AnMJa0rch,?89Lm-}     Granular  Effervescent  Pozvders.  135 
A  glance  at  the  formula  (H3C6H507'H20)  will  show  that  water  is 
present.  This  is  given  off  in  heating,  and  the  moisture  thus 
obtained  partially  forms  a  syrup  with  the  sugar,  which  acts  as  an 
adhesive  agent  during  the  melting  process.  The  object  aimed  at  is 
to  apply  only  sufficient  heat  to  cause  adhesion  and  at  the  same  time 
to  lose  as  little  C02  as  possible  during  the  process.  Care  must  also 
be  taken  not  to  raise  the  temperature  too  high,  as  the  preparation 
would  then  be  rendered  much  less  freely  soluble.  Before  looking 
on  the  different  methods  of  granulation  I  would  say  that  efferves 
cent  preparations  in  this  form  are  gaining  popularity  year  by  year. 
In  a  pleasant  draught  an  unpalatable  drug  may  be  taken,  its 
nauseousness  being  corrected  by  that  pleasant,  sharp  taste  due  to 
the  presence  and  escape  of  carbonic  acid  gas.  The  popularity  of 
such  preparations  as  gran,  effervescent  antipyrin,  citrate  of  caffeine, 
lithia,  sulphate  of  soda,  etc.,  is  in  itself  sufficient  proof  that  they  are 
preferred  to  the  ancient  manner  of  a  pill,  powder  or  bitter  draught. 
Again,  when  taking  a  dose  of  caffeine,  for  example,  the  effervescing 
draught  in  itself  acts,  and  independent  of  the  presence  of  the  active 
ingredient,  produces  a  soothing  and  good  effect  upon  the  patient. 
Three  methods  of  granulation  have  been  advocated.  (1)  To 
make  the  mass  into  a  tough  paste  with  S.V.R.,  press  the  mass 
through  a  large  meshed  sieve  and  dry  quickly.  (2)  To  heat  the 
dried  ingredients  together  until  a  temperature  between  2000  and 
2200  F.  is  reached,  stirring  well  all  the  while  to  form  granules ; 
then  by  means  of  suitable  sieves  separating  the  granules  and  pre- 
serving in  well-closed  bottles.  The  foregoing,  as  will  be  perceived, 
is  the  pharmacopceial  method  To  both  of  these  processes  expe- 
rience shows  there  are  objections.  The  objections  to  the  first  may 
be  readily  seen,  inasmuch  as  it  is  an  expensive  and  comparatively 
poor  method.  In  the  official  process  I  have  found  a  large  amount 
of  waste,  as  it  is  impossible  to  get  all  the  base  and  active  ingredients 
into  granular  form,  the  large  proportion  of  powdery  product  mixed 
with  the  granules  giving  the  preparation  an  inelegant  and  "  saline  " 
appearance.  To  follow  the  directions  of  the  B.P.,  the  granules  of 
perfect  form  are  to  be  separated  from  the  powdery  product.  But  is 
it  not  possible  that  the  active  ingredient — or  a  large  percentage  of 
it — may  be  contained  in  this  part  of  the  preparation  ? 
The  process,  I  venture  to  say,  which  beats  the  two  foregoing,  is 
that  of  heating  quickly,  with  manipulation,  the  ingredients  till  the 
