Synonyms: 1,3'-Bipyridinium, 5'-(2-(4-((4-(2-(1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo(1,3'-bipyridinium)-5'-yl)diazenyl)benzoyl)amino)phenyl)diazenyl)-1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo-, 2-hydroxypropanoate (1:2);Pyridinium, 1,1'-((iminocarbonyl)bis(4,1-phenylene)bis(azo)bis(1,2-dihydro-6-hydroxy-4-methyl-2-oxo-3,5-pyridinediyl))bis(3-methyl-, bis(lactate);1,3'-Bipyridinium, 5'-((4-((4-((1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo(1,3'-bipyridinium)-5'-yl)azo)benzoyl)amino)phenyl)azo)-1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo-, salt with 2-hydroxypropanoic acid (1:2);3-methyl-1-[(5Z)-4-methyl-5-(2-{4-[(4-{(2Z)-2-[4-methyl-5-(3-methylpyridinium-1-yl)-2,6-dioxo-1,6-dihydropyridin-3(2H)-ylidene]hydrazinyl}benzoyl)amino]phenyl}hydrazinylidene)-2,6-dioxo-1,6-dihydropyridin-3(2H)-yl]pyridinium