Isabel Simon’s scientific contributions

Objective: Cleansing is an important human ritual practiced for hygiene, well-being, and relaxation over centuries. As part of body care it is often taken for granted, yet its relevance cannot be underestimated. Although cleansing the skin may seem trivial to some, it is accepted, that this fundamental function of skin cleansing products is highly complex, diverse, and crucial for a variety of reasons in the personal, public, healthcare, and dermatological settings. Employing a comprehensive and strategic approach in viewing cleansing and its rituals, supports innovation, understanding, and development. Apart from being a fundamental function, as far as we know, there is no comprehensive presentation of skin cleansing with all its effects besides "removing dirt". To our knowledge, comprehensive analyses on the multi-dimensional facets of skin cleansing are either rare or not published. Against this background, we examine the importance of cleansing in terms of function, relevance, and concepts. Methods: First, the key functions and efficacies of skin cleansing were investigated by literature research. Based on this survey, the functions were analysed, sorted, and merged and a novel approach of skin cleansing "dimensions" was developed. Herewith, we took into consideration the evolution of skin cleansing in terms of concept evolution, complexity, and testing methods for cleansing products and their claims. Conclusion: Several multi-dimensional functions of skin cleansing were identified and then established to five skin cleansing dimensions, namely: Hygienic and medical importance; Socio-cultural and interpersonal relevance; Mood, emotion, and well-being; Cosmetic and aesthetic function; and Corneobiological interactions. It became obvious, that these five dimensions with their corresponding eleven sub-dimensions, are influenced by each other throughout history by culture and society, technical progress, scientific knowledge and consumer trends. This article presents the enormous complexity of skin cleansing. Skin cleansing has evolved from basic care up to a highly complex and diverse cosmetic product category in terms technology, efficacy, and usage routine(s). In view of future challenges, such as the effects of climate and associated lifestyle changes, the development of skin cleansing will remain an exciting and important topic and thus will finally, again, further increase the complexity of skin cleansing itself.

Epidermal barrier dysfunction can lead to xerotic skin and promote skin disorders like atopic dermatitis. Atopic skin is characterized by reduced water-retaining compounds, altered lipid composition and elevated skin pH. Against this background, a study was conducted to investigate the impact of a specific skin care product on epidermal barrier function in dry and atopic-prone skin. A marketed pH 4.5 cosmetic formulation containing 10% urea and specific plant oils was evaluated on 25 subjects with dry and atopic-prone skin. Measurements of skin hydration, pH, and barrier function were performed before and after 3 weeks of product usage. Additionally, visual scoring and stratum corneum lipid analysis using electron microscopy were conducted to investigate lipid composition. An improved skin hydration compared to the untreated area and a tendency to decrease the baseline elevated skin surface pH were observed. The visual scoring showed reduced dryness, roughness, and tension through the application. Furthermore, the stratum corneum lipid matrix was improved in terms of lipid content and organization. The combination of an acidic product's pH, a relevant urea content and effective plant oils is shown to be beneficial in terms of improving the skin barrier function, structure and appearance and is recommended for dry and atopic-prone skin.

Aromacological cosmetic product efficacy: activating and stimulating shower product

BACKGROUND: Today’s global trends in sustainability and mindfulness have gained tremendous impact on lifestyle and consumer behaviour. In view of cosmetics, an increased awareness on convenient, intensive skin care is key, implicating superior product efficacy but also novel test designs for claim support. Many study designs to evaluate cosmetics are published with objective or subjective parameters [1-3]. The present work expands the opportunities for evaluation by focusing on long-lasting effectiveness. A test design with 3-week treatment succeeded by 1-week regression phase was developed. METHODS: The investigation was divided into study A and B. Study A was conducted to evaluate the effectiveness and regression, i.e. maintenance of effectiveness during follow-up (n=18, female, age: 53.511.2). After measurement of skin hydration [4] and assessment of skin dryness and feeling (10-point scale) at baseline (t0) the product was applied for three weeks. Further examinations were performed after 3-week product use (t1) and additionally 24h (t2), 48h (t3), 72h (t4), 96h (t5) and 7 days (t6) thereafter. Study A was complemented by study B: questionnaire-based evaluation after 3-week by 33 female subjects (age: 49.412.5). RESULTS: Study A showed significantly higher skin hydration compared to the untreated test site after 3-week of product use. The hydration lasted up to 96h after last application. Moreover, after 3-week of product use significant difference in skin dryness and feeling were observed and remaining throughout the regression phase. In study B the subjects agreed to all statements, including long-term effectiveness. CONCLUSION: The present work shows long-lasting, sustainable effects on skin hydration and caring properties after 3-week application. Especially the follow-up examination provides a suitable approach to uncover and evaluate such superior, convenience-related skin care effects. Finally, such novel study designs allow to highlight innovative, cosmetic efficacies and product claims, thereby addressing contemporary consumer needs in cosmetics and beyond.

BACKGROUND: Current global trends and increasing consumer needs demand superior cosmetic product efficacies, requiring a constant evolution of test designs for product evaluation. Dexpanthenol (DEX) is broadly used for decades as ingredient in various cosmetic applications and thereby known for several proven functions [1], like increasing skin hydration, supporting moisture retaining [2], and enhancing epidermal barrier recovery [3]. In contrast, data concerning DEX kinetic and penetration are rare. Therefore, the present work focuses on the penetration of DEX. METHODS: Three pilot tests with Raman measurements were conducted to evaluate DEX penetration after application of a given o/w emulsion (Part I, II, III). For each test part, the study panel, test site, application mode, and measurement set-up were differently defined. RESULTS: DEX as active ingredient of the investigated skin care lotion is well detectable on the skin surface and down to a skin depth of 10μm up to 20μm. Occlusive conditions led to DEX penetration into the stratum disjunctum and as well into the stratum compactum. On hydrated skin DEX penetrates into the stratum disjunctum at measurable amounts. After 5 days open product application DEX is measurable even 12-16 hours after the last application and was significantly enriched in the upper layers of the stratum corneum. CONCLUSION: Comparing the test results, DEX could be detected in the stratum corneum down to a skin depth of 5, 10, and 20µm, depending on the test set-up. Such investigations provide knowledge on the interaction between mode of application, measurement set-up, and active ingredient penetration. Finally, the present work helps to improve product development regarding active targeting activities and additionally provides insights to choose an appropriate test set-up for such product investigations.

The herewith evaluated skin care emulsion was shown to improve skin barrier integrity, cohesion and recovery in xerotic and atopic-prone skin. The key characteristics of the test products were a given acidic pH of 4.5 and a urea concentration of 10%.

Psyhophysiological measurements to investigate aromacological effects under usage of massage oils.