6oo 
Agar-Agar  Suppositories. 
j  Am.  Jour.  Pharm. 
i.  December.  1895. 
qualities  of  the  suppositories  made  with  agar-agar  and  with  sodium 
stearate,  which  is  so  largely  used  in  this  country,  the  writer  decided 
to  investigate  the  matter. 
Agar-agar  is  a  substance  obtained  from  several  species  of  algae. 
It  is  known,  also,  as  Japanese  isinglass.  (See  United  States  Dis- 
pensatory, seventeenth  edition,  pages  724  and  1638). 
The  formula  published  was  as  follows  : 
Agar-agar   10  grammes. 
Distilled  water  200  cubic  centimeters. 
Glycerin  200  grammes. 
Dissolve  the  agar-agar  in  the  water  by  the  aid  of  heat,  constantly 
stirring,  add  the  glycerin,  and  strain  while  hot. 
Following  these  directions,  the  writer  prepared  a  sample  of  sup- 
positories from  the  given  quantities.  The  suppositories,  therefore, 
contained  50  per  cent,  of  glycerin.  They  were  very  elastic,  and 
had  not  sufficient  firmness  to  admit  of  being  easily  introduced  into 
the  rectum.  Such  an  article  would  hardly  be  received  with  much 
favor  by  the  physicians  of  this  country.  A  sample  of  suppositories 
containing  75  per  cent,  of  glycerin  was  then  made.  These  were 
firmer  than  those  containing  50  per  cent.,  and  could  be  used 
without  much  difficulty ;  however,  they  did  not  possess  the  firm- 
ness of  those  made  with  sodium  stearate. 
An  attempt  was  made  to  produce  suppositories  stronger  than 
75  per  cent.,  but  it  was  without  good  results,  as  the  glycerin  had  a 
tendency  to  separate  from  the  mass  upon  cooling. 
In  making  the  suppository  mass  it  was  found  better  to  change 
the  manipulation  somewhat.  The  agar-agar  was  first  soaked  with 
cold  water,  and  the  latter  expressed.  After  calculating  the  amount 
of  water  retained,  sufficient  to  supply  the  proper  amount  was  added. 
The  glycerin  was  then  added,  and  the  whole  heated  on  a  water-bath 
until  the  agar-agar  was  dissolved,  after  which  the  solution  was 
strained. 
The  following  formula  may  be  used  by  these  directions  for  a  sup- 
pository mass  containing  75  per  cent,  of  glycerin. 
Agar-agar   5  grammes. 
Distilled  water  45  cubic  centimeters. 
Glycerin  150  grammes. 
On  account  of  the  smaller  quantity  of  glycerin  contained  and  the 
elasticity  of  the  mass,  I  do  not  consider  the  product  of  this  method 
