title: Determination of tamsulosin in human plasma by liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study.
abstract: Tamsulosin, a selective α₁-adrenoceptor antagonist, is used for the treatment of benign prostatic hyperplasia (BPH). We developed and validated a rapid, sensitive, and simplified liquid chromatography analytical method utilizing tandem mass spectrometry (LC-MS/MS) for the determination of tamsulosin in human plasma. After liquid-liquid extraction with methyl t-butyl ether, chromatographic separation of tamsulosin was achieved using a reversed-phase Luna C₁₈ column (2.0 mm × 50 mm, 5 μm particles) with a mobile phase of 10 mM ammonium formate buffer (pH 3.5)-methanol (25:75, v/v) and quantified by MS/MS detection in ESI positive ion mode. The flow rate of the mobile phase was 200 μL/min and the retention times of tamsulosin and the internal standard (IS, diphenhydramine) were 0.8 and 0.9 min, respectively. The calibration curves were linear over a range of 0.01-20 ng/mL (r>0.999). The lower limit of quantification using 500 μL of human plasma was 0.01 ng/mL. The mean accuracy and precision for intra- and inter-day validation of tamsulosin were both within acceptable limits. The present LC-MS/MS method showed improved sensitivity for quantification of tamsulosin in human plasma compared with previously described analytical methods. The validated method was successfully applied to a pharmacokinetic study in humans.
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Chang-Ik
authors.initials: CI
authors.lastname: Choi
authors.forename: Hye-In
authors.initials: HI
authors.lastname: Lee
authors.forename: Jung-Woo
authors.initials: JW
authors.lastname: Bae
authors.forename: Yun-Jeong
authors.initials: YJ
authors.lastname: Lee
authors.forename: Ji-Yeong
authors.initials: JY
authors.lastname: Byeon
authors.forename: Choon-Gon
authors.initials: CG
authors.lastname: Jang
authors.forename: Seok-Yong
authors.initials: SY
authors.lastname: Lee
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004155:Diphenhydramine / Q000097:blood; D004355:Drug Stability; D006801:Humans; D016014:Linear Models; D059625:Liquid-Liquid Extraction; D008297:Male; D015203:Reproducibility of Results; D013449:Sulfonamides / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D000077409:Tamsulosin; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D013449:Sulfonamides; D004155:Diphenhydramine; D000077409:Tamsulosin