ABSTRACT
INTRODUCTION Introduction of the Biopharmaceutics Classification System (BCS) (see chap. 8) was intended to reduce in vivo bioequivalence studies, in particular for applications of generic drug products. Actually, in its simplifications, the BCS concept addresses the complex question of what affects drug substance bioavailability and when formulation effects may be considered negligible or may even be supposed to be absent. This mechanistic view of bioavailability ultimately allowed implementation of the BCS-based biowaiver into guidance documents on bioequivalence, since the bioequivalence of oral dosage forms is the primary issue for which the BCS concept can be applied in a regulatory setting.
