In Vitro Methods to Assess Therapeutic Equivalence of Topical Products

SCOPE OF WORK In order to determine if physical testing. methods can be used to provide a measure of bioequivalence for topical dosage forms, the CPST proposes to condm:t the following activities: 1} Manufacture topical products by two methods as prescribed by the FDA . Products may include gels, lotions, creams or ointments . Master Batch Records will be generated, reviewed and approved for each batch 2) Characterize the manufactured products (or products supplied by the FDA) using the following parameters: . Rheology -Brookfield Programmable Cone and Plate Rheometer . viscosity as a function of shear rate . linear viscoelasticity . yieldstress -measurements as a function of time . Particle Size Characterization -Coulter N4 Plus Sub-Micron Particle Sizer . Sizing sub-micron (1-3000 nm) particles -Beckman Coulter 22 Particle Counter . Sizing micron (1- 120 micron) particles . Appearance -Visual and Microscopic . Content Uniformity -Analytical method to be supplied by FDA . Diffusion through an artificial membrane -Franz Diffusion Apparatus . Diffusion of radiolabel markers through formulations -Dual Label Scintigraphic imaging . Release rate of drug from the formulations -Diffusion Chambers The results of these measurements will be compared for formulations that are Ql/Q2 similar but were manufactured by different methods.