Clinical Testing of Dermo-Protective Products against Environmental, Chemical and Climatic Insults
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Presented by: Nalini Kaul
Our skin reflects the state of our health. Exposure of the skin to external insults like chemicals (detergents, soaps), climate (dry, cold conditions) and environmental (pollution) besides harming the protective ability of the skin, impacts skin properties and causes acute or chronic damage to the skin barrier. There is need to protect the skin from onslaught of various insults and to conserve and restore hydration, barrier function and protect it from pollutants. Many products with dermo-protective properties are available and new ones are being introduced with actives to clean, soothe, restore, reinforce, protect, treat and maintain our skin in good condition.
Three in vivo models were used to assess the efficacy of dermo-protectants against environmental, chemical and climatic insults:
Dermo-protection against Environmental Pollution: Although, our skin acts as a biological shield against pro-oxidative chemicals and physical air pollutants, prolonged or repetitive exposure to high levels of these pollutants may have vastly negative effects on the skin. In this study design antipollution efficacy assessment of cosmetic product against particulate matter (2.5PM) was studied. Three sites were marked on the inner forearm of eligible subjects. Each site was divided in half with one side designated for treatment and the other side designated as untreated. Prior to application of the test article, photographs were taken of each site and served as baseline. Test articles 1 and 2 were applied to two sites. Half of the site was treated and the other half was untreated. A 15-minute time-period was allowed for the TA to be absorbed into the skin after which the test sites were exposed to coal dust 2.5PM and an additional 15 mins were allowed for the dust to settle on the skin. A clinical photographer took photos and a trained grader evaluated the skin. The untreated site was washed with the standard surfactant and graded at the same timepoints.
Dermo-protection against Chemical Insult: Sodium Lauryl sulfate (SLS), a common ingredient in skin care products, can cause skin dryness, erythema and inflammation depending on its concentration and exposure. A randomized double blind, design in 30 healthy subjects consisting of a 3-day run in phase and 2-week treatment phase. The objective was to compare Trans Epidermal Water Loss (TEWL) and skin capacitance pre and post use of a specific moisturizer used twice daily for 15 days. Two rectangular sites (treated and untreated) were assigned to each outer leg of subjects. No skin products were allowed except washing with water. TEWL was measured pre and post application of SLS to compare moisturizer treated and untreated sites. Following the final application, half of test site was exposed to SLS for approximately 12 hours. Final assessments were performed on Day 15, approximately 24 hours after SLS application.
Dermo-protection against Climatic Insult: Skin dryness causes corneocyte shedding leading to roughness, discomfort and itchiness and, if unattended, with time can lead to irritation and even inflammation. Moisturizers help repair the skin barrier by retaining and helping increase the water content of the skin and by reducing the trans epidermal water loss. We tested the efficacy of a moisturizer product on dry skin over an 8-hour wear period following a single application. At the baseline visit 30 healthy subjects who met eligibility criteria with visual dryness and tactile roughness scores of 2 or greater continued to the treatment phase. Two test sites were marked on the right and left lateral legs. Clinical assessments of visual dryness and roughness, tactile roughness and instrumental measurement of hydration and trans epidermal water loss were taken at baseline prior to first application and then post application at various time points.
Our results from the three skin models using test methods presented under standardized conditions show dermo-protection and its extent, evident with the test articles used in relation to hydration, barrier protection and removal of pollution.
In conclusion: Being in direct contact with the skin, dermo-protectants help protect and modulate skin characteristics and functioning, thus making them unique and versatile, outstepping the original boundaries of a product providing beauty alone.
Three in vivo models were used to assess the efficacy of dermo-protectants against environmental, chemical and climatic insults:
Dermo-protection against Environmental Pollution: Although, our skin acts as a biological shield against pro-oxidative chemicals and physical air pollutants, prolonged or repetitive exposure to high levels of these pollutants may have vastly negative effects on the skin. In this study design antipollution efficacy assessment of cosmetic product against particulate matter (2.5PM) was studied. Three sites were marked on the inner forearm of eligible subjects. Each site was divided in half with one side designated for treatment and the other side designated as untreated. Prior to application of the test article, photographs were taken of each site and served as baseline. Test articles 1 and 2 were applied to two sites. Half of the site was treated and the other half was untreated. A 15-minute time-period was allowed for the TA to be absorbed into the skin after which the test sites were exposed to coal dust 2.5PM and an additional 15 mins were allowed for the dust to settle on the skin. A clinical photographer took photos and a trained grader evaluated the skin. The untreated site was washed with the standard surfactant and graded at the same timepoints.
Dermo-protection against Chemical Insult: Sodium Lauryl sulfate (SLS), a common ingredient in skin care products, can cause skin dryness, erythema and inflammation depending on its concentration and exposure. A randomized double blind, design in 30 healthy subjects consisting of a 3-day run in phase and 2-week treatment phase. The objective was to compare Trans Epidermal Water Loss (TEWL) and skin capacitance pre and post use of a specific moisturizer used twice daily for 15 days. Two rectangular sites (treated and untreated) were assigned to each outer leg of subjects. No skin products were allowed except washing with water. TEWL was measured pre and post application of SLS to compare moisturizer treated and untreated sites. Following the final application, half of test site was exposed to SLS for approximately 12 hours. Final assessments were performed on Day 15, approximately 24 hours after SLS application.
Dermo-protection against Climatic Insult: Skin dryness causes corneocyte shedding leading to roughness, discomfort and itchiness and, if unattended, with time can lead to irritation and even inflammation. Moisturizers help repair the skin barrier by retaining and helping increase the water content of the skin and by reducing the trans epidermal water loss. We tested the efficacy of a moisturizer product on dry skin over an 8-hour wear period following a single application. At the baseline visit 30 healthy subjects who met eligibility criteria with visual dryness and tactile roughness scores of 2 or greater continued to the treatment phase. Two test sites were marked on the right and left lateral legs. Clinical assessments of visual dryness and roughness, tactile roughness and instrumental measurement of hydration and trans epidermal water loss were taken at baseline prior to first application and then post application at various time points.
Our results from the three skin models using test methods presented under standardized conditions show dermo-protection and its extent, evident with the test articles used in relation to hydration, barrier protection and removal of pollution.
In conclusion: Being in direct contact with the skin, dermo-protectants help protect and modulate skin characteristics and functioning, thus making them unique and versatile, outstepping the original boundaries of a product providing beauty alone.