ABSTRACT: The goal of this presentation is to discuss results from a series of recent clinical studies (J. Pharm. Sci. 105:996-1005, 2016) and considerations for BCS class 3 biowaivers. In a series of recent clinical studies, the objective was to assess the impact of larger than conventional amounts of 14 commonly used excipients on BCS class 3 drug absorption in humans. Cimetidine and acyclovir were used as model class 3 drugs across three separate four-way crossover bioequivalence studies...