Determination of formoterol in rat plasma by liquid chromatography-electrospray ionisation mass spectrometry

• Published in: Pharmazie Vol. 62; no. 2; pp. 94 - 95
• Main Authors: Kakubari, I., Dejima, H., Miura, K., Koga, Y., Mizu, H., Takayasu, T., Yamauchi, H., Takayama, S., Takayama, K.
• Format: Journal Article
• Language: English
• Published: Germany Govi-Verlag 01.02.2007
• Subjects: Adrenergic beta-Agonists - blood; Animals; Chromatography, High Pressure Liquid; Ethanolamines - blood; Formoterol Fumarate; Male; Rats; Rats, Wistar; Reference Standards; Reproducibility of Results; Solutions; Spectrometry, Mass, Electrospray Ionization
• ISSN: 0031-7144
• DOI: 10.1691/ph.2007.2.6134

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 × 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.