464 
Granular  Effervescent  Salts. 
(  A.m.  Jour.  Pharm. 
I     October,  1903. 
GRANULAR  EFFERVESCENT  SALTS.1 
By  E.  Fui^erton  Cook,  P.D. 
The  increase  in  the  use  of  granular  effervescent  salts  has  been  so 
marked  within  recent  years,  and  the  process  of  manufacture  so 
greatly  simplified,  that  every  retail  pharmacist  should  be  independent 
of  the  manufacturer  for  this  class  of  preparations.  The  fact  that  a 
nauseous  dose  of  medicine  may  be  taken  with  comparative  ease 
when  mixed  with  an  effervescent  drink  or  one  highly  charged  with 
carbon  dioxide,  has  long  been  known,  and  the  introduction  of  effer- 
vescent salts  has  made  it  possible  to  take  advantage  of  this  principle 
without  the  inconvenience  of  obtaining  a  previously  carbonated 
water.  This  fact  was  soon  recognized,  but  for  years  the  price  was 
almost  prohibitory  because  of  the  expensive  method  of  manufacture, 
and  since  it  required  elaborate  apparatus  for  recovering  the  alcohol, 
its  preparation  was  entirely  outside  the  province  of  the  retail  phar- 
macist. 
In  the  former  method  the  powders,  consisting  of  tartaric  acid  and 
sodium  bicarbonate  in  the  proper  proportion,  together  with  the 
medicating  substance,  are  thoroughly  dried  and  powdered,  and  when 
uniformly  mixed,  moistened  with  alcohol  and  forced  through  a  suit- 
able sieve,  to  divide  the  pasty  mass  into  granules ;  they  are  then 
thoroughly  dried. 
As  the  powders  are  only  moistened  with  alcohol,  in  which  they 
are  practically  insoluble,  the  finished  preparation  retained  its  prop- 
erty of  effervescence  when  dissolved  in  water ;  but  the  use  of  alcohol, 
much  of  which  was  lost  in  the  process,  increased  the  cost  and  pre. 
vented  the  preparations  from  gaining  great  popularity. 
Within  a  comparatively  short  time,  however,  this  method  has 
been  entirely  superseded  by  a  much  less  expensive  and  more  simple 
process,  which  takes  advantage  of  the  one  molecule  of  water  of 
crystallization  in  citric  acid  for  supplying  the  desired  moisture. 
Enough  of  the  tartaric  acid  is  replaced  by  citric  acid  to  make  a 
pasty  mass  of  the  powders  when  they  are  subjected  to  a  temperature 
which  will  liberate  the  water  of  crystallization.  In  the  large  labora- 
tory, when  a  suitable  formula  has  been  selected,  the  mixed  powders 
are  placed  in  a  steam-jacketed,  porcelain-lined  kettle,  kept  at  the 
1  Read  at  the  annual  meeting  of  the  Pennsylvania  Pharmaceutical  Associa- 
tion, June,  1903,  and  contributed  by  the  author. 
