Tincture  oj  Strophanthus . 
(  Am.  Jour.  Pharm. 
I   November,  1920. 
STANDARDIZATION  OF  TINCTURE  OF  STROPHANTHUS.* 
By  C.  T.  Bennett,  B.Sc,  F.I.C.,  F.C.S.,  Pharmaceutical  Chemist. 
Without  attempting  to  carry  out  the  elaborate  researches  sug- 
gested in  the  Conference  Research  List,  I  venture  to  put  forward 
a  few  suggestions  for  the  consideration  of  a  future  Pharmacopoeia 
Revision  Committee. 
The  variation  in  strength  of  tincture  of  strophanthus  was  the 
subject  of  a  note  by  my  late  chief,  Mr.  J.  C.  Umney,  published  in 
The  British  and  Colonial  Pharmacist  of  December,  1918,  p.  375.  In 
this  note  it  was  pointed  out  that  the  standards  adopted  for  physio- 
logically testing  this  potent  drug  differed  considerably,  the  mini- 
mum lethal  dose  calculated  for  a  100  Gm.  frog  being  as  follows  for 
various  commercial  samples: 
M.L.D.  for  100  Gm.  Frog. 
U.  S.  P.  standard  ( I  hour)   0.006  Cc. 
Standard  adopted  by  the  Society  of 
Apothecaries   0.020  (since  altered  to  o.oi  Cc.) 
Sample  "A"  (time  not  stated)   o .  007  Cc. 
Sample  "B"  (time  not  stated)   0.020  Cc. 
Sample  "C"  (time  not  stated)   0.050  Cc. 
Sample  "D"  (2  hours)   o.  150  Cc. 
Sample  "E"  (2  hours)   0.150  Cc. 
If  the  standards  adopted  vary  to  such  an  enormous  extent  as 
shown  by  these  figures,  then  it  is  obvious  that  physiological  stand- 
ardization will  fall  into  disfavor  unless  an  international  standard 
be  agreed  upon. 
According  to  Rowe  {Y.  B.  P.,  1917,  p.  264),  commercial  samples 
of  strophanthus  tested  physiologically  have  shown  enormous  vari- 
ation in  potency,  but  since  19 13  samples  examined  by  him  have  been 
much  more  uniform.  He  takes  exception,  however,  to  the  use  of 
ouabain  or  gratus-strophanthin  as  a  standard,  and^  considers  that 
crystalline  Kombe  strophanthin  is  the  proper  standard. 
The  strength  of  the  tincture  official  in  the  British  Pharmacopoeia, 
19 1 4,  is  four  times  that  of  the  1898  tincture,  viz.,  i  in  10  by  volume 
(100  Gms.  of  the  seeds  in  1000  Cc.  of  tincture)  in  accordance  with 
the  International  Agreement  of  1906,  and  identical  in  strength  with 
that  of  the  United  States  Pharmacopoeia,  except  that  the  latter  is 
prepared  with  95  per  cent,  alcohol. 
*  Reprinted  from  The  Pharmaceutical  Journal  and  Pharmacist,  July  24,  1920. 
