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A liquid chromatography/atmospheric pressure ionization tandem mass spectrometry quantitation method for nevirapine and its two oxidative metabolites, 2‐hydroxynevirapine and nevirapine 4‐carboxylic acid, and pharmacokinetics in baboons
Author(s) -
Liu Zhongfa,
FanHavard Patty,
Xie Zhiliang,
Ren Chen,
Chan Kenneth K.
Publication year - 2007
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3136
Subject(s) - chemistry , chromatography , selected reaction monitoring , formic acid , nevirapine , electrospray ionization , atmospheric pressure chemical ionization , mass spectrometry , tandem mass spectrometry , liquid chromatography–mass spectrometry , chemical ionization , ionization , organic chemistry , medicine , ion , family medicine , human immunodeficiency virus (hiv) , antiretroviral therapy , viral load
Abstract A rapid highly sensitive and specific electrospray ionization (ESI) liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for quantification of nevirapine (NVP) and its two metabolites, 2‐hydroxynevirapine (2‐OHNVP) and nevirapine 4‐carboxylic acid (4‐CANVP), in baboon serum was developed and validated. Nevirapine, 2‐OHNVP, 4‐CANVP, and the internal standard, hesperetin, were extracted from baboon serum with ethyl acetate. Components in the extract were separated on a 50 × 2.1 mm Aquasil C 18 5 µm stainless steel column by isocratic elution with 40% acetonitrile/0.1% formic acid at a flow rate of 0.2 mL/min. The liquid flow was passed through a pre‐source splitter and 5% of the eluant was introduced into the atmospheric pressure ionization (API) source. The components were analyzed in the multiple‐reaction monitoring (MRM) mode as the precursor/product ion pair of m/z 267.2/226.2 for NVP, 283.0/161.2 for 2‐OHNVP, 297.2/279.2 for 4‐CANVP, and 303.2/177.2 for hesperetin. Linear calibration curves were obtained in the range of 1–1000 ng/mL for NVP and 2‐OHNVP and 5–1000 ng/mL for 4‐CANVP, using 0.2 mL baboon serum, respectively. The within‐day and between‐day precisions were <10% for NVP and 2‐OHNVP, and <11.5% for 4‐CANVP. Due to the similar structures and fragmentation patterns of 2‐OHNVP and 3‐OHNVP, it is not expected that the LC/MS/MS can differentiate 2‐OHNVP and 3‐OHNVP and they were assayed as a composite. The method was applied to a single‐dose escalation study of NVP in non‐pregnant baboons ( Papio anubis ) to characterize the pharmacokinetics of NVP, 2‐OHNVP plus 3‐OHNVP, and 4‐CANVP, and to determine the appropriate dose necessary to achieve comparable peak serum concentration of NVP as reported in healthy human adults. Copyright © 2007 John Wiley & Sons, Ltd.