Magnesium stearate, a compound of magnesium salt and stearic acid, is widely used in the pharmaceutical industry to bind tablets and make them smooth. The chemical is a key ingredient for many cosmetic products including eyeliner, eye shadow, mascara and lipsticks. It's also a common additive in many foods.
Synonyms
Other names for magnesium stearate include octadecanoic acid, magnesium salt, magnesium distearate and dibasic magnesium stearate.
Chemistry Behind Magnesium Stearate
Magnesium stearate consists of a magnesium salt joined by an ionic bond to two stearic acid molecules. Stearic acid, a saturated fat, is 18 carbons long and is common in our diet. This gives magnesium stearate a complex molecular formula of Mg (C18H35O2)2. It is quickly metabolized to oleic acid (the fatty acid found in olive oil). According to WellnessResources.com, stearic acid does not raise LDL (bad cholesterol) levels as much as other fatty acids.
Physical Properties
Magnesium stearate is a fine, white powder with a slight fatty acid odor and is greasy to the touch. Since magnesium stearate is a fatty acid, it is hydrophobic, meaning it is incapable of dissolving in water. Magnesium stearate is, however, slightly soluble in warm ethanol and warm benzene. The compound has a melting point between 190 to 194 degrees Fahrenheit. It has a flash point of 482 degrees Fahrenheit.
Safety
Although some health experts worry about adding magnesium stearate to medicines and supplements, the Food and Drug Administration regards it as "generally safe." However, ingestion of large amounts may have laxative effects or irritation of mucous membranes. According to Rockwellnutrition.com, toxicological experiments in rats and mice showed that magnesium stearate is non-toxic when taken orally or inhaled and does not irritate the skin. In addition, research has shown that the chemical is not carcinogenic.
Member Comments