Vegetable magnesium stearate comes from plant sources, but magnesium stearate can also come from animal sources. It is mainly used as an additive in pharmaceuticals and functions as a lubricant and binding agent.
Composition
Magnesium stearate is a salt of stearic acid, which is a fatty acid, and magnesium, which is a mineral. Commercial magnesium stearate also has some palmitic acid in it. Magnesium stearate can come from vegetable or animal (bovine) sources. Stearic acid is an 18-carbon-long saturated fatty acid. Magnesium stearate is a salt of that fatty acid and magnesium. As per the "International Pharmacopoeia (Fourth Edition)," commercial magnesium stearate consists mainly of magnesium stearate with variable amounts of magnesium palmitate and magnesium oleate. Magnesium stearate contains between 3.8 percent and 5.8 percent magnesium.
Sources
As per the NOW Foods website, coconut oil, cocoa butter and palm oil are vegetable oils that are high in stearic acid. These can be used to make vegetable magnesium stearate. Because of the recent increase in the threat of bovine diseases such as mad cow disease, foot and mouth disease and others, many magnesium stearate manufacturers are switching over from a bovine-derived version to a vegetable derived version of magnesium stearate.
Uses
Magnesium stearate is frequently used as an ingredient in tablets because it lubricates them and makes it easier for them to be ejected from the tablet press. It is also used as an excipient, also known as an inactive ingredient, in pharmaceutical tablets. As per an article by Gene Bruno, magnesium stearate usually makes up 0.25 to 1.5 percent of a tablet's weight.
Bathtub Rings
Bathtub rings are mainly made of magnesium stearate. When soap is used with hard water, the calcium and magnesium ions in the water precipitate out and combine with stearate in the soap to form bathtub rings.
Safety
Magnesium stearate is safe in amounts normally consumed. According to an article by Gene Bruno, magnesium stearate is safe in the amounts used in pharmaceutical tablets. He pointed out that one-half bar of milk chocolate has around 112 calories and has 1,283 mg of stearic acid, which is much more than is found in pharmaceutical tablets.
References
- "Journal Of Pharmaceutical Sciences"; Functionality of Magnesium Stearate Derived from Bovine and Vegetable Sources: Dry Granulated Tablets; Hamad, M., Gupta, A., Shah, R., Lyon, R., Sayeed, V., and KHAN, M.; Vol. 97, No. 12, December 2008, p. 5328--5340
- "International Pharmacopoeia: Fourth Edition"; MAGNESIUM STEARATE; The International Pharmacopoeia; 2006, Vol. 1, p569-571
- "Virtual Chembook, Elmhurst College"; Soap; Ophardt, C., 2003
- "NOW Foods"; Stearic Acid and Magnesium Stearate; Levin, N.; 2002-2009
- "Natural Products Marketplace"; Safety of Stearic Acid, Magnesium Stearate, Bruno, G.; December 22, 2009
Member Comments