A validated UPLC-MS/MS method coupled with protein precipitation and ion exchange solid phase extraction for the quantitation of porcine relaxin B29 in dog plasma and its application to a pharmacokinetic study.

Su, Chong; Sun, Hui; Yang, Hong; Yin, Lei; Zhang, Jiwen; Fawcett, John; Gu, Jingkai

Porcine relaxin is a 6 kDa peptide hormone of pregnancy with important physiological and pharmacological effects. It contains a number of analogs of which porcine relaxin B29 is one of the most important. To support the development of porcine relaxin B29 as a new drug, we established an UPLC-MS/MS method for its quantitation in dog plasma. Sample preparation by protein precipitation and ion exchange solid phase extraction was followed by UPLC on an XBridge™ BEH300 C18 column at 40 °C in a run time of only 5.5 min. Detection was performed on a Qtrap 6500 mass spectrometer using ESI in the positive ion mode with MRM of the transitions at m/z 831.7 [M+7H] → 505.4 and m/z 1162.4 [M+5H] → 226 for pRLX B29 and internal standard (recombinant human insulin), respectively. The method was linear over the concentration range 30-2000 ng/mL with no matrix effects. Intra- and inter-day precisions were < 15% with accuracies in the range 98.8-100.6%. The method was successfully applied to a pharmacokinetic study in beagle dogs after administration of a 0.15 mg/kg intravenous dose.

ION exchange (Chemistry); SOLID phase extraction; PHARMACOKINETICS; MASS spectrometers; CATIONS; RECOMBINANT human insulin

Analytical & Bioanalytical Chemistry, 2017, Vol 409, Issue 28, p6559

1618-2642

Academic Journal

10.1007/s00216-017-0604-3