Development of a sensitive liquid chromatography-electrospray ionization mass spectrometry method for the measurement of KW-5139 in rat plasma

• Published in: Biomedical chromatography 2000-04, Vol.14 (2), p.77-81
• Main Authors: Yamaguchi, Kazuo, Takashima, Michio, Uchimura, Tatsuo, Kobayashi, Satoshi
• Format: Article
• Language: English
• Subjects: Animals; Chromatography, Liquid - methods; Gastrointestinal Agents - blood; Mass Spectrometry - methods; Motilin - analogs & derivatives; Motilin - blood; Rats; Sensitivity and Specificity
• ISSN: 0269-3879; 1099-0801
• DOI: 10.1002/(SICI)1099-0801(200004)14:2<77::AID-BMC928>3.0.CO;2-A

A sensitive method for the determination of a prokinetic peptide, KW‐5139 (Leu13–motilin), in rat plasma has been developed utilizing liquid chromatography‐electrospray ionization mass spectrometry (LC‐ESI‐MS). KW‐5139 was separated by reversed‐phase HPLC, with a mixture of 75 mM ammonium formate (pH 3.0) and acetonitrile (4:1, v/v), and monitored by single ion recording (SIR)‐ESI‐MS at m/z 894 ([M+3H]3+). Simple protein precipitation and the LC‐ESI‐MS analysis allowed the determination of KW‐5139 in rat plasma with the mean precision and accuracy at the lower limit of quantitation (LLOQ, 0.5 ng/mL) of 5.7 and 11.2%, respectively. The method was applied to the monitoring of the plasma time–concentration profile of KW‐5139, intravenously administered to rats at a dose of 1 µg/kg. Copyright © 2000 John Wiley & Sons, Ltd.