Vol. 7, Issue 8 (2018)

Author(s):
Shaika Saadia Zubedi and Shahid Mohammed

Abstract:
Chlorzoxazone is a benzoxazinone derivative of BCS class II drug with mild sedative and centrally acting muscle relaxant activity. The oral delivery of muscle relaxant Chlorzoxazone tablets were facilitated by preparing floating dosage form which could increase its absorption by increasing the gastric residence time and to achieve sustainable drug release. Chlorzoxazone floating tablets were prepared by direct compression method in 8 different formulations (F1-F8) using HPMC K100 as rate retarding polymer, sodium bicarbonate and citric acid as gas generating agent. From the preformulation studies it was observed all the parameters were within limits. The prepared formulations were evaluated with pre-compression parameters like bulk density, compressibility index, hausner ratio, angle of repose and post-compression parameters like weight variation, thickness, hardness, friability, drug content, buoyancy lag time, total floating time, and in-vitro drug release. All the floating tablets possess good floating property with a total floating time for not less than 12hrs. In vitro dissolution studies of the formulations were done in pH 6.8 phosphate buffer using USP apparatus 2 (paddle method) at 50 rpm. Percent drug release of the formulations (F-1 to F-8) was from 65.34% to 99.12% after 12hrs. From the results, F-8 was selected as an optimized formulation. Kinetic studies of the optimized formulation (F8) showed that the drug release follows first order and Higuchi model which indicates drug release follows first order & diffusion mechanism. Optimized formulation (F8) was subjected to stability studies for 3 months at 25 ± 2 ^oC / 60 ± 5% RH, 30±2 ⁰C / 65±5% RHand 40 ± 2 ^oC / 75 ± 5% RH and the results were found satisfactory within limits.