dipotassium 3-[3-carbamoyl-1-ethyl-1,2-dihydro-6-hydroxy-4-methyl-2-oxo-5-pyridylazo]phenylphosphonate;1-Ethyl-1,2-dihydro-6-hydroxy-4-methyl-2-oxo-5-[[3-[bis(potassiooxy)phosphinyl]phenyl]azo]-3-pyridinecarboxamide;Phosphonic acid,P-[3-[2-[5-(aminocarbonyl)-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-3-pyridinyl]diazenyl]phenyl]-,potassium salt (1:2)