The Effect On Pharmacokinetics Of The Active Compounds In Human Plasma Among Herbs In Mahuang Decoction

To investigate the composition principles in compound prescription of the Chinese traditional medicine, this paper expounds the relationship amongthe chief, adjuvant, assistant, and courier herbs in Ma-Huang Decoction (MHD). The investigation is conducted from the aspect of whether the composition affects the internal process of the main active components of the dominant drug. By using the pharmacokinetic method, the investigation, consequently, makes it possible to clarify the effect and status of the other drugs in the description, and leads to the further research.Objective: To establish a method to determine the quantities of Ephedrine(E) and Pseudo-ephedrine(PE) in the plasma, and study the mutative rules of the pharmacokinetic parameters of the E and PE in different composition.Method : 1. A selective Gas-Chromatographic method with Mass Spectrometry (GC-MS) for the simultaneous confirmation and quantification of E and PE was developed in plasma and evaluated by systems analysis.2. Orthogonal design was used to determine 8 compositions from MHD. The healthy men were divided into groups in random, each group concluding six men. After taking the medicine orally, vena blood would be taken out at different time. Determining E and PE in plasma and plotting the Concentration-Time curve.3. The pharmacokinetic parameters of each composition were calculated by WinNonlin4.0.1.4. The statistical analysis of the pharmacokinetic parameters were proceeded by SPSS 10.0.Results:1. The determination of the E and PE in human plasma is exact and reliable by GC-MS.2. All Concentration-Time curve were adequately modeled by one compartment, first order absorption model, no lag time.3. Some parameters of E and PE showed significant variance (P<0.05) in different compositions.4. The statistic results showed interactions between herbs in MHD(P<0.05).Conclusion:The adjuvant, assistant and courier herbs of MHD have extent effect to the pharmacokinetic parameters of the chief herb. The results suggest that each herbs would have different status and effects in the prescription. The conclusion is coinciding to the composition principles in compound prescription of the Chinese traditional medicine and the results provide certain experimental data for further research.