title: Determination of formoterol in rat plasma by liquid chromatography-electrospray ionisation mass spectrometry.
abstract: A sensitive method for the determination of formoterol in rat plasma is described, using high performance liquid chromatographic separation with tandem mass spectrometry. Samples were purified using liquid-liquid extraction and separated on CAPCELL PAK C18 UG120 (2.0 x 150 mm) with a mobile phase consisting of a mixture of methanol- 50 mM ammonium hydrogen carbonate (1:1 v/v). Detection was performed with a TSQ 7000 mass spectrometer using positive ion electrospray ionisation, monitoring the shift from precursor ions for formoterol at m/z 344.9 to product ions of m/z 121.0. The limit of quantitation of the method was found to be 0.1 ng/ml, when using 0.1 ml plasma. Plasma concentrations of formoterol could be quantified from 0.15 to 7.01 ng/ml, allowing the analysis of samples up to 32 h after a single oral dose of formoterol fumarate (0.25 mg) to rats.
authors.affiliation: Research Department, Saitama Daiichi Pharmaceutical Co., Ltd., Kasukabe, Saitama, Japan. kakubari@sdsk.co.jp
authors.forename: I
authors.initials: I
authors.lastname: Kakubari
authors.forename: H
authors.initials: H
authors.lastname: Dejima
authors.forename: K
authors.initials: K
authors.lastname: Miura
authors.forename: Y
authors.initials: Y
authors.lastname: Koga
authors.forename: H
authors.initials: H
authors.lastname: Mizu
authors.forename: T
authors.initials: T
authors.lastname: Takayasu
authors.forename: H
authors.initials: H
authors.lastname: Yamauchi
authors.forename: S
authors.initials: S
authors.lastname: Takayama
authors.forename: K
authors.initials: K
authors.lastname: Takayama
mesh_terms: D000318:Adrenergic beta-Agonists / Q000097:blood*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004983:Ethanolamines / Q000097:blood*; D000068759:Formoterol Fumarate; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012015:Reference Standards; D015203:Reproducibility of Results; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D012996:Solutions; D000068759:Formoterol Fumarate