[Code of Federal Regulations]
 [Title 21, Volume 1]
 [Revised as of April 1, 2002]
 From the U.S. Government Printing Office via GPO Access
 [CITE: 21CFR74.1104]
 
 [Page 398-399]
 
                         TITLE 21--FOOD AND DRUGS
 
 CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                                 SERVICES
 
 PART 74--LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION--Table of Contents
 
                             Subpart B--Drugs
 
 Sec. 74.1104  D&C Blue No. 4.
 
     (a) Identity. (1) The color additive D&C Blue No. 4 is principally
 the diammonium salt of ethyl[4-[p[ethyl(m- sulfobenzyl)ami-no]-
 <greek-a>-(o- sulfophenyl)benzylidene]-2,5-cyclo-hexadien-1-ylidene] (m-
 sulfobenzyl) ammonium hydroxide inner salt with smaller amounts of the
 isomeric diammonium salts of ethyl [4-[p-[ethyl(p- sulfobenzyl) amino]-
 <greek-a>-(o- sulfophenyl) benzylidene]-2,5-cyclohexadien - 1-ylidene](p-
 sulfobenzyl) ammonium hydroxide inner salt and ethyl[4-[p-[ethyl (o-
 sulfobenzyl)amino]-<greek-a>-(o- sulfophenyl) benzylidene]-2,5-
 cyclohexadien-1-ylidene] (o- sulfobenzyl) ammonium hydroxide inner salt.
     (2) Color additive mixtures for use in externally applied drugs made
 with D&C Blue No. 4 may contain only those diluents that are suitable
 and that are listed in part 73 of this chapter for use in color additive
 mixtures for coloring externally applied drugs.
     (b) Specifications. D&C Blue No. 4 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 good manufacturing
 practice:
 
 Sum of volatile matter (at 135 deg.C) and chlorides and sulfates
 (calculated as sodium salts), not more than 15 percent.
 Water-insoluble matter, not more than 0.2 percent.
 Leuco base, not more than 5 percent.
 Sum of o-, m, and p- sulfobenzaldehydes, ammonium salt, not more than
 1.5 percent.
 N-ethyl, N-(m- sulfobenzyl) sulfanilic acid ammonium salt, not more than
 0.3 percent.
 Subsidiary colors, not more than 6 percent.
 Chromium (as Cr), not more than 50 parts per million.
 Lead (as Pb), not more than 20 parts per million.
 Arsenic (as As), not more than 3 parts per million.
 Mercury (as Hg), not more than 1 part per million.
 Total color, not less than 85 percent.
 
 [[Page 399]]
 
     (c) Uses and restrictions. D&C Blue No. 4 may be safely used in
 externally applied drugs in amounts consistent with good manufacturing
 practice.
     (d) Labeling. The label of the color additive and any mixtures
 prepared therefrom intended solely or in part for coloring purposes
 shall conform to the requirements of Sec. 70.25 of this chapter.
     (e) Certification. All batches of D&C Blue No. 4 shall be certified
 in accordance with regulations in part 80 of this chapter.