Rapid Characterization of Impurity Profiles in Vancomycin Raw Material by Column-Switching LC/MSn / 中国药学杂志

ABSTRACT

OBJECTIVE: To characterize the impurity structures in vancomycin raw material. METHODS: Impurities were eluted gradiently on a Chromasil 100-5 C18(4.6 mm×250 mm, 5 μm) column, with triethylamine buffer solution (pH 3.2)-acetonitrile-tetrahydrofuran (92∶7∶1, V/V/V) as mobile phase A, and triethylamine buffer solution (pH 3.2)-acetonitrile-tetrahydrofuran (70∶29∶1, V/V/V) as mobile phase B. Stress tests were performed on the raw material to specify those impurities. By application of on-line LC/MSn method, the impurities were analyzed in positive mode and their structures were characterized based on the degradation mechanism and mass fragmentation regularity of sugar-lipopeptides. RESULTS: Totally 14 impurities were characterized in the raw material, seven of which were reported for the first time. The relationships between the chemical structures and chromatographic behaviors of vancomycin, demethylvancomycin and methylated vancomycin with their two β-isomers were summarized. CONCLUSION: The structures of related impurities in vancomycin raw material can be rapidly identified by on-line LC/MSn method together with stress degradation experiments.