340 
The  Stability  of  Iodine  Ointments.     {Am  jour.  Pharm. 
J      3  K        Aug.  19 1 7. 
showed  that  it  contained  but  about  0.43  per  cent,  of  iodine,  all  of 
which  was  in  a  free  state.  The  fact  that  all  of  the  iodine  present 
was  in  the  free  state  appeared  to  indicate  that  iodine  is  relatively 
stable  in  liquid  petrolatum  solutions. 
Iocamfen  is  a  liquid  composed  of  iodine,  camphor  and  phenol. 
It  was  claimed  to  contain  10  per  cent,  of  free  iodine.  Analysis 
showed  that  it  contained  9.3  per  cent,  of  total  iodine  (of  which  7.5 
per  cent,  was  present  in  an  uncombined  state),  66.1  per  cent,  of 
camphor  and  19.7  per  cent,  of  phenol.  After  storing  for  several 
months  a  second  assay  of  Iocamfen  showed  no  appreciable  loss  in 
iodine  content.  This  would  indicate  that  iodine  is  relatively  stable 
in  presence  of  phenol  and  camphor,  although  immediately  after  mix- 
ing there  is  some  loss  of  free  iodine.  The  Iocamfen  Ointment  was 
supposed  to  contain  50  per  cent,  of  Iocamfen  (equivalent  to  5  per 
cent,  of  free  iodine)  in  a  lard-wax-cacao-butter  base.  The  analysis 
showed  that  the  ointment  contained  but  0.4  per  cent,  of  free  iodine, 
the  balance  being  in  combination.  From  the  results  of  the  ex- 
amination, and  from  corespondence  with  the  manufacturers  (Scher- 
ing  and  Glatz),  it  became  evident  that  the  only  plausible  explanation 
for  the  loss  of  free  iodine  in  the  preparation  of  Iocamfen  Ointment 
from  Iocamfen  lay  in  the  combination  of  the  free  iodine  with  the 
ingredients  of  the  ointment  base.  It  seems  likely  that  the  free  iodine 
originally  present  in  Iocamfen  for  the  most  part  had  gradually  gone 
into  combination  with  the  fatty  substances  after  the  ointment  had 
been  prepared. 
The  literature  was  then  examined  to  determine  the  consensus  of 
opinion  concerning  the  stability  of  iodine  in  iodine  ointment.  In  the 
older  literature  the  belief  that  iodine  ointment  is  unstable  appears 
to  be  quite  general.    Such  statements  as  the  following  are  typical :  . 
The  ointment  should  be  prepared  only  when  wanted  for  use,  for  it  under- 
goes change  if  kept,  losing  its  deep,  orange-brown  color,  and  becoming  pale 
upon  it's  surface.4 
It  is  better  to  prepare  it  only  as  it  is  required  for  use.5 
This  ointment  must  not  be  dispensed  unless  it  has  recently  been  pre- 
pared.6 
In  1909  Lythgoe,7  of  the  Massachusetts  Board  of  Health  lab- 
oratory, reported  an  examination  of  four  samples  of  iodine  ointment. 
4U.  S.  Disp.,  ed.  19,  p.  1315. 
5  Am.  Disp.,  ed.  2,  p.  2022. 
6  U.  S.  Pharmacopeia,  IX,  p.  481. 
7  Rep.  Mass.  Bd.  Health,  41,  477  (1909). 
