Simultaneous determination for oxicam non-steroidal anti-inflammatory drugs in human serum by liquid chromatography–tandem mass spectrometry

Abstract A high-performance liquid chromatography–tandem mass spectrometry (LC/MS/MS) technique was developed for the simultaneous determination of five non-steroidal anti-inflammatory oxicam drugs (ampiroxicam, tenoxicam, piroxicam, meloxicam and lornoxicam) in human plasma. These five oxicam drugs and isoxicam (internal standard) were extracted from human plasma with an Oasis ® MAX cartridge column and analysed on a Unison UK-C18 column (2.0mm×100mm, 3μm) with an acetonitrile:10mM formic ammonium buffer (pH 3.0) (50:50) mobile phase at 0.20ml/min at 37°C. The analytes were detected using a tandem mass spectrometer, equipped with an electrospray ion source (ESI). The instrument was used in multiple-reaction-monitoring (MRM) mode. The extraction yields from a 200μl human plasma sample (containing 10ng of each drugs) with the Oasis ® MAX cartridge column were 93.3–102.5%. The detection limits were 0.01–6.5ng/ml (S/N=3). Our developed method is very useful for the simultaneous determination of five oxicam (non-steroidal anti-inflammatory) drugs in human plasma by LC/MS/MS.