In-vitro Drug Release Studies of 5-Fluorouracil from Novel Enteric CoatedCapsules Utilizing Combined Approaches of pH-dependent and microbialtriggered biodegradable polysaccharides for Colon Specific Delivery

摘要

The objective of present study is to design a novel enteric-coated colon targeting drug delivery system of 5-fluorouracil (5-FU) using biodegradable guar gum as a carrier for colorectal cancer treatment. Formulation matrix containing 30% guar gum was prepared and coating was done using polymers of hydroxyl propyl methyl cellulose (HPMC) for inner hydrophilic coating and Eudragit??L/S-100 for outer enteric coating in different ratio (2:4, 3:2, 3:4 and 4:3). The prepared formulations were subjected to in-vitro drug release studies in various simulated gastric and intestinal fluids, were found gastro resistant for 2 h at pH 1.2 and further 3 hr at pH 7.4, since they released only less than 10% of drug. Furthermore, the release studies was carried out in absence (control) and presence of simulated colonic fluid media containing 2 and 4% w/v rat caecal content. The results obtained after enzyme induction for the period of 2, 4 and 6 days revealed significant release profile compared to control at the end of 24 h studies. Further, report suggested that guar gum was biodegradable and susceptible to the colonic microfloras under anaerobic environments. Scanning electron microscope (SEM) report of surface coated formulations illustrated that HPMC provided rough surface for good adhesion to enteric Eudragit??L/S-100 films over the plain gelatin. DSC thermogram showed no possibilities of interferences between drug and polymers used during formulation development. Therefore, it can be concluded that guar gum is a promising potential carrier for targeting 5-FU in the vicinity of colon in order to treat colon cancer effectively.