Quality standard study on Tibetan medicine Gentianae Szechenyii Flos

In order to efficiently control the quality of the Tibetan medicine Gentianae Szechenyii Flos, the quality standard was established in this study. The tests of water content, total ash and ethanol-soluble extractives of the crude drugs were carried out based on the methods recorded in appendix of Chinese Pharmacopeia (2010 edition, volume 1). The TLC method was established by using reference drug and gentiournoside A as reference substance, and a mixture of ethyl acetate-methanol-water-formic acid (7: 1.5: 1: 0.2) as the developing solvent system on silica gel G TLC plate. The content of gentiournoside A was assayed by HPLC on a Ultimate XB-C18 (4.6 mm x 250 mm, 5 μm) column, using methanol-water (0.02% phosphoric acid) (52:48) as the mobile phase at a flow rate of 1.0 mL x min(-1). The column temperature is 25 degrees C and the detection wavelength is at 240 nm. As a result, gentiournoside A and the other constituents were separated and presented the same fluorescence light comparing with the reference substance on TLC detected under the UV light(366 nm). The methodology validation for the assay of gentiournoside A showed that it was in a good linear correlation in the range of 10.01-400.32 mg x L(-1) with the regression equation of Y = 1 539.5X - 33.339 (r = 0.999 7), and the average recovery was 99.68% (RSD 1.92%). The mass fractions of gentiournoside A, water content, ethanol-soluble extractives of 19 batches samples were varied in the ranges of 14.48-31.51 mg x g(-1), 11.25% -12.74% and 24.21% - 31.60%, respectively, and total ash was 4.64% - 6.12% detected from 10 batches samples. The recommended standards of quantitative indexes are that the mass fractions of gentiournoside A and extractives are not less than 15.0 mg x g(-1) (1.5%) and 21.0%, respectively; the water and total ash are not more than 13.0% and 6.0%, respectively.