title: Quantitation of iptakalim in human plasma by high-performance liquid chromatography-tandem mass spectrometry.
abstract: This paper describes a rapid and sensitive analytical method for the quantitation of iptakalim, a novel antihypertensive drug, in human plasma. The method is based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) using sildenafil as internal standard. Sample preparation involved liquid-liquid extraction with dichloromethane-diethyl ether (2:3, v/v) in a basic environment. Chromatography was carried out on an amino column with a mobile phase consisting of acetonitrile-water (55:45, v/v, water containing 0.5% formic acid). Detection employed electrospray ionization (ESI) tandem mass spectrometry in the multiple-reaction-monitoring (MRM) mode. The assay was linear in the concentration range of 0.5-100 ng/ml with a lower limit of quantitation (LLOQ) of 0.5 ng/ml. Intra- and inter-day precision (R.S.D.) were <4.5% and <12.0%, respectively and the accuracy (R.E.) was in the range +/-5%. The method was successfully applied to a single oral dose pharmacokinetic study in human volunteers.
authors.affiliation: Research Center for Drug Metabolism, College of Life Science, Jilin University, Changchun 130023, China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Teng
authors.forename: Yingwu
authors.initials: Y
authors.lastname: Wang
authors.forename: Yunbiao
authors.initials: Y
authors.lastname: Tang
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Fang
authors.forename: J Paul
authors.initials: JP
authors.lastname: Fawcett
authors.forename: Jingkai
authors.initials: J
authors.lastname: Gu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D011437:Propylamines / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C502260:N-(1-methylethyl)-1,1,2-trimethylpropylamine; D011437:Propylamines