ABSTRACT:

Many researchers focused search light on importance of colon specific drug delivery system. These systems proved their efficacy and feasibility to treat various life threatening diseases of colon. The aim of present investigation was to develop more feasible and site specific colon targeted drug delivery system for better patient compliance. In present study the core minitab were designed by using direct compression technique and further coated with different pH dependent polymers like HPMC, Eudragit E-100 and Eudragit L-100 by using pan coating technique. The Ornidazole was used to design colon specific drug delivery system. The dissolution studies were performed at different pH levels in USP dissolution-II apparatus. The core minitab were designed by using drug, citric acid and various additives and evaluated for physicochemical parameters and In-Vitro dissolution study. The core minitabs of Ornidazole showed adequate drug release. The developed core minitabs further coated and evaluated for In-Vitro drug release study and various physicochemical parameters. The optimized formulation consists coating level of HPMC layer was 4%, Eudragit E-100 layer was 12 %, HPMC layer was 2% and Eudragit L-100 layer was 10% respectively. In-Vitro dissolution studies showed that developed system has six hours of lag phase. The enteric coating gives protection up to two hours in acidic condition, Acid soluble coat protects system up to four hours in small intestinal condition. As system switched to pH 7.4 after six hours triggered the release of drug due to solubilization of acid soluble coat by citric acid. In present investigation, Eudragit E-100 is an acid soluble polymer and solubilization of the acid soluble coat is triggered by citric acid. In-Vitro drug release of Ornidazole was markedly found faster when citric acid was included in core minitab.