Hydroxypropyl Cellulose

Synonyms: Cellulose, hydroxypropyl ether; E463; hydroxypropylcellulosum; hyprolose; Klucel; Nisso HPC; oxypropylated cellulose.

Description:  Hydroxypropyl cellulose is a white to slightly yellow-colored, odorless and tasteless powder.

Chemical Name: Cellulose, 2-hydroxypropyl ether

Complexing agent; dissolution enhancer; release-modifying agent; sequestering agent; solubilizing agent; stabilizing agent; tonicity agent.

• Hydroxypropyl cellulose is widely used in oral and topical pharmaceutical formulations

• In oral products, hydroxypropyl cellulose is primarily used in tableting as a binder, film-coating, and extended-release-matrix former.

• Concentrations of hydroxypropyl cellulose of 2–6% w/w may be used as a binder in either wet-granulation or dry, directcompression tableting processes.

• Concentrations of 15–35% w/w of hydroxypropyl cellulose may be used to produce tablets with an extended drug release.

• The release rate of a drug increases with decreasing viscosity of hydroxypropyl cellulose.

• The addition of an anionic surfactant similarly increases the viscosity of hydroxypropyl cellulose and hence decreases the release rate of a drug.

• Blends of hydroxypropyl cellulose and other cellulosic polymers have been used to improve wet granulation characteristics and tableting characteristics, as well as to achieve better control and manipulation of the rate of drug release.

• As an alternative technology to wet granulation, dry granulation and direct compression of hydroxypropyl cellulose formulations have been reported to exhibit acceptable tableting and flow characteristics for application in extended-release matrix tablets.

• Typically, a 5% w/w solution of hydroxypropyl cellulose may be used to film-coat tablets.

• Aqueous solutions containing hydroxypropyl cellulose together with an amount of methyl cellulose or ethanolic solutions have been used.

• Stearic acid or palmitic acid may be added to ethanolic hydroxypropyl cellulose solutions as plasticizers.

• Environmental concerns have limited the use of ethanol in film coating solutions.

• A low-substituted hydroxypropyl cellulose is used as a tablet disintegrant; see Hydroxypropyl Cellulose, Low-substituted.

• Hydroxypropyl cellulose is also used in microencapsulation processes and as a thickening agent.

• In topical formulations, hydroxypropyl cellulose is used in transdermal patches and ophthalmic preparations.

• Hydroxypropyl cellulose is also used in cosmetics and in food products as an emulsifier and stabilizer.

Hydroxypropyl cellulose in solution demonstrates some incompatibility with substituted phenol derivatives, such as methylparaben and propylparaben. The presence of anionic polymers may increase the viscosity of hydroxypropyl cellulose solutions. The compatibility of hydroxypropyl cellulose with inorganic salts varies depending upon the salt and its concentration; see Table VI. Hydroxypropyl cellulose may not tolerate high concentrations of other dissolved materials.

Hydroxypropyl cellulose is widely used as an excipient in oral and topical pharmaceutical formulations. It is also used extensively in cosmetics and food products. Hydroxypropyl cellulose is generally regarded as an essentially nontoxic and nonirritant material. It is not absorbed from the gastrointestinal tract and is fully recovered in feces after oral administration in rats. It does not exhibit skin irritation or skin sensitization. However, the use of hydroxypropyl cellulose as a solid ocular insert has been associated with rare reports of discomfort or irritation, including hypersensitivity and edema of the eyelids. Adverse reactions to hydroxypropyl cellulose are rare. However, it has been reported that a single patient developed contact dermatitis due to hydroxypropyl cellulose in a transdermal estradiol patch

Observe normal precautions appropriate to the circumstances and quantity of material handled. Hydroxypropyl cellulose dust may be irritant to the eyes; eye protection is recommended. Excessive dust generation should be avoided to minimize the risk of explosions.

Hydroxyethyl cellulose; hydroxypropyl cellulose, low-substituted; hypromellose.