Development of an In Vitro Release Test (IVRT) for a Vaginal Microbicide Gel

Abstract

Sensitive and reproducible methods to assess in vitro release rates from semisolid products can provide significant value during drug development. The purpose of the present study was to develop and validate an in vitro release test (IVRT) for a topical gel formulation of an HIV microbicide. The method was developed using a vertical diffusion cell system, commercially available synthetic membranes, and HPLC with UV detection. The IVRT method was robust, reproducible, and sensitive to some of the formulation parameters evaluated. The method was applied to evaluate release rates of the active pharmaceutical ingredient from formulations during stability studies.

Comparison of In Vitro Release Rates of Diclofenac Topical Formulations Using an In-Line Cell Automated Diffusion System

“…Furthermore, other advantages include setting regulatory specifications for the products for quality control purposes to ensure the impact of excipients on product performance, evaluation of potential dosage variations, and monitoring lot-to-lot consistency to ensure product sameness. Compared to other quality control tests like assay, homogeneity, rheological properties, specific gravity, and particle size determination, IVRT provides more information regarding the release properties for topical formulations; however, the test is not a measurement of or predictive for bioavailability (2).…”

“…However, for products formulated with waterinsoluble drugs, the selection of an appropriate receptor solution to maintain sink conditions is a challenge. It may be necessary to alter receptor fluid pH, add surfactants and/or complex agents, or use organic media in which the drug is more soluble to efficiently dissolve the active pharmaceutical ingredient (API) during release studies (2,9).…”

Development of Analytical Method for In Vitro Release Testing of Dexamethasone Nanosuspensions

“…IVRT methods should be reproducible and sensitive to small changes in physicochemical properties of the dosage form (5). Development of IVRT tests for the nanosuspension delivery systems is especially challenging due to difficulties with sample filtration and/or separation.…”