DR ANTHONY MELVIN CRASTO Ph.D

DR ANTHONY MELVIN CRASTO, Worlddrugtracker, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his PhD from ICT ,1991, Mumbai, India, in Organic chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with AFRICURE PHARMA as ADVISOR earlier GLENMARK LS Research centre as consultant,Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Prior to joining Glenmark, he worked with major multinationals like Hoechst Marion Roussel, now sSanofi, Searle India ltd, now Rpg lifesciences, etc. he is now helping millions, has million hits on google on all organic chemistry websites. His New Drug Approvals, Green Chemistry International, Eurekamoments 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 32 year tenure, good knowledge of IPM, GMP, Regulatory aspects, he has several international drug patents published worldwide . He gas good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, polymorphism etc He suffered a paralytic stroke in dec 2007 and is bound to a wheelchair, this seems to have injected feul in him to help chemists around the world, he is more active than before and is pushing boundaries, he has one lakh connections on all networking sites, He makes himself available to all, contact him on +91 9323115463, amcrasto@gmail.com

General Pharmacology

Uncategorized Comments Off

Dec 312018

Top 20 General Pharmacology Questions Every one of us Should Know

*Q.1 What is Pharmacology?*

Ans: Pharmacology is a branch of science that deals with the interaction of drugs with living organisms. Or The study of Pharmacokinetics and Pharmacodynamics.

*Q.2 What is a Drug?*

Ans: A drug is any chemical entity that causes a change in biological function in a living organism.some drugs are formed inside the body such as insulin and noradrenaline etc.drugs that are introduced into the body from outside are called Xenobiotics.

*Q.3 What Is a Dose?*

Ans: A Specific Amount of Drug Prescribed to be taken at one time.

*Q.4 What Is Blood Brain Barrier?*

It is A Tight Endothelial Cells Of the Brain Capillaries And Glial Cells Of The Brain Around The blood capillaries that doesn’t allow the passage of certain lipid insoluble substances to pass from the blood into the brain.Lipid Soluble Drugs can easily Cross This Barrier.Examples Of Lipid soluble Drugs are; Diazepam, Thiopental, And Phenobarbitol.

*Q.5 What is Volume Of Distribution?*

Ans: The total Volume Of The Body Fluid in which a drug appears to be distributed according to its concentration in the blood or plasma.VD of a drug can be determined by the following Formula,

VD (Volume OF Distribution) =Total Amount OF Drug In the Body/Concentration of drug in the blood plasma.

*Q.6 What Is Potency?*

Ans: It is the weight of the drug that produces a certain magnitude of response.For Example Lesser the weight of drug required to produce a given effect, more its potency.Also More the weight of the drug required to produce the same effect lesser its potency.e.g Clonidine Produce its antihypertensive effect in 0.2-0.3mg Daily Dose.While Antihypertensive dose of methyldopa is 500-2000mg Per Day.Thus Clonidine IS more Potent than methyldopa.

*Q.7 What Is Efficacy?*

Ans:If the dose of a drug is increased its effect will be increased proportionately, until a stage is reached beyond there is no further increase in effect will occur,even if a large dose of drug is given.thix maximum effect of drug beyond which no further increase in its effect occurs even if the dose of the drug is increased to a large amount is called efficacy or maximal efficacy.example morphine has more efficacy than aspirin as an analgesic .morphine is more effective in the severe type of pains while aspirin is effective in mild to moderate pain.

*Q.8 What is Therapeutic index?*

The ratio between median toxic dose (TD50) and median effective dose (ED50) is called therapeutic index.

Therapeutic index= TD50/ED50

*Q.9 What is idiosyncrasy?*

It is a rare type of response to a drug that is not related to its dose, that is, even a small dose can cause it.For example.A rare adverse effect with chloramphenicol is aplastic anemia.

*Q.10 What is Hypersensitivity?*

An allergic or immunological response to a drug .for example anaphylactic shock with penicillin is a severe type of hypersensitivity reaction.

*Q.11 What is Tolerance?*

Ans: Repeated use of a drug causes a gradual decrease in the response to the drug.e.g chronic use of morphine will decrease many of its effects in the body, therefore the dose of the drug has to be increased with the passage of time to maintain the usual effects of the drug.

*Q.12 What is a Receptor?*

Ans: Receptor is a macromolecule (Big molecule).Most of the receptors are protein in nature.mostly those drugs that act on the cells bind to the receptors.Those drugs which bind to the receptor and show their effect are called agonists.While some drugs bind to the receptor but don’t produce an effect.These drugs are known as an antagonist as they prevent the binding of agonists with the receptors.

*Q.14 What is the adverse drug reaction?*

Drugs may produce two types of effect i.e Useful effects and harmful effects.harmful effects are also known as adverse drug reaction or undesired effects.These effects may range from the mild type of adverse effect to severe effects that may cause a death of the person.

Adverse drug reaction may be classified into the following types;

Idiosyncrasy

Drug allergy

Direct toxic effect

Drug dependence

Tolerance

*Q.15 What is Shock?*

It is a clinical condition in which there is an inadequate supply of blood to tissues.it causes hypotension, oliguria, and metabolic acidosis.Following are the common types of shock:

A. Hypovolemic shock

B. Septic shock

C. Cardiogenic shock

D. Anaphylactic shock

*Q.16 What is Drug Clearance?*

Ans: It Can be defined as Volume Of blood or plasma cleared of the drug in a unit period of time.Thus, to determine clearance we have to find that volume of blood or plasma from which a drug is removed during a unit period of time.By removal of drug we mean metabolism and excretion of drug.if we know the clearance of a drug we can adjust its dose properly.clearance of the drug can be determined by the following formula.

Cl: Rate of elimination/Concentration of drug in the blood

Where is Cl is clearance?

*Q.17 What is Drug Excretion?*

Ans: Removal of drugs from the body is known as their excretion.Drugs are excreted from the body either in the form of their metabolites or in unchanged form.Excretion can occur from the following routes;

A) Faecal

B) Renal

C) Biliary

D)Pulmonary

E)Others like to sweat, saliva, milk etc

*Q.18 What is Toxicology?*

It is an aspect of pharmacology that deals with the adverse effects of drugs on living organisms .in addition to drugs used in therapy, it also deals with many other chemicals that may be responsible for the household, environmental, or industrial intoxication.

*Q.19 What is antidote?*

Ans: Antidotes are Any Substance which Is Used To oppose the effects of poisons without causing any damage to The body. Example antidote for benzodiazepine is flumazenil.

*Q.20 What is Bioavailability?*

It can be defined as a fraction of unmodified drug reaching into the systemic circulation after it is administered by any route.IV administration of drug produces 100% bioavailability as a whole of the drug enters the systemic circulation.Oral administration of the drug may not produce 100% bioavailability due to incomplete absorption of a drug from the Gastrointestinal tract and due to first pass effects of some of the drugs.

[29/12, 10:20 AM] ‪+91 93017 24365‬: *Sun Pharma arm gets relief from US court in patent infringement case*

_The lawsuit alleged trade secret misappropriation and patent infringement of DUSA’s photodynamic therapy patents covering its product._

: Sun Pharma Wednesday said, DUSA Pharmaceuticals, an arm of of the Mumbai based pharma giant, has received relief from a US court in a patent infringement case.

Massachusetts-based DUSA has been granted preliminary injunctive relief by a federal district court prohibiting defendants Biofrontera Inc, Biofrontera Bioscience GmbH, Biofrontera Pharma GmbH, and Biofrontera AGf from using its confidential and proprietary trade secret information, Sun Pharmaceutical Industries said in a regulatory filing.

Earlier this year, DUSA, which is wholly-owned by Sun Pharma, filed a lawsuit against the Biofrontera defendants in the US District Court for the District of Massachusetts.

The lawsuit alleged trade secret misappropriation and patent infringement of DUSA’s photodynamic therapy patents covering its product.

DUSA, in its amended complaint filed in July 2018, additionally alleged the Biofrontera defendants misappropriated confidential and trade secret information by obtaining confidential information from its former employees to sell and market defendants’ own products.

The lawsuit sought an assessment of both damages and injunctive relief against the Biofrontera defendants, Sun Pharma said.

The court’s order prohibits Biofrontera from making use of or disseminating DUSA’s sales and financial information, customer lists and customer target lists, training and marketing materials, standard operating procedures, technical information, and unpublished clinical data, and any derivations thereof, effective immediately, it added.

[29/12, 10:32 AM] ‪+91 93017 24365‬: **CDSCO tightens safety & labelling rules for acne drug isotretinoin, prescription mandatory*The Central Drugs Standard Control Organisation (CDSCO) has tightened safety guidelines and labelling rules for isotretinoin capsules, an oral drug used for the treatment and prevention of severe acne, citing harmful side effects and adverse reactions. The national drug regulator is learnt to have taken the action following complaints received by the Centralised Public Grievance Redress and Monitoring System.

The stricter regulations for manufacture and retail of isotretinoin were recommended by the CDSCO’s Subject Expert Committee for dermatology and allergy at its recent meeting.

Isotretinoin is an oral derivative of vitamin A. According to clinicians, the medication is prescribed to people who have severe and painful acne that affects their quality of life. The average course of treatment is 4-6 months. It is available in India under various brand names such as Zenatane, Isotroin, Retinon, Aktret, Ratino and Isopad. Many users also obtain the product online.

Isotretinoin’s 10mg and 20mg capsules were approved by the CDSCO way back in 2002 for treatment of severe nodular acne that were unresponsive to antibiotic therapy. The nod was given with various conditions including box warning on packs for female patients as the drug may cause severe birth defects.

Making the rules more rigorous, the national regulator has ordered drug controllers of all states and Union Territories to ensure that the medicine is sold on prescription of dermatologists only. Moreover, chemists should maintain details of the sale as per requirements of Drugs & Cosmetics Rules of 1945.

The drug pack should henceforth carry the following *box warning* : *“This medicine may cause severe birth defects; you must not take this medicine if you are pregnant or may likely become pregnant during treatment. You should also avoid pregnancy for 6 months after stopping the treatment”.*

READ

ANTHONY MELVIN CRASTO

https://newdrugapprovals.org/

DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO …..FOR BLOG HOME CLICK HERE

amcrasto@gmail.com

CALL +919323115463 INDIA

//////////////

Combination of Enantioselective Preparative Chromatography and Racemization: Experimental Demonstration and Model-Based Process Optimization

PROCESS, SYNTHESIS Comments Off

Dec 122018

Conventional enantioselective preparative chromatographic separation using columns packed with chiral stationary phase is characterized by a 50% yield constraint. Racemization of the undesired enantiomer and recycling the formed mixture is an attractive option to tackle this limit. To implement this concept, potential is seen in particular in applying enzymes immobilized in a second fixed bed. However, the identification of suitable operating conditions and the direct connection of a chromatographic column and an enzymatic reactor is not trivial. The paper presents results of an experimental study applying jointly a batch-wise operated chiral Chirobiotic T column to resolve the two enantiomers of mandelic acid (MA) and a mandelate racemase immobilized on Eupergit CM. The general concept could be successfully demonstrated over several cycles focusing on the provision of (S)-MA. A mathematical model was developed in order to illustrate essential process features and to quantitatively describe the coupled separation and racemization processes. The key ingredients of this model, namely, the adsorption isotherms of the two enantiomers on the chiral column and the rate of racemization in the enzymatic reactor, were determined experimentally. The potential of applying the model for further process optimization and generalization is indicated.

Combination of Enantioselective Preparative Chromatography and Racemization: Experimental Demonstration and Model-Based Process Optimization

Katarzyna Wrzosek*^†

, Isabel Harriehausen^†, and Andreas Seidel-Morgenstern^†^‡

^† Max-Planck Institute for Dynamics of Complex Technical System, Physical and Chemical Foundations of Process Engineering, 39106 Magdeburg, Germany

^‡ Otto von Guericke University, Chemical Process Engineering, 39106 Magdeburg, Germany

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.8b00254

*E-mail: wrzosek@mpi-magdeburg.mpg.de. Tel.: +49 391 6110 321.

link https://pubs.acs.org/doi/10.1021/acs.oprd.8b00254

Image result for Magdeburg, Germany max planck

Dr. Katarzyna Wrzosek

Katarzyna Wrzosek

Dr. Katarzyna Wrzosek

Phone:+49 391 6110 321

Max-Planck Institute for Dynamics of Complex Technical System, Physical and Chemical Foundations of Process Engineering, 39106 Magdeburg, Germany

*E-mail: wrzosek@mpi-magdeburg.mpg.de.

M. Sc. Isabel Harriehausen

Isabel Harriehausen

M. Sc. Isabel Harriehausen

Phone:+49 391 6110 447 harriehausen@mpi-magdeburg.mpg.de

Prof. Dr.-Ing. Andreas Seidel-Morgenstern

Andreas Seidel-Morgenstern

Prof. Dr.-Ing. Andreas Seidel-Morgenstern

Phone:+49 391 6110 401

Email: seidel-morgenstern@mpi-magdeburg.mpg.de

Magdeburg, Germany

Image result for Magdeburg, Germany max planck

Image result for Magdeburg, Germany

Grüne Zitadelle Von Magdeburg

Image result for Magdeburg, Germany

Magdeburg Cathedral

READ

ANTHONY MELVIN CRASTO

https://newdrugapprovals.org/

DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO …..FOR BLOG HOME CLICK HERE

amcrasto@gmail.com

CALL +919323115463 INDIA

///////////////enantioselective chromatography, enzymatic reactor, equilibrium dispersion model, mandelate racemase, racemization

Orochem Molecular Purification by Design

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Dec 102018

Established in 1996, Orochem Technologies Inc. started as a Biotech and Chromatography company to manufacture unique Sample Prep Technology “Products” for the Bioanalysis, Drug Discovery, and the Genomics and Proteomics markets.

Established in 1996, Orochem Technologies Inc. started as a Biotech and Chromatography company to manufacture unique Sample Prep Technology Products for the Bioanalysis, Drug Discovery, and the Genomics and Proteomics markets. Backed with unique expertise in high throughput formats, membranes and surface chemistries, Orochem was one of the first companies to translate the concept of pre-filters from single to high throughput formats, a concept now widely implemented for sample prep plates in the biotech and analytical markets. In the year 2001 Orochem manufactured the first commercially available Protein Crash and Precipitation 96-well plate for Bioanalytical processes. By the year 2006, with the acquisition of Column Engineering Inc, Orochem evolved to become a “full-service” provider for silica manufacturing utilized for analytical and preparatory chromatography. Orochem invests heavily into R&D in-house and owns strong intellectual property in stationary phases for achiral and Chiral Chromatography.

Orochem’s is globally recognized as an organization that conceives, develops, and installs some of the most technologically viable solutions for “highest purities” for industrial or “metric ton” scale purification for API’s, nutritional supplements, fatty acids, and specialty sugars. Orochem provides Simulated Moving Bed (SMB) Chromatography technology for the laboratory scale, pilot scale and large-scale purification of commercially viable molecules for its customers around the world. Orochem’s products and services for Simulated Moving Bed Chromatography include Synthesis and manufacture of stationary phases “tailored for specific separations”, a uniquely engineered SMB system and the installation and commissioning of the SMB systems at customer sites with well-trained Orochem technical service engineers.

Orochem owns several manufacturing facilities around the world. The Naperville, Illinois, USA site has about 84,000 square feet of manufacturing area where most of the Membrane Filter Plates, Silica manufacturing, Silica bonding, Solid Phase Extraction products and HPLC Columns are manufactured. Orochem India, Mumbai has 20,000 square feet facility and manufactures Sample prep products for the Discovery & Clinical Research organizations in Asia. Simulated Moving Bed chromatography systems are designed, built and assembled completely at our US locations in Naperville in Illinois.

USA (HQ)

Orochem Technologies Inc.
   630 210 8300
   630 210 8315
   info@orochem.com
   340 Shuman Blvd., Naperville, 60563, IL.

Orochem Molecular Purification by Design

https://orochem.com/

(1S,4R)-2-(4-Methoxybenzoyl)bicyclo[2.2.2]octa-2,5-diene

spectroscopy, SYNTHESIS Comments Off

Dec 102018

(1S,4R)-2-(4-Methoxybenzoyl)bicyclo[2.2.2]octa-2,5-diene (3a) Yellow liquid (25.2 mg, 95% yield):

1H NMR (300 MHz, CDCl3)   1.39 (s, 4H, alkyl), 3.77-3.80 (m, 1H, alkyl), 3.85 (s, 3H, OMe), 4.36 (d, J = 5.4 Hz, 1H, alkyl), 6.36 (dd, J = 6.0, 6.0 Hz, 1H, vinyl), 6.46 (dd, J = 6.0, 6.0 Hz, 1H, vinyl), 6.88-6.91 (m, 3H, vinyl + arom.), 7.67 (d, J = 8.3 Hz, 2H, arom.);

13C{1H} NMR (75 MHz, CDCl3)  = 24.7, 24.8, 37.1, 38.2, 55.4, 113.3, 130.8, 131.5, 133.2, 135.1, 146.5, 147.7, 162.6, 192.3;

HRMS (ESI-TOF) m/z calculated for C16H16NaO2 [M+Na]+ 263.1048, found 263.1036;

FT-IR (neat, cm-1 ) 1033, 1174, 1255, 1354, 1600, 1637, 1730, 2870, 2957, 3054.

Optical Rotation: []D 26 +39.9 (c 2.52, CHCl3) for an enantiomerically enriched sample of 94% ee.

HPLC analysis (column, CHIRALPAK AD-3, hexane/2-propanol = 98/2, flow rate 1.0 mL/min, 20 C, detection UV 250 nm light); tR of major-isomer 20.7

Org. Lett., 2018, 20 (23), pp 7353–7357

DOI: 10.1021/acs.orglett.8b02263

////////////////

(1S,4R)-2-(4-Methoxybenzoyl)bicyclo[2.2.2]octa-2,5-diene

Permalink spectroscopy, SYNTHESIS Comments Off

Nov 302018

Sodium aluminate is presented as a highly active heterogeneous catalyst that is able to convert a range of alcohols into the corresponding unsymmetrical carbonate esters by reaction with dimethyl carbonate. Preparing NaAlO₂ via spray drying boosts the basic properties and the activity of the catalyst.

https://pubs.acs.org/doi/10.1021/acs.oprd.8b00333

/////////////https://pubs.acs.org/doi/suppl/10.1021/acs.oprd.8b00333/suppl_file/op8b00333_si_001.pdf

carboxymethylation, dimethyl carbonate, mixed carbonate esters, sodium aluminate,

Anthony Crasto conferred ABPnews award for “Outstanding contribution to Education Sector”

ANTHONY CRASTO, award Comments Off

Nov 282018

Conferred prestigious award at event ABP News Presents Healthcare Leadership Awards 26th November, 2018 at Taj Lands End, Mumbai India
Dedicated to Shobha Crasto Aishal crasto Lionel crasto
Service to education is service to humanity
Society recognises efforts done towards it

/////////////award, event ABP News, Healthcare, Leadership, 26th, November, 2018, Taj Lands End, Mumbai, India, education, anthony crasto

Use of Lipase Catalytic Resolution in the Preparation of Ethyl (2S,5R)-5-((Benzyloxy)amino)piperidine-2-carboxylate, a Key Intermediate of the β-Lactamase Inhibitor Avibactam

PROCESS, SYNTHESIS Comments Off

Nov 242018

Here we describe an efficient and cost-effective chemoenzymatic synthesis of the β-lactamase inhibitor avibactam starting from commercially available ethyl 5-hydroxypicolinate hydrochloride. Avibactam was synthesized in 10 steps with an overall yield of 23.9%. The synthetic route features a novel lipase-catalyzed resolution step during the preparation of (2S,5S)-ethyl 5-hydroxypiperidine-2-carboxylate, a valuable precursor of the key intermediate ethyl (2S,5R)-5-((benzyloxy)amino)piperidine-2-carboxylate. Our synthetic route was used to produce 400 g of avibactam sodium salt.

Use of Lipase Catalytic Resolution in the Preparation of Ethyl (2S,5R)-5-((Benzyloxy)amino)piperidine-2-carboxylate, a Key Intermediate of the β-Lactamase Inhibitor Avibactam

Tao Wang^†^§, Liang-Dong Du^‡, Ding-jian Wan^‡, Xiang Li^‡, Xin-Zhi Chen*^§

, and Guo-Feng Wu*^†

^† Research &Development Center, Zhejiang Medicine Co., Ltd, 59 East Huangcheng Road, Xinchang, Zhejiang 312500, P. R. China

^‡ Shanghai Laiyi Center for Biopharmaceuticals R&D, 5B, Building 8 200 Niudun Road Pudong District, Shanghai 201203, P. R. China

^§ Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang University, 38 Zhejiang University Road, Xihu District, Hangzhou 310007, P. R. China

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.8b00173

Publication Date (Web): November 5, 2018

*E-mail: xcwuyuanzhang@163.com., *E-mail: xzchen@zju.edu.cn.

https://pubs.acs.org/doi/10.1021/acs.oprd.8b00173

///////////lipase, resolution, avibactam

Latest artificial glucose-binding receptor is best yet

diabetes, Uncategorized Comments Off

Nov 202018

It’s a receptor that binds glucose strongly and with the highest selectivity yet. Could help with #diabetes treatment: http://ow.ly/EPzn30mDYjf

Read all at

https://cen.acs.org/biological-chemistry/Latest-artificial-glucose-binding-receptor/96/i46?platform=hootsuite

Carbanio – a digital B2B platform to buy and sell Chemicals in India

Uncategorized Comments Off

Nov 022018

Hello All

I have an exciting news which I want to share today.

Couple of days ago, I was browsing on the internet to see if we can buy ready stock of Chemicals online, especially from Indian Suppliers.

I was surprised to see that there is one stunning B2B Marketplace which is specially meant for ready stock of Chemicals in India.

Carbanio (www.carbanio.com) is showing promising future for all Indian Suppliers which helps them not only buy Chemicals within India, but also to Sell Chemicals. They are no registration charges and no charges to publish Chemical products. Hope they are going to launch internationally very soon which will boost exports from India.

This is really a great news for everyone who would like to generate more revenue by selling online. Online sales will not only help you in increasing revenue, but also will enable you to do business 24*7. In addition, you will also receive new requirements from their Buyers which will help you in scaling your business and portfolio.

To know more about the selling benefits, visit https://www.carbanio.com/sell-on-carbanio

Those who wish to buy, the biggest benefit of this platform is you can buy ready stock and get it delivered at your doorstep with assured Purity and Quality. I see there are huge discounts offered by their registered Sellers, which will be a cost benefit factor.

Another plus point in this site is, you can post your Chemical requirements in case if that is not available on the platform, they will help you in sourcing it for you!

To know more about the buying benefits, visit https://www.carbanio.com/buyer

For free registration, please visit https://www.carbanio.com/register

In case if you still want to know more, you can get in touch with them via businesssupport@carbanio.com

Md. Ayesha Parveen (CEO at Carbanio)

see article on linkedin

https://www.linkedin.com/pulse/digitizing-sales-chemical-industry-ayesha-md/

Ayesha MD

CEO@Carbanio

ayesha@carbanio.com

Carbanio

Businesssupport@carbanio.com

API, Impurities and Regulatory aspects

regulatory, Uncategorized Comments Off

Oct 242018

The impurities in pharmaceuticals are unwanted chemicals that remain with the active pharmaceutical ingredients (APIs) or develop during formulation or upon aging of both API and formulation. The presence of these unwanted chemicals even in trace amount may influence the efficacy and safety of pharmaceutical product

Impurities is defined as an entity of drug substances or drug product that is not chemical entity defined as drug substances an excipients or other additives to drugproduct.

The control of pharmaceutical impurities is currently a critical issue to the pharmaceutical industry. Structure elucidation of pharmaceutical impurities is an important part of the drug product development process. Impurities can have unwanted pharmacological or toxicological effects that seriously impact product quality and patient safety. Potential sources and mechanisms of impurity formation are discussed for both drugs. The International Conference on Harmonization (ICH) has formulated a workable guideline regarding the control of impurities. In this review, a description of different types and origins of impurities in relation to ICH guidelines and, degradation routes, including specific examples, are presented. The article further discusses measures regarding the control of impurities in pharmaceuticals substance and drug product applications.

Impurities in pharmaceuticals are the unwanted chemicals that remain with the active pharmaceutical ingredients (APIs), or develop during formulation, or upon aging of both API and formulated APIs to medicines. The presence of these unwanted chemicals even in small amounts may influence the efficacy and safety of the pharmaceutical products.

According to ICH, an impurity in a drug substance is defined as-“any component of the new drug substance that is not the chemical entity defined as the new drug substance”. There is an ever increasing interest in impurities present in APIs recently, not only purity profile but also impurity profile has become essential as per various regulatory requirements. The presence of the unwanted chemicals, even in small amount, may influence the efficacy and safety of the pharmaceutical products.

“In the pharmaceutical world, an impurity is considered as any other organic material, besides the drug substance, or ingredients, arise out of synthesis or unwanted chemicals that remains with API’s”

The control of pharmaceutical impurities is currently a critical issue to the pharmaceutical industry. The International Conference on Harmonization (ICH) has formulated a workable guideline regarding the control of impurities.

CLASSIFICATIONS OF IMPURITIES:
Impurities have been named differently or classified as per the ICH guidelines as follows:

A] Common names
1. By-products
2. Degradation products
3. Interaction products
4. Intermediates
5. Penultimate intermediates
6. Related products
7. Transformation products

B] United State Pharmacopeia
The United States Pharmacopoeia (USP) classifies impurities in various sections:
1. Impurities in Official Articles
2. Ordinary Impurities
3. Organic Volatile Impurities

C] ICH Terminology
According to ICH guidelines, impurities in the drug substance produced by chemical synthesis can broadly be classified into following three categories –
1. Organic Impurities (Process and Drug related)
2. Inorganic Impurities
3. Residual Solvents

Organic impurities may arise during the manufacturing process and or storage of the drug substance may be identified or unidentified, volatile or non-volatile, and may include
1. Starting materials or intermediates
2. By-products
3. Degradation products

Impurities are found in API’s unless, a proper care is taken in every step involved throughout the multi-step synthesis for example; in paracetamol bulk, there is a limit test for p-aminophenol, which could be a starting material for one manufacturer or be an intermediate for the others. Impurities can also be formed by degradation of the end product during manufacturing of the bulk drugs.

The degradation of penicillin and cephalosporin are well-known examples of degradation products. The presence of a β-lactam ring as well as that of an a-amino in the C6 or C7 side chain plays a critical role in their degradation.

The primary objectives of process chemical research are the development of efficient, scalable, and safe reproducible synthetic routes to drug candidates within the developmental space and acting as a framework for commercial production in order to meet the requirement of various regulatory agencies. Therefore, assessment and control of the impurities in a drug substance and drug product are important aspects of drug development for the development team to obtain various marketing approvals. It is extremely challenging for an organic chemist to identify the impurities which are formed in very small quantities in a drug substance and wearisome if the product is nonpharmacopeial. A study describes the formation, identification, synthesis, and characterization of impurities found in the preparation of API. A study will help a synthetic organic chemist to understand the potential impurities in API synthesis and thereby obtain the pure compound.

Care to taken ensure that desired drug metabolism, safety and clinical studies are not jeopardized by inconsistent purity or impurities having potential harmful toxicological properties,

As regulatory guidelines promulgated by the International Conference on Harmonization (ICH)(1) dictate rigorous identification of impurities at levels of 0.1%,

It is important to develop commercially viable processes for drug substance manufacture to allow greater and more affordable access in the health care sector. In regard to the process development of drug substances, it is essential to know the origin and method of control of any unwanted substances present in it. The limit should be controlled under the threshold of toxicological concern (TTC) for the purpose of ensuring safety and efficacy of the drug and to meet the requirements of various drug regulatory agencies.(2,3)

The impurities in drug substances mostly come from starting substrates, reagents, solvents, and side reactions of the synthetic route employed. Therefore, assessment and control of the undesired substances is an essential aspect of the drug development journey, with special consideration of patient health risk.(4,5)

The isolation/synthesis and characterization of process-related critical impurities (more difficult to control under the desired regulatory limits) of any drug substance in order to evaluate their origin/fate and thereafter their control strategies in the developed process as per International Council for Harmonisation (ICH) guidelines.(4)

The goal of pharmaceutical development is to develop process understanding and control which will yield procedures that consistently deliver products possessing the desired key quality attributes. To achieve this, the quality by design (QbD) paradigm has been employed in combination with process-risk assessment strategies to systematically gather knowledge through the application of sound scientific approaches.(6)

Ganzer et al. recently published an article about critical process parameters and API synthesis.(7) The article presented an in-depth discussion of a stepwise, process risk assessment approach to facilitate the identification and understanding of critical quality attributes, process parameters, and in-process controls. The primary benefit of working within the QbD conceptual framework and employing process risk assessment strategies is the reproducible delivery of high-quality active pharmaceutical ingredient (API). However, a secondary benefit is the ability to obtain regulatory flexibility with respect to filing requirements.(8)

The control of impurities observed in an API is critical in delivering an API of high quality. Identification and understanding of the mechanism of formation of process-related impurities are critical pieces of information required for the development of control strategies. In addition, to ensure a continuing supply of API for drug product clinical manufacture, timely identification of key impurities is essential. These synthesis-related impurities and their precursors are considered as critical impurities because they directly affect the quality and impurity profile of the API. It is our practice that critical impurities be identified if practicable. Therefore, the timely identification of critical impurities becomes an integral part of process development.

There are different approaches to the identification of impurities. Described, herein, a general strategy that we have used in our laboratory, which leads to the rapid identification of impurities. To identify the structure of a low-level unknown impurity, we usually use liquid chromatography/mass spectrometry (LC/MS)/high-resolution MS (HRMS) and tandem MS (MS/MS) for molecular weight (MW) determination, elemental composition, and fragmentation patterns. On the basis of the mass spectrometric data and knowledge of the process chemistry, one or more possible structure(s) may be assigned for the impurity, with definitive structure information obtained by inspection of the HPLC retention time, UV spectrum, and MS profile of an authentic compound.

If an authentic sample is not available, the isolation of a pure sample of the impurity is undertaken for structure elucidation using NMR spectroscopy. The isolation of low-level impurities is usually conducted using preparative HPLC chromatography

REFERENCES

1 ICH Q3A Impurities in New Drug Substances, R2; International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH): Geneva, Switzerland, October 2006; http://www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/Quality/Q3A_R2/Step4/Q3A_R2__Guideline.pdf.

2. Patil, G. D.; Kshirsagar, S. W.; Shinde, S. B.; Patil, P. S.; Deshpande, M. S.; Chaudhari, A. T.; Sonawane, S. P.; Maikap, G. C.; Gurjar, M. K.Identification, Synthesis, and Strategy For Minimization of Potential Impurities Observed In Raltegravir Potassium Drug Substance. Org. Process Res. Dev. 2012, 16, 1422– 1429, DOI: 10.1021/op300077m
3. Huang, Y.; Ye, Q.; Guo, Z.; Palaniswamy, V. A.; Grosso, J. A. Identification of Critical Process Impurities and Their Impact on Process Research and Development. Org. Process Res. Dev.2008, 12, 632– 636, DOI: 10.1021/op800067v

4. ICH Harmonised Tripartite Guideline Q3A(R): Impurities in New Drug Substances; International Conference on Harmonization: Geneva, 2002.

5. Mishra, B.; Thakur, A.; Mahata, P. P. Pharmaceutical Impurities: A Review. Int. J. Pharm. Chem.2015, 5 (7), 232– 239

6 International Conference on Harmonisation (ICH) Guidelines; Q8, Pharmaceutical Development, 2005; Q9, Quality Risk Management, 2006.

7 Ganzer, W. R.; Materna, J. A.; Mitchell, M. B.; Wall, L. K. Pharm. Technol. 2005, July 2) 1–12.

8 Nasr, M. Drug Information Association Annual Meeting, Philadelphia, PA, June 19, 2006; Pharmaceutical Quality Assessment System (PQAS) in the 21st Century, 2006.

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