Hydroxypropyl methyl cellulose Chemical Description
Product features
Hydroxypropyl methyl cellulose is propylene glycol ether of methyl cellulose, hydroxypropyl and methyl combine with anhydrous glucose ring by ether bond.It is white or pale white cellulose powder or particles. The characteristics of cold water dissolution and hot water insoluble are similar with methyl cellulose. Solubility in organic solvents is superior than water soluble, can be dissolved in anhydrous methanol and ethanol solution, also soluble in chlorinated hydrocarbons and ketones in organic solvents. Soluble in water, its water solution has a surface activity, the formation of the film after drying, heated and cooled, in turn, from the reversible conversion of sol to gel. Can be used alone in the cold drink, also can be used with other emulsifier, stabilizer. To cold drink, the maximum amount is 1%. Hydroxypropyl methyl cellulose and other water-soluble high weight compounds use mixture, become transparent, higher viscosity. The gelation temperature of low viscosity products is higher than high viscosity of products. Its solution is stable at room temperature. In recent years, It has been widely used in petroleum chemical industry, papermaking, leather, textile printing and dyeing, pharmaceutical, food, cosmetics and other industries, and as the dispersing agent, thickening agent, adhesive, excipient, capsule, oil resistant coating and packing etc.
Usage method
Purpose: thickener, emulsifier, stabilizer.
1 note: hydroxypropyl methyl cellulose has many excellent properties. It can be used for baking food, pasty food, enriched food, milk paste mixing drinks, pie fillings, toppings, salad and fast food. The use of its thermal gel properties can make deep fried food, not only can save a lot of oil, but also the product has a unique taste of the soft. The use of its acid, alkali stability, anti-enzymes, do not participate in metabolism, enhance the characteristics of gastrointestinal motility, but also used to produce a variety of health food.
2 usage range and usage
(1) The provisions on the use of hygienic standards for food additives (GB 2760-1996) shall be used in all kinds of food appropriately.
(2) The actual use of reference: the use of high transparency film and film of this product can be used in the manufacture of casings, dosage is 5%. It is used as a thickener mayonnaise (HPMC-60RT400), dosage of 0.5%~2%.
Ophthalmic remedy
[Application] Through the stability and thickening of anterior corneal tear, it can promote corneal moist, cut off time, extend the tear film in dry eyes and can prolong the retention time of tear film. It used for the lack of clinical tear caused by dry eyes and eye irritation, and the treatment of keratoconjunctivitis sicca, exposure keratitis and Neuroparalytic keratitis to prevent corneal injury. It can be used for hard contact lenses or artificial eye lubricant. For gonioscopy, contact endoscopy and surgery, it is as a medium in condensation genioplasty or retinal laser iridectomy in the process to protect the cornea.
[dosage] eye: 0.3%~1% solution, 1 drops, 3~4 times /d. 2% of the solution is used for the anterior chamber angle.
[Attention and taboo] Using it can sometimes have blurred vision or eyelid adhesion feeling. Continuous time should not exceed 3 Days. Wearing soft contact lens is banned to corneal epithelial disease. Wear a hard contact lens should prevent the lens floating.
[Specification] eye drops: 0.3%, 0.5%, 1%, 2.5%.
This information is edited by Chemicalbook Xiannan (2015-08-31).
Identification test
It is soluble in water swelling, forming a transparent milky white sticky gel solution, and insoluble in ethanol.
Toxicity
ADI does not make special provisions (FAO/WHO, 2001). It can be used for food safety (FDA. §172.87, 2000). LD505200mg/kg (rats, intra peritoneal injection).
Limited use
FAO/WHO (1984): Cold drink ,10g/kg (in the end product design, single use or with other emulsifier, stabilizer and thickener dosage).
GB 2760-96: all kinds of food, to GMP limited.
Chemical property
Hydroxypropyl methyl cellulose is propylene glycol ether of methyl cellulose, hydroxypropyl and methyl combine with anhydrous glucose ring by ether bond.It is white or pale white cellulose powder or particles.It has different types of products, the methoxy and hydroxypropyl content ratio is different. It is white or gray fibrous powder or particles. It is soluble in water and some organic solvents and unsoluble in ethanol. Aqueous solution has a surface activity, the formation of the film after drying, heated and cooled, in turn, from the sol to gel reversible transformation.
Uses
1. Thickener, stabilizer, emulsifier, emulsifier, suspending agent.
2. It is used as a synthetic resin dispersing agent, and the coating agent,also used as a thickener.
3. This product is used as a thickener, dispersant, binder, emulsifier and stabilizer in the textile industry. It is also widely used in synthetic resin, petrochemical, ceramics, paper, leather, medicine, food, cosmetics and other industries.
4. Used in synthetic resin, petroleum chemical industry, ceramics, paper, leather, textile, medicine, food, cosmetics and other daily chemicals and as dispersing agent, thickening agent, binders, excipients, capsules, oil resistant coating and packing etc.
Methods of production
1.The refined cotton cellulose with alkali treatment at 35-40 ℃ for half an hour, press, crushed the cellulose, aging at 35 ℃, so that the average degree of polymerization of alkali cellulose is in a desired range. The alkali fiber into etherification reactor, followed by adding epoxy propane and methane chloride, etherification at 50-80 ℃ for 5h, the maximum pressure is about 1.8MPa. The reaction products were produced by postprocessing (hydrochloric acid and oxalic acid, washing and drying). The consumption of raw material of cotton pulp 1100kg/t, methyl chloride and propylene oxide 4300kg/t, solid alkali 1200kg/t, hydrochloride 30kg/t, oxalic acid 50kg/t.
2.100 kg refined cotton linters immersed in 45% solution, temperature is 35 to 40℃, time is 0.5 to 1 h, and then remove the press. The pressure to weight is 2.7 times as the weight of lint, stop pressure. Carry out the crushing. At 35℃, aging for 16h.
In the reaction kettle, the chlorinated methane, propylene oxide were added into the reaction kettle. At 80℃, the pressure was 1.8 MPa, the reaction time is 5 to 8 h, and the amount of hydrochloric acid and oxalic acid were added to the hot water at 90℃. Dewatering with centrifuge, washing to neutral, when the water content of the material is below to 60% , 130℃ of hot air flow dried to the moisture content is below 5%. Finally, the finished product sieved by 20 mesh.
3. Prepared by cellulose, methyl chloride, and ethylene oxide.
Description
Cellulose is a natural substance normally present in most diets because it is the major structural carbohydrate of green plants. Cellulose is essentially a linear polymer of glucopyranose units connected by (3-1,4-glucoside links. In nature, cellulose is present in plant cell walls as fibers. The molecular weight of isolated cellulose is approximately 50,000. The principal sources of cellulose for food related purposes are cotton linters and wood pulp. Chemical processing converts cellulose into forms or derivatives suitable for incorporation into food products, or for use in food packaging materials. Hydroxypropylmethyl 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. It is used as a thickening agent, stabilizer, and emulsifier.
Chemical Properties
white or slightly beige powder or a viscous solution
Chemical Properties
Hypromellose is an odorless and tasteless, white or creamy-white fibrous or granular powder.
Uses
Thickener for aqueous and non-aqueous systems, clear films with grease resistance, binders, lubricants, steric stabilizer and water retention aid.
Uses
A thickener for aqueous and non-aqueous systems.
Uses
As emulsifier, film former, protective colloid, stabilizer, suspending agent, or thickener in foods. Pharmaceutic aid (suspending agent; tablet excipient; demulcent; viscosity increasing agent); hydrophilic carrier in drug delivery systems. In adhesives, asphalt emulsions, caulking compounds, tile mortars, plastic mixes, cements, paints.
Uses
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%.
Production Methods
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.
Pharmaceutical 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. Concentrations between 2% and 5% w/w may be used as a binder in either wet- or dry-granulation processes. High-viscosity grades may be used to retard the release of drugs from a matrix at levels of 10–80% w/w in tablets and capsules. Hypromellose is also used in liquid oral dosage forms as a suspending and/or thickening agent at concentrations ranging from 0.25–5.0%.
Depending upon the viscosity grade, concentrations of 2–20% w/w are used for film-forming solutions to film-coat tablets. Lowerviscosity grades are used in aqueous film-coating solutions, while higher-viscosity grades are used with organic solvents. Examples of film-coating materials that are commercially available include AnyCoat C, Spectracel, Pharmacoat, and the Methocel E Premium LV series. Hypromellose is also used as a suspending and thickening agent in topical formulations. Compared with methylcellulose, hypromellose produces aqueous solutions of greater clarity, with fewer undissolved fibers present, and is therefore preferred in formulations for ophthalmic use. Hypromellose at concentrations between 0.45–1.0% w/w may be added as a thickening agent to vehicles for eye drops and artificial tear solutions. It is also used commercially in liquid nasal formulations at a concentration of 0.1%. Hypromellose is used as an emulsifier, suspending agent, and stabilizing agent in topical gels and ointments. As a protective colloid, it can prevent droplets and particles from coalescing or agglomerating, thus inhibiting the formation of sediments. In addition, hypromellose is used in the manufacture of capsules, as an adhesive in plastic bandages, and as a wetting agent for hard contact lenses. It is also widely used in cosmetics and food products.
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(20) LD50 (rat, IP): 5.2 g/kg
storage
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°C, 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.
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.
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe. Included in the FDA Inactive Ingredients Database (ophthalmic and nasal preparations; oral capsules, suspensions, syrups, and tablets;topical and vaginal preparations). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
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