Am.  Jour.  Pharni .  \ 
February,  1909.  j 
The  Assay  of  Drugs. 
6S 
the  assay  of  opium,  or  modifications  adapted  to  particular  drugs, 
such  as  cinchona  and  nux  vomica.  The  assay  methods  for  galenical 
preparations  are  likely  to  be  applied  by  retail  pharmacists  more  than 
those  for  crude  drugs,  since  the  employment  of  a  standard  drug  does 
not  assure  a  standard  product.  Their  interest  as  well  as  that  of  the 
public  is  subserved  by  their  exercising  due  control  over  such  prod- 
ucts, for  which,  moreover,  they  cannot  usually  transfer  the  re- 
sponsibility. The  methods  are  generally  quite  similar  to  those  for 
crude  drugs,  but  more  expeditious,  since  the  active  principle  is 
usually  already  in  solution  or  readily  dissolved. 
Assaying  the  finished  product  does  not  secure  a  complete  remedy 
for  all  the  abnormalities  in  drugs  which  may  be  occasioned  by  natural 
variation,  accidental  deterioration,  or  the  ignorance,  carelessness  or 
cupidity  of  those  through  whose  hands  they  pass.  An  assay  will 
show,  for  example,  how  much  alkaloid  is  present  in  a  certain  prepara- 
tion, provided  it  is  the  characteristic  alkaloid  of  the  drug  in  question. 
Ordinarily  it  will  not  show  whether  it  is  that  particular  alkaloid  or  a 
mixture  of  alkaloids ;  nor  will  it  usually  indicate  whether  the  original 
drug  was  mixed  with  other  drugs  or  inert  matter,  or  properly  cured 
and  in  a  good  state  of  preservation.  The  physical  examination  of 
the  original  crude  drug  is  a  very  important  factor  in  controlling  the 
quality  of  drug  products.  The  process  of  grinding  destroys  many 
of  the  characteristics,  and  it  is  difficult  to  determine  the  quality  of 
finely  ground  drugs  even  with  the  microscope.  The  efficient  im 
spection  and  control  of  crude  drugs  at  the  point  of  importation  into 
the  country  is  therefore  a  very  valuable  agency  in  preventing  the 
distribution  of  objectionable  drugs. 
