Methylcellulose

Methylcellulose is a non-ionic cellulose ether, which is made by introducing methyl groups into cellulose by etherification.Methylcellulose has four important functions: thickening, surface activity, film-forming, and hot gel formation (melting on cooling).Methylcellulose solution is stable over a wide pH range (3.0~11.0), and has unique thermal gelling properties, that is, it forms a gel when heated and melts when cooled. The gelling temperature range is 50~70 ℃.

MC is almost insoluble in anhydrous ethanol, ethyl ether and acetone.It quickly disperses and swells in hot water of 80 ~ 90℃, and dissolves quickly after cooling. The aqueous solution is quite stable at room temperature, and can gel at high temperature, and the gel can change with the temperature of the solution.It has excellent wettability, dispersability, adhesion, thickening, emulsification, water retention and film formation, as well as the impermeability of oil.The film has excellent toughness, flexibility and transparency. Because it is non-ionic type, it can be compatible with other emulsifiers, but it is easy to salt-out, and the solution is stable in the range of pH2-12.Apparent density: 0.30-0.70g/cm3, density is about 1.3g/cm3.

The theoretical degree of substitution of methyl cellulose in industry is 1.5~2.0, and the loose density is 0.35 ~ 0.55g/cm3.

The appearance of gray-white fibrous to powdery rice gel temperature (2% aqueous solution) 50 ~ 55℃, methoxy content of 26% ~ 33%, water insoluble substance ≤2.0%,

Substitution degree (DS) 1.3 ~ 2.0

Moisture 5.0% or less

Viscosity (20℃, 2% aqueous solution) 15 ~ 4000MPa ·s

Modified Cellulose;MODIFIED CELLULOSE,

CAS no. : 9004-67-5

EINECS no. : 232-674-9

Quality indicators

Appearance grayish white fibrous to powdery rice shape

Gel temperature (2% aqueous solution) 50 ~ 55℃

Methoxy content of 26% ~ 33%

Water insoluble substance ≤2.0%

Substitution degree (DS) 1.3 ~ 2.0

Moisture 5.0% or less

Viscosity (20℃, 2% aqueous solution) 15 ~ 4000MPa ·s

application

Used as a thickener for water-soluble adhesives, such as neoprene latex.

It can also be used as dispersant, emulsifier and stabilizer for suspension polymerization of vinyl chloride and styrene.MC at dS =2.4 ~ 2.7 is soluble in polar organic solvent, which can prevent the volatilization of solvent (dichloromethane - ethanol mixture).

Used as a thickener for water-soluble adhesives, such as neoprene latex.

It can also be used as dispersant, emulsifier and stabilizer for suspension polymerization of vinyl chloride and styrene.MC at dS =2.4 ~ 2.7 is soluble in polar organic solvent, which can prevent the volatilization of solvent (dichloromethane - ethanol mixture).

To identify

(1) Take an appropriate amount of 1% aqueous solution of the product, place it in a test tube, slowly add 2ml 0.035% sulfuric acid solution of anthrone along the wall of the tube, place it, and show blue-green ring at the interface between the two liquid.

(2) Take 10ml 1% aqueous solution of the product, heat it, the solution produces fog or flake precipitation, after cooling, the precipitation is dissolved.

(3) take the product 1% of the aqueous solution right amount, poured on the glass plate, after the evaporation of water, the formation of a layer of toughness of the film.

check

Take the goods 1.0 g pH, add water 100 ml dissolves, determination (appendix Ⅵ H) in accordance with the law, the pH value should be 4.0 ~ 8.0.

The viscosity of the product is calculated as a dry product, adding water at 90℃ to make 2.0%(g/g) solution, and stirring thoroughly for about 10 minutes.Cooling in an ice bath and continue to stir in the process of cooling, maintain 40 minutes again, adjust the weight, stir well, at 20 ℃ + / - 0.1 ℃, with a rotary viscosimeter measurement (appendix Ⅵ G the second law), marked viscosity is equal to or less than 100 mpa. S, viscosity should be marked viscosity of 80.0% ~ 120.0%, marked viscosity is greater than 100 mpa. S, viscosity should be 75.0% ~ 140.0% of viscosity.

Dry weight loss Pick up the goods, 2 hours at 105 ℃ drying, loss of weight reduction shall not be over 5.0% (appendix Ⅷ L).On ignition residue Take the goods of 1.0 g, check (appendix Ⅷ N) in accordance with the law.Residue shall not exceed 1.0%.

Take on ignition of heavy metal residue under a legacy of the residue, check the second method (appendix Ⅷ H) in accordance with the law, containing heavy metals shall not be twenty over one million.

Take the goods 1.0 g of salt, arsenic and calcium hydroxide 1.0 g, mix and stir well of water, after drying, use small fire burning carbonization, first in 500 ~ 600 ℃ on ignition completely ashing, put the cold, 23 ml and add 8 ml of hydrochloric acid and water in accordance with the inspection method (appendix Ⅷ J first), should comply with the regulation (0.0002%).

Content determination to take the goods, precision said, according to methoxyl assay (appendix Ⅶ G), a quick.

Dissolution method

MC >;When the product is added directly to the water, it coagulates and then dissolves, but the dissolution is slow and difficult.The following three dissolution methods are recommended. Users can choose the most convenient method according to the use situation:

1. Hot water method: since MC is not dissolved in hot water, it can be uniformly dispersed in hot water at the initial stage. When cooling down, two typical methods are described as follows:

1). Put the required amount of hot water in the container and heat it to about 70℃.After slowly stirring, MC is gradually added. MC floats on the surface of water at first, and then a slurry is gradually formed. The slurry is cooled under stirring.

2). Add 1/3 or 2/3 of the required amount of water into the container, and heat it to 70℃, disperse MC according to the method of 1) to prepare hot water slurry;The remaining amount of cold or ice water is then added to the hot slurry, stirring and cooling the mixture.

2. Powder Mixing Method: MC powder particles and other powdery ingredients with equal or greater quantities are fully dispersed by dry mixing, and then dissolved in water. At this time, MC can be dissolved without condensation.

3. Wetting method with organic solvent: MC is pre-dispersed or wetting with organic solvent, such as ethanol, ethylene glycol or oil, and then dissolved with water. At this time, MC can also be dissolved smoothly.

Functions and applications:

Coating material;Emulsifier;Suspended aid;Disintegrating agents for tablets and capsules;An adhesive for tablets;Reinforced adhesion agent.Methylcellulose is widely used in oral and topical preparations, as shown in the table below

Administration route:

Oral administration, injection (joint injection, intramuscular injection, intrasynovial injection), sublingual, buccal, ocular, nasal, soft tissue, local, percutaneous, dental

Security:

Methylcellulose is widely used in a variety of oral and topical preparations, as well as in cosmetics and foods.It is generally considered non-toxic, non-allergenic and non-irritating.When taken orally, methylcellulose cannot be digested or absorbed and is therefore a non-caloric material. Intake of methylcellulose cables by fireflies may temporarily increase flatulence and gastrointestinal distension.In ordinary individuals, a large amount of oral methylcellulose has a laxative effect, so medium and high viscosity cellulose can be used as a compatibilizing and laxative agent.If the amount of fluid that accompanies the ingestion of methylcellulose is insufficient, it can lead to obstruction of the esophagus.

In addition, high intake of methyl and cellulose may interfere with the absorption of some minerals. However, these adverse effects and some possible adverse effects are primarily related to methyl cellulose as a laxative, and these side effects are no longer a major factor when it is used as an oral excipherant.Although methylcellulose has been used in intraarticular and intramuscular injections, it is not normally used in intravenous products.In vivo studies of rats have shown that intravenous methylcellulose may cause glomerulonephritis and hypertension.

The WHO has not yet set a daily allowance for this product because its use in food is not considered hazardous to health.LD50(Mouse, IP):275g/kg[1] LDLO (Mouse, IV): 1 g/kg[6]

Incompatibility taboo:

Methylcellulose and aminoacridine hydrochloride, chlorocresol, mercury dichloride, phenol, resorcinol, tannic acid, silver nitrate.Incompatibility contraindication of cipyrloammonium, p-hydroxybenzoic acid, p-aminobenzoic acid, methyl hydroxybenzoate, propyl hydroxybenzoate and butyl hydroxybenzoate were found.Inorganic acids (especially polyacid > salt, phenol and tannic acid) can coagulate the methyl cellulose solution, but the addition of ethanol (95%) or ethylene glycol diacetic acid can prevent this process from occurring.Methylcellulose can be complexed with highly surface active compounds such as tetracaine and dibutoline sulfate.High concentration of electrolyte solution can increase the viscosity of methyl cellulose adhesive, due to the precipitation of methyl cellulose, when methyl cellulose reaches very high concentration, it will be completely precipitated in the form of separate or continuous gel.

Usual and maximum dosage:

Oral maximum dosage: 183.60MG;Buccal/sublingual maximum dosage: 4.00MG;Maximum amount of intra-articular injection: 0.10%;Maximum dosage of intramuscular injection: 0.10%;Maximum dosage for eye: 0.50%;Maximum dosage for local use: 1.50% [7]

Oral maximum dosage: 607.5mg;Maximum percutaneous dosage: 150mg;Maximum dosage of general external agent: 70mg/g;Sublingual maximum dosage: 8mg;Maximum dosage for eye use: 5mg/g;Dental and oral use maximum 160mg;Maximum dosage for other external use: 0.353mg

Source and system:

This product is made by alkalizing wood pulp fiber and then alkalizing cellulose with methylation of methyl chloride.Finally, the product is purified and ground to a powder.

Management Situation:

It is listed in GRAS.It is licensed as a food additive in Europe.Has been included in FDA's inactive component guidelines (for sublingual tablets, intramuscular injections, ophthalmic preparations, oral capsules, oral suspensions and oral tablets, topical or vaginal preparations).Licensed in the United Kingdom for use in non-injectable preparations.