The motivation for applying film coatings to dosage forms range from cosmetic considerations (colour, gloss and branding), improving the shelf life by providing a protective barrier between the drug and the surrounding environment.
[1] The spraying phase consists of applying a layer of a polymer, plasticizer, colourant, opacifier, solvent, and a vehicle to the oral dosage form's core.
The final result is a thin film coating with the desired plasticizer, colour, opacifier, and vehicle.
[1] Non-functional film coating involves changes made to the aesthetic of the oral dosage form.
[1] The result is a safer means of film coating, as it avoids the toxic and flammable properties of organic solvents.
Aqueous film coating requires the use of water insoluble polymer mixtures, with the addition of a plasticizer.
[1] Each method has its own advantages and disadvantages, but the common theme amongst them is the need for very precise conditions that can satisfactorily apply a film coating to the oral dosage form.