N‐Palmitoyl‐4‐Hydroxy‐L‐Proline Palmityl Ester: A Pseudoceramide that Provides Efficient Skin Barrier Repair and Protection

Abstract

Ceramides are the main constituents of the epidermal permeability barrier, and it has been demonstrated that the application of ceramide enriched creams promotes epidermal barrier repair. However, nature‐identical ceramides are extremely expensive and difficult to formulate. We therefore developed a new pseudoceramide, N‐palmitoyl‐4‐hydroxy‐l‐proline palmityl ester (BIO391). Due to its low melting point of £60°C the pseudoceramide BIO391 can easily be incorporated into cosmetic formulations. In addition, it is very safe for use in cosmetics.The efficacy of the pseudoceramide BIO391 was investigated in vivo in a model for detergent‐induced barrier disruption. Trans‐epidermal water loss, redness, and skin hydration were recorded before and after barrier disruption as well as during the subsequent 9‐day treatment with the test products.Barrier repair of skin treated with the pseudoceramide BIO391 was accomplished earlier than that of untreated and vehicle treated skin. Optimum barrier repair was achieved with 1.0% pseudoceramide BIO391 and optimum erythema reduction with 0.5% pseudoceramide BIO391. The optimum dosage could be reduced to 0.1% pseudo‐ceramide by synergistic combination with 0.1% (‐)‐a‐bisabolol. In addition, the pseudoceramide BIO391 proved to be as effective as nature‐identical ceramides 2 and 3. In summary, N‐palmitoyl‐4‐hydroxy‐l‐proline palmityl ester is a highly efficient barrier repair agent with efficacy equivalent to that of nature‐identical ceramides, and it has excellent formulation properties.