Objective: To compare the contents of ferulic acid and paeoniflorin between traditional slice decoction and dispensing granule decoction of Siwu Tang.
Methods: A HPLC method detected ferulic acid and paeoniflorin with Diamonsil C18 (4.6 mm x 250 mm, 5 microm) column. The column temperature was setup at 35 degrees C and the flow rate was 1 ml/min. The mobile phase for ferulic acid was a mixed solution of MeOH-H2O-0.05% H3PO4 (40:50:10) and the wavelength was 327 nm, while for paeoniflorin was a mixed solution of CH3CN-H2O-0.05% H3PO4 (16:74:10) and the wavelength was 230 nm.
Results: The contents of ferulic acid and paeoniflorin in the dispensing granule decoction were 8.91 mg/dose and 83.57 mg/dose, in the traditional slice decoction were 8. 90 mg/dose and 78. 51 mg/dose, and in the dispensing granule decoction from different factories were from 3.36 to 7.67 mg/dose and from 48.13 to 67.52 mg/dose.
Conclusion: The HPLC chromatotograms are similar in the two forms of Siwu Tang and the contents of ferulic acid and paeoniflorin are equivalent, but discrepant in the dispensing granule decoction from different factories.