title: A sensitive liquid chromatography-electrospray ionization-mass spectrometry method for the simultaneous determination of pentoxyverine citrate and guaifenesin in human plasma---application to pharmacokinetic and bioequivalence studies.
abstract: A sensitive and specific liquid chromatography-electrospray ionization-mass spectrometry method for the identification and quantification of pentoxyverine citrate and guaifenesin in human plasma has been developed. After extraction from plasma samples by ethyl acetate, the internal standard and analytes were separated by high-performance liquid chromatographic on a Shim-pack VP-ODS C(18) column (150 x 2.0 mm) using a mobile phase consisting of A (methanol) and B (0.4% glacial acetic acid and 4 mmol/L ammonium acetate) (A:B, 43 : 57). Analysis was performed on a Shimadzu LC/MS-2010A in selected ion monitoring mode with a positive electrospray ionization interface. The method was linear in the concentration range of 1.0-640.0 ng/mL for pentoxyverine citrate and 0.025-6.4 microg/mL for guaifenesin. The inter- and intra- precision were all within 12% and accuracy ranged from 85 to 115%.The lower limits of quantification were 1.0 ng/mL for pentoxyverine citrate and 25.0 ng/mL for guaifenesin. The extraction recovery was on average 81.95% for pentoxyverine citrate and 89.03% for guaifenesin. This is the first assay method reported for the simultaneous determination of pentoxyverine citrate and guaifenesin in plasma using one chromatographic run.
authors.affiliation: Institute of Clinical Pharmacology, College of Medicine, Nanchang University, 461 Bayi Road, Nanchang, Jiangxi, People's Republic of China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Wen
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Chunhua
authors.initials: C
authors.lastname: Xia
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.forename: Wenwei
authors.initials: W
authors.lastname: Xu
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Cheng
authors.forename: Jun
authors.initials: J
authors.lastname: Gao
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Xiong
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003517:Cyclopentanes / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D004355:Drug Stability; D005100:Expectorants / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics*; D006140:Guaifenesin / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics*; D006801:Humans; D016014:Linear Models; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013810:Therapeutic Equivalency
chemical_list: D003517:Cyclopentanes; D005100:Expectorants; C018861:carbetapentane; D006140:Guaifenesin