Hypromellose is a semisynthetic, inert, viscoelastic methyl and hydroxypropyl mixed ether of cellulose used as eye drops, as well as an excipient and controlled-delivery component in oral medicaments, found in a variety of commercial products. Hypromellose is considered an inert substance as it has no direct pharmacological activity. The viscosity promoting properties of hypromellose prolong the retention time and improve adhesion of synthetic tears to the cornea and conjunctiva. As a result, the tear film breakdown time is prolonged and/or the tear film stability is enhanced. A stable tear film protects the cornea from dryness Hypromellose is the most commonly used in hydrophilic matrix fabrication. Hypromellose provides the release of a drug in a controlled manner, effectively increasing the duration of release of a drug to prolong its therapeutic effect.

Cellacefate is a commonly used polymer phthalate in the formulation of pharmaceuticals, such as the enteric coating of tablets or capsules and for controlled release formulations. Cellacefate's use in enteric coatings allows tablets to remain intact in the unfavorable gastric acid secretion of the stomach, but dissolve in the more basic areas of the duodenum, thus protecting the stomach from ulceration or allowing greater absorption form the duodenum. Cellacefate is a reaction product of phthalic anhydride and a partial acetate ester of cellulose.