When applied to a patient’s skin, Transdermal/ Topical products are expected to deliver the correct dose of the medication consistently and for the expected length of time, while adhering consistently and uniformly to the skin, even when the skin is exposed to water, humid environment and/or body movement.
ANDA Guidance document for assessing Irritation and Sensitization:
This 12-page guidance provides recommendations for Abbreviated New Drug Application (ANDA) sponsors on the design and conduct of studies to evaluate the in vivo skin irritation and sensitization (I/S) potential of a proposed transdermal or topical delivery system.
Applicants must perform a comparative assessment of the generic and reference listed transdermal/topical drug products using an appropriately designed skin I/S study with human subjects. The draft document demonstrates that the potential for a skin irritation or sensitization reaction with the Test-TDS is no worse than the reaction observed with the Reference-TDS.
Study design and conduct, considerations for statistical analysis, overall assessment of adverse event data and format of data submissions are outlined in the draft guidance. (Note: The recommendations relating to the design and conduct of I/S studies described in this guidance replace the recommendations related to I/S studies provided in product-specific guidances published before this guidance. This set the stage for revisions in bioequivalence (BE) study guidelines for 23 TDS products).
ANDA Guidance document for Assessing Adhesion
This revised 9-page draft guidance supersedes a draft from June 2016 and provides recommendations for the design and conduct of studies evaluating the adhesive performance of a TDS.
Apropos the guidance document, depending on the objective(s) of a transdermal/ topical dosage form product development program, applicants may choose to evaluate transdermal /topical adhesion in clinical studies performed to evaluate adhesion only or in clinical studies performed with a combined purpose (example- for simultaneous evaluation of adhesion and bioequivalence (BE) with pharmacokinetic (PK) endpoints).
Additional topics covered in the revised draft include the study design and conduct, considerations for statistical analysis, as well as recommendations on the combined evaluation of adhesion and bioequivalence.