IMPROVEMENT IN MICROMERITIC PROPERTIES AND DISSOLUTION RATE OF GLIMEPIRIDE

Abstract

Glimepiride is a third generation hypoglycemic therapeutic agent prescribed for the treatment of non-insulin dependent diabetes mellitus. It is relatively insoluble in water, with poor gastro intestinal dissolution, slow absorption rate and low bioavailability. The objective of the present research is to improve the micromeritic properties, solubility and dissolution rate of glimepride by solid dispersion technique. The solid dispersions were prepared by solvent evaporation method using hydrophilic carriers like PEG6000, PEG10000 and gelucire 44/14. Phase solubility studies showed negative values for all the 3 carriers at various concentrations (0-5% w/v), indicating the spontaneous nature of solubilization. FT-IR and DSC studies revealed that glimepride is compatible with carriers used in this study. Kawakita analysis revealed reduced cohesiveness and improved flowability for solid dispersions. In vitro dissolution study showed maximum dissolution of 75% in 30 min for gelucire 44/14 based solid dispersion with 1:5 ratio of drug to carrier (F9). Q 30 values for formulation F9 showed nearly 10 fold increase in dissolution rate compared to glimepride. The mean dissolution time for solid dispersion F9 decreased from 33 min to 18 min. Hence solid dispersion F9 was selected as the optimized formulation to improve micromeiritc properties, solubility and dissolution rate of glimepiride.