Calcium stearate

• BPCalcium Stearate
• JPCalcium Stearate
• Ph. Eur.Calcium Stearate
• USP–NFCalcium Stearate

Calcii stearas; calcium distearate; calcium octadecanoate; octadecanoic acid, calcium salt; stearic acid, calcium salt; E470a

Octadecanoic acid calcium salt · [1592-23-0]

UNII 776XM7047L · PubChem CID 15324

C36H70CaO4 · 607.0

Lubricant

Typical concentrations: up to 1% · Dosage forms: Solid

Used mainly as a lubricant in tablet and capsule manufacture, usually at up to about 1% w/w. It is also used as an emulsifier and stabiliser, as a water-repellent and anticaking agent, and in foods and cosmetics.

A fine, white to yellowish-white, bulky powder with a slight, characteristic odour. It is unctuous to the touch and free from grittiness.

Composition

mixture of calcium salts of fatty acids, mainly stearic and palmitic acid; Ph. Eur. requires stearic acid ≥ 40% and stearic plus palmitic acid ≥ 90% of the fatty-acid fraction

Calcium content

6.4–7.4% (dried substance, Ph. Eur.)

Melting behaviour

softens and melts at about 150–160 °C (grade-dependent)

Solubility

practically insoluble in water, ethanol and ether; slightly soluble in hot ethanol and in hot vegetable and mineral oils

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

Incompatible with strong oxidising agents and strong acids. Like other metallic stearates it is hydrophobic and can slow wetting and dissolution if over-blended.

Prepared by reacting a soluble calcium salt such as calcium chloride with sodium stearate in aqueous solution, or by reacting calcium oxide or hydroxide with stearic acid.

Used in oral pharmaceuticals and foods and regarded as non-toxic and non-irritant at the levels employed.

Observe normal precautions for the quantity handled. Eye protection, gloves and a dust mask are recommended where dust is generated.

GRAS listed. Accepted as a food additive in Europe (E470a). Included in the FDA Inactive Ingredient Database (oral capsules and tablets) and in non-parenteral medicines licensed in Europe.

Magnesium stearate; stearic acid; zinc stearate; sodium stearyl fumarate.

Calcium stearate is used less often than magnesium stearate but is an alternative where magnesium stearate is unsuitable; as with all metallic stearate lubricants, the lowest effective level and short blending times are advisable.