^"^jtti^si""^'}  Pharmaoeutioal  Notes.  311 
magnesium  yields  hydrochloric  acid  and  basic  magnesium  sulphate 
(MgO^MgSO^),  the  latter  of  which  may  be  employed  for  the  prepara- 
tion of  magnesia  by  boiling  with  water,  Epsom  salt  remaining  in 
solution.— C/im.  Ztg.,  1882,  No.  13. 
PHARMACEUTICAL  NOTES. 
By  R.  F.  Faitithorne,  Ph.G. 
Manna  as  an  Excipient  for  Pills. — Certain  substances  are  with  dif- 
ficulty made  into  pills  that  will  retain  the  spherical  form.  Amongst 
others  may  be  named  reduced  iron,  subnitrate  and  subcarbonate  of 
bismuth,  oxalate  of  cerium,  calomel,  bicarbonate  of  sodium,  tannin, 
extract  of  logwood,  Dover's  powder,  acetate  of  lead,  sulphate  of  zinc, 
chlorate  of  potassium,  phosphate  of  iron,  ammonio-ferric  alum,  lactate 
of  iron,  citrate  of  iron  and  ammonium,  aloes,  and  sulphite  of  sodium. 
After  these  have  been  made  up  into  pills  with  any  of  the  ordinary 
excipients  of  a  soluble  character,  they  almost  always  flatten  and  often 
unite  together  in  a  mass  that  is  both  unsightly  and  the  cause  of  much 
inconvenience.  This  difficulty  can  be  overcome  by  using  manna  and 
syrup  in  variable  proportions,  according  to  the  substance  operated  on. 
The  quantity  of  manna  required  is  from  25  to  33  per  cent,  of  weight 
of  the  article  to  be  made  into  pills.  Thus,  if  100  grains  of  reduced 
iron  are  to  be  made  into  50  pills,  25  grains  of  manna  will  be  required, 
together  with  sufficient  syrup  to  make  a  mass.  The  quantity  of  the 
syrup  must  be  carefully  adjusted,  so  as  not  to  have  more  than  enough 
to  produce  a  mass  of  the  proper  pilular  consistence.  When  this  pre- 
caution is  taken,  no  difficulty  will  be  experienced  in  making  pills  which 
will  retain  their  proper  form.  Manna  possesses  certain  advantages 
over  other  excipients  that  render  it  of  value  in  the  instances  named ; 
one  is  its  hardness  and  another  its  solubility.  It  is  certainly  prefer- 
able to  powdered  tragacanth  or  rice  flour,  which  are  frequently  used 
to  give  consistence  to  the  pilular  mass.  I  would  suggest  the  use  of 
manna  in  making  Vallet's  mass,  substituting  it  for  both  sugar  and 
honey.  The  mass  would  be  more  easily  handled  and  firmer  than  that 
as  usually  met  with. 
When  manna  is  used  in  making  pills  with  the  substances  named  it 
is  best  to  place  it  in  the  mortar  first  and  soften  it  with  a  few  drops  of 
syrup,  and  add  the  medicinal  ingredients  to  it. 
