Pharmaceutical Design and in vitro Evaluation of Sustained release

The objective of this study is to design and evaluate sustained release tablets of Carbamazepine (CZP).The effects of various viscosity grades of Methocel(Methocel K4M, Methocel K100M and combination of both) on the release of Carbamazepine have been evaluated. Tablets were evaluated for physical and chemical parameters such as Hardness, Friability, Thickness, Weight variation, Drug content uniformity and in vitro release. All batches are complied physical and chemical parameters within the U.S.P limit. The amount of Carbamazepine at different time intervals were estimated by HPLC method. In vitro release profile of Carbamazepine from combination of both Methocel K4M and Methocel K100M polymers (F10) showed that 90% of the drug was released at the end of 12 hr which is considered as optimized formulation. The release profile of formulation F10 has achieved the optimum U.S.P limit when compared to marketed formulation. The tablets showed no significant change either in physical appearance or in dissolution pattern after storing at 4c, 40 c / 75% RH and 60c / 80% RH for three months. The TG/DTA study revealed that there is a weak intermolecular interaction occurs between drug and excipients. The drug release data fit well to Higuchi, Peppas and Korsemeyer equation. The drug release was found to have swelling, diffusion and little extent by erosion.