Magnesium stearate

CAS 557-04-0[CH3(CH2)16CO2]2MgChemical Synthesis

Magnesium stearate (CAS: 557-04-0), with the chemical formula [CH3(CH2)16CO2]2Mg and a molecular weight of 591.24 g/mol, is a white powder recognised for its lubricating properties. It is commonly employed in pharmaceutical manufacturing as an excipient to prevent tablet sticking during compression and to facilitate capsule filling. Its utility extends to the preparation of microcapsules, making it a valuable compound in various chemical synthesis and analytical applications.

IUPAC: Stearic acid magnesium salt

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Magnesium stearate ([CH3(CH2)16CO2]2Mg) — chemical structure, CAS 557-04-0; Chemistry, fine chemical supplied by Tech Serve Solutions

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01 /Applications

Tablet and Capsule Lubrication

Magnesium stearate serves as an essential lubricant in tablet and capsule manufacturing. It prevents the formulation from adhering to the punches and dies of tablet presses and the filling mechanisms of capsule machines, ensuring smooth production and consistent product quality.

Microencapsulation Agent

This compound has been utilised in the development of microcapsules. Its properties allow for the controlled release or protection of active ingredients within a polymeric matrix, finding application in controlled drug delivery systems and other specialised formulations.

Chemical Synthesis

As a carboxylic acid salt and an organic building block, magnesium stearate finds use in various chemical synthesis pathways. Its structure and reactivity make it a component in the creation of more complex organic molecules.

Analytical and Chromatography

In analytical chemistry, magnesium stearate can be employed in chromatography applications, potentially as a stationary phase component or as a derivatising agent, contributing to the separation and analysis of chemical mixtures.

02 /Properties

Molecular weight	591.24
Linear formula	[CH3(CH2)16CO2]2Mg
Assay	≥40% stearic acid basis (GC)≥90% stearic and palmitic acid basis4.0-5.0% Mg basis (calc on dry sub.)
Grade	puriss.
Solubility	alcohol: insolublediethyl ether: insolublewater: insoluble
Loss on drying	≤6.0% loss on drying, 105 °C
Impurities tested	acidity or alkalinity, compliesmicrobiological impurity, in accordanceresidual solvents, complies
Melting point	200 °C(lit.)
Application	Magnesium stearate has been used as a tablet and capsule lubricant.1 It has also been used for preparing microcapsules.2
Suitability	in accordance for fatty acid compositionpasses test for identity

03 /Safety & handling

GHS hazard pictogram: Harmful / irritant (GHS07) — Harmful / irritant

Warning

Hazard statements

H315Causes skin irritation
H319Causes serious eye irritation
H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust, fume, gas or vapours
P305IF IN EYES

Protective equipment	dust mask type N95 (US), Eyeshields, Gloves
Water hazard class (WGK, DE)	nwg
Hazard codes (EU)	Xi
Risk statements (R)	36/37/38
Safety statements (S)	26
Cation traces	Cd: ≤3 mg/kgNi: ≤5 mg/kgPb: ≤10 mg/kg
Anion traces	chloride (Cl-): ≤1000 mg/kgsulfate (SO42-): ≤5000 mg/kg

Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.

04 /Identifiers & registry

CAS number

557-04-0

MDL number

MFCD00036391

Beilstein registry

3919702

05 /Additional specifications

Quality	meets analytical specification of Ph.
Acid Value	195‑210(fatty acid)

06 /Quality & supply

Documentation

Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.

Supply & logistics

Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.

07 /Frequently asked questions

What is Magnesium Stearate used for?

Magnesium stearate is primarily used as a lubricant in tablet and capsule manufacturing to prevent sticking during production. It is also utilised in preparing microcapsules and in various chemical synthesis and analytical applications.

What is the CAS number and chemical formula for Magnesium Stearate?

The CAS number for Magnesium Stearate is 557-04-0, and its chemical formula is [CH3(CH2)16CO2]2Mg.

What grade and purity does Tech Serve Solutions supply?

Tech Serve Solutions supplies Magnesium Stearate with a 'puriss.' grade, meeting analytical specifications of Ph. The assay indicates ≥40% stearic acid basis (GC), ≥90% stearic and palmitic acid basis, and 4.0-5.0% Mg basis (calc on dry sub.). TSS does not represent this product as USP, BP, or EP grade unless explicitly stated in the product specifications.

What are the safety considerations for handling Magnesium Stearate?

Magnesium Stearate is a GHS07 substance with a signal word of Warning, carrying hazard statements H315 (Causes skin irritation), H319 (Causes serious eye irritation), and H335 (May cause respiratory irritation). Appropriate personal protective equipment includes a dust mask (type N95 or equivalent), eyeshields, and gloves. Handle in a well-ventilated area and avoid dust formation.

How is Magnesium Stearate packed and shipped?

Magnesium Stearate is carefully packed to maintain its integrity during transit. Tech Serve Solutions handles the export of this chemical globally. Please contact us for specific packing and shipping details relevant to your region and order requirements.

How can I request a sample or quote for Magnesium Stearate?

To request a sample or a quote for Magnesium Stearate, please use the contact form on our website or reach out to our sales team directly. Provide your contact details and the quantity required.