Greener validated spectrophotometric investigation optimized with Box–Behnken design for nimesulide in pharmaceutical formulations

Nimesulide was evaluated in pharmaceutical formulations by forming a coloured product with potassium permanganate (KMnO 4 ) under alkaline conditions (NaOH), and the resulting absorbance was monitored at 601 nm. A Box–Behnken design was employed to optimise reaction time, KMnO 4 concentration and nimesulide concentration. The selected operating conditions were 11 min reaction time, 0.001 M KMnO 4 , 0.028 M nimesulide and 0.1 M NaOH. Validation covered specificity, linearity, accuracy, precision, detection and quantitation limits, and robustness in line with ICH-oriented requirements. The method showed a linear response from 1.8 to 22.5 µg/mL; the LOD and LOQ were 0.56 and 1.70 µg/mL, respectively. Recovery values were 99.225–99.794%, while intraday and interday precision produced %RSD ranges of 0.201–0.763% and 0.342–1.025%, respectively. We also examined sustainability and practical performance using AGREE, BAGI, AES, EPPI, and RAPI. Taken together, the analytical and greenness results support using the procedure to determine nimesulide in bulk material and pharmaceutical formulations.