title: Determination of oxycodone, noroxycodone and oxymorphone by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry in human matrices: in vivo and in vitro applications.
abstract: The opioid analgesic oxycodone is widely abused and increasingly associated with overdose deaths. A sensitive analytical method was developed for oxycodone and its metabolites, noroxycodone and oxymorphone, in human plasma, urine (±enzymatic hydrolysis at 50°C for 16 h) and liver microsomes (HLMs). Liquid-liquid extraction was followed by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. The calibration range was 0.2-250 ng/mL for plasma and HLM and 10-5000 ng/mL for urine. Intra- and interrun accuracies were within 13.3% of target; precisions were within 12.8% for all matrices. Recoveries from plasma were: oxycodone, 75.6%; noroxycodone, 37.4% and oxymorphone, 18.2%. Analytes exhibited room temperature stability in plasma and urine up to 24 h, and freeze-thaw stability in plasma up to three cycles. In 24-h hydrolyzed urine from subjects administered intranasal oxycodone (30 mg/70 kg, n = 5), mean concentrations (ng/mL) and % daily doses excreted were: oxycodone, 1150, 6.53%; noroxycodone, 1330, 7.81% and oxymorphone, 3000, 17.1%. Oxycodone incubated with HLM produced more noroxycodone than oxymorphone. With a panel of recombinant human cytochrome P450s (CYPs), CYP2C18 and CYP3A4 produced the most noroxycodone, whereas CYP2D6 produced the most oxymorphone. These results demonstrate a new method suitable for both in vivo and in vitro metabolism and pharmacokinetic studies of oxycodone.
authors.affiliation: 1Center for Human Toxicology, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Wenfang B
authors.initials: WB
authors.lastname: Fang
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Lofwall
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Walsh
authors.forename: David E
authors.initials: DE
authors.lastname: Moody
mesh_terms: D000701:Analgesics, Opioid / Q000097:blood; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019389:Cytochrome P-450 CYP2D6 / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D006801:Humans; D059625:Liquid-Liquid Extraction; D008862:Microsomes, Liver / Q000737:chemistry; D009019:Morphinans / Q000097:blood* / Q000652:urine; D010098:Oxycodone / Q000097:blood* / Q000652:urine; D010111:Oxymorphone / Q000097:blood* / Q000652:urine; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D000701:Analgesics, Opioid; D009019:Morphinans; C077256:noroxycodone; D010111:Oxymorphone; D010098:Oxycodone; D001189:Aryl Hydrocarbon Hydroxylases; C082185:CYP2C18 protein, human; D019389:Cytochrome P-450 CYP2D6; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human