In vivo Evaluation of Solid dispersion of Glipizide with Low Viscosity Grade Hydroxypropyl Methylcellulose

Abstract

The aim of this study was to make and characterize Glipizide solid dispersions utilizing a low viscosity grade of hydoxypropyl methyl cellulose (HPMCLV). The phase solubility character of Glipizide in presence of various concentrations of HPMCLV in 0.1N HCl was evaluated. Glipizide solubility increases as the concentration of HPMC in 0.1N HCl was increased. Gibbs free energy (ΔGotr) values were all negative, indicating that drug solubilization occurs spontaneously. Solid dispersions of Glipizide with HPMCLV were prepared by using solvent evaporation method The physical properties of Glipizide with HPMCLV SDs were investigated using Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Dissolution studies was also performed. Subsequently, bioavailability of pure Glipizide, solid dispersion and marketed product was performed. Glipizide dissolution rate was enhanced in SDs containing HPMC, and the rate increased as the concentration of HPMC in the SDs increase. After preparing SDs and a physical mixture with HPMC, the mean dissolving time (MDT) of Glipizide decreased significantly. FTIR spectroscopy tests revealed Glipizide's stability and the absence of a well-defined Glipizide-HPMCLV interaction. The amorphous condition of Glipizide in SDs of Glipizide with HPMCLV was revealed by DSC and XRD studies. When compared to pure drug and marketed product, solid dispersion of Glipizide with HPMCLV exhibited improved bioavailability.