374 
Alkaloidal  Estimations. 
\  Atn.  Jour.  Pharm. 
I      August,  1905. 
per  cent,  strychnine,  extract  of  opium  20  per  cent,  of  morphine, 
fluid  extract  of  nux  vomica  I  gramme  strychnine  in  100  c.c.  An 
exception  is  tincture  of  opium,  which  "  should  contain  in  IOO  c.c.  not 
less  than  1-2  nor  more  than  1-25  grammes "  of  morphine.  For 
tinctures  no  directions  for  diluting  to  a  definite  standard  are  given, 
they  being  required  to  contain  "  not  less  than  "  a  stated  amount 
of  alkaloid ;  exceptions  to  this  are  tinctures  of  aconite  and  bella- 
donna leaves,  which  are  to  be  adjusted  to  a  definite  standard.  No 
authority  is  given  for  concentrating  preparations  if  they,  on  assay, 
are  found  below  standard,  and,  since  a  minimum  standard  is  pre- 
scribed for  the  crude  drug,  this  condition  need  perhaps  not  arise- 
But  if  coca  leaves  assaying  04  per  cent,  are  on  hand,  what  disposi- 
tion is  to  be  made  of  them  ?  If  mixed  with  an  equal  bulk  of  leaves 
assaying  06  per  cent.,  may  this  mixture  be  considered  to  be 
coca  U.S.P.  ?  Since  with  opium  the  mixing  of  weaker  and  stronger 
drug  in  proper  proportions  is  specifically  directed,  and  since  no  such 
directions  are  given  for  any  other  drug,  does  this  mean  that  this 
procedure  may  be  used  with  opium  only  ? 
As  was  natural,  the  Keller  method  of  assay,  with  few  exceptions, 
was  adopted  for  the  assay  of  crude  drugs.  For  belladonna  leaves, 
belladonna  root,  coca,  hyoscyamus,  scopola  and  stramonium,  the 
writer's  modification  of  the  Keller  method  [Pharm.  Rev.,  1898,  16, 
p.  180),  which  avoids  the  use  of  aliquot  parts,  was  adopted.  For 
aconite  the  method  of  A,  B.  Stevens  [Pharm.  Arch.,  1902,  6,  p.  49; 
Proc.  A.  Ph.  A.,  51,  776),  in  which  the  drug  is  extracted  with  70  per 
cent,  alcohol,  was  adopted.  For  pilocarpus  the  method  of  A.  B.  Lyons 
(Proc.  A.  Ph.  A.,  1903,  51,  p.  254),  in  which  the  drug  is  percolated 
with  chloroform  in  the  presence  of  ammonia  and  where  also  aliquot 
parts  are  avoided,  is  given. 
For  fluid  extracts  quite  a  variety  of  methods  were  adopted.  Fluid 
extract  of  aconite  is,  of  course,  assayed  by  the  Stevens  method. 
Fluid  extracts  of  belladonna  leaves,  hyoscyamus,  scopola  and  stra- 
monium are  to  be  assayed  by  the  method  suggested  by  the  writer 
(Pharm.  Rev.,  1898,  16,  p.  303),  in  which  the  fluid  extract  is  diluted 
with  water,  made  alkaline  with  ammonia  water  and  extracted  with 
chloroform  without  having  previously  expelled  the  alcohol  contained 
in  the  fluid  extract.  When  assaying  fluid  extract  of  coca  the  same 
method  is  used,  except  that  ether  is  substituted  for  chloroform. 
Fluid  extracts  of  ipecac  and  nux  vomica  are  illustrations  where  the 
