Determination of nifuratel in human plasma by HPLC and study on its pharmacokinetics.

A simple and sensitive reversed-phase high-performance liquid chromatography method using UV detection is established for the determination of nifuratel in human plasma and applied to a study of its pharmacokinetics. Plasma samples are extracted with ethyl acetate. A C(18) column and a mobile phase of 0.01 M (pH 7) phosphate buffer (KH(2)PO(4)) and acetonitrile (61:39, v/v) are used. Analysis is run at a flow rate of 1.0 mL/min with the detector operated at a wavelength of 367 nm. The calibration curve is linear over a concentration range of 0.2-40 ng/mL with a correlation coefficient of 0.9996. The limit of detection is 0.1 ng/mL. The mean absolute recovery value is greater than 80%. The intraday precision (relative standard deviation) ranges from 1.89% to 7.32%, and the interday precision ranges from 1.71% to 7.83%. The results show that the area under the plasma concentration-time curve, time to maximum observed plasma concentration, maximum concentration reached in the concentration profile, and elimination half-life between the testing tablets and reference tablets have no significant difference (P > 0.05). Relative bioavailability is 104.0% +/- 16.5%.