Studies On 5-Aminosalicylic Acid Tablets For Colon-targeted Drug Delivery And Its Pharmacodynamics And Elementary Pharmacokinetics Investigation

Colon, as a site offers distinct advantages on account of a near neutral pH, a much longer transit time, reduced digestive enzymatic activity and a much greater responsiveness to absorption enhancers. This enables the visualization of this distal part of GIT as a site for delivery of various drug molecules including proteins and peptides. Bacterially triggered colon specific drug delivery system (BCDDS) is using the existing of micro flora to preparation oral colon-specific drug delivery system OCDDS. For local pathologies of colon specific drug deliver, not only increase the bioavailability of drug at the target site, reduce the dose to be administered but also would reduce the side effects.5-aminosalicylic acid (5-ASA) is an important drug treating IBD, including Ulcerative Colon and Crohn's Disease. The major side effect is the stimulation to stomach and small intestine. The active form of 5-ASA to treat IBD is its original shape. But the absorption in the upper GIT will bring the side effect and deactivate the 5-ASA. Several OCDDSs have been coming into the market in the overseas, however they all have the disadvantage that a substantial amount of drug may be released in the small intestine before the delivery system arrives in the colon. There have no domestic 5-ASA preparation came into market. So the study on the 5-ASA colon specific delivery system is of great significance.In this article we use the new colon digested material chitosan film as a coat to protect 5-ASA tablet from the releasing in the small intestine and the Eudragit L100-55 as the enteric coat, meanwhile study the pharmacodynamics and the release profiles of 5-ASA in vitro and in vivo.MicroCellulosePH101 ( filling agent ) PVPP(disintegration agent) PVP K30(binding agent)have been mixed, wet-grained and prepared into tablets. The disintegration time was used as the index to evaluate the factors and Rx. The results showed that the best Rx is the pvpp5% 10%pvp50%ethanol/H2O talcum powder 5% and the disintegration time is 197s.