ethylcellulose

Ethylcellulose is a cellulose ether obtained by etherification of cellulose with ethyl groups. It is a hydrophobic, water-insoluble polymer that readily forms clear, flexible films when dissolved in volatile organic solvents and cast or melted. It is used as a film-forming agent, binder, and thickener in a range of applications and is valued for its chemical stability and water resistance.

The production involves reacting cellulose with ethylating agents such as ethyl chloride or ethyl sulfate in the presence of a base or catalyst. The resulting polymer has ethyl substitutions on its glucose units, giving solubility in many organic solvents (for example acetone, ethyl acetate, and toluene) while remaining largely insoluble in water. It is thermoplastic and shows a relatively high glass-transition temperature, depending on substitution degree and molecular weight.

In pharmaceuticals, ethylcellulose is used to coat tablets and capsules to mask taste and to control the release of active ingredients. It is also employed as a film-forming polymer in other solid dosage forms and in some parenteral coatings. In industry more broadly, it serves as a film-former, binder, and thickener in paints, varnishes, inks, and cosmetics, and is used in encapsulation and as a waterproofing component.

Safety and regulation: Ethylcellulose is generally regarded as non-toxic and chemically inert at typical use levels. It is widely employed as a pharmaceutical excipient and, in some jurisdictions, as a food additive. Proper handling is advised to minimize inhalation of powder dust.