Assessing the Irritation and Sensitization Potential of Transdermal and Topical Delivery Systems for ANDAs; Revised Draft Guidance for Industry; Availability

The Food and Drug Administration (FDA or Agency) is announcing the availability of a revised draft guidance for industry titled "Assessing the Irritation and Sensitization Potential of Transdermal and Topical Delivery Systems for ANDAs." This revised draft guidance provides recommendations for the design and conduct of studies to evaluate the in vivo skin irritation (and sensitization, if applicable) potential of a proposed transdermal or topical delivery system (collectively referred to as TDS). The recommendations in this revised draft guidance relate to studies submitted in support of an abbreviated new drug application (ANDA). The revised draft guidance is intended to clarify FDA's recommendations and expectations related to in vivo skin irritation and in vivo combined skin irritation and sensitization studies. This draft guidance replaces the draft guidance "Assessing the Irritation and Sensitization Potential of Transdermal and Topical Delivery Systems for ANDAs" (April 2023).

Abstract as published in the Federal Register.

The comment window is still open until October 2, 2026. This is the point where industry shapes the final rule — submit comments through the Federal Register document below.

The complete document — every provision, the docket, and the comment instructions — is published in the Federal Register. SPEQ surfaces and indexes it for reference; the authoritative text lives on federalregister.gov.