Am.  Jouk.  Phaem.  1 
Feb.  1,  1874.  / 
Ammonio-  Citrate  of  Iron. 
7S 
AMMONIO-CITRATE  OF  IRON. 
By  Charles  Umney. 
The  variation  in  appearance  of  animonio- citrate  of  iron,  as  met 
with  in  trade,  must  have  been  noticed  by  every  observant  pharmacist. 
Since  the  time  of  its  introduction  into  medicine  by  Beral,  now  about 
thirty  years  since,  most  manufacturers  have  adopted,  notwithstanding 
the  various  officinal  formulae  that  have  been  published,  one  or  other 
of  the  following  nethods  for  its  production 
(a)  .  By  dissolving  metallic  iron  (nails)  in  a  solution  of  citric  acid 
by  the  aid  of  heat  to  the  complete  saturation  of  the  acid. 
(b)  .  By  adding  hydrated  ferric  oxide  to  citric  acid  dissolved  in  about 
twice  its  weight  of  water,  assisting  its  solution  by  the  heat  of  a  water- 
bath  until  the  oxide  is  no  longer  dissolved,  and  is  visibly  in  excess. 
Solution  of  ammonia  in  both  cases  being  added  after  filtration,  to 
produce  the  double  salt.  By  either  method  the  result  is  very  similar, 
the  amount  of  anhydrous  ferric  oxide  resulting  from  a  calcination  of 
the  salt  with  free  exposure  to  air  from  30  to  31  per  cent.,  and  the  ap- 
pearance of  the  scaled  product  nearly  or  quite  identical. 
A  review  of  the  various  formulas  that  have  been  published  in  the 
London  and  British  Pharmacopoeias  will  serve  not  only  to  show  the 
relative  amounts  of  ferric  oxide  directed  to  be  added  to  the  citric  acid, 
but  also  to  indicate  (when  the  examination  of  commercial  specimens 
is  brought  forward)  that  obsolete  processes  are  followed  by  manufac- 
turers. 
As  this  iron  salt  is  almost  universally  used,  it  will  be  interesting 
at  the  same  time  to  note  the  formulae  of  the  French  Codex  and  the 
United  States  and  German  Pharmacopoeias. 
London  Pharmacopoeia,  1851.  (First  Officinal.) 
Sulphate  of  Iron,         .  .  .  .  12  oz.  Troy. 
Carbonate  of  Soda,  ....    12 J  oz. 
Citric  Acid,      .  .  .  .  .  6  oz. 
Solution  Ammonia,  ^-960)     .  .  .  .    9  fl.  oz. 
British  Pharmacopeia,  1864. 
Solution  of  Persulphate  of  Iron  (1441)  .  8  fl.  oz. 
Citric  Acid,         .  .  .  .  5  oz.  (Avoir.) 
Sol.  Ammonia,  (.960)  .  .  .  14  fl.  oz. 
