Lauroyl Lysine

Lauroyl Lysine – Multifunctional Amino Acid Derivative for Skin and Hair Care

Basic Information

• CAS Number: 52315-75-0

• INCI Name: Lauroyl Lysine

• Molecular Formula: C₁₈H₃₆N₂O₃

• Molecular Weight: 328.49 g/mol

• Appearance: White to off-white solid powder

• Synonyms: N6-Lauroyl-L-lysine, N6-(1-Oxododecyl)-L-lysine

• EINECS/ELINCS: 257-843-4

Chemical Structure and Synthesis
Lauroyl lysine is an N-acylated derivative of the essential amino acid L-lysine, formed by the amidation of the ε-amino group of lysine with lauric acid (dodecanoic acid). The molecule can be represented as:
H₂N–CH(COOH)–(CH₂)₄–NH–CO–(CH₂)₁₀–CH₃
This structure combines a hydrophilic amino acid head (lysine) with a lipophilic fatty acid tail (lauryl), resulting in a highly amphiphilic molecule. The synthesis involves the reaction of lysine with lauroyl chloride or an activated lauric acid derivative in the presence of a base to form a stable amide bond.

Physicochemical Properties

• Amphiphilic nature: Balances hydrophilic and lipophilic properties, enabling effective interaction with both aqueous and oil phases.

• Silky feel: Imparts a smooth, lubricious, non-greasy texture to skin and hair.

• Hydrophobicity: The lauryl chain provides water-repellent properties, enhancing product stability and wear.

• Biocompatibility: Derived from natural amino acid and fatty acid sources, well-tolerated by skin.

• Stability: Chemically stable under normal storage conditions; maintains activity in cosmetic formulations.

• Solubility: Soluble in DMSO; limited water solubility.

Applications
Lauroyl lysine is a versatile ingredient widely used across the cosmetics and personal care industry:

• Skin care: Creams, lotions, moisturizers, sunscreens – provides skin conditioning, softening, and a silky feel.

• Hair care: Shampoos, conditioners, serums – improves smoothness, shine, and manageability.

• Color cosmetics: Foundations, powders, lipsticks, eye makeup – enhances pigment dispersion, adherence, and long-lasting wear.

• Surface treatment: Used as a surface treatment for pigments to improve stability and durability.

• Emulsion stabilization: Acts as a co-emulsifier and texture enhancer, improving product consistency and stability.

Key Benefits

• Provides excellent skin and hair conditioning properties.

• Imparts a silky, smooth, non-greasy feel.

• Enhances pigment adherence and long-lasting wear in makeup.

• Stabilizes emulsions and improves product texture.

• Biocompatible and well-tolerated by skin.

• Suitable for leave-on and rinse-off formulations.

• Plant-derived, non-animal origin, and biodegradable options available.

Safety and Regulatory
Lauroyl lysine is considered safe for use in cosmetics and personal care products at current usage concentrations. It is not a skin sensitizer, with no significant irritation reported at typical use levels. The Cosmetic Ingredient Review (CIR) Expert Panel has concluded that amino acid alkyl amides, including lauroyl lysine, are safe in cosmetic formulations when formulated to be non-irritating.

Recommended Use
Typical usage levels range from 0.5–5.0% depending on the desired effect and product type. Can be incorporated into the oil phase or added as a powder directly to formulations. For optimal performance, disperse with moderate mixing and heat if necessary.

Handling and Storage

• Store in a cool, dry place, away from direct sunlight and moisture.

• Keep containers tightly sealed to prevent contamination.

• Use appropriate personal protective equipment (gloves, safety goggles) when handling.

• Shelf life: typically 24 months under recommended storage conditions.

Quality Assurance
Each batch is tested for purity, heavy metals, and microbial contamination to ensure compliance with cosmetic-grade standards.