In vitro studies in drug discovery and development: an analysis of study objectives and application of good laboratory practices (GLP).

In vitro drug metabolism studies play a dual role along the path from drug discovery to preclinical development. By analyzing the objectives of each type of study the question of whether to apply good laboratory practices (GLP) requirements is clarified. This review outlines the various in vitro techniques available and categorizes the goals for which they are applied as either supporting drug discovery or influencing decisions of clinical safety. Based on this categorization it is proposed that studies performed to explore the utility of a potential drug candidate be conducted non-GLP, while studies used to support IND and post-IND submissions be considered for GLP.