Identification and Quantification of Drugs, Metabolites and Metabolizing Enzymes by LC-MS

Dr. Chowdhury is currently a Director of DMPK at Takeda Pharmaceutical International Co. in Cambridge, MA, responsible for evaluating metabolism, toxicity, and potential for drug-drug interaction due to modulation of activities of metabolizing enzymes and transporters by compounds in discovery and development. Dr. Chowdhury obtained his Ph.D. from the University of Alberta in 1987. After spending a year and a half as a post-doctoral fellow at the University of Toronto, Dr. Chowdhury joined Rockefeller University as a Research Associate in the laboratory of Professor Brian Chait. At Rockefeller University, Dr. Chowdhury was involved in the early stage of the development of atmospheric pressure ionization (API) mass spectrometry. This early research on API led to the introduction of a novel API system for LC/MS. After leaving Rockefeller University, he worked on the applications of liquid chromatography/mass spectrometry techniques at several non-academic organizations, including at Schering-Plough Research Institute (SPRI), where he worked for fifteen years in the Department of Drug Metabolism and Pharmacokinetics. The focus of his research at SPRI was to investigate the biotransformation of drugs in support of drug discovery and development. He was involved with the development and registration of a number of pharmaceuticals including Temodar, Clarinex, Zetia, Noxafil, Nasonex/Asmanex, and Victrelis. Dr. Chowdhury is an author of nearly 100 original publications covering a broad area of drug metabolism and drug-drug interaction and analytical technologies to evaluate them.

Introduction: LC-MS and Drug Metabolism: A Journey Back in Time, Present Trends and Future Direction.


Strategies for Increasing Throughput for PK Samples in a Drug Discovery Environment.


Commonly Encountered Analytical Problems and their Solutions in Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS) Methods Uded in Drug Development.


Pitfalls in Quantitative LC-MS/MS: Metabolites Contributing to Measured Drug Concentrations.


In vitro DMPK Sreening in Drug Discovery, Role of LC-MS/MS.


Metabolite Identification by LC-MS: Applications in Drug Discovery and Development.


Screening for the Assessment of Electrophilic Metabolite Formation Early in Drug Discovery Using HPLC-MS.


Liquid chromatography Tandem Mass Spectrometry-Based Metabolite Identification Strategies in Pharmaceutical Research.


Quantification and Structural Elucidation of Low Quantities of Radiolabeled Metabolites Using Microplate Scintillation Counting (MSC) Techniques in Conjunction with LC-MS.


Oxidative Metabolites of Drugs and Xenobiotics: LC-MS Methods to Identify and Characterize in Biological Matrices.


Detection and Charactrization of Highly Polar Metabolites by LC-MS: Proper Selection of LC Column and Use of Stable Isotope Labeled Drug to Study Metabolism of Rabavirin in Rats.


Cytochrome P450 (CYP) and UDP-Glucuronosyltransferase (UGT) Enzymes: Role in Drug Metabolism, Polymorphism, and Identification of their Involvement in Drug Metabolism.