Determination of Microstructural Impact on the Release of Drug from Hydroxypropyl Cellulose Gel by Validated In Vitro Release Test Method.

Abstract

Microstructure of a semisolid system is greatly influenced by the formulation composition and the processing parameters. Different polymers exhibit different three-dimensional structure and these have a great impact on the drug release properties. The current research focuses on studying the impact of hydroxypropyl cellulose gel microstructure on the release properties of chlorhexidine gluconate (CHX G). The two main investigating methods of microstructure were used namely, rheology and texture analysis to determine the differences in the formulations studied. The CHX G drug release study was performed using a developed and validated in vitro release test method, which is reproducible, discriminative, and robust to detect the formulation differences. The drug release results showed that there was appreciable difference in the release rates of the different formulations. The rheology and texture analysis data correlated well with the difference in the release rates. The formulations differences were further confirmed by a statistical approach using analysis of variance.