[Pharmacokinetics study on costunolide and dehydrocostuslactone after administration of traditional Chinese medicine Weichang'an pills].

A HPLC-MS/MS multiple-reaction monitoring (MRM) quantitative analysis was made to establish a determination method for drug concentrations of costunolide (Co) and dehydrocostuslactone (De) in blood samples in the positive ion mode, with diazepam as the internal standard substance, in order to study the pharmacokinetic process of sesquiterpene lactones costunolide and dehydrocostuslactone after the oral administration of Weichang'an pills, and provide an theoretical basis for further studies on the substance basis for the anti-diarrhea effect of Weichang'an pills. In the blood samples, Co and De showed a good linearity within concentration ranges 0.700 0-769.7, 2.510-956.0 μg x L(-1), respectively. The results of precision, stability and recovery experiences proved the stability and reliability of the plasma concentration determination method. After the oral administration, the concentrations of Co and De in plasma increased with the increase in dose, with T(max) between 10.65-12.98 h, indicating a long time to reach peak plasma concentrations; C(max) of costunolide and dehydrocostuslactone ranged between 3.750-5.450,15.34-44.52 μg x L(-1), respectively. The in vivo adsorption of Co and De conformed to the one-compartment model, with a longer time to attain the peak plasma concentrations. These results provided an experimental basis for revealing the active substance basis and clinical medication of Weichang'an pills.