Presentation Transcript
Tablet Coating :Tablet Coating Why coat tablets?
Types of coatings
sugar coating
film coating
press coating (compression coating)
Sugar Coating :Sugar Coating stages involved
sealing of tablet core
subcoating
smoothing
colouring
polishing
printing
Film Coating :Film Coating involves spraying a solution of polymer + pigments + plasticizers onto a rotated, mixed tablet bed
forms a thin, uniform film on tablet surface
materials
polymers
solvents
plasticizers
colorants
Film Formation :Film Formation latex particles dispersed
in aqueous phase formation of thin film with
water evaporation through film continuous film
Coating Process :Coating Process coating pans
Coating Process :Coating Process fluid beds
Important Processing Parameters :Important Processing Parameters inlet and bed temperatures
relative humidity
atomization air pressure
liquid spray rate
droplet size
drying time
Coating Problems :Coating Problems picking/chipping
roughness
sticking
film cracking/peeling
Normal Coating :Normal Coating
Enteric-coated :Enteric-coated coating resists dissolution or disruption in stomach but not in intestines
used for drugs that are unstable, irritating to stomach
Enteric Coating :Enteric Coating
Press Coating :Press Coating use of compression to form coat around a pre-formed core
used mainly to separate chemically incompatible materials
also dual release patterns possible