Human Pharmacokinetics of Ephedrine and Pseudoephedrine in Mahuang Tang by GC-MS / 中药新药与临床药理

ABSTRACT

Objective To develop a gas chromatography-mass spectrometry (GC-MS) method for the determination of ephedrine (E) and pseudoephdrine (PE) and to study the pharmacokinetics features of E and PE in healthy human volunteers. Methods The serum concentrations of E and PE were measured by GC-MS. The pharmacokinetic parameters were computed by using WinNonlin program. Results A good linearity was obtained in E from 5 ng/mL to 1000 ng/mL (r2=0.9985) and in PE from 2.5 ng/mL to 500 ng/mL (r2=0.9994). The recoveries were in the range of 107.5 %to 96.2 %and 102.5 %to 93.9 %for E and PE respectively. The interday RSD and intraday RSD of E and PE were both less than 5 %. The E and PE plasma solution were steady within 60 days. Conclusion This GC-MS method is a accurate and reliable method for the determination of E and PE in human plasma.