Glipizide is an oral blood glucose lowering agent having short biological half life (2-4 hrs). Since oral sustained release dosage form of this drug is less frequently available worldwide, therefore the present study was conducted to develop formulation of glipizide using ethyl cellulose (hydrophobic), high viscosity grades of hydroxypropyl methylcellulose (hydrophilic) and Kollicoat SR (hydrophobic-hydrophilic mixed). All the polymers were incorporated separately in the matrix system using wet granulation technique. In vitro dissolution studies were conducted in 450 ml 0.1M NaOH solution for 12 hrs testing intervals. Dissolution data indicated that as the amount of various polymers increased, the release rate of glipizide form matrix tablet was decreased. However, more sustaining effect was produced by HPMC based matrix tablets compared to EC or Kollicoat SR-based matrix tablets. However, HPMC-based formulation comprising 10% glipizide, 50% HPMC, 39% lactose, and 1.0% magnesium stearate produced more linear release profile and comparable to reference product, Glipizide XL.
Keywords: Glipizide, HPMC, Polyvinyl acetate, Kollicoat SR, Sustained release