Pharmacokinetics of triptolide. Development and application of a high performance liquid chromatographic method for quantitation of triptolide in plasma
Yp. Mao et al., Pharmacokinetics of triptolide. Development and application of a high performance liquid chromatographic method for quantitation of triptolide in plasma, J LIQ CHR R, 22(9), 1999, pp. 1355-1366
In order to evaluate the bioavailability and study the pharmacokinetics of
triptolide, an HPLC method was developed for the quantitative determination
of this diterpenoid in plasma. The procedure for the plasma assay employed
liquid - liquid extraction with chloroform followed by high speed centrifu
gation. The UV absorbance of the effluent was monitored at 218 nm. An inter
nal standard (acetophenone) was used to calibrate injection and instrument
reaction errors. The proposed methodology is sensitive, rapid, and reproduc
ible. The limit of quantitation is 0.005 mg/L in plasma (0.05 mg /L in fina
l solution) and a linear range of determination is observed over the concen
tration of 0.05 mg/L to 30 mg/L. The inter- and intraday coefficients of va
riation for the assay of triptolide in plasma were < 16.82% at low concentr
ation (0.005-0.076 mg/L) and < 8.05% at high concentration (0.152-5.000 mg/
L). Recovery of triptolide in plasma is greater than 96.72%.
Triptolide was stable in plasma during 30 days of storage at 80 degrees C,
whereas degradation products appeared within 4 hours when it was dissolved
in methanol at room temperature. The method was employed to determine the p
harmacokinetics of triptolide in rat plasma.
After oral administration of a single dose of 840 mu g/kg, triptolide was f
ound to reach a peak concentration (Cmax) of 0.210 mu g/mL in 19.5 min. (Tm
ax). The AUC was 157.28 mu g and the elimination half time was 50.60 min..