Objective:To study the phamacokinetics of Nalmefene hydrochloride. Methods:30 healthy Chinese volunteers were assigned to 3 groups according to randomized design

and each group were given respectively a single intravenous administration dose of 0.5 mg

1mg and 2mg of Nalmefene hydrochloride. The electrospray ionization positive selected reaction monitoring detections for Nalmefene hydrochloride and allyln-oroxymorphone (the internal standard) in the plasma and in the urine were used. The pharmaceutical parameters were calculated by 3P87 software. Results: The limit of the detection for Nalmefene hydrochloride was 0.0008 ng/ml in plasma and 0.0003 ng/ml in urine. There were good linear relationship range from 0.04 to 625ng/ml in plasma and 0.2 to 625 ng/ml in the urine. The variation coefficient in day and days

and the recoveries fitted the clinical pharmacokinetic study requirements. After a single intravenous administration of 0.5 mg

1mg

and 2mg of Na-lmefene hydrochloride

the obtained pharmacokinetic parameters were respectively as follows:Cmax were(1.74±0.48)μg/L

(4.17±1.08) μg/L

(7.88±2.89) μg/L;t1/2β were(12.83±3.98) h

(12.6±6.4) h

(10.58±3.74) h;V were (3.45±0.16) L/kg;(4.11±0.0716)L/kg、(4.25±0.56)L/kg;CL were (0.81±0.11) L/(h·kg)

(0.85±0.15)L/(h·kg)

(0.87±0.11) L/(h·kg);AUC0-∞ were (21.62±9.34) (ng/L)*h

(24.89±8.52) (ng/L)*h

(35±11.2) ng/L)*h;the urine accumulatived exc-retory rate were (78±21)%

(71±29)%

(78±19)%. Conclusion: The determination method for Nalmefene hydro-chloride in the plasma and in the urine by the electrosprayionization positive selected reaction monitoring detections is exclusive

accurate

sensitive and suitable. Pharmacokinetic characteristics in 3 groups of human treated with intravenous administration were described by a two-compartment model. The pharmaceutical characteristics of doxycycline hydrochloride in human body were linear in the range of 0.5~2.0 mg.