EVALUATION OF FLUID-BED APPLIED ACRYLIC POLYMERS FOR THE TARGETED PERORAL DELIVERY OF INSULIN

Fluid-bed applied acrylic polymers were used to develop a targeted del ivery system for human insulin. A multiparticulate system, in which an inert substrate was coated with drug and a combination of enteric (Eu dragit L30D) and time release (Eudragit RL30D, RS30D) polymers was for mulated for delivery of insulin to the ileum. A full factorial design was implemented to evaluate the effects of fluid bed processing condit ions on drug release. Using optimum processing conditions, a central c omposite design was used to investigate the effects of polymer concent ration and ratio of the time-release polymers on drug release. Utilizi ng a partial cubic response model, a concentration of 10% w/w and a ra tio of 2/3 Eudragit RL30D/RS30D was found to give the desired release rate. Based on the above studies, four dosage forms containing insulin were prepared and evaluated in vivo utilizing Sprague-Dawley mts as t he animal model. Results indicate the delivery system containing enter ic coating only in conjunction with enzyme inhibitor and absorption en hancer provided a significant improvement in drug bioavailability.