The state of the art: a commentary on the current practice of metabolism and pharmacokinetic studies in the pharmaceutical industry.

1. The role of those studying metabolism and pharmacokinetics within the safety evaluation process is discussed. 2. Current technology to undertake "classical" drugs disposition studies is adequate but some of the classical concepts may require modification in the future. 3. Problems of study design in the context of the broad objectives of regulatory requirements are reviewed. 4. The implications of new proposals which may affect the future design of metabolic and pharmacokinetic programmes are considered.