Microcrystalline cellulose

Microcrystalline cellulose and carboxymethylcellulose sodium occurs as a white or off-white odorless and tasteless hygroscopic powder containing 5–22% sodium carboxymethylcellulose. It is a water-dispersible organic hydrocolloid.

Microcrystalline cellulose is a purified, partially depolymerized cellulose that occurs as a white, odorless, tasteless, crystalline powder composed of porous particles. It is commercially available in different particle sizes and moisture grades that have different properties and applications.

A natural carbohydrate high polymer (polysaccha- ride) consisting of anhydroglucose units joined by an oxygen linkage to form long molecular chains that are essentially linear. It can be hydrolyzed to glucose. The degree of polymerization is from 1000 for wood pulp to 3500 for cotton fiber, giving a molecular weight from 160,000 to 560,000. Cellulose is a colorless solid, d approximately 1.50, insoluble in water and organic solvents. It will swell in sodium hydroxide solution and is soluble in Schweitzer’s reagent. It is the fundamental con- stituent of all vegetable tissues (wood, grass, cotton, etc.) and the most abundant organic material in the world. Cotton fibers are almost pure cellulose; wood contains approximately 50%. The physical structure of cellulose is unusual in that it is not a single crystal but consists of crystalline areas embedded in amorphous areas. Chemical reagents penetrate the latter more easily than the former. Cel- lulose is virtually odorless and tasteless and is com- bustible, with an ignition point of approximately 450F. In some forms, it is flammable. For example, railroad shipping regulations require a flammable label on such items as burnt fiber, burnt cotton, wet waste paper, and wet textiles. Fires have been known to occur in warehouses in which telephone books were stored. These were undoubtedly due to heat buildup in the paper caused by microbial activity and self-sustaining oxidation.

Odorless, white powdery fibers. Density 1.5 g cm-3. The biopolymer composing the cell wall of vegetable tissues. Prepared by treating cotton with an organic solvent to de-wax Cellulose microcrystalline and removing pectic acids by extration with a solution of sodium hydroxide. The principal fiber composing the cell wall of vegetable tissues (wood, cotton, flax, grass, etc.). Technical uses depend on the strength and flexibility of its fibers. Insoluble in water. Soluble with chemical degradation in sulfuric aicd, and in concentrated solutions of zinc chloride. Soluble in aqueous solutions of cupric ammonium hydroxide (Cu(NH3)4(OH)2).

A nuisance dust. When heated to decomposition it emits acrid smoke and irritating fumes.

High purity cellulose powders for partition chromatography.

ACCEL-101 is most widely used for direct compression tableting and wet granulation. ACCEL-102 has similar compression properties to ACCEL-101. However, it has larger particle size and therefore, may be of value in improving the flow if fine powders. ACCEL

cellulose is a thickener and an emulsifier. It is obtained from plants. cellulose (microcrystalline) is used as an emulsifier in cosmetic creams. It is the chief constituent of plant fiber.

Wood contains 50–70% cellulose; cotton and other textile fibers of plant origin contain 65–95%; rayon is prepared by dissolving natural cellulose and then precipitating it from solution, with some loss of crystallinity. Cellulose is made into cellophane film and is used to form fibers, resins, coatings and gums.

Cellulose is a carbohydrate polymer made up of glucose units. It consists of fibrous particles and is used as a fiber source and bulking agent in low-calorie formulations.

Microcrystalline cellulose and carboxymethylcellulose sodium is a spray- or bulk-dried blend of microcrystalline cellulose and sodium carboxymethylcellulose. It is prepared by the chemical depolymerization of highly purified wood pulp. The original crystalline areas of the pulp fibers are combined with sodium carboxymethylcellulose, which serves as a protective colloid and also facilitates dispersion of the product; it is then either spray- or bulk-dried.

Microcrystalline cellulose is manufactured by controlled hydrolysis with dilute mineral acid solutions of α-cellulose, obtained as a pulp from fibrous plant materials. Following hydrolysis, the hydrocellulose is purified by filtration and the aqueous slurry is spraydried to form dry, porous particles of a broad size distribution.