METRONIDAZOLE LOADED EUDRAGIT COATED ALGINATE BEADS FOR COLON TARGETING

The aim of present study was to investigate the possible application of Eudragit S®-100 coated alginate beads as a controlled release system of low molecular drugs with high solubility. Metronidazole has used as a model substance. The beads were prepared by the ionotropic gelation method and the effect of various factors (alginate, drug and calcium chloride concentrations) on bead properties was investigated. The addition of drug and alginate increased the drug loading capacity of the beads, thus larger beads were obtained. On the other hand, addition of calcium chloride retarded the drug release from beads. The erosion of the beads was suppressed by Eudragit coating. Coating of Eudragit on alginate beads exhibited no drug release at acidic pH, however continuous release of drug was observed from the formulation at colonic pH. It is concluded that Eudragit coated alginate beads may be used as a potential site specific release system of metronidazole.