Green homogeneous liquid-liquid microextraction at high salinity conditions for the determination of nimesulide in human urine with the aid of experimental design

Green homogeneous liquid-liquid microextraction (HLLME) under high salinity conditions was proposed for the determination of nimesulide in human urine. The proposed analytical scheme consisted of the mixing of the appropriate volume of acetonitrile and sample followed by the addition of Na2SO4 solution to obtain phase separation. Following the extraction of the drug from the urine samples, high-performance chromatography-diode array detection (HPLC-PDA) was used for its determination. The main factors influencing the performance of the HLLME method were studied and optimized using a two-step experimental design (Plackett-Burman, Central Composite Design). The HLLME-HPLC-PDA method was systematically validated using the ac-curacy profiles. The detection limit was adequate and estimated to be 0.03 mu g mL(-1). The mean analytical bias (expressed as relative error) ranged between - 2.9-3.6% and the relative standard deviation (RSD) was better than 3.7%. Moreover, the beta-expectation tolerance intervals were in the range of +/- 15% demonstrating that 95% of the results will fall within the defined bias limits. The ruggedness of the herein developed protocol was assessed using Monte-Carlo simulations fol-lowed by capability analysis. The proposed scheme was applied for the determination of the drug in real urine samples following the administration of pharmaceutical formulations that contained nimesulide.

Automated summary

A green homogeneous liquid-liquid microextraction (HLLME) method was proposed for the determination of nimesulide in human urine under high salinity conditions. The main factors influencing the method's performance were studied and optimized using experimental design, with validation conducted using accuracy profiles.