Cellulose acetate phthalate

Cellulose acetate phthalate (CAP, also known as cellacefate) is a cellulose-derived polymer produced by esterifying cellulose acetate with phthalic anhydride. It carries no E-code designation. It is identified by CAS 9004-38-0 and EC 618-382-8.

CAP is used primarily as an enteric coating agent in solid oral dosage forms, where its pH-dependent solubility keeps tablet or capsule coatings intact in gastric acid but allows dissolution in the higher pH of the small intestine. It also functions as a film-forming binder in controlled-release granule systems, modifying surface wettability to regulate drug release profiles.

CAP is available as a white granular powder conforming to Ph.Eur. and USP-NF monograph specifications, making it suitable for pharmaceutical manufacturing under GMP conditions. It is subject to REACH registration requirements within the EU. Procurement quantities and packaging formats are available on request from our sales team.