Solubility Enhancement of Poorly Water Soluble Drug Zaltoprofen by Mixed Hydrotropy Approach

The present study is probably the earliest attempt to enhance Solubility of Zaltoprofen by using mixed hydrotropy and mixed solvency approaches.  Zaltoprofen is selected as model drug because it is practically insoluble in water hence there is need to increase the solubility for better absorption and improved therapeutic efficacy. In the preformulation study physical compatibility of the drug-excipient was screened  and compatibility was observed between Zaltoprofen and selected solubilizers. In the drug solubilizers interference study no interference was observed in UV spectrophometric analysis of Zaltoprofen in presence of employed solubilizers. Aqueous solubility of Zaltoprofen was found 0.028 mg/ml. The solubilizers sodium acetate, sodium benzoate and sodium salicylate, ethanol, PEG 600, piperazine anhydrous, were selected for solubilization studies on the basis of solubility enhancement ratio. The solubility enhancement ratio in sodium citrate, citric acid, urea, PEG 6000, PEG 4000, PEG 200, PEG 400, propylene glycol and glycerin were found to be less as compare to selected solubilizers. The solubility determination of drug in hydrotropic solutions was carried out at room temperature and solubilizing power of different hydrotropes could be ranked as: Piperazine anhydrous > sodium salicylate > sodium benzoate > sodium acetate > PEG 600. From the equilibrium solubility curves of Zaltoprofen in solubilisers it was concluded that increase in the solubility was nonlinear function with respect to the hydrotrope concentration. Keywords: Mixed hydrotropy, Zaltoprofen, solubility, selective COX2 inhibitor