A capillary zone electrophoretic method for the determination of nimesulide in pharmaceutical preparation and serum

A simple capillary zone electrophoretic (CZE) method was developed to determine nimesulide in pharmaceutical tablet formulations and serum. Method development was conducted in a fused-silica capillary using a background electrolyte of 10 mM borate buffer containing 10% ethanol at pH 8.1, injecting for 1 s by vacuum injection, applying 30 kV. Salicylic acid was found to be a good internal standard (IS) and detection was performed at 200 nm. Nimesulide and IS appeared at average migration times (RSD%) of 7.2 (0.75%) and 10.4 (0.91%) min, respectively. The limit of detection (S/N= 3) and limit of quantitation (S/N= 10) were 2.2 x 10(-6) M and 6.7 x 10(-6) M, respectively. The method was applied to the tablets containing 100 mg nimesulide and the results were compared to those of UV-spectrophotometry. The recoveries of methods (as mean (mg) RSD%) were found to be 99.6 +/- 1.59 for CZE and 98.9 +/- 1.04 for UV spectrophotometry. The proposed method was also applied for the determination of nimesulide in serum by the standard addition technique. The proposed method is sensitive, precise, and easy to use for the determination of nimesulide in tablets and serum.