Solubilization Of Nimesulide; Use Of Co-Solvents
Solubility of nimesulide in various solvents and solvent-co-solvent mixtures was determined in relatlon to the development of parenteral formulations. Solubility was low in aqueous solvents. Solubility Increased on solubilization of drug in semi-polar solvents and non-ionic surfactants. Solubility increased drastically (>70 mg/rnl) when polyethylene glycol 300 and polyethylene glycol 400 were used as solvents. The minimum concentration of polyethylene glycol required for solubility to be greater than 50 mg/ml was found to be 80%. It was recommended that solvent containing 90% polyethylene glycol and 10% co-solvent (alcohol, propylene glycol,Tween 80 and Brij 30) with solubility greater than 65 mg/ml can be used in parenteral formulations of nimesuilde. Alternatively 8% co-solvent can be mixed with 2% benzyl alcohol which acts as an anaesthetic agent.