Influence of Formulation and Other Factors on the Release of Chlorpheniramine Mateate from Polymer Coated Beads

Abstract
Controlled release beads containing chlorpheniramine maleate, coated with Eudragit RL and RS, were prepared using the Wurster process. The effect of membrane thickness, polymer ratio of the coating material, agitation speed and pH of the dissolution medium on drug release were investigated using the USP dissolution basket method. The in vitro release of drug was described adequately by a previously published equation. The release rate constant (K) was dependent on the membrane thickness, the polymer ratio and pH of the dissolution medium. On the other hand, agitation speed used in this study did not have any influence on the release of the drug.