Development and Optimization of Glipizide Nanoliposomes for Enhanced Oral Delivery

Abstract

Glipizide is a sulfonylurea drug widely prescribed for the management of type II diabetes; however, its therapeutic efficiency is limited by significant degradation in the acidic gastric environment, resulting in reduced bioavailability. To address this limitation, glipizide loaded nanoliposomes were prepared using the thin-film hydration method. A time variant optimization strategy was applied to evaluate the influence of formulation parameters, including the lecithin to cholesterol ratio, the organic to aqueous solvent ratio, and the duration of liposome formation. The optimized values for these parameters were determined to be 7:1, 4:1, and 2 hours and 20 minutes, respectively, yielding an encapsulation efficiency of 90.12%. Particle size and morphology were examined using scanning electron microscopy (SEM). The resulting nanoliposomes exhibited a uniform spherical shape with particle diameters ranging from 50 to 95 nm and a mean size of approximately 82 nm, indicating successful formation of nanoscale vesicles suitable for drug delivery applications. The nanosized structure is expected to enhance mucosal interaction and improve intestinal transport. Stability assessments performed at physiological pH (7.4) demonstrated a marked increase in the structural and chemical stability of glipizide following encapsulation. This improvement highlights the protective role of the liposomal membrane against premature degradation in the gastrointestinal environment. Overall, the findings suggest that liposomal encapsulation provides an effective strategy to enhance the stability and potential oral bioavailability of glipizide. The optimized nanocarrier system developed in this study represents a promising platform for the controlled delivery of hydrophilic antidiabetic agents and may contribute to improved therapeutic outcomes in future pharmaceutical formulations.