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.