Influence of beta-cyclodextrin complexation on glipizide release from hydroxypropyl methylcellulose matrix tablets

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Physical Chemistry

Background:

• Glipizide exhibits poor aqueous solubility, limiting its oral bioavailability.
• Beta-cyclodextrin complexation is a strategy to enhance the solubility of poorly soluble drugs.
• Hydroxypropyl methylcellulose (HPMC) is widely used in matrix tablet formulations for controlled drug release.

Purpose of the Study:

• To enhance glipizide solubility through complexation with beta-cyclodextrin.
• To develop and optimize hydroxypropyl methylcellulose (HPMC) matrix tablets containing glipizide or its complex.
• To establish predictive mathematical models for glipizide release from HPMC matrix tablets.

Main Methods:

• Phase solubility studies were conducted to characterize glipizide-beta-cyclodextrin interactions.
• Spectroscopic and thermal analyses (FTIR, DSC, PXRD, 1H NMR) confirmed drug-excipient interactions.
• A 2(3) factorial design was employed to study the effects of polymer loads and complexation on drug release.
• Multiple linear regression and ANOVA were used to generate and validate mathematical models for drug release kinetics.

Main Results:

• The phase solubility diagram indicated an A(L) type, with a 1:1 stability constant of 413.82 M(-1) for the glipizide-beta-cyclodextrin complex.
• Significant interactions between glipizide and beta-cyclodextrin were confirmed by various analytical techniques.
• Complexation significantly affected early and sustained glipizide release (Y1, Y2, Y3), while total polymer load influenced all release parameters (Y1-Y4).
• Developed mathematical models accurately predicted drug release, with experimental data closely matching predicted values.

Conclusions:

• Complexation with beta-cyclodextrin effectively enhances glipizide solubility and modifies its release profile from HPMC matrix tablets.
• The established mathematical models provide a reliable tool for predicting and optimizing glipizide release from HPMC matrix formulations.
• This study demonstrates the successful application of factorial design and mathematical modeling for the development of improved glipizide delivery systems.