21 CFR 74.1328 - D&C Red No. 28.
(1) The color additive D&C Red No. 28 is principally the disodium salt of 2′,4′,5′,7′-tetrabromo-4,5,6,7-tetrachlorofluorescein (CAS Reg. No. 18472-87-2) formed by alkaline hydrolysis of the parent tetrabromotetrachlorofluorescein.
(2) Color additive mixtures for drug use made with D&C Red No. 28 may contain only those diluents that are suitable and that are listed in part 73 of this chapter as safe for use in color additive mixtures for coloring drugs.
(b)Specifications. D&C Red No. 28 shall conform to the following specifications and shall be free from impurities other than those named to the extent that such impurities may be avoided by current good manufacturing practice:
(c)Uses and restrictions. D&C Red No. 28 may be safely used for coloring drugs generally in amounts consistent with current good manufacturing practice.