This article needs additional citations for verification .(July 2009) |
Names | |
---|---|
Other names Cellulose, methyl ether; methylated cellulose; methylcellulose; E461 | |
Identifiers | |
ChemSpider |
|
ECHA InfoCard | 100.115.188 |
E number | E461 (thickeners, ...) |
UNII | |
CompTox Dashboard (EPA) | |
Properties | |
variable | |
Molar mass | variable |
Pharmacology | |
A06AC06 ( WHO ) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Methyl cellulose (or methylcellulose) is a compound derived from cellulose. It is sold under a variety of trade names and is used as a thickener and emulsifier in various food and cosmetic products, and also as a bulk-forming laxative. Like cellulose, it is not digestible, non-toxic, and not an allergen. In addition to culinary uses, it is used in arts and crafts such as papier-mâché and is often the main ingredient of wallpaper paste.
In 2020, it was the 422nd most commonly prescribed medication in the United States, with more than 100,000 prescriptions. [1]
Methyl cellulose has a wide range of uses.
Methyl cellulose is used to treat constipation and is classified as a bulk forming laxative. [2] It works by increasing the amount of stool present which improves intestinal contractions. [2] [3] Effects generally occur within three days. [2] It is taken orally with sufficient water. [3] Side effects may include abdominal pain. [3]
It is available over the counter. [2] It is sold under the brand name Citrucel among others. [2]
The lubricating property of methylcellulose is of particular benefit in the treatment of dry eyes. [4] Solutions containing methyl cellulose or similar cellulose derivatives are used as substitute for tears or saliva if the natural production of these fluids is disturbed.[ citation needed ]
Methyl cellulose is used in the manufacture of drug capsules; its edible and nontoxic properties provide a vegetarian alternative to the use of gelatin.[ citation needed ]
Methyl cellulose is occasionally added to hair shampoos, tooth pastes and liquid soaps, to generate their characteristic thick consistency. This is also done for foods, for example ice cream [5] or croquette. Methyl cellulose is also an important emulsifier, preventing the separation of two mixed liquids because it is an emulsion stabilizer.[ citation needed ]
The E number of methyl cellulose as food additive is E461. E464 is hydroxypropyl methylcellulose [6] and more soluble in water. [7]
Methyl cellulose, as a gel, has the unique property of setting when hot and melting when cold. [8]
In some meat analogues that are intended to replicate the texture of meat, methyl cellulose is used as an ingredient, typically in concentrations less than 2%. [9] [10]
Methyl cellulose may be used in personal lubricant.[ citation needed ]
Methyl cellulose finds a major application as a performance additive in construction materials. It is added to mortar dry mixes to improve the mortar's properties such as workability, open and adjustment time, water retention, viscosity, adhesion to surfaces etc. Construction grade methyl cellulose is not to be identified with food and pharmaceutical grade methyl cellulose and hydroxypropyl methyl cellulose, as it may be cross-linked with glyoxal for easy dispersion in water.[ citation needed ]
The construction materials can be cement-based or gypsum-based. Notable examples of dry mixture mortars which utilize methyl cellulose include tile adhesives, EIFS, insulating plasters, hand-trowelled and machine-sprayed plaster, stucco, self-leveling flooring, extruded cement panels, skim coats, joint & crack fillers, and tile grouts. Typical usage is about 0.2% – 0.5% of total dry powder weight for dry mixtures.[ citation needed ]
Derivatives of methyl cellulose which improve performance characteristics include hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC). These derivatives typically improve the characteristics such as water retention, vertical surface slip resistance, open time, etc.[ citation needed ]
Methyl cellulose can be employed as a mild glue which can be washed away with water. This may be used in the fixing of delicate pieces of art as well as in book conservation to loosen and clean off old glue from spines and bookboards.[ citation needed ]
Methyl cellulose is the main ingredient in many wallpaper pastes. It is also used as a binder in pastel crayons and also as a binder in medications. Hydroxypropyl methylcellulose (HPMC) is an FDA-approved water-soluble adhesive, has been used in various wet-adhesion applications in construction products, paints, and drug delivery for 70 years. HPMC adheres strongly to all wet surfaces, regardless of hydrophobicity. [11]
Methyl cellulose is used as a rheological modifier in paint to prevent 'sagging'.[ citation needed ]
Methyl cellulose is used as sizing in the production of papers and textiles as it protects the fibers from absorbing water or oil. When applied to several pieces of paper, methyl cellulose will bind the layers together, often to create a more durable or multicolored sheet. In addition, origami artists use it to coat their origami models, as the compound will stiffen and protect the paper against time.[ citation needed ]
Hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC) are used as binders in dust control technologies. They mitigate fugitive dust released in arid and semi-arid areas as well as improve commercial face masks when used in the filtering material. [12]
Methyl cellulose is also used in cell culture to study viral replication. It is dissolved in the same nutrient-containing medium in which cells are normally grown. A single layer of cells is grown on a flat surface, then infected with a virus for a short time. The strength of the viral sample used will determine how many cells get infected during this time. The thick methyl cellulose medium is then added on top of the cells in place of normal liquid medium. As the viruses replicate in the infected cells, they are able to spread between cells whose membranes touch each other, but are trapped when they enter the methyl cellulose. Only cells closely neighboring an infected cell will become infected and die. This leaves small regions of dead cells called plaques in a larger background of living uninfected cells. The number of plaques formed is determined by the strength of the original sample.[ citation needed ]
Aqueous methyl cellulose solutions have been used to slow bacterial and protozoal cell motility for closer inspection. Changing the amount of methyl cellulose in solution permits the adjustment of the solution's viscosity.[ citation needed ]
Methyl cellulose is used in the most common approaches to quantify multiple or single lineage-committed hematopoietic progenitors, called colony-forming cells (CFCs) or colony-forming units (CFUs), in combination with culture supplements that promote their proliferation and differentiation, and allow the clonal progeny of a single progenitor cell to stay together and thus form a colony of more mature cells.[ citation needed ]
It is a hydrophilic white powder in pure form and dissolves in cold (but not in hot) water, forming a clear viscous solution or gel.[ citation needed ]
Methyl cellulose is used as a buffer additive in capillary electrophoresis to control electroosmotic flow for improved separations.[ citation needed ]
The slimy, gooey appearance of an appropriate preparation of methyl cellulose with water, in addition to its nontoxic, nonallergenic, and edible properties, makes it popular for use in special effects for motion pictures and television wherever vile slimes must be simulated. In the film Ghostbusters, the gooey substance the supernatural entities used to "slime" the Ghostbusters was mostly a thick water solution of methyl cellulose. [13] The Aliens ooze and drip a great deal of methyl cellulose—especially the queen. [14]
Methyl cellulose has been used to safely simulate molten materials, as well. In several of the Terminator films, it was back-lit with colored gels and films to reproduce the heated glow of iron in the large pouring ladles used to transport the metal from the smelting ovens to the various molds and forms.[ citation needed ] Methyl cellulose was also a stand-in for the lava flows in Los Angeles in Volcano and on the volcanic surface of Mustafar, in Star Wars: Episode III – Revenge of the Sith .[ citation needed ]
Methyl cellulose does not occur naturally and is synthetically produced by heating cellulose with caustic solution (e.g. a solution of sodium hydroxide) and treating it with methyl chloride. In the substitution reaction that follows, the hydroxyl residues (-OH functional groups) are replaced by methoxide (-OCH3 groups).[ citation needed ]
Different kinds of methyl cellulose can be prepared depending on the number of hydroxyl groups substituted. Cellulose is a polymer consisting of numerous linked glucose molecules, each of which exposes three hydroxyl groups. The Degree of Substitution (DS) of a given form of methyl cellulose is defined as the average number of substituted hydroxyl groups per glucose. The theoretical maximum is thus a DS of 3.0, however more typical values are 1.3–2.6.[ citation needed ]
Different methyl cellulose preparations can also differ in the average length of their polymer backbones.[ citation needed ]
Methyl cellulose has a lower critical solution temperature (LCST) between 40 °C and 50 °C.[ citation needed ] At temperatures below the LCST, it is readily soluble in water; above the LCST, it is not soluble, which has a paradoxical effect that heating a saturated solution of methyl cellulose will turn it solid, because methyl cellulose will precipitate out. The temperature at which this occurs depends on DS-value, with higher DS-values giving lower solubility and lower precipitation temperatures because the polar hydroxyl groups are masked.[ citation needed ]
Preparing a solution of methyl cellulose with cold water is difficult however: as the powder comes into contact with water, a gel layer forms around it, dramatically slowing the diffusion of water into the powder; hence, the inside remains dry. A better way is to first mix the powder with hot water, so that the methyl cellulose particles are well dispersed (and so have a much higher effective surface area) in the water, and cool down this dispersion while stirring, leading to the much more rapid dissolution of those particles. [15]
Cellulose is an organic compound with the formula (C
6H
10O
5)
n, a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose content of cotton fiber is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%.
Guar gum, also called guaran, is a galactomannan polysaccharide extracted from guar beans that has thickening and stabilizing properties useful in food, feed, and industrial applications. The guar seeds are mechanically dehusked, hydrated, milled and screened according to application. It is typically produced as a free-flowing, off-white powder.
A tablet is a pharmaceutical oral dosage form or solid unit dosage form. Tablets may be defined as the solid unit dosage form of medication with suitable excipients. It comprises a mixture of active substances and excipients, usually in powder form, that are pressed or compacted into a solid dose. The main advantages of tablets are that they ensure a consistent dose of medicine that is easy to consume.
Pectin is a heteropolysaccharide, a structural acid contained in the primary lamella, in the middle lamella, and in the cell walls of terrestrial plants. The principal chemical component of pectin is galacturonic acid which was isolated and described by Henri Braconnot in 1825. Commercially produced pectin is a white-to-light-brown powder, produced from citrus fruits for use as an edible gelling agent, especially in jams and jellies, dessert fillings, medications, and sweets; and as a food stabiliser in fruit juices and milk drinks, and as a source of dietary fiber.
K-Y Jelly is a water-based, water-soluble personal lubricant, most commonly used as a lubricant for sexual intercourse and masturbation. A variety of different products and formulas are produced under the K-Y banner, some of which are not water-soluble.
Sodium silicate is a generic name for chemical compounds with the formula Na
2xSi
yO
2y+x or (Na
2O)
x·(SiO
2)
y, such as sodium metasilicate Na
2SiO
3, sodium orthosilicate Na
4SiO
4, and sodium pyrosilicate Na
6Si
2O
7. The anions are often polymeric. These compounds are generally colorless transparent solids or white powders, and soluble in water in various amounts.
In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of cigarette filters and playing cards. In photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce.
Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch and glycogen. Dextrins are mixtures of polymers of D-glucose units linked by α-(1→4) or α-(1→6) glycosidic bonds.
Excipient is a substance formulated alongside the active ingredient of a medication. Excipients serve various purposes, including long-term stabilization, bulking up solid formulations containing potent active ingredients in small amounts, or enhancing the therapeutic properties of the active ingredient in the final dosage form. They can facilitate drug absorption, reduce viscosity, or enhance solubility. Excipients can also aid in the manufacturing process by improving the handling of active substances, facilitating powder flowability, or preventing denaturation and aggregation during the expected shelf life. The selection of excipients depends on factors such as the route of administration, dosage form, and active ingredient.
Hydroxypropyl cellulose (HPC) is a derivative of cellulose with both water solubility and organic solubility. It is used as an excipient, and topical ophthalmic protectant and lubricant.
A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their taste; thickeners are also used in paints, inks, explosives, and cosmetics.
Carboxymethyl cellulose (CMC) or cellulose gum is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used in its sodium salt form, sodium carboxymethyl cellulose. It used to be marketed under the name Tylose, a registered trademark of SE Tylose.
In the manufacture of pharmaceuticals, encapsulation refers to a range of dosage forms—techniques used to enclose medicines—in a relatively stable shell known as a capsule, allowing them to, for example, be taken orally or be used as suppositories. The two main types of capsules are:
Hypromellose (INN), short for hydroxypropyl methylcellulose (HPMC), is a semisynthetic, inert, viscoelastic polymer used in eye drops, as well as an excipient and controlled-delivery component in oral medicaments, found in a variety of commercial products.
Poly(2-hydroxyethyl methacrylate) (pHEMA) is a polymer that forms a hydrogel in water. Poly (PHEMA) hydrogel for intraocular lens (IOL) materials was synthesized by solution polymerization using 2-hydroxyethyl methacrylate (HEMA) as raw material, ammonium persulfate and sodium pyrosulfite (APS/SMBS) as catalyst, and triethyleneglycol dimethacrylate (TEGDMA) as cross-linking additive. It was invented by Drahoslav Lim and Otto Wichterle for biological use. Together they succeeded in preparing a cross-linking gel which absorbed up to 40% of water, exhibited suitable mechanical properties and was transparent. They patented this material in 1953.
Ethyl cellulose is a derivative of cellulose in which some of the hydroxyl groups on the repeating glucose units are converted into ethyl ether groups. The number of ethyl groups can vary depending on the manufacturer.
Hydroxyethyl cellulose is a gelling and thickening agent derived from cellulose. It is widely used in cosmetics, cleaning solutions, and other household products. Hydroxyethyl cellulose and methyl cellulose are frequently used with hydrophobic drugs in capsule formulations, to improve the drugs' dissolution in the gastrointestinal fluids. This process is known as hydrophilization.
Hydrophilization is a process used for hydrophobic drugs to increase their release rate from capsules, which is dependent on the rate of dissolution, by covering the surface of the drug particles with minute droplets of a hydrophilic polymer solution.
Paper chemicals designate a group of chemicals that are used for paper manufacturing, or modify the properties of paper. These chemicals can be used to alter the paper in many ways, including changing its color and brightness, or by increasing its strength and resistance to water. The chemicals can be defined on basis of their usage in the process.
In reality , the gooey substance was derived from methylcellulose ether — a powdered thickening agent used in pharmaceuticals and food products0
If you've seen someone get slimed in Ghostbusters, or the drooling creature in one of the Alien films, you've seen methylcellulose in action.