Rapid Determination of Nimesulide by Capillary Zone Electrophoresis in Various Pharmaceutical Formulations

Nimesulide is a popular non-steroidal anti-inflammatory drug (NSAID) and a cyclooxygenase-2 inhibitor available in more than 50 countries worldwide. A rapid and simple method for nimesulide determination is presented. Experimental parameters based on a previously published work were revised and adopted into a method with significantly better performance: pH was shifted from 8.10 to 9.25, borate background electrolyte concentration from 10 to 60 mM—resulting in a run time less than 4 min, and number of theoretical plates greater than 100,000. The method was validated and applied for the determination of nimesulide in three formulations with the active substance of nimesulide: tablets, gel, and powder (in sachets for oral suspension). Also, the tablets were tested for uniformity of content of single-dose preparations according to Ph. Eur.