Am.  Jour.  Phariu. 
October,  1903. 
Granular  Effervescent  Salts. 
465 
proper  temperature,  and  the  whole  mass  manipulated  until  it  be- 
comes  uniformly  moistened  ;  it  is  then  passed  through  a  suitable 
sieve  and  finally  dried  in  hot-air  closets. 
When  the  retail  pharmacist,  however,  attempts  to  make  a  granu- 
lar effervescent  salt  by  the  same  method,  but  with  the  apparatus 
usually  at  hand,  he  meets  with  the  difficulty  of  securing  a  properly 
regulated  heat,  and  the  salt  does  not  become  uniformly  moist ;  the 
surfaces  which  are  exposed  to  the  air  become  dry  before  the  remain- 
ing portion  is  moistened,  and  the  resulting  granular  salt  is  often  not 
satisfactory. 
While  the  expert  may  obtain  a  nicely  granulated  preparation  by 
the  use  of  a  dish  and  open  fire,  yet  the  experience  with  classes  in 
the  college  laboratory  has  shown  that  it  is  rather  the  exception 
that  uniformly  good  results  can  be  obtained  by  this  method,  while 
the  modified  manipulation,  suggested  in  this  paper,  yields  good 
results,  even  in  the  hands  of  a  novice,  and  is  adapted  to  the  use  of 
a  retail  pharmacist. 
Numerous  experiments  have  shown  that  a  mixture  of  sodium 
bicarbonate,  tartaric  acid  and  citric  acid,  in  a  proportion  which  will 
•produce  a  solution  of  neutral  sodium  tartrate  and  sodium  citrate, 
and  so  adjusted  that  just  sufficient  moisture  will  be  present  to  pro- 
duce a  pasty  mass,  without  marked  effervescence  when  the  whole  is 
heated,  may  be  taken  as  the  basis  of  many  medicated  granular  effer- 
vescent salts,  and  good  results  obtained,  even  when  the  proportion 
of  medicating  substance  varies  considerably,  the  precaution  always 
being  observed,  however,  to  thoroughly  dry  every  addition.  The 
following  mixture  fulfils  these  conditions : 
Powder  the  citric  acid  and  add  the  tartaric  acid  and  sodium 
bicarbonate. 
This  basis  may  be  mixed  with  many  of  the  medicaments  com- 
monly used  in  the  form  of  granular  effervescent  salts,  in  the  propor- 
tion which  will  properly  represent  their  doses,  and  such  substances 
as  sodium  phosphate,  magnesium  sulphate,  citrated  caffeine,  potas- 
sium bromide,  lithium  citrate,  potassium  citrate,  and  others,  will 
produce  satisfactory  products.  A  typical  formula  would  be  as 
follows : 
BASIS  FOR  EFFERVESCENT  SAI/TS. 
Sodium  bicarbonate,  dried  and  powdered 
Tartaric  acid,  dried  and  powdered  .  .  . 
Citric  acid,  uneffloresced  crystals  .  .  .  . 
530  grammes. 
280  " 
180 
