Abstract
Glimepiride, an oral hypoglycemic second generation drug, has problems in bioavailability and bioequivalence due to its poor water solubility. An attempt was made to improve the bioavailability with an improvement in dissolution of glimepiride through the formulation of tablet containing solid dispersion of glimepiride- polymers i.e. Sodium Starch Glycolate (SSG) / Hydroxy Propyl Cellulose (HPC)/ Crosscarmellose Sodium (CCS)/Eudragit E-100. The binary systems of glimepiride i.e. both physical mixture as well as solid dispersions were prepared with drug and polymers. The solid dispersions were prepared by solvent evaporation method using methanol as solvent. Infrared (IR) spectroscopy was performed to identify any physicochemical interaction between the drug and the carrier(s). The dissolution profile of active pharmaceutical ingredient (API), marketed product and solid dispersion were compared. Differential Scanning Calorimetry (DSC) of solid dispersion elucidate that the crystal structure of glimepiride was converted into amorphous form. The optimized formulation was compressed with different excipients into tablet dosage form. The tablets formulation under investigation was then characterized for their various physicochemical properties such as weight variation, % friability, disintegration and in vitro dissolution profiles. It was observed that solid dispersions were better than physical mixture in dissolution. The result showed no interaction between the drug and polymer, percentage yield of 69.80% to 96.50%, amorphous state of solid dispersion and significant improvement in dissolution upto 98.81% with drug: SSG in 1:3 ratio. Thus, the solid dispersion technique can be successfully used for the improvement of dissolution of glimepiride.
