Magnesium stearate

Description

Magnesium stearate, also called octa decanoic acid, magnesium salt, is a white substance, powder which becomes solid at room temperature. It has the chemical formula Mg(C₁₈H₃₅O₂)₂. It is a salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+). Magnesium stearate melts at about 120 °C, is not soluble in water, and is generally considered safe for human consumption at levels below 2500 mg/kg per day.In 1979, the FDA's Subcommittee on GRAS (generally recognized as safe) Substances (SCOGS) reported, "There is no evidence in the available information on ... magnesium stearate ... that demonstrates, or suggests reasonable grounds to suspect, a hazard to the public when they are used at levels that are now current and in the manner now practiced, or which might reasonably be expected in the future.".

Chemical properties

Magnesium stearate is a very fine, light white, precipitated or milled, impalpable powder of low bulk density, having a faint odor of stearic acid and a characteristic taste. The powder is greasy to the touch and readily adheres to the skin. nonflammable used in baby dusting powder(s) and as tablet lubricant.

Chemical properties

Magnesium stearate is a compound of magnesium with a mixture of solid organic acids obtained from edible sources and consists chiefly of variable proportions of magnesium stearate and magnesium palmitate. It occurs as a fine, white, bulky powder having a faint, characteristic odor. It is unctuous and is free from grittiness. It is insoluble in water, in alcohol, and in ether. It conforms to the regulations of the U.S. Food and Drug Administration pertaining to specifications for salts of fatty acids derived from edible fat sources.

The Uses of Magnesium stearate

Magnesium Stearate is the magnesium salt of stearic acid which functions as a lubricant, binder, emulsifier, and anticaking agent. it is a white powder that is insoluble in water. it is used as a lubricant or die release in tableting pressed candies and is also used in sugar- less gum and mints.

The Uses of Magnesium stearate

widely used in the fields of the plastic, mold-releasing agent for tablets (need meeting the medicine criterion), emulsifying agents of cosmetics. It also can conjugate with Ca Soap as stabilizer of PVC.

The Uses of Magnesium stearate

Magnesium stearate is often used as a anti-adherent in the manufacture of medical tablets, capsules and powders. In this regard, the substance is also useful, because it has lubricating properties, preventing ingredients from sticking to manufacturing equipment during the compression of chemical powders into solid tablets; magnesium stearate is the most commonly used lubricant for tablets. Studies have shown that magnesium stearate may affect the release time of the active ingredients in tablets, etc., but not that it reduces the overall bioavailability of those ingredients. As a food additive or pharmaceutical excipient, its E number is E470b.
Magnesium stearate is also used to bind sugar in hard candies like mints, and is a common ingredient in baby formulas. In pure powder form, the substance can be a dust explosion hazard, although this issue is effectively insignificant beyond the manufacturing plants using it.
Magnesium stearate is manufactured from both animal and vegetable oils. Some nutritional supplements specify that the magnesium stearate used is sourced from vegetables.
Magnesium stearate is a major component of "bathtub rings." When produced by soap and hard water, magnesium stearate and calcium stearate both form a white solid insoluble in water, and are collectively known as "soap scum.".

Definition

Mg(C18H35O2)2 or with one H2O. Technical grade contains small amounts of the oleate and 7% magnesium oxide, MgO.

Production Methods

Magnesium stearate is prepared either by the interaction of aqueous solutions of magnesium chloride with sodium stearate or by the interaction of magnesium oxide, hydroxide, or carbonate with stearic acid at elevated temperatures.

Preparation

Magnesium stearate is created by the reaction of sodium stearate with magnesium sulfate.

General Description

Magnesium stearate (Mg-St) is the magnesium salt of stearic acid. Its anhydrate, dihydrate and trihydrate forms have been prepared. The tabletting of the blends of magnesium stearate and lactose granules has been described. The influence of mixing time on hardness, disintegration time and ejection force on the compressed tablets was examined. Mg-St is widely used lubricant in pharmaceutical industry. It also plays a role in delaying the process of dissolution. Its detection in tablets by laser-induced breakdown spectroscopy has been proposed.

Pharmaceutical Applications

Magnesium stearate is widely used in cosmetics, foods, and pharmaceutical formulations. It is primarily used as a lubricant in capsule and tablet manufacture at concentrations between 0.25% and 5.0% w/w. It is also used in barrier creams.

Biochem/physiol Actions

Magnesium stearate is the magnesium salt of stearic acid that possess lubricating properties and hence prevents ingredients from sticking to manufacturing equipment during the compression of chemical powders into solid tablets. Dry coating of drugs with magnesium stearate leads to flow improvement, flow-aid and lubrication effects, tabletability as well as non-inhibited dissolution rate.

Safety Profile

Slightly toxic by ingestion. Spontaneously combustible. When heated to decomposition it emits acrid smoke and toxic fumes.

Safety

Magnesium stearate is widely used as a pharmaceutical excipient and is generally regarded as being nontoxic following oral administration. However, oral consumption of large quantities may produce a laxative effect or mucosal irritation.
No toxicity information is available relating to normal routes of occupational exposure. Limits for heavy metals in magnesium stearate have been evaluated in terms of magnesium stearate worstcase daily intake and heavy metal composition.
Toxicity assessments of magnesium stearate in rats have indicated that it is not irritating to the skin, and is nontoxic when administered orally or inhaled.
Magnesium stearate has not been shown to be carcinogenic when implanted into the bladder of mice.
LD₅₀ (rat, inhalation): >2 mg/L
LD₅₀ (rat, oral): >10 g/kg

storage

Magnesium stearate is stable and should be stored in a well-closed container in a cool, dry place.

Incompatibilities

Incompatible with strong acids, alkalis, and iron salts. Avoid mixing with strong oxidizing materials. Magnesium stearate cannot be used in products containing aspirin, some vitamins, and most alkaloidal salts.

Regulatory Status

GRAS listed. Accepted as a food additive in the USA and UK. Included in the FDA Inactive Ingredients Database (oral capsules, powders, and tablets; buccal and vaginal tablets; topical preparapreparations; intravitreal implants and injections). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients. Listed on the US TSCA inventory.