Abstract
An analytical method based on liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) was developed and validated for the determination of etoricoxib in spiked human plasma and pharmaceutical dosage forms. Etoricoxib and piroxicam (internal standard) were extracted from the plasma by liquid–liquid extraction using tert‐butyl methyl ether as extraction solvent and separated on a C18 analytical column (50 mm×3.0 mm I.D.). The mobile phase consisted of acetonitrile:water (95:5)/0.1% acetic acid (90:10, v/v). Detection was carried out by positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode. The chromatographic separation was obtained within 2.0 min and was linear in the concentration range of 1–5000 ng/mL. The mean extraction recoveries of etoricoxib and piroxicam from plasma were 96.09 and 95.54%, respectively. Method validation investigated parameters such as the linearity, precision, accuracy, specificity, and stability, giving results within the acceptable range. Moreover, the proposed method was successfully applied for routine quality control analysis of pharmaceutical products and the results compared with those obtained by the RP‐HPLC method, showing significant correlation (P>0.05).
Acknowledgments
The authors wish to thank CNPq (Conselho Nacional de Desenvolvimento Cient) and Merck Research Laboratories for their support.