The Food and Drug Administration (FDA) released a pair of guidance documents intended to advance the development of generic drugs applied to a patient’s skin. These are known as transdermal and topical delivery systems (TDS). The guidances are “Assessing Adhesion With Transdermal and Topical Delivery Systems for ANDAs” and “Assessing the Irritation and Sensitization Potential of Transdermal and Topical Delivery Systems for ANDAs”. The agency also released 25 product-specific guidance documents. This comes as a part of President Trump’s drug pricing blueprint which emphasized the intent to prioritize the development of guidance to improve efficiencies in the development, review, and approval processes for generic drugs.
Guidances
The recommendations in “Assessing Adhesion With Transdermal and Topical Delivery 2 Systems for ANDAs” relate exclusively to studies submitted in support of an abbreviated new drug application (ANDA). It provides recommendations for the design and conduct of studies evaluating the adhesive performance of a transdermal or topical delivery system (TDS). Depending on the objectives of a TDS product development program, applicants may choose to evaluate TDS adhesion in studies performed to evaluate TDS adhesion only or in studies performed with a combined purpose (e.g., for the simultaneous evaluation of adhesion and bioequivalence with pharmacokinetic (PK) endpoints.
In “Assessing the Irritation and Sensitization Potential of Generic Transdermal and Topical Delivery Systems for ANDAs” the FDA provides recommendations for the design and conduct of studies to evaluate the in vivo skin irritation and sensitization potential of a proposed transdermal or topical delivery TDS. The recommendations in the guidance relate exclusively to studies submitted in support of an ANDA.
The recommendations relating to the design and conduct of irritation and sensitization studies described in this guidance replace the recommendations related to irritation and sensitization studies provided in product-specific guidances published before this guidance. Nonetheless, FDA recommends that applicants consult the guidance in conjunction with any relevant product-specific guidances that contain product specific recommendations (1) for their irritation and sensitization study (such as the strength of the TDS, the duration of wear for the specific TDS, and the frequency of scoring observations) or (2) for other in vivo studies (such as adhesion or pharmacokinetics) that may be necessary to establish the bioequivalence of a proposed generic TDS drug product to its reference listed drug and/or reference standard product.
Gottlieb Comments
FDA Commissioner Scott Gottlieb, M.D., issued a statement on the release of these documents, noting future actions coming from the agency.
“In the coming months, we’re going to advance other new policies to promote more generic competition for these complex drugs. This includes the development of new analytical tools and in vitro tests that may be more accurate and sensitive, and reproducible tools to demonstrating sameness between a generic and branded version of a complex drugs. More efficient tools for demonstrating sameness can reduce product development time and cost and inform regulatory decisions.”
Additionally, the agency will be “issuing an umbrella guidance to help generic drug developers address some of the most challenging regulatory and scientific issues encountered when they try to make generic copies of complex drugs. This umbrella guidance will be followed by a series of more targeted guidances to help address legal questions that may be blocking generic competition,” and also “clarifying our policies on how we evaluate potential differences in instructions for using complex generic drugs, for example when there are directions for how to use a specific drug delivery device in an approved drug-device combination.”