Objective: To study the pharmacokinetics of rhein from Sanhuang Xiexin Decoction in rats

and compare the pharmacokinetics of rhein after ig administration of Sanhuang Xiexin Decoction and Radix et Rhiyoma Rhei.Methods: Wistar rats were given(ig) a single dose of Sanhuang Xiexin Decoction 20 g·kg-1 or Radix et Rhiyoma Rhei 10 g·kg-1.The plasma concentration of Rhein was measured by high performance liquid chromatography after extracted with perchloric acid and ether.An HPLC method was established with(SHIMADZU) VP-ODS column(150 mm×4.6 mm

5 μm)

the mobile phase was methanol-water-0.2% phosphoric acid(82∶18)

the flow rate was 1.0 mL·min-1 and a detection wavelength was 245 nm.Pharmacokinetic parameters were determined from the plasma concentration-time data with the software 3P97.Results: The concentration-time curves of rhein fitted well into two-compartment models in rats.The elimination T1/2 of rhein in Sanhuang Xiexin Decoction and Radix et Rhiyoma Rhei were(18.26±4.72) h and(10.69±2.19) h respectively.Significant difference was found between the two groups.There existed significant(P<0.05) differences in plasma concentration and AUC of rhein between Sanhuang Xiexin Decoction and Radix et Rhiyoma Rhei.The values of normalized AUC by dose of rhein from Sanhuang Xiexin Decoction and Radix et Rhiyoma Rhei were(9.05±1.49)(μg·mL-1)·h and(6.87±1.60)(μg·mL-1)·h respectively.The values of normalized Cmax by dose of rhein were(0.82±0.06)μg·mL-1 and(0.68±0.04)μg·mL-1.Conclusions: The compound compatibility of the decoction promoted the absorption of rhein.It indicated that there is rationality in the compatibility of Sanhuang Xiexin Decoction.