compound in the crystalline material.

Depending upon the polymorphic form(s) of the compound that are present in a composition, various amounts of the compound in an amorphous solid state may also be present, either as a side product of the initial crystallization, and/or a product of degradation of the crystals comprising the crystalline material. Thus, crystalline, as the term is used herein, contemplates that the composition may include amorphous content; the presence of the crystalline material among the amorphous material being detectably among other methods by the composition having a discernable diffraction pattern.

The amorphous content of a crystalline material may be increased by grinding or pulverizing the material, which is evidenced by broadening of diffraction and other spectral lines relative to the crystalline material prior to grinding. Sufficient grinding and/or pulverizing may broaden the lines relative to the crystalline material prior to grinding to the extent that the XRPD or other crystal specific spectrum may become undiscernable, making the material substantially amorphous or quasi-amorphous. Continued grinding would be expected to increase the amorphous content and further broaden the XRPD pattern with the limit of the XRPD pattern being so broadened that it can no longer be discerned above noise. When the XRPD pattern is broadened to the limit of being indiscernible, the material may be considered no longer a crystalline material, but instead be wholly amorphous. For material having increased amorphous content and wholly amorphous material, no peaks should be observed that would indicate grinding produces another form.

“Amorphous“, as the term is used herein, refers to a composition comprising a compound that contains too little crystalline content of the compound to yield a discernable pattern by XRPD or other diffraction techniques. Glassy materials are a type of amorphous material. Glassy materials do not have a true crystal lattice, and technically resembling very viscous non-crystalline liquids. Rather than being true solids, glasses may better be described as quasi-solid amorphous material. “Broad” or “broadened”, as the term is used herein to describe spectral lines, including XRPD, NMR and IR spectroscopy, and Raman spectroscopy lines, is a relative term that relates to the line width of a baseline spectrum. The baseline spectrum is often that of an unmanipulated crystalline form of a specific compound as obtained directly from a given set of physical and chemical conditions, including solvent composition and properties such as temperature and pressure.

For example, broadened can be used to describe the spectral lines of a XRPD spectrum of ground or pulverized material comprising a crystalline compound relative to the material prior to grinding. In materials where the constituent molecules, ions or atoms, as solvated or hydrated, are not tumbling rapidly, line broadening is indicative of increased randomness in the orientation of the chemical moieties of the compound, thus indicative of an increased amorphous content. When comparisons are made between crystalline materials obtained via different crystallization conditions, broader spectral lines indicate that the material producing the relatively broader spectral lines has a higher level of amorphous material.

“About” as the term is used herein, refers to an estimate that the actual value falls within ±5% of the value cited. “Forked” as the term is used herein to describe DSC endotherms and exotherms, refers to overlapping endotherms or exotherms having distinguishable peak positions

.

Classes of multicomponent pharmaceutical materials. (a) Schematic of crystalline materials showing neutral and charged species. The red box indicates polymorphs are possible for all the multicomponent crystals contained within the box (adapted from Reference 7). (b) Schematic of amorphous solid dispersions showing binary, ternary, and quaternary possibilities for polymers and surfactants. Other solubilization techniques using cyclodextrins and phospholipids are included for completeness but have a different mechanism for solubilization when compared to polymer and surfactant systems.

The red box indicates that properties can change with water or solvent content. General methods for precipitating and crystallizing a compound may be applied to prepare the various polymorphs described herein. These general methods are known to those skilled in the art of synthetic organic chemistry and pharmaceutical formulation, and are described, for example, by J. March, “Advanced Organic Chemistry: Reactions, Mechanisms and Structure ” 4th Ed. (New York: Wiley-Interscience, 1992).

In general, a given polymorph of a compound may be obtained by direct crystallization of the compound or by crystallization of the compound followed by inter-conversion from another polymorphic form or from an amorphous form. Depending on the method by which a compound is crystallized, the resulting composition may contain different amounts of the compound in crystalline form as opposed to as an amorphous material.

Also, the resulting composition may contain differing mixtures of different polymorphic forms of the compound. Compositions comprising a higher percentage of crystalline content {e.g., forming crystals having fewer lattice defects and proportionately less glassy material) are generally prepared when using conditions that favor slower crystal formation, including slow solvent evaporation and those affecting kinetics.

Crystallization conditions may be appropriately adjusted to obtain higher quality crystalline material as necessary. Thus, for example, if poor crystals are formed under an initial set of crystallization conditions, the solvent temperature may be reduced and ambient pressure above the solution may be increased relative to the initial set of crystallization conditions in order to slow down crystallization. Precipitation of a compound from solution, often affected by rapid evaporation of solvent, is known to favor the compound forming an amorphous solid as opposed to crystals. A compound in an amorphous state may be produced by rapidly evaporating solvent from a solvated compound, or by grinding, pulverizing or otherwise physically pressurizing or abrading the compound while in a crystalline state.

Seven crystalline forms and one amorphous solid were identified by conducting a polymorph screen (Example 3). Described herein are Form A, Form B, Form C, Form D, Form E, Form F, Form G, and Amorphous Form of Compound I. Where possible, the results of each test for each different polymorph are provided. Forms A, C, D and E were prepared as pure forms. Forms B, F, and G were prepared as mixtures with Form A.
Various tests were performed in order to physically characterize the polymorphs of Compound I including X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), hot stage microscopy, Fourier transform infrared spectroscopy (FT-IR), Fourier transform Raman spectrometry, linked thermogravimetric-infrared spectroscopy (TG-IR), solution proton nuclear magnetic resonance (1H-NMR), solid state 13carbon nuclear magnetic resonance (13C-NMR), and moisture sorption and desorption analysis (M S/Des).

 

Salt screening

Physicochemical properties of drug substances, such as solubility, dissolution rate, and physicochemical stability can be altered significantly by salt formation. Consequently, important properties of the drug product such as bioavailability or shelve life can be radically influenced. Crystallics’ technology platform for crystallization screening accommodates salt screening studies using only minimal amounts of drug substance while still performing a large number of experiments. High-throughput salt screening is used for both early phase salt selection studies and broad patent protection.

Salt selection – A powerful strategy for crystal form optimization

Pharmaceutical developers have focused efforts on finding and formulating a thermodynamically stable crystalline form with acceptable physical properties for a given compound. This is reasonable, given the need to avoid cascading from a meta-stable form to a more stable one in unpredictable fashion.

Occasionally certain physical properties, such as low aqueous solubility, are limiting to performance of the compound, leading to poor oral bioavailability or insufficient solubility for an injection formulation. One of the main strategies used to affect physical performance of a compound and one that is often employed by pharmaceutical scientists is the practice of salt selection (23). At least half of compounds in marketed products are in the form of a salt for one reason or another.

This fact alone speaks to the versatility of the salt selection approach. Salt forms of a pharmaceutical can have many benefits, such as improved stability characteristics, optimal bioavailability and aqueous solubility for an injectable formulation. Salts, like all other crystalline forms, are subject to polymorphism and solvate formation, thus requiring the same form identification studies as are needed for a neutral compound.

A remarkable example of co-optimization of properties is indinavir (HIV protease inhibitor), which is marketed as the sulfate salt ethanol solvate (24,25) The crystalline free base has variable oral bioavailability in dogs (26,27) and humans (28). While acidic solutions of the base compound showed good oral pharmacokinetics, the stability of the drug in acidic solution is not consistent with a product (26). Therefore, the discovery of the salt form ensured both shelf stability and robust bioavailability performance. The salt selection strategy is limited in two ways.

First, salt formation relies on the presence of one or more ionizable functional groups in the molecule; many drugs and development compounds lack this feature.

Second, our ability to predict a priori whether a given compound will form a crystalline salt (or salts) is non-existent. The ability to actively identify crystalline salt forms has been confined to manual empirical evaluation using multiple salt formers for a given acid or base. Recently advances have been made in the area of high-throughput salt selection and crystal engineering strategies associated with salt formation (14,29-32).

In one case, we have advocated the simultaneous assessment of polymorphism as a way to help rank the developability of different crystalline salts (14). While salt forms will continue to have a prominent place in pharmaceutical science, the need for enhanced productivity dictates that every advantage must be sought to aid the design of an appropriate crystalline form of an active molecule.

Specifically, the ability to design scaffolds into crystalline forms will enhance our capacity to convert interesting molecules into effective drugs. Crystal engineering offers some additional tools in this regard.

CASE STUDY FORM A ONLY US8084605

Figure imgf000073_0001TRELAGLIPTIN SUCCINATE

Form A may be prepared by crystallization from the various solvents and under the various crystallization conditions used during the polymorph screen (e.g., fast and slow evaporation, cooling of saturated solutions, slurries, and solvent/antisolvent additions). Tables B and C of Example 3 summarize the procedures by which Form A was prepared.

For example, Form A was obtained by room temperature slurry of an excess amount of Compound I in acetone, acetonitrile, dichloromethane, 1,4-dioxane, diethyl ether, hexane, methanol, isopropanol, water, ethylacetate, tetrahydrofuran, toluene, or other like solvents on a rotating wheel for approximately 5 or 7 days.

The solids were collected by vacuum filtration, and air dried in the hood. Also, Form A was precipitated from a methanol solution of Compound I by slow evaporation (SE). Form A was characterized by XRPD, TGA, hot stage microscopy, IR, Raman spectroscopy, solution 1H-NMR, and solid state 13C-NMR. Figure 1 shows a characteristic XRPD spectrum (CuKa, λ=1.5418A) of Form A. The XRPD pattern confirmed that Form A was crystalline. Major X-Ray diffraction lines expressed in °2Θ and their relative intensities are summarized in Table 1. Table 1. Characteristic XRPD Peaks (CuKa) of Form A

Figure imgf000018_0001 Figure imgf000019_0001

The above set of XRPD peak positions or a subset thereof can be used to identify Form A. One subset comprises peaks at about 11.31, 11.91, 12.86, 14.54, 15.81, 16.83, 17.59, 19.26, 19.52, 21.04, 22.32, 26.63, and 29.87 °2Θ. Another subset comprises peaks at about 11.31, 11.91, 19.26, 21.04, and 22.32 °2Θ; the peaks of this subset show no shoulder peaks or peak split greater than 0.2 °2Θ. Another subset comprises peaks at about 11.31, 11.91 and 22.32 °2Θ. Figure 2 is a TGA thermogram of Form A. TGA analysis showed that Form A exhibited insignificant weight loss when heated from 25 0C to 165 0C; this result is indicative that Form A was an anhydrous solid. Figure 3 shows a characteristic DSC thermogram of Form A. DSC analysis showed a single endothermic event occurred at approximately 195 0C (peak maximum). This endothermic event was confirmed by hot stage microscopy which showed the melting of Form A, which onset around 177 0C and the melting point estimated to be at approximately 184 0C.

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US8084605

Figure 4 (A-D) shows a characteristic FT-IR spectrum of Form A. The major bands expressed in reciprocal wavelengths (wavenumber in cm”1) are positioned at about 3815, 3736, 3675, 3460, 3402, 3141, 3098, 3068, 3049, 2953, 2934, 2854, 2760, 2625, 2536, 2481, 2266, 2225, 2176, 1990, 1890, 1699, 1657, 1638, 1626, 1609, 1586, 1553, 1517, 1492, 1478, 1450, 1419, 1409, 1380, 1351, 1327, 1289, 1271, 1236, 1206, 1180, 1158, 1115, 1087, 1085, 1064, 1037, 1027, 971, 960, 951, 926, 902, 886, 870, 831, 820, 806, 780, 760, 740, 728, 701, 685, 668, 637, 608, 594, 567, 558, and 516 cm”1 (values rounded to the nearest whole number). This unique set of IR absorption bands or a subset thereof can be used to identify Form A.

One such subset comprises absorption bands at about 3141, 3098, 3068, 3049, 2953, 2934, 2854, 2266, 2225, 1699, 1657, 1609, 1586, 1553, 1517, 1492, 1478, 1450, 1380, 1351, 1327, 1236, 1206, 1115, 1063, 902, 886, 870, 820, 780, 760, 685, 608, 594, and 516 cm 1. Another subset comprises absorption bands at about 3141, 2953, 2934, 2854, 2266, 2225, 1699, 1657, 1450, 1206, 886, 760, 685, 594, and 516 cm 1. Yet another subset comprises absorption bands at about 3141, 2953, 2934, 2266, 1699, 1657, 1450, and 1206 cm 1.

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Aprepitant case study FTIR.. READING MATERIAL http://alpha.chem.umb.edu/chemistry/ch361/spring%2005/ftir%20polymorph.pdf

Figure 5 (A-D) shows a characteristic Raman spectrum of Form A. The major Raman bands expressed in reciprocal wavelengths (wavenumber in cm”1) are positioned at about 3100, 3068, 3049, 2977, 2954, 2935, 2875, 2855, 2787, 2263, 2225, 2174, 1698, 1659, 1626, 1607, 1586, 1492, 1478, 1451, 1439, 1409, 1400, 1382, 1351, 1328, 1290, 1281, 1271, 1237, 1223, 1213, 1180, 1155, 1134, 1115, 1084, 1063, 1035, 971, 952, 926901, 868, 805, 780, 759, 740, 727, 701, 686, 669, 609, 594, 566, 558, 516, 487, 479, 433, 418, 409, 294, 274, 241, 218, 191 and 138 cm”1 (values rounded to the nearest whole number). This unique set of Raman bands or a subset thereof may be used to identify Form A.

One such subset comprises Raman bands at about 2954, 2935, 2225, 1698, 1659, and 1607 cm”1. Another subset comprises Raman bands at about 3068, 2954, 2935, 2225, 1698, 1659, 1607, 1586, 1223, 1180, 901, 780, 759, 669, and 516 cm”1. Yet another subset comprises Raman bands at about 3100, 3068, 2225, 1698, 1659, 1607, 1586, 1351, 1237, 1223, 1180, 1155, 1134, 1115, 1063, 952, 926, 901, 868, 805, 780, 759, 740, 669, 609, and 516 cm”1.

Form A was further characterized by solution 1H NMR and solid-state 13carbon NMR. The spectra are reported in Figures 6 and 7, respectively. Chemical assignments were not performed; however, the spectra are consistent with the known chemical structure of Compound I. US8084605

Figure imgf000073_0001 Example 11. Characterization of Form A Material prepared by the procedure of Example 1 was designated as Form A. The material was characterized by XRPD, TGA, DSC, hot stage microscopy, FT-IR, FT- Raman, 1H NMR, and 13C NMR. The analyses were conducted according to the procedures outlined in Section B of Example 3.

The characteristic spectra and thermograms for Form A are reported in Figures 1-7. The characterization data are summarized in Table D. Table D. Characterization Data of Form A of Compound I US8084605

Figure imgf000064_0001

Amorphous solid dispersion screening

Using the amorphous form of a drug substance offers several advantages with respect to dissolution rate and solubility of the substance. However, reduced chemical stability, increased hygroscopicity and, most important, physical instability are the major drawbacks of using the amorphous phase in the final drug product. These drawbacks can be overcome by stabilizing the amorphous phase of the API in a polymer matrix, e.q. an amorphous solid dispersion. Amorphous phases dissolve more rapidly than crystalline forms, and can significantly increase bioavailability of poorly water soluble drugs substances. However, the use of amorphous materials requires confidence that crystallization will not occur during the product lifespan. For a material that has never been obtained in a crystalline form, focus should be put on attempting to crystallize it. Crystallics has extensive experience of obtaining crystalline phases from amorphous materials.

Dispersions of a drug substance onto a polymeric matrix has received increased attention in recent years. A successful dispersion results in an amorphous solid material and will show improved dissolution rates and higher apparent solubility characteristics, as well as, sufficient resistance to chemical degradation and should be physically stable e.q. sufficient high glass transition temperature avoiding crystallization of the API.

A variety of factors contribute to the formation of a suitable Amorphous Solid Dispersion (ASD), including the nature of the polymer, the drug polymer ratio, the impact of surfactants and the solvent used in the process. Crystallics has developed high-throughput solid dispersion screening technology in order to find the optimal combination of these factors.

Example 10. Preparation of Amorphous Form US8084605

A sample of Compound I (40 mg) was dissolved in 1000 μl of water. The solution was filtered through a 0.2 μm nylon filter into a clean vial then frozen in a dry ice/acetone bath. The vials were covered with a Kimwipe then placed on a lyophilizer overnight. The resulting solids yielded Amorphous Form. 8. Amorphous Form The Amorphous Form of Compound I was prepared by lyophilization of an aqueous solution of Compound I (Example 10). The residue material was characterized by XRPD and the resulting XRPD spectrum displayed in Figure 26. The XRPD spectrum shows a broad halo with no specific peaks present, which confirms that the material is amorphous. The material was further characterized by TGA, DSC, hot stage microscopy, and moisture sorption analysis.

TGA analysis (Figure 27) showed a 1.8% weight loss from 25 0C to 95 0C, which was likely due to loss of residual solvent.

DSC analysis (Figure 28) showed a slightly concave baseline up to an exotherm at 130 0C (recrystallization), followed by an endotherm at 194 0C, which results from the melting of Form A. Hot stage microscopy confirmed these recrystallization and melting events (micrographs not included). An approximate glass transition was observed (Figure29) at an onset temperature of 82 0

C. 

Moisture sorption/desorption data (Figure 30 and Example 25) showed a 1.0% weight loss on equilibration at 5% relative humidity. Approximately 8% of weight was gained up to 65% relative humidity. Approximately 7% of weight was lost at 75% relative humidity. This is likely due to the recrystallization of the amorphous material to a crystalline solid. A 4.4% weight gain was observed on sorption from 75% to 95% relative humidity. Approximately 4.7% weight was lost on desorption from 95% to 5% relative humidity.

The solid material remaining after the moisture sorption analysis was determined to be Form A by XRPD (Figure 31). Table H. Characterization Data of Amorphous Form US8084605

Figure imgf000068_0001

T=temperature, RH=relative humidity, MB = moisture sorption/desorption analysis Example 19: Relative Humidity Stressing Experiments

 Moisture Sorption/Desorption Study of Amorphous Form.
Mositure sorption and desorption study was conducted on a sample of Amorphous Form. The sample was prepared by lyophilolization of a solution of Compound I in water (Example 3, section A.9). The mositure sorption and desorption study was conducted according to the procedures outlined in Example 3, section B.10. The data collected is plotted in Figure 29 and summarized in Table N .Table N. Moisture Sorption/Desorption of Amorphous Form
Figure imgf000072_0001

Table B. Crystallization Experiments of Compound I from Solvents

Figure imgf000059_0001
Figure imgf000060_0001
Figure imgf000061_0001
Figure imgf000062_0001

a) FE = fast evaporation; SE = slow evaporation; RT = room temperature; SC = slow cool; CC = crash cool, MB = moisture sorption/desorption analysis b) qty = quantity; PO = preferred orientation Table C. Crystallization Experiments of Compound I in Various Solvent/Antisolvent

Figure imgf000062_0002

a precipitated by evaporation of solvent Table A. Approximate Solubilities of Compound I US8084605

Figure imgf000052_0001
Figure imgf000053_0001

a) Approximate solubilities are calculated based on the total solvent used to give a solution; actual solubilities may be greater because of the volume of the solvent portions utilized or a slow rate of dissolution. Solubilities are reported to the nearest mg/mL.

Example 3.

Polymorph Screen Compound I as prepared by the method described in Example 1 was used as the starting material for the polymorph screen. Solvents and other reagents were of ACS or HPLC grade and were used as received. A. Sample Generation. Solids for form identification were prepared via the following methods from Compound I.

1. Fast Evaporation (FE) A solution of Compound I was prepared in test solvents. The sample was placed in the hood, uncovered, to evaporate under ambient conditions. The solids were analyzed by XRPD for form identification.

2. Slow Evaporation (SE) A solution of Compound I was prepared in test solvents. The sample was placed in the hood, covered with foil rendered with pinholes, to evaporate under ambient conditions. The solids were analyzed by XRPD for form identification.

3. Room Temperature (RT) Slurries An excess amount of Compound I was slurried in test solvent on a rotating wheel for approximately 5 or 7 days. The solids were typically collected by vacuum filtration, air dried in the hood, and analyzed by XRPD for form identification.

4. Elevated Temperature Slurries Excess Compound I was slurried in test solvents at 47 0C on a shaker block for approximately 5 days. The solids were collected by vacuum filtering, dried in the hood, and then analyzed by XRPD for form identification.

5. Slow Cooling Crystallization (SC)

A saturated or near saturated solution of Compound I was prepared at elevated temperature. The samples were filtered through warmed 0.2 μm filters into warmed vials. The heat source was turned off and the samples slowly cooled to ambient temperature. If precipitation did not occur within a day the samples were placed in the refrigerator. The samples were transferred to a freezer if precipitation did not occur within several days. The solids were collected by decanting the solvent or vacuum filtration, dried in the hood and analyzed by XRPD for form identification.

6. Crash Cooling Crystallization (CC) A saturated or near saturated solution of Compound I was prepared at elevated temperature. The samples were filtered through warmed 0.2 μm filters into warmed vials then rapidly cooled in an acetone/dry ice or ice bath. If precipitation did not occur after several minutes the samples were placed in the refrigerator or freezer. Solids were collected by decanting solvent or vacuum filtration, dried in the hood, and then analyzed by XRPD. Samples that did not precipitate under subambient conditions after several days were evaporated in the hood and analyzed by XRPD for form identification.

7. Solvent/Antisolvent Crystallization (S/AS) A solution of Compound I was prepared in test solvent. A miscible antisolvent was added with a disposable pipette. Precipitate was collected by vacuum filtration or decanting solvent. The samples were stored under subambient conditions if precipitation did not occur. If solids were not observed after several days the samples were evaporated in the hood. Collected solids were analyzed by XRPD for form identification.

8. Relative Humidity (RH) Stressing Experiments Samples of Compound I were placed uncovered in approximately 58%, 88%, and 97% relative humidity jars. The samples were stored in the jars for approximately 8 days. The solids were collected and analyzed by XRPD for form identification.

9. Lyophilization Compound I was dissolved in water in a glass vial. The solution was frozen by swirling the vial in an acetone/dry ice bath. The frozen sample was placed on the lyophilizer until all of the frozen solvent was removed. The solids were collected and analyzed by XRPD for form identification.

10. Grinding Experiments Aliquots of Compound I were ground manually with a mortar and pestle as a dry solid and a wet paste in water. The samples were ground for approximately three minutes. The solids were collected and analyzed by XRPD for form identification.

11. Dehydration Experiments Hydrated samples of Compound I were dehydrated at ambient conditions (2 days) and in an ambient temperature vacuum oven (1 day). The solids were collected and analyzed by XRPD for form identification.

12. Vapor Stress Experiments Amorphous Compound I was placed in acetone, ethanol, and water vapor chambers for up to eight days. The solids were collected and analyzed by XRPD for form identification.

STABILITY STUDY Stability studies are commonly performed for new drug entities with chemical stability and impurity formation being investigated. It is also important to monitor the physical stability under these same conditions to anticipate any form changes that may occur. As an example, many hydrates will dehydrate to a lower hydrate or anhydrous form at elevated temperatures. Anhydrous materials can also undergo form transformations to other anhydrous forms upon heating.

These types of changes can be monitored using heating studies in an oven with subsequent XRPD analysis or in-situ variable temperature XRPD can be used to look for changes. In other cases, anhydrates will convert to hydrates or the API in an amorphous solid dispersion may crystallize under elevated relative humidity (RH) conditions.

Equilibration in RH chambers with subsequent analysis by XRPD or in-situ variable RH XRPD experiments can be used to readily identify these form changes. Once the effect of temperature and RH on form changes is understood, this can be factored into other processes such as drying, formulation, storage, and packaging B. Sample Characterization. The following analytical techniques and combination thereof were used determine the physical properties of the solid phases prepared.

1. X-Ray Powder Diffraction (XRPD)

XRPD is commonly used as the initial method of analysis for form screens. For polymorph, salt, and co-crystal screens XRPD is used to determine if a new form has been produced by comparing the powder pattern to all known forms of the API and the counterion/guest. If a new form is found by XRPD, additional characterization by other methods is in order. For amorphous solid dispersion screens, XRPD is used to confirm a lack of crystallinity indicated by an amorphous halo in the powder pattern.

The halos will move depending on the concentration and interactions of the API and polymer. Computational methods have also been used with XRPD data to establish miscibility of amorphous solid dispersions X-ray powder diffraction is a front line technique in solid form screening and selection based on its ability to give a fingerprint of the solid-state structure of a pharmaceutical material. Understanding the solid forms of a pharmaceutical compound provides a road map to help direct a variety of development activities ranging from crystallization, formulation, packaging, storage, and performance.

Different screening and selection strategies are warranted in early and late development because different information is needed at the various stages. Solid form selection and formulation approaches need to be investigated together and tailored to the situation. It is important to include solid form selection and possible changes in form as part of the risk management strategy throughout the drug development process.

X-ray powder diffraction (XRPD) analyses were performed using an Inel XRG- 3000 diffractometer equipped with a CPS (Curved Position Sensitive) detector with a 2Θ (2Θ) range of 120°. Real time data were collected using Cu-Ka radiation starting at approximately 4 °2Θ at a resolution of 0.03 °2Θ. The tube voltage and amperage were set to 40 kV and 30 mA, respectively. The pattern is displayed from 2.5 to 40 °2Θ. Samples were prepared for analysis by packing them into thin- walled glass capillaries. Each capillary was mounted onto a goniometer head that is motorized to permit spinning of the capillary during data acquisition. The samples were analyzed for approximately 5 minutes.

Instrument calibration was performed using a silicon reference standard. Peak picking was performed using the automatic peak picking in the Shimadzu XRD-6000 Basic Process version 2.6. The files were converted to Shimadzu format before performing the peak picking analysis. Default parameters were used to select the peaks.

2. Thermogravimetric Analysis (TGA)

Thermogravimetric (TG) analyses were performed using a TA Instruments 2950 thermogravimetric analyzer. Each sample was placed in an aluminum sample pan and inserted into the TG furnace. The furnace was first equilibrated at 25 0C, then heated under nitrogen at a rate of 10 °C/min, up to a final temperature of 350 0C. Nickel and Alumel™ were used as the calibration standards.

3. Differential Scanning Calorimetry (DSC)

Differential scanning calorimetry (DSC) was performed using a TA Instruments differential scanning calorimeter 2920. The sample was placed into an aluminum DSC pan, and the weight accurately recorded. The pan was covered with a lid and then crimped. The sample cell was equilibrated at 25 0C and heated under a nitrogen purge at a rate of 10 °C/min, up to a final temperature of 350 0C. Indium metal was used as the calibration standard. Reported temperatures are at the transition maxima. For studies of the glass transition temperature (Tg) of the amorphous material, the sample cell was equilibrated at ambient temperature, then heated under nitrogen at a rate of 20 °C/min, up to 100 0C. The sample cell was then allowed to cool and equilibrate at -20 0C. It was again heated at a rate of 20 °C/min up to 100 0C and then cooled and equilibrated at -20 0C. The sample cell was then heated at 20 °C/min up to a final temperature of 350 0C. The Tg is reported from the onset point of the transition.

4. Hot Stage Microscopy.

Hot stage microscopy was performed using a Linkam hot stage (model FTIR 600) mounted on a Leica DM LP microscope. The samples were prepared between two cover glasses and observed using a 20χ objective with crossed polarizers and first order compensator. Each sample was visually observed as the stage was heated. Images were captured using a SPOT Insight™ color digital camera with SPOT Software v. 3.5.8. The hot stage was calibrated using USP melting point standards.

5. Thermogravimetric-Infrared (TG-IR)

Thermogravimetric infrared (TG-IR) analyses were acquired on a TA Instruments thermogravimetric (TG) analyzer model 2050 interfaced to a Magna 560® Fourier transform infrared (FT-IR) spectrophotometer (Thermo Nicolet) equipped with an Ever-Glo mid/far IR source, a potassium bromide (KBr) beamsplitter, and a deuterated triglycine sulfate (DTGS) detector. The TG instrument was operated under a flow of helium at 90 and 10 cc/min for the purge and balance, respectively. Each sample was placed in a platinum sample pan, inserted into the TG furnace, accurately weighed by the instrument, and the furnace was heated from ambient temperature to 250 0C at a rate of 20 °C/min.

The TG instrument was started first, immediately followed by the FT-IR instrument. Each IR spectrum represents 32 co-added scans collected at a spectral resolution of 4 cm“1. A background scan was collected before the beginning of the experiment. Wavelength calibration was performed using polystyrene. The TG calibration standards were nickel and Alumel™. Volatiles were identified from a search of the High Resolution Nicolet TGA Vapor Phase spectral library.

6. Fourier Transform Infrared Spectroscopy (FT-IR)

Infrared spectra were acquired on a Magna-IR 560® or 860® Fourier transform infrared (FT-IR) spectrophotometer (Thermo Nicolet) equipped with an Ever-Glo mid/far IR source, an extended range potassium bromide (KBr) beamsplitter, and a deuterated triglycine sulfate (DTGS) detector. A diffuse reflectance accessory (the Collector™, Thermo Spectra-Tech) was used for sampling. Each spectrum represents 256 co-added scans collected at a spectral resolution of 4 cm“1. Sample preparation consisted of physically mixing the sample with KBr and placing the sample into a 13 -mm diameter cup. A background data set was acquired on a sample of KBr. A Log 1/R (R = reflectance) spectrum was acquired by taking a ratio of these two data sets against each other. Wavelength calibration was performed using polystyrene. Automatic peak picking was performed using Omnic version 7.2.

7. Fourier Transform Raman Spectroscopy (FT-Raman)

FT-Raman spectra were acquired on a Raman accessory module interfaced to a Magna 860® Fourier transform infrared (FT-IR) spectrophotometer (Thermo Nicolet). This module uses an excitation wavelength of 1064 nm and an indium gallium arsenide (InGaAs) detector. Approximately 0.5 W of Nd)YVO4 laser power was used to irradiate the sample. The samples were prepared for analysis by placing the material in a glass tube and positioning the tube in a gold-coated tube holder in the accessory. A total of 256 sample scans were collected from at a spectral resolution of 4 cm“1, using Happ-Genzel apodization. Wavelength calibration was performed using sulfur and cyclohexane. Automatic peak picking was performed using Omnic version 7.2.

8. Solid State Nuclear Magnetic Resonance Spectroscopy (13C-NMR)

The solid-state 13C cross polarization magic angle spinning (CP/MAS) NMR spectrum was acquired at ambient temperature on a Varian UN1TYINOVA-400 spectrometer (Larmor frequencies: 13C = 100.542 MHz, 1H = 399.799 MHz). The sample was packed into a 4 mm PENCIL type zirconia rotor and rotated at 12 kHz at the magic angle. The spectrum was acquired with phase modulated (SPINAL-64) high power 1H decoupling during the acquisition time using a 1H pulse width of 2.2 μs (90°), a ramped amplitude cross polarization contact time of 5 ms, a 30 ms acquisition time, a 10 second delay between scans, a spectral width of 45 kHz with 2700 data points, and 100 co-added scans. The free induction decay (FID) was processed using Varian VNMR 6.1C software with 32768 points and an exponential line broadening factor of 10 Hz to improve the signal-to- noise ratio. The first three data points of the FID were back predicted using the VNMR linear prediction algorithm to produce a flat baseline. The chemical shifts of the spectral peaks were externally referenced to the carbonyl carbon resonance of glycine at 176.5 ppm. 9. Solution Nuclear Magnetic Resonance Spectroscopy (1H-NMR) The solution 1H NMR spectrum was acquired at ambient temperature with a

Figure imgf000058_0001

spectrometer at a 1H Larmor frequency of 399.803 MHz. The sample was dissolved in methanol. The spectrum was acquired with a 1H pulse width of 8.4 μs, a 2.50 second acquisition time, a 5 second delay between scans, a spectral width of 6400 Hz with 32000 data points, and 40 co-added scans. The free induction decay (FID) was processed using Varian VNMR 6.1C software with 65536 points and an exponential line broadening factor of 0.2 Hz to improve the signal-to-noise ratio. The spectrum was referenced to internal tetramethylsilane (TMS) at 0.0 ppm. 10.

Moisture Sorption/Desorption Analysis Moisture sorption/desorption data were collected on a VTI SGA-100 Vapor Sorption Analyzer. Sorption and desorption data were collected over a range of 5% to 95% relative humidity (RH) at 10% RH intervals under a nitrogen purge. Samples were not dried prior to analysis. Equilibrium criteria used for analysis were less than 0.0100% weight change in 5 minutes, with a maximum equilibration time of 3 hours if the weight criterion was not met. Data were not corrected for the initial moisture content of the samples. NaCl and PVP were used as calibration standards

Does solid form matter? 

Sometimes the properties of two solid forms of a drug are quite similar. In other cases, the physical and chemical properties can vary dramatically and have great impact on pharmacokinetics, ease of manufacturing, and dosage form stability. Properties that can differ among solid forms of a substance include color, solubility, crystal shape, water sorption and desorption properties, particle size, hardness, drying characteristics, flow and filterability, compressibility, and density.

Different solid forms can have different melting points, spectral properties, and thermodynamic stability. In a drug substance, these variations in properties can lead to differences in dissolution rate, oral absorption, bioavailability, levels of gastric irritation, toxicology results, and clinical trial results. Ultimately both safety and efficacy are impacted by properties that vary among different solid forms. Stability presents a special concern, since it’s easy to inadvertently generate the wrong form at any point in the development process.

Because energy differences between forms are usually relatively small, form interconversion is common and can occur during routine API manufacturing operations and during drug product formulation, storage, and use. The stakes are high. Encountering a new solid form during late stages of development can delay filing. A new form appearing in drug product can cause product withdrawal.  

When should a search for solid forms begin?

The key to speed in the drug development process is to do it right the first time. For solid pharmaceuticals, that means:

  • identify the optimum solid form early in drug development
  • make the same form for clinical material and commercial API
  • develop a crystallization process that assures control of solid form
  • produce a drug product with solid form stability through expiration

scientists strongly recommend that investigation of possible solid forms of a new chemical entity be carried out as early in the development process as drug supply will allow. The best approach has three stages. The first stage, more relevant to some development processes than to others, is a milligram-scale abbreviated screen on efficacious compounds prior to final IND candidate selection. This early information can be used to guide selection of salts and solid forms for scale-up and toxicology studies. The second stage is full polymorph screening and selection of optimum solid form. This stage is important to all development processes and should certainly occur before the first GMP material is produced. In the case of ionic drugs, various salts should be prepared and screened for polymorphs and hydrates. The third stage, an exhaustive screen carried out before drug launch, is an effort to find and patent all of the forms of a high-potential drug. Staging the screening in this way optimizes the balance among the factors of early knowledge of options, probability of commercial success, and judicious investment of R&D money.

Delay in understanding solid form issues results in problems like different batches of clinical material having different solid forms. Another common and preventable dilemma arises when clinical trials are carried out with one form while commercial production generates another. In this case, bridging studies are required to demonstrate to regulatory agencies that the clinicals are relevant. ICH guidelines require a search for solid forms, comparison of properties that might affect product efficacy, and, if appropriate, setting of solid form specifications.

How is solid form controlled in API manufacture? 

It is important to control solid form during API synthesis in order to demonstrate complete process control to regulatory agencies. Different solid forms can have different solubilities and can affect recovery of API. Purification efficiencies can vary due to differential exclusion of impurities. Filtration and transfer characteristics often differ between forms. Ease of drying can vary due to different abilities to bind solvent and water in the crystal lattice. A prevalent but incorrect belief is that solid form is determined primarily by choice of crystallization solvent. In fact, it is well established that parameters like temperature, supersaturation level, rate of concentration or cooling, seeding, and ripening can have an overriding effect. These variables must be controlled to ensure consistency of solid form in API.

Can solid form problems arise in drug products, too? 

The potential for solid form variation does not end at API production. Solid form issues remain through formulation, manufacture, storage, and use of drug product. It is common to observe form transformation during standard manufacturing operations like wet granulation and milling. Excipient interactions and compaction can induce form changes. Changes can occur in the final dosage form over time. Suspensions, including those in transdermal patches, are particularly vulnerable because they provide a low-energy pathway (dissolution/recrystallization) for form interconversion. Lyophile cakes are normally amorphous, but can crystallize on storage leading to difficulty in reconstitution. Even products containing drug in solution, such as filled gel caps, can be affected if the solution is or becomes supersaturated with respect to one of the possible solid forms of the drug.

How can you tell when you have a solid form problem? 

Whenever there is a specification failure in drug product or drug substance, solid form changes should be considered in the search for causes. Particularly symptomatic is failure to meet melting point or dissolution specifications. Changes in humidity, crystallization conditions, or crystallization solvent can produce unwanted forms. Solvents known to readily produce solvates include water, alcohols, chlorinated hydrocarbons, cyclic ethers, ketones, nitriles, and amides. Changes in the appearance of gel caps or cracking of tablet coatings can indicate solid form problems. Various solid-state analytical techniques can be used to identify solid form in API. Some techniques can even determine solid form of API in intact final dosage form. Among the most useful techniques for solid-state characterization are melting point, DSC, TGA, hot stage and optical microscopy, solid-state NMR, IR and Raman spectroscopy, and X-ray powder diffraction.

Is there any good news about polymorphism? 

Polymorphism presents opportunities as well as challenges. Investigation of the properties of different forms of a commercial drug can lead to new products with improved onset time, greater bioavailability, sustained release properties, or other therapeutic enhancements. New forms can bring improvements in manufacturing costs or API purity. These improvements are patentable and can provide a competitive advantage. An underutilized potential of polymorphism is to solve formulation problems that cause the abandonment of potentially useful drugs in which much investment has already been made.

SOLUBILITY

Solubility is an important parameter for new molecules especially with the emergence of many poorly soluble compounds in the drug discovery and development pipeline. Polymorphic forms can exhibit solubility differences that vary within a factor of 1-5, amorphous solid dispersions show an improvement one or two orders of magnitude higher, and salts and co-crystals fall between these extremes . A comparison of solubility values of pure forms will provide important information when deciding on a solid form or dosage form. X-ray powder diffraction will allow identification of pure forms for these types of measurements.

However, form changes during solubility and dissolution experiments are also possible and need to be investigated. Solids remaining at the end of solubility and dissolution experiments should always be analyzed initially by XRPD to determine if a form transformation has occurred under these conditions. If a form change has occurred, XRPD patterns can be compared to known forms (polymorphs, hydrates, salts, free acid/base) in order to identify the solids remaining. If a pattern is obtained that does not correspond to known forms, complementary methods will be needed to determine properties such as hydration state or a change in stoichiometry as would be observed from breaking a salt and forming the free acid/base or the formation of salts in buffered solutions.

FORMULATION

Formulators are charged with the responsibility to formulate a product which is physically and chemically stable, manufacturable, and bioavailable. Most drugs exhibit structural polymorphism, and it is preferable to develop the most thermodynamically stable polymorph of the drug to assure reproducible bioavailability of the product over its shelf life under a variety of real-world storage conditions. There are occasional situations in which the development of a metastable crystalline or amorphous form is justified because a medical benefit is achieved. Such situations include those in which a faster dissolution rate or higher concentration are desired, in order to achieve rapid absorption and efficacy, or to achieve acceptable systemic exposure for a low-solubility drug.

Another such situation is one in which the drug remains amorphous despite extensive efforts to crystallize it. If there is no particular medical benefit, there is less justification for accepting the risks of intentional development of a metastable crystalline or amorphous form. Whether or not there is medical benefit, the risks associated with development of a metastable form must be mitigated by laboratory work which provides assurance that (a) the largest possible form change will have no substantive effect on product quality or bioavailability, and/or (b) a change will not occur under all reasonable real-world storage conditions, and/or (c) analytical methodology and sampling procedures are in place which assure that a problem will be detected before dosage forms which have compromised quality or bioavailability can reach patients.

Crystal engineering and co-crystals

Crystal engineering is generally considered to be the design and growth of crystalline molecular solids with the aim of impacting material properties. A principal tool is the hydrogen bond, which is responsible for the majority of directed intermolecular interactions in molecular solids. Co-crystals are multi-component crystals based on hydrogen bonding interactions without the transfer of hydrogen ions to form salts – this is an important feature, since Brønsted acid-base chemistry is not a requirement for the formation of a co-crystal.

Co-crystallization is a manifestation of directed self-assembly of different components. Co-crystals have been described of various organic substances over the years (33,34) and given various names, such as addition compounds (35,36) molecular complexes (37,38) and heteromolecular co-crystals (39). Regardless of naming convention, the essential meaning is that of a multi-component crystal where no covalent chemical modification of the constituents occurs as a result of the crystal formation. Pharmaceuticals co-crystals have only recently been discussed as useful materials for drug products.  

Pharmaceutical co-crystals

Pharmaceutical co-crystals can be defined as crystalline materials comprised of an active pharmaceutical ingredient (API) and one or more unique co-crystal formers, which are solids at room temperature. Co-crystals can be constructed through several types of interaction, including hydrogen bonding, p-stacking, and van der Waals forces. Solvates and hydrates of the API are not considered to be co-crystals by this definition. However, co-crystals may include one or more solvent/water molecules in the crystal lattice. An example of putative design, a construction and preparation process is shown in Figure 2 for the 5-fluororuracil:urea 1:1 co-crystal(40).

This real example neatly illustrates the opportunity and challenge that exists currently with designing pharmaceutical co-crystals. Firstly, the ‘design’ is challenging because we have no ability to predict the exact crystal structure that may result from a crystallization attempt. By analogy to the challenge of deriving protein structure from first principles, the primary sequence (chemical structure in our case) is known and elements of secondary structure (the 2-D tape construction in Figure 2) are somewhat discernible from primary information. Prediction of the actual 3-D folded conformation (tertiary structure or obtained by self-assembly) is not possible. In other words, while we currently have the ability to project which things associate in what approximate manner on the secondary level, crystal structure prediction is essentially an intractable proposition.

By extension, and just as the exact function of a protein and quantitative parameters of activity are not predictable from primary and secondary structure, the prediction of crystal properties is not possible in the absence of structural information and measurements. There is early evidence that practitioners were aware that apparent co-crystallization of drugs could lead to useful preparations (41). In fact, a ‘chemical compound’ composed of sulfathiazole and proflavin dubbed flavazole was used to treat bacterial infection during the Second World War (42).

The case of flavazole reveals insight into how two different molecules might interact in a putative co-crystal:“… flavazole is definitely a chemical compound containing equimolar proportions of sulphathiazole and proflavin base. It is believed that combination occurs through the acidic sulphonamide group (SO2NH) of the sulphathiazole and the basic centres of the proflavin. Perhaps the most realistic expression of the formula would be to place proflavin and sulphathiazole side by side with a comma between them.” (42)  In the second half of the 20th century, interest in co-crystals evolved into the directed study of intermolecular interactions in crystalline solids (43-45). The technical development of routine single-crystal structure determination led to a watershed of data, now largely accessible through the Cambridge Structural Database (CSD) (46,47).

The structural data have become useful for understanding the intermolecular interactions in co-crystals in atomic level detail (48). Using insight gained from analysis of the CSD and directed experimentation, scientists attempt design of co-crystals with specific properties, such as color or non-linear optical response, by selecting starting components with appropriate molecular properties likely to exhibit specific intermolecular interactions in a crystal (49-52).

However, even when chemically compatible functional groups are present it is not possible to accurately predict if a co-crystal, a eutectic mixture or simply a physical mixture will result from any given experiment. As a result of these complexities, attention has been directed at the identification and characterization of intermolecular packing motifs with the goal of developing principles for co-crystal materials (53).

Figure 2.  Steps involved in crystal engineering of a pharmaceutical phase, exemplified by the real example of co-crystallization of 5-fluorouracil and urea. Scientists in India have reported a rare example of synthon polymorphism in co-crystals of 4,4′-bipyridine and 4-hydroxybenzoic acid.

Graphical abstract: Synthon polymorphism and pseudopolymorphism in co-crystals. The 4,4′-bipyridine–4-hydroxybenzoic acid structural landscape

Polymorphism is defined as the ability of a material to exist in more than one form or crystal structure. It has important implications for the properties of such materials; for example in pharmaceuticals, the dissolution rate of a drug can be dependent on the polymorphic form. While this is a common phenomenon in single crystals it is much less common in co-crystals, systems where the structure has at least two distinct components. Gautam Desiraju from the Indian Institute of Science, found that when 4,4′-bipyridine and 4-hydroxybenzoic acid were dissolved together in a solvent such as methanol they would co-crystallise to form two different polymorphs. They noticed that a third form, a pseudopolymorph, was also present.

PROSPECTS FOR CRYSTAL ENGINEERING AND PHARMACEUTICAL CO-CRYSTALS

At the beginning of the 21st century, the field of crystal engineering has experienced significant development. Importantly, crystal engineering principles are now being actively considered for application to pharmaceuticals to modulate the properties of these valuable materials (54).

Because the physical properties that influence the performance of pharmaceutical solids are reasonably well appreciated, there is a unique opportunity to apply crystal engineering techniques and the appropriate follow-up studies to solve real world problems, such as poor physical and chemical stability or inadequate dissolution for appropriate biopharmaceutical performance of an oral drug. As structures and series of pharmaceutical co-crystals have begun to appear, we again find that properties cannot be predicted from the structures.  Nevertheless, occasional trends have been suggested.

For example, insoluble drug compounds co-crystallized with highly water soluble complements tend to achieve kinetic solubilities in aqueous media several times greater than the pure form (55,56).

There are also more possible phases for each given active compound to consider, thus there will arguably be a greater opportunities for property enhancement. In terms of stability enhancement and solubilization, the example of the series of itraconazole co-crystals with pharmaceutically acceptable 1,4-diacids (55) suggests a strategy alternative to amorphous drug formulation. The co-crystal options presented retain the stability inherent in a crystalline state, while allowing for solubilization that significantly exceeds that of crystalline itraconazole base and rivals the performance of the engineered amorphous bead formulation (Sporanox®).

Where are we now? From recent literature it appears that knowledge gained over the past century and increasingly sophisticated screening techniques developed within the last decade are paving the way towards design of co-crystals with potentially improved pharmaceutical properties (55-58) In terms of the application to pharmaceutical systems, the field of crystal engineering is developing the retro-synthetic understanding of crystal structure using reasoning that is analogous to that applied by organic chemists.  For example, the retro-synthetic approach in covalent synthesis operates on the level of a single molecule, while the analogous effort in crystal engineering focuses on the “supermolecule”:

piracetam

The assemblies that define the crystalline arrangement of the molecules as they self-organize into the solid-state. The parallels between the development of crystal engineering and synthetic organic chemistry run still deeper. Methodologies for carrying out these crystallizations are being developed alongside the development of new robust motifs (6,53,55,57,60). The importance of the solubility and dissolution relationships of the components of a putative co-crystal is becoming a matter of significant investigation (56,60). The same can be said for the roles of additives in templating novel forms.

Mechanical milling of materials has also been documented as a means to make co-crystals, and a recent example of polymorphic forms of caffeine:glutaric acid illustrates the opportunities of this type of processing to influence crystal form (61). With an increase in the understanding of the modes of self-assembly, one can start to address the design aspect towards making pharmaceutical co-crystals.

There remain several limitations to the application of what is currently known to the design of useful materials. As mentioned earlier, it remains intractable to reliably predict crystal structure.  Multi-component crystals are well out of reach for prediction due in part to complex energetic landscapes, lack of appropriate charge density models and a large number of degrees of freedom, making computation unfeasible. Moreover, there is only a qualitative understanding of the interplay between intermolecular interactions and materials performance, especially for properties relevant to pharmaceuticals such as solubility, dissolution profile, hygroscopicity and melting point.

But the saving grace of the co-crystal approach comes in two guises: Complementarity and diversity. On the topic of complementarity, it is possible, by way of CSD database mining for instance, to identify trends of hetero-synthon occurrence in model systems. As for the diversity aspect, the space of possible co-crystal formers is large, limited only by pharmaceutical acceptability. Coupled with parameters such as stoichiometry variation and increase in the number of components (binary systems can be expanded into ternary ones, etc.), the opportunities appear vast.

THE FUTURE OF CRYSTAL ENGINEERING IN PHARMACEUTICAL SCIENCE

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READ

Novel Challenges in Crystal Engineering: Polymorphs and New 

http://www.intechopen.com/…/novel-challenges-in-crystal-engineering-polymNovel Challenges in Crystal Engineering: Polymorphs and New Crystal Forms of ActivePharmaceutical Ingredients

Where are we going?  At this point, we have only just scratched the surface of materials science-driven pharmaceutical product design. In the 21st century, practitioners of pharmaceutical chemistry need to enumerate and exploit the opportunities of crystal form design that nature affords us, and thus gain increasing ability to design the materials we need from the molecules that we seek to convert into pharmaceuticals.

Learning will be facilitated by advances in crystallization automation (6,62), microscopy-spectroscopy techniques (Raman and IR microscopy) and new techniques such as terahertz spectroscopy and AFM, along with increasingly sophisticated X-ray diffraction lab instrumentation. In addition, further enhancements in the data mining tools associated with the CSD operating on an ever increasing number of high-quality crystal structures will undoubtedly lead to new knowledge and principles of interaction.

The challenge placed before pharmaceutical scientists, now and in the future, is the following: (i) to understand the requirement of a particular compound in terms of materials structure and properties, and (ii) to creatively integrate crystal engineering within the limits of pharmaceutical acceptability of components to obtain new forms of active ingredients with desirable properties for formulation and delivery. It should become the collective mantra of medicinal chemists, process engineers and pharmaceutical scientists to “design and make the material we need.” This mantra can form the common aspiration for an industry that is in significant need of innovation and productivity enhancement.

Applications and Advantages

Applications

  • Drug companies can use this technology to protect themselves against others generating and patenting polymorphs

Advantages

  • Having more than one solid form of a drug allows optimization of drug dissolution behavior and shelf life

IP AND POLYMORPHS

In order for a new drug to enter the market, pharmaceutical companies must invest for many years in very expensive clinical trials and a lengthy regulatory approval process.Market protection plays therefore a major role in the growth of the pharmaceutical industry and Intellectual Property (IP) laws are intended to give the investors an opportunity to recover their costs. Patent filing is one way of efficiently protecting various aspects of an innovative drug.
The duration of the new drug’s market protection is, however, limited in time and once the original drug is no longer protected, legal copies (generic medicines) can be developed and marketed by competitors at more accessible prices, since the expensive basic research, as well as pre-clinical and clinical trials (at least for small molecules) are no longer necessary. Generic medicines are either identical copies of the original drug or so-called bioequivalent versions of it.
Bioequivalent means that they behave as the original drug when administered to patients. For a generic drug to be a bioequivalent its Active Pharmaceutical Ingredient (API) does not need to be the same solid form as in the original drug. A different polymorph or a pseudo-polymorph (i.e. solvate, hydrate) of the API and different excipients are acceptable variants, as long as the final generic drug product behaves as the original one.  
Solid Forms Screening
Screening of solid forms, in particular polymorphs of APIs, is therefore an essential part of pharmaceutical development and lifecycle management, not only for scientific and regulatory reasons, but also because of the key role that pharmaceutical solid forms play in the area of IP, for innovators as well as for generic companies. The knowledge generated by conducting solid form screening, in fact, can provide an innovator company the opportunity to build a strong patent portfolio around different solid forms and therefore a way to maximize returns from drug development.
This allows innovator companies to gain several years of additional protection for their product after the expiry of the basic molecule patent, since various pharmaceutical solid forms are individually patentable. In the US, for instance, innovator companies are required to identify, in the so-calledOrange Book, their patents covering different solid forms performing the same as the product described in the corresponding NDA. In return, they can benefit from a 30-months stay over a generic company which would eventually file an ANDA with aParagraph IV Certification for any of these listed patents.
 
Thus, by patenting a maximum number of possible solid forms, even if these are not further developed and used, innovator companies can more efficiently protect their own products. Such patents must obviously meet the same patentability criteria as other inventions. Conversely, a generic company can launch its own product if, after the basic molecule patent has expired, it discovers a new solid form, i.e. a form with no IP protection and suitable characteristics for product development.
In both cases, a very sensitive tool as SR-XRPD can play a key role in helping the detection and characterization of a maximum number of polymorphs.
 Accurate and direct characterization of the API polymorphic forms and detection of trace amounts has proven to be of paramount importance (e.g. Paxil®, Cefdinir) whereas poorly conducted screens and unsuccessful patenting strategies, on the other hand, can have significant negative commercial consequences (e.g. Ritonavir).
Interestingly, in the US the first ANDA approved by FDA with paragraph IV certification is entitled to 180-days marketing exclusivity. Initially granted only when theANDA applicant having filed Paragraph IV Certification could prevail in the litigation with the originator, the new FDA guidance suppresses the “successul defence”requirement and the 180-days exclusivity is decided on a case-by-case basis and can therefore be granted even if the case is settled.
While there has been much discussion by policymakers and stakeholders about the effects of “secondary patents” on the pharmaceutical industry, there is no empirical evidence on their prevalence or determinants. Characterizing the landscape of secondary patents is important in light of recent court decisions in the U.S. that may make them more difficult to obtain, and for developing countries considering restrictions on secondary patents.
It is seen the claims of the 1304 Orange Book listed patents on all new molecular entities approved in the U.S. between 1988 and 2005, and coded the patents as including chemical compound claims (claims covering the active molecule itself) and/or one of several types of secondary claims. It is seen that  distinguish between patents with any secondary claims, and those with only secondary claims and no chemical compound claims (“independent” secondary patents).
It is seen  that secondary claims are common in the pharmaceutical industry. It is seen that independent secondary patents tend to be filed and issued later than chemical compound patents, and are also more likely to be filed after the drug is approved. When present, independent formulation patents add an average of 6.5 years of patent life (95% C.I.: 5.9 to 7.3 years), independent method of use patents add 7.4 years (95% C.I.: 6.4 to 8.4 years), and independent patents on polymorphs, isomers, prodrug, ester, and/or salt claims add 6.3 years (95% C.I.: 5.3 to 7.3 years). evidence that late-filed independent secondary patents are more common for higher sales drugs
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Polymorph quantification. REF 79
SEE A SLIDESHARE PRESENTATION
The ability to detect and quantify polymorphism of pharmaceuticals is critically important in ensuring that the formulated product delivers the desired therapeutic properties because different polymorphic forms of a drug exhibit different solubilities, stabilities and bioavailabilities. The purpose of this study is to develop an effective method for quantitative analysis of a small amount of one polymorph within a binary polymorphic mixture. Sulfamerazine (SMZ), an antibacterial drug, was chosen as the model compound. The effectiveness and accuracy of powder X-ray diffraction (PXRD), Raman microscopy and differential scanning calorimetry (DSC) for the quantification of SMZ polymorphs were studied and compared.
Low heating rate in DSC allowed complete transformation from Form I to Form II to take place, resulting in a highly linear calibration curve. Our results showed that DSC and PXRD are capable in providing accurate measurement of polymorphic content in the SMZ binary mixtures while Raman is the least accurate technique for the system studied.
DSC provides a rapid and accurate method for offline quantification of SMZ polymorphs, and PXRD provides a non-destructive, non-contact analysis.A novel method of detecting very low levels of different polymorphs using high-resolution X-ray powder diffraction with a synchrotron light source has been developed by Zach-Zambon Chemicals of Italy. Key to the project has been development of software to enable appropriate data presentation.The issue of polymorphism in pharmaceuticals has attracted increasing attention over the past 20 years and is something to which development scientists and the regulatory authorities pay considerable attention.
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REFERENCES

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[26] G.Y. Kwei, L. B. Novak, L. A. Hettrick, E. R. Reiss, D. Ostovic, A. E. Loper, C. Y. Lui, R. J. Higgins, I. W. Chen, J. H. and Lin. , Rediospecific Intestinal Absorption of HIV protease inhibitor L-735,524 in beagle dogs. Pharm Res, 12:884, 1995.
[27] J. H. Lin, I.-W. Chen, K. J. Vastag, and D. Ostovic. pH-dependent oral absorption of L-735,524, a potent HIV protease inhibitor, in rats and dogs. Drug Metab Disp  23:730-735, 1995.
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[29] P J. Desrosiers. The potential of preform. Modern Drug Discovery, 7:40-43, 2004.
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[33] For example, d-glucose:sodium chloride monohydrate is described in F. v. Kobell and J. F. Prakt Chemie, 28:489, 1843.
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[37] For example see, A. Damiani, P. De Santis, E. Giglio, A. M. Liquori, R. Puliti and A. Ripamonti. The crystal structure of the 1:1 molecular complex between 1,3,7,9-tetramethyluric acid and pyrene. Acta Crystallogr,19:340-8, 1965.
[38] J. N. Van Niekerk and D. H. Saunder. The crystal structure of the molecular complex of 4,4′-dinitrobiphenyl with biphenyl. Acta Crystallogr,1:44, 1948.
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[40] 5-Fluorouracil:urea. C4H3N2O2F.CH4N2O; C2/c= 9.461(3) Å, b = 10.487(3) Å, c = 15.808(4) Å, β = 99.89(7)º; = 4; T = 100(2) K; GOF = 1.023, R2 = 0.0663; wR2 = 0.1753.
[41] C. G. Santesson. Addition Combinations.  Archiv fuer Experimentelle Pathologie und Pharmakologie, 118:313-24, 1926.
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[50] M. C. Etter and G. M. Frankenbach. Hydrogen-bond directed cocrystallization as a tool for designing acentric organic solids.  Chem Mater, 1:10-12, 1989.
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[52] J. A. R. P. Sarma and G. R. Desiraju. Crystal engineering via donor-acceptor interactions.  X-ray crystal structure and solid state reactivity of the 1:1 complex, 3,4-dimethoxycinnamic acid-2,4-dinitrocinnamic acid.  J Chem Soc, Chem Commun, :45-46, 1983.
[53] For example, C. B. Åakeroy, J. Desper and B. A. Helfrich. CrystEngComm, 6:19-24, 2004.
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[55] J. F. Remenar, S. L. Morissette, M. L. Peterson, B. Moulton, J. M. MacPhee,H. Guzmán and Ö. Almarsson. Crystal engineering of novel cocrystals of a triazole drug with 1,4-dicarboxylic acids.  J Am Chem Soc, 125:8456-8457, 2003.
[56] S. L. Childs, L. J. Chyall, J. T. Dunlap, V. N. Smolenskaya, B. C. Stahly and G. P. Stahly. Crystal Engineering Approach To Forming Cocrystals of Amine Hydrochlorides with Organic Acids. Molecular Complexes of Fluoxetine Hydrochloride with Benzoic, Succinic, and Fumaric Acids. J Am Chem Soc,126:13335-13342, 2004.
[57] S. Fleischman, L. Morales; B. Moulton, N. Rodríguez-Hornedo, R. Bailey Walsh and M. J. Zaworotko. Crystal engineering of the composition of pharmaceutical phases.Chem Commun,186, 2003.
[58] A. V. Trask, W. D. S. Motherwell and W. Jones. Solvent-drop Grinding: Green Polymorph Control of Cocrystallisation. Chem Commun, 890-891, 2004.
[59] N. Variankaval, R. Wenslow, J. Murry, R. Hartman, R. Helmy, E. Kwong, S.-D. Clas, C. Dalton and I. Santos. Preparation and Solid-State Characterization of Nonstoichiometric Cocrystals of a Phosphodiesterase-IV Inhibitor and L-Tartaric Acid.  Cryst Growth Des, 6:690-700 2006.
[60] S. J. Hehm, B. Rodriguez-Spong and N Rodriguez-Hornedo. Phase Solubility Diagrams of Cocrystal Are Explained by Solubility Product and Solution Complexation: Cryst Growth Des, 6:592-600, 2006.
[61] A. V. Trask, N. Shan, W. D. S. Motherwell, W. Jones, S. Feng, R. B. H. Tan and K. J. Carpenter. Selective Polymorph Transformation via Solvent-drop Grinding. Chem Commun,, 880-882, 2005.
[62] A. V. Trask, N. Shan, W. D. S. Motherwell, W. Jones, S. Feng, R. B. H. Tan and K. J. Carpenter. Selective Polymorph Transformation via Solvent-drop Grinding. Chem Commun,, 880-882, 2005.

63……..POLYMORPHISM AND PATENTS http://www.collegio.unibo.it/uploads/ideas/joelbernstein.pdf 64…Aprepitant case study FTIR.. READING MATERIALhttp://alpha.chem.umb.edu/chemistry/ch361/spring%2005/ftir%20polymorph.pdf 65…..READ………….An Overview of Solid Form Screening During Drug Development, http://www.icdd.com/ppxrd/10/presentations/PPXRD-10_Ann_Newman.pdf 66…..CRYSTALLIZATION..http://www.intechopen.com/books/advanced-topics-on-crystal-growth/crystallization-from-the-conformer-to-the-crystal

67International Conference on Harmonization Q6A Guideline: Specifications for New Drug Substances and Products: Chemical Substances, October 1999.

68Center for Drug Evaluation and Research Guidance: Submitting Supporting Documentation in Drug Applications for the Manufacture of Drug Substances, February 1987.

69S. Byrn, R. Pfeiffer, M. Ganey, C. Hoiberg, and G. Poochikian. Pharmaceutical solids: A strategic approach to regulatory considerations. Pharm. Res. 12:945-954 (1995). 70

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  2. L. X. Yu and G. L. Amidon GL. Analytical Solutions to Mass Transfer. In: G. L. Amidon, P. I. Lee, and E. M. Topp (eds.) Transport Processes in Pharmaceutical Systems. Marcel Dekker, Inc., 1999, p. 23-54.
  3. G. L. Amidon, H. Lennernas, V. P. Shah, and J. R. Crison. A theoretical basis for a biopharmaceutic drug classification: the correlation of in vitro drug product dissolution and in vivo bioavailability. Pharm. Res. 12:413-420 (1995).
  4. L. X. Yu, G. L. Amidon, J. E. Polli, H. Zhao, M. Mehta, D. P. Conner, V. P. Shah, L. J. Lesko, M.-L. Chen, V. H. L. Lee, and A. S. Hussain. Biopharmaceutics Classification System: The scientific basis for biowaiver extension. Pharm. Res. 19:921-925 (2002).
  5. S. R. Byrn, R. R. Pfeiffer, and J. G. Stowell. Solid-State Chemistry of Drugs. 2nd Edition, SSCI, Inc., West Lafayette, Indiana, pp. 259-366.
  6. H. G. Brittain and E. F. Fiese. Effect of pharmaceutical processing on drug polymorphs and solvates. In H. G. Brittain (ed.) Polymorphism in Pharmaceutical Solids. Marcel Dekker, Inc., New York, 1999, pp. 331-362.

71 CRYSTALS POLYMORPHS IN PHARMAhttp://www.fcfar.unesp.br/arquivos/475753.pdf

72 API………….POLYMORPHISM pharmaceutical ingredients (APIs).http://www.ncbi.nlm.nih.gov/pubmed/19275600

73 polymorphs and co-crystals – ICDD  POWER POINT PRESENTATION

74Thermodynamic stability and transformation of pharmaceutical  http://pac.iupac.org/publications/pac/pdf/2005/pdf/7703×0581.pdf

75http://www.imc.cas.cz/nmr/projekt/ws/springer.pdf

76  High-throughput crystallization: polymorphs, salts, co-crystalsand solvates of pharmaceutical solidshttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.85.5397&rep=rep1&type=pdf

77 Crystalline Solid – University of Utah College of Pharmacy Homepharmacy.utah.edu/pharmaceutics/pdf/Crystalline.pdf‎Form – a term encompassing all solids – polymorphs, solvates, amorphous  inPolymorphism in Pharmaceutical Solids

Links

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  8. R.B. Von Dreele, P.W. Stephens, G.D. Smith, and R.H. Blessing: The First Protein Crystal Structure Determined from X-ray Powder Diffraction Data: a Variant of T3R3 Human Insulin Zinc Complex Produced by Grinding,Acta Cryst. D 56, 1549-53 (2000).
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  13. Brunelli, M., Wright, J. P., Vaughan, G. B. M., Mora, A. J. & Fitch, A. N.: Solving Larger Molecular Crystal Structures from Powder Diffraction Data by Exploiting Anisotropic Thermal Expansion. Angew. Chem. (2003) 115, 2075–2078.
  14. T. Wessels, Ch. Baerlocher and L.B. McCusker: Single-crystal-like diffraction data from polycrystalline materials, Science (1999), 284, 477-479.
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  16. A. Altomare, C. Cuocci, C. Giacovazzo, A. Moliterni and R. Rizzi: The dual-space resolution bias correction algorithm: applications to powder data, J. Appl. Cryst. (2010). 43, 798-804.
  17. G.Oszlanyi and A. Suto: The charge flipping algorithm, Acta Cryst. (2008). A64, 123–134 and references herein.
  18. Boccaleri, E., Carniato, F., Croce, G., Viterbo, D., van Beek, W., Emerich H. and Milanesio, M.,In-situ simultaneous Raman/high-resolution X-ray powder diffraction study of transformations occurring in materials at non-ambient conditions, J. Appl. Cryst., 2007, 40, 684-693.
  19. Scarlett N.V.Y. and Madsen I. C., Quantification of phases with partial or no known crystal structures, Powder Diffraction (2006) 21, 278-284
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  22. Local structure from total scattering and atomic pair distribution function (PDF) analysis, In Powder diffraction: theory and practice, (Royal Society of Chemistry, London England, 2008), Robert E. Dinnebier and Simon J. L. Billinge, Eds., pp. 464 – 493.
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  25. P.W. Stephens, D.E. Cox, and A.N. Fitch, Synchrotron Radiation Powder Diffraction in Structure Determination by Powder Diffraction, pp. 49-87, edited by W.I.F. David, K. Shankland, L.B. McCusker, and C. Baerlocher, (Oxford University Press, 2002)
  26. Joel Bernstein: Polymorphism in Molecular Crystals, IUCr Monographs on Crystallography (2002), Oxford Science Publications.
  27. Polymorphism in Pharmaceutical Solids, Ed. By Harry G. Brittain, Drugs and The Pharmaceutical Sciences, Vol. 192
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  29. Law D, Schmitt EA, Marsh KC, Everitt EA,Wang W, Fort JJ, Krill SL, Qiu Y. Ritonavir-PEG 8000 amorphous solid dispersions: in vitro and in vivo evaluations. J. Pharm. Sci. 2004; 93 (3): 563–567.
  30. Bruni G., Berbenni V., Milanese C., Girella A., Cardini A., Lanfranconi S. and Marini A.,Determination of the nateglinide polymorphic purity through DSC, J. Pharm. and Biomed. Anal. 54 (2011) 1196-1199.
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  34. Rakowski W. A and Mazzochi D. M., The case of disappearing polymorph: ‘Inherent anticipation’ and the impact of Smithkline Beecham Corp. v Apotex Corp. (Paxil®) on patent validity and infringement by inevitable conversion’. Journal of Generic Medicine, Vol.1, No.2 (2006):131-139.
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  1. McCrone, W.C. in Physics and Chemistry of the Organic Solid State, Vol. 2, (Eds.: D. Fox, M.M. Labes, A. Weissberger), Interscience, New York, 1965, pp. 725-767.
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  3. Polymorphism in Pharmaceutical Solids, Second Edition (Drugs and the Pharmaceutical Sciences) Harry G. Brittain (Editor) Informa HealthCare; 2nd edition (July 27, 2009)
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  7. Hurst, V.J., Schroeder, P.A., and Styron, R.W. Accurate quantification of quartz and other phases by powder X-ray diffractometry. Analytica Chimica. Acta, 1997, 337, 233-252
  8. Campbell Roberts, S.N., Williams A.C., Grimsey, I.M., and Booth S.W., Quantitative analysis of mannitol polymorphs. X-ray powder diffractometry—exploring preferred orientation effects J. Pharm. Biomed. Anal., 2002, 28, 1149-1159.

SEE

PART 1………..http://drugsynthesisint.blogspot.in/p/gliptin-series.html

PART 2 ……http://organicsynthesisinternational.blogspot.in/p/gliptin-series-22.html

Gilead’s HCV drug Sovaldi gets Europe OK


Gilead's HCV drug Sovaldi gets Europe OK

Gilead Sciences’ closely-watched hepatitis C drug Sovaldi has been given the green light in Europe.

The European Commission has granted marketing authorisation for Sovaldi (sofosbuvir) 400mg tablets

which, as part of HCV combination therapy with peg-interferon and ribavirin, offers cure rates of around 90% in previously-untreated adults. However, most significant is that the once-daily nucleotide analogue polymerase inhibitor is the first all-oral treatment option for up to 24 weeks for patients unsuitable for interferon.

Read more at: http://www.pharmatimes.com/Article/14-01-20/Gilead_s_HCV_drug_Sovaldi_gets_Europe_OK.aspx#ixzz2qwHI3iJi

SYNTHESIS

  1. sofosbuvir » All About Drugs

    ALL ABOUT DRUGS BY DR ANTHONY MELVIN CRASTO, WORLD DRUG TRACKER HELPING  US Approves Breakthrough Hepatitis C Drug,Sofosbuvir.

Mast Ischemia Drug Gets Orphan Drug Designation


Wed, 11/13/2013
Mast Therapeutics Inc. announced that the U.S. Food and Drug Administration (FDA) has designated MST-188 for the treatment of acute limb ischemia as an orphan drug.http://www.dddmag.com/news/2013/11/mast-ischemia-drug-gets-orphan-drug-designation

MST-188 (purified poloxamer 188)

MST-188 is a purified form of a nonionic, triblock copolymer (poloxamer 188). It is an investigational agent that binds to hydrophobic surfaces on damaged cells and improves membrane hydration and lowers adhesion and viscosity, particularly under low shear conditions. MST-188 has the potential to reduce ischemic tissue injury and end-organ damage by restoring microvascular function, which is compromised in a wide range of serious and life-threatening diseases and conditions. We initially are developing MST-188 as a treatment for complications arising from sickle cell disease.

How MST-188 Works…

Background

Non-purified forms of poloxamer 188 (P188) have been used in foods, drugs and cosmetics since the 1950s. In the 1980s, extensive research on the mechanisms and potential clinical applications of P188 was conducted. Research has demonstrated that P188 binds to hydrophobic surfaces that develop when cells are damaged and restores normal hydrated surfaces, while having little or no activity in normal, healthy tissues. Research also has demonstrated that P188 prevents adhesion and aggregation of soluble fibrin and formed elements in the blood and maintains the deformability of red blood cells, the non-adhesiveness of unactivated platelets and granulocytes and the normal viscosity of blood. In addition, it is believed that P188 is not metabolized, but is excreted unchanged in the urine with a half-life of approximately four to six hours.

Formulations of P188 (non-purified and purified) have been studied in clinical trials involving nearly 4,000 individuals. It has been evaluated in the clinic to treat acute myocardial infarction, sickle cell disease and malaria, including a 2,950-patient, randomized, controlled study of P188 (non-purified) in acute myocardial infarction. The effectiveness of P188 also has been investigated in nonclinical studies of stroke, hemorrhagic shock, bypass surgery, adult respiratory distress syndrome, neurologic protection in deep hypothermic circulatory arrest, vasospasm, spinal cord injury, angioplasty, frostbite, amniotic fluid embolism, acute ischemic bowel disease and burns.

MST-188

Our(mast) purified form of P188, or purified P188, which is the active ingredient in MST-188, was designed to eliminate certain low molecular weight substances present in P188 (non-purified), which we believe were primarily responsible for the moderate to moderately severe elevations in serum creatinine levels (acute renal dysfunction) observed in prior clinical studies of P188 (non-purified). Purified P188 has been evaluated in multiple clinical studies by a prior sponsor, including a 255-patient, phase 3 study. In that study, purified P188 was generally well tolerated and there were no clinically significant elevations in serum creatinine among subjects who received purified P188 compared to placebo.

We believe that, as a rheologic, antithrombotic and cytoprotective agent, MST-188 has potential application in treating a wide range of diseases and conditions resulting from microvascular-flow abnormalities.

Sickle Cell Disease Market & Opportunity

More than $1.0 billion is spent annually in the U.S. to treat patients with sickle cell disease. Sickle cell disease is a genetic disorder characterized by the “sickling” of red blood cells, which normally are disc-shaped, deformable and move easily through the microvasculature carrying oxygen from the lungs to the rest of the body. Sickled, or crescent-shaped, red blood cells, on the other hand, are rigid and sticky and tend to adhere to each other and the vascular endothelium. Patients with sickle cell disease are known to experience severely painful episodes associated with the obstruction of small blood vessels by sickle-shaped red blood cells. These painful episodes are commonly known as acute crisis or vaso-occlusive crisis. Reduced blood flow to organs and bone marrow during vaso-occlusive crisis not only causes intense pain, but can result in tissue death, or necrosis. The frequency, severity and duration of these acute crises can vary considerably.

We (mast) estimate that, in the U.S., sickle cell disease results in over 95,000 hospitalizations and, in addition, approximately 69,000 emergency department treat-and-release encounters each year. When a patient with sickle cell disease makes an institutional visit, vaso-occlusive crisis is the primary diagnosis in approximately 77% of hospital admissions and 64% of emergency room treat-and-release encounters. In addition, although the number is difficult to measure, we estimate that the number of untreated sickle cell crisis events is substantial and in the hundreds of thousands in the U.S. each year. We believe that, if MST-188 is approved, as people with sickle cell disease are made aware of the new therapy, more people who suffer from acute crisis will seek treatment.

Development Status

We (mast) have initiated a Phase 3 clinical study of MST-188 for the treatment of sickle cell disease. The primary objective will be to demonstrate that MST-188 reduces the duration of vaso-occlusive crisis in patients with sickle cell disease. Please see our Clinical Trials page for more information regarding our phase 3 study of MST-188. In addition to the phase 3 study, we plan to conduct a number of smaller-scale clinical studies to further assess the efficacy, safety and tolerability of MST-188, and expect these studies to overlap with the phase 3 study.

Antifungal drugs-Antibiotics


Antifungal drugs-Antibiotics

by , Senior Lecturer at AIMST University, Malaysia on Oct 20, 2013

Sihuan Pharma’s clinical study application for oncology drug Pirotinib accepted by CFDA


The China Food and Drug Administration (CFDA) has accepted Sihuan Pharmaceutical’s application for clinical trial approval for its Pirotinib, a Category 1.1 innovative oncology drug developed by the company’s drug R&D team.

By developing Pirotinib, Sihuan Pharma has demonstrated its capability for the oncology products market. The company holds the largest cardio-cerebral vascular (CCV) drug franchise in China’s prescription market.

The new drug is a second generation (pan-HER) inhibitor intended to treat patients with lung and breast cancer.http://www.pharmaceutical-technology.com/news/newssihuan-pharmas-clinical-study-application-oncology-drug-pirotinib-accepted-cfda?WT.mc_id=DN_News

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