Ethyl cellulose, which is insoluble in water but soluble in various organic solvents, is commonly used as a binder for tablets and granules. It increases tablet hardness and reduces friability. When applied as a thin film coating—only 10–30 µm thick—it can serve as a film-forming agent to improve tablet appearance, mask taste, protect water-sensitive drugs from degradation, prevent moisture absorption and deterioration, and enhance storage stability. Additionally, it can be used as a matrix material in sustained-release formulations such as matrix tablets, pellets, and microcapsules, providing controlled drug release by acting as a barrier to diffusion.