Formulation and Evaluation of Extended Release Tablet of Divalproex : Extended Release Tablet of Divalproex Sodium

The present study was aimed to develop an extended release matrix tablet of Divalproex sodium using hydrophilic polymer as release retarding agent. The formulation of Divalproex sodium matrix forming tablet was developed by using 2 factor 3 level full factorial design. The concentrations of HPMC K100M (10%, 12.5% & 15%), Eudragit L100 (10%, 12.5% & 15%) were selected as independent variables. The dependent variables selected were %drug released at 3hr, and %drug released at 12hr. As the drug has good flow property and compressibility, the direct compression method was employed to formulate the tablets. Tablets were evaluated for various physicochemical parameters. In vitro drug release study showed that batch F8 (HPMC K100M-15%, Eudragit L100-10%) was found to be optimized as it had almost identical dissolution profile with marketed product. Eudragit show synergism with HPMC K100M on drug release retardation and avoid the chances of burst release. The kinetic release treatment showed that Korsmeyer equation has shown of r2 = 0.988. Stability study of optimized batch F8 was conducted at accelerated conditions for one month and it was found to be stable.