In recent years, the harmful effects of blue light (400 - 500 nm) as a component of visible light (400 - 700 nm) have increasingly gained attention of science, industry, and consumers. To date, only a few in vivo test...In recent years, the harmful effects of blue light (400 - 500 nm) as a component of visible light (400 - 700 nm) have increasingly gained attention of science, industry, and consumers. To date, only a few in vivo test methods for measuring the effects of blue light on the skin have been described. A direct measurement method that can detect the immediate effects of blue light on the epidermal permeability barrier (EPB) is still lacking. In this study, we present a new methodological approach that can be used to investigate both the protective and regenerative effects of cosmetic products on the EPB after blue light irradiation. In a study with 14 female volunteers, it was investigated whether the regular application of an O/W emulsion (day cream) can strengthen and protect the epidermal barrier against damaging blue light radiation of 60 J/cm2 (protective study design) and also whether a disruption of the epidermal barrier caused by blue light radiation is restored faster and better by the regular application of another O/W emulsion (night cream) than in product-untreated skin (regenerative study design). The two O/W emulsions are different in plant oil, active ingredient composition and texture. The seven-day treatment with the day cream initially led to a significant increase in the normalized lipid lamellae length in the intercellular space, whereas the irradiation with blue light after 24 hours led to a significant decrease in the lipid lamellae length in the untreated test area, but not in the area previously treated with the product. Regarding the regenerative study design, a two-day treatment with the night cream was able to restore a blue-light-induced decrease in lipid lamellae length in the intercellular space. In summary, with the study designs presented here, the protective and regenerative effect of two cosmetic products could be demonstrated for the first time on the integrity of the EPB after blue light irradiation and the data showed that the Lipbarvis® method is suitable for investigating the damaging effects of blue light on the EPB in vivo.展开更多
Subjective evaluations are nowadays applied more commonly in cosmetic product assessment. They are used in quality control, product development steps and efficacy studies for claim support. Several studies have been p...Subjective evaluations are nowadays applied more commonly in cosmetic product assessment. They are used in quality control, product development steps and efficacy studies for claim support. Several studies have been published to determine the adequate number of panelists, but recommendations and guidelines dealing with this topic are rare in the cosmetic sector. The aim of the present pilot study was to recommend a suitable study plan and define the adequate consumer panel size for cosmetic consumer assessment. A questionnaire-based product evaluation study, with three different cosmetic products, was organized as a consumer test using a seven-point scale. As a last step, a specific statistical calculation was performed to define the minimum sample size. It showed that the minimum sample size, besides the obvious statistical parameters of standard deviation and confidence interval, also depends on age and gender of the panelists and product assessment item. Utilizing a CI of 95% a minimum of 60 panelists seems to be sufficient for home-use-test (HUT) with a given seven-point scale. A minimum of 101 panelists are shown to be sufficient utilizing a CI of 99%.展开更多
<strong>OBJECTIVE:</strong> <span style="font-family:;" "=""><span style="font-family:Verdana;">The physiological skin surface pH is crucial for several epide...<strong>OBJECTIVE:</strong> <span style="font-family:;" "=""><span style="font-family:Verdana;">The physiological skin surface pH is crucial for several epidermal barrier functions, like stratum corneum integrity, cohesion and restoration. Alterations of the “normal” acidic nature of the skin surface have been shown to correlate with specific skin conditions like aged or inflamed skin and are leading to impaired skin barrier function and formation. It is previously demonstrated that topical acidification in atopic dermatitis improves stratum corneum function, skin barrier structure and clinical signs in dermatitis. Against this background, we examined the impact of a slightly acidic skin care product containing urea on stratum corneum hydration, skin surface pH and epidermal barrier function in subjects with dry skin and atopic diathesis. </span><b><span style="font-family:Verdana;">METHODS:</span></b><span style="font-family:Verdana;"> Stratum corneum hydration, skin surface pH and transepidermal water loss were biophysically measured before and after a 4-week treatment period with the test product (pH 4.5, 10% urea) compared to the reference product in 25 volunteers. In addition, dynamic epidermal barrier parameters like stratum corneum integrity, cohesion and recovery were investigated by using a previously described tape stripping approach. </span><b><span style="font-family:Verdana;">RESULTS:</span></b><span style="font-family:Verdana;"> It was shown that the test product (pH 4.5, 10% urea) significantly elevated stratum corneum hydration and improved the acidic nature of the skin surface by lowering the skin surface pH to a greater extent compared to the reference product. After the 4-week treatment period a significant faster barrier restoration was detected on the test site treated with the test product compared to the reference product. Moreover, the test product strengthens the skin barrier integrity and cohesion. </span><b><span style="font-family:Verdana;">CONCLUSION: </span></b><span style="font-family:Verdana;">The present marketed skin care lotion was shown to increase epidermal barrier function after 4 weeks of application. Balancing and controlling the skin surface pH in subjects with dry and atopic-prone skin by application of the herein tested o/w emulsion with a given pH of 4.5, in combination with a 10% urea content seems to be effective and beneficial. The results are important for the formulation of topical products for dry and atopic-prone skin.</span></span>展开更多
In the wake of ever-increasing environmental pollution, human skin in the modern urban world is exposed to increased levels of harmful environmental pollutants. Many studies have shown that these pollutants can weaken...In the wake of ever-increasing environmental pollution, human skin in the modern urban world is exposed to increased levels of harmful environmental pollutants. Many studies have shown that these pollutants can weaken the epidermal skin barrier and thus facilitate the penetration of these substances into the skin. An important goal of modern skin care against harmful environmental influences should therefore be to protect and strengthen the epidermal barrier and to repair occurring damage quickly and efficiently. With this in mind, in the present study we investigated what damage cigarette smoke causes to the epidermal barrier and 1) whether the regular application of a O/W emulsion (Day Cream) can protectively strengthen the epidermal barrier against environmental damage and 2) whether a cigarette smoke-induced disruption of the epidermal barrier is restored faster and better by the regular application of a another O/W emulsion (Night Cream) than in product-untreated skin. The two products are slightly different in plant-oil, active ingredient composition and texture. Firstly, the study has shown that the Lipbarvis<sup>?</sup> method is suitable for measuring the effect of cigarette smoke, in contrast to conventional biophysical measurement methods (transepidermal water loss, skin hydration). Secondly, both products were able to improve skin barrier function in the corresponding test scenario. This was demonstrated for both test products by a significantly reduced TEWL, significantly increased skin hydration and significantly improved length of the lipid lamellae in the intercellular space, as well as the protective effect of the day cream on the epidermal skin barrier and the regenerative properties of the tested night cream. .展开更多
文摘In recent years, the harmful effects of blue light (400 - 500 nm) as a component of visible light (400 - 700 nm) have increasingly gained attention of science, industry, and consumers. To date, only a few in vivo test methods for measuring the effects of blue light on the skin have been described. A direct measurement method that can detect the immediate effects of blue light on the epidermal permeability barrier (EPB) is still lacking. In this study, we present a new methodological approach that can be used to investigate both the protective and regenerative effects of cosmetic products on the EPB after blue light irradiation. In a study with 14 female volunteers, it was investigated whether the regular application of an O/W emulsion (day cream) can strengthen and protect the epidermal barrier against damaging blue light radiation of 60 J/cm2 (protective study design) and also whether a disruption of the epidermal barrier caused by blue light radiation is restored faster and better by the regular application of another O/W emulsion (night cream) than in product-untreated skin (regenerative study design). The two O/W emulsions are different in plant oil, active ingredient composition and texture. The seven-day treatment with the day cream initially led to a significant increase in the normalized lipid lamellae length in the intercellular space, whereas the irradiation with blue light after 24 hours led to a significant decrease in the lipid lamellae length in the untreated test area, but not in the area previously treated with the product. Regarding the regenerative study design, a two-day treatment with the night cream was able to restore a blue-light-induced decrease in lipid lamellae length in the intercellular space. In summary, with the study designs presented here, the protective and regenerative effect of two cosmetic products could be demonstrated for the first time on the integrity of the EPB after blue light irradiation and the data showed that the Lipbarvis® method is suitable for investigating the damaging effects of blue light on the EPB in vivo.
文摘Subjective evaluations are nowadays applied more commonly in cosmetic product assessment. They are used in quality control, product development steps and efficacy studies for claim support. Several studies have been published to determine the adequate number of panelists, but recommendations and guidelines dealing with this topic are rare in the cosmetic sector. The aim of the present pilot study was to recommend a suitable study plan and define the adequate consumer panel size for cosmetic consumer assessment. A questionnaire-based product evaluation study, with three different cosmetic products, was organized as a consumer test using a seven-point scale. As a last step, a specific statistical calculation was performed to define the minimum sample size. It showed that the minimum sample size, besides the obvious statistical parameters of standard deviation and confidence interval, also depends on age and gender of the panelists and product assessment item. Utilizing a CI of 95% a minimum of 60 panelists seems to be sufficient for home-use-test (HUT) with a given seven-point scale. A minimum of 101 panelists are shown to be sufficient utilizing a CI of 99%.
文摘<strong>OBJECTIVE:</strong> <span style="font-family:;" "=""><span style="font-family:Verdana;">The physiological skin surface pH is crucial for several epidermal barrier functions, like stratum corneum integrity, cohesion and restoration. Alterations of the “normal” acidic nature of the skin surface have been shown to correlate with specific skin conditions like aged or inflamed skin and are leading to impaired skin barrier function and formation. It is previously demonstrated that topical acidification in atopic dermatitis improves stratum corneum function, skin barrier structure and clinical signs in dermatitis. Against this background, we examined the impact of a slightly acidic skin care product containing urea on stratum corneum hydration, skin surface pH and epidermal barrier function in subjects with dry skin and atopic diathesis. </span><b><span style="font-family:Verdana;">METHODS:</span></b><span style="font-family:Verdana;"> Stratum corneum hydration, skin surface pH and transepidermal water loss were biophysically measured before and after a 4-week treatment period with the test product (pH 4.5, 10% urea) compared to the reference product in 25 volunteers. In addition, dynamic epidermal barrier parameters like stratum corneum integrity, cohesion and recovery were investigated by using a previously described tape stripping approach. </span><b><span style="font-family:Verdana;">RESULTS:</span></b><span style="font-family:Verdana;"> It was shown that the test product (pH 4.5, 10% urea) significantly elevated stratum corneum hydration and improved the acidic nature of the skin surface by lowering the skin surface pH to a greater extent compared to the reference product. After the 4-week treatment period a significant faster barrier restoration was detected on the test site treated with the test product compared to the reference product. Moreover, the test product strengthens the skin barrier integrity and cohesion. </span><b><span style="font-family:Verdana;">CONCLUSION: </span></b><span style="font-family:Verdana;">The present marketed skin care lotion was shown to increase epidermal barrier function after 4 weeks of application. Balancing and controlling the skin surface pH in subjects with dry and atopic-prone skin by application of the herein tested o/w emulsion with a given pH of 4.5, in combination with a 10% urea content seems to be effective and beneficial. The results are important for the formulation of topical products for dry and atopic-prone skin.</span></span>
文摘In the wake of ever-increasing environmental pollution, human skin in the modern urban world is exposed to increased levels of harmful environmental pollutants. Many studies have shown that these pollutants can weaken the epidermal skin barrier and thus facilitate the penetration of these substances into the skin. An important goal of modern skin care against harmful environmental influences should therefore be to protect and strengthen the epidermal barrier and to repair occurring damage quickly and efficiently. With this in mind, in the present study we investigated what damage cigarette smoke causes to the epidermal barrier and 1) whether the regular application of a O/W emulsion (Day Cream) can protectively strengthen the epidermal barrier against environmental damage and 2) whether a cigarette smoke-induced disruption of the epidermal barrier is restored faster and better by the regular application of a another O/W emulsion (Night Cream) than in product-untreated skin. The two products are slightly different in plant-oil, active ingredient composition and texture. Firstly, the study has shown that the Lipbarvis<sup>?</sup> method is suitable for measuring the effect of cigarette smoke, in contrast to conventional biophysical measurement methods (transepidermal water loss, skin hydration). Secondly, both products were able to improve skin barrier function in the corresponding test scenario. This was demonstrated for both test products by a significantly reduced TEWL, significantly increased skin hydration and significantly improved length of the lipid lamellae in the intercellular space, as well as the protective effect of the day cream on the epidermal skin barrier and the regenerative properties of the tested night cream. .
