On the Hydration States of 3-(4-Carbamoyl-1-pyridiniomethyl)-7β-(D-α-sulfophenylacetoamido)-ceph-3-em-4-carboxylate Monosodium Salt (Cefsulodin Sodium, SCE-129)

3-(4-Carbamoyl-1-pyridiniomethyl)-7β-(D-α-sulfophenylacetamido)-ceph-3-em-4-carboxylate monosodium (cefsulodin sodium) was found to exist in crystals in three states of hydration. The hexahydrate was obtained by crystallization from aqueous ethanol and was dehydrated to the dihydrate and anhydrate. The properties of the crystal water in cefsulodin sodium were investigated.