Pharmacokinetics of patchouli alcohol and patchouli alcohol in patchouli oil after iv administrated to rats

AimTo develop a capillary gas chromatographic method for the determination and pharmacokinetic study of patchouli alcohol in rat plasma after iv administration. MethodsThe drug was extracted with ethyl acetate. Eugenol was used as internal standard. The separation was carried out on a HP-5MS quartz capillary column, with high-purity nitrogen as carrier gas and flame ionization detector (FID) as detector. The column temperature was maintained at 80 ℃ for 1 min and then programmed to 200 ℃ at a rate of 15 ℃·min^-1; it was held at 200 ℃ for 1 min, and then programmed to 290 ℃ at a rate of 60 ℃·min^-1; the final temperature was held for 1 min. The temperature of both injector and detector was set at 290 ℃. ResultsThe standard curve was linear from 25 to 5 000 μg·L^-1 in rat plasma. The recovery of this method was from 90.0% to 110.0% with satisfactory relative standard deviation (RSD) less than 10.0%. The pharmacokinetic parameters demonstrated patchouli alcohol were consistent with the two-compartment open model and showed linear pharmacokinetics. The t_1/2β, AUC and MRT of patchouli alcohol in patchouli oil were all higher than that of patchouli alcohol. Conclusion This method is quick, precise and reliable. The pharmacokinetics of patchouli alcohol is different from that of patchouli alcohol in patchouli oil.