ABSTRACT
Bioequivalence is dened in 21 CFR 320.1 as “the absence of a signicant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study.” This denition has been emulated globally by every regulatory agency worldwide resulting in a creation of protocols and experimental designs requiring pharmacokinetic testing in humans. One assumption involved in all of these models is that since in most instances the site of action may not be accessible for sampling, the indirect testing through study of the pharmacokinetic proles allows simulation of the prole of drug concentration at the site of action.
