Cutaneous Pharmacokinetic Approaches to Compare Bioavailability and/or Bioequivalence for Topical Drug Products

The evaluation of bioequivalence (BE) involves comparing the test product to its reference product in a study whose fundamental scientific principles allow inferring of the clinical performance of the products. Several test methods have been discussed and developed to evaluate topical bioavailability (BA) and BE. Pharmacokinetics-based approaches characterize the rate and extent to which an active ingredient becomes available at or near its site of action in the skin. Such methodologies are considered to be among the most accurate, sensitive, and reproducible approaches for determining the BA or BE of a product.