Cyclodextrin complex osmotic tablet for glipizide delivery.

Poorly soluble glipizide was selected as the model drug to prepare osmotic pump tablets (OPT) with proper accessorial material after it was made an inclusion complex by kneading method in order to increase solubility. Polyethylene glycol 4000 (PEG4000) and cellulose acetate (CA) were selected as the coating materials, and acetone-water (95:5) co-solvent was employed as the coating medium. The effects of the osmotic promoting agent, diameter of the drug-releasing orifice, coating composition, and coat weight on the drug release profile were investigated. The drug release profile of the optimal formulation was compared with a commercialized push-pull osmotic tablet. The results indicated that glipizide-cyclodextrin inclusion complex OPT had excellent zero-order release characteristics in vitro.