Abstract: Objective To develop an HPLC method to determine the contents of free anthraquinone in Polygonum multiflorum and Polygoni multiflori radix praeparata of Runzao Zhiyang capsule. Methods Eclipse XDB-C18(5μm, 150mm×4.6mm) was adopted. Methods was used as mobile phase A and 0.1% phosphoric acid was used as mobile phase B with gradient elution. The detection wavelength was 254 nm. Results The linear range of emodin was 0.0514~1.3878μg, the recovery(n=6) of this method was 103.8% and RSD was 1.1%; The linear range of physcion was 0.017216~0.464832μg, the recovery(n=6) of this method was 102.7% and RSD was 1.4%. Conclusion The method is convenient, accurate and can be applied in quantitative determination of the drug.

Key words: HPLC, Runzao Zhiyang capsule, free anthraquinone, determination