Influence of hydroxypropylmethyl cellulose and sodium carboxymethyl cellulose as coating polymers on drug release from spheroids

Abstract

The formulation of cellulose ether coated controlled-release spheroids containing chlorpheniramine maleate was described. The drug cores were prepared using a rotoprocessor and then coated with hydrophilic polymers using a bottom-spray fluidized-bed coater. Polymeric dispersion of either hydroxypropylmethyl cellulose (HPMC) or sodium carboxymethyl cellulose (NaCMC), as well as a mixture of both, were used as the coating 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) showed longer dissolution T(50%) values as compared with spheroids coated with a single polymer at the corresponding coating levels. When spheroids 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 biexponential first-order model.