Investigative drug metabolism involves specialized studies designed to address complex or unique ADME challenges encountered during drug discovery and development. Unlike routine biotransformation studies, these investigations employ custom-designed, fit-for-purpose experiments and targeted approaches to uncover deeper insights into ADME in biological systems. These investigations help identify definitive structures of important metabolites and uncommon metabolic pathways, elucidate mechanisms behind unexpected pharmacokinetics or toxicity, and support decision-making in lead optimization, candidate selection, and clinical development.

Key Examples of Investigative Drug Metabolism Studies:

· Gut metabolism studies in vitro to understand microbial contributions to drug metabolism.

· Screening for microbial systems and various in vitro models for metabolite generation.

· Biotransformation characterization of slowly metabolized drugs to assess long-term metabolite exposure or major metabolic clearance.

· Metabolite quantification using radiolabeled standards for precise measurement.

· Study of protein adduction using radiolabeled compounds to evaluate potential toxicity.

· Screening for pharmacologically active or toxic metabolites in plasma and tissues.