ABSTRACT
This chapter discusses the application, progress, and future perspectives of mass spectrometry (MS) technology in detection and structural characterization of drug metabolites in the discovery and development settings. Prior to the introduction of atmospheric pressure ionization in 1990s, identifying a metabolite by MS in complex biological matrices was a major undertaking. The use of stable isotopes has become commonplace in drug metabolism research. Coupled with stable isotope labeling techniques, gas chromatography /MS has proven to be a powerful tool for investigating mechanistic aspects of biotransformation reactions. One of the most important uses of MS is the generation and determination of molecular ions of unknown metabolites. The advance of High-Resolution Mass Spectrometry-based technologies has led to development of new analytical approaches to different types of drug metabolism studies. Drug metabolism plays an important role in understanding drug safety and efficacy in preclinical animals and patients.
