In Vitro Permeation Test Studies for Topical Drug Products Submitted in ANDAs

In Vitro Permeation Test Studies for Topical Drug Products Submitted in ANDAs guidance is intended to assist applicants who are submitting abbreviated new drug applications (ANDAs) for liquid-based and/or other semisolid products applied to the skin, including integumentary and mucosal (e.g., vaginal) membranes, which are hereinafter called “topical products.”² Because of the complex route of delivery associated with these products, which are typically locally acting, and the potential complexity of certain formulations, topical products (other than topical solutions) are classified as complex products.³  This guidance provides recommendations for in vitro permeation test (IVPT) studies comparing a proposed generic (test) topical product and its reference standard (RS) for the purpose of supporting a demonstration of bioequivalence (BE) to the reference listed drug (RLD). The reference standard ordinarily is the RLD.⁴