Composition for increasing bound water in the stratum corneum

Abstract

To provide a technique capable of enhancing bound water in a horny layer.SOLUTION: The present invention provides a composition for enhancing bound water in a horny layer or a composition for suppressing moisture transpiration in a horny layer, each containing component (A) glycerol and (B) polyglycerol. Suitably, the component (B) is polyglycerol-3. Suitably, the mass ratio of the component (A) content and the component (B) content in the composition is 1: 0.01-0.5.SELECTED DRAWING: None

Description

Technical Field

[0001] The present technology relates to a composition for enhancing bound water in the stratum corneum, a composition for suppressing water transpiration in the stratum corneum, and the like.

Background Art

[0002] The skin is mainly divided into the epidermis, dermis, and subcutaneous tissue, and the epidermis is further divided into the sebum membrane, stratum corneum, granular layer, spinous layer, and basal layer in order from the surface.

[0003] The stratum corneum, which is located in the outermost layer of the skin, consists of dead cells approximately 80% composed of keratin protein and plays a role in the barrier function of protecting the skin from external stimuli such as dryness, ultraviolet rays, and air pollutants. The stratum corneum is formed by the layered overlapping of stratum corneum cells made of hard keratin protein and is dense so as not to leak out the body's moisture and body fluids. The water content of the stratum corneum is said to largely depend on the environmental humidity of the outside world or the stratum corneum moisturizing function. When the water content of the stratum corneum changes, water molecules are stored mainly in the keratin fibers and NMF in the stratum corneum cells, which is said to affect the flexibility of the stratum corneum.

[0004] Furthermore, internal factors such as aging, diseases, stress, hormonal abnormalities, and external factors such as dryness, ultraviolet rays, etc. reduce moisture and extracellular matrix (collagen, hyaluronic acid, etc.) from the skin tissue, or reduce the functions of the epidermis and dermis of the skin. The decline in skin function may appear in a state such as skin wrinkles, loss of elasticity (sagging), rough skin, etc.

[0005] And, as skin care for keeping the skin beautiful, it is generally practiced to supplement the stratum corneum with moisture and oil. For example, an agent for improving the water retention ability of the epidermis and / or stratum corneum containing apple young fruit extract as an active ingredient has been proposed.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-90465 [Non-patent literature]

[0007] [Non-Patent Document 1] Genmayu Imokawa, Oil Chemistry, 44, 10, 51-66 (1995) [Overview of the project] [Problems that the invention aims to solve]

[0008] Traditionally, skincare has focused on the evaporation of free water within the stratum corneum, but the inventors decided to focus on bound water within the stratum corneum. However, there is still insufficient knowledge regarding ingredients that can enhance bound water within the stratum corneum, such as which ingredients are suitable for further increasing the amount of bound water that is strongly bound to components present in the stratum corneum, such as keratin.

[0009] The main objective of this invention is to provide a technology that can enhance bound water within the stratum corneum. [Means for solving the problem]

[0010] The inventors of this invention conducted extensive trial and error in researching components that can enhance bound water in the stratum corneum. As a result, they discovered that by combining specific components from among polyhydric alcohols, even at almost the same concentration as a single component, they could synergistically enhance the amount of bound water in the stratum corneum more than the amount increased by a single component compared to the control, thus completing the present invention.

[0011] In other words, the present invention is as follows. The present invention provides a composition for increasing bound water in the stratum corneum or for suppressing water evaporation in the stratum corneum, comprising component (A) glycerin and component (B) polyglycerin. Furthermore, the present invention provides a bound water enhancing agent or a water evaporation inhibitor within the stratum corneum, which is used to be incorporated into a composition containing component (A) glycerin and component (B) polyglycerin.

[0012] The aforementioned component (B) may be polyglycerin-3. The mass ratio of component (A) and component (B) to be contained or used may be 1:0.01 to 0.5. The aforementioned component (B) may be present in the composition in an amount of 5% by mass or less. The composition may be a cosmetic or a topical skin preparation. The composition may be used in a low-humidity environment. [Effects of the Invention]

[0013] The present invention can provide a technique that can enhance bound water within the stratum corneum. The effects described herein are not necessarily limited, and any of the effects described herein may also be present. [Modes for carrying out the invention]

[0014] The following describes preferred embodiments for carrying out the present invention. The embodiments described below are merely examples of representative embodiments of the present invention, and this should not be interpreted as narrowing the scope of the invention. Furthermore, unless otherwise specified, percentages in this specification are expressed in terms of mass. Also, the upper limit (below) and lower limit (above) of each numerical range (~) can be arbitrarily combined as desired.

[0015] 1. First Embodiment of the Present Invention This first embodiment can provide a composition containing component (A) glycerin and component (B) polyglycerin, more preferably a composition for increasing bound water in the stratum corneum, or a composition for suppressing water evaporation in the stratum corneum. The composition of this first embodiment may be for enhancing bound water or suppressing water evaporation in the stratum corneum of the epidermis, or may be for enhancing bound water or suppressing water evaporation in the epidermis. In addition, in this first embodiment, the (B) polyglycerin is preferably polyglycerin-3. Further, the composition of this first embodiment is preferably a cosmetic or a topical skin preparation.

[0016] 1-1. Component (A) Glycerin Component (A) used in this first embodiment is preferably glycerin. Component (A) glycerin is a kind of trihydric alcohol, also called glycerol (HO-CH2-CH(OH)-CH2-OH)), and commercial products may be used, or those produced by known production methods may be used.

[0017] 1-2. Component (B) Polyglycerin Component (B) used in this first embodiment is preferably polyglycerin. Polyglycerin (for example, triglycerin) is a kind of polyhydric alcohol and contains a plurality of glycerin units in the molecule (HO-(CH2-CH(OH)-CH2-O) , ,

[0018] -H), and commercial products may be used, or those produced by known production methods may be used. The degree of polymerization of polyglycerin (the number of "poly") is not particularly limited, but from the viewpoints of enhancing the improvement of bound water in the stratum corneum and suppressing the improvement of water evaporation, etc., it is preferably 2 to 20, more preferably 2 to 1 The 0, still more preferably 2 to 5, still more preferably 2 to 4, and more preferably 3. In addition, examples of polyglycerin include polyglycerin-2 (also called diglycerin), polyglycerin-3 (also called triglycerin), polyglycerin-4 (also called tetraglycerin), polyglycerin-5 (also called pentaglycerin), etc. One kind or two or more kinds selected from these can be used, and among these, polyglycerin-3 (triglycerin) is preferred.

[0018] The molecular weight of the polyglycerol is not particularly limited, but from the viewpoints of enhancing bound water and improving suppression of water evaporation in the stratum corneum, it is preferably 100 to 2000, more preferably 100 to 800, still more preferably 150 to 400, and even more preferably 150 to 300. The molecular weight can be determined by GPC analysis.

[0019] The IOB value of the polyglycerol is not particularly limited, but from the viewpoints of enhancing bound water and improving suppression of water evaporation in the stratum corneum, it is preferably 0.5 to 5.0, more preferably 1.0 to 5.0, still more preferably 2.0 to 4.0, and even more preferably 3.0 to 4.0. For example, triglycerin (IOB = 3.0), diglycerin (IOB = 3.5), etc. may be mentioned, and one or two selected from these are preferable. The IOB value in the present invention can be determined based on the Organic Conceptual Diagram (Fujita Akira, Prediction of Organic Compounds and Organic Conceptual Diagram, Chemistry Field VOL).11, No.10 (1957) 719 - 715). More specifically, in this Organic Conceptual Diagram, regarding the physicochemical properties of a compound, the degree of physical properties mainly due to the Van der Waals force is defined as "organicity", and the degree of physical properties mainly due to the electrical affinity is defined as "inorganicity" and expressed as a value. The IOB value is an index indicating the balance between inorganicity and organicity, and is expressed as IOB value = inorganicity value / organicity value.

[0020] 1 - 3. The content mass ratio (usage mass ratio) of component (A) and component (B) in the composition in this first embodiment

[0021] The mass ratio (mass ratio used) of component (A) glycerin and component (B) polyglycerin in the composition is not particularly limited, but from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, when the mass of component (A) glycerin is set to 1, the preferred lower limit of component (B) in the composition is preferably 0.005 or more, more preferably 0.01 or more, even more preferably 0.02 or more, even more preferably 0.03 or more, and even more preferably 0.04 or more, and the preferred upper limit of component (B) in the composition is preferably 1 or less, more preferably 0.8 or less, even more preferably 0.5 or less, even more preferably 0.4 or less, even more preferably 0.3 or less, even more preferably 0.2 or less, and even more preferably 0.1 or less. The aforementioned component (A): The aforementioned component (B) is more preferably 1:0.005 to 1, even more preferably 1:0.01 to 0.5, and even more preferably 1:0.02 to 0.1 in the composition, from the viewpoint of improving the enhancement of bound water in the stratum corneum, improving the suppression of water evaporation, and further from the viewpoint of suppressing stickiness.

[0022] The mass ratio (mass ratio used) of component (A) glycerin and component (B) triglycerin in the composition is not particularly limited, but from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, when the mass of component (A) glycerin is set to 1, the preferred lower limit of component (B) triglycerin in the composition is preferably 0.005 or more, more preferably 0.01 or more, even more preferably 0.02 or more, even more preferably 0.03 or more, and even more preferably 0.04 or more, and the preferred upper limit of component (B) triglycerin in the composition is preferably 1 or less, more preferably 0.8 or less, even more preferably 0.5 or less, even more preferably 0.4 or less, even more preferably 0.3 or less, even more preferably 0.2 or less, and even more preferably 0.1 or less. The ratio of component (A) glycerin to component (B) triglycerin in the composition is more preferably 1:0.005 to 1, even more preferably 1:0.01 to 0.5, and even more preferably 1:0.02 to 0.1, from the viewpoint of improving the enhancement of bound water in the stratum corneum, improving the suppression of water evaporation, and further suppressing stickiness.

[0023] 1-4. Total content of component (A) and component (B) in the composition in this first embodiment The total content of component (A) glycerin and component (B) polyglycerin in the composition is not particularly limited, but from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, a more preferable lower limit is preferably 0.5% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 2.5% by mass or more, more preferably 5% by mass or more, more preferably 8% by mass or more, and more preferably 9% by mass or more in the composition. Furthermore, a preferable upper limit is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, even more preferably 20% by mass or less, more preferably 18% by mass or less, more preferably 16% by mass or less, more preferably 15% by mass or less, more preferably 13% by mass or less, and more preferably 12% by mass or less in the composition. A more preferable numerical range for the total content of component (A) and component (B) in the above-mentioned agent is, from the viewpoint of improving the enhancement of bound water in the stratum corneum, improving the suppression of water evaporation, and further from the viewpoint of suppressing stickiness, more preferably 2.5 to 25% by mass, and even more preferably 5 to 15% by mass in the above-mentioned composition.

[0024] The total content of component (A) glycerin and component (B) triglycerin in the composition is not particularly limited, but from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, a more preferable lower limit is preferably 0.5% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 2.5% by mass or more, more preferably 5% by mass or more, more preferably 8% by mass or more, and more preferably 9% by mass or more in the composition. Furthermore, a preferable upper limit is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, even more preferably 20% by mass or less, more preferably 18% by mass or less, more preferably 16% by mass or less, more preferably 15% by mass or less, more preferably 13% by mass or less, and more preferably 12% by mass or less in the composition. A more preferable numerical range for the total content of component (A) glycerin and component (B) triglycerin in the above-mentioned agent is, from the viewpoint of improving the enhancement of bound water in the stratum corneum, improving the suppression of water evaporation, and further from the viewpoint of suppressing stickiness, more preferably 2.5 to 25% by mass, and even more preferably 5 to 15% by mass in the above-mentioned composition.

[0025] 1-5. Content of component (A) in the composition in this first embodiment

[0026] The content of component (A) glycerin in the composition is not particularly limited, but from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, a more preferable lower limit is preferably 0.5% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 2.5% by mass or more, more preferably 5% by mass or more, more preferably 8% by mass or more, and more preferably 9% by mass or more in the composition. Also, a preferred upper limit is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, even more preferably 20% by mass or less, more preferably 18% by mass or less, more preferably 15% by mass or less, more preferably 13% by mass or less, and more preferably 12% by mass or less in the composition. A more preferable numerical range for the content of component (A) glycerin in the agent is, from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, and also from the viewpoint of suppressing stickiness, more preferably 2.5 to 25% by mass, and even more preferably 5 to 15% by mass in the composition.

[0027] 1-6. Content of component (B) in the composition in this first embodiment The content of component (B) polyglycerin in the composition is not particularly limited, but from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, a suitable lower limit is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.25% by mass or more, more preferably 0.3% by mass or more, and more preferably 0.4% by mass or more in the composition. A suitable upper limit is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3.5% by mass or less, even more preferably 3% by mass or less, more preferably 2.5% by mass or less, more preferably 2% by mass or less, more preferably 1.8% by mass or less, more preferably 1.5% by mass or less, more preferably 1.3% by mass or less, and more preferably 1% by mass or less in the composition. A more preferable numerical range for the content of component (B) in the above-mentioned agent is, from the viewpoint of improving the enhancement of bound water in the stratum corneum, improving the suppression of water evaporation, and further from the viewpoint of suppressing stickiness, more preferably 0.2 to 3.5% by mass, and even more preferably 0.3 to 1.5% by mass in the above-mentioned composition.

[0028] The content of component (B) triglycerin in the composition is not particularly limited, but from the viewpoint of improving the enhancement of bound water in the stratum corneum and improving the suppression of water evaporation, a suitable lower limit is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.25% by mass or more, even more preferably 0.3% by mass or more, and even more preferably 0.4% by mass or more in the composition. Furthermore, a suitable upper limit is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3.5% by mass or less, even more preferably 3% by mass or less, even more preferably 2.5% by mass or less, even more preferably 2% by mass or less, even more preferably 1.8% by mass or less, even more preferably 1.5% by mass or less, even more preferably 1.3% by mass or less, and even more preferably 1% by mass or less in the composition. A more preferable numerical range for the content of component (B) triglycerin in the above-mentioned agent is, from the viewpoint of improving the enhancement of bound water in the stratum corneum, improving the suppression of water evaporation, and further from the viewpoint of suppressing stickiness, more preferably 0.2 to 3.5% by mass, and even more preferably 0.3 to 1.5% by mass in the above-mentioned composition.

[0029] 1-7. Applications in this first embodiment The aforementioned components (A) and (B), or their combination or mixture, have the following effects: an effect of increasing or increasing the amount of bound water in the stratum corneum, an effect of suppressing water evaporation in the stratum corneum, and an effect of suppressing water evaporation due to the increase in bound water; and even under low humidity conditions and / or changes in humidity conditions, they have the following effects: an effect of increasing or increasing the amount of bound water in the stratum corneum, an effect of suppressing water evaporation in the stratum corneum, and an effect of suppressing water evaporation due to the increase in bound water. Furthermore, the combination or mixture of components (A) and (B) can exert these various effects in one or two types selected from the group consisting of the stratum corneum, epidermis, and stratum corneum within the epidermis, and can also exert these various effects within the epidermis and / or stratum corneum. Note that an increase in bound water in the stratum corneum means at least an increase in the amount of bound water in the stratum corneum compared to the amount of bound water in the stratum corneum of the control. For example, the amount of bound water in the stratum corneum that occurs when no components are added can be used as a control. As a way to further enhance the amount of bound water in the stratum corneum, by using components (A) and (B), the amount of bound water in the stratum corneum can be increased compared to the amount of bound water in the stratum corneum that occurs when a single component is added.

[0030] Accordingly, the present invention can provide various compositions for use in enhancing bound water in the stratum corneum, suppressing water evaporation in the stratum corneum, suppressing water evaporation due to said enhanced bound water, and enhancing bound water in the stratum corneum, suppressing water evaporation due to said enhanced bound water, under low humidity conditions and / or under changes in humidity conditions, etc. Furthermore, the present invention can also provide compositions, more preferably cosmetics or topical skin preparations, that contain or can be formulated with said components (A) and (B), or said in combination or mixture thereof. Such combination may take the form of a product kit, for example, a product kit consisting of a product containing component (A) and a product containing component (B).

[0031] Furthermore, the components (A) and (B), or their combination or mixture, can also be provided as agents of a third embodiment, intended for addition, formulation, or inclusion in a composition, such as a bound water enhancing agent in the stratum corneum, a water evaporation inhibitor in the stratum corneum, a water evaporation inhibitor due to the enhancement of bound water, and various agents that can be used even in low humidity environments and / or under changes in humidity environments. Examples of compositions to which such agents are added include cosmetics and topical skin preparations, and the composition of the first embodiment can be obtained by incorporating the agents of the third embodiment into the composition.

[0032] Here, water in the stratum corneum can be distinguished into bound water and free water based on its properties, the mobility of water molecules, and its function. Free water is water that is weakly adsorbed to components within the stratum corneum and can move freely, so it evaporates easily as it dries. On the other hand, bound water within the stratum corneum has its mobility restricted by interactions with the hydrophilic parts of coexisting components, so it is strongly bound to components present in the stratum corneum, such as keratin, and is considered to be water that does not easily volatilize even in a dry state. These free water and bound water can be distinguished and detected by thermodynamic methods such as differential thermal analysis, or spectroscopic methods such as near-infrared spectroscopy.

[0033] It has been reported that the stratum corneum retains approximately 33% of its moisture in the form of bound water, and that the intercellular lipids of the stratum corneum retain approximately 13% of that bound water (Non-Patent Literature 1). However, there is still insufficient knowledge regarding components that can enhance the amount of bound water in the stratum corneum, such as which components are suitable for further increasing the amount of bound water that is strongly bound to components present in the stratum corneum, such as keratin.

[0034] However, as a result of diligent research, the inventors have newly discovered that by using a specific combination of component (A) and component (B), even at almost the same concentration as the individual components, the amount of bound water in the stratum corneum can be synergistically increased compared to the amount of bound water in the stratum corneum produced by the individual components. More preferably, they have also newly discovered that even by mixing a small amount of component (B) of about 0.02 to 0.1 parts by mass with 1 part by mass of component (A), the amount of bound water in the stratum corneum can be synergistically increased. Furthermore, since bound water in the stratum corneum is water that does not easily volatilize even in a dry state, the increase in the amount of bound water in the stratum corneum by components (A) and (B) means that, in this embodiment, better moisturizing or skincare effects, prevention and improvement of skin problems, and maintenance of better skin condition can be expected even in low humidity environments and / or under changes in humidity environments. Furthermore, as shown in the [Examples] below, by using a specific combination of component (A) and component (B), it has been confirmed that, in this embodiment, very good results in suppressing moisture evaporation can be obtained in terms of effectiveness and its persistence, even in human trials under low humidity conditions and / or under changes in humidity conditions.

[0035] As a result, component (A) and component (B), or a combination thereof or a mixture thereof, the composition of the first embodiment can prevent, improve, or treat skin problems; provide skincare; maintain or improve the skin in good condition; moisturize the skin; specifically improve moisturizing function; prevent, improve, or treat conditions in which healthy skin becomes dehydrated and dry due to external factors (e.g., low humidity environment, changes in humidity environment) or dry skin, which is one of the skin diseases, and can also moisturize the skin or maintain skin moisture. Examples of skin problems include dry skin, decreased skin moisture, and dry skin. The skin targeted in this embodiment may be healthy skin or skin with a skin disease (sensitive skin, dry skin, etc.). The composition of this first embodiment, comprising component (A) and component (B), or a combination thereof or a mixture thereof, is more preferably used in a low-humidity environment and / or under conditions of humidity change. For example, it may be used for moisturizing or skincare in a low-humidity environment, and it is possible to moisturize the skin or maintain skin moisture even in a low-humidity environment and / or under conditions of humidity change. Therefore, the composition of this first embodiment may be a composition for use in a low-humidity environment and / or under conditions of humidity change.

[0036] Incidentally, the ideal relative humidity for skin is generally considered to be 50-60% RH. Below this level of humidity (less than 50% RH), for example, below 40% RH, skin tends to feel dry, and below 30% RH, even healthy skin is prone to skin problems. Generally, low humidity environments are common due to climate conditions such as season and regional environment. In recent years, the use of air conditioners, stoves, fans, and other equipment and facilities for cooling, heating, air conditioning, and ventilation indoors can also result in low humidity indoors regardless of the season. When adjusting the environment in this way, the room temperature is generally set to around 4-40°C, 10-30°C, or 20-30°C. When using equipment or facilities, if the outside air is low humidity, the indoor humidity may be even lower than that of the outside air.

[0037] Furthermore, changes in humidity can occur in localized areas, such as when removing a mask, or when moving from a bathroom to the outside, as humidity levels can vary from high to low depending on the location or area. This can cause humidity changes to occur throughout the body or in parts of the body. It is known that when humidity levels change from high to low, the amount of moisture decreases further, leading to dryness (see Reference 3: Sato J et al, Arch Dermatol Res (2001) 293:477-480). Thus, changes in humidity levels can easily cause moisture evaporation from the skin, and these changes can sometimes be the cause of skin problems.

[0038] Therefore, users have been requesting cosmetics and topical skin preparations that can prevent the aforementioned skin problems and provide better skincare even in low-humidity environments and / or under changes in humidity, but the reality is that this request has not yet been fully met. However, with this embodiment, it can be used effectively even in such low-humidity environments and / or under changes in humidity, and moreover, the specific combination of components (A) and (B) in this embodiment and its effects were a completely unexpected new discovery even for the inventors.

[0039] In this embodiment, a low-humidity environment is preferably one with a relative humidity lower than 50-60%RH. A preferred upper limit for this relative humidity is more preferably 45%RH or less, even more preferably 40%RH or less, even more preferably 35%RH or less, and even more preferably 30%RH or less. A preferred lower limit is preferably 10%RH or more, even more preferably 15%RH or more, and even more preferably 20%RH or more. A more preferable range in which the effects of this embodiment can be realized is preferably 5-40%RH, and even more preferably 10-35%RH. In such a low-humidity environment, it is easier to obtain the effects that users expect when using this embodiment.

[0040] When evaluating the effect of this embodiment in a low-humidity environment, the evaluation can be performed using the "ratio of moisture content at each elapsed time to the initial moisture content (%)" according to the "Method for evaluating the moisture evaporation suppression effect in a low-humidity environment" in "Test Examples 10-12" of the [Examples] section below. The control should preferably be an uncoated sample. In this case, it is preferable to drop 50 μL of a 10% by mass aqueous solution of the sample onto the pad portion of the patch tester and then attach this patch tester to the subject's skin (preferably the inner forearm), with an attachment time of 10 to 20 minutes (more preferably 15 minutes). The number of subjects is not particularly limited, but 3 or more are preferable, for example, 5 to 10 people. For evaluations in low-humidity environments, the measurement start time (0 minutes) is set to the moment the patch tester is removed, and the measurement times are preferably 10 minutes, 30 minutes, and 60 minutes after removal. At this time, it is preferable to set the temperature and relative humidity in the low-humidity environment to within a predetermined range (e.g., ±1 or ±3%RH) so that there is no fluctuation or the difference in fluctuation is small. In addition, the relative humidity (%RH) and / or temperature (e.g., 20-30°C, 22°C, etc.) in the low-humidity environment may be set as appropriate.

[0041] Ratio of moisture content at each time point to initial moisture content (%) = {(average moisture content at each time point) / (average moisture content of bare skin before sample application)} × 100 "Average skin moisture content before sample application" refers to the average value obtained by dividing the sum of each subject's "skin moisture content before sample application" by the total number of subjects. "Average moisture content at each time point" refers to the average value obtained by dividing the sum of each subject's "average moisture content at each time point" by the total number of subjects.

[0042] In this embodiment, "under a change in humidity environment" includes at least one period under a high humidity environment and one period under a low humidity environment, and is characterized by a change in humidity environment, such as from a high humidity environment to a low humidity environment, but is not particularly limited. For example, it may be a localized change in humidity environment on the skin or face caused by putting on or taking off a mask, or it may be a change in humidity environment of the entire body or a part of the body (e.g., face or scalp) due to movement or change to a different humidity environment, such as when going from a bathroom to outside the bathroom. In this embodiment, even in situations where the humidity environment changes in a short period of time due to putting on or taking off a mask, movement, changes in airflow, etc., and even when changes such as "high humidity environment → low humidity environment" or "low humidity environment → high humidity environment" occur in combination or repeatedly, and even in a low humidity environment within a change in humidity environment, it is easy to obtain the effects of this embodiment as expected by the user. Furthermore, "under a change in humidity environment" in this embodiment may include one or more identical or different "periods under a high humidity environment" and one or more identical or different "periods under a low humidity environment". The duration of the high-humidity environment is not particularly limited, but a suitable lower limit is preferably 1 minute or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, and a suitable upper limit is 180 minutes or less, more preferably 120 minutes or less, 80 minutes or less, or 30 minutes or less. Similarly, the duration of the low-humidity environment is not particularly limited, but a suitable lower limit is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, and a suitable upper limit is preferably 300 minutes or less, more preferably 260 minutes or less, even more preferably 200 minutes or less, even more preferably 180 minutes or less, 120 minutes or less, or 60 minutes or less. Within at least these durations, the effects of this embodiment can be better exhibited or maintained.

[0043] Furthermore, the difference in humidity environmental change (%RH) can be calculated using "relative humidity (high humidity) - relative humidity (low humidity)". If the humidity environmental change includes one or more identical or different "periods under high humidity" and one or more identical or different "periods under low humidity", the difference in humidity environmental change (%RH) when the humidity drops from "high humidity" to "low humidity" between adjacent "periods under high humidity" and "periods under low humidity" may be calculated, and the average value obtained based on these may be used as the difference in humidity environmental change (%RH) (for example, see <Test Examples 10-12><Evaluation Method for Suppressing Water Evaporation Under Humidity Environmental Change><Measurement Method> below). The definition of "low humidity" in the humidity environmental change can be appropriately adopted from the explanation of "low humidity" in the above "low humidity environment". Furthermore, "high humidity" in the humidity environmental change preferably refers to humidity higher than the aforementioned "low humidity" and may include relative humidity of 50-60%RH.

[0044] Furthermore, the difference in humidity environmental change (%RH) can be calculated using "relative humidity (high humidity) - relative humidity (low humidity)". If there are multiple sets of "periods under high humidity and periods under low humidity", the average value of high humidity from each period under high humidity and the average value of low humidity from each period under low humidity can be calculated, and the difference between these average values ​​may be used. The definition of "low humidity" in humidity environmental change can be appropriately adopted from the explanation of "low humidity" in the above "low humidity environment". In addition, "high humidity" in humidity environmental change preferably refers to humidity higher than the aforementioned "low humidity" and may include relative humidity of 50-60%RH.

[0045] In this embodiment, the preferred lower limit of the difference in humidity change under humidity environmental changes is preferably 5%RH or higher, more preferably 10%RH or higher, and even more preferably 15%RH or higher. The preferred upper limit is preferably 60%RH or lower, more preferably 50%RH or lower, even more preferably 40%RH or lower, more preferably 30%RH or lower, and even more preferably 25%RH or lower. The more preferred range for the difference in humidity change is preferably 10-30%RH, and even more preferably 15-25%RH. In the difference in humidity change under said humidity environmental changes, the low humidity setting is more preferably 30%RH, and the high humidity setting is more preferably 50%RH. Under said humidity environmental changes, it is easier to obtain the effects that the user expects when using this embodiment.

[0046] When evaluating the effect of this embodiment under changes in humidity conditions, the evaluation can be performed using the "ratio of moisture content at each elapsed time to the initial moisture content (%)" according to the "Method for evaluating the effect of suppressing moisture evaporation under changes in humidity conditions" in "Test Examples 10-12" of the [Examples] section below. The control should preferably be an uncoated sample. In this case, the application of the patch tester, the application time, and the number of subjects can be determined using the method described in "When evaluating this embodiment under low humidity conditions" above. When evaluating the effects of this embodiment under changes in humidity conditions, it is desirable to evaluate in the following ways: "high humidity → low humidity," "low humidity → high humidity," or in combinations thereof such as "low humidity → high humidity → low humidity," or by repeating these cycles. It is preferable to set a predetermined period for each of these conditions, preferably 10 to 240 minutes, more preferably 10 to 200 minutes. The period under high humidity is preferably 10 to 120 minutes, and the period under low humidity is preferably 1 to 200 minutes, more preferably 30 to 200 minutes. Furthermore, it is desirable to measure the moisture content of a predetermined area of ​​skin under low humidity conditions, which are included in the changes in humidity conditions, as this makes it easier to evaluate the transpiration effect and bound water enhancement effect within the stratum corneum under low humidity conditions during the changes in humidity conditions. For example, it is desirable to evaluate the sample by including the following: having a subject who is present in a first high humidity environment be placed in a first low humidity environment for 5 to 20 minutes (preferably as an acclimatization period); further, in the first low humidity environment, applying a patch tester to the subject's skin (preferably the inner forearm) for 10 to 20 minutes; starting from the time the patch tester is removed (0 minutes), having the subject present in the first low humidity environment for 0 to 60 minutes (preferably as a measurement period), in the first high humidity environment for 60 to 165 minutes (preferably as an acclimatization period), and in the second low humidity environment for 165 to 360 minutes (preferably as an acclimatization period of 10 to 20 minutes followed by a measurement period of 175 to 185 minutes); and measuring the moisture content of the subject's skin in the area where the sample was in contact with the patch tester; and the evaluation period is from 0 minutes to 360 minutes from the start. A more preferable specific evaluation procedure would involve acclimatizing the subject's skin to a first low-humidity environment for 15 minutes, contacting the sample with the skin for 10-20 minutes in the first low-humidity environment, measuring the skin's moisture content for 0-60 minutes in the first low-temperature environment (measurement times e.g., 0, 30, 60 minutes), then acclimatizing the subject's skin to a first high-humidity environment for 100-110 minutes, acclimatizing the subject's skin to a second low-humidity environment for 10-20 minutes, and after acclimatization, measuring the skin's moisture content for 0-180 minutes in the second low-humidity environment (measurement times e.g., 0, 60, 90, 180 minutes). In the evaluation under changes in humidity conditions in this invention, the patch tester may be acclimatized in a high-humidity environment from the time of removal, and then the humidity environment may be changed to a low-humidity environment. Alternatively, the patch tester may be acclimatized in a low-humidity environment from the time of removal, and then further acclimatized in a high-humidity environment before changing the humidity environment to a low-humidity environment. Furthermore, the evaluation may be performed with the high-humidity environment set to 22°C and 50%RH, and the low-humidity environment set to 22°C and 30%RH, and these temperature and humidity conditions may be changed as appropriate.

[0047] Furthermore, as another aspect of this first embodiment, a product kit comprising a product containing a composition containing component (A) and a product containing a composition containing component (B), or a product containing component (A) and a product containing component (B) may be used in combination, either simultaneously or separately. Alternatively, the composition of this first embodiment may be prepared by simultaneously or separately mixing component (A) and component (B) contained in the product kit, or a product kit capable of such preparation may be provided. For example, a practitioner or end-user may mix component (A) and component (B) before use and apply the mixture to the skin, or they may apply component (A) and component (B) to the skin simultaneously or separately and mix them on the skin to prepare the composition of this first embodiment.

[0048] Furthermore, another aspect of this first embodiment is the provision of components (A) and (B), their combination, a mixture of components (A) and (B), or an agent containing components (A) and (B), or the use thereof, for the purposes described above, such as increasing bound water in the epidermis and / or stratum corneum, suppressing water evaporation, suppressing water evaporation by said increased bound water, and use on the skin in low humidity environments and / or under changes in humidity environments, and these can be included in or incorporated into various agents or compositions.

[0049] Furthermore, as another aspect of this first embodiment, component (A) and component (B), or a combination thereof or a mixture thereof, the composition of this first embodiment can be used in the above-mentioned methods for increasing bound water in the epidermis and / or stratum corneum, methods for suppressing water evaporation, methods for suppressing water evaporation by increasing bound water, etc., or as active ingredients in these methods.

[0050] Furthermore, as another aspect of this first embodiment, component (A) and component (B), or the agent of this third embodiment, can be used to manufacture various agents or compositions having the above-mentioned effects of increasing bound water in the epidermis and / or stratum corneum, inhibiting water evaporation, and these effects under low humidity conditions and / or changes in humidity conditions. They can also be used to manufacture various agents or compositions for the above-mentioned purposes of increasing bound water in the epidermis and / or stratum corneum, inhibiting water evaporation, and increasing bound water in the epidermis and / or stratum corneum and inhibiting water evaporation under low humidity conditions and / or changes in humidity conditions.

[0051] Furthermore, this embodiment may be used for therapeutic purposes or for non-therapeutic purposes. "Non-therapeutic purposes" is a concept that does not include medical procedures (for example, procedures performed by a doctor), that is, procedures performed on the human body for therapeutic purposes. Examples of non-therapeutic purposes include cosmetic treatment and massage.

[0052] Furthermore, in this embodiment, "prevention" means preventing or delaying the onset of symptoms or diseases in the target area, or reducing the risk of developing symptoms or diseases in the target area. In this technology, "improvement" means improving or maintaining the condition of a disease, symptoms, or state in the target area; preventing or delaying deterioration; reversing, preventing, or delaying progression.

[0053] Furthermore, this embodiment can be applied to humans and non-human animals (e.g., pets, livestock, non-human mammals, etc.). Of these, humans and pets are preferred, and humans are more preferred.

[0054] <Optional ingredients> Furthermore, the agent or composition containing component (A) and component (B), or component (A) and component (B), may optionally contain or blend components commonly used in various formulations such as cosmetics, quasi-drugs, pharmaceuticals, and other topical skin preparations, to the extent that the effects of this technology are not impaired. Examples of such components include preservatives, cell activators, antioxidants, humectants, UV inhibitors, solvents (water, alcohols, etc.), oils, surfactants, thickeners, powders, chelating agents, pH adjusters, emulsifiers, stabilizers, colorants, glossing agents, flavoring agents, deodorizing agents, excipients, binders, disintegrants, lubricants, diluents, osmotic pressure adjusters, fragrances, and the like. One or more of these may be appropriately selected and used. The form of the agent in this embodiment is not particularly limited and may be in any form, such as liquid, paste, gel, solid, or powder.

[0055] Furthermore, the composition of this embodiment can be obtained by known manufacturing methods. The cosmetics and topical skin preparations of this embodiment may specifically include, for example, basic cosmetics such as oil-in-water emulsions, water-in-oil emulsions, lotions, creams, toners, face masks, liquid foundations, serums, face masks, all-in-one gels, sunscreens, and cleansers; makeup cosmetics such as makeup bases, BB creams, foundations, blushes, and lipsticks; hair cosmetics such as hair tonics, hair tonics, shampoos, and conditioners; and any other form such as dispersions, ointments, liquids, aerosols, patches, poultices, and liniments. Cosmetics and topical skin preparations for use on the skin that are expected to have moisturizing and emollient effects are preferred.

[0056] 2. Second Embodiment According to the Present Invention

[0057] This second embodiment provides a method for increasing bound water in the epidermis and / or stratum corneum and suppressing water evaporation, using component (A) and component (B), or a combination thereof or a mixture thereof, the composition of this first embodiment, etc., on the skin, and a method for increasing bound water in the epidermis and / or stratum corneum and suppressing water evaporation, etc., even in low humidity environments and / or under changes in humidity environments. The aforementioned use is not particularly limited, but is preferably by application, rubbing, massage, spraying, etc., to the skin. The area of ​​application to the skin is not particularly limited as long as it is skin, but is preferably one or more selected from the whole body, scalp, face, arms, legs, hands, etc. Furthermore, the user may be a professional practitioner such as a massage therapist, esthetician, or beautician, or a general user or end user. The preferred mass ratio of component (A) and component (B) is 1:0.01 to 0.5. Furthermore, the amount of component (A) used or applied to the target is not particularly limited, but when a 10% aqueous solution of component (A) and component (B) is prepared and 1 g of the aqueous solution is used or applied, 0.067 to 0.099 g is preferred, 0.070 to 0.090 g is more preferred, and 0.086 to 0.090 g is even more preferred. Furthermore, the amount of component (B) used or applied to the target is not particularly limited, but when a 10% aqueous solution of component (A) and component (B) is prepared and 1 g of the aqueous solution is applied, 0.001 to 0.033 g is preferred, 0.010 to 0.030 g is more preferred, and 0.010 to 0.014 g is even more preferred.

[0058] In describing the method of this second embodiment, explanations of components (A), components (B), their respective contents, their respective mass percentages, manufacturing methods, their respective configurations, their respective methods, and their respective terms, which overlap with the explanations in "1. First Embodiment According to the Present" and "3. Third Embodiment According to the Present" above, will be omitted as appropriate. However, the explanations in "1. First Embodiment According to the Present" and "2. Third Embodiment According to the Present" below also apply to this second embodiment and can be adopted as appropriate. Content and mass percentage may be expressed as usage amount and usage mass percentage.

[0059] 3. Third Embodiment According to the Present Invention This third embodiment can provide a bound water enhancer or moisture evaporation inhibitor for use in a composition, and a bound water enhancer or moisture evaporation inhibitor for use in low humidity environments and / or under changes in humidity environments. Furthermore, the agent of this second embodiment may contain (A) glycerin and (B) polyglycerin. Polyglycerin-3 is preferred for (B) polyglycerin. It is preferable that the mass ratio of component (A) and component (B) used in the agent is 1:0.01 to 0.5. It is preferable that component (B) is added so that it is 5% by mass or less in the composition. It is preferable that the total amount of component (A) and component (B) is added so that it is 2.5 to 25% by mass in the composition.

[0060] In describing the agent of this third embodiment, explanations of component (A), component (B), their respective contents, their respective mass percentages, manufacturing methods, their respective compositions, their respective methods, and their respective terms, which overlap with the explanations of "1. First Embodiment According to the Present Invention" and "2. Second Embodiment According to the Present Invention" described above, will be omitted as appropriate. However, the explanations of "1. First Embodiment According to the Present Invention" and "2. Second Embodiment According to the Present Invention" described above also apply to this third embodiment and can be adopted as appropriate. Content and mass percentage may be expressed as usage amount and usage mass percentage. Furthermore, a composition containing the agent of this third embodiment, preferably a cosmetic or a topical skin preparation, can be provided. It is preferable to include or blend the agent of this third embodiment in such a way that it contains or contains the same amount and mass ratio of components (A) and (B) as described in "1. First Embodiment of the Present Invention" in the aforementioned composition.

[0061] Furthermore, this technology can also employ the following configurations. • [1] A composition containing component (A) glycerin and component (B) polyglycerin. The composition is preferably a composition for increasing bound water in the stratum corneum, or a composition for suppressing water evaporation in the stratum corneum. The composition is more preferably a composition for use in a low humidity environment and / or under changes in humidity, and the low humidity is preferably a relative humidity lower than 50-60%RH, and more preferably a relative humidity of 20-40%RH or less, and is more preferably used at room temperature (e.g., 4°C-40°C). • [2] The composition according to [1], wherein the component (B) polyglycerin is polyglycerin-3. • [3] The composition according to [1] or [2], wherein the mass ratio of component (A) and component (B) in the composition is 1:0.01 to 0.5. • [4] The composition described in any one of [1] to [3] above, wherein the composition is preferably a cosmetic or a topical skin preparation. [5] The composition described in [4] above, which is used to enhance bound water in the epidermis and / or stratum corneum, or to suppress water evaporation in the epidermis and / or stratum corneum, etc. • [6] The composition described in [5] above, for use in a low humidity environment and / or under changes in humidity. • [7] The composition according to any one of [1] to [6], wherein the mass ratio of component (A) and component (B) in the composition is 1:0.01 to 0.5. • [8] The composition according to any one of [1] to [7], wherein component (B) is present in an amount of 5% by mass or less in the composition. • [9] A bound water enhancer or water evaporation inhibitor in the stratum corneum, used for incorporation into a composition containing component (A) glycerin and component (B) polyglycerin. A composition containing said agent is preferred in the form of a cosmetic or topical skin preparation. •

[10] A product kit comprising (i) a product containing a composition containing component (A) glycerin and (ii) a product containing a composition containing component (B) polyglycerin. It is preferable to mix the composition (i) and the composition (ii) and apply them to the skin. •

[11] A composition according to any one of [1] to [9] above, or a product kit according to

[10] above, for use in low humidity environments and / or under changes in humidity environments, more preferably for use in moisturizing or skin care in low humidity environments and / or under changes in humidity environments. •

[12] A composition or product kit according to any one of [1] to [8] above, or according to [9] above, used to prevent, improve, or treat dry skin in low humidity environments and / or under changes in humidity environments, for the purpose of providing moisture to the skin or maintaining skin moisture in low humidity environments and / or under changes in humidity environments, thereby preventing or improving the drying of healthy skin in low humidity environments. The product may use a container for containing the composition, a sheet for impregnating the composition, a packaging film, etc.

[0062] •

[13] (A) Glycerin and (B) Polyglycerin, used to enhance bound water in the epidermis and / or stratum corneum, or to suppress water evaporation in the epidermis and / or stratum corneum. Preferably, component (A) is glycerin and / or component (B) is polyglycerin-3. Furthermore, it is more preferable to use it in a low humidity environment and / or under changes in humidity. •

[14] For the production of agents or compositions for increasing bound water in the epidermis and / or stratum corneum, or for suppressing water evaporation in the epidermis and / or stratum corneum, The composition is more preferably a cosmetic or topical skin preparation. The preparation or composition is more preferably used in low humidity environments and / or under changes in humidity. •

[15] A method for increasing bound water in the epidermis and / or stratum corneum or for suppressing water evaporation, using any one of the compositions, product kits, or agents described in [1] to

[12] above, or using component (A) glycerin and component (B) polyglycerin. The method is more preferably characterized by being used in a low humidity environment and / or under changes in humidity. [Examples]

[0063] The present technology will be described in more detail below based on examples and other relevant information. The examples and other relevant information described below are merely representative examples of the present technology and should not be interpreted as narrowing the scope of the present technology.

[0064] <Test Examples 1 to 9>

[0065] The water content (mg) of bound water in the stratum corneum determined for each sample of Test Examples 1 to 9 and according to the following <Method for Measuring the Water Content of Bound Water in the Stratum Corneum> is shown in Table 1.

[0066] Raw material Glycerin: ECOCEROL (manufactured by ECOGREEN OLEOCHMICALS) Polyglycerin-3 (triglycerin): PGL-S (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.). The molecular weight of polyglycerin-3 was 240 by the above-described GPC analysis, and the IOB value was 3.0 by the method for obtaining the IOB value described above. Dipropylene glycol (manufactured by ADEKA) 1,3-Butylene glycol (manufactured by Daicel)

[0067] The following were used as the stratum corneum sheets. Human stratum corneum sheet (manufactured by BIOPREDIC International, product number: STR002, product name: Human Stratum Corneum, overview: derived from the abdomen) In addition, when a stratum corneum sheet without addition of a sample as in Test Example 1 is used as a control, and this is taken as 100%, and when determining the enhancement of bound water in comparison with this control, a sheet prepared by culturing (for example, a two-dimensional stratum corneum sheet, a three-dimensional stratum corneum sheet, etc.) the stratum corneum peeled from human skin by a known method may be used.

[0068] <DSC device> DSC device: DSC7020 (manufactured by Hitachi High-Tech Science Corporation) Sample pan: AL chromate-treated simple sealed container[[ID=......]] Measurement mode: None

[0069] [[ID=......]] <Method for Measuring the Water Content of Bound Water in the Stratum Corneum> A commercially available human stratum corneum sheet was prepared to a size of 1 cm x 1 cm, and a dried stratum corneum sheet was obtained. Each aqueous solution was prepared as shown in Table 1, according to Test Examples 2 to 9, and these were used as the solutions for each test example. For example, the "9.5% glycerin + 0.5% triglycerin-containing aqueous solution" in Test Example 7 can be obtained by mixing 9.5 g of glycerin, 0.5 g of triglycerin, and the remainder water to a total volume of 100 g. Each aqueous solution for each test example was added to a sterile petri dish (10 cm in diameter) to approximately 80% capacity. The stratum corneum sheet was then placed in the petri dish, sealed, and immersed for 20 minutes. After immersion, the sheet was placed on a board, and the moisture on the surface of the stratum corneum sheet was wiped off by sandwiching it between two Kimwipes (manufactured by Nippon Paper Crecia Co., Ltd.) and pressing with the index finger for 3 seconds. The wiped stratum corneum sheets were placed in a pan (a simple sealed container treated with Al chromate), and the first DSC measurement followed by the second DSC measurement was performed using a DSC measuring device and DSC analysis software, as shown below. In the first DSC measurement, the amount of frozen water (mass: mg) in the stratum corneum sheet containing the sample was determined, and in the second DSC measurement, the mass (mg) of the stratum corneum sheet after all the water in the sample had evaporated was determined. DSC measurements were performed sequentially for each sample from Test Examples 1 to 9. The amount of frozen water (free water) (mg) was calculated from the enthalpy of fusion during the heating process obtained using a DSC measuring device, and the amount of unfreezed water (bound water) (mg) was calculated by subtracting the amount of frozen water (mg) from the total amount of water (mg) in the stratum corneum sheet (References 1: OKA T et al, Polymer 41(16):6055-6059 and 2: Imokawa G et al, Exogenous Dermatology 3(2):81-98).

[0070] <First DSC measurement: Measurement to determine the amount of frozen water> In this test, since the free water contained in the stratum corneum sheet is weakly bound by the components within the stratum corneum (mainly stratum corneum cells) and becomes frozen water, the amount of frozen water (mg) was regarded as the amount of free water. Measurement temperature range: Temperature setting for heating from -60°C to 25°C after cooling from 25°C to -60°C, scanning rate: DSC measurement was performed at 5°C / min, and the amount of frozen water present in the stratum corneum sheet was determined from the following formula and taken as the "amount of frozen water (mg)". Amount of frozen water (mg) = {Melting peak area (mJ / mg) × Mass of stratum corneum sheet after sample treatment (mg)} / Standard ΔH of water (mJ / mg) Note that the amount of frozen water (mg) in the stratum corneum sheet was determined using DSC analysis software (Standard analysis) based on the melting peak area (melting enthalpy) of water during the heating process in the obtained DSC chart. The standard melting enthalpy of water at this time is 333.1 (mJ / mg). Also, the mass of the stratum corneum sheet after sample treatment (mg) is the value obtained by subtracting the mass (mg) of the dry stratum corneum sheet before treatment from the mass (mg) of the stratum corneum sheet after dipping each aqueous solution of each test example for 20 minutes and wiping it off.

[0071] <Second DSC measurement: Method for determining the total amount of water in the stratum corneum sheet> After the completion of the first DSC measurement A, several holes were made with a needle at the upper part of the sample pan, the sample pan was set in the DSC, the temperature range was heated from 25°C to 120°C, and the measurement was performed at a scanning rate of 5°C / min. The total amount of water evaporated from the stratum corneum sheet was determined by the measurement and taken as the "amount of water in the stratum corneum (mg)".

[0072] <Calculation method of unfrozen water by DSC> In this test, since the bound water contained in the stratum corneum sheet is strongly bound to the components within the stratum corneum (stratum corneum cells, intercellular lipids) and the sample substances in Table 1 that have penetrated into the stratum corneum and becomes unfrozen water, the amount of unfrozen water (mg) was regarded as the amount of bound water (mg). (1) The frozen water was determined by the above first DSC measurement. Amount of frozen water (mg) = {Melting peak area (mJ / mg) × Weight of stratum corneum sheet after treatment (mg)} / Standard ΔH of water (mJ / mg) (2) The amount of water in the stratum corneum was determined by the above second DSC measurement. (3) The amount of nonfreezing water was calculated as follows: Amount of nonfreezing water (mg) = Amount of water in the stratum corneum (mg) - Amount of freezing water (mg) As an example, the amount of frozen water determined by the first DSC measurement was 0.146 mg, and the total amount of water in the stratum corneum determined by the second DSC measurement was 0.371 mg. From this, the amount of non-freezing water was calculated as 0.371 mg - 0.146 mg = 0.225 mg. The total amount of water in the stratum corneum determined by the second DSC measurement (0.371 mg) was calculated from [mass of stratum corneum sheet after sample treatment 0.825 mg] - [mass of stratum corneum sheet after all water has completely evaporated due to the heating in the second DSC measurement (mg) 0.454 mg].

[0073] [Table 1]

[0074] <Result> In each of the test examples 2-9, when compared to water (no sample added) in test example 1 as a control, the bound water content in the stratum corneum was increased in all cases. Among these, the aqueous solution containing 9.5% glycerin + 0.5% triglycerin in test example 5, which uses both glycerin and triglycerin, showed a particularly remarkable effect, with a bound water increase rate of more than 1.8 times compared to using water alone in test example 1. Furthermore, when comparing the triglycerin-added test example 5 with the triglycerin-free test example 2, the bound water increase rate in test example 5 was approximately 1.4 times that of test example 2, also showing a particularly remarkable effect. In other words, it was suggested that using a mixed aqueous solution of 10% glycerin with a small amount of triglycerin added resulted in more than double the amount of antifreeze water compared to glycerin alone. Furthermore, since the bound water within the stratum corneum is strongly bound to the stratum corneum, it can be made into water that does not freeze, and the amount of non-freezing water obtained within the stratum corneum can be considered as the amount of bound water within the stratum corneum. Therefore, it was suggested that by using a mixed aqueous solution of glycerin with a small amount of triglycerin added, the amount of bound water in the stratum corneum can be increased or enhanced to more than double the amount of glycerin alone.

[0075] Furthermore, the aqueous solutions of Test Examples 5, 7, and 9 showed almost the same level of non-stickiness as the 10% glycerin-containing aqueous solution of Test Example 2. On the other hand, the 24% glycerin-containing aqueous solution of Test Example 3 showed worse non-stickiness compared to the 10% glycerin-containing aqueous solution of Test Example 2, and was sticky. From Test Example 5, it was found that using polyglycerins such as triglycerin in combination with glycerin provides a very excellent effect of enhancing bound water in the stratum corneum while maintaining non-stickiness. In this embodiment, the non-stickiness was assessed by one expert panelist who applied 0.5 mL of the sample to the back of their hand and evaluated it on a three-point scale: "Same as, No stickiness compared to, 10% glycerin-containing aqueous solution" using the 10% glycerin-containing aqueous solution as a baseline. Furthermore, when performing an absolute evaluation of the absence of stickiness in this embodiment, it can be done in accordance with Test Method 3: Absence of Stickiness in the [Examples] described in Japanese Patent Application Publication No. 2018-39789.

[0076] <Test Examples 10-12> For Test Example 11, a 10% by mass aqueous solution containing glycerin was used as the sample, and for Test Example 12, a 9.5% by mass glycerin + 0.5% by mass triglycerin aqueous solution was used as the sample. For each, the following evaluations were performed: <Evaluation of moisture evaporation suppression effect under low humidity conditions> and <Evaluation of moisture evaporation suppression effect under changes in humidity conditions>. Test Example 10, the control, was left uncoated. The results of these evaluations are shown in Tables 2 and 3.

[0077] <Evaluation of the effect of suppressing water evaporation in low humidity environments> Table 2 shows the ratio (%) of the moisture content at each time point to the initial moisture content for each sample in Test Examples 10-12, as determined according to the <Method for Evaluating the Moisture Evaporation Suppression Effect in Low Humidity Environments> described below.

[0078] <Method for evaluating the effect of suppressing water evaporation in low-humidity environments> The moisture evaporation suppression effect in a low-humidity environment was confirmed using the uncoated sample from Test Example 10 and each basic composition (each sample) from Test Examples 11-12. The low-humidity environment was assumed to be a condition where the outside air is drier than 50-60% RH relative humidity, similar to winter in the Kanto region of Japan, and the indoor temperature (approximately 20-30°C) is controlled by an air conditioner. Measurements were taken at 22°C and 30% RH relative humidity. Furthermore, to simulate prolonged exposure to the aforementioned low-humidity environment, the measurement time was set to 60 minutes, and measurements were taken on nine Japanese male and female subjects (in their 20s to 40s).

[0079] <Measurement method> The inner forearm of each subject, which is the measurement site, was washed with bar soap and allowed to acclimate for 15 minutes at 22°C and 30% RH. Then, the initial moisture content of the bare skin before application was measured for each of the samples in Test Examples 11 and 12. Next, 50 μL of each of the samples in Test Examples 11 and 12 was dropped onto the pad portion of a patch tester (manufactured by Torii Pharmaceutical Co., Ltd.). These patch testers containing each of Test Examples 11 and 12 were then applied to the inner forearm of each subject for 15 minutes, while Test Example 10 was left unapplied (unapplied) for 15 minutes. After 15 minutes, the patch testers containing each sample (Test Examples 10-12) were removed, and the moisture content of the skin at the parts (measurement sites) that were in contact with the pad portion of each sample on the inner forearm was measured 10 minutes, 30 minutes, and 60 minutes after removal using SKICON (manufactured by Yayoi Co., Ltd.: constant pressure sensor probe contact, high-frequency conductance conversion method). The water evaporation inhibitory effect was evaluated based on the ratio of the water content at each time point to the initial water content. Here, the ratio of the moisture content at each time point to the initial moisture content (%) was calculated as follows. Ratio of moisture content at each time point to initial moisture content (%) = {(average moisture content at each time point) / (average moisture content of bare skin before sample application)} × 100 The average water content at each time point is calculated by summing the water content of each subject at each time point and then dividing each total water content by the total number of subjects. In this study, there were 9 subjects in total. The average skin moisture content before sample application is calculated by summing the skin moisture content of each subject before sample application and dividing by the total number of subjects. In this study, there were 9 subjects in total. Ideally, the total number of subjects should be at least three.

[0080] [Table 2]

[0081] As shown in Table 2: <Evaluation of moisture evaporation suppression effect in low humidity environments>, in Test Example 10, where no sample was applied, the change from the initial moisture content remained at ±10% regardless of the passage of time, whereas Test Examples 11 and 12 showed higher moisture content than Test Example 10 at each time point. Furthermore, comparing Test Examples 11 and 12, Test Example 12, which contains a small amount of triglycerin in 10% glycerin, showed a higher moisture content relative to the initial value at each time point, suggesting that it suppresses moisture evaporation over a long period of time even in low humidity environments, confirming that it exhibits a stronger moisture evaporation suppression effect.

[0082] <Evaluation of the effect of suppressing water evaporation under changes in humidity conditions> Furthermore, the relationship between humidity changes and moisture content has been studied, and it is known that moisture content decreases (dries out) more when the environment changes from high humidity to low humidity (see Reference 3: Sato J et al, Arch Dermatol Res (2001) 293:477-480). Therefore, using the samples from Test Examples 10 to 12, the moisture content ratio (%) at each time point to the initial moisture content under the humidity environment change, determined according to the <Method for Evaluating the Moisture Evaporation Suppression Effect under Humidity Environment Changes> below, is shown in Table 3.

[0083] <Method for evaluating the effect of suppressing water evaporation under changes in humidity conditions> After performing the <Evaluation of the moisture evaporation suppression effect in low humidity environments> described above, the moisture evaporation suppression effect under changes in humidity environments was further confirmed on the skin portions of the untreated portion of Test Example 10 and the portions treated with the basic compositions of Test Examples 11-12, according to the <Measurement Method> described below. The change in humidity environment from high humidity to low humidity is not particularly limited, but to simulate situations where one actually feels dryness, such as when removing a mask after wearing it or when leaving a bathroom, measurements were taken when the humidity environment changed from 22°C and 50% RH relative humidity to 22°C and 30% RH relative humidity. Furthermore, to simulate humidity changes in real life, the measurement time after the humidity change was set to 180 minutes, and measurements were taken on nine Japanese male and female subjects (in their 20s to 40s).

[0084] <Measurement method> In the <Method for Evaluating the Moisture Evaporation Inhibition Effect in Low Humidity Environments> described above, measurements were taken for 60 minutes in a low humidity environment of 22°C and 30% RH relative humidity, followed by 105 minutes of acclimatization in a 22°C, 50% RH environment. Subsequently, considering the possibility that the overall moisture content might be measured higher if measured immediately after the humidity change, acclimatization was performed for 15 minutes in a 22°C, 30% RH environment. Then, the moisture content of the skin in the same area on the inner forearm where the moisture content was measured in the <Method for Evaluating the Moisture Evaporation Inhibition Effect in Low Humidity Environments> described above was measured at 0 minutes, 60 minutes, 90 minutes, and 180 minutes after acclimatization, using SKICON (manufactured by Yayoi Co., Ltd.). The moisture evaporation inhibition effect was evaluated from the ratio of the moisture content at each time to the initial moisture content. The initial moisture content refers to the initial moisture content of the bare skin before application of each sample from Test Examples 11 and 12, after washing the inner forearm, the measurement site of the subject, with solid soap and acclimatizing it for 15 minutes at 22°C and 30% RH, as described in the <Method for Evaluating the Moisture Evaporation Inhibition Effect in Low Humidity Environments> above, and then allowing it to acclimate. Here, the ratio of the moisture content at each time point to the initial moisture content (%) was calculated using the method described above. Furthermore, if the humidity environment changes at this time, and the first low humidity environment is 30%RH, the first high humidity environment is 50%RH, and the second low humidity environment is 30%RH, and the difference in humidity environment change between adjacent "periods in a high humidity environment" and "periods in a low humidity environment" is calculated as going from a "high humidity environment" to a "low humidity environment", then the difference in humidity environment change is 20%RH (50%RH in the first high humidity environment - 30%RH in the second low humidity environment). If the second high humidity environment is 60%RH followed by the third low humidity environment is 20%RH, then the difference is 40%RH (60%RH in the second high humidity environment - 20%RH in the third low humidity environment), and the average of these is (20%RH + 40%RH) / 2, which is 30%RH. Therefore, the range of humidity environment change differences in which the effects of this embodiment can be achieved may be 20-40%RH.

[0085] [Table 3]

[0086] As shown in Table 3: <Evaluation of moisture evaporation suppression effect under humidity environmental changes>, in Test Example 10, where no sample was applied, the change from the initial moisture content remained within ±10% regardless of the passage of time, whereas Test Examples 11 and 12 showed higher moisture content than Test Example 10 at each time point. Furthermore, comparing Test Examples 11 and 12, Test Example 12, which contains a small amount of triglycerin in 10% glycerin, showed a higher moisture content relative to the initial value at each time point. This confirmed that it exerted a stronger and more sustained moisture evaporation suppression effect even under humidity environmental changes from high humidity to low humidity, and even over a longer period of 3 to 6 hours after application.

[0087] From this, it was confirmed that components that enhance bound water in the stratum corneum have an excellent ability to suppress water evaporation from the stratum corneum, even under low humidity conditions and / or under changes in humidity conditions. Thus, it was confirmed that components that enhance bound water in the stratum corneum, namely component (A) glycerin and component (B) polyglycerin (preferably polyglycerin-3), their combination, or mixture thereof, have an excellent moisturizing or skincare effect even under low humidity conditions and / or under changes in humidity conditions, and can better prevent or improve the drying of healthy skin under low humidity conditions and / or under changes in humidity conditions.

[0088] The inventors have discovered that by using a specific combination of polyhydric alcohols, it is possible to synergistically enhance the amount of bound water in the stratum corneum more effectively than with individual components, suppress moisture evaporation even in low humidity environments and / or under changes in humidity, and furthermore, exhibit excellent moisturizing or skincare effects (especially the prevention or improvement of dryness in healthy skin) even in low humidity environments and / or under changes in humidity. The fact that this problem, which has not been adequately addressed in conventional low humidity environments and / or under changes in humidity, can be solved by a specific combination of components from polyhydric alcohols is an unexpected effect.

[0089] The following are examples of formulations in this embodiment, but this does not narrowly limit the present technology. The compositions of each formulation example in this embodiment can have a better effect of enhancing bound water in the stratum corneum or suppressing water evaporation in the stratum corneum due to the components (A) and (B), and can be compositions for use in low humidity environments and / or under humidity changes.

[0090] Formulation Example 1: Emulsion (Oil-in-Water Type) Mass % 1. Purified water remaining amount 2. Glycerin (Ingredient (A)) 5 3. Triglycerin (Component (B)) 1 4. Ethanol 5 5.1,3-Butylene glycol 5 6. Methylgluceth-10 2 7. Dimethicone kinematic viscosity at 25°C (100 mm²) 2 / s 5 8. Cetyl ethylhexanoate 2 9. Tocopherol 0.02 10. PEG-9 Dimethicone 0.3 11. PEG-11 Methyl Ether Dimethicone 0.3 12. (Acrylates / C10-30 Alkyl Acrylate) Crosspolymer 0.2 13. Sodium hydroxide 0.06 14. Phenoxyethanol 0.3 15. Hot spring water 1 16. Serine 0.11 7. Threonine 0.01 18. Sodium hyaluronate 0.1

[0091] (Manufacturing method) A: Mix ingredients (1) to (6) uniformly at room temperature. B: Add ingredients (12) to (13) and mix and stir uniformly. Add ingredients (7) to (11) to C:B and mix and stir uniformly. Components (14) to (18) were added to D:C and mixed and stirred to obtain an emulsion (oil-in-water type). The mass ratio of component (A) and component (B) in the emulsion was 1:0.2. The emulsion (oil-in-water type) of Formulation Example 1 obtained as described above can increase the amount of bound water and suppress water evaporation under low humidity conditions and / or under changes in humidity conditions.

[0092] Formulation Example 2: Cream (Oil-in-Water Type) Mass % 1. Purified water remaining amount 2. Glycerin (Component (A)) 8 3. Triglycerin (Component (B)) 0.2 4. Ethanol 5 5.1,3-Butylene glycol 5 6. Methylgluceth-10 2 7. Macadamia nut fatty acid phytosteryl 3 8. Phytosteryl oleate 1 9. Meadowfoam oil 5 10. PEG-10 Hydrogenated Castor Oil 0.5 11. Polysorbate 80 0.1 12. (Acrylates / C10-30 Alkyl Acrylate) Crosspolymer 0.3 13. Sodium hydroxide 0.09 14. Phenoxyethanol 0.3 15. Hot spring water 1 16. Serine 0.1 17. Threonine 0.01 18. Sodium hyaluronate 0.1 19. Silica 0.5

[0093] (Manufacturing method) A: Mix ingredients (1) to (6) uniformly at room temperature. B: Add ingredients (12) to (13) and mix and stir uniformly. Add ingredients (7) to (11) to C:B and mix and stir uniformly. Components (14) to (19) were added to D:C and mixed and stirred to obtain a cream (oil-in-water type). The mass ratio of component (A) and component (B) in the cream was 1:0.025. The cream (oil-in-water type) of Formulation Example 2 obtained as described above can increase the amount of bound water and suppress moisture evaporation in low humidity environments and / or under changes in humidity environments.

[0094] Formula Example 3: Serum (by mass) 1. Purified water remaining amount 2. Glycerin (Component (A)) 8 3. Triglycerin (Component (B)) 3.2 4. Ethanol 5 5.1,3-Butylene glycol 5 6. PEG / PPG / Polybutylene Glycol-8 / 5 / 3 Glycerin 6 7. PG-3 dicaprate 8. Dimethicone (kinematic viscosity at 25°C: 100 mm² / s) 5 9. (Dimethicone / Vinyl Dimethicone) / Crosspolymer 2 10. PEG-10 Hydrogenated Castor Oil 0.5 11. Polysorbate 80 0.1 12. (Acrylates / C10-30 Alkyl Acrylate) Crosspolymer 0.2 13. Sodium hydroxide 0.06 14. Phenoxyethanol 0.3 15. Hot spring water 1 16. Serine 0.1 17. Threonine 0.01 18. Sodium hyaluronate 0.1 19. Aureobasidium pullulans culture 5

[0095] (Manufacturing method) A: Mix ingredients (1) to (6) uniformly at room temperature. B: Add ingredients (12) to (13) and mix and stir uniformly. Add ingredients (7) to (11) to C:B and mix and stir uniformly. A beauty serum was obtained by adding ingredients (14) to (19) to D:C and mixing and stirring. The mass ratio of component (A) and component (B) in the beauty serum was 1:0.4. The beauty serum obtained in this manner can increase the amount of bound water and suppress water evaporation in low humidity environments and / or under changes in humidity environments.

[0096] Formulation Example 4: Lotion (by mass) 1. Purified water (remaining) 2. Glycerin (Component (A)) 15 3. Triglycerin (Component (B)) 0.75 4.1,3-Butylene glycol 5 5. Ethanol 1 6. PEG-50 Hydrogenated Castor Oil Isostearate 0.2 7.Fragrance 0.1 8. Cyclohexane-1,4-dicarboxylic acid bisethoxydiglycol 0.1 9. Phenoxyethanol 0.3

[0097] (Manufacturing method) A: Mix ingredients (1) to (4) uniformly at room temperature. B: Mix ingredients (5) to (9) uniformly at room temperature. C:B was added to A and mixed and stirred uniformly to obtain a lotion. The mass ratio of component (A) and component (B) in the lotion was 1:0.05. The lotion obtained in this manner can increase the amount of bound water and suppress water evaporation in low humidity environments and / or under changes in humidity environments.

Claims

1. It contains component (A) glycerin and component (B) polyglycerin-3, The glycerin content is 2.5 to 25% by mass. The content of the polyglycerin-3 is 0.2 to 2% by mass. A composition used to suppress water evaporation within the stratum corneum that occurs in a low-humidity environment (where the low-humidity environment is a relative humidity of 20-40% RH at room temperature (20-30°C)), or a composition used to suppress water evaporation within the stratum corneum that occurs in the low-humidity environment by increasing the bound water within the stratum corneum.

2. The composition according to claim 1, wherein the mass ratio of glycerin and polyglycerin-3 in the composition is 1:0.01 to 0.

5.

3. The composition according to claim 1 or 2, wherein the composition is a cosmetic or a topical skin preparation.

4. It contains component (A) glycerin and component (B) polyglycerin-3, The glycerin content is 2.5 to 25% by mass. The content of the polyglycerin-3 is 0.2 to 2% by mass. A composition for moisturizing or skincare of the area where a mask is attached or removed, which is used on the face of a user wearing a mask to address localized changes in the humidity environment of the face caused by putting on and taking off a mask.

5. It contains component (A) glycerin and component (B) polyglycerin-3, The glycerin content is 2.5 to 25% by mass. The content of the polyglycerin-3 is 0.2 to 2% by mass. A composition used to suppress water evaporation within the stratum corneum caused by humidity changes due to different humidity environments, namely a low humidity environment (where the relative humidity is 20-40% RH) and a higher humidity environment (where the humidity difference between the different humidity environments is 15-25% RH), or a composition used to suppress water evaporation within the stratum corneum caused by humidity changes due to the aforementioned different humidity environments by increasing the amount of bound water within the stratum corneum.

6. Ingredient (B) contains polyglycerin-3, which is an agent that improves moisturizing function. The agent comprising a moisturizing or skincare composition containing 2.5 to 25% by mass of component (A) glycerin, which improves skin dryness problems occurring in a low humidity environment of 20 to 40% RH at room temperature (20 to 30°C), wherein polyglycerin-3 is added to the composition in an amount of 0.2 to 2% by mass.

Images