Hydroxypropyl methyl cellulose

Absorption

Not systemically absorbed .

Toxicity

LD 50 (Rat): > 5 g/kg .
Hypromellose is considered low toxicity to non-toxic .
Adverse events may include blurred vision and contact dermatitis . Hypersensitivity and intolerance reactions may occur (for example, eye burning, pain, increased lacrimation, a sensation of foreign body, conjunctival hyperemia, eyelid swelling, pruritus). The stickiness sensation of the eyelids, the decreased sense of smell, photosensitivity .

Description

Hydroxypropyl methyl cellulose is a propylene glycol ether of methylcellulose in which both hydroxypropyl and methyl groups are bound to the anhydrous glucose ring of cellulose by ether linkages. Hydroxypropyl methyl cellulose is synthesized from methyl cellulose by the action of alkali and propylene oxide. The resultant product is a water soluble ether derivative of cellulose containing both methoxy and hydroxypropyl groups. The degree of substitution is 1.08 to 1.83 with the hydroxypropyl groups as the minor constituent. White to off-white fibrous powder or granules. Soluble in water and some organic solvents. Insoluble in ethanol, the aqueous solution has surface activity, forms a thin film after drying, and undergoes a reversible transition from sol to gel in turn by heating and cooling.

The Uses of Hydroxypropyl methyl cellulose

Hydroxypropyl Methylcellulose is a gum formed by the reaction of propylene oxide and methyl chloride with alkali cellulose. it will gel as the temperature is increased in heating and upon cooling will liquefy. the gel temperature ranges from 60°c to 90°c, forming semifirm to mushy gels. it is used in bakery goods, dressings, breaded foods, and salad dressing mix for syneresis control, texture, and to provide hot viscosity. usage level ranges from 0.05 to 1.0%.

Background

Hypromellose, or hydroxypropyl methylcellulose (HPMC) , is a semisynthetic, inert, and viscoelastic polymer that forms a colloid solution when dissolved in water. It acts as a thickening agent, coating polymer, bioadhesive, solubility enhancer in solid dispersions, and binder in the process of granulation and in modified release formulations . It is a commonly used as a delivery component in oral pharmaceutical products that provides the release of a drug in a controlled fashion, effectively increasing the duration of release of a drug to prolong its therapeutic effects . Hypromellose is also found in eye drops as a lubricant .

What are the applications of Application

(Hydroxypropyl)methyl cellulose is a thickener for aqueous and non-aqueous systems

Indications

Used as an ophthalmic protectant and lubricant, in artificial tears, and as a diagnostic aid (contact lens procedures; gonioscopy).

Pharmacokinetics

Hypromellose is the most commonly used in hydrophilic matrix fabrication. It allows for controlled release of drug substances, increasing duration of therapeutic effects . The physical characteristics of this drug resemble natural tears, providing lubrication to the ocular surface and maintaining corneal hydration in dry eye syndromes .
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 and epithelial cells .
Hypromellose is a methyl and hydroxypropyl mixed ether of cellulose. It is utilized as artificial tears to prevent conjunctival and corneal damage due to impaired lacrimal secretions. It is also used as a visco-elastic promoting agent by maintaining a deep, viscous chamber and allowing for easier manipulation, helping the vitreous surface to be pushed back, thus preventing the formation of a postoperative flat chamber .

Metabolism

Not Available