Bioavailability and Bioequivalence

Abstract

From a pharmacokinetic perspective, bioavailability relates systemic exposure to drug absorption, while helping understand mechanisms underlying drug distribution, transport, and metabolism. Bioavailability studies are also designed to demonstrate bioequivalence of test and reference formulations for both new drug and generic drug products. This chapter provides an overview of the interrelated concepts of bioavailability and bioequivalence and their application to characterize human drug disposition. Additionally, for oral drugs, the determinants of bioavailability leading to malabsorption and presystemic elimination by the gut mucosa and liver are described.