Bioequivalence and Bioavailability
Bioavailability can be referred to as the rate and extent to which active ingredient or active element of the drug product is absorbed and becomes available at the site of action. The extent and rate of drug absorption are usually measured by the area under the blood or plasma concentration-time curve (AUC) and the maximum concentration (Cmax), respectively. For drug products that are not planned to be absorbed into bloodstream, their bioavailability may be assessed by measurements intended to reflect the rate and extent to which the active moiety of the drug product is absorbed and becomes available at the site of action.
Bioequivalence: When two drug products or two formulations of the same drug provide the same therapeutic effect, they are said to be bioequivalent, or, that they are therapeutically equivalent. It means, their rates and extent of absorptions do not reflect a significant difference at the site of action.