Application of L-threonine in cleaning cosmetics

L-Threonine is an important amino acid with various applications in cleansing cosmetics. Its primary functions are as follows:  

1. Cleansing and Dirt Removal Assistance  

Enhancing Surfactant Performance: L-Threonine can interact synergistically with commonly used surfactants in cleansing cosmetics. For example, when combined with anionic surfactants such as sodium dodecyl sulfate (SDS), it can adjust surface tension and micelle formation capacity, allowing surfactants to perform better in removing dirt, oil, and makeup residues from the skin.  

Improving Foam Properties: L-Threonine helps stabilize and enhance the foam produced by cleansing products. In facial cleansers and body washes, it creates finer, richer, and longer-lasting foam. A dense foam not only improves the sensory experience during cleansing but also enhances cleaning efficiency by evenly covering the skin, increasing dirt adsorption and removal.  

2. Moisturization and Skin Care  

Retaining Skin Moisture: L-Threonine possesses moisturizing properties, forming a thin hydration film on the skin’s surface to reduce moisture loss. This helps prevent dryness and tightness after cleansing, which is crucial for maintaining skin barrier function and physiological balance. It is particularly beneficial for dry and sensitive skin, as it minimizes irritation caused by cleansing products.  

Promoting Skin Repair: L-Threonine participates in skin cell metabolism, providing nutrients that support cell renewal and repair. During cleansing, the skin may experience mild damage, and L-Threonine helps accelerate self-repair, keeping the skin in a healthy state.  

3. pH Regulation and Mildness Enhancement  

Adjusting pH Balance: L-Threonine can function as a pH regulator, helping to balance the pH of cleansing cosmetics to be closer to the skin’s natural physiological pH, which is generally slightly acidic. Maintaining an appropriate pH level supports the skin’s acid-base balance, reducing irritation and preventing disruption of the skin barrier, ultimately improving the gentleness and safety of the cleansing product.  

Reducing Irritation: The inclusion of L-Threonine makes cleansing formulas milder, reducing potential skin irritation. This makes it suitable for all skin types, especially sensitive skin. It also helps alleviate irritation that may be caused by other ingredients, lowering the risk of allergic reactions or discomfort.  

4. Antibacterial and Preservative-Boosting Effects  

Antibacterial Properties: L-Threonine exhibits antibacterial activity, helping to inhibit the growth of certain bacteria, such as Staphylococcus aureus. In cleansing cosmetics, it assists in reducing bacterial presence on the skin, preventing bacterial overgrowth that may lead to skin issues like acne and breakouts, thus enhancing the antibacterial efficacy of the product.  

Enhancing Preservative Efficiency: L-Threonine can also work synergistically with preservatives, boosting their effectiveness. It modifies bacterial cell membrane permeability, allowing preservatives to penetrate bacterial cells more efficiently. This enhances the ability of preservatives to suppress bacteria, mold, and yeast, thereby prolonging the shelf life of cleansing cosmetics.