Cefuroxime acid & sodium

Cefuroxime acid:
Molecular formula: C₁₆H₁₆N₄O₈S
Exact Mass: 424.07
Molecular weight: 424.39
C, 45.28; H, 3.80; N, 13.20; O, 30.16; S, 7.56
Chemical structure:

Cefuroxime sodium (sterile):

Molecular formula: C₁₆H₁₅N₄NaO₈S
Exact Mass: 446.05
Molecular weight: 446.37
C, 43.05; H, 3.39; N, 12.55; Na, 5.15; O, 28.67; S, 7.18
Chemical structure: