Patent Blue V sodiumProduct ingredient for Patent Blue

Patent blue is aniline dye and it is one of the most common dyes used.¹ It is a sodium or calcium salt of diethylammonium hydroxide inner salt.² It has the chemical designation of (4-(alpha-(p-(diethylamino)phenyl)-2,4-disulfobenzylidene)-2,5-cyclohexadiene-1-ylidene)diethylammonium hydroxide. Patent blue was developed by Guerbet and approved by Health Canada on December 31, 1979.⁵ The isomer isosulphan is used in the United States for the same indications than patent blue.²