Importance of stereospecific bioanalytical monitoring in drug development

The role of the bioanalyst in the support of drug discovery and development is described with particular emphasis upon stereospecific assays for the individual optical isomers of chiral drugs. The significance of the stereochemical aspects of pharmacokinetics and drug metabolism in both preclinical and clinical development is summarized and illustrated with reference to the pharmacogenetic polymorphisms of drug oxidation existing in the human population. The significance of stereochemical considerations in drug metabolism and pharmacokinetics has recently become an issue for both the pharmaceutical industry and the regulatory authorities, driven to a great extent by recent developments in methodology for both the analytical and preparative resolution of racemic drug mixtures. This has led to the so-called 'racemate-versus-enantiomer' debate in recent years. The development of regulatory attitudes in the major jurisdictions of the world to the development of new drugs containing one or more chiral centres is outlined.