Determination of indigo and indirubin in Keyin Granule by RP-HPLC

Objective To determine the contents of indigo and indirubin in Keyin Granule.Methods The contents of indigo and indirubin were determined by HPLC.The chromatographic column was Phenomenex C18(250 mm×4.6 mm,5 μm),the mobile phase was methanol-water(80∶20,V/V),the flow rate was 1.0 mL/min and the temperature of column was 30℃ with detection wavelength of 287 nm for indigo and 292 nm for indirubin.Results The linear correlation of the indigo was in the range of 0.329-32.900 μg/mL [Y = 56.94C-1.749(r = 0.999 8)] and the recovery was 99.89% with RSD of 1.00%(n = 5).The linear correlation of the indirubin was in the range of 0.390-39.000 μg/mL [Y = 119.1C+19.71(r = 0.999 9)] and the recovery was 99.18% with RSD of 0.48%(n = 5).Conclusion The method can be applied to determine the contents of indigo and indirubin in Keyin Granule.It can ensure the stability of the quality control of Keyin Granule.