Indigotindisulfonate sodiumProduct ingredient for Indigotindisulfonic acid

Indigotindisulfonic acid is a blue-colored dye with a variety of uses.^2,3,4,12 Its salt form, indigotindisulfonate sodium, is also known as indigo carmine, indigotine or FD&C Blue #2. This compound is an acid-base indicator and is used in the production of food colorants and pH tests.⁷ Indigotindisulfonic acid is used in clinical medicine to determine patency of the urinary collecting system, and to assist in specific surgical procedures such as cystourethroscopy.^2,3,4 In 2022, the FDA approved the intravenous use of indigotindisulfonate sodium to aid in visualizing ureter integrity in cystoscopic assessments.¹⁰