Objective: To establish a method for determination of rhein in rats plasma by solid-phase extraction-high performance liquid chromatography

and study the pharmacokinetic. Method: SD rats were i.g with rhein after a single dose

blood samples were collected at time intervals. The plasma concentrations of sample in rats were assayed by SPE. The plasma concentrations of rhein were determined by HPLC method and internal standard method. Rhein was eluted on a Venusil XBP C18(L)(4.6 mm×250 mm

5 μm) column

using a mobile phase of methanol-0.1% acetic acid water (75∶25); and the column temperature was controlled at 30 ℃

the UV detector was operated at 254 nm. The pharmacokinetic parameters were calculated by the software of DAS 2.0. Result: In rat plasma

rhein was linear in the range of 0.019 2 to 11.72 mg ·L-1 (R2=0.999 1). Detection limit (LOD) and quantification limit (LOQ) were 0.009 6 and 0.019 2 mg ·L-1 respectively. The recovery of rhein from plasma was larger than 80%

and RSDs of intra-day and inter-day were less than 6%. Conclusion: The concentration-time curve of rhein was shown to fit two compartment models. This method is accurate

precise and specific

and can be applied to determine the pharmacokinetic of rhein.