Determination and pharmacokinetic study of taxifolin in rabbit plasma by high-performance liquid chromatography.

Taxifolin has been widely used in the treatment of cerebral infarction and sequelae, cerebral thrombus, coronary heart disease and angina pectoris. A reliable sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method with UV detection for the pharmacokinetic study of taxifolin in rabbit plasma after enzymatic hydrolysis was developed and validated for the first time. Taxifolin, with biochanin A as the internal standard, was extracted from plasma samples by liquid/liquid extraction after hydrolysis with beta-glucuronidase and sulfatase. Chromatographic separation was conducted on a Luna C18 column (4.6 mm x 150 mm, 5 microm particle size) and pre-column (2.0 mm, the same sorbent). Two-step linear gradient elution with acetonitrile and 0.03% water solution of trifluoroacetic acid as mobile phase at a flow rate of 1.0 ml/min was used. The UV detector is set at 290 nm. The elution time for taxifolin and biochanin A was approximately 7.9 and 18.3 min, respectively. The calibration curve of taxifolin was linear (r > 0.9997) over the range of 0.03-5.0 microg/ml in rabbit plasma. The limit of detection (LOD) and limit of quantification (LOQ) for taxifolin were 0.03 and 0.11 microg/ml, respectively. The present method was successfully applied for the estimation of the pharmacokinetic parameters of taxifolin following intravenous and oral administration of lipid solution to rabbits. The absolute bioavailability of taxifolin after oral administration of lipid solution was 36%.