Sodium Stearyl Fumarate, Sodium Octadecyl Fumarate, SSF, 4070-80-8

SODIUM STEARYL FUMARATE (SSF)

Product Name: Sodium Stearyl Fumarate (SSF)
CAS Number: 4070-80-8
Molecular Formula: C₂₂H₃₉NaO₄
Molecular Weight: ~390.5 g/mol
Chemical Class: Pharmaceutical excipient (lubricant / glidant)

SECTION 1: PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

PRODUCT DESCRIPTION AND EXPLANATION:

Sodium Stearyl Fumarate (SSF) is a widely used lubricant and flow-regulating excipient in pharmaceutical tablet manufacturing. Developed as an alternative to magnesium stearate, it is preferred particularly due to its hydrophilic structure, which has less negative impact on the dissolution profile of tablets compared to magnesium stearate.

The molecular structure consists of a long hydrocarbon chain (stearyl group) and a fumarate salt group. This structure gives SSF both lubricant and surface-active properties. In the pharmaceutical industry, it is preferred in formulations produced by direct compression and granulation methods, especially for active pharmaceutical ingredients (APIs) with low aqueous solubility or critical dissolution rates.

SSF is a more hydrophilic lubricant compared to magnesium stearate. This property means it does not form a hydrophobic layer on the tablet surface, so it does not hinder water penetration and drug dissolution. Therefore, it provides a significant advantage over magnesium stearate in drug formulations where solubility is critical. Additionally, the risk of over-lubrication is lower compared to magnesium stearate, providing a wider processing window during formulation development.

SECTION 2: PHYSICAL AND CHEMICAL PROPERTIES

SOLUBILITY PROFILE:

PHYSICAL AND CHEMICAL PROPERTIES EXPLANATION:

Sodium Stearyl Fumarate is a white or off-white, fine powder form pharmaceutical excipient. The melting point is approximately 220°C, at which thermal decomposition begins; therefore, the melting point is also considered the decomposition temperature.

With a density of ~1.1 g/cm³, SSF has a medium density value among typical pharmaceutical powders. Bulk density (0.30-0.50 g/cm³) and tapped density (0.40-0.65 g/cm³) provide information about powder flow properties and behavior during tablet compression. Typical particle size is in the range of 10-30 µm (d50), which provides homogeneous distribution and optimal lubricant performance.

SSF has low solubility in water (~0.1 g/L, 25°C) and forms suspensions in aqueous media. It is slightly soluble in methanol, while it shows insolubility in organic solvents such as ethanol, acetone, and chloroform. Solubility increases in hot water. This solubility profile enables SSF to function as a lubricant in tablet formulations; its insolubility in water maintains tablet integrity while its hydrophilic structure does not negatively affect the dissolution profile.

SECTION 3: CHEMICAL PROPERTIES AND REACTIONS

CHEMICAL PROPERTIES EXPLANATION:

Sodium Stearyl Fumarate is a sodium salt and fatty acid derivative. The fumarate group (C=C double bond) and carboxylate salt (-COONa) along with the long C18 alkyl chain give SSF amphiphilic (both hydrophilic and hydrophobic) properties. This structure forms the basis of SSF's lubricant and surface-active characteristics.

The pH value (~6.0-8.0 in 10 g/L suspension) indicates a slightly alkaline character. Thermal decomposition begins at approximately 220°C, above which CO₂ and various hydrocarbons are released. Therefore, processing temperatures used in tablet manufacturing (typically <100°C) do not pose a decomposition risk.

SSF may undergo slow hydrolysis in the presence of moisture, potentially forming stearyl alcohol and fumaric acid derivatives. For this reason, storing the product in dry conditions is important. Due to the double bond (-CH=CH-) in the alkyl chain, SSF may be sensitive to oxidation during long-term storage; the presence of antioxidants or storage under inert gas can extend shelf life.

Its amphiphilic structure gives SSF surface-active properties, allowing it to function as both a lubricant and a wetting agent in tablet formulations. The HLB (Hydrophilic-Lipophilic Balance) value is approximately 14, indicating that SSF is dispersible in water and can reduce surface tension.

SECTION 4: FUNCTIONAL PROPERTIES AND MECHANISM OF ACTION

FUNCTIONAL PROPERTIES EXPLANATION:

The primary function of Sodium Stearyl Fumarate is to serve as a lubricant in tablet manufacturing. During tablet compression, SSF particles form a thin film layer on the surface of API and other excipient particles. This layer reduces interparticle friction, improves powder flow, and ensures smooth ejection of tablets from the die.

The most important advantage of SSF is its greater hydrophilicity compared to magnesium stearate. Magnesium stearate can form a hydrophobic layer on tablet surfaces, delaying water penetration and drug dissolution. SSF, with its hydrophilic structure, minimizes this negative effect, providing a significant advantage especially for drugs with critical solubility.

The risk of over-lubrication is lower with SSF compared to magnesium stearate. While excessive use of magnesium stearate can cause decreased tablet hardness and slower dissolution rates, SSF can be safely used in a wider concentration range (typically 0.5-2.0%). This property provides greater flexibility during formulation development.

SSF is typically used at 0.5-2.0% concentration, and within this range, it does not negatively affect tablet hardness or disintegration time. It also improves powder flow properties, ensuring homogeneous filling and weight consistency during tablet compression.

SECTION 5: APPLICATION AREAS AND INDUSTRIAL USES

5.1. Pharmaceutical Industry (Primary Application)

5.2. Food Industry

5.3. Cosmetic Industry

APPLICATION AREAS EXPLANATION:

Pharmaceutical Industry:

The most important and widespread use of Sodium Stearyl Fumarate is as a lubricant in pharmaceutical tablet production. SSF is preferred in cases where the negative effect of magnesium stearate's hydrophobic structure on dissolution profile must be avoided. Particularly:

• Low solubility APIs: For BCS (Biopharmaceutics Classification System) Class II and IV drugs (low solubility, high/low permeability), SSF provides a significant advantage over magnesium stearate.

• Fast disintegrating tablets: SSF is preferred in orally disintegrating tablets (ODT) and fast-dissolving formulations because it does not hinder rapid disintegration.

• Effervescent tablets: SSF performs better than magnesium stearate in effervescent tablet formulations.

• Direct compression formulations: SSF functions as both a lubricant and flow enhancer in direct compression tablets.

Typical use concentration is 0.5-2.0%, which provides optimal lubrication and flow properties without negatively affecting tablet hardness or dissolution profile.

Food Industry:

SSF is classified as GRAS (Generally Recognized As Safe) by the FDA and has limited use as an emulsifier and stabilizer in food products. Its use in the food industry is much less common compared to pharmaceutical use.

SECTION 6: ADVANTAGES

• Hydrophilic Structure: More hydrophilic than magnesium stearate; supports drug solubility and does not negatively affect dissolution profile.

• Low Over-lubrication Risk: Lower risk of over-lubrication compared to magnesium stearate; provides wider processing window.

• Tablet Flow Properties: Improves powder flow; ensures homogeneous tablet weight and content uniformity.

• Tablet Hardness: Maintains tablet hardness at appropriate concentrations (typically 0.5-2.0%).

• Disintegration Time: Performs better than magnesium stearate in formulations requiring rapid disintegration.

• Surface Activity: Amphiphilic structure contributes to wetting and dispersion properties.

• Regulatory Compliance: FDA GRAS and pharmacopoeia compliant (USP, EP, JP).

• Effervescent Compatibility: More suitable lubricant than magnesium stearate for effervescent tablet formulations.

SECTION 7: QUALITY STANDARDS AND SPECIFICATIONS

QUALITY STANDARDS EXPLANATION:

Sodium Stearyl Fumarate is manufactured in compliance with international pharmacopoeias including USP (United States Pharmacopeia), EP (European Pharmacopoeia), and JP (Japanese Pharmacopoeia). These standards guarantee the product's purity, physical properties, and microbiological quality.

Pharmaceutical grade SSF is supplied with high purity (≥99.0%) and low loss on drying (≤1.0%). Heavy metal content is limited to ≤20 ppm. By-products such as free fumaric acid and free stearyl alcohol are strictly controlled.

Microbiological quality meets the required standards for pharmaceutical products; total aerobic microbial count ≤1000 CFU/g, yeast and mold ≤100 CFU/g, and pathogenic microorganisms (E. coli, Salmonella, S. aureus, P. aeruginosa) must be negative. For parenteral use, endotoxin levels are limited to ≤5.0 EU/g.

SECTION 8: SAFETY AND TOXICOLOGY

SAFETY AND TOXICOLOGY EXPLANATION:

Sodium Stearyl Fumarate is not classified as a hazardous substance. It has low toxicity (oral LD50 > 2000 mg/kg). It is classified as GRAS (Generally Recognized As Safe) by the FDA. May cause mild skin irritation; dust contact may cause mechanical eye irritation. No mutagenic, carcinogenic or reproductive toxicity classification. Environmental bioaccumulation potential is low. Classified as WGK 1 (slight hazard to water).

Safety Precautions:

• Inhalation: Avoid dust inhalation. Use dust mask (N95/P2).

• Skin Contact: Wash with plenty of water and soap upon skin contact.

• Eye Contact: Rinse with plenty of water for at least 15 minutes upon eye contact.

• Ingestion: Rinse mouth with water. Seek medical attention if large amount is swallowed.

• PPE Recommendations: Dust mask, safety goggles, work gloves.

SECTION 9: TRANSPORT INFORMATION

TRANSPORT INFORMATION EXPLANATION:

Sodium Stearyl Fumarate is not classified as a hazardous substance, therefore no special restrictions apply for road, sea or air transport. UN number, hazard class and packing group are not required. The product should be protected from moisture and transported in appropriate packaging to prevent dust formation. ADR/RID labeling is not required. Not classified as a marine pollutant.

SECTION 10: REGULATORY INFORMATION

REGULATORY INFORMATION EXPLANATION:

Sodium Stearyl Fumarate is registered in all major industrial markets including the EU (REACH), USA (TSCA), Canada (DSL), Australia (AICS), Japan (ENCS), Korea (KECL) and China (IECSC). In Türkiye, it requires mandatory registration under KKDİK (Regulation on Registration, Evaluation, Authorization and Restriction of Chemicals).

It is classified as GRAS (Generally Recognized As Safe) by the FDA. Manufactured in compliance with USP, EP and JP pharmacopoeias. Since the product is not classified as hazardous, no special labeling or packaging requirements apply. Its use as a pharmaceutical excipient is guaranteed by compliance with international pharmacopoeia standards.

SECTION 11: STORAGE AND HANDLING

STORAGE AND HANDLING EXPLANATION:

Sodium Stearyl Fumarate should be stored at 15-30°C in cool, dry and well-ventilated areas. It should be kept in tightly closed containers, preferably in original packaging. Protect from direct sunlight, high temperature, and high humidity. Avoid contact with strong oxidizing agents, strong acids, and high moisture.

Although hygroscopicity is low-medium, protection from moisture is important as moisture adsorption can adversely affect product quality and performance. Under proper storage conditions, shelf life is 24-36 months.

Handling Notes:

• Avoid dust formation (use closed systems, local exhaust ventilation)

• Avoid skin and eye contact (use protective gloves and goggles)

• Avoid dust inhalation (use dust mask or respirator)

• Keep away from high humidity (risk of caking and hydrolysis)

• Typical use concentration in tablet formulations: 0.5-2.0%

SECTION 12: FIRE FIGHTING MEASURES

FIRE FIGHTING MEASURES EXPLANATION:

Sodium Stearyl Fumarate, as an organic compound, is classified as combustible dust. In case of fire, use water spray, CO₂, dry chemical powder or sand for extinguishing. Thermal decomposition may produce CO₂, CO and hydrocarbon fumes. Use self-contained breathing apparatus (SCBA) and full protective clothing during fire fighting. May form explosive mixtures in air as dust cloud (dust explosion risk).

SECTION 13: ACCIDENTAL RELEASE MEASURES

ACCIDENTAL RELEASE MEASURES EXPLANATION:

In case of spillage, appropriate personal protective equipment should be worn (dust mask, safety goggles, protective clothing, gloves). The area should be ventilated and the spill contained to prevent dust spread. Cleaning should be done using vacuum or careful sweeping to prevent dust formation, and the spilled material should be placed in an appropriate disposal container. Environmental release (drains, sewers, water bodies) should be prevented. Waste should be disposed according to local regulations.

SECTION 14: FIRST AID MEASURES

FIRST AID MEASURES EXPLANATION:

Standard first aid measures apply for Sodium Stearyl Fumarate exposure:

• Inhalation: In case of dust inhalation, move the person to fresh air. If coughing or respiratory irritation persists, seek medical attention.

• Skin Contact: Dust should be removed from skin by washing with plenty of water and soap. Remove contaminated clothing. If irritation persists, seek medical attention.

• Eye Contact: Eyes should be rinsed immediately with plenty of water for at least 15 minutes. Remove contact lenses if present. If irritation persists, seek medical attention.

• Ingestion: Rinse mouth with water, drink plenty of water. Do not induce vomiting. If large amount is swallowed, seek medical attention.

SECTION 15: RAW MATERIALS AND DOWNSTREAM PRODUCTS

15.1. Raw Materials (Upstream)

15.2. Downstream Products

SECTION 16: INDUSTRY COMPATIBILITY AND USAGE VOLUMES

SECTION 17: SODIUM STEARYL FUMARATE vs MAGNESIUM STEARATE COMPARISON

COMPARISON EXPLANATION:

Sodium Stearyl Fumarate and Magnesium Stearate are the two most widely used lubricants in pharmaceutical tablet manufacturing. SSF has less negative impact on tablet dissolution profiles due to its more hydrophilic structure compared to magnesium stearate. Over-lubrication risk is lower with SSF, providing a wider processing window. Magnesium stearate, although lower in cost, may present disadvantages in some formulations due to its hydrophobic structure and over-lubrication risk.

SSF is preferred over magnesium stearate especially for APIs with critical solubility, fast disintegrating tablets, and effervescent tablet formulations. Magnesium stearate is more commonly used in general-purpose tablet formulations due to its cost advantage.

SECTION 18: DERIVATIVES AND RELATED COMPOUNDS

SECTION 19: SUMMARY AND CRITICAL NOTES

SUMMARY:

Sodium Stearyl Fumarate (SSF, CAS 4070-80-8) is a lubricant and flow-regulating excipient used in pharmaceutical tablet manufacturing. It is a white or off-white fine powder with a molecular weight of ~390.5 g/mol. The melting point is ~220°C, at which it decomposes. It has low solubility in water; slightly soluble in methanol, insoluble in ethanol and acetone.

Compared to magnesium stearate, its more hydrophilic structure has less negative impact on tablet dissolution profiles and lower over-lubrication risk. It is typically used at 0.5-2.0% concentration. Classified as GRAS by the FDA and compliant with USP, EP, and JP pharmacopoeias.

The primary use is in the pharmaceutical industry; used as a lubricant in direct compression tablets, granulated tablets, fast disintegrating tablets, and effervescent tablet formulations. Also used to improve powder flow in capsule filling. Has low toxicity and is not classified as a hazardous substance. Store in cool, dry, well-ventilated areas at 15-30°C. Shelf life is 24-36 months.

Basic Properties:

Main Application Areas:

Key Safety Points:

• LOW TOXICITY: No hazardous substance classification; LD50 > 2000 mg/kg

• GRAS: Classified as Generally Recognized As Safe by FDA

• IRRITANT: Dust may cause respiratory, skin and eye irritation; use appropriate PPE

• STORAGE: 15-30°C, cool, dry, tightly closed; protect from direct sunlight and moisture

• PPE RECOMMENDED: Dust mask (N95/P2), safety goggles, work gloves

• INCOMPATIBLE: Strong oxidizing agents, strong acids, high moisture

• SHELF LIFE: 24-36 months (under proper storage)

CRITICAL NOTES:

1. Hydrophilic Structure: Sodium Stearyl Fumarate is a more hydrophilic lubricant compared to magnesium stearate. This property has less negative impact on tablet dissolution profiles and provides a significant advantage especially in drug formulations with critical solubility.

2. Low Over-lubrication Risk: SSF has lower over-lubrication risk compared to magnesium stearate. This provides a wider processing window and greater flexibility during formulation development.

3. Usage Rate: Typically used at 0.5-2.0% concentration. Within this range, optimal lubrication and flow properties are achieved without negatively affecting tablet hardness and disintegration time.

4. Pharmacopoeia Compliance: Compliant with USP, EP and JP pharmacopoeias. Pharmaceutical grade products are supplied with high purity (≥99.0%) and low loss on drying (≤1.0%).

5. Application: Can be safely used in direct compression tablets, granulated tablets, fast disintegrating tablets (ODT), effervescent tablets, and capsule formulations.

6. Magnesium Stearate Alternative: SSF should be preferred in formulations where magnesium stearate shows negative effects on dissolution profile or where over-lubrication risk is high.

7. Storage: The product should be stored in cool, dry, well-ventilated areas, protected from direct sunlight and moisture. Keep in tightly closed containers.

8. Hydrolysis Sensitivity: May undergo slow hydrolysis in the presence of moisture. Therefore, protection from moisture is important for shelf life and product quality.

IMPORTANT DISCLAIMER: This Technical Data Sheet (TDS) is for informational purposes only and is prepared based on available technical data. The information provided is believed to be accurate. However, the user is solely responsible for determining the product's suitability for their specific applications and for complying with all applicable local, national and international regulations and safety requirements. For complete safety, storage, handling, transport, waste and regulatory compliance information, please refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Users are obligated to test the product in their own processes and applications. All occupational health and safety rules must be observed when working with Sodium Stearyl Fumarate.