[Pharmacokinetics and disposition of vinpocetine in rats].
A reverse-phase HPLC method for determination of vinpocetine in biological samples was developed. The method was simple, highly specific and accurate. After i.v. administration of vinpocetine in rats, the plasma concentration-time curves of vinpocetine was found to be fitted to a two-compartment open model. Dosing 5 and 10 mg.kg-1 vinpocetine in rats, the elimination of the drug from plasma accorded with linear kinetics and the elimination half-lives were shown to be 1.76 +/- 0.27 h. The volumes of distribution were 7.30 +/- 0.49 L.kg-1 (5 mg.kg-1) and 6.07 +/- 0.67 L.kg-1 (10 mg.kg-1) respectively. The drug levels were high in the lung, spleen, liver and kidney, moderate in brain, fat and testis and low in heart, muscle and blood. Our results demonstrate that vinpocetine was eliminated in a rapid rate and distributed widely in the body. The bioavailability of vinpocetine after ig administration was 54.54% in rats. A small amount of unchanged vinpocetine was detected in urine, feces and bile after i.v. and ig administration.