Determination of digoxin hydrolyzed products in digoxin tablet and in the medium after dissolution test by HPLC

A method for HPLC determination of digoxigenin (DO), digoxigenin monodigitoxoside(D1) and digoxigenin bisditoxoside (D2) in digoxin tablet was developed and applied to the determination of these digoxin hydrolyzed products in the chloroform extract of dissolution test solution of the tablet. Digoxin hydrolyzed products were separated at 40 °C on an Inertsil ODS column by using mixed solution of acetonitrile-methanol-water (11 : 7 : 35) as mobile phase, and were detected at 225 nm. Ethyl benzoate was used as an internal standard. In six brand of tablets, D0, D1 and D2 were found to be 0.131.84, 0.160.29 and 1.604.19 μg/tab., respectively. The chloroform extract of dissolution test solution was found to contain 42.546.4% D0, 17% D1, 20% D2 and 15.720.2% digoxin.