Determination and pharmacokinetic study of guaiol in rat plasma by gas chromatography–mass spectrometry with selected ion monitoring

Abstract Guaiol has been used for thousands of years as a traditional Uygur medicine and is the primary active component found in Ferula ferulaeoides (Steud.) Korov ( F. ferulaeoides ). In our present study, a rapid, selective, and sensitive method of monitoring selected ions was established based on gas chromatography-mass spectrometry. This method was optimized for the quantification and pharmacokinetic analysis of guaiol in rat plasma following oral administration of chloroform extract from Ferula ferulaeoides . Plasma was extracted using liquid-liquid extraction with ethyl acetate and was analyzed on a HP-5MS column (30 m × 250 μm × 0.25 μm) with a mass selective detector. Detection was carried out under selected ion monitoring mode, and three selected ion monitoring ions ( m / z 59.1, 107.1, and 161.1 for guaiol) were used for the quantitative determination of that under investigation. The assay demonstrated excellent linearity in the range of 1–200 ng/mL ( r  = 0.9993, n  = 8) in the case of guaiol measured in rat plasma. The limit of detection and the limit of quantification for guaiol in rat plasma were found to be 0.25 ng/mL and 1 ng/mL, respectively. Intra-day and inter-day precisions were expressed as the relative standard deviation for the method and were in the range of 97.49%–106.16% and 97.04%–105.91%, respectively. Extraction efficiencies were all determined to be >90%, and recoveries were ranged from 91.25% to 96.24%. This method has been successfully applied for the pharmacokinetic evaluation of chloroform extract isolated from F. ferulaeoides following a single oral administration dose (157.5 mg/kg) in rats. The guaiol pharmacokinetic study demonstrated that the half-life of guaiol was 9.18 ± 3.75 h, the mean residence time was 9.07 ± 3.86 h, the maximum guaiol concentration in the plasma was 28.63 ± 6.82 ng/mL, and the maximum time guaiol was in the plasma was 0.50 h.