Gastrointestinal Mucoadhesive Patch System for Oral Administration of Metronidazole

  Advancement in science and technology has leds to an evolution of controlled drug delivery as one of the important facets of novel drug delivery with an aim of designing therapeutically efficient dosage forms.  With this insight an attempt was made in designing an oral patch system developed with an inspiration to mimic transdermal drug delivery system. The hypothesis involved development of a compressed patch system for achieving steady therapeutic levels of a model antiprotozoal antibiotic Metronidazole. The patch system comprises of a poorly permeable layer, a mucoadhesive layer containing drug-loaded microspheres and a backing layer. The drug content of microspheres was found to be 50% with an average particle size of 100m. Individual layers of patch system were evaluated for folding endurance, flexibility, thickness and mucoadhesion test. Finally compressed patch system was folded and encapsulated into hard gelatin capsule, then subjected for in-vitro dissolution test in phosphate buffer and also for in-vitro diffusion across cellophane membrane and rat intestine. Drug-excipient compatibility studies revealed no interaction. The stability data further assured the stability of formulations. Thus formulations seem to match mostly gastro retentive category of sustained release forms through bio-adhesion approach concluding an easier, controlled and safer means of oral administration. Key words: Mucoadhesion, compressed patch system, gastro retentive device.