Am.  Jour.  Pharm. 
Dec,  1878. 
}  Sodium  Salicylate.  569 
NOTE  ON  SODIUM  SALICYLATE. 
By  Charles  W.  Drew,  Ph.B. 
The  very  extensive  and  increasing  application  of  sodium  salicylate 
in  medical  practice  renders  it  desirable  that  some  method  which  can 
be  relied  upon  to  produce  a  pure  and  uniform  product,  and  which  at 
the  same  time  affords  the  greatest  attainable  simplicity  of  manipulation, 
should  be  generally  known  among  pharmacists.  With  a  view  toward 
supplying  this  need,  I  would  call  attention  to  the  results  here  embodied, 
which  are  derived  from  personal  observation  and  experience  in  the 
manufacture  of  the  salt. 
Salicylic  acid,  C7H603,  is  a  bibasic  acid,  though  the  neutral  salts  of 
the  monad  metals  have  not  as  yet  been  prepared.  The  chief  medici- 
nal salt  of  salicylic  acid  is  the  acid  sodium  salicylate,  NaC7H5G3.  This 
salt  may  be,  and  has  been,  prepared  in  several  ways,  most  of  which 
have  been  more  or  less  unsatisfactory,  either  from  the  impurity  or  vari- 
ability of  the  product,  or  from  the  complicated  nature  of  the  process 
itself. 
The  simplest  methods  for  the  preparation  of  the  salt  are  by  the 
treatment  of  salicylic  acid  with  either  the  sodium  monocarbonate  or 
sodium  dicarbonate.  If  the  normal  carbonate  is  employed  the  reac- 
tion which  takes  place  is  in  accordance  with  the  formula  :  2(C7H603) 
-f-Na2C03.ioaq.=2(NaC7H603)+CO.,+  H20-f-ioaq. 
From  this  reaction  we  deduce  the  fact  that  1  part  of  salicylic  acid, 
treated  with  1*036  part  of  crystallized  sodium  monocarbonate,  yields 
1*15  parts  of  sodium  salicylate. 
If  the  acid  sodium  carbonate  is  employed,  the  reaction  is  expressed 
by  the  formula  :  C7H6Os+NaHCOs=NaC7H603+C02+H20. 
This  similarly  admits  the  deduction  that  1  part  of  salicyic  acid 
treated  with  *6o8  part  of  acid  sodium  carbonate  pields  1*17  parts  of 
sodium  salicylate. 
For  extemporaneous  dispensing  of  sodium  salicylate  in  solution,  the 
following  formula  will  be  found  available  : 
R        Salicylic  acid,  .  .  .  1230  grs. 
Sodium  dicarbonate,         .  .  .         745  " 
Water  q.s.  for  6  fl.  3. 
Each  minim  of  the  resulting  solution  contains  '5  grain  of  sodium 
salicylate. 
The  best  method  of  making  sodium  salicylate  for  general  dispensing 
