STUDIES ON MICROBIALLY TRIGGERED ENTERIC COATED TABLETS FOR COLON TARGETED DELIVERY OF MESALAMINE

Objective: This study aims to develop an enteric coated (coated with Eudragit S-100) matrix tablet of Mesalamine to improve the bioavailability by targeting the drug to the colon for the treatment of ulcerative colitis. Materials and Methods: Matrix tablets were prepared by wet granulation technique by applying 3² full factorial designs for optimization. The independent variables used were the amount of guar gum, and amount of starch paste, each at three different levels and dependent variables was hardness, percent cumulative drug release (% CDR) study at 5^th hr. and time required for 90% of drug release (t_90%). The prepared matrix tablets were coated with Eudragit S-100. Result and Discussion: The prepared tablets were characterized for physical parameters, in-vitro drug release (with and without 2% rat ceacal contents) and stability on storage. The optimized formulation was subjected to in-vivo roentgen graphic studies to analyze the in-vivo behavior of the prepared tablet. The optimized formulation consisting of guar gum (20% w/w) and starch paste (15% w/w) released a negligible amount of drug at pH 1.2 and pH 7.4 whereas the maximum amount of drug release was observed at pH 6.8 in the presence of 2% rat caecal contents. The in-vitro drug release of marketed formulation (Mesacol) also studied, the results show that formulation was unable to target drug in the colonic region when compared with the optimized formulation. Conclusion: The enteric coated guar gum based matrix tablets of Mesalamine is a potential system to target the drug release in the colon for better treatment of ulcerative colitis.