Carboxymethylcellulose calcium

• BPCarmellose Calcium
• JPCarmellose Calcium
• Ph. Eur.Carmellose Calcium
• USP–NFCarboxymethylcellulose Calcium

Calcium carboxymethylcellulose; calcium CMC; carmellosum calcicum; cellulose, carboxymethyl ether, calcium salt; ECG 505

Cellulose, carboxymethyl ether, calcium salt · [9050-04-8]

Polymer, mixture or material of variable composition — no single molecular formula applies.

Disintegrant

Typical concentrations: 1–15% · Dosage forms: Solid

Used in oral and topical products mainly for its water-absorbing and swelling properties: as a tablet disintegrant and binder, and as a suspending or viscosity-increasing agent. In tablets it is typically used at about 1–15% w/w.

A white to yellowish-white, hygroscopic, odourless fine powder.

pH

≈ 4.5–6.0 (1% w/v aqueous dispersion)

Solubility

practically insoluble in water, ethanol, acetone and ether; swells in water to form a suspension; slightly soluble in dilute sodium hydroxide

Hygroscopicity

hygroscopic

Stable but hygroscopic. Store in a well-closed container in a cool, dry place.

As with carboxymethylcellulose sodium, it is incompatible with strongly acidic solutions and with soluble salts of iron and some other metals such as aluminium, mercury and zinc.

Cellulose is carboxymethylated with chloroacetic acid in the presence of sodium hydroxide; the sodium salt is converted to the acid form and then to the calcium salt, for example with calcium carbonate.

Used in oral pharmaceuticals and regarded as non-toxic and non-irritant; it is not absorbed. Very large oral amounts may have a laxative effect.

Observe normal precautions for the quantity handled. Avoid inhaling the dust; eye protection and gloves are recommended.

Included in the FDA Inactive Ingredient Database (oral capsules and tablets) and in non-parenteral medicines licensed in Europe.

Carboxymethylcellulose sodium; croscarmellose sodium; sodium starch glycolate.

Unlike the sodium salt, the calcium salt is insoluble in water; it swells instead of dissolving, which is why it works as a disintegrant rather than a thickener. It is used particularly widely in Japan.