Background: Cefoselis sulfate similarly to other 4th generation cephalosporin is vulnerable for
degradation in aqueous solution.
Methods: For identification cefoselis sulfate degradation products chromatographic system consisting of
Kinetex, C18, 100A, 100 × 2.1 mm, particle size 5 µm column, mobile phase: acetonitrile – 0.1% formic
acid (5:95 V/V) and a hybrid ESI-Q-TOF mass spectrometer was used.
Results: Masses of degradation products with high accuracy (0.09 - 4.64 ppm) were found. Following formulas were obtained: 128.08243 (C5H10N3O), 243.05471 (C8H10N4O3S), 370.06338
(C13H16N5O4S2), 414.05324 (C14H16N5O6S2), 451.13191 (C17H23N8O3S2), 479.12777 (C18H22N8O4S2)
and 523.11859 (C19H23N8O6S2) - cefoselis sulfate.
Conclusions: Five previously unknown and one known impurities of CSS were identified by HPLCMS/
MS Degradation pathways of cefoselis sulfate in aqueous solutions were suggested.