Skin problems caused by cosmetics include not only irritant and allergic contact dermatitis, but also leukoderma caused by application of active brightening materials and immediate type wheat allergy due to hydrolyzed wheat protein. These skin problems have characteristic clinical symptoms and causative components and require specific testing methods. This article describes the skin problems caused by cosmetics for each site where symptoms are induced. On the scalp and face, allergic contact dermatitis is induced by ingredients present in cosmetics and daily hygiene products and hair coloring agents, especially preservatives such as isothiazolinones. Allergic contact dermatitis on the face also occurs due to chemicals used in eyelash extensions and components in lipstick. In Japan, the number of cases of leukoderma caused by ingredients contained in whitening cosmetics has rapidly increased and has become a social problem. Skin problems caused by cosmetics involve not only delayed allergic reactions but also immediate type reactions. After sensitization of the skin to the protein component contained in cosmetics, ingestion of foods containing the protein induces immediate type allergy. We have already experienced about the case of anaphylactic shock induced in immediate type allergy by hydrolyzed wheat protein or cochineal. The most useful test for identifying allergic contact dermatitis is the patch test. Repeated open application test (ROAT) using the cosmetic product is also a useful skin test. Additionally, the skin prick test is performed for immediate allergy. The Skin Safety Case Information Network (SSCI-Net) was established to quickly collect cases of contact dermatitis caused by cosmetics and daily use products, and to share the information with organizations such as cosmetic companies, relevant government agencies, and academia. It is hoped that skin troubles caused by cosmetics will be minimized through the efforts of the SSCI-Net.
Cosmetic companies assure their cosmetic products based on national regulations and their own internal rules. The safety of cosmetic products consists of raw material safety and practical usage safety. Regarding the safety assessment of raw materials, local and systemic toxicological endpoints are based on market histories and existing data. When existing information is insufficient, safety tests have to be conducted. Many companies have abolished animal testing on cosmetics and raw materials. However, there are significant limitations in non-animal testing alternatives currently. After the safety of a raw material is assured, its safety in product form must also be assessed. When considering safety concerns regarding practical usage, all the influencing factors, such as age, sex, and sensitivity of the target population, have to be taken into account. Likewise, the period, frequency, and topical area of use must be taken into consideration. If the products show any safety concerns, product form tests should be conducted to further ensure their safety. When companies launch their products following safety assurance procedures, they should conduct post market surveys to monitor for any adverse events. If any such events occur, the company should evaluate the contents and take suitable actions. Further to this, in 2014, the Japanese government imposed the rule on companies that they must report each case of any severe adverse events related to cosmetic use. The safety of cosmetics has been well maintained by both the regulatory system and cosmetic company care and due diligence. However, more and more innovative products are being developed, with some causing severe and broad adverse events. Safety assessors should train themselves to keep their skills and knowledge up to date and companies should enhance their survey system to catch safety problems earlier.
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.
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.
Makeup cosmetics have been used in ancient times for the purpose of religious acts or expression of user’s authorities. The meaning of makeup changes with the times, and nowadays it is mainly used for the expression of personal beauty and tidy appearance. The main function of the makeup products are visual effects such as hiding of skin troubles, modifying the skin color and texture, and making users look more attractive with color and brilliance. In addition, recent makeup products also offer protective function such as moisturization or UV protection. Furthermore, research about the psychological effects by using makeup products is also in progress such as gaining confidence, satisfaction and sociality. There are various makeup products with different application area, and their usage method and required finishing state differ depending on each product. Therefore, in order to use makeup products safely and effectively, it is important to understand the composition of each product and usage method including the package and the applicator. In this article, I explain the formulation composition and several essential raw materials of each makeup product, and outline the molding technology and usage.
Skin wrinkles are worldwide, major concern for beauty. Many studies report the mechanisms of wrinkle formation, including intrinsic and extrinsic aging-relating changes of skin structure/function. Since fine wrinkles, which are observed at epidermis, are known to be formed by dryness of skin, moisturizing is one of the best options for prevention/improvement of fine wrinkles. On the other hand, deeper wrinkles show structural alteration of dermis. The changes of quality and/or quantity of dermal extracellular matrix, such as collagen, elastic fiber and hyaluronic acid, are reported in aged skin. In this paper, we summarize how fine- and deep wrinkles are formed based on various studies, and introduce established treatments for anti-wrinkles.
In recent years, it is reported that UV light affect DNA damage, skin cancer and photo-aging such as age-spots and wrinkle. Along with the increasing awareness to protect the skin from UV light in these days, multi-functionalization is required to sunscreen not only for pool, sea and sports use, but also for daily use. Functions of sunscreen are needed to have high UV protection efficacy and less burden use feeling on the skin such as transparency after applying, moisturizing effect and comfortable feeling. In addition to that, it is reported that friction resistant function is important from the view point of actual consumer dairy life. This article reviews sunscreen formulations with high UVA protection efficacy and moisturizing of W/O technology by using plate like zinc oxide, and even protection film O/W technology by using α-gel capsule of UV absorbers. Furthermore, it also reviews UV protect evaluation method of sunscreen and sunscreen effects for photodermatosis, skin cancer and photo-aging such as age-spot, wrinkle and skin color evenness.
In Japan, there are values that prefer the state where the skin is white and has no spots or dullness. Therefore, spots and freckles are becoming one of the skin troubles for many consumers. The term “skin whitening” is used as a term referring to skin care for skin troubles such as spots and freckles. Products used for skin whitening purposes, so-called whitening products, generally refer to quasi-drugs containing skin whitening active ingredients. Various mechanisms of action for skin whitening have been elucidated so far, and various skin whitening active ingredients have been developed accordingly. In this article, the functional mechanism of skin whitening active ingredients blended in skin whitening quasi-drugs and the effects on human skin were outlined.
Cosmetics are used to help the skin’s native function work normally with the aim of keeping and recovering healthy, beautiful skin and hair. Cosmetics have a variety of roles; their basic purposes include washing, wiping clean, and anti-dryness, anti-ultraviolet, antioxidation and stimulation functions. The purpose of bodily cleansing is to remove dirt on skin and hair and keep a body hygienic. Cosmetics can be classified in various ways, such as by their purpose and form, and body cleansing agents can be categorized by the body parts to which they are applied, such as cleansing agents for skin, the body, and hair. Skin cleansing agents, which are used to wash facial skin, remove metabolites produced by physiological actions of the skin, such as sebum, stratum corneum scales, oxidative degradation agents of sebum, sweat residue, dirt in the air, microorganisms, and makeup residue from the skin’s surface. Like skin cleansing agents, body cleansing agents are used to wash a large region of the body. Hair cleansing agents remove dirt on the scalp and hair and keep them clean. Although the kinds of dirt on the scalp and hair are similar to those on the skin, residues of hair care agents are also dirt to be removed. What is needed in common for these cleansing agents includes detergency, low stimulative effect on the skin, and foaming property, and these attributes mainly depend on the properties of surfactants. The evolution of cleansing agents is due largely to the evolution of surfactants. Looking back on the historical background of cleansing agents and the basis of cleansing, this article describes the kinds and ingredients of cleansing agents and the effects of cleansing agents by classifying the agents by the body parts they wash and focusing on surfactants.
The stratum corneum (SC) is the outermost layer of the skin and plays important roles in sustaining physiological activities. One of the roles of the SC is in the maintenance of skin moisture. The decrease in water content in the SC, which is a condition called dry skin, leads to a mildly rough skin and desquamation. Natural moisturizing factor (NMF) and intercellular lipids are essential for skin moisturization. NMF, which is composed of amino acids, pyrrolidone carboxylic acid, lactic acid, urea, and mineral ions, can hold water molecules in the SC. Intercellular lipids consisting of ceramides, cholesterol, cholesterol esters, and free fatty acids can prevent the evaporation of water molecules from the body, which is a barrier function. Moisturizers are broadly categorized into two types, humectants and emollients. Humectants such as amino acids, polyols, hyaluronan, and its derivatives moisturize the SC similarly to NMF. Emollients such as ceramides and oils are effective for improving the barrier function. Moisturizing products contain these moisturizers in various formulations. The moisturizing effect of products differs depending on the type of formulation. An adequate amount of a moisturizer in a product is important for providing both the moisturizing effect and the good texture of use, which affects continued use, because a large moisturizer amount impairs the texture of use.
Cosmetics and medicated cosmetics are recognized as a necessity of daily life to increase the quality of life, and are used to maintain health and increase beauty. Cosmetics and medicated cosmetics are mainly regulated by The Law on Securing Quality, Efficacy and Safety of Products Including Pharmaceuticals and Medical devices. The main purpose of the Law is to improve public health, and to achieve this, securement of the quality, efficacy, and safety of cosmetics etc. is required. To fulfill the purpose, it is necessary to understand the regulation for cosmetics and medicated cosmetics accurately and to follow the Law properly. In this report, the definition of cosmetics and medicated cosmetics, regulations on ingredients and efficacy-effects, and regulations for selling cosmetics etc. are described.
Cosmetics that are used daily to keep our skin healthy and to make it look attractive, are available in many types where ingredients comprising them vary depending on the formulation in which they are contained. The infant stage of modern Japanese cosmetic history just after the Meiji Restoration (1868) saw many novel products appearing on the market one after another due to demands and changes in consumer perceptions, new findings in dermatology and the birth of new ingredients and development of formulation technologies, where up until then, only limited items e.g., facial cleansers and skin lotions for skincare and face powders, rouge and eyebrow pencils for makeup were commercially available. The myriad of cosmetic formulations available today are the fruits of the technology development history to meet consumer demands. With the recent advent of consumers demanding both efficacy and safety concurrently, cosmetic research and development too has entered a new era, and changes are envisaged in marketing strategies as well. Hence, to safely make full use of the products that flood the market today, their proper usage should be understood and executed correctly. This article will attempt to outline the types and usage of skincare cosmetic products that flourish the market through tracing the history of cosmetic technologies and marketing strategies.
The aim of this lecture series is to expand dermatologists interested in Japanese Cosmetic Science Society by providing basic scientific knowledge of cosmetics. Articles of this series planed for two years will include various aspects of cosmetic products and their functions, regulations, relations with troubled skin. I hope that this lecture series will be helpful, not only for dermatologists, but also for paramedicals and cosmetic scientists.
Why people wear make-up is a fundamental and wide-ranging question. Make-up and skin care have evolved over the course of time through the influence of society and culture. Having undergone many changes, the term “make-up” has become a word that encompasses numerous meanings and concepts. In an attempt to answer the question why people wear make-up, this paper first analyzes what constitutes make-up from the viewpoint of make-up activities and the meaning of make-up, then it traces the changes in what comprises make-up in Japanese cosmetic culture. Lastly it examines modern make-up from three perspectives: the allure of women’s appearance, the effects of make-up, and the interpretation of beauty culture.