Am.  Jour.  Pharru.  ) 
April,  1913.  j 
Tincture  of  Iodine. 
153 
at  a  good  price  for  all  that  the  grower  can  grow,  but  he  must  labor 
well  and  long,  and  in  patience  must  he  wait  for  it. 
Twinsburg,  Ohio,  February,  191 3. 
TINCTURE  OF  IODINE* 
By  L.  F.  Kebler, 
Chief  Drug  Division,  Bureau  of  Chemistry,  U.  S.  Department  of  Agriculture. 
This  commodity  has  probably  been  examined  more  frequently 
than  any  other  simple  drug  offered  for  sale  by  the  retail  trade  and 
I  know  of  no  medicinal  agent  which  has  more  frequently  been  found 
wanting.  Observations  and  investigations  have  frequently  shown 
that  when  iodine  was  dissolved  in  simple  ethyl  alcohol  there  was  a 
great  tendency  for  the  iodine  to  be  changed  into  hydriodic  acid  and 
other  compounds  thus  actually  lowering  the  free  iodine  content  and 
the  diminution  increased  'with  the  age  of  the  preparation.  Experi- 
ments conducted  to  obviate  this  difficulty  indicated  that  the  presence 
of  potassium  iodide  tended  to  inhibit  the  usual  combination  of  the 
iodine  and  thus  increase  the  stability  of  the  tincture.  The  method 
outlined  for  the  manufacture  of  this  commodity  by  the  last  (8th) 
revision  of  the  U.  S.  Pharmacopoeia  prescribes  the  use  of  a  certain 
amount  of  potassium  iodide.  The  shortcomings  of  the  tinctures 
available  on  the  market  have,  however,  not  been  materially  reduced. 
Almost  every  State  Board  which  has  taken  up  this  question  has 
found  that  a  large  number  of  the  samples  are  deficient  in  iodine 
content.  This  shortcoming  cannot  now  be  so  fully  ascribed  to 
deterioration,  neither  can  it  be  ascribed  to  difficulties  in  manufacture 
because  the  process  of  manufacture  is  extremely  simple. 
During  the  past  few  years  a  considerable  number  of  samples  of 
tincture  of  iodine  have  been  examined  in  the  Bureau  of  Chemistry. 
The  samples  shipped  into  interstate  commerce  were  found  to  comply 
closely  with  the  Pharmacopceial  requirements.  All  of  them  contain 
the  requisite  amount  of  potassium  iodide.  A  goodly  number  of 
samples  were  collected  in  the  District  of  Columbia  and  analyzed 
with  the  following  results : 
*  Read  before  the  City  of  Washington  Branch  American  Pharmaceutical 
Association,  February  12,  1913,  and  contributed  by  the  author. 
