Mezlocillin Sodium, 3,3-Dimethyl-6-[[2-[(3-methylsulfonyl-2-oxo-imidazolidin-1-yl)carbonylamino]-2-phenyl-acetyl]amino]-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid sodium salt, Sodium 6beta-{(2R)-2-[3-(methanesulfonyl)-2-oxoimidazolidine-1-carboxamido]-2-phenylacetamido}penicillanate, Sodium (2S,5R,6R)-3,3-dimethyl-6-{[(2R)-2-({[3-(methylsulfonyl)-2-oxoimidazolidin-1-yl]carbonyl}amino)-2-phenylacetyl]amino}-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate, Sodium 6beta-{(2R)-2-[3-(methanesulfonyl)-2-oxoimidazolidine-1-carboxamido]-2-phenylacetamido}-2,2-dimethylpenam-3alpha-carboxylate