ABSTRACT
This chapter addresses nonclinical safety assessment for more conventional small molecule drugs and large molecule drugs. Drug development is often divided into three distinct areas composed of drug discovery with subsequent lead optimization, nonclinical drug development, and, finally testing of the potential drug in clinical trials. The transition between these areas is a continuum and forms the basis of translational research and medicine. Importantly, the development of new drugs involves the evaluation of both animal model (nonclinical) and human (clinical) safety information. Drug development is a highly regulated process in which specific regulatory agency criteria, including Good Laboratory Practice regulations, must be followed. Standard animal toxicology studies should include assessment of drug exposure, primarily parent drug plasma concentration. Clinical drug–drug interaction studies are conducted with small-molecule drugs during development, but very few drug interaction studies have been performed with biopharmaceuticals since they are not metabolized by the cytochrome P450 system.
