Table 5.

Summary of coating techniques.

Coating Techniques	Advantages	Disadvantages
Physical Method
Rotary Drum	• Can be a continuous process, low operating cost, easily scaled	• Requires a large number of materials to achieve a uniform coating
Pan Coating	• Can be a continuous process, low operating cost, easily scaled	• High air temperature for drying • Poor maintenance of humidity level results in a defective structure
Fluidized Bed	• Can be a continuous process, low operating cost, easily scaled • Can achieve a more uniform coating • A more extensive selection of materials	• Expensive equipment • Long residence time • Prone to filter blocking • Higher chance of solvent explosion • Lower performance with larger granule size
Melting and Extrusion	• Solvent-free • Simple and cheap	• Hot melts are involved • Expensive equipment
Chemical Method
Solution Polymerization/crosslinking	• Solvent reduces viscosity which makes it easier to process. • Crosslinking density can be controlled by varying monomer, initiator and cross-linking agent content	• Lower rate of reaction results in possible loss of compound • Difficult to recover solvent from its final form.
Inverse Suspension Polymerization	• Crosslinking density can be controlled by varying monomer, initiator and cross-linking agent content • Higher efficiency due to high reaction rate • The solvent can be recovered which reduces the cost	• Prone to contamination by the suspension • Must perform separation to purify polymer
Microwave Irradiation	• Simple and low energy consumption	• Not widely implemented in CRF preparation