[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: 21CFR73.1299]
 
 [Page 367-368]
 
                         TITLE 21--FOOD AND DRUGS
 
 CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                                 SERVICES
 
 PART 73--LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION--Table of Contents
 
                             Subpart B--Drugs
 
 Sec. 73.1299  Ferric ferrocyanide.
 
     (a) Identity. (1) The color additive ferric ferrocyanide is a ferric
 hexacyanoferrate pigment characterized by the structual formula
Fe<INF>4</INF>¬Fe(CN)<INF>6</INF>|<INF>3</INF><t-bullet>XH<INF>2</INF>O,
 which may contain small amounts of ferric sodium ferrocyanide and ferric
 potassium ferrocyanide.
 
 [[Page 368]]
 
     (2) Color additive mixtures for drug use made with ferric
 ferrocyanide may contain only those diluents listed in this subpart as
 safe and suitable for use in color additive mixtures for coloring drugs.
     (b) Specifications. Ferric ferrocyanide 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:
 
 Water soluble cyanide, not more than 10 parts per million.
 Lead (as Pb), not more than 20 parts per million.
 Arsenic (as As), not more than 3 parts per million.
 Nickel (as Ni), not more than 200 parts per million.
 Cobalt (as Co), not more than 200 parts per million.
 Mercury (as Hg), not more than 1 part per million.
 Oxalic acid, not more than 0.1 percent.
 Water soluble matter, not more than 3 percent.
 Volatile matter, not more than 10 percent.
 Total iron (as Fe corrected for volatile matter), not less than 37
 percent and not more than 45 percent.
 
     (c) Uses and restrictions. Ferric ferrocyanide may be safely used in
 amounts consistent with good manufacturing practice to color externally
 applied drugs including those intended for use in the area of the eye.
     (d) Labeling requirements. The label of the color additive and of
 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) Exemption from certification. Certification of this color
 additive is not necessary for the protection of the public health, and
 therefore batches thereof are exempt from certification requirements of
 section 721(c) of the act.
 
 [43 FR 54235, Nov. 21, 1978]