INFLUENCE OF HYDROXYPROPYLMETHYL CELLULOSE AND SODIUM CARBOXYMETHYL CELLULOSE AS COATING POLYMERS ON DRUG-RELEASE FROM SPHEROIDS

The formulation of cellulose ether coated controlled-release spheroids containing chlorpheniramine maleate was described. The drug cores wer e prepared using a rotoprocessor and then coated with hydrophilic poly mers using a bottom-spray fluidized-bed coater. Polymeric dispersion o f either hydroxypropylmethyl cellulose (HPMC) or sodium carboxymethyl cellulose (NaCMC), as well as a mixture of both, were used as the coat ing solutions. Drug release from spheroids coated with single polymer of HPMC or NaCMC was reduced with an increase in coating levels. Drug release from spheroids coated with a mixture of HPMC and NaCMC (1/1) s howed longer dissolution T-50% values as compared with spheroids coate d with a single polymer at the corresponding coating levels. When sphe roids were coated with two polymers, HPMC and NaCMC, one following the other, the relative position of the polymer governs the drug release profile. All the release kinetics exhibited a bi-exponential first-ord er model.