A moisturizer that maintains or increases the water content of the stratum corneum is an important cosmetic ingredient in order to prevent skin trouble. There are various types of moisturizer for cosmetics, from low-molecular-weight moisturizers such as NMF or polyols to bio-derived polymers such as hyaluronic acid. In general, a low-molecular-type moisturizer has high moisture absorption ability; however, it is possible for the texture to deteriorate when the content of moisturizer is high to enhance moisturizing efficacy. We designed polyoxybutylene（3）polyoxyethylene（ 8）polyoxypropylene（5）glyceryl ether as a water-soluble moisturizing oil which has high spreadability but no stickiness. We have found that it has a penetration control effect for active components. In addition, we have focused on a phospholipid polymer bearing phosphorylcholine groups in the polymer side chain as a material that improves both the water-retention effect and water-transpiration-suppressing effect. We also have found that it could protect skin from various environmental stresses such as air pollutants, irritants, fungi, and ultraviolet rays.

Most hair coloring involves oxidative polymerization of oxidation dye intermediates (precursor and coupler) with an oxidizing agent. A dyeing method for simultaneously carrying out this reaction and decomposition reaction of melanin in the hair by an oxidizing agent is widely used with high convenience. However, it is known that oxidizing agents damage the cuticles and cortex constituting the hair. In addition, allergies due to oxidative dye intermediates have been reported. In this study, we synthesized oxidative polymerization dye (diphenyl indo dye) with oxidation dye intermediates during oxidation in advance before use for dyeing hair. The dyeing of the hair was carried out with a model cream formulated with the oxidation dye. Then, we confirmed the functionality of that hair dyeing method using oxidation dyes added to the hair. In addition to sensory evaluation based on the appearance and feel of the hair, the evaluation of the functionality of the hair was carried out by protein dissolution measurement from the hair, luster measurement, friction measurement, compression measurement and the like. As a result, it became clear that hair coloring agents containing oxidation dyes make it possible to dye without damaging the hair, giving the hair a glossy feeling, smoothness and flexibility. Since the hair dyeing method using oxidation dyes imparts new functionality to the hair, development of a further hair dye making use of its properties is expected.

Intercellular lipid (ICLs) content in the stratum corneum is an important determinant of the barrier and water-holding functions of skin. Ceramides are major components of ICLs and their supplementation in skin may provide improved barrier function. Thus, various emulsification technologies have been developed to enhance their penetration into skin. However, ceramides easily crystallize, making such penetration at a high quantity difficult. We developed a liquid crystal product for assisting with a high level of penetration of the pseudo-ceramide (sphingolipid E (SLE)) into the stratum corneum. We focused on cholesteryl alkenyl succinate (CHAS), which has a structure composed of cholesterol (CHOL) and fatty acids, and prepared multi-lamellar vesicles consisting of SLE, CHAS, phytosphingosine, and CHOL. The vesicles formed a liquid crystal structure and maintained that structure even after drying. As compared to conventional products, the amount of penetrated SLE was twice that with use of the liquid crystal vesicle formulation. We report here successful development of a liquid crystal product for a substantial increase of intradermal penetration by SLE.

Damage to the cuticle layer makes it more difficult to smooth comb and style. In particular, the bleaching treatment not only degrades the main substrate, melanin, but also increases the friction of the hair surface due to lift-up of the cuticle. In this study, we investigated the mechanism of cuticle damage by bleaching treatment for the purpose of cuticle care. As a result, it was recognized that the bimetallic effect caused by ionization of the side-chain carboxyl group of proteins promotes lift-up of the cuticle. We proposed the term “Cuticle Bi-metallicity” for this mechanism and found glutamic acid as its modulation factor. Furthermore, it was revealed by a novel visualization and quantification system that glutamic acid treatment significantly decreased cuticle removal because of combing. These results suggest that glutamic acid modulates the cuticle bimetallicity by repairing the ionization of carboxyl groups in the cuticle layer caused by bleaching treatment.

The main trouble of the lips is “dryness and chapping”, but the trouble of the lips changes with aging. That is, these troubles are reduced after peaking in subjects' 30s, and troubles concerning color and shape increase with aging. However, there are few reports on age-related changes in lip shape, and it is not clear how it changes. We focused not only on the red part which is usually called the lips, but also on the surrounding white lips which are thought to have a great influence on the aged impression, and examined them by measuring from front and side photographic images. As a result, it became clear that the white lips part became longer with aging and became more rounded. Furthermore, it quantitatively clarified that the length of the red lips part became thin and the width became wider, and that the swelling of the lower lip as seen from the side decreased. It also became clear that these many shape changes occurred remarkably at the age of over four decades. We also confirmed that similar age-related changes occurred in the same subjects, and also verified that it was due to age-related changes rather than individual differences.