Hypromellose

Category

Bioadhesive Material; Coating Agents; Controlled-release Agents; dispersing Agents; Emulsifying Agents; Emulsion Stabilizer; extended-release Agents; Film-forming Agents; foaming Agents; Granulation Aid; modified-release Agents; mucoadhesive;

Grade

Pharmceutical Excipients

UNII

B1QE5P712K

Chemical Name

Cellulose hydroxypropyl methyl ether

CAS Number

9004-65-3

Synonyms

Benecel MHPC; E464; hydroxypropyl methylcellulose; HPMC; hypromellosum; Methocel; methylcellulose propylene glycol ether; methyl hydroxypropylcellulose; Metolose; MHPC; Pharmacoat; Tylopur; Tylose MO

Administration route

Ophthalmic and nasal; oral

Dosage Form

Ophthalmic and nasal preparations; oral capsules, suspensions, syrups, and tablets

Stability and Storage Conditions

Hypromellose powder is a stable material, although it is hygroscopic after drying. Solutions are stable at pH 3-11. Hypromellose undergoes a reversible sol-gel transformation upon heating and cooling, respectively. The gelation temperature is 50-90℃, depending upon the grade and concentration of material. For temperatures below the gelation temperature, viscosity of the solution decreases as temperature is increased. Beyond the gelation temperature, viscosity increases as temperature is increased. Aqueous solutions are comparatively enzyme-resistant, providing good viscosity stability during long-term storage. However, aqueous solutions are liable to microbial spoilage and should be preserved with an antimicrobial preservative: when hypromellose is used as a viscosity-increasing agent in ophthalmic solutions, benzalkonium chloride is commonly used as the preservative. Aqueous solutions may also be sterilized by autoclaving; the coagulated polymer must be redispersed on cooling by shaking. Hypromellose powder should be stored in a well-closed container, in a cool, dry place.

Commonly used amount and the maximum amount

A purified form of cellulose, obtained from cotton linters or wood pulp, is reacted with sodium hydroxide solution to produce a swollen alkali cellulose that is chemically more reactive than untreated cellulose. The alkali cellulose is then treated with chloromethane and propylene oxide to produce methyl hydroxypropyl ethers of cellulose. The fibrous reaction product is then purified and ground to a fine, uniform powder or granules. Hypromellose can then be exposed to anhydrous hydrogen chloride to induce depolymerization, thus producing low viscosity grades.

Applications

Hypromellose is widely used in oral, ophthalmic, nasal, and topical pharmaceutical formulations. In oral products, hypromellose is primarily used as a tablet binder, in film-coating, and as a matrix for use in extendedrelease tablet formulations.

Safety

Hypromellose is widely used as an excipient in oral, opthalmic, nasal, and topical pharmaceutical formulations. It is also used extensively in cosmetics and food products. Hypromellose is generally regarded as a nontoxic and nonirritating material, although excessive oral consumption may have a laxative effect. The WHO has not specified an acceptable daily intake for hypromellose since the levels consumed were not considered to represent a hazard to health. In fact, high dosages of hypromellose are being investigated for treating various metabolic syndromes. LD50 (mouse, IP): 5 g/kg LD50 (rat, IP): 5.2 g/kg

Incompatibilities

Hypromellose is incompatible with some oxidizing agents. Since it is nonionic, hypromellose will not complex with metallic salts or ionic organics to form insoluble precipitates.

cid3

20150