Impact of Granulation and Effect of Polymers on Theophylline Release from Matrix Tablets

The effects of plastic, hydrophilic and hydrophobic types of polymers and impact of granulation process were investigated on the release profile of theophylline from matrix systems. A comparative release characteristics were evaluated by the use of polymers from different theophylline matrices. Matrix tablets of theophylline using Methocel K4M, Ethocel 20 cps, Kollidon SR were prepared separately by direct compression and moist granulation process. In this investigation the feasibility of moist granulation technique in the development of sustained release matrix tablet of theophylline was studied. The kinetics of the dissolution process was determined by analyzing the dissolution data using various kinetic equations, e.g. zero-order, Higuchi and Korsmeyer equations. The mean dissolution time (MDT) was calculated for all the formulations. The analysis of the dissolution data showed that the release process involves erosion and diffusion. Drug release was different from different classes of polymeric matrices and from tablets prepared by different manufacturing processes. The results showed that the profile and kinetics of drug release were the functions of polymer type, polymer content and granulation process. Key words : Theophylline, Moist granulation, Direct compression, Methocel K4M, Ethocel 20 cps, Kollidon SR doi: 10.3329/dujps.v7i2.2168 Dhaka Univ. J. Pharm. Sci. 7 (2): 133-139, 2008 (December)