LC-MS/MS Determination of Crotonoside in Rat Plasma and Application to Pharmacokinetic Study

Crotonoside, a main bioactive component in Croton tiglium L., exhibits promising antitumor and immunological activities. This study developed and validated a rapid, sensitive LC-MS/MS method for the quantification of crotonoside in rat plasma. The mobile phase was 0.1% formic acid aqueous solution-acetonitrile (50:50, v/v) with a flow rate of 0.2 mL/min. Rats were randomly divided into two groups for intragastric and intravenous administration, respectively. Protein precipitation by acetonitrile was used to separate crotonoside from the plasma samples. The samples were analyzed using a validated method. Method validation included linearity, precision, accuracy, recovery, matrix effect, and sample stability. The linear range of crotonoside was 20-10,000 ng/mL. Recoveries ranged 93.5%-101.7% with precision (RSD ≤ 7.7%). Matrix effects and stability were acceptable. Crotonoside pharmacokinetics after intragastric administration were as follows: maximum drug concentration (C_max), 2.35 ± 2.71 μg/mL; area under drug concentration time curve (AUC_0-∞), 2.30 ± 1.21 μg*h/mL; and half-life (t_1/2), 6.33 ± 11.24 h. For intravenous administration, values were C_max, 5.86 ± 0.99 μg/mL; AUC_0-∞, 3.13 ± 1.84 μg*h/mL; and t_1/2, 5.25 ± 2.34 h. Oral bioavailability was 36.7%. The assay has been successfully applied to the pharmacokinetic study of crotonoside in rats.