title: Determination of tamsulosin in human aqueous humor and serum by liquid chromatography-electrospray ionization tandem mass spectrometry.
abstract: A simple, sensitive and selective LC-MS/MS method was developed for the determination of tamsulosin in human aqueous humor and serum to study the recently reported eye-related adverse effects of this alpha(1)-blocker drug. Aqueous humor samples were analyzed by direct injection, after addition of the internal standard, labetalol. Liquid-liquid extraction with ethyl acetate was used for serum sample preparation. The chromatographic separation was performed on a reversed phase column by gradient elution with acetonitrile -0.1% formic acid at a flow-rate of 0.2 ml/min. Detection and quantification of the analytes were carried out with a linear ion trap mass spectrometer, using positive electrospray ionization (ESI) and multiple reaction monitoring (MRM). The limit of quantification was 0.1 ng/ml for both aqueous humor and serum samples and linearity was obtained over the concentration ranges of 0.1-4.7 ng/ml and 0.1-19.3 ng/ml for aqueous humor and serum samples, respectively. Acceptable accuracy and precision were obtained for concentrations within the standard curve ranges. The method has been used for the determination of tamsulosin in aqueous humor and serum samples from patients that were on tamsulosin medication and underwent cataract surgery.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland. pekka.keski-rahkonen@uku.fi
authors.forename: Pekka
authors.initials: P
authors.lastname: Keski-Rahkonen
authors.forename: Olavi
authors.initials: O
authors.lastname: Pärssinen
authors.forename: Esa
authors.initials: E
authors.lastname: Leppänen
authors.forename: Timo
authors.initials: T
authors.lastname: Mauriala
authors.forename: Marko
authors.initials: M
authors.lastname: Lehtonen
authors.forename: Seppo
authors.initials: S
authors.lastname: Auriola
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000097:blood* / Q000493:pharmacokinetics; D001082:Aqueous Humor / Q000378:metabolism*; D002386:Cataract / Q000097:blood / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods* / Q000592:standards; D013449:Sulfonamides / Q000097:blood* / Q000493:pharmacokinetics; D000077409:Tamsulosin; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards
chemical_list: D000317:Adrenergic alpha-Antagonists; D013449:Sulfonamides; D000077409:Tamsulosin