An Approach to Enhance Solubility of Gatifloxacin by Solid Dispersion Tecnique

Bioavailability can be increased by changing in disintegration and dissolution the aqueous solubility is lesser than 1μg/ml will definitely create a bioavailability problem and thereby affecting the efficacy of the drug. There are number of methods through which aqueous solubility of the drug can be increased in which solid dispersions is one of the effective and accepted technique in the pharmaceutical industry. The solid dispersion was defined as the dispersion of one or more active ingredients in an inert carrier or matrix. The purpose of the study was to improve the physicochemical properties of gatifloxacin like solubility, dissolution properties and stability of poorly soluble drug by forming dispersion with mannitol as water soluble carrier. The solid dispersion of gatifloxacin by Physical triturating method, kneading and Solvent evaporation were prepared using 1:1, 1:2,1:3 and 1:4 ratios of drug and polymer (mannitol). The saturation solubility was carried using USP type XXIV (paddle) type dissolution apparatus. The prepared dispersion showed marked increase in the saturation solubility and dissolution rate of gatifloxacin than that of pure drug. The dispersion with mannitol (1:4) by kneading method showed faster dissolution rate (99.85%) as compared to other dispersions with urea (1:1,1:2 and 1:3) whichever prepared by physical mixture and solvent evaporation method. The FT-IR shows the complexation and there were no interactions. Finally solid dispersion of gatifloxacin: mannitol prepared as 1:4 ratio by kneading method showed excellent physicochemical characteristics and was found to be described by dissolution release kinetics and was selected as the best formulation in this study.