Am.  Jour.  Pharm. 
October,  1915. 
Examination  of  Opium  Alkaloids. 
441 
Codeine  Phosphate. 
The  tests  to  which  the  specimens  of  codeine  phosphate  were  sub- 
jected were  essentially  those  which. will  probably  be  described  in  the 
ninth  revision  of  the  U.  S.  Pharmacopoeia.6  In  addition,  phosphate 
was  determined  in  the  solution  from  which  the  codeine  had  been 
removed,  by  precipitation  as  ammonium  magnesium  phosphate,  heat- 
ing and  weighing  as  magnesium  pyrophosphate. 
The  results  obtained  in  the  examination  are  given  below. 
The  specimen  of  codeine  phosphate  was  a  fine,  white  powder 
which  under  the  microscope  was  seen  to  be  considerably  effloresced. 
It  dissolved  in  water,  leaving  not  more  than  traces  of  insoluble  matter. 
The  specimen  was  free  from  chlorides,  sulphates,  meconates,  cryp- 
topine,  thebaine,  and  morphine.  A  purchased  specimen  of  codeine 
phosphate  appeared  to  be  of  as  good  quality  as  the  one  sent  by  Dr. 
Macht.  It  was  not  effloresced  to  such  a  great  extent.  The  findings 
for  the  two  specimens  are  given  in  Table  I. 
Table  1. 
Composition  of  Two  Specimens  of  Commercial  Codeine  Phosphate. 
Merck 
Merck* 
Theory 
2.68 
8.6ia 
8-3ib 
Alkaloid  
74-13 
70.15 
69.06 
Phosphoric  acid  (H3P04)  
23-75 
22.90 
22.63 
Melting-point  of  isolated  alkaloid 
155-3°  (corr.) 
155.7°  (corr.) 
154  to  156° 
*  Purchased  specimen. 
a,  b.  Codeine  phosphate  crystallized  with  two  molecules  of  water  of  hydration  contains 
8.31  per  cent,  of  water  of  hydration;  with  one  and  one-half  molecule,  6.36  per  cent. 
Codeine  phosphate  was  first  studied  by  Anderson,7  who  obtained 
it  containing  one  and  one-half  molecules  of  water  of  hydration.  It 
was  pointed  out  by  Schmidt,8  a  number  of  years  ago,  that  commercial 
codeine  phosphate  was  of  variable  composition.  Depending  upon  the 
method  of  preparation,  it  might  contain  one-half,  one  and  one- 
half,  or  two  molecules  of  water  of  hydration.  Schmidt  states  that 
codeine  phosphate  effloresces  rapidly  at  ordinary  temperature,  losing 
all  but  one-half  molecule  of  its  water  of  hydration.  He  contends 
that  in  the  interest  of  stability  and  uniform  dosage  the  salt  having 
the  latter  composition  should  be  officialized. 
6  Jour.  Am.  Pharm.  Assoc.,  2,  1389  (1913)- 
1  Annal.  Chem.  Pharm.,  77,  352  (1851). 
8Apoth.  Ztg.,  5,  366  (1890). 
