Magnesium stearate

Structural formula
General
Surname	Magnesium stearate
other names	MAGNESIUM STEARATE ( INCI )
Molecular formula	C 36 H 70 MgO 4
Brief description	White dust
External identifiers / databases
CAS number 557-04-0 EC number 209-150-3 ECHA InfoCard 100.008.320 PubChem 11177 ChemSpider 10704 DrugBank DB14077 Wikidata Q416713
properties
Molar mass	591.25 g mol −1
Physical state	firmly
density	1.03 g cm −3 (22 ° C)
Melting point	approx. 140 ° C
solubility	almost insoluble in water
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Magnesium stearate is the magnesium salt of stearic acid and is one of the lime soaps .

It is obtained from fats and oils by splitting their glycerides with magnesium, soaps and glycerine . Magnesium stearate is used, for example, in the pharmaceutical industry as an aid for making tablets or granules . Magnesium stearate is also used in some sweets.

Magnesium stearate can be made from both animal and vegetable fats. Soy, rapeseed or corn oil is often used.

properties

Magnesium stearate in its use form in the pharmaceutical industry still contains small amounts of other magnesium salts, e.g. B. palmitic acid and oleic acid . Overall, the result is a fine, almost odorless white powder that is greasy to the touch. The solubility in water and ethanol is practically non-existent.

Magnesium stearate shows properties that make it very suitable as a lubricant . For one, it has a lamellar crystal structure, which greatly reduces the internal friction of the fabric. It also has a very small particle size of 3 to 15 µm. Magnesium stearate accumulates on the surface of other particles of a powder mixture and thus reduces their friction with one another and with external surfaces, e.g. B. a tablet press .

See also

• Calcium behenate

Individual evidence

1. ↑ Entry on MAGNESIUM STEARATE in the CosIng database of the EU Commission, accessed on March 7, 2020.
2. ↑ ^{a b c d e f} Entry on magnesium stearate in the GESTIS substance database of the IFA , accessed on September 8, 2017(JavaScript required) .
3. ↑ Rudolph Hansel, Otto Sticher (Ed.): Pharmakognosie - Phytopharmazie . 9th edition. Springer Medicine, Heidelberg 2010, ISBN 978-3-642-00962-4 , p. 255 .
4. ↑ Additives database: Magnesium salts of fatty acids .
5. ↑ ^{a b} Voigt, Rudolf: Voigt Pharmaceutical technology for study and work . 12th, completely revised edition. Deutscher Apotheker Verlag, Stuttgart 2015, ISBN 978-3-7692-6194-3 .