Formulation and In-vitro Evaluation of Compression Coated Tablet of Tinidazole for Colon Spe-cific Drug Delivery System

Compression coating is one of the strategies for delivering drug to the colon based on gastrointestinal pH & transit time concept. The aim of the present study is to formulate colon targeted drug delivery of Tinidazole compression coated tablets by using different ratios of Chitosan and Pectin. Compression coated tablets have been coated with carbapol 934P which enables drug release at the pH of colonic fluid. Core tablets of Tinidazole (300 mg) were prepared by using swellable and pH Dependent polymers like chitosan and pectin in which PVP-K30 was used as Binder. Drug release profile was evaluated in simulated gastric fluid, intestinal fluid and simulated colonic fluid. The drug release studies were performed according to the USP paddle method by using 0.1N HCl for 2hours, pH 7.4 phosphate buffers for 3 hours and pH 6.8 phosphate buffers up to 24 hours without using rat caecal content. Compression coated tablets containing chitosan as polymer released 95- 99% of Tinidazole in simulated colonic fluid, whereas tablets containing pectin as polymer released 94-99% of Tinidazole. The stability study for prepared tablets at 40°C and 75% relative humidity for 6 weeks showed no significant change in physical appearance, drug content uniformity and in vitro drug release pattern. From the result it can be concluded that formulation F3 (Chitosan compression coated tablets) and formulation F5 (Pectin compression coated tablets) were suitable for colonic drug delivery as drug release was found to be maximum when compared to other formulations