How Modeling Was Used to Support the FDA Approval of a Topical Generic Drug Product

Establishing bioequivalence for topical drug products can be challenging and costly, often requiring extensive comparative clinical endpoint studies that may not effectively capture formulation differences. However, the FDA’s recent approval of a generic diclofenac sodium topical gel, 1%, demonstrates how physiologically based pharmacokinetic (PBPK) modeling can provide an innovative alternative by supporting bioequivalence assessments without the need for these traditional studies. This approach not only validated the product’s equivalence to the reference drug but also showcased the potential of novel quantitative tools to enhance the development and approval processes for generic topical drug products.