title: A sensitive and specific liquid chromatography/tandem mass spectrometry method for quantification of nevirapine and its five metabolites and their pharmacokinetics in baboons.
abstract: A highly sensitive and specific LC-MS/MS assay was developed and validated to quantify nevirapine (NVP) and its five metabolites [2-, 3-, 8-, 12-hydroxyl NVP (OHNVP) and 4-carboxyl NVP (CANVP)] simultaneously in baboon serum and the assay was used to characterize their pharmacokinetic studies of an oral-dose escalation study in baboon. The lower limit of quantification (LLOQ) for NVP and its four hydroxyl nevirapine metabolites was 1.0 ng/mL and for 4-CANVP was 5.0 ng/mL. The between-run and within-run precisions and accuracies at four quality control concentrations (1, 5, 50 and 500 ng/mL) were evaluated in baboon serum with less than 14% variation and 93-114% accuracies (n = 6), except for the LLOQ for 2-OHNVP, which had an accuracy of 115.8% for between-run validation. The pharmacokinetics of NVP and its five metabolites in non-pregnant baboons by a single-dose escalation study were also profiled. The major metabolites detected were 4-CANVP and 12-OHNVP. 3-OHNVP and 2-OHNVP were the minor metabolites with only a trace amount of 2-OHNVP detected in some pharmacokinetic samples. No 8-OHNVP was observed in all of the pharmacokinetic samples. In addition, the fragmentation for the four hydroxyl metabolite isomers is also discussed.
authors.affiliation: College of Pharmacy, The Ohio State University, 500 W. 12th Avenue, Columbus, OH 43210, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Ren
authors.forename: Patty
authors.initials: P
authors.lastname: Fan-Havard
authors.forename: Natalia
authors.initials: N
authors.lastname: Schlabritz-Loutsevitch
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Ling
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Chan
authors.forename: Zhongfa
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D019380:Anti-HIV Agents / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics*; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D019829:Nevirapine / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics*; D010215:Papio; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D019380:Anti-HIV Agents; D019829:Nevirapine