**6. Summary**

Drug metabolism is a drug-clearing event from systemic circulation influencing efficacy and toxicity in humans and preclinical species. The primary endpoints of enzymatic metabolism studies in both the drug discovery and preclinical stages are to resolve metabolic stability, identify and quantify primary metabolites, identify metabolic routes, and measure the potential for DDIs and are used to predict human PK. The intrinsic kinetic properties of the chemical entity with consideration of the physiological processes can be used to assess the disposition of single and multiple dose escalation studies, identify potentially saturable hepatic and transporter pathways, and assess the formation of metabolites. From this information, potential DDIs are predicted and subsequently investigated.
