FORMULATION AND EVALUATION OF SOLID DISPERSION OF GLIPIZIDE FOR SOLUBILITY AND DISSOLUTION RATE ENHANCEMENT

Abstract

The poor solubility of drug substances in water and their low dissolution rate in aqueous G.I.T fluid often leads to
insufficient bioavailability. Glipizide is a class-II antidiabetic drug which is purely insoluble in water. Since only
dissolved drug can pass the gastro intestinal membrane, proper solubility of the drug is ultimately desired. Solubility of
the poorly soluble drug, glipizide, is enhanced by formulating solid dispersion using melting fusion and solvent
evaporation method. Drug and carriers like Eudragit E-100, Croscarmellose and Sodium Starch Glycolate in different
ratios like 1: 1, 1: 2, 1: 3 and 1:4 were used for formulating solid dispersions. The FTIR spectra of the glipizide and
polymers alone and in combination show the compatibility of the drug and excipients. The solid dispersions were evaluated for practical yield and in vitro dissolution. It was concluded that 1:4 ratio of drug: SSG shows better in vitro dissolution rate compared to the pure drug and marketed preparation. Further the solid dispersion with highest release rate was formulated in tablet dosage form. The angle of repose, bulk density, tapped density, carr’s index and hausner ratio were calculated for the micromeritic characterization of the powder blend. The tablets were further studied for different pharmacopoeial and non pharmacopoeial evaluation test. Similarity factor F2 was 52 and difference factor F1 was 14 for glipizide was found to be within the standards. The in vitro release from the formulation was observed three times increased from the glipizide API.