Products
Calcium stearate is found as an excipient in drugs, especially in tablets. However, the closely related magnesium stearate is much more commonly used in practice.
Structure and properties
Calcium stearate is a mixture of calcium salts of various fatty acids, mainly stearic acid and palmitic acid with a small proportion of other fatty acids. The proportion of stearic acid in the fatty acid fraction must be at least 40%. Calcium stearate exists as a white, fine, crystalline powder and is practically insoluble in water.
Effects
Calcium stearate is a lubricant. It provides a smooth surface for tablets and prevents the powder from sticking to the tablet press. Calcium stearate improves lubricity by reducing friction and adhesion.
Fields of application
Calcium stearate is mainly used as a lubricant for tablet production.