PECTIN ETHYLCELLULOSE FILM COATING FORMULATIONS FOR COLONIC DRUG-DELIVERY/

Purpose, The purpose of the study was to investigate the potential of pectin, ethylcellulose combinations as a practical film coating for co lonic delivery. Methods. Combinations of pectin and ethylcellulose, in the form of an aqueous dispersion, were used as coating formulations. Paracetamol cores were used as the substrate. The coatings were asses sed by a flow through dissolution system simulating in vivo conditions by changes in pH and residence time. Pectinolytic enzymes were used t o simulate the bacterial flora of the colon. Results, Drug release was controlled by the ratio of ethylcellulose to pectin in the film coat. Increasing the proportion of ethylcellulose and increasing the coat w eight reduced drug release in pH1 and pH7.4 media. The addition of pec tinolytic enzymes to pH6 media increased the release of drug. Conclusi ons. Combinations of ethylcellulose and pectin can provide protection to a drug in the upper g.i. tract while allowing enzymatic breakdown a nd drug release in the colon.