Carboxymethylcellulose calcium occurs as a white to yellowishwhite,
hygroscopic, odorless powder.
Pharmaceutic aid (tablet
disintegrant).
Cellulose, obtained from wood pulp or cotton fibers, is carboxymethylated,
followed by conversion to the calcium salt. It is then
graded on the basis of its degree of carboxymethylation and
pulverized.
Pharmaceutical Applications
The main use of carboxymethylcellulose calcium is in tablet
formulations, where it is used as a binder, diluent,
and disintegrant. Although carboxymethylcellulose calcium is
insoluble in water, it is an effective tablet disintegrant as it swells to
several times its original bulk on contact with water. Concentrations
up to 15% w/w may be used in tablet formulations; above this
concentration, tablet hardness is reduced.
Carboxymethylcellulose calcium is also used in other applications
similarly to carboxymethylcellulose sodium; for example, as a
suspending or viscosity-increasing agent in oral and topical
pharmaceutical formulations. Carboxymethylcellulose calcium is
also used in modern wound dressings for its water absorption,
retention and hemostatic properties.
Carboxymethylcellulose calcium is used in oral and topical
pharmaceutical formulations, similarly to carboxymethylcellulose
sodium, and is generally regarded as a nontoxic and nonirritant
material. However, as with other cellulose derivatives, oral
consumption of large amounts of carboxymethylcellulose calcium
may have a laxative effect.
Carboxymethylcellulose calcium is a stable, though hygroscopic
material. It should be stored in a well-closed container in a cool, dry
place.
Included in the FDA Inactive Ingredients Database (oral, capsules
and tablets). Included in nonparenteral medicines licensed in the
UK. Included in the Canadian List of Acceptable Non-medicinal
Ingredients.