in Pharmacy by (275 points)
film coating done for mask the bitter taste of drug in this question require to give methods of film coating.

1 Answer

by (2.3k points)
  1. Film coating for tablets are done by two methods.
  1. Pan Coating: Different types of pans are used for the coating of tablets. The coating solution spray with nozzle and tablets are taken in rotating pan. Due to maintain temperature spray nozzle and rotation of pan form a proper layer of film on tablets.
  2. Fluidized bed coating: this is advanced technique for tablets as well as granules this high pressure air supplied from bottom of chamber and maintain fuidized state f tablets and granules. Top position adjusts the nozzle droplets for coating. Spreading and drying simultaneously done.  

Process variables:

Pan variables: pan desire (Circular), Shape of tablets (circular, spherical oval), speed (RPM),  load

Spray variable: Nozzle size decides the droplets size, Nozzle height.

  • Automization: Conversion of solution to droplets
  • Size of nozzle
  • Air capacity
  • Pressure

Spreading: Based on gun distance and width of gun nozzle

Distance between nozzle and tablets: If increase the distance cause dry the droplets before reach the tablet cause roughness. If decrease the distance cause over wetting of tablets.

Process air variables:

  • Air volume
  • Temperature
  • Capacity of container