Magnesium Stearate, Magnesium Distearate, Magnesium Octadeconate, Magnesium Soap, 557-04-4

Magnesium Stearate, Magnesium Distearate, Magnesium Octadeconate, Magnesium Soap, 557-04-4

MAGNESIUM STEARATE

Magnesium Stearate / Magnesium Distearate / Magnesium Octadecanoate / Magnesium Soap
CAS Number: 557-04-4
EC Number: 209-150-3

1. IDENTIFICATION INFORMATION

2. PHYSICAL PROPERTIES

3. CHEMICAL PROPERTIES

Molecular Structure:

        O              O
        ||             ||
C₁₇H₃₅-C-O⁻  Mg²⁺  ⁻O-C-C₁₇H₃₅

Formation Reaction:

2 C₁₇H₃₅COOH (Stearic Acid) + Mg(OH)₂ → Mg(C₁₇H₃₅COO)₂ + 2 H₂O

4. PRODUCTION PROCESS

Reaction Equation (Double Decomposition - Most Common):

2 C₁₇H₃₅COONa + MgSO₄ → Mg(C₁₇H₃₅COO)₂ + Na₂SO₄

Reaction Equation (Direct Reaction):

2 C₁₇H₃₅COOH + Mg(OH)₂ → Mg(C₁₇H₃₅COO)₂ + 2 H₂O

Typical Grades:

5. AVAILABLE FORMS AND SPECIFICATIONS

Typical Specifications (Pharmaceutical Grade):

Typical Specifications (Food Grade):

6. APPLICATIONS

6.1. Pharmaceutical Industry – Largest Use (~40%)

Pharmaceutical Applications Details:

6.2. Cosmetic Industry

Lubrication Property: Provides lubricating effect, prevents adhesion to skin in cosmetic products.

6.3. Food Industry

6.4. Plastics and Rubber Industry

6.5. Paints and Coatings

6.6. Construction and Building Materials

6.7. Other Applications

7. PHARMACEUTICAL GRADE COMPARISON

8. PHYSICAL AND CHEMICAL SPECIFICATIONS

8.1. Solubility Profile

8.2. Particle Size Distribution (Pharmaceutical Grade)

8.3. Other Physical Properties

9. STORAGE AND HANDLING

Handling Notes:

• Forms lumps if exposed to high humidity (slightly hygroscopic)

• May cause dust explosion risk (organic dust)

• Use local exhaust ventilation when handling large quantities

• Avoid prolonged skin contact (may cause irritation)

• Use dust mask if significant dust generation occurs

10. SAFETY AND HEALTH INFORMATION (GHS CLASSIFICATION)

Note: Magnesium stearate is generally recognized as safe (GRAS) by FDA for food and pharmaceutical applications.

11. HAZARD STATEMENTS (H-CODES)

12. SAFETY STATEMENTS (P-CODES)

13. TOXICOLOGICAL INFORMATION

Health Effects:

Regulatory Status:

14. FIRST AID MEASURES

15. FIRE FIGHTING MEASURES

16. ENVIRONMENTAL INFORMATION

17. TRANSPORT INFORMATION

18. REGULATORY INFORMATION

FDA Compliance: 21 CFR 184.1440 (GRAS for direct human food)

EU Compliance: Food additive E572 (anti-caking agent)

Pharmaceutical Compliance: USP/NF, Ph. Eur., JP

Halal Certification: Available from certified suppliers

Kosher Certification: Available from certified suppliers

19. OTHER NAMES AND SYNONYMS

Chemical Name: Octadecanoic acid, magnesium salt (2:1)

Database Identifiers:

20. SUMMARY AND IMPORTANT WARNINGS

SUMMARY:

Magnesium stearate (C₃₆H₇₀MgO₄, CAS 557-04-4) is a white, tasteless, odorless powder formed by two stearate anions bonded to one divalent magnesium cation (Mg²⁺). It is an anionic surfactant and metallic salt with very low water solubility (~3-8 mg/100 mL) but soluble in warm organic solvents. The largest application is in the pharmaceutical industry (~40%) as a tablet lubricant and anti-adherent to prevent sticking during compression. It is also widely used in cosmetics (emulsifier, consistency enhancer), food industry (emulsifier, anti-caking agent E572), plastics and rubber (release agent, lubricant), and paints (flatting agent, sanding agent).

Key Properties:

Main Application Areas:

Physical Forms:

Key Safety Points:

• LOW TOXICITY: Very low acute toxicity (LD50 > 10,000 mg/kg)

• GRAS STATUS: Generally Recognized as Safe by FDA (21 CFR 184.1440)

• MILD IRRITANT: May cause mild skin and eye irritation

• DUST EXPLOSION: Combustible dust; avoid dust cloud formation

• SLIGHTLY HYGROSCOPIC: Protect from moisture

• USE PPE: Dust mask, gloves, safety goggles (if dust generation occurs)

IMPORTANT WARNINGS:

Pharmaceutical Lubricant: Magnesium stearate is the most widely used tablet lubricant in the pharmaceutical industry. It prevents sticking of tablet formulations to punches and dies during high-speed compression. However, over-lubrication (excessive use >1-2%) can reduce tablet hardness and delay drug dissolution (hydrophobic barrier effect). Typical concentration: 0.25% - 2.0%.

Hydrophobic Barrier: Due to its highly hydrophobic nature, excessive magnesium stearate can coat drug particles and reduce dissolution rate. This is particularly critical for poorly soluble drugs. Formulators must optimize concentration.

DPI Carrier: In dry powder inhalation (DPI) formulations, magnesium stearate serves as a carrier particle that protects hydrolysis-sensitive active ingredients from degradation. It also improves powder flow and aerosolization properties.

Anionic Surfactant: As a fatty acid salt, magnesium stearate is an anionic surfactant. It exhibits stability performance similar to calcium stearate.

Crystal Forms: Magnesium stearate exists in multiple crystalline forms (anhydrate, monohydrate, dihydrate, trihydrate) which can affect its lubricant performance. The hydrate form is most common.

Compatibility: Magnesium stearate is incompatible with strong oxidizing agents and strong acids (hydrolyzes to stearic acid). It may interact with certain active pharmaceutical ingredients containing functional groups that react with stearate.

Dust Explosion: Although not classified as an explosive, magnesium stearate dust can form combustible dust clouds. Use appropriate grounding and dust collection systems. Avoid static electricity buildup.

Food Additive E572: In the EU, magnesium stearate is approved as food additive E572 (anti-caking agent) with no specified maximum limit (quantum satis).

Environmental: Magnesium stearate is readily biodegradable and has low aquatic toxicity. However, avoid large discharges to water bodies.

Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS) provided by the manufacturer/supplier.