Instant Wrinkle Reduction Products that Look and Feel Great for Healthy Skin
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Presented by: Sebastian Hendrickx-Rodriguez
Introduction: Anti-aging cosmetics aim to reduce the appearance of fine-lines and wrinkles in the skin, benefits that typically accumulate over weeks and months. However, recent advances in skincare formulations have generated interest in products with instant anti-aging benefits (i.e., within a matter of minutes). Such products, while demonstrating short-term benefits, can often have unwanted and potentially damaging consequences for healthy skin, such as uncomfortable tightening and drying of the skin. Furthermore, long term-benefits are typically discarded during the development of these instant anti-aging products.
Our aim was to develop a formulation that 1) instantly reduced the appearance of wrinkles, 2) did not create undesired feelings of tightness, and 3) provided long-term skin health benefits to the consumer. Two types of ingredients were used to achieve this goal: film-forming polymers and hygroscopic molecules. The former leaves an invisible film on the skin surface with significant in-plane contractions. The resulting tensile stresses increase roughness at the microscale through local buckling; but these stresses also propagate strain waves into deeper layers where mechanoreceptors send signals of tightness to the brain. In contrast, hygroscopic components diffuse into the topmost layers of skin, helping it reduce in-plane stresses. By combining a film-forming polymer that ‘micro-textures’ the skin and hygroscopic components that diffuse into the skin, we optimize both appearance and sensation.
Methods: The stratum corneum (SC) is the outermost layer of human skin. This layer was isolated and tested in vitro using a substrate curvature technique to measure SC stresses. These mechanical stresses develop during drying and film formation. Measurements were done before and after cream application, and immediately after cream removal. Three formulations were investigated: the full composition, the cream without film-forming ingredients, and the cream without hygroscopic components.
In conjunction to these in vitro measurements, a US clinical study was conducted with male and female participants (n=41, <10% males) aged 40-70. Participants had moderate to severe periocular fine lines and wrinkles at the start of the study. Volunteers were instructed to apply the full formulation daily on crow’s feet and under eye areas for eight weeks, with clinical grading occurring periodically throughout the study.
Results: The cream without film-forming ingredients decreased SC stresses by 5%, while the cream without hygroscopic components increased SC stresses by 6%. Together the two effects offset as seen in the full formulation which increased SC stresses by 1%. Upon removal, the cream without film-forming ingredients reduced SC stresses by an additional 7% (a total reduction of 12% to control), indicating that hygroscopic components diffused further into the skin. In contrast, upon removal of the cream without hygroscopic components, stresses returned to control levels indicating that the film-forming ingredients remain solely on the surface of the skin. Upon removal of the full formulation, stresses decreased by 10% compared to control.
Results from the clinical study showed that over 70% of participants experienced tightening within five minutes of application, 81% had fewer under eye fine lines and 78% had fewer crow’s feet fine lines by the end of the study, illustrating clear long-term benefits. In addition, over 70% said product feels comfortable on skin directly after application, and 85% said product is gentle enough for daily use after 4 weeks. No other tolerability parameters, visual acuity, or slit-lamp ophthalmological examination parameters (including subjective sensation) changed significantly between pre- and post-application, indicating comfort and safety of the formulation.
Discussion: This study begins to explain how film-forming polymers combat skin wrinkles both instantaneously and long-term, while also providing remedies to the discomfort often accompanying these formulations. We demonstrate that these films by themselves increase the biomechanical stress experienced by the SC. These stresses (of a few MPa) micro-texture the skin to reduce the appearance of harsh wrinkles, but also activate mechanoreceptors located at the dermis-epidermis boundary. By including hygroscopic components that relax skin stresses, it is possible to counterbalance the effect of film-forming polymers. We show that combining these two approaches in an optimal manner generates a product with the desired instant benefits, a pleasant sensorial feeling, and the ability to deliver long-term improvements to the appearance of fine lines around the eyes.
Our aim was to develop a formulation that 1) instantly reduced the appearance of wrinkles, 2) did not create undesired feelings of tightness, and 3) provided long-term skin health benefits to the consumer. Two types of ingredients were used to achieve this goal: film-forming polymers and hygroscopic molecules. The former leaves an invisible film on the skin surface with significant in-plane contractions. The resulting tensile stresses increase roughness at the microscale through local buckling; but these stresses also propagate strain waves into deeper layers where mechanoreceptors send signals of tightness to the brain. In contrast, hygroscopic components diffuse into the topmost layers of skin, helping it reduce in-plane stresses. By combining a film-forming polymer that ‘micro-textures’ the skin and hygroscopic components that diffuse into the skin, we optimize both appearance and sensation.
Methods: The stratum corneum (SC) is the outermost layer of human skin. This layer was isolated and tested in vitro using a substrate curvature technique to measure SC stresses. These mechanical stresses develop during drying and film formation. Measurements were done before and after cream application, and immediately after cream removal. Three formulations were investigated: the full composition, the cream without film-forming ingredients, and the cream without hygroscopic components.
In conjunction to these in vitro measurements, a US clinical study was conducted with male and female participants (n=41, <10% males) aged 40-70. Participants had moderate to severe periocular fine lines and wrinkles at the start of the study. Volunteers were instructed to apply the full formulation daily on crow’s feet and under eye areas for eight weeks, with clinical grading occurring periodically throughout the study.
Results: The cream without film-forming ingredients decreased SC stresses by 5%, while the cream without hygroscopic components increased SC stresses by 6%. Together the two effects offset as seen in the full formulation which increased SC stresses by 1%. Upon removal, the cream without film-forming ingredients reduced SC stresses by an additional 7% (a total reduction of 12% to control), indicating that hygroscopic components diffused further into the skin. In contrast, upon removal of the cream without hygroscopic components, stresses returned to control levels indicating that the film-forming ingredients remain solely on the surface of the skin. Upon removal of the full formulation, stresses decreased by 10% compared to control.
Results from the clinical study showed that over 70% of participants experienced tightening within five minutes of application, 81% had fewer under eye fine lines and 78% had fewer crow’s feet fine lines by the end of the study, illustrating clear long-term benefits. In addition, over 70% said product feels comfortable on skin directly after application, and 85% said product is gentle enough for daily use after 4 weeks. No other tolerability parameters, visual acuity, or slit-lamp ophthalmological examination parameters (including subjective sensation) changed significantly between pre- and post-application, indicating comfort and safety of the formulation.
Discussion: This study begins to explain how film-forming polymers combat skin wrinkles both instantaneously and long-term, while also providing remedies to the discomfort often accompanying these formulations. We demonstrate that these films by themselves increase the biomechanical stress experienced by the SC. These stresses (of a few MPa) micro-texture the skin to reduce the appearance of harsh wrinkles, but also activate mechanoreceptors located at the dermis-epidermis boundary. By including hygroscopic components that relax skin stresses, it is possible to counterbalance the effect of film-forming polymers. We show that combining these two approaches in an optimal manner generates a product with the desired instant benefits, a pleasant sensorial feeling, and the ability to deliver long-term improvements to the appearance of fine lines around the eyes.