HPLC Determination of 18-isomer of Diammonium Glycyrrhetate for Injection and Its Ratio Evaluation

OBJECTIVE 　A HPLC method was established for the determination of 18-epimer of diammonium glycyrrhetate for injection, and its ratio in 55 batches products was evaluated. METHODS A C₁₈ column was used as the stationary phase with acetonitrile-phosphate buffering solutoion (pH 7.0) (20∶80) as the mobile phase, flow rate was 1.0 mL·min^-1, and the detection wavelength was at 252 nm. RESULTS 　The separation of 18-α and 18-β GL was good, and the ratios of α/β were different between products. CONCLUSION The method can accurately determine ratios of α/β GL in diammonium glycyrrhetate for injection, its ratio may be related with its manufacturing process.