Objective   To propose a method for the determination of droxidopa concentration in human plasma by HPLC method for the study of the pharmacokinetics of droxidopa.    Methods   After a single oral dose of 200 mg droxidopa capsule was administered to 12 healthy Chinese male volunteers

we used perchloric acid to precipitate proteinum and then determined the droxidopa concentration in plasma by HPLC. The pharmacokinetic parameters of droxidopa were calculated by 3P87 software.    Results   The linear range was 0.025-2 μg/ml. Pharmacokinetic parameters were: T

1/2

(108.50±30.78)min

AUC (185.74±26.41) μg·ml

-1

·min

-1

CL (1.08±0.08)ml/

min

T

max

(99.90±10.05)min

C

max

(0.74±0.08)μg/ml. At 10 h after administration

droxidopa was eliminated from the blood almost completely.    Conclusion   The method we proposed is sensitive

reproducible

and easy to operate. Pharmacokinetics of droxidopa in vivo is fitted to two-compartment model.