Transdermal and Topical Adhesion Assessment Guidance
FDA has issued a draft guidance, Assessment of Adhesion for Topical and Transdermal Systems Submitted in New Drug Applications, with recommendations for clinical trials designed to assess the adhesion performance of transdermal and topical delivery systems. The document says adhesion performance can affect both safety and effectiveness of transdermal and topical delivery systems because adhesion failures can result in reduced effectiveness caused by suboptimal dosing or potentially increased exposure when a new system needs to be applied sooner than the scheduled dose.
Also, the guidance says, partial or full detachment of a system from a patient’s skin may result in unintentional exposure of the active pharmaceutical ingredient to a partner, child, or other individual, potentially exposing them to the drug’s toxicity.
The guidance recommendations relate to studies to be submitted in support of a NDA or sNDA for human prescription and nonprescription drug products. FDA says biological products are outside its scope because they are often more complex and of a higher molecular weight, making it likely they would not be absorbed across the skin, requiring a different approach for administration.