Pharmacokinetics of ephedrine gels and extractum ephedrae gels in guinea pig / 中成药

ABSTRACT

AIM: To establish a method to determine the serum concentration of ephedrine,and to study its pharmacokinefics in guinea pig. METHODS: The serum concentration of ephedrine gels transdermal administration in guinea pig were determined by HPLC and pharmacokinetic parameters were calculated by computer.(RESULTS:)The calibration curve was linear in the range of 0.5～2 ?g with r=0.998 0.The limit of identification was 0.02 ?g/mL.The pharmacokinetics behavior of ephedrine showed one order absorption.The main parameters after adminstrition of ephedrine gels and extractum ephedrae gels were as follows:t_(1/2)k_a were 1.362 1 and(l.541 8),t_(1/2)k_e were 2.627 4 and 3.262 2 h,T_(max) were 3.124 3 and 3.440 9 h,C_(max) were 0.115 6 and 0.081 0 ?g/mL,AUC were(0.081 0) and 0.741 5 ?g?h/mL. CONCLUSION: Ephedrine shows a fast rate of absorption in guinea pig,serum concentration of ephedrine is stable and lasting potency,and indicates the reason of transdennal administration of Herba Ephedrae preparation.