Objective: To establish an HPLC method for the determination of tetrahydropalmatine in Xiaoheling capsule. Method: The HPLC separation was performed on C18 column (4.6 mm×150 mm

5 μm) with mobile phase consisted of acetonitrile -2% acetic acid solution (ajusted pH to 5.0 using triethylamine) (25 ∶75); The detective wavelength was set at 280 nm with a flow rate of 1 mL ·min-1and the column temperature was set at 30 ℃. Result : Corydalis was linear in the range of 44.68-357.44 mg ·L-1 with coefficient 0.999 9. Average recovery was 101.10% with RSD 2.42% (n=5). Conclusion : The method was simple

rapid and accurate

and applicable for the quality control of Xiaoheling capsule.