Abstract

The present study delineates synthesis and characterization of Glipizide microspheres using tragacanth gum, inulin and HPMC as polymers for colon-specific delivery for better treatment of Type 2 Diabetes, avoiding the side effects. The Glipizide microspheres were prepared by ionotropic gelation technique by the use of various cross linking agents. The polysaccharides reacted with sodium alginate in the presence of various cross linking agents to form microspheres with a polyelectrolyte complex membrane by electrostatic interaction between the two oppositely charged polymers. The microspheres were then studied for entrapment efficiency, drug-polymer compatibility and surface morphology. In vitro drug release pattern was studied in buffer medium using USP dissolution apparatus. Further, kinetics modelling was employed to find out release mechanisms. Glipizide microspheres showed high entrapment efficiency (87.75%) and the microspheres were free flowing, non aggregated and spherical, between 500-700 μm in diameter. The FT-IR spectrum showed that there is no interaction between the polymer and drug. The in vitro release study found to be affected by using various cross linking agent. The microspheres with Barium chloride as cross linking agent showing no drug release at acidic pH but show maximum release at the end of 12th hour in simulated intestinal fluid. The rate of drug release follows koresmeyer-peppas model and zero order kinetics. It was seen from the observation data that the cumulative percentage release from all the drug loaded batches of microspheres fell within the range of 47.73% to 64.14% in 12 hours study and it was found that the % cumulative release in microspheres encapsulated with tragacanth gum was maximum for Batch GA2 (64.14%) and minimum for Batch GC3 (47.73%).The study reveals that Glipizide loaded inulin microspheres can be used effectively for colon targeting.