Lead Scientist U.S. Food and Drug Administration Silver Spring, Maryland
Presentation Description: This presentation will summarize (for the first time) a series of coordinated FDA-funded research studies to develop new approaches to evaluate bioequivalence (BE) for topical generics. These studies characterized solution, gel, ointment, lotion and cream topical products containing a range of drugs including acyclovir, metronidazole, nystatin, triamcinolone acetonide, lidocaine, prilocaine, and diclofenac. Frequently, BE assessments with the same set of products were conducted in vitro and in vivo, under matched conditions. In vitro studies included physical and structural (Q3) product characterizations as well as in vitro release (IVRT) and in vitro permeation test (IVPT) studies. In vivo BE studies utilized pharmacokinetic endpoints (e.g., dermal microdialysis) or clinical endpoints. Collectively, these studies have established a remarkably clear, consistent, and substantial body of evidence supporting the utility of sensitive and efficient in vitro BE methods for topical products as an alternative to (or in support of) an in vivo BE assessment.
Describe the criteria that should be satisfied for a complex generic topical product to be considered bioequivalent and therapeutically equivalent to a brand name reference product.
Explain why it was historically challenging to develop topical generics and discuss the relationship between the limited availability of topical generics and extraordinary increases in prices for topical products.
Appraise the comprehensive body of evidence indicating that in vitro methods are sensitive and discriminating, and that they can correlate with and be predictive of in vivo bioequivalence.