[Study on separation of epirubicin and doxorubicin isomers by displacement chromatography]

Displacement chromatography was successfully used to separate, at the preparative scale, a binary isomer mixture of epirubicin and doxorubicin, which are anthracycline antitumor antibiotics, on an analytical column (Kromasil KR100-10C18 column, 250 mm x 4.6 mm i.d., 10 microm). Displacement parameters such as the type and the concentration of displacer, the composition and the flow-rate of mobile phase were investigated. The displacer employed was 30 g/L benzethonium chloride. The flow-rate was 0.2 mL/min. Loading of feed at lower initial organic level of mobile phase coupled with displacement at higher organic level was found to give efficient separation. The binary isomer mixture of 30 mg was separated on the analytical column. The results have indicated that displacement mode had high efficiency, greatly reduced solvent consumption in the process of purification, and offered the possibility of both high resolution and high loading. It has also demonstrated again that high performance displacement chromatography is one of the effective methods for the purification of therapeutic compounds in industrial processes.