Abstract
We studied the application of malic acid monolaurylamide (MAA) for a new skin care cleansing agent. MAA neutralized by potassium hydroxide (MAAK) showed an excellent fresh feeling after washing the skin because of quick Ca-salt formation while rinsing out. The order of the skin tightness after washing was potassium laurate>sodium polyoxyethylene lauryl ether sulfate (3E.O.)>potassium lauroylglutamate>potassium N-lauroyl-N-methyl-β-alaninate≥MAAK. The amounts of MAAK residue on the surface and in the deeper portion of the skin were found to be almost 1/10 of those of potassium laurate. In addition, MAAK had selective cleaning ability and showed to minimize the release of the Natural Moisturizing Factor from the skin compared to potassium laurate. The characteristics of MAAK are also significant in mixed surfactant systems. For example, fresh feeling in rinsing out process was maintained even though MAAK was mixed with another surfactant, which has a slimy feeling, such as lauryl dimethylaminoacetic acid betaine. Also, when MAAK was added to potassium laurate, potassium laurate residue on the skin was decreased and the skin tightness became low after washing. Therefore, MAAK is concluded to be a very valuable surfactant for the skin washing agent.
