526 
Adrenalin. 
( Arn.  Jour.  Pharm. 
\  November,  1901. 
solution  gets  distinctly  alkaline  and  left  over  for  several  hours.  A 
yellow  brownish  precipitate  will  be  formed  which  is  the  crude 
adrenalin  in  a  basic  form.  The  precipitate  is  now  .filtered,  washed 
with  water  and  dried.  The  impure  adrenalin  usually  precipitates  in 
a  light  yellow  brownish  tomato-shaped  form,  but  not  infrequently 
in  needles.  The  former  is  an  agglomeration  of  needle  crystals 
and  is  more  or  less  contaminated  with  coloring  matters  and  some 
inorganic  substance,  chiefly  phosphates. 
Instead  of  using  ammonia,  sodium  hydrate  may  be  used  as  a  pre- 
cipitant, but  care  must  be  taken  not  to  use  in  excess,  which  redis- 
solves  adrenalin.  In  order  to  counteract  caustic  alkali,  ammonium 
chloride  or  carbonic  acid  may  be  conveniently  used.  In  fact,  the 
various  modifications  and  combinations  of  these  -processes  may  be 
adopted. 
For  the  further  purification  of  the  adrenalin,  the  crude  adrenalin 
is  dissolved  in  acid  and  alcohol  and  ether  is  added  to  a  sufficient 
quantity.  A  brown  colored  precipitate  is  produced  which  chiefly 
consists  of  coloring  matter  and  inorganic  impurities.  The  precipi- 
tate is  separated  both  by  decantation  and  filtration.  The  filtrate  is 
now  treated  by  one  of  the  above-mentioned  processes,  when  white 
crystalline  precipitate  of  adrenalin  will  be  obtained.  It  is  quickly 
filtered,  washed  with  water  and  then  with  alcohol  and  dried.  The 
process  of  purification  may  be  repeated,  if  desired,  two  or  three 
times. 
Properties  and  Deportments : — 
Adrenalin  is  a  light  white,  micro-crystalline  substance,  having,  so 
far,  observed  to  separate  in  five  different  forms  of  crystals  according 
to  the  condition  of  solutions  from  which  they  be  crystallized:  I. 
Prisms;  2.  Fine  needles;  3.  Rhombic  plates;  4.  Boat  or  leaf- 
shaped;  5.  Wartlike. 
Adrenalin  has  a  slightly  bitter  taste  and  leaves  a  numb  feeling  on 
the  tongue  where  it  has  been  applied.  In  dry  form  it  is  perfectly 
stable.  Adrenalin  shows  weak  alkaline  reaction  on  moistened 
litmus  paper.  Phenolphtalein  also  indicates  slight  alkalinity.  It  is 
soluble  with  difficulty  in  cold  water  and  more  readily  in  hot  water. 
From  the  hot  saturated  aqueous  solution  the  crystals  separate  on 
cooling.  The  colorless  aqueous  solution  of  adrenalin  is  prone  to 
oxidation,  absorbing  oxygen  from  air  and  assuming  colors  from 
beautiful  pink  to  red  and  eventually  brown.    It  is  easily  soluble  in 
