Sustained-release dosage forms containing chlorpheniramine maleate with water-insoluble glucan.

Abstract

In order to investigate the pharmaceutical availability of the water-insoluble glucan produced by Streptococcus mutans, application of the glucan as a filler for sustained-release tablets was studied. Glucan alone or the combined powder of glucan with lactose was used as a filler for these tablets and chlorpheniramine maleate (CPM), a potent antihistaminic, was used as a medicament. When the concentration of glucan was higher than 60%, directly compressed tablets were very hard and scarcely disintegrated. The release of CPM from a single face of the tablets was linear when plotted as a function of the square root of time. The release rate of CPM increased with a decrease of the concentration of glucan. The amount of CPM release increased in proportion to the initial concentration of CPM when the amount of CPM in the tablet was less than 25 mg. The effects of the tablet weight, the compressional pressure and the concentrations of glucan and CPM on the drug release rate from the whole tablets were also studied. The release profile of the tablet containing glucan was compared with that of a commercial tablet containing the same active ingredient. In the case of the tablet containing glucan, in contrast to the commercial tablet, no gap was observed in the release profile when the dissolution medium was changed from No. 1 to No. 2 disintegration media in JPX [Japanese Pharmacopeia]. The water-insoluble glucan may be useful as a filler for directly compressed sustained-release tablets.