Cellulose Acetate USP/NF, EP

Cellulose acetate is a cellulosic polymer in which a portion or all of the hydroxyl groups are acetylated. It is prepared from highly purified cellulose by treatment with acid catalysis and acetic anhydride and occurs as a white, odourless, tasteless, free flowing powder.

Cellulose acetate is used as a semi-permeable coating on tablets, especially on osmotic pump-type tablets and implants allowing for controlled-release of the actives. Cellulose acetate films, in conjunction with other materials, also offer sustained release without the necessity of drilling a hole in the coating as is typical with osmotic pump systems. Cellulose acetate and other cellulose esters have also been used to form drug loaded micro-particles with controlled-release characteristics.