Chemistry name: Carboxymethylcellulose sodium; CMC-Na

CAS No.: 9004-32-4

EINECS No.: 900-432-4

Chemical formula:  [C6H7O2(OH)2OCH2COONa]n

Molecular mass: N/A

Definition:

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EXCfiller®Carboxymethylcellulose sodium is a semi-synthetic anionic polymer formed through etherification reactions, which replace the hydroxyl groups on a cellulose glucose ring backbone with carboxymethyl groups. It readily dissolves in both cold and hot water (20-80 °C), forming transparent, viscous solutions that are free from precipitation. It disperses well in solid beverages and dissolves faster than hydroxypropyl methyl cellulose (HPMC). It performs stably across pH 2-12 and has moderate salt tolerance. It is suitable for use in food, health supplement and pharmaceutical applications, providing thickening, suspension, emulsification, stabilisation, film formation and moisture retention. It significantly improves the smoothness of solid beverages, prevents separation and sedimentation, and serves as a disintegrant and suspension aid in formulations.

■ Source

The production process of EXCfiller®Carboxymethylcellulose sodium involves cellulose, etherifying agents and auxiliary materials. Sources of cellulose include softwood pulp (α-cellulose content ≥98%), hardwood pulp (α-cellulose content ≥95%), cotton linters (α-cellulose content ≥99%, which are prioritised for pharmaceutical-grade products) and bagasse pulp (which requires purification to α-cellulose content ≥97% for food-grade products). The raw materials used for the etherification agent (functional group sources) include sodium chloroacetate and chloroacetic acid. Auxiliary materials include sodium hydroxide, which is used as an alkalising agent for cellulose activation. Solvents include water and ethanol, and neutralising agents include hydrochloric acid for adjusting the pH post-treatment.

Particularities of EXCfiller®Carboxymethylcellulose sodium:

Product Specifications:

EXCfiller®Carboxymethylcellulose sodium is available in the following specification and contents:

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☑ EXCfiller®Carboxymethylcellulose sodium (Viscosity 600-1120 mPa.s)

Product quality standards:

● USP, EP, BP, CP, Food grade, In-house

EXCfiller®Carboxymethylcellulose sodium Applications:

The core applications of EXCfiller®Carboxymethylcellulose sodium utilise its anionic polymer properties, including full-temperature solubility (it is soluble in both cold and hot water) and pH stability. In the pharmaceutical industry, it is used for formulation shaping, dispersion stabilisation and improving medication compliance. In the food industry, it is used for improving texture, stabilising systems, and optimising sensory properties. It complies with mainstream global regulations, is non-allergenic and has a clearly defined sodium content of 6.0-8.5%. It is highly compatible with ingredients such as whey protein, casein, vitamins and minerals, and does not cause flocculation or precipitation reactions. This makes it suitable for industrial production in a variety of scenarios, including solid beverages, dietary supplements and pharmaceutical formulations.

In the pharmaceutical field, applications comply with USP-NF, EP and ChP standards. Tablet excipients account for 55% of the total demand for pharmaceutical-grade EXCfiller®Carboxymethylcellulose sodium. EXCfiller®Carboxymethylcellulose sodium can serve as a disintegrant, promoting the rapid dissolution of tablets in gastrointestinal fluids and enhancing drug release (thus preventing 'slow release' issues). The addition rate is 3%-8% of the total tablet weight. As a binder, it improves granule flowability and compressibility, enhancing tablet hardness and preventing excessive friability, with a solution concentration of 2-5%. When used as a coating solution thickener and stabiliser, it improves film extensibility (preventing cracking of the coating). In capsule excipients, it serves as a flow aid and stabiliser for capsule filling, improving powder flowability and compressibility while preventing stratification and mould adhesion during filling. It also enhances the flexibility of capsule materials and prevents soft capsule brittleness, especially in high-humidity environments.

EXCfiller®Carboxymethylcellulose sodium has many applications in the food industry, primarily in solid beverages and dietary supplements. As a thickening and suspending agent, it prevents functional ingredients such as protein powders, probiotics, calcium-iron-zinc complexes and dietary fibre from separating or settling, thereby maintaining system uniformity. It improves the smoothness of beverages and masks the off-flavours of functional components (e.g. the beany taste of protein powders or the sourness of vitamin C). As an instant dispersant, it improves the dispersibility and dissolution rate of poorly soluble ingredients such as lutein, DHA microcapsules and plant extracts. Finally, EXCfiller®Carboxymethylcellulose sodium can be used as a microencapsulation material to encapsulate oxidation-prone and volatile components such as probiotics, fish oil and vitamin E, thereby enhancing storage stability.

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■ Production technology characteristics

The EXCfiller®Carboxymethylcellulose sodium production process involves three stages: alkalisation, etherification and post-treatment. The predominant method is solvent-based production, which yields high product purity and a uniform degree of substitution. A smaller proportion utilises the aqueous medium method, which is suitable for low-viscosity, low-substitution products. The core reaction involves the alkaline activation of cellulose, followed by carboxymethyl etherification.

Grind the wood pulp or cotton linters to a 20-40 mesh size to increase the specific surface area and ensure uniform alkali treatment. Dry at 105°C for 2-3 hours to reduce the moisture content of the cellulose to ≤8%, thereby preventing the dilution of the alkali solution. The alkalisation reaction (cellulose activation) involves the hydroxyl groups (-OH) on the cellulose molecular chains reacting with NaOH to form sodium cellulose salts. This breaks the intermolecular hydrogen bonds, thereby unfolding the molecular chains and creating active reaction sites. Etherification reaction (carboxymethyl substitution): The degree of substitution (DS) can be precisely controlled by adjusting the dosage of sodium chloroacetate, the reaction temperature and the reaction duration. A DS of 0.7-0.9 yields optimal water solubility, making it suitable for food and pharmaceutical applications. Post-processing (purification and modification) includes neutralisation, washing, drying and grinding/classification.

☑ EXCfiller®Carboxymethylcellulose sodium (Viscosity 750-1400 mPa.s)

☑ EXCfiller®Carboxymethylcellulose sodium (Viscosity 3000-5600 mPa.s)

☑ EXCfiller®Carboxymethylcellulose sodium (Viscosity 1500-2800 mPa.s)

☑ EXCfiller®Carboxymethylcellulose sodium (Viscosity 6000-11200 mPa.s)

☑ EXCfiller®Carboxymethylcellulose sodium (Viscosity 9000-16800 mPa.s)