Colon Delivery of Budesonide Using Solid Dispersion in Dextran for the Treatment and Secondary Prevention of Ulcerative Colitis in Rat

OBJECTIVES: Ulcerative colitis is characterized by local inflammation. Targeting drugs directly to the site of injury has the benefit of lower adverse effects and more effective therapy. The aim of this study was colon targeted delivery of budesonide to deliver the major part of the drug to the colon. METHODS: Matrix tablets of budesonide from solid dispersion of drug with dextran were prepared using different drug to polymer ratios and three molecular weights of dextran. The physical evaluation and drug release behavior were studied. In vivo efficacy of the selected formulation against acetic acid induced colitis in rats was evaluated and compared to the control (untreated) and references (mesalazine and budesonide suspensions) groups. RESULTS: The results showed that solid dispersion of budesonide with dextran in the ratio of 1:7 using molecular weight (MW) of 10,000 dextran (SDT710) released 25% of the drug in the first 6 hours and 100% in caecal and colonic contents. It could target the drug to colon with improvement in some of the inflammatory signs of induced ulcerative colitis in rat. Treatment with SDT710 could improve not only the percent of involvement also macroscopic damage parameters. The macroscopic parameters included weight/length ratio of the colon, ulcer area, damage score, and ulcer index reduced in comparison to the control group and conventional suspension of budesonide; however, only weight/length ratio was significant. CONCLUSIONS: In the experimental model studied, the new colonic delivery system significantly improved the efficacy of budesonide in the weight/length ratio of the colon in induced colitis in rats.