DEVELOPMENT AND CHARACTERIZATION OF A MINI CAPSULAR EXTRUSION SYSTEM FOR ENTERIC DELIVERY OF METRONIDAZOLE BEARING LIPOSOMES

A capsular extrusion system was developed for enteric delivery of metr onidazole loaded liposomes. The system is essentially based on a minio smotic pump except that the extrusion in the present system is brought about by the swelling of a swellable polymer which raises the vestibu le and extrudes out the contents through a delivery orifice. Drug rese rvoir of the system contained freeze dried liposomes which become hydr ated prior to extrusion. Extruded liposomes were uniform in size with 45-68% incorporation of metronidazole. When tested for in vitro antiam oebic and antibacterial activity it was found that the effectiveness o f liposomal metronidazole was significantly higher as compared to the unformulated drug.