Preparation and characterization of gliclazide-polyethylene glycol 4000 solid dispersions

The objective of the present investigation was to study the effect of polyethylene glycol 4000 (PEG 4000) on in vitro dissolution of gliclazide from solid dispersions. Initial studies were carried out using physical mixtures of the drug and carrier. Solid dispersions were prepared by the melting or fusion method.Phase and saturation solubility study, in vitro dissolution of pure drug, physical mixtures and solid dispersions were carried out. PEG was found to be effective in increasing the dissolution of gliclazide in solid dispersions when compared to pure drug. FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry studies were carried out in order to characterize the drug in the physical mixtures and solid dispersions. Dissolution enhancement was attributed to decreased crystallinity of the drug and to the wetting and solubilizing effect of the carrier from the solid dispersions of gliclazide. In conclusion, dissolution of gliclazide can be enhanced by the use of hydrophilic carrier.