Am.  Jour.  Pharm. 
November,  1897. 
Official  Lead  Preparations, 
575 
CERATUM  PLUMBI  SUBACETATIS. 
Probably  one  of  the  most  unsatisfactory  official  preparations  used 
for  inunction  is  Goulard's  cerate. 
Its  liability  of  becoming  rancid  in  a  comparatively  short  time  is  a 
source  of  annoyance  to  many  pharmacists  who  are  compelled  to 
keep  a  stock  of  the  cerate  on  hand. 
The  alkaline  nature  of  the  lead  subacetate  solution  has  the  ten- 
dency to  saponify  the  fat  employed,  and  in  our  older  text-books  on 
pharmacy  the  statement  is  found  that  a  kind  of  lead  soap  is  formed. 
Continental  pharmacopoeias  endeavor  to  overcome  this  difficulty 
by  the  substitution  of  paraffin  ointment  bases  for  animal  or  vege- 
table fats,  changing  the  preparation  from  the  nature  of  a  cerate  to 
that  of  an  ointment. 
But  in  the  employment  of  petrolatum  and  similar  ointment  bases 
one  of  the  most  important  objects  of  Goulard's  cerate,  its  cooling 
property,  is  impaired,  and  this  substitution  is,  therefore,  of  doubtful 
value. 
The  following  is  the  official  formula  : 
Mix  them  thoroughly. 
This  cerate  should  be  freshly  prepared  when  wanted  for  use. 
The  Pharmacopoeia  gives  the  operator  no  special  directions  how 
to  mix  the  cerate. 
Mixing  without  melting,  with  the  usual  method  of  incorporation 
with  a  spatula  on  an  ointment  slab,  is  doubtlessly  to  be  understood. 
It  is  questionable,  however,  if  this  method  is  exclusively  followed, 
especially  when  large  quantities  of  the  cerate  are  prepared. 
The  ease  and  rapidity  of  incorporating  the  subacetate  solution 
with  the  melted  cerate  is  too  tempting,  particularly  if  the  Pharma- 
copoeia does  not  furnish  prohibitory  directions. 
It  is  obvious  that  the  stated  saponification  is  more  liable  to  occur 
by  the  employment  of  this  process  than  where  mixture  without  heat 
is  effected. 
An  objectionable  feature  of  animal  fats  in  this  preparation  lies  in 
the  production  of  a  yellow  or  reddish  color  on  standing.  This  is 
not  only  likely  to  occur  in  the  stock  jar  of  the  pharmacist,  but  in 
the  ointment  container  of  the  patient  as  well,  frequently  giving  rise 
to  unpleasant  suspicions. 
Grammes. 
Solution  of  lead  subacetate 
Camphor  cerate  
200 
800 
