Evaluation of Critical Quality Attributes of Dapsone Gel

Abstract

The purpose of this study was to evaluate critical quality attributes (CQAs) of dapsone gel compared to its marketed reference gel, in accordance with United States Pharmacopeia and draft guidance established by United States Food and Drug Administration, which are based on suggestions about quality and performance of the semi-solid dosage forms in recent years. In this context, pH analysis, microscopic analysis, x-ray diffraction analysis, and rheological analysis were used to evaluate quality attributes of the test products towards the reference product. In vitro release tests, in vitro permeation tests, and stratum corneum tape-stripping studies were performed to examine pharmaceutical quality and performance of the gels. In addition, stability of the test product was investigated in terms of visual appearance, pH, viscosity, quantification assay, and drug release following storage at 25 ± 2oC and 60% ± 5% relative humidity for 6 months. The quality tests indicated that the test product was similar to the reference product. The gels exhibited significantly similar diffusion coefficients and equivalent amounts in the skin layers for all products. The test product was stable for 6 months, physically and chemically. Overall, it is possible to conclude that dapsone gel is of comparable quality and performance to the marketed reference gel.