Pharmacokinetic of 5 components after oral administration of Fructus Forsythiae by HPLC-MS/MS and the effects of harvest time and administration times

• 5 flavonoids and 4 lignans of Fructus Forsythiae were determined by LC-MS/MS.
• The lower limits of quantitation of 9 typical components were lower than 4 ng mL−1.
• Harvest time effect the content and the bioavailability of active components.
• Administration times could influence the bioavailability of active components.

The unripe Fructus Forsythiae (Qingqiao) and ripe Fructus Forsythiae (Laoqiao) are two types of the clinical forms of commercial fructus of Forsythia suspensa(Thunb.) Vahl. There is limited information available for differences in pharmacokinetic properties of active components between unripe and ripe Fructus Forsythiae in vivo. A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the simultaneous determination of 9 typical components in rat plasma. The separation of nine analytes was performed on an Eclipse plus C18 (4.6 mm × 100 mm, 1.8 μm) column with the mobile phases consisted of a mixture of 0.1% formic acid in water and acetonitrile. Method validation indicated that the developed method was rapid, specific and sensitive. It was found that the AUC(0–24h) of 5 ingredients (forsythoside A, rutin, phillyrin, isorhamnetin and quercetin) in rats after single orally administrated unripe Fructus Forsythiae also had significant differences compared with those after single dose oral administration of ripe Fructus Forsythiae extract. The systemic exposure of 5 ingredients after multiple oral administration of Fructus Forsythiae extract had significantly increased than those after single oral administration. The results indicated that harvest time is not only effects the contents but the bioavailability of active components of Fructus Forsythiae, which suggests that the rate and extent of drug metabolism were altered when the clinical forms of commercial Fructus Forsythiae with different harvest time. The administration times could influence the bioavailability of active components of Fructus Forsythiae.