Determination of a 'GW cocktail' of cytochrome P450 probe substrates and their metabolites in plasma and urine using automated solid phase extraction and fast gradient liquid chromatography tandem mass spectrometry

• Published in: Rapid communications in mass spectrometry Vol. 13; no. 23; pp. 2305 - 2319
• Main Authors: Scott, Rebecca J., Palmer, Jonathan, Lewis, Ivor A. S., Pleasance, Stephen
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.01.1999
• Subjects: Automation; Caffeine - analogs & derivatives; Caffeine - blood; Caffeine - pharmacokinetics; Caffeine - urine; Chlorzoxazone - analogs & derivatives; Chlorzoxazone - blood; Chlorzoxazone - pharmacokinetics; Chlorzoxazone - urine; Chromatography, Gas - methods; Chromatography, High Pressure Liquid - methods; Cytochrome P-450 Enzyme System - metabolism; Debrisoquin - analogs & derivatives; Debrisoquin - blood; Debrisoquin - pharmacokinetics; Debrisoquin - urine; Diclofenac - analogs & derivatives; Diclofenac - blood; Diclofenac - pharmacokinetics; Diclofenac - urine; Glucuronidase; Humans; Indicators and Reagents; Midazolam - analogs & derivatives; Midazolam - blood; Midazolam - pharmacokinetics; Midazolam - urine; Reproducibility of Results; Sensitivity and Specificity; Substrate Specificity; Theophylline - blood; Theophylline - pharmacokinetics; Theophylline - urine
• ISSN: 0951-4198; 1097-0231
• DOI: 10.1002/(SICI)1097-0231(19991215)13:23<2305::AID-RCM790>3.0.CO;2-G

A mass spectrometry based method for the simultaneous determination of an in vivo Greenford‐Ware or ‘GW cocktail’ of CYP450 probe substrates and their metabolites in both human plasma and urine is described. The probe substrates, caffeine, diclofenac, mephenytoin, debrisoquine, chlorzoxazone and midazolam, together with their respective metabolites and stable isotope labelled internal standards, are simultaneously extracted from the biological matrix using solid phase extraction in 96‐well microtitre plate format, automated by means of a custom built Zymark robotic system. The extracts are analysed by fast gradient high performance liquid chromatography (HPLC) with detection by tandem mass spectrometry (MS/MS) using thermally and pneumatically assisted electrospray ionisation in both positive and negative ion modes and selected reaction monitoring. The methods are specific, accurate and precise with intra‐ and inter‐assay precision (%CV) of less than 15% for all analytes. Copyright © 1999 John Wiley & Sons, Ltd.