Eye cosmetics, especially mascara and eyeliner, are most important items in the category of point make-up products. These cosmetics are useful for acheiving an individual look with make-up. Therefore various studies have been done for that purpose. Recently, besides the color of the products, young consumers have demanded special functions, for example, curl or longlash effects of eyelashes. This paper reports the utility and recent technological changes in these products based on several studies, patents and trends of the market.

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Many lipstick products have been developed and marketed. Lipstick, used by almost all Japanese women, is the most important cosmetic product. In this paper, the utility of make-up effect and treatment effect of lipstick products as well as the hardness property of oil-wax gel are described.

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A highly viscous and translucent gel formed in a water/partially hydrophilic crosslinked silicone (PHCS)/oil system. It is a high-internal-phase-ratio W/O type gel emulsion. The region of the gel emulsion was wide in this system when compared with the region of the gel emulsion prepared by conventional hydrocarbon type surfactant in the same system. The size of water droplets in the gel emulsion prepared by PHCS was very large. The gel emulsion was stable in a wide temperature range. The viscosity of the gel emulsion showed thixotropic character. A fluorescent probe study showed that the state of hydrophilic and hydrophobic moiety of PHCS remained unchanged with an increase in water content. The reason for the stability is supposed to be based on the following facts: 1) The PHCS has little change of solubility to the water and oil for temperature change because of its polysiloxane chain structure. 2) The silicone chain shows high hydrophobicity. 3) The molecular weight of PHCS is very large. Hence, the water droplets in the gel emulsion do not coagulate and the gel emulsion is stable in a wide temperature range.

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The recent development of a confocal microscopic (CM) technique for skin imaging enabled the examination of the internal structure of human skin at a cellular level. We used CM (Vivascope 1000, Lucid Co., USA) to investigate the structural and morphological changes with skin depth in a normal volunteer as well as the epidermal thickness and the change of epidermal-dermal junctional undulation in experimentally induced rough skin by SDS (sodium dodecyl sulfate) or tape-stripping, We also examined those of change in sun-exposed and sun-protected areas. In order to investigate the epidermal-dermal undulation we reconstructed the 3D structure of skin to cumulate the images of horizontal section and finally extracted the undulation from the vertical section images using the Snakes method. The morphology of keratinocyte changed drastically with skin depth. The average projected area in basal cells was about 100μm² and that at the surface of stratum corneum was about 1200μm². These results show that the keratinocytes become more than 10 times flatter at the skin surface during differentiation and keratinization. Both treatments of SDS and tape-stripping made the epidermis thicker (more than two times compared with control) and these effects continued until 25 days after treatment. On the other hand, the skin surface topolography returned almost to its initial state after 25 days. Our results suggest that the superficial recovery of stratum eorneum from external stimuli is comparatively fast but the effeet on the internal condition of the skin lasts longer. Epidermal thickness and the undulation of dermal papillae are quite different in sun-exposed (cheeks, the dorsal forearm) and sun-protected (the volar upperarm) area. The epidermis in the cheek site is thicker than in the upperarm and the epidermal-dermal junction is clearly undulated compared with other areas. From there results it was concluded that the in vivo confocal microscope is a useful instrument to examine the internal structure of human skin non-invasively and to evaluate the effects of cosmeceutical ingredients on the skin.

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A thick or stiff feeling of hair is thought to be due to a complex combination of several physical properties including the bending stress, the torsional stress, and the friction among hair fibers. Rigidity of hair is one of these basic factors. Rigidity as Young's modulus from a material dynamics viewpoint was evaluated accurately by measuring a minor and a major axis of hair. An experimental instrument equipped with laser beam emission for hair diameter measurements has been developed to estimate the minor and the major axis of hair, A two-phase structure model which has different Young's modulus (cuticle and cortex) was assumed. Evaluations of Young's modulus of an intact hair and a delaminated hair from which the cuticle was removed by physical stripping were carried out. The results showed that the cuticle Young's modulus of normal hair was approximately four times than that of the cortex. The contribution of the cuticle to the bending stress of whole hair was also evaluated by the minor axis, the major axis, and the thickness of the cuticle. Since the contribution of the cuticle to the bending stress of whole hair was up to 60%, it was concluded that the cuticle could play an important role in the thick or stiff feeling of hair.

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