594 
Ointment  of  Salicylic  Acid. 
Am.  Jour.  Pharm- 
Nov,  1884. 
AN  IMPROVED  METHOD  OF  PREPARING  OINTMENT 
OF  SALICYLIC  ACID. 
By  Balmanno  Squire,  M.B., 
Surgeon  to  the  British  Hospital  for  Diseases  of  the  Skin. 
Salicylic  acid  ointment  is  now  largely  used,  not  only  as  a  dressing  to 
surgical  wounds  in  the  "  antiseptic  "  or  "  Lister  "  treatment  of  them, 
but  also  as  a  local  remedy  in  one  of  the  commonest  of  the  diseases  of 
the  skin,  namely  in  eczema.  Any  improvement  in  its  mode  of  manu- 
facture may  therefore  prove  a  general  advantage. 
I  find  that  salicylic  acid  is  soluble  in  hot  lard  (at  water- bath 
temperature)  in  about  the  proportion  in  which  it  is  usually  prescribed, 
that  is  to  say  at  the  rate  of  thirty  grains  of  the  acid  to  an  ounce  of 
lard.  I  mention  this  fact  because  I  have  before  ventured  in  this 
Journal  to  suggest  to  pharmacists  a  systematic  investigation  on  their 
part  of  the  solubility  of  ointment  remedies  in  hot  lard,  and  on  this 
ground,  namely,  that  I  find  as  a  matter  of  my  own  experience  that  a 
remedy  which  has  undergone  solution  in  the  lard  that  it  is  prescribed 
with  is  much  more  vigorous  in  its  action  on  the  skin  or  on  a  wound 
than  when  it  has  been  merely  mixed  with  cold  lard ;  the  ointment  be- 
comes also  of  better  appearance,  although  that  is  a  minor  matter. 
In  the  case  of  chrysophanic  ointment,  I  suggested  that  after  its  pre- 
paration by  solution  of  the  acid  in  hot  lard  the  ointment  should,  after 
cooling,  be  well  mixed  with  the  pestle  and  mortar  on  account  of  the 
tendency  of  the  particles  of  the  acid  (minutely  precipitated  during  the 
cooling  of  the  ointment)  to  collect  towards  the  surface,  more  especially 
at  the  edges  of  the  surface. 
I  observe  that  the  same  phenomenon  occurs  during  the  cooling  of 
salicylic  ointment  that  I  have  noted  in  the  case  of  chrysophanic  oint- 
ment, so  that  the  pestle  and  mortar  are  here  also  necessary  to  finish 
the  manufacture  of  the  ointment  by  the  solution  method. 
In  the  treatment  of  any  disease  of  the  skin,  the  minutest  possible 
division  of  any  remedy  employed  in  the  state  of  ointment  is  an  ad- 
vantage which  will  promptly  disclose  itself  to  any  cne  who  may  choose 
to  experiment  on  the  question;  but  in  the  matter  of  antiseptic  applica- 
tions to  wounds,  where  the  aim  is  to  exclude  by  means  of  a  specially 
composed  ointment  the  access  of  infinitesimal  germs,  such  an  advantage 
must  perhaps  be  of  still  higher  value.    I  have  never  been  able 
