In Vitro Drug Release from Matrix Tablets Containing a Silicone Elastomer Latex

Abstract

A silicone elastomer latex was evaluated as a wet-granulating agent in preparing controlled release matrix tablets containing a water soluble active ingredient. A one-half fractional factorial statistical design was used to investigate the effect of five different formulation and non-formulation variables on the in vitro release characteristics of the drug from the matrix tablets. Tablets containing a high percent of fumed colloidal silica exhibited a faster drug release rate. A high drug to polymer ratio in the tablets was also shown to result in a faster release of the drug. Granules dried at a higher temperature (80°C vs. 60°C) produced tablets with a slower drug release rate. The release of the drug was shown to be pH dependent. A higher drug release rate was obtained in a dissolution medium with a lower pH (1.2 vs. 6.8).