Development of Polyelectrolyte Complex Beads Containing Vancomycin Hydrochloride for Colon-targeted Drug Delivery

Abstract

: Vancomycin Hydrochloride is a glycopeptide antibiotic used for the treatment of Pseudomembranous colitis. This drug is susceptible to proteolytic degradation in the gastric environment and it is associated with nephrotoxicity. As the therapeutic action of vancomycin hydrochloride is intended in the intestine, colon-targeted drug delivery could help the drug achieve sufficient concentration in the target site. A polyelectrolyte complex using chitosan and hupu gum is used to prepare the beads that control the drug release and minimize the adverse effects. Eudragit S100 is used as an enteric coating material to bypass the gastric environment. The beads thus formed by polyelectrolyte complex were filled into capsules and coated with Eudragit S100. The formulation (CHP3C8) containing chitosan and hupu gum with polyethylene glycol 400 and 8% Eudragit S100 coating has shown a controlled drug release of up to 24 hours with a predetermined lag time. The ex-vivo studies have shown higher drug release in rat cecal content which can be attributed to the degradation of polyelectrolyte complex by intestinal bacteria. The in-vivo studies are carried out using white New Zealand rabbits where the capsules (CHP3C8) and solution of pure drug of vancomycin hydrochloride are administered via the oral route. The peak plasma concentration (C max ) of Vancomycin Hydrochloride from CHP3C8 and the oral solution was found to be 809.53 µ g/ml and 402 µ g/ml respectively. All the results have shown the superiority of Vancomycin Hydrochloride polyelectrolyte beads (CHP3C8) over the pure drug indicating its suitability for colon drug delivery.