Development and validation of an LC-MS/MS method for pharmacokinetic study of lobetyolin in rats

A simple and selective liquid chromatography tandem with mass spectrometry (LC-MS/ MS) method for quantification of lobetyolin in rat plasma was developed and validated. Chromatographic separation was achieved on a Thermo ODS C18 reversed-phase column using 0.1% aqueous formic acid-methanol (50:50, v/v) in an isocratic elution mode at a flow rate of 0.4 mL.min-1. LC/MS performance was done in a positive ion ESI mode and the MS/MS transitions were monitored at m/z 419.3 [M+Na]+ -> m/z 203.1 for lobetyolin and m/z 394.9 [M+Na]+ -> m/z 231.9 for IS, respectively. The assay exhibited a linear dynamic range over 1.0-500 ng.mL-1 for lobetyolin in plasma. Both the precision (%RSD) and accuracy (RE%) were within acceptable criteria (<15%). Recoveries ranged from 87.0% to 95.6%, and the matrix effects were from 91.0% to 101.3%. After oral administration, the peak plasma concentration of lobetyolin was obtained as 60.1 ng.mL-1 at 1.0 h. The proposed LC-MS/MS method could be applied to a pharmacokinetic study employing 66 samples from 6 Wistar rats.