Calcium stearate occurs as a fine, white to yellowish-white, bulky powder having a slight, characteristic odor. It is unctuous and free from grittiness.
- BP: Calcium Stearate
- JP: Calcium Stearate
- PhEur: Calcium Stearate
- USP-NF: Calcium Stearate
Calcii stearas; calcium distearate; calcium octadecanoate; Deasit PC; HyQual; Kemistab EC-F; octadecanoic acid, calcium salt; stearic acid, calcium salt; Synpro.
Chemical Name and CAS Registry Number: Octadecanoic acid calcium salt [1592-23-0]
Empirical Formula and Molecular Weight
C36H70CaO4 607.03 (for pure material) The USP32–NF27 describes calcium stearate as a compound of calcium with a mixture of solid organic acids obtained from fats, and consists chiefly of variable proportions of calcium stearate and calcium palmitate. It contains the equivalent of 9.0–10.5% of calcium oxide.
The PhEur 6.3 describes calcium stearate as a mixture of calcium salts of different fatty acids consisting mainly of stearic acid [(C17
Functional Category: Tablet and capsule lubricant.
Applications in Pharmaceutical Formulation or Technology
Calcium stearate is primarily used in pharmaceutical formulations as a lubricant in tablet and capsule manufacture at concentrations up to 1.0% w/w. Although it has good antiadherent and lubricant properties, calcium stearate has poor glidant properties. Calcium stearate is also employed as an emulsifier, stabilizing agent, and suspending agent, and is also used in cosmetics and food products.
Method of Manufacture
Calcium stearate is prepared by the reaction of calcium chloride with a mixture of the sodium salts of stearic and palmitic acids. The calcium stearate formed is collected and washed with water to remove any sodium chloride
Magnesium stearate; stearic acid; zinc stearate.