Formulation and Evaluation of Bi Layer Tablets of Chlorzoxazone

The main objective of this research work was to formulate and evaluate the bi layer tablets of chlorzoxazone by using different polymers. Chlorzoxazone is centrally acting skeletal muscle relaxant. The tablets containing immediate releasing layer and sustained release layer. The polymers used are microcrystalline cellulose pH 102, sodium starch glycol ate, croscarmellose, povidone for immediate releasing layer, HPMC K 100 cps, K4cps, E15cps, carbomer 971P, and natural gums like guar gum, Xanthan gum for sustained drug release layer. The matrix tablets were prepared by direct compression and wet granulation methods. All the excipients are tested for compatibility with drug, which revealed that there was no physical and chemical interaction occurred. The Pre formulation parameters such as bulk density, tapped density, compressibility index and Hausner’s ratio were analyzed. The In-Vitro drug release studied were Performed in the USP dissolution apparatus- (paddle) using pH 1.2 HCL buffer and pH 6.8 phosphate buffer as dissolution media at 100rpm speed and temperature of 37oC ± 5oC. The sampling was done at periodic time intervals of 1.5, 3, 4, 6, 8, 10 and 12 hours and was replaced by equal volume of dissolution media after each withdrawal. The cumulative amount of drug release at different intervals is estimated using UV method. Based on the evaluation result the formulations F6 was selected as best formulation among immediate release and is used to compress with sustained release layer. Among all formulation FB8 formulation (HPMC K100m 88%) shown maximum release of 98.84% drug in 12th hour.