Solubility Enhancement of Poorly Water Soluble Celecoxib for Parenteral Formulations

Celecoxib, a diaryl substituted pyrazole, is practically insoluble in water which precludes its use in parenteral and liquid dosage forms. This study explores the solubility enhancement of celecoxib using hydrotropy and cosolvency solubilization approaches. The equilibrium solubility studies were performed using hydrotropes piperazine, sodium citrate, and urea and cosolvents PEG 200, PEG 400, PEG 600, DMA, Ethanol and Propylene glycol at various temperatures. Parenteral formulations using hydrotrope and cosolvents were developed and studied for accelerated stability study. The solubility of celecoxib was found to increase upto 45 times in 3M piperazine solution and upto 10232 times in PEG 600 at 25±2C. The results of solubilization study showed that the increase in solubility of celecoxib is smaller in piperazine and urea when used alone as compared to the increase in solubility which was found when these hydrotropes were used in combination with cosolvents PEG 600, PEG 400, DMA and Eth. Stability studies indicated that all the formulations stored were found to be stable for drug content, pH and change in physical appearance i.e. color, precipitation.