Abstract

Objective: The aim of the present study is to develop floating microspheres of Glipizide, an oral rapid- and short-acting anti-diabetic drug from the sulfonylurea class. Glipizide is rapidly and completely absorbed from the gastrointestinal tract. Single unit dosage form of Glipizide causes gastric irritation and when converted to multiple unit dosage like microspheres causes no gastric irritation and maintains a constant drug concentration in the blood plasma for a longer period of time as glipizide is rapidly absorbed and eliminated from the body. Methods: Preformulation studies like identification tests, solubility analysis, melting point determination, compatibility studies and evaluation of formulation blend are determined by suitable methods. Floating microspheres of Glipizide were prepared by ‘emulsion solvent evaporation technique’by employing polymers like ethylcellulose, HPMC K4M, HPMC K15M and solvents like ethanol, dichloromethane and tween80. Floating microspheres are evaluated for drug entrapment efficiency, particle size by microscopic method, shape and surface morphology by scanning electron microscopy, in vitro drug release studies. Results: The floating microspheres were evaluated for angle of repose, particle size, percentage yield, in vitro buoyancy, incorporation efficiency, drug polymer compatibility (IR study), scanning electron microscopy, drug release and DSC(Differential Scanning colorimetry), of microspheres. Results show that as the concentration of polymer increases, the particle size, percentage yield, in vitro buoyancy and drug release from microspheres varies. Percentage drug release at the end of 12 hrs was found to be 91%. Microspheres that are prepared by HPMC K15M exhibited excellent Micromeritic properties, percentage yield, in vitro buoyancy, incorporation efficiency and percentage drug release when compared to HPMC K4M and Ethyl Cellulose polymer. Conclusion: Results clearly indicate that floating microspheres of Glipizide offers a suitable, practical approach to achieve a prolonged gastric residence time and continuous release of the medication over an extended period of time thus oral bioavailability of the drug and subsequent efficacy is improved.

Authors and Affiliations