GLIBENCLAMIDE SOLUBILITY ENHANCEMENT BY MODIFIED NATURAL CARRIERS USING THE SOLID DISPERSION TECHNIQUE

The present study was undertaken to explore the potential of natural carriers such as locust bean gum and guar gum for dissolution enhancement of glibenclamide. The locust bean gum and guar gum were modified by heating at 120 degrees C for 2h. Solid dispersions were prepared by the solvent evaporation method using modified gums individually at 1:2, 1:4, 1:6, 1:8, 1:10 and 1:12 drug to carrier ratio. The prepared solid dispersions were evaluated for equilibrium solubility studies, content uniformity, in vitro dissolution testing, thermal analysis and in vivo studies. The solubility studies showed an increase in the solubility of glibenclamide with the increase in the concentration of carriers but it was up to 1:8 and 1:10 in the case of modified locust bean gum and modified guar gum respectively. All the batches lie within limits for content uniformity according to the United States Pharmacopeia (USP). The decrease in peak intensity and a slight shift in peak of drug in differential scanning calorimetry (DSC) thermograms of solid dispersions batches indicated a slight conversion of crystalline to amorphous form. Fourier Transform Infrared Spectroscopy (FTIR) studies indicated no interaction between drug and carriers, which was further confirmed by X-Ray diffraction (X-RD) studies. The dissolution rate of glibenclamide from solid dispersions was maximum in L4 and 05 batches with a cumulative release of 96.17% and 96.78% in 2h respectively. In vivo results showed a superior activity of L4, 05 as compared to plain glibenclamide in alloxan-induced diabetic rat model.