Shiseido discovers that ``pure retinol'' has a softening effect on the stratum corneum

 Shiseido utilizes its proprietary "inner and outer skin 3D elastic imaging technology". When the stratum corneum hardens, the mechanical stress applied to the dermis increases when the skin moves due to facial expressions, etc. It was confirmed that the skin gap between the layer and the dermis) progresses. In addition, it was discovered that the active ingredient "pure retinol", which has been shown to be effective in improving wrinkles, has a softening effect on the stratum corneum, revealing that it has a new function to prevent the progression of wrinkles from the surface of the skin to the depths of the skin. made it

While pure retinol has a high skin-improving effect, it is easily decomposed by oxygen, heat, light, etc., so in order to fully demonstrate its effect, it is necessary to keep it stable and deliver it to the skin reliably. In the course of over 30 years of research on retinol, the company has developed a proprietary technology called "Shiseido Retinol TripleLock Technology" that can stably blend pure retinol into products, and has demonstrated the effects of "pure retinol". It has been achieved to deliver to the skin reliably.

Based on more than 30 years of research on retinol, the company was the first company in Japan to receive approval from the Ministry of Health, Labor and Welfare to claim that the active ingredient "pure retinol" is effective in improving wrinkles. The effect is certain, and we have clarified the function leading to wrinkle improvement in each layer from the epidermis, which is the shallow layer of the skin, to the deep dermis, and confirmed the effect on wrinkles on the neck.

While it has a definite improvement effect, it takes several weeks for physiological changes in the skin, so in search of more efficient wrinkle improvement, we have also conducted research on the mechanical structure of the skin to get to the root of wrinkles. Triggered by the world's first development of "3D elastic imaging technology inside and outside the skin" that can measure the elasticity of each microscopic area of ​​the skin in three dimensions, which was considered impossible by conventional mechanical measurement, the stratum corneum is aging. The dermis layer softens while the dermal layer becomes stiffer as the skin becomes stiffer, and this gap in hardness causes wrinkles to form.

In this research, we aimed to develop a method to prevent and improve wrinkles more quickly and reliably, and focused on the hardening of the stratum corneum, which is related to the "root cause of wrinkles."

In order to verify the effect of the hardening of the stratum corneum on wrinkles, a model reflecting the actual skin structure was constructed on a computer, and deformation due to compression when the stratum corneum was soft and hard was investigated. I did a simulation.

As a result, it became clear that in the model with a hard stratum corneum, the deformation of the dermis increased and the mechanical stress applied to the dermis increased. Past research has found that mechanical stress applied to the dermis promotes the production of collagen-degrading enzymes, so if the stratum corneum is stiff, mechanical stress increases when the skin moves due to facial expressions, etc. , It is thought that the softening of the dermis is induced, leading to the progression of the “two-layer skin gap” that is the root cause of wrinkles.

In other words, it has been suggested that the hardening of the stratum corneum leads to the progression of wrinkles from the skin surface to the depth, and it has become clear that keeping the stratum corneum soft is an important care for wrinkle improvement.

A cream containing pure retinol for 35 healthy Japanese women with shallow to moderately deep wrinkles on the outer corner of the eyes, in accordance with the "Guidelines for evaluating anti-wrinkle products for acquiring new efficacy" formulated by the Japanese Cosmetic Science Society. was conducted for 12 weeks, and changes in the hardness of the stratum corneum were evaluated. As a result, when the cream containing pure retinol was used continuously for 4 weeks, the stratum corneum became significantly softer than before use. It has been shown.

We have shown that pure retinol has the effect of softening the stratum corneum physiologically and fundamentally, but because it takes several weeks to induce physiological changes, we believe that the stratum corneum can be softened in a short period of time. We also verified the ingredients that soften the skin and prevent wrinkles.

As a result, as a result of confirming the elastic modulus of the stratum corneum immediately after applying components blended with complex oils including castor oil and bis-diglyceryl polyacyladipate-2 to the stratum corneum sheet, it was found that the application of these components resulted in short-term elasticity. was shown to soften the stratum corneum. In addition, when the hardness of the stratum corneum on the surface of the skin was measured 10 minutes after applying these ingredients to the actual skin, it changed to soft. The effect disappears when the oil is washed away from the skin, but when used in combination with pure retinol, it is expected to instantly soften and loosen the skin while supporting the fundamental softening effect of the skin. It is said that it is possible to maximize the conversion effect.