Evaluation of chlorpheniramine maleate sustained release formulations

Calcium alginate beads of chlorpheniramine maleate [CPM] were prepared and the drug release was studied at different pHs. The bioavailability of CPM from CPM-calcium alginate beads was assessed in rabbits and compared with that from dry adsorbed emulsion previously prepared. DSC and IR studies showed that the drug formed a complex with alginate molecules. Generally, the drug release was faster in alkaline pH [7.4] than in acidic pH [1.2]. The study revealed that CPM-beads were better than CPM-dry adsorbed emulsion as a sustained release formulation. The extent of bioavailability of CPM-beads showed, on equal dose basis, an equivalent therapeutic effect to one dose of regular release CPM