Development of a robust once-a-day glipizide matrix system.J Pharm Pharmacol. 2007 Jun; 59(6):769-75.JP
The robustness of a new hydroxypropylmethylcellulose (HPMC) based modified release glipizide (10 mg) formulation was studied. The tablet formulations were prepared by dry blending the ingredients and direct compression, incorporating a range of release modifying agents up to +/-20% w/w relative to an optimized formulation. The dissolution was assessed in 900 mL pH 6.8 buffer at 75 rev min(-1) paddle speed. Calculated difference and similarity factors (f(1) and f(2)) and results of analysis of variance suggest that the overall release profiles were similar. Compositional changes up to +/-20% w/w and a reduction of drug dose to half did not change the general release pattern of this low dose/pH-dependent drug in a significant way. It is concluded that the drug release from the developed matrix systems is highly dependent on the kinetics of hydration and erosion, and that the proposed compositional changes within +/-20% w/w did not alter this relationship. The particulate systems used were characterized by determining the Carr index, Hausner ratio and the rheological properties using a texture analyser. Results indicate that the release is reproducible and the system has potential for successful scale-up operation, while complying with recommended Food and Drug Administration guidelines "Scale Up and Post Approval Changes".