Novel Sustained Release Swellable Bioadhesive Floating Gastroretentive Drug Delivery System of Bilayer Tablets Containing Rifampicin and Isoniazid

Background: 28 different controlled release bilayer formulations of Rifamicin and Isoniaid were developed using combination of Psyllium husk Carbopol 934, Sodium carboxy methyl cellulose, Chitosan, Sodium alginate, Polymethacrylic acid ethyl acrylate and basil seed using different concentrations. Method: Initially the granules were prepared by wet granulation method and evaluated for Rifampicin granules bulk density (0.471-0.610gm/ml), tapped density (0.521-0.694gm/ml), carr’s index (8.91-15), Angle of repose (21.94?-29.74?) and for Isoniazid granules bulk density (0.474-0.594gm/ml), tapped density (0.516-0.646gm/ml), carr’s index (8.38-14.72), Angle of repose (20.08?-28.58?). Amongst 28 formulations AII and BII containing polymer psyllium husk were selected. The bilayer tablets containing 150 mg of Rifampicin and 150 mg of Isoniazid were prepared by compression one by one both layer were filled using rotary tablet machine (Table-1). Then evaluated for thickness, hardness, friability, weight variation, drug content, buoyancy lag time and duration of buoyancy, dimensional stability, in vitro dissolutions, Biomucoadhesion test, Histology study followed by floating property analysed by x-ray in the rabbit stomach using radiographic imaging technique. Conclusion: The formulation with psyllium husk is the best polymer for gastroretentive drug delivery system of bilayer tablet containing Rifampicin and Isoniazid.