Pharmacokinetic Study of Ocotillol in Rats by LC-MS /MS / 中国药学杂志

ABSTRACT

OBJECTIVE: To develop an LC-MS /MS method for the quantitative analysis of ocotillol in rat plasma, and study the pharmacokinetic characteristics of ocotillol in rats after oral administration. METHODS: Ocotillol was extracted from plasma sample by protein precipitation. The concentration of ocotillol in plasma was determined by LC-MS/MS and the plasma concentration-time curve and main pharmacokinetic parameters were calculated after a single oral administration of ocotillol at 40 mg•kg-1 to SD rats. RESULTS: Excellent linearity was found between 10 - 240 ng•mL-1. Intra-and inter-day precision values (RSDs) of QC samples were both below 15% and the extraction recoveries of ocotillol from plasma were higher than 84.14%. Double peaks were observed in the mean plasma concentration versus time profile of ocotillol after oral administration. The main pharmacokinetic parameters of ocotillol were as follows the mean maximum plasma concentration (ρmax) was (156.60 ± 51.84) ng•mL-1 occurring at (0.83 ± 0.26) h post dose, the mean elimination half-time (t1/2) was (8.82 ± 7.56) h, and the mean area under the plasma concentration versus time curve (AUC0-t) was (687.15 ± 144.08) ng•h•mL-1. CONCLUSION: The current data shows that ocotillol is rapidly absorbed in rats after oral administration and slowly eliminated from circulatory blood system, with low plasma exposure. Enterohepatic circulation may contribute to the atypical drug absorption profiles.