title: Liquid chromatographic-tandem mass spectrometric method for the quantitation of sildenafil in human plasma.
abstract: A method to determine sildenafil in human plasma involving liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed. Sildenafil and the internal standard (I.S.), diazepam, are extracted from human plasma with ether-dichloromethane (3:2, v/v) at basic pH and analyzed by reversed-phase high-performance liquid chromatography (HPLC) using methanol-10mM ammonium acetate pH 7.0 (85:15, v/v) as the mobile phase. Detection by electrospray positive ionization mass spectrometry in the multiple-reaction monitoring mode was linear over the concentration range 0.125-40.0 ng/ml. Intra- and inter-day precision of the assay at four concentrations within this range were 2.5-8.0%. The method was used to evaluate plasma concentration-time profiles in healthy volunteers given an oral dose of 20mg sildenafil as a combination tablet also containing apomorphine.
authors.affiliation: Research Center for Drug Metabolism, College of Life Science, Jilin University, Changchun 130023, China.
authors.forename: Yingwu
authors.initials: Y
authors.lastname: Wang
authors.forename: Jiang
authors.initials: J
authors.lastname: Wang
authors.forename: Yimin
authors.initials: Y
authors.lastname: Cui
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*; D003975:Diazepam / Q000032:analysis / Q000737:chemistry; D006801:Humans; D010879:Piperazines / Q000097:blood*; D011687:Purines; D012015:Reference Standards; D015203:Reproducibility of Results; D000068677:Sildenafil Citrate; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013450:Sulfones
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate; D003975:Diazepam