Solubilization of indometacin.

Three methods were employed for the solubilization of indometacin as an example of antirheumatic drugs, employing:--Non-ionic surface-active agents such as Tween 80 and 40, Myrj 53 and Brij 99,--urea and sodium citrate--urea-indometacin coprecipitate. The solubility of indometacin by nonionic surface active agents was in the following order: Tween 80 and Brij 99 greater than Tween 40 greater than Myrj 53. The efficiency of solubilization by these surfactants decreased as the polyoxyethylene chain increased. Urea increases the solubility of indometacin due to enhancing the solvation of the drug by water. Up to a concentration of 0.2 M sodium citrate increases the solubility of indometacin, followed by a sharp decline in the solubility by increasing its concentration of sodium citrate. Urea-indometacin coprecipitate show slight increase in the solubility of the drug.