58o 
Relative  Activity  of  Digitalis. 
f  Am.  Jour.  Pharm. 
August,  19 18. 
THE  RELATIVE  ACTIVITY  OF  SEPARATED  PORTIONS 
OF  DIGITALIS. 
By  E.  L.  Newcomb  and  C.  H.  Rogers. 
In  a  previous  paper  a  method  was  presented  for  the  special 
cleaning  of  the  drug  digitalis.  The  digitalis  used  for  the  develop- 
ment of  the  special  cleaning  process  was  prepared  from  plants  of 
Digitalis  purpurea,  first  year's  growth,  grown  in  the  Medicinal  Plant 
Gardens  of  the  College  of  Pharmacy  of  the  University  of  Minnesota. 
The  drug  met  all  U.  S.  P.  IX  requirements  without  the  application  of 
the  special  cleaning  process.  However,  in  view  of  the  lack  of  in- 
formation concerning  the  nature  of  foreign  matter  which  the  U.  S.  P. 
permits  to  be  present  it  was  deemed  wise  to  carry  the  process  of 
eliminating  this  extraneous  material  just  as  far  as  possible  and 
thereby  produce  a  drug  with  a  minimum  of  what  are  possibly  del- 
eterious substances. 
During  the  special  cleaning  process  the  digitalis  was  separated 
into  four  well-defined  portions,  i.  e.,  (a)  select  clean  drug  represent- 
ing petiole  and  lamina  only,  ash  9.284  per  cent.;  (b)  select  clean 
drug  with  petioles  partly  removed,  ash  8.91  per  cent. ;  and  (c)  petiole 
fragments  with  practically  no  lamina  present,  ash  8.76  per  cent. ; 
and  (d)  number  50  fine  powder  sif tings  consisting  of  the  hairs  of 
digitalis,  inorganic  material  and  very  few  lamina  and  petiole  por- 
tions, ash  56.81  per  cent. 
As  the  work  of  cleaning  progressed  a  number  of  questions  arose 
which  demanded  the  application  of  physiologic  methods  for  their 
solution  and  this  further  study,  with  the  results  obtained,  is  herewith 
presented. 
One  of  the  important  questions  to  be  determined  was  the  relative 
activity  of  the  several  separated  portions.  These  values  were  de- 
termined by  the  application  of  the  following  well-known  methods 
for  the  physiological  assay  of  digitalis :  (a)  Reed  and  Vanderkleed 
guinea-pig  method,  (b)  intravenous  cat  methods.  It  is  not  our  pur- 
pose to  discuss  in  this  paper  the  relative  merits  of  the  methods  em- 
ployed although  the  nature  of  the  work  and  the  results  obtained 
causes  us  to  give  preference  to  the  latter. 
A  five  per  cent,  infusion  of  the  select  cleaned  digitalis  represent- 
ing petiole  and  lamina  was  prepared,  and  upon  assay  by  the  guinea- 
pig  method  gave  the  following  results : 
