1) Pan Coating (Rotary Drum):
Process: Tablets rotate in a drum while coating solution is sprayed and dried.
Advantages: Simple, widely used, works for aqueous and non-aqueous coatings.
Disadvantages: Limited thickness control, risk of uneven coating in large batches.
2) Fluidized Bed Coating:
Process: Tablets are suspended in an air stream, sprayed with coating, and dried simultaneously.
Advantages: Uniform coating, precise thickness control, energy-efficient drying.
Disadvantages: Expensive equipment, risk of tablet breakage.
3) Spray Drying:
Process: Coating is atomized into droplets, dried, and adhered to tablets.
Advantages: Rapid drying, suitable for heat-sensitive drugs.
Disadvantages: High energy use, limited scalability.
4) Electrostatic Coating:
Process: Tablets and coating particles are charged electrostatically for even application.
Advantages: Precise coating, minimal waste.
Disadvantages: Requires specialized equipment, less common for large batches.
5) Vacuum Coating:
Process: Coating materials are vaporized and deposited in a vacuum chamber.
Advantages: Solvent-free, uniform coating.
Disadvantages: High cost, limited scalability.