Film-Forming Polymers
Cellulose derivatives: Hydroxypropyl methylcellulose (HPMC), ethylcellulose, cellulose acetate.
Methacrylic polymers: Eudragit series.
Enteric polymers: Cellulose acetate phthalate (CAP), polyvinyl acetate phthalate (PVAP), HPMCP.
Plasticizers
Enhance film flexibility, reduce brittleness.
Examples: Glycerin, propylene glycol, triethyl citrate.
Colorants & Opacifiers
Provide aesthetic appearance, identification, or protect from light.
Examples: Titanium dioxide (opacifier), iron oxides (pigments).
Solvents
Organic solvents: Acetone, ethanol, isopropanol (less preferred due to toxicity, flammability, environmental concerns).
Aqueous systems: Water-based dispersions or solutions.