Development of Enteric-Coated Polysaccharide Beads Intended for Colonic Drug Delivery

Crohn's disease is a type of inflammatory bowel disease (IBD) that frequently affects the ileo-cecal region. For effective treatment, a site-targeting delivery system in the ileo-cecal region is essential. Ciprofloxacin, a broad spectrum antibiotic is widely used for the treatment of Crohn's disease. The present study is an attempt to develop enteric coated polysaccharide beads which targets the drug to the colon. Polysaccharide beads were prepared using different polymers like sodium alginate, gellan gum and chitosan by dispersing the drug loaded solution into calcium chloride and sodium tripolyphosphate solution respectively. The prepared beads were then coated with Eudragit S 100 using pan coating method. Characterization done using SEM revealed that, eudragit coated beads had uniform surface texture. Swelling study suggested that, alginate beads alone or in combination with gellan gum showed good swelling behavior in phosphate buffer (pH 7.4), whereas chitosan beads showed better swelling in pH 1.2. The drug release showed up to 10 % in acidic environment and sustained under neutral condition for a period of 10 h. Release kinetics indicated non-Fickian transport controlled by diffusion and relaxation of the polymer. In-vivo studies in rabbits indicated that the formulation was targeted to the colon region.