Tablet Coating Why coat tablets? Types of coatings  sugar coating  film coating  press coating (compression coating) B. Amsden1CHEE 440

Sugar Coating stages involved:  sealing of tablet core  subcoating  smoothing  colouring  polishing  printing B. Amsden2CHEE 440

Film Coating Involves spraying a solution of polymer + pigments + plasticizers onto a rotated, mixed tablet bed to form a thin, uniform film on tablet surface. materials  polymers  solvents  plasticizers  colorants B. Amsden3CHEE 440

Coating Process coating pans B. Amsden4CHEE 440

The Coating Process B. AmsdenCHEE 4405

Film Formation latex particles dispersed in aqueous phase formation of thin film with water evaporation through film continuous film B. Amsden6CHEE 440

Air Flow B. AmsdenCHEE 4407

Coating Process fluid beds B. Amsden8CHEE 440

Important Processing Parameters inlet and bed temperatures relative humidity atomization air pressure liquid spray rate droplet size drying time B. Amsden9CHEE 440

Coating Problems picking/chipping roughness sticking film cracking/peeling B. Amsden10CHEE 440

Normal Coating B. Amsden11CHEE 440

Enteric-coated Coating resists dissolution or disruption in stomach but not in intestines. Used for drugs that are unstable, irritating to stomach B. Amsden12CHEE 440

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 B. Amsden13CHEE 440