Sodium Carboxymethylcellulose (Sodium CMC) is a water-soluble, cellulose-derived polymer used as a versatile cosmetic ingredient for viscosity control, thickening, stabilization, binding and film formation. It is produced by introducing carboxymethyl groups into cellulose and converting the resulting polymer into its sodium salt form.
Sodium Carboxymethylcellulose is commonly supplied as a white to off-white, free-flowing powder. When dispersed and hydrated in water, it forms a viscous colloidal solution. Its thickening performance depends on the polymer's degree of substitution, molecular-weight characteristics, concentration and viscosity grade.
Because it is a polymeric material, Sodium Carboxymethylcellulose is available in different grades designed for different viscosity and formulation requirements. The selection of an appropriate grade can influence product texture, flow, suspension behavior and stability.
Sodium Carboxymethylcellulose has the commonly used CAS Number 9004-32-4 and is also known as Carboxymethylcellulose Sodium, Sodium CMC, Cellulose Gum and Carmellose Sodium.
Its polymeric structure can be represented approximately as:
[C6H7O2(OH)x(OCH2COONa)y]n
where the degree of substitution and degree of polymerization vary according to the grade. USP defines Carboxymethylcellulose Sodium as the sodium salt of a polycarboxymethyl ether of cellulose and gives a sodium-content range of 6.5–9.5% on a dried basis for the cited monograph.
Because the substance is a polymer with variable substitution and molecular-weight distribution, it does not have one fixed molecular weight comparable to a small-molecule cosmetic raw material.
Sodium Carboxymethylcellulose functions primarily as a viscosity-controlling, thickening, stabilizing, binding and film-forming cosmetic ingredient.
Its ability to form viscous aqueous colloidal solutions makes it useful for adjusting the consistency of creams, lotions, gels, cleansers and other water-containing cosmetic systems. It can also contribute to suspension stability by increasing the viscosity of the continuous phase.
Sodium CMC can provide film-forming characteristics in suitable formulations and can help maintain a uniform product texture. Its water-compatible polymer structure makes it useful when formulators need a cellulose-derived thickener with controlled rheological properties.
The viscosity of Sodium Carboxymethylcellulose is strongly grade-dependent. USP specifications for Carboxymethylcellulose Sodium evaluate viscosity against the labeled grade rather than assigning one universal viscosity value.
Sodium Carboxymethylcellulose can be evaluated in a wide range of skin-care, hair-care and personal-care formulations.
Potential applications include facial gels, moisturizing creams, lotions, serums, cleansing products, shampoos, conditioners, body-care products and other aqueous or semi-solid cosmetic systems.
In creams and lotions, Sodium CMC can contribute to aqueous-phase viscosity and formulation consistency. In gels and serums, it can help create the desired rheological profile. In cleansing and hair-care formulations, it can support viscosity and suspension characteristics.
Sodium CMC can also be combined with Xanthan Gum, Hydroxyethylcellulose, Hydroxypropylcellulose, Hydroxypropyl Methylcellulose, Carbomer, Sodium Alginate and other hydrocolloids when a particular texture or viscosity profile is required.
Sodium Carboxymethylcellulose should be dispersed carefully to minimize agglomeration and ensure uniform hydration. The grade, particle size, concentration, mixing conditions and water quality can influence the final viscosity and appearance of the formulation.
Degree of substitution (DS) is an important technical characteristic because it influences water interaction and polymer functionality. Molecular-weight characteristics and viscosity grade are also important when selecting Sodium CMC for a particular application.
Sodium CMC is generally water-compatible, but formulators should evaluate its behavior in systems containing high electrolyte concentrations, strongly acidic or alkaline conditions, surfactants and other polymers.
The Assay (HPLC) field should not be populated with an arbitrary percentage. USP describes an assay based on sodium determination/titration rather than treating Sodium CMC as a conventional small-molecule HPLC analyte.
For quality control, relevant parameters can include sodium content, degree of substitution, viscosity, loss on drying, pH, ash, heavy metals, sodium chloride, sodium glycolate and microbiological quality.
Sodium Carboxymethylcellulose is a versatile cosmetic ingredient for manufacturers requiring controlled viscosity, thickening, stabilization, suspension and film-forming functionality.
For B2B sourcing, the exact grade should be selected according to viscosity, degree of substitution, molecular-weight characteristics, moisture, ash, pH and microbiological requirements. Different grades should not be treated as having identical specifications.
As a Sodium Carboxymethylcellulose Cosmetic Ingredient Manufacturer in India, the ingredient can support bulk cosmetic raw-material requirements for skin-care, hair-care, cleansing and personal-care manufacturers.
| Parameter | Specification |
|---|---|
| Appearance | White or colourless crystals / white powder |
| Loss on Drying | NMT 10.0% |
| Heavy Metals | NMT 20 ppm |
| pH (1% Solution) | 6.5–8.5 |