Objective: To build an evaluation method for in vivo pharmacokinetic study on multicomponents in a complex system of traditional Chinese medicines (TCMs) in rats. Method: After mixed suspension of capsules with components from Hedyotis diffusa was orally administered to rats

blood samples were collected from eye of rats at different time points.Plasma samples were scanned by ultraviolet-visible spectrophotometer to calculate area under the absorbance-wavelength curve (AUAWC) and then produce total plasma concentration in rats at each time point.Pharmacokinetic parameters were calculated with DAS2.0 software and compared with data of every single component-quercetin

oleanolic acid and stigmasterol in plasma samples obtained by high performance liquid chromatography (HPLC)

in order to determine feasibility of the above two methods. Result: With method of AUAWC

mixed total concentration of capsules conformed to one-compartment model in rats

with Tmax at 0.5 h

Cmax of 2.85 mg · L-1

AUC0-∞ of 26.81 mg · L-1 · min-1.HPLC method also showed a one-compartment model for quercetin

oleanolic acid and stigmasterol

with Tmax at 1 h

Cmax of 0.17 mg · L-1

AUC0-∞ of 0.71 mg · L-1 ·min-1 for quercetin;Tmax at 0.5 h

Cmax of 0.69 mg · L-1

AUC0-∞ of 10.69 mg · L-1 · min-1 for oleanolic acid;Tmax at 0.5 h

Cmax of 3.84 mg · L-1

AUC0-∞ of 12.49 mg · L-1 · min-1 for stigmasterol

respectively. Conclusion: AUAWC can be used to study pharmacokinetics of capsules with components from H. diffusa in rats.Its combination with HPLC can better solve synchronous test for whole and individual components in TCM preparations with a better complementarity between them.