TECHNOLOGICAL EVALUATION OF 3 ENTERIC COATING POLYMERS .1. WITH AN INSOLUBLE DRUG

The enteric properties of a recent cellulose polymer, cellulose acetat e trimellitate (CAT, EASTMAN KODAK) were evaluated on an insoluble sub stract for comparison, included in this paper are the properties of tw o other cellulose esters : cellulose acetate phthalate (CAP) and hydro xypropyl methylcellulose phthalate (HP55). The physical properties and disintegration time at pH 1.2 and 6.5 were influenced by the level of coating solution. The gastroresistance was obtained more fastly with CAT and CAP than for HP55. The influence of coating solution on drug r elease from tablet was investigated. The dissolution studies were made allowing the variation of pH in the dissolution medium during the kin etics. Drug release from coated tablets was found to be dependent upon the type of polymers used to form film : higher release rates were ob tained with CAT compared to CAP and HP55.