ABSTRACT
The Food and Drug Administration (FDA) guidance provides recommendations to sponsors and/or applicants planning to include bioavailability (BA) and bioequivalence (BE) information for drug products in investigational new drug applications, new drug applications (NDAs), and NDA supplements. This FDA guidance contains advice on how to meet the BA and BE requirements set forth in 21 CFR Part 320 as they apply to dosage forms intended for oral administration. Under FDA’s regulations, applicants must use the most accurate, sensitive, and reproducible method available to demonstrate BA or BE of a product. As noted in 21 CFR 320.24, several in vivo and in vitro methods can be used to measure BA and to establish BE. These include, in general order of preference, pharmacokinetic studies, in vitro tests predictive of human in vivo BA, pharmacodynamic studies, studies with clinical benefit endpoints, and other in vitro studies.
