Identification of major impurities in doxofylline injection / 中国药学杂志

OBJECTIVE: To identify the structures of the major impurities of doxofylline injection. METHODS: HPLC-QTOF-MS was adopted to analyze the structures of two major impurities; the impurities were further separated and prepared by prep-HPLC and the structures were elucidated by NMR spectral data. RESULTS: The two major impurities were elucidated as 7-(2', 2'-dihydroxy ethyl) theophylline and 9-(1, 3-dioxolan-2-ylmethyl) theophylline. CONCLUSION: The two major impurities are thermo-degradation impurity and process related impurity respectively. This study provides reference for the improvement of quality control and process optimization of doxofylline injection.