STUDIES ON DRUG-RELEASE FROM PECTIN ETHYLCELLULOSE FILM-COATED TABLETS - A POTENTIAL COLONIC DELIVERY SYSTEM/

Combinations of pectin and ethylcellulose, when applied as a film coat , have potential value as a colonic delivery system. Aqueous dispersio ns of pectin and ethylcellulose were used to film coal paracetamol tab let cores. Drug release mechanisms were assessed using flow through di ssolution testing in the presence and absence of enzymes. Drug release from the coated systems was complex and depended on the nature and ch aracteristics of the mixed film as well as the composition of the diss olution medium. Drug release profiles were compatible with a mechanism involving the formation of channels in the film caused by pectin diss olution. Channel formation was in most cases accelerated by the presen ce of pectinolytic enzymes showing that the pectin in the mixed film w as susceptible to enzymic attack. Pectin, ethylcellulose combinations may have value as film coating preparations for colonic delivery. Form ulation effects and mechanisms of drug release have been identified as a basis for further studies. (C) 1997 Elsevier Science B.V.