title: Liquid chromatography-electrospray ionization tandem mass spectrometric determination of lornoxicam in human plasma.
abstract: A rapid, sensitive and selective liquid chromatography-electrospray ionization tandem mass spectrometric (LC-ESI-MS/MS) method for the determination of lornoxicam in human plasma was developed. Lornoxicam and isoxicam (internal standard) were extracted from human plasma with ethyl acetate at acidic pH and analyzed on a Sunfire C18 column with the mobile phase of methanol:ammonium formate (10 mM, pH 3.0) (70:30, v/v). The analyte was detected using a mass spectrometer, equipped with electrospray ion source. The instrument was set in the multiple-reaction-monitoring mode. The standard curve was linear (r = 0.9998) over the concentration range of 0.50-500 ng/mL. The coefficient of variation and relative error for intra- and inter-assay at four QC levels were 0.7 to 4.2% and -4.5 to 5.0%, respectively. The recoveries of lornoxicam and isoxicam were 87.8% and 66.5%, respectively. The lower limit of quantification for lornoxicam was 0.50 ng/mL using a 200 pL plasma sample. This method was successfully applied to a pharmacokinetic study of lornoxicam after oral administration of lornoxicam (8 mg) to humans.
authors: Drug Metabolism and Bioanalysis Laboratory, College of Pharmacy, Wonkwang University, Iksan 570-749, Korea.
authors: Young Hoon
authors: YH
authors: Kim
authors: Hye Young
authors: HY
authors: Ji
authors: Eun-Seok
authors: ES
authors: Park
authors: Soo-Wan
authors: SW
authors: Chae
authors: Hye Suk
authors: HS
authors: Lee
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D019540:Area Under Curve; D002138:Calibration; D002853:Chromatography, Liquid; D006207:Half-Life; D006801:Humans; D008297:Male; D015394:Molecular Structure; D010894:Piroxicam / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D010894:Piroxicam; C059451:lornoxicam