[Code of Federal Regulations]
[Title 21, Volume 4]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR201.304]

[Page 61]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 201--LABELING--Table of Contents
 
  Subpart G--Specific Labeling Requirements for Specific Drug Products
 
Sec. 201.304  Tannic acid and barium enema preparations.

    (a) It has become a widespread practice for tannic acid to be added 
to barium enemas to improve X-ray pictures. Tannic acid is capable of 
causing diminished liver function and severe liver necrosis when 
absorbed in sufficient amounts. The medical literature reports a number 
of deaths associated with the addition of tannic acid to barium enemas. 
There is a lack of scientific evidence to establish the conditions, if 
any, under which tannic acid is safe and effective for use in enemas. 
Tannic acid for rectal use to enhance X-ray visualization is regarded as 
a new drug within the meaning of section 201(p) of the Federal Food, 
Drug, and Cosmetic Act.
    (b) In view of the hazards involved when tannic acid is used in 
barium enemas, any shipments of tannic acid labeled to come within the 
exemptions under 502(f) of the Act containing such phrases as: 
``Caution: For manufacturing, processing, or repackaging,'' ``For 
prescription compounding,'' or ``Diagnostic reagent--For professional 
use only'' will be regarded by the Commissioner of Food and Drugs as 
misbranded within the meaning of section 502(f) of the Federal Food, 
Drug, and Cosmetic Act unless the label and the labeling bear 
conspicuously a warning to the effect: ``Warning-- Not for use in 
enemas.''
    (c) Any tannic acid intended for use by man and found within the 
jurisdiction of the Federal Food, Drug, and Cosmetic Act labeled 
contrary to this section after 60 days from the date of its publication 
in the Federal Register may be made the subject of regulatory 
proceedings.