Background: Fraxetin is mainly an active ingredient of Fraxini Cortex which is an important
and traditional Chinese medicine for clinical applications, has heat-clearing, dispelling dampness, antitussive
and anti-asthmatic effects. Fraxetin has a variety of pharmacological activities.
Method: The chromatographic separation was carried out on a Zorbax Eclipse XDB C18 column. The
mobile phase consisted of acetonitrile (0.1 % formic acid) and ammonium acetate (0.1 % formic acid).
Samples were prepared with protein precipitation.
Result: The method had good linearity within 10 - 2500 ng/mL. Both intra- and inter-assay precisions
were acceptable and ≤ 8.5 %. Extraction recovery was 75.9 - 89.5 %, and the lower limit of quantification
for fraxetin was 10 ng/mL. This proposed method was successfully used to study the pharmacokinetic
and bioavailability of fraxetin after 5 and 25 mg/kg fraxetin were administered to rats via intravenous
and oral routes, respectively. The half-life (t1/2) of fraxetin for i.v was (3.86 ± 0.65) h. The t1/2 of
fraxetin for p.o was (4.41 ± 1.79) h. The bioavailability of fraxetin is 12.6%.
Conclusion: The results provided some useful information for the future development and clinical
medication of fraxetin.