76 
Pills  and  Pill  Coatings. 
Am.  Jour.  Pharm. 
Feb.,  1878. 
single  drop  of  water.  Camphor  and  extract  of  henbane  usually  form 
a  very  refactory  mass,  breaking  and  crumbling  on  the  machine  ;  if,  how- 
ever, the  camphor  is  powdered  by  the  addition  of  a  little  water  instead 
of  spirit,  all  difficulty  disappears,  the  mass  retains  its  plastic  condition 
for  some  time,  and  might  be  rolled  out  with  perfect  ease. 
Whatever  means  are  used  for  the  formation  of  pills,  they  should, 
when  finished,  be  perfectly  spherical  and  present  a  smooth,  firm  sur- 
face \  this  is  essential,  not  only  for  the  sake  of  appearance,  but  for  the 
proper  performance  of  the  second  operation,  viz.,  that  of  coating  them. 
Reading  a  short  extract  from  the  "  United  States  Dispensatory,"  of 
1833,  will  prove  that  even  America,  which  has  gone  ahead  so  rapidly 
in  pill  coating  as  in  most  other  things,  contemplated  nothing  of  the 
kind  in  those  days.  The  method  of  covering  pills  with  powders  as 
there  described  was  that  which  obtained  in  this  country  during  my 
early  initiation  into  the  art  and  science  of  pharmacy  some  twenty  years 
or  more  ago  \  indeed,  it  is  still  practised  in  many,  if  not  most  phar- 
macies in  the  present  day,  a  little  of  the  powder  also  being  placed  in 
the  box  to  keep  the  pills  at  a  respectful  distance  from  each  other.  The 
first  improvementon  this  with  which  I  becameacquainted  was  that  adopted 
by  myself  in  i860;  possibly  the  same  or  similar  methods  might  have 
been  in  use  at  the  same  time  by  others,  but  as  far  as  myself  was  concerned, 
it  was  original  (at  least  as  original  as  ideas  ever  are),  and  very  simple  too. 
It  consisted  in  utilizing  a  waste  product,  viz.,  the  resin  left  after  prepar- 
ing syrup  of  tolu  ;  this,  dissolved  in  ether,  preferably  with  a  sp.  gr.  of 
•717  or  '720,  formed  a  varnish  in  which  the  pills  were  rolled  and 
whilst  still  moist  were  transferred  to  a  box  containing  finely  powdered 
French  chalk,  then  turned  on  to  a  warm  pill  tray  and  kept  rotating  for 
a  short  time  \  finally  they  were  polished  with  slight  pressure  under  the 
pill  finisher.  Pills  so  prepared  possess  a  steel  grey  appearance  and 
smooth  surface,  though  not  the  egg-shell  white  character  now  given 
them  ;  but  this  method  of  procedure  or  some  modification  of  it  is  the 
first  part  of  the  process  adopted  for  accomplishing  the  latter. 
'  The  pills  are  now  placed  in  a  covered  pot  as  at  first,  and  are  mois- 
tened with  syrup,  mucilage  or  a  mixture  of  the  two  ;  when  evenly 
covered  they  are  transferred  to  a  box  containing  French  chalk,  or  a 
mixture  of  it  and  finely  powdered  sugar,  well  shaken  and  again  trans- 
ferred to  a  warm  pill  tray,  kept  rapidly  rotating  until  dry  and  smooth  ; 
the  operation  taking  but  a  comparatively  short  time.    Well  covered  in 
