The skin concentration of topically applied cosmetic active ingredients is very important for evaluating cosmetics. However, a large variation is often observed in finite dose experiments due to the evaporation of volatile components in the formulation and difficulty in applying the formulations uniformly. In addition, steady-state skin concentration could not be attained even after several hours of application. In our previous report, three formulations, lotion, milk, and cream, and the mixture of these formulations containing isopropyl methyl phenol (IPMP) as a model ingredient were applied to excised human skin with infinite dose (ten to one hundred higher application dose against actual amount of application of personal cosmetic products) in eight research facilities. As the result, the formulation with the highest skin permeation also showed the highest skin concentration. In the present study, the same experiment with the previous report was conducted using a hydrophilic compound, caffeine (CAF). The skin permeation of CAF increased with a decrease in skin electrical resistivity, whereas no relationship was observed in IPMP. Since a large variation of skin permeation of CAF was observed in low skin resistance (<10 kΩcm2), the skin having larger than 10 kΩcm2 skin resistance was used in three facilities in the additional test. The obtained results were consistent among the facilities in the following order of skin permeation (lotion>milk) and corresponded with that of the skin concentration. These results suggest that skin resistance should be considered when a hydrophilic compound is applied in in vitro skin permeation test. In addition, the present and the previous results show that topical formulations with in vitro skin permeation experiment with an infinite dose could identify the formulation which exhibited the highest steady-state skin concentration of cosmetic active ingredients.
Menopausal women show some physical and mental problems. It is known that the disorder is caused by the rapid decrease of estrogen and testosterone. Hormone replacement therapy has been used to treat menopausal symptoms, but side effects have also been reported. Therefore, there is a need for alternative medicine with few side effects that replace hormone replacement therapy. Based on our research, pheromones increase endogenous hormone secretion in humans. In this paper, we outline not only the method of searching for pheromone equivalents among aroma components derived from plants, but also the possibility that these pheromone equivalents will be alternative medicine for menopausal disorders. In addition, we outline the concept of functional aroma we have proposed recently.
In the near future, just as humans interact in language, dialogue enables us to understand each other’s intentions and desires, even between humans and home appliances. We discuss the possibility of such a future society while introducing the robot research of the speaker.
Hair care products include shampoo, conditioner, treatment, hairstyling product, perm agent, coloring agent, and hair growing agent. The products other than shampoo and hair growing agent are used for scalp hair shaft, which is a dead part. Therefore, unlike skin care products, it is characteristic for hair care products that some of them act with a chemical reaction, like permanent wave lotions and oxidation hair dyes. In this article, I explain hair care products except in-bath products (shampoo, conditioner, and treatment) with a focus on their functions, product types, purposes, ingredients, and usages. Hairstyling can be performed by rearranging hydrogen bonds in hair. In other cases, hairstyles are made by fixing hair fibers with fixative ingredients. Hairstyling products assisting hairstyling or fixing hairstyles include hair sprays, hair water or lotions, hair foams, hair creams or milks, gels, liquids, tonics, oils, waxes, etc. The characteristics of their forms and components are explained. Perm agent is intended to change hair shape permanently by cleavage and recombination of disulfide bonds in the hair. In addition to the perm agent of quasi-drug from the past, there has been extending recently curling agents of the cosmetic category, of which curling mechanism is based on the reduction and oxidation of disulfide bonds, same as quasi-drugs. As for hair coloring agent, there are also quasi-drugs and cosmetic products. In the quasi-drug category, there are oxidation hair dyes and bleaching agents. There are semi-permanent hair color and temporary hair color in cosmetic products. Their coloring mechanisms and including components are described. As for hair growing agents, many effective ingredients have been proposed in accordance with the mechanism of thinning hair. I explain briefly products in the categories of medicine and quasi-drug.
It is well known that fragrances influence our senses. Fragrances used in cosmetic products are no exception. Not only masking the odor of the product base, they give various impressions such as freshness, comfortableness and newness, and provide higher added value to products. In this report, we describe the fragrance development with a focus on raw materials, functional materials, and creation by perfumers. In addition, it is necessary to understand the regulations and environment issues related to fragrances and cosmetics.