title: Determination of phenazopyridine in human plasma by GC-MS and its pharmacokinetics.
abstract: A sensitive, selective, and simple gas chromatography-mass spectrometry method is developed for quantitation of phenazopyridine (PAP) in human plasma using internal standard (diazepam). PAP and IS are extracted from plasma by liquid-liquid extraction and analyzed on a DB-5MS column with mass selective detector. Excellent linearity is found between 5-500 ng/mL (r = 0.9992, n = 7) for PAP in human plasma. The limit of detection is 0.3 ng/mL. Intra- and Inter-day precisions expressed as the relative standard deviation for the method are 1.37-6.69% and 1.24-6.01%, respectively. Extraction efficiency is more than 90%, and recoveries are in the range of 92.65-96.21%. This method is successfully applied for the pharmacokinetics and bioequivalence of 2 formulations of PAP in 18 healthy male volunteers who received a single 200 mg dose of each formulation.
authors.affiliation: Department of Pharmacy, Affiliated Dongfeng General Hospital, Yunyang Medical College, Hubei 442008 PR China.
authors.forename: Kai-jun
authors.initials: KJ
authors.lastname: Li
authors.forename: Qin-hua
authors.initials: QH
authors.lastname: Chen
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000700:Analgesics / Q000097:blood* / Q000493:pharmacokinetics; D001682:Biological Availability; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008297:Male; D010621:Phenazopyridine / Q000097:blood* / Q000493:pharmacokinetics; D012015:Reference Standards; D013810:Therapeutic Equivalency
chemical_list: D000700:Analgesics; D010621:Phenazopyridine