Methylcellulose vs. Carboxymethylcellulose — What's the Difference?

Methylcellulose (MC), derived from cellulose, is a chemical compound that acts as a thickener, emulsifier, and film-former in various applications, including food, pharmaceuticals, and construction. It is water-soluble, forming a gel when heated, and is unique for its thermal gelation properties. Carboxymethylcellulose (CMC), also derived from cellulose, is a carboxylated derivative of methylcellulose. It shares similar uses with MC, such as in food and pharmaceuticals, but its carboxyl groups make it more versatile. CMC offers higher viscosity and better stability, making it preferable in more demanding applications.

While both compounds are used as thickeners and stabilizers, their chemical structures influence their solubility and interaction with other substances. MC is soluble in cold water and gels upon heating, which is useful in foods and products that require temperature-sensitive gelation. CMC, with its carboxyl groups, provides higher viscosity solutions at lower concentrations and is more effective in a wider range of temperatures and pH levels.

In the pharmaceutical industry, MC is often used as a laxative and as a disintegrant in tablets, whereas CMC's higher viscosity and better mucoadhesiveness make it suitable for use in eye drops, as a binder in tablets, and in wound care products.

In food applications, MC is used to improve texture and retain moisture in baked goods, while CMC is often found in ice cream, where it prevents ice crystal formation, and in gluten-free baking, where it helps mimic the texture of gluten.