468 
Syrup  Ferroi^s  Iodide. 
f  Am.  Jour.  Pharm. 
I     October,  1900. 
SYRUP  FERROUS  IODIDE.1 
By  H.  Lionei,  Meredith. 
This  paper  is  to  be  regarded  as  an  answer  to  the  query: 
"  Glucose  and  glycerin  have  both  been  recommended  as  preserva- 
tives for  syrup  ferrous  iodide.  Does  the  presence  of  either  or  both 
these  substances  really  improve  the  keeping  quality  of  this  syrup 
beyond  that  of  the  U.S.P.  article  ?  If  so,  suggest  a  formula."  We 
find  that  as  early  as  1857  Mr.  Frederick  Stearns  suggested  the  use 
of  glycerin  as  an  entire  substitute  for  syrup  in  preparing  this  prepa- 
ration, thus  making  a  sort  of  glycerite  instead  of  a  syrup ;  and  in 
the  following  year  Dr.  Henry  Thayer  advocated  partial  replacement 
of  the  syrup  by  this  same  body,  thus  preserving  the  title  of  the 
preparation,  and  obtaining  the  same  effect  only  to  a  proportionate 
degree. 
Medicinally,  glycerin  is  not  objectionable;  indeed,  in  instances  it  is 
to  be  preferred  to  syrup.  In  the  first  place,  because  sugars  of  the 
disaccharide  class  of  carbohydrates  are  contraindicated  in  many 
diseases ;  then,  too,  this  class  of  sugars  are  not  digestible  until  con- 
verted by  the  stomachic  secretions  into  a  type  of  invert  sugar,  which 
change  frequently  progresses  to  an  advanced  stage  and  produces 
what  is  known  as  "  acidity  of  the  stomach,"  or  "  fermentative  indi- 
gestion."   Glycerin  is  open  to  no  such  criticism. 
The  effect  of  iodine  upon  sugar  was  noticed  by  Lassaigne  as  early 
as  1833;  tnat  by  prolonged  boiling  of  iodine  with  a  solution  of  cane 
sugar  he  obtained  a  colorless  solution;  and  Millon,  in  1845,  asserted 
that  iodoform  was  formed  by  him  by  elevating  the  temperature  of 
a  glucose  solution  to  which  iodine  had  been  added,  the  reaction  tak- 
ing place  in  the  presence  of  an  alkaline  carbonate. 
Prof.  John  M.  Maisch,  in  1857,  noted  that  direct  sunlight  would 
restore  the  proper  color  conditions  of  a  discolored  syrup  of  ferrous 
iodide,  while  the  sunheat,  without  sunlight,  would  not  accomplish 
the  same  end.  The  results  of  these  early  investigators  seem  to  indi- 
cate that  preservation  and  decolorization  are  brought  about  by  a 
process  of  reduction ;  that  as  fast  as  the  syrup  had  been  oxidized  and 
iodine  liberated,  it  in  turn  was  reduced  and  hydriodic  acid  formed  as 
a  product  of  that  reduction. 
Abstract  of  a  paper  read  at  the  Maryland  Pharmaceutical  Association,  June, 
1900. 
