ii4 
Standardization  of  Preparations. 
Am.  Jour.  Pharm. 
March,  1908. 
determined  for  a  warm-blooded  animal  as  a  control  over  the  chemi- 
cal assay  rather  than  the  commonly  accepted  method  of  standardiz- 
ing digitalis  by  means  of  its  action  on  the  frog's  heart. 
The  idea  is  rapidly  gaining  ground  among  clinicians  that  digi- 
toxin  is  the  real  active  principle  of  digitalis,  from  which  all  the 
effects  of  digitalis  preparations  can  be  obtained.  Its  use  in  a  pure 
condition  probably  is  a  long  way  off,  as  no  satisfactory  preparations 
have  yet  been  made  available,  and  we  must  still  depend  for  the  most 
part  on  a  reliable  tincture  or  fluidextract  for  digitalis  therapy ;  but 
as  there  are  several  other  principles  in  digitalis  other  than  digitoxin, 
which  are  not  inert,  but  evidently  reinforce  digitoxin  in  its  action, 
and  as  these  principles  are  not  easily  determined  by  chemical  assay, 
it  seems  advisable  that  digitalis  should  be  standardized,  as  to  digi- 
toxin content,  which  assures  us  of  its  therapeutic  effect  and,  further, 
more,  the  toxic  action  of  the  combined  principles  should  be  deter- 
mined by  means  of  physiological  test. 
2.    BY  CHEMICAL  MEANS. 
By  Charges  B.  Vanderkeeed. 
Both  the  title  of  the  fourth  paper  on  our  programme  this  evening 
and  the  time  at  our  disposal  limit  the  scope  of  this  contribution  to 
a  discussion  of  the  standardization  of  digitalis  preparations,  and, 
therefore,  to  review  the  chemical  work  on  this  interesting  drug,  of 
such  men  as  Homolle,  Nativelle,  Schmiedeberg  and  Keller,  the 
monumental  researches  of  Kiliani,  or  the  more  recent  discus- 
sion of  the  latter  with  Cloetta  in  regard  to  his  (Cloetta's)  so-called 
amorphous  digitoxin  is  uncalled  for.  Moreover,  it  is  not  yet  possible 
to  settle  beyond  all  doubt  the  accuracy  of  the  various  chemical  views 
about  the  digitalis  glucosides  that  have  been  supported  by  the  vari- 
ous investigators,  although  it  is  generally  conceded  that  Kiliani's 
work  affords  us  the  most  exhaustive  and  reliable  data  concerning 
this  very  interesting  and,  in  part,  very  valuable  substance.  It  may 
not  be  out  of  place,  therefore,  to  endeavor  to  sum  up  briefly  such 
facts  as  all  are  agreed  upon  in  order  to  have  before  us  a  clear  view 
of  the  digitalis  standardization  problem. 
All  authorities  agree  that  digitalis  leaves  vary  greatly  in  physio- 
logical activity,  that  those  of  the  first  year's  growth  are  practically 
inactive,  and  that  those  only  of  the  second  year's  growth,  collected 
preferably  at  the  commencement  of  flowering,  should  be  employed. 
