Validated UPLC/Q-TOF-MS Method for Simultaneous Determination of Aceclofenac, Paracetamol and Chlorzoxazone in Human Plasma and its Application to Pharmacokinetic Study

In the presented work the ultra-performance liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC/Q-TOF-MS) method has been developed for pharmacokinetic study of some antiinflammatory and analgesic drugs in human plasma. The aceclofenac, paracetamol, and chlorzoxazone were analyzed by Acquity UPLC BEH C18 (100.0_2.1 mm, 1.7 lm) column using isocratic mobile phase consisting of acetonitrile-2mM ammonium acetate (50:50, v/v) at a flow rate of 0.20 mL/min. The Q-TOF mass spectrometer was operated in positive ionization mode and quantization was done using the MS/MS transitions m/z 354.07 to 215.07 for aceclofenac, 152.07 to 110.06 for paracetamol and 170.00 to 134.00 for chlorzoxazone. The calibration curves were linear over the concentration range of 1–1000 ng/mL for all the drugs. The developed method was validated according to ICH guidelines. The method was applied for pharmacokinetic study of tablets containing aceclofenac, paracetamol, and chlorzoxazone in human plasma.