N-[2-[4-(Aminosulfonyl)phenyl]ethyl]-5-methyl-2-pyrazinecarboxamide sodium salt ; N-[2-[4-(aminosulfonyl)phenyl]ethyl]-5-methyl-Pyrazinecarboxamide monosodium salt ; sodium 5-methyl-N-[2-(4-sulphamoylphenyl)ethyl]pyrazinecarboxamidate ; Glipizide EP Impurity A (Sodium Salt)