In this paper, the optimization of a generic function of a lipstick manufacturing process is discussed. Traditionally, the quality of lipsticks has been measured by objective quality characteristics such as appearance. Sensory tests, which are not recommended in quality engineering, had been used to evaluate such quality characteristics. That is because these quality characteristics are not stable due to the changes of environmental conditions such as between-lot variability and seasonal variation. When such quality problems occurred, manufacturing conditions were adjusted from time to time, which is known as fire fighting or “mole beating” in Japanese. Among those objective quality characteristics, the ones such as scratches, color uniformity or breaking during usage are manufacturing related. As a generic function, the stress/strain relationship was investigated and the results showed that the relationship has satisfied Hook's Law with a good improvement.

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In Japan, the term mizumizushii is used to express beauty. This term mizumizushii is an adjective involving factors for a variety of “beauties full of the feeling of vitality” such as youthful, fresh, watery, dewy and the like. The exact choice of words depends on the circumstances. Mizumizushii-looking skin represents the skin that looks wet with the moisture contained in it and that has a good gloss. However, according to our research carried out using a Corneometer, almost no relationship was found between skin actually including a large amount of moisture in the stratum corneum and mizumizushii-looking skin. We elucidated the “apparently mizumizushii-looking skin, ” and tried to develop makeup products having the function of making the skin look mizumizushii, which is to be one of the factors of beauty. For this purpose, what makes skin mizumizushii-looking or not had to be defined. Hence, sensory evaluations on 100 women were performed. As a result, these panelists could be classified into two groups of those having mizumizushii-looking skin (25 women) and those having the skin without a mizumizushii look (75 women). Further, it was revealed that the skin without a mizumizushii look could be classified into two groups of dry-looking skin and excessively oily-looking skin. We succeeded in qualitatively classifying the appearance of the skin of these three groups through using a value for optical properties analyzed under specified conditions. Moreover, as a result of investigation of the grounds for possible qualitative classification of these groups with the value for optical properties of the skin, an evident relationship was clarified with the surface morphology (homogeneity on a μm scale). From the findings of the optical properties of the mizumizushii-looking skin, we designed a makeup film incorporating a function for the mizumizushii look, leading to the development of a foundation.

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Two basic functions of emulsion-based cosmetic products are moisturization and occlusion, which are markedly affected by the ratio of hydrophilic to lipophilic parts in the emulsions. However, due to their conflicting requirements, it is difficult to simultaneously improve both functions. Therefore, we developed new emulsion that has simultaneously higher moisturizing and occlusive functions than those of polyoxyethelene-type emulsions, by using polyglycerin-type surfactants, cetyl alcohol, polyglycerin-13-polyoxybutylene-14-stearyl ether and the D-phase emulsification method, because of dispersing a large quantity of water into the lipophilic part of the applied emulsion film and of strengthening the hydrophilic part of the emulsion film. We confirmed through microscopic study with a laser microscope that in polyoxyethelene-type emulsions, droplets disappear quickly after the film is formed and dried, whereas in our experimental emulsions, the droplets' shape is evenly retained. Furthermore, after one month of continuous use, stratum corneum removal and corneocyte arrangement also improved significantly.

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Liquid plasters, dissolved pyroxylin (nitrate ester of cellulose) in organic solvents, are classified as new quasi drugs or OTC drugs, which are used for the purpose of dressing damage and disinfection. The defects are the odor of the organic solvents, strong irritation against damaged skin, difficulty at the removal of formed film, and poor release of active ingredients from plasters. A thermosensitive polymer was prepared by copolymerization of N-isopropyl acrylamide and n-butyl methacrylate. The application of the thermosensitive polymer to liquid plaster improved the above defects, and showed formation of appropriate firm and effective antimicrobial activities.

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In this study, it was shown that sodium dextran sulfate (DS), which is used as an antihyperlipoproteinemic and is clinically known for the improvement of the blood flow, accelerated nitric oxide (NO) synthesis in the normal human epidermal keratinocytes. Currently, the free radical NO is known to be an important mediator in various physiological and pathophysiological processes of the skin, such as regulation of blood flow. The result suggests that DS might exert improvement on the blood flow by the acceleration of NO synthesis. The evaluation in the human body test showed that DS effectively reduced and prevented the swelling of the lower leg. Consequently, it is reasonable to suggest that DS could penetrate into the epidermis and enhance NO synthesis, and NO released from the epidermal keratinocytes could promote the blood flow in the microvasculature and reduce the swelling of the lower leg.

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