What is HPMC?

HPMC Hydroxypropyl methylcellulose, also known as hypromellose, is one of the non-ionic cellulose mixed ethers. It is a semi-synthetic, inactive, viscoelastic polymer commonly used as a lubricant in ophthalmology, or as an excipient or excipient in oral medicines.

Product name Hydroxypropyl methyl cellulose(HPMC)
Other name Hydroxypropyl methylcellulose,MHPC, methyl Hydroxypropyl cellulose
CAS Registration Number 9004-65-3
Appearance white fibrous or granular powder
safety description S24/25

The physical and chemical properties
Appearance: white or almost white fibrous or granular powder
Stability: Solids are flammable and incompatible with strong oxidants.
Granularity; The pass rate of 100 mesh was more than 98.5%. The pass rate of 80 eyes is 100%. Special size of particle size 40 ~ 60 mesh.
Carbonization temperature: 280-300℃
Apparent density: 0.25-0.70g/cm3 (usually around 0.5g/cm3), specific gravity 1.26-1.31.
Color changing temperature: 190-200℃
Surface tension: 42-56dyne/cm in 2% aqueous solution
Solubility: soluble in water and some solvents, such as appropriate proportion of ethanol/water, propanol/water, etc. Aqueous solution has surface activity. High transparency, stable performance, different specifications of the product gel temperature is different, solubility changes with the viscosity, the lower the viscosity, the greater the solubility, different specifications of HPMC performance has a certain difference, HPMC solution in water is not affected by pH value.
The surface activity of HPMC decreased with the decrease of methoxyl content, the increase of gel point and the decrease of water solubility.
HPMC also has thickening ability, salt resistance low ash powder, pH stability, water retention, dimensional stability, excellent film forming, as well as a wide range of resistance to enzyme, dispersity and bonding characteristics.

Production methods
The refined cotton cellulose is treated with lye at 35-40℃ for half an hour, pressed, the cellulose is crushed and aged at 35℃, so that the average polymerization degree of the alkali fiber obtained is within the required range. Put the alkali fiber into the etherification kettle, add propylene oxide and methane chloride successively, etherize at 50-80℃ for 5h, the highest pressure is about 1.8mpa. Then add proper amount of hydrochloric acid and oxalic acid washing materials in 90℃ hot water to enlarge the volume. When the water content in the material is less than 60%, it is dried to less than 5% by hot air flow at 130℃. Finally, the finished product is crushed and screened through 20 mesh.

Dissolution method
1, all models can be added to the material by dry mixing method.
2, need to be directly added to normal temperature water solution, it is best to use cold water dispersion, after adding generally in 10-90 minutes to thicken.
3. Ordinary models can be dissolved after mixing and dispersing with hot water and adding cold water after stirring and cooling.
4. When dissolving, if the phenomenon of agglomerating occurs, it is because the mixing is not sufficient or ordinary models are directly added to the cold water. At this time, it should be stirred quickly.
5. If bubbles occur during dissolution, they can be removed by standing for 2-12 hours (the specific time depends on the consistency of the solution) or by vacuumizing and pressurizing, or by adding an appropriate amount of defoaming agent.

HPMC uses
Used as thickener, dispersant, binder, exciphant, oil resistant coating, filler, emulsifier and stabilizer in textile industry. Also widely used in synthetic resin, petrochemical, ceramic, paper, leather, medicine, food and cosmetics and other industries.

The main purpose
1, construction industry: as cement mortar water retention agent, retarder mortar with pumping. In plastering, gypsum, putty powder or other building materials as adhesive, improve daub and prolong the operation time. Used for pasting ceramic tile, marble, plastic decoration, paste strengthen agent, still can reduce cement dosage. HPMC’s water retention performance makes the slurry after application will not be due to dry too fast and crack, enhance the strength after hardening.
2, ceramic manufacturing: widely used as adhesive in ceramic product manufacturing.
3, coating industry: in the coating industry as a thickener, dispersant and stabilizer, in water or organic solvents have a good solubility. As a paint remover.
4, ink printing: in the ink industry as a thickener, dispersant and stabilizer, in water or organic solvents have a good solubility.
5, plastic: for forming release agent, softener, lubricant, etc.
6, PVC: PVC production as a dispersant, suspension polymerization preparation of PVC main auxiliaries.
7, pharmaceutical industry: coating materials; Membrane material; Rate-controlled polymer materials for sustained-release preparations; Stabilizing agent; Suspended aid; Tablet adhesive; Increases the goo
8, Others: also widely used in leather, paper products industry, fruit and vegetable preservation and textile industry.

Specific industry application

Construction industry
1, cement mortar: improve the dispersion of cement – sand, greatly improve the plasticity and water retention of mortar, to prevent cracks have the effect, can enhance the strength of cement.

2, ceramic tile cement: improve the plasticity of ceramic tile mortar, water retention, improve the glue relay of ceramic tile, prevent powder.
3, asbestos and other refractory coating: as a suspension agent, liquidity improvement agent, but also improve the base of the glue relay.
4, gypsum slurry: improve water retention and processability, improve the adhesion of the base.
5, joint cement: add in gypsum board with joint cement, improve fluidity and water retention.
6, latex putty: improve the fluidity and water retention of resin latex based putty.
7, mortar: as a substitute for natural paste, can improve water retention, improve the glue relay with the base.
8, coating: as a plasticizer of latex coating, it has a role in improving the operating performance and fluidity of coating and putty powder.
9, spraying coating: to prevent cement or latex spraying only material filler sinking and improve the flow and spray beam graphics have good effect.
10, cement, gypsum secondary products: as cement – asbestos and other hydraulic materials pressing molding binder, improve the fluidity, can get uniform molding products.
11, fiber wall: because of the anti-enzyme anti-bacterial effect, as the binder of sand wall is effective.
12, other: can be used as thin mortar mortar and mortar operator role of the bubble holding agent.

The chemical industry
1, vinyl chloride, vinyl polymerization: as polymerization suspension stabilizer, dispersant, with vinyl alcohol (PVA) hydroxypropyl cellulose (HPC) and can control the distribution of particle shape and particle.
2, adhesive: as wallpaper adhesive, instead of starch can usually be used with vinyl acetate latex coating.
3. Pesticide: added to insecticides and herbicides, it can improve the adhesion effect when spraying.
4, latex: improve asphalt emulsion stabilizer, styrene butadiene rubber (SBR) latex thickener.
5, binder: as a pencil, crayon forming adhesive.

The cosmetics industry
1. Shampoo: improve the viscosity and stability of bubbles of shampoo, detergent and detergent.
2. Toothpaste: Improve the fluidity of toothpaste.

The food industry
1, canned citrus: prevent in preservation due to the decomposition of orange glycosides and whitening metamorphism to achieve freshness.
2, cold fruit products: add in fruit dew, ice medium, make the taste better.
3, sauce: as sauce, tomato sauce emulsifying stabilizer or thickening agent.
4, cold water coating glazing: used for frozen fish storage, can prevent discoloration, quality reduction, with methyl cellulose or hydroxypropyl methyl cellulose solution coated glazing, and then frozen on the ice.
5, the adhesive of pills: as the forming adhesive of pills and pills, the bonding and collapse (quickly dissolve and disperse when taking) is good.

Pharmaceutical industry
1. Coating: the coating agent is made into an organic solvent solution or aqueous solution for tablets, especially for the particles made of spray coating.
2, slow down agent: 2-3 grams per day, each time 1-2G dosage, in 4-5 days to show the effect.
3, eye medicine: because the osmotic pressure of hydroxypropyl methyl cellulose aqueous solution is the same as tears, so it is small to the eyes, add eye medicine, as a lubricant to contact the eyeball lens.
4, gelatinous agent: as the base material of gelatinous external medicine or ointment.
5, impregnating drug: as a thickening agent, water retention agent.

Furnace industry
1, electronic materials: as ceramic electric denser, bauxite ferrite magnetic pressure molding adhesive, can be used with 1.2-propylene glycol.
2, glaze: used as ceramic glaze and porcelain with enamel, can improve bonding and processability.
3, refractory mortar: add in refractory mortar or cast furnace material, can improve the plasticity and water retention.

Other industries
1, fiber: as printing dye paste for pigments, boron forest dyes, salt based dyes, textile dyes, in addition, in the kapok ripple processing, can be used with the heat hardening resin.
2, paper: used for carbon paper leather gluing and oil processing and other aspects.
3, leather: as the final lubrication or disposable adhesive use.
4, water-based ink: added to water-based ink, ink, as thickening agent, film forming agent.
5, tobacco: as the adhesive of recycled tobacco.

Pharmacopoeia standard

Source and content
This product is 2- hydroxypropyl ether methyl cellulose. Hydroxypropyl methylcellulose can be divided into four types according to the content of methoxy and hydroxypropyl, namely 1828, 2208, 2906, 2910. The content of each substituted methoxy (-OCH3) and hydroxypropoxy (-OCH2ChohCH3) should comply with the provisions of the attached table.

character
This product is white or quasi-white fibrous or granular powder; Odourless.
This product is almost insoluble in anhydrous ethanol, ether and acetone; Swelling in cold water to form a clear or slightly turbid colloid solution.

To identify
(1) Take 1g of the product, heat 100mL of water (80 ~ 90℃), stir continuously, cool in an ice bath, and form a sticky liquid; Put 2mL of the solution into a test tube, slowly add 1mL of 0.035% anthracene sulfuric acid solution along the tube wall, place it for 5 minutes, and a blue-green ring appears at the interface between the two liquids.
(2) Appropriate amount of the viscous liquid under identification (1) is poured onto the glass plate. After evaporation of water, a layer of tough film is formed.

check
1, ph
After cooling, adjust the solution to 100g with water and stir until it is completely dissolved. Determine according to law (Appendix ⅵ H, Part II of Pharmacopoeia, 2010 edition). PH value should be 5.0-8.0.
2, viscosity
2.0% (g/g) suspension was prepared by taking 10.0g of the product and adding 90℃ water to make the total weight of the sample and water 500.0g as the dry product. The suspension was fully stirred for about 10 minutes until the particles were completely evenly dispersed and wetted. The suspension was cooled in an ice bath and continued to stir for 40 minutes during the cooling process. A single cylinder rotary viscosimeter (ndJ-1 can be used for samples with a viscosity less than 100Pa·s, and NDJ-8S can be used for samples with a viscosity greater than or equal to 100Pa·s, or other suitable qualified viscosimeter) was used at 20℃±0.1℃, determined in accordance with the law (the second method of ⅵ G in appendix II of Pharmacopoeia 2010 edition). If the labeled viscosity is less than 600mPa·s, the viscosity should be 80% ~ 120% of the labeled viscosity; If the labeled viscosity is greater than or equal to 600mPa·s, the viscosity should be 75% to 140% of the labeled viscosity.

3 Insoluble matter in water
Take 1.0g of the product, put it into a beaker, add 100mL hot water at 80-90 ℃, swell for about 15 minutes, cool it in an ice bath, add 300mL water (if necessary, increase the volume of water appropriately to ensure that the solution is filtered), and stir it fully, filter it through a no. 1 vertical melting glass crucible that has been dried to constant weight at 105℃, and clean the beaker with water. The liquid was filtered into the above vertical melting glass crucible and dried to constant weight at 105℃, with residual residue not exceeding 5mg (0.5%).

4 Dry weight loss
Take this product and dry it at 105℃ for 2 hours, and the weight loss shall not exceed 5.0% (Appendix ⅷ L, Part II, Pharmacopoeia 2010 edition).

5 Burning residue
Take 1.0g of this product and check it according to law (Appendix ⅷ N, Part II of pharmacopoeia 2010 edition), and the residual residue shall not exceed 1.5%.

6 heavy metal
Take the residue left under the incandescent residue, check in accordance with the law (the second method of Appendix ⅷ H of the second part of the 2010 edition of pharmacopoeia), containing heavy metals shall not exceed 20 parts per million.

7 arsenic salt
Take 1.0g of this product, add 1.0g calcium hydroxide, mix, add water to stir evenly, dry, first with a small fire to carbonize, and then at 600℃ to burn completely ash, cooling, add 5mL hydrochloric acid and 23mL water to dissolve, check according to law (2010 edition of pharmacopoeia ii Appendix ⅷ J first method), should comply with the provisions (0.0002%).

Content determination
1,methoxyl
Methoxy, ethoxy and hydroxypropoxy (appendix VII F, Part II, 2010 Edition of Pharmacopoeia) were determined. If the second method (volumetric method) is used, take the product, weigh it accurately and measure it according to law. The measured methoxy amount (%) is deducted from the product of hydroxypropoxy amount (%) and (31/75×0.93).
2, hydroxypropoxy
Methoxy, ethoxy and hydroxypropoxy (appendix VII F, Part II, 2010 Edition of Pharmacopoeia) were determined. If the second method (volume method) is used, take the product about 0.1g, weigh accurately, determine according to law, and obtain.

Pharmacology and toxicology
Hydroxypropyl methyl cellulose is part of cellulose methyl and part of the hydroxypropyl ether, it can be dissolved in cold water to form a viscous solution, its properties and tears in the viscoelastic substances (mainly mucin) close to, therefore, can be used as artificial tears. The mechanism of action is that the polymer adheres to the surface of the eye through adsorption, mimicking the action of conjunctival mucin, thereby improving the state of ocular mucin reduction and increasing the duration of eye retention in the state of tear reduction. This adsorption is independent of the viscosity of the solution and thus allows a lasting wetting effect even for lower viscosity solutions. In addition, corneal wetting is increased by reducing the contact Angle of the clean corneal surface.

pharmacokinetics
No pharmacokinetic data have been reported for topical use of this product.

indications
Moisten the eyes with insufficient tear secretion and eliminate eye discomfort.

Usage
Both adults and children can use it. 1-2 drops, three times a day; Or as prescribed by a doctor.
Adverse reactions edit speech
In rare cases it can cause eye discomfort such as eye pain, blurred vision, persistent conjunctival congestion or eye irritation. If the above symptoms are obvious or persistent, stop using the drug and go to the hospital for examination.
taboo

Contraindicated in persons allergic to this product.

Matters needing attention
1. Do not touch the drop bottle head to eyelid and other surfaces to prevent contamination
2. Please keep the product out of reach of children
3. One month after opening the bottle, it is not suitable to continue to use it.
4. Medication for pregnant and lactating women: no reports of reproductive damage or other problems caused by HYDROXYpropyl cellulose in human body were found; No adverse reactions have been reported in infants during lactation. Therefore, there is no special contraindication for pregnant and lactating women.
5. Medication for children: compared with other age groups, hydroxypropyl methylcellulose in children does not cause more adverse reactions. Therefore, children and adults can use this product according to the same plan.
6, medication for the elderly: the use of hydroxypropyl methylcellulose in elderly patients, compared with other age groups, does not cause different side effects or other problems. Accordingly, medication of senile patient does not have special contraindication.
7, storage: airtight storage.

Safety performance
Health hazard
This product is safe and non-toxic, can be used as food additive, no heat, no irritation to skin and mucous membrane contact. It is generally considered safe (FDA1985). The permissible daily intake is 25mg/kg (FAO/WHO 1985). Protective equipment should be worn during operation.

The environmental impact
Avoid air pollution caused by dust flying.
Physical and chemical hazards: avoid contact with fire sources, and avoid forming a large amount of dust in a closed environment to prevent explosive hazards.
Store items shipped
Pay attention to sun protection from rain and moisture, avoid direct sunlight, sealed in a dry place.
Security term
S24/25: Avoid contact with skin and eyes.
Avoid contact with skin and eyes.