Cuticle storage promoter

Abstract

The purpose of the present invention is to provide a cosmetic or non-therapeutic method for moisturizing the stratum corneum and imparting gloss and smoothness to the skin by preparing a novel stratum corneum storage promoter and a composition for stratum corneum storage, and an external preparation for the skin, a moisturizing agent, and a gloss improving agent containing the composition, and the purpose of the present invention is to provide a cosmetic or non-therapeutic method for moisturizing the stratum corneum and imparting gloss and smoothness to the skin. The use of bis (lauramide-glutamine) lysine sodium makes it possible to promote the storage of a specific moisturizing compound in the stratum corneum, and also makes it possible to prepare a stratum corneum storage composition, an external preparation for the skin, a moisturizing agent, and a gloss improving agent, each of which contains bis (lauramide-glutamine) lysine sodium and a compound having an amide bond or an amino group. The cosmetic composition is used in a cosmetic or non-therapeutic method for moisturizing the stratum corneum and giving gloss and compactness to the skin.

Description

Technical Field

[0001] The present invention relates to a stratum corneum storage promoter, a composition for stratum corneum storage containing the stratum corneum storage promoter, and a cosmetic, beauty or non-therapeutic method using them. Background Art

[0002] Since the skin exists on the outermost layer of the living body, it is often exposed to external stimuli.

[0003] The epidermis is a very thin membrane with an average thickness of about 0.2 mm. It is located on the outermost side of the skin and serves as a barrier to prevent foreign substances from invading from the outside and body moisture from evaporating, protecting the interior. The epidermis is composed of four layers: the stratum corneum, the stratum granulosum, the stratum spinosum, and the stratum basale from the outside. The stratum corneum is located on the outermost surface of the epidermis, with an average thickness of about 0.02 mm, and is formed by the overlapping of about 10 to 20 layers of stratum corneum cells sandwiching intercellular lipids. Although the stratum corneum is a very thin membrane, it plays important roles such as a barrier function and a moisturizing function. The barrier function has two functions: preventing external stimuli such as dust and bacteria from entering the body from the skin surface and preventing excessive evaporation of body moisture to avoid body dryness. In addition, the stratum corneum is kept moist through the moisturizing function.

[0004] NMF (Natural Moisturizing Factor) is a natural moisturizer produced by the skin located in the corneocytes. NMF very easily binds to water molecules, and once bound to water, it becomes water that is very difficult to evaporate.

[0005] The components of NMF are composed of 40% free amino acids, 12% pyrrolidonecarboxylic acid (PCA), 12% lactate, 7% urea, 19% minerals, and 10% others, and more than half of it is formed by free amino acids and components derived from amino acids such as PCA. Furthermore, the components of the free amino acids therein form a composition of 30% serine, 18% glycine, 9% alanine, 7% threonine, 5% aspartic acid, and 31% others.

[0006] Therefore, in order to provide a cosmetic having a function of increasing the natural beauty of the skin to become a shiny and moist skin, a cosmetic that can keep NMF normally in the stratum corneum is required. However, NMF in the stratum corneum is easily lost through daily washing behaviors, etc., and even when administered only from the outside for the purpose of supplementation, it is difficult to store it in the surface layer.

[0007] It has been reported that there is a topical composition containing an amino acid and sodium bis(lauroylglutamyl)lysinate which has an increased percutaneous absorbability of the amino acid (Patent Document 1). Sodium bis(lauroylglutamyl)lysinate is a high-functional ingredient made from natural fatty acids and glutamic acid and lysine which are a kind of amino acids, plays a role in arranging disordered structures, supports the barrier function, and plays a role in improving water retention. However, the composition described in the above literature is a composition in which the amino acid penetrates through the stratum corneum and the skin and is absorbed into a receiving solution assumed to be deep in the skin and the whole body, and there has been no research on storage in the stratum corneum.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-33161 Summary of the Invention

[0011] Problems to be Solved by the Invention

[0012] The present invention has been made in view of the above circumstances, and an object thereof is to provide a stratum corneum storage promoter that allows a moisturizing factor such as an amino acid to penetrate into the stratum corneum and promotes storage in the stratum corneum. Further, an object of the present invention is to provide a stratum corneum storage composition that moisturizes the skin and further improves the luster of the skin by storing a target moisturizing factor in the stratum corneum.

[0013] Means for Solving the Problems

[0014] The present inventors have found that when sodium bis(lauroylglutamyl)lysinate (DLGL) is used together with a moisturizing compound having a specific structure, these compounds can be stored in the stratum corneum. Further research has revealed that these stratum corneum storage effects are based on intermolecular interactions between sodium bis(lauroylglutamyl)lysinate and the target compound. Further, the present inventors have found that by storing the moisturizing compound in the stratum corneum for a long time by sodium bis(lauroylglutamyl)lysinate (DLGL), the surface of the keratinocytes is smoothed. These are surprising effects newly obtained in the present invention.

[0015] Therefore, the present invention relates to the following inventions:

[0016] [1-1] A stratum corneum storage promoter containing sodium bis(lauroylglutamyl)lysinate.

[0017] -[1-2] Sodium bis(lauroylglutamyl)lysinate, which is used for improving skin roughness by promoting stratum corneum storage

[0018] Use.

[0019] [1-3]A method for promoting stratum corneum storage in a subject in need of increased stratum corneum storage, comprising applying sodium bis(lauroyl glutamyl) lysinate to the skin of the subject.

[0020] [1-4]Use of sodium bis(lauroyl glutamyl) lysinate for the manufacture of a stratum corneum storage promoter.

[0021] [2]According to the invention described in items 1-1 to 1-4, for promoting stratum corneum storage of a compound having an amide bond or an amino group.

[0022] [3]According to the invention described in item 2, a compound having an amide bond or an amino group is stored in the stratum corneum by the interaction of sodium bis(lauroyl glutamyl) lysinate with a compound having an amide bond or an amino group.

[0023] [4]According to the invention described in item 2 or 3, the compound having an amide bond or an amino group is a natural moisturizing factor (NMF).

[0024] [5]According to the invention described in item 4, the natural moisturizing factor (NMF) is an amino acid having an amide bond or an amino group in the side chain or a compound derived from an amino acid.

[0025] [6]According to the invention described in item 2 or 3, the compound having an amide bond or an amino group is asparagine, lysine, pyrrolidonecarboxylic acid and its salts, and uridine.

[0026] [7-1]A composition for stratum corneum storage, containing sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group, and by the interaction of the two substances, a compound having an amide bond or an amino group is stored in the stratum corneum.

[0027] [7-2]Sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group are used for improving skin roughness by promoting stratum corneum storage. Sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group, and by the interaction of the two substances, a compound having an amide bond or an amino group is stored in the stratum corneum.

[0028] [7-3]A method for promoting stratum corneum storage in a subject in need of increased stratum corneum storage, comprising applying sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group to the skin of the subject,

[0029] and by the interaction of the two substances, a compound having an amide bond or an amino group is stored in the stratum corneum.

[0030] [7-4] Use of sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group for manufacturing a composition for stratum corneum storage, by the interaction of the two substances, so as to store the compound having an amide bond or an amino group in the stratum corneum.

[0031] [8] According to the invention described in any one of Items 7-1 to 7-4, the compound having an amide bond or an amino group is a natural moisturizing factor (NMF).

[0032] [9] According to the invention described in Item 8, the natural moisturizing factor (NMF) is an amino acid having an amide bond or an amino group in the side chain or a compound derived from an amino acid.

[0033]

[10] According to the invention described in any one of Items 7-1 to 7-4, the compound having an amide bond or an amino group is asparagine, lysine, pyrrolidone carboxylic acid and its salts, and uridine.

[0034]

[11] For the composition for stratum corneum storage described in any one of Items 7-1 to 7-4 or 8, the mass ratio of sodium bis(lauroyl glutamyl) lysinate to the compound having an amide bond or an amino group is 0.01 or more.

[0035]

[12] For the composition for stratum corneum storage described in any one of Items 7-1 to 7-4 or 8, the mass ratio of sodium bis(lauroyl glutamyl) lysinate to the compound having an amide bond or an amino group is 1 or less.

[0036]

[13] A cosmetic method or non-therapeutic method for promoting the stratum corneum storage of a compound having an amide bond or an amino group, comprising the step of applying sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group to the skin.

[0037]

[14] Use of sodium bis(lauroyl glutamyl) lysinate for promoting the stratum corneum storage of a compound having an amide bond or an amino group.

[0038]

[15] A topical skin agent comprising the composition for stratum corneum storage described in any one of Items 7-1 to 12.

[0039]

[16] A moisturizer comprising the composition for stratum corneum storage described in any one of Items 7-1 to 12.

[0040]

[17] A gloss improver comprising the composition for stratum corneum storage described in any one of Items 7-1 to 12.

[0041] Effects of the invention

[0042] Sodium dilauroyl glutamyl lysinate can be used to store specific moisturizing compounds in the stratum corneum. A composition containing these two compounds is effective as a moisturizer for improving skin moisture. In addition, such storage effect makes the surface of keratinocytes smooth, and such a composition is particularly effective for use as a luster improver for enhancing the natural beauty of smooth and shiny skin. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a graph showing the stratum corneum permeability of sodium pyrrolidone carboxylate (PCA-Na) 24 hours after application. The results of non-application, PCA-Na alone (PCA), and combined application of PCA-Na and DLGL (PCA-DLGL) are shown. For the combined application of PCA-DLGL, it was confirmed that the concentration of PCA in the shallow layer where it easily flows out is high, and DLGL is effective for storing PCA-Na in the stratum corneum.

[0044] Figure 2 It is a graph showing the stratum corneum permeability of proline 24 hours after application. The results of non-application, proline alone, and combined application of proline and DLGL are shown. For the combination of L(-)-proline and DLGL, no significant difference was confirmed in the stratum corneum penetration amount after 24 hours.

[0045] Figure 3 It shows the results of measuring the surface roughness of keratinocytes after application of PCA-Na alone, DLGL alone, and PCA-Na and DLGL (PCA-DLGL). It was confirmed that by using both PCA and DLGL, the roughness of the keratinocyte surface was improved and the surface could be made smooth.

[0046] Figure 4 It is the result of measuring the moisture content of the stratum corneum using a SKICON device. For the combined application of PCA-Na and DLGL, it was confirmed that a high SKICON value was maintained even 24 hours later compared to non-application and PCA-Na alone, and the moisture content was maintained in the shallow surface layer.

[0047] Figure 5 It shows the amount of PCA in the stratum corneum after immersing the collected stratum corneum in water, PCA-Na alone (PCA), and PCA-Na and DLGL (PCA-DLGL). It was confirmed that PCA penetrated into the stratum corneum by combining PCA-Na with DLGL.

[0048] Figure 6It represents the surface roughness (Ra) of the corneocytes after the collected stratum corneum is impregnated in water, PCA-Na alone (PCA), or PCA-Na and DLGL (PCA-DLGL) and then dried. It was confirmed that the surface roughness decreased by impregnation with PCA-Na, and further decreased by using PCA-Na in combination with DLGL. Detailed implementation mode

[0049] In one aspect of the present invention, the present invention relates to a stratum corneum storage promoter containing sodium bis(laurylamido)glutamate (DLGL).

[0050] In this specification, stratum corneum storage means that moisturizing factors such as amino acids penetrate sufficiently into the stratum corneum (preferably the surface layer), and at least a part of them does not flow out and disappear from the stratum corneum even after a lapse of time after application, but is stored in the stratum corneum. Therefore, storage in the stratum corneum is completely different from the penetration and absorption of these target compounds through the stratum corneum.

[0051] The so-called stratum corneum storage promoter of the present invention refers to a compound that promotes the storage of a target compound in the stratum corneum. Regarding such a stratum corneum storage effect, it can be confirmed by measuring the concentration of the target compound in the stratum corneum using a SKICON device or the like and the amount of moisture on the surface when the stratum corneum storage promoter and the target moisturizing compound are applied together.

[0052] The stratum corneum storage promoter of the present invention can be used particularly to promote the storage of a compound having an amide bond or an amino group in the stratum corneum.

[0053] The stratum corneum storage promoter of the present invention is particularly effective for storing a moisturizing compound that easily flows out from the surface of the stratum corneum in the stratum corneum for a long time. Such an effect is based on intermolecular bonding and three-dimensional interaction between sodium bis(laurylamido)glutamate and a compound having an amide bond or an amino group. Therefore, as the target compound for stratum corneum storage, any compound can be used as long as it can interact with sodium bis(laurylamido)glutamate.

[0054] A compound having an amide bond or an amino group that can be used together with the stratum corneum storage promoter of the present invention can be a natural moisturizing factor (NMF).

[0055] Examples of the compound having an amide bond or an amino group that can be used together with the stratum corneum storage promoter of the present invention include compounds such as urea, hydroxyurea, hydroxyethyl imidazolidinone, uridine, guanine, various amino acids such as glutamine, asparagine, and lysine, pyrrolidone carboxylic acid (PCA) derived from amino acids, and glycylglycine. In particular, asparagine, lysine, and pyrrolidone carboxylic acid, which are known as NMF, are most preferred. Among them, asparagine or lysine, which are amino acids or compounds derived from amino acids having an amide bond or an amino group in the side chain in NMF, are most preferred.

[0056] One aspect of the present invention provides a composition for promoting stratum corneum storage of a compound having an amide bond or an amino group, which contains sodium bis(lauroylglutamyl)lysine and a compound having an amide bond or an amino group, and through the interaction of the two substances, the stratum corneum stores the compound having an amide bond or an amino group.

[0057] The mass ratio of sodium bis(lauroylglutamyl)lysine to the compound having an amide bond or an amino group in the composition for promoting stratum corneum storage of the present invention is, for example, 0.01 or more, preferably 0.05 or more, 0.1 or more, and more preferably 0.2 or more.

[0058] The mass ratio of sodium bis(lauroylglutamyl)lysine to the compound having an amide bond or an amino group in the composition for promoting stratum corneum storage of the present invention is, for example, 1 or less, preferably 0.8 or less, and more preferably 0.6 or less.

[0059] In addition, one aspect of the present invention provides a topical skin preparation (including pharmaceuticals, quasi-drugs, and cosmetics), a moisturizer, and a gloss improver containing the composition of the present invention. The composition of the present invention contains sodium bis(lauroylglutamyl)lysine and a compound having an amide group or an amino group, and through the interaction of the two substances, it promotes the stratum corneum storage of the target compound. Therefore, the composition for promoting stratum corneum storage of the present invention can be effectively used as a moisturizer for improving skin moisture. In addition, the interaction of such two compounds can smooth the surface of keratinocytes and impart a smooth feeling and gloss to the skin. Therefore, a composition containing sodium bis(lauroylglutamyl)lysine and a compound having an amide group or an amino group can be effectively used as a stratum corneum smoothing agent and a gloss improver.

[0060] When sodium bis(lauroylglutamyl)lysine used in the present invention is mixed in the composition for promoting stratum corneum storage, topical skin preparation, moisturizer, and gloss improver, the mixing amount of sodium bis(lauroylglutamyl)lysine in the total amount of the topical preparation (composition) is, for example, preferably 0.0001 to 10% by weight, and more preferably 0.005 to 5% by weight.

[0061] When a compound having an amide bond or an amino group, which is a compound to be stored and used together with sodium bis(lauroylglutamyl)lysinate of the present invention, is blended into a composition for stratum corneum storage, a topical skin preparation, a moisturizer, and a composition for improving luster, the blending amount of the compound having an amide bond or an amino group is preferably 0.01 to 10% by weight, more preferably 0.5 to 5% by weight, in the total amount of the topical preparation (composition).

[0062] When the composition for stratum corneum storage, the moisturizer, and the composition for improving luster of the present invention are applied as topical skin preparations, in addition to the above components, components commonly used in topical skin preparations such as cosmetics and pharmaceuticals may be appropriately blended as needed within the range that does not impair the effects of the present invention, such as antioxidants, oils, ultraviolet ray protectants, surfactants, thickeners, alcohols, powder components, colorants, aqueous components, water, various skin nutrients, etc.

[0063] Furthermore, metal ion chelating agents such as disodium ethylenediaminetetraacetate, trisodium ethylenediaminetetraacetate, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, preservatives such as methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, butyl p-hydroxybenzoate, caffeine, tannins, verapamil, tranexamic acid and its derivatives, licorice extract, glabridin, hot water extract of papaya fruit, various crude drugs, tocopheryl acetate, glycyrrhizic acid and its derivatives or salts, etc., agents, whitening agents such as vitamin C, magnesium ascorbyl phosphate, ascorbyl glucoside, arbutin, kojic acid, sugars such as glucose, fructose, mannose, sucrose, trehalose, etc. may be appropriately blended.

[0064] The topical skin preparation can be widely used in cosmetics, quasi-drugs, etc. applied to the outer skin, especially suitable for being widely used in cosmetics. As long as the dosage form can be applied to the skin, it can be any dosage form, and can be any of solution systems, solubilization systems, emulsion systems, powder dispersion systems, water-oil two-layer systems, water-oil-powder three-layer systems, ointments, lotions, gels, aerosols, etc.

[0065] The usage form is also arbitrary, and it can be used for, for example, facial cosmetics such as lotions, milks, creams, masks, makeup cosmetics such as foundations, lipsticks, eyeshadows, fragrance cosmetics, bath agents, etc.

[0066] In addition, if it is makeup cosmetics, it can be widely used in forms such as foundations, and as toiletries, it can be widely used in forms such as body washes, soaps, etc. Furthermore, if it is quasi-drugs, it can be widely used in forms such as various ointments. And the form that the composition for stratum corneum storage of the present invention can adopt is not limited to these dosage forms and forms.

[0067] When the composition for stratum corneum storage, moisturizer, and gloss improver of the present invention are used to prepare skin external preparations, pharmaceutical preparations, etc., they are beneficial for the treatment, prevention, improvement, etc. of allergic diseases such as atopic dermatitis that require moisturization, symptoms, diseases, conditions, etc. such as dry skin. As specific application examples, for example, they are suitable for use in moisturizers for human skin, gloss improvers for improving the gloss of the skin, etc. In addition, they can be applied to skin external preparations, etc. that indicate the above meanings with the physiological functions of treatment, prevention, improvement, etc. of the above symptoms, diseases, conditions, etc. as concepts.

[0068] One aspect of the present invention relates to a cosmetic or non-therapeutic method for promoting the storage of a compound having an amide bond or an amino group in the stratum corneum, which includes a step of applying sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group to the skin.

[0069] The composition for stratum corneum storage, skin external preparation, moisturizer, and gloss improver disclosed in this specification can be used in cosmetic or non-therapeutic methods for moisturizing human skin (keeping the skin moist), improving gloss (giving a smooth feeling and gloss), etc. In the cosmetic or non-therapeutic method related to the present invention, the above skin external preparation composition is applied to the part where the desired effect is to be obtained, such as the face, neck, hands, arms, feet, etc. The application can be carried out in any manner such as application by hand, application tool, etc. The number of applications, frequency, amount, etc. are appropriately set according to the desired effect, etc. In addition, the cosmetic or non-therapeutic method related to the present invention does not include so-called medical acts.

[0070] Furthermore, one aspect of the present invention relates to the use of sodium bis(lauroyl glutamyl) lysinate for promoting the storage of a compound having an amide bond or an amino group in the stratum corneum. The data disclosed in this specification confirm that sodium bis(lauroyl glutamyl) lysinate promotes the storage of a compound having an amide bond or an amino group in the stratum corneum. Therefore, sodium bis(lauroyl glutamyl) lysinate can be used to promote the storage of a compound having an amide bond or an amino group in the stratum corneum.

[0071] All the documents mentioned in this specification are incorporated into this specification by reference in their entirety.

[0072] The examples of the present invention described below are for illustrative purposes only and do not limit the technical scope of the present invention. The technical scope of the present invention is limited only by the description in the claims. Changes to the present invention can be made on the condition that the gist of the present invention is not exceeded. For example, addition, deletion, and replacement of the constituent elements of the present invention can be carried out.

[0073] Example 1

[0074] Example 1: Cutaneous Permeability of PCA-Na

[0075] Sodium bis(lauroylglutamyl)lysinate (DLGL, raw material name: Perisea L-30, manufactured by Asahi Kasei Finechem Co., Ltd., containing 29% by weight of DLGL) and sodium pyrrolidone carboxylate (PCA-Na, raw material name: AJIDEW N-50, manufactured by Ajinomoto HealthSupplies Co., Ltd., containing 50% by weight of PCA-Na) were used to prepare samples of uncoated, PCA-Na alone, and PCA-Na and DLGL (PCA-DLGL) as described below.

[0076] Table 1

[0077]

[0078] Coating amount: 2 μL / cm 2

[0079] Reviewers: 5 Japanese men (age: 28.8 ± 1.0)

[0080] Each sample was applied to the inner side of the forearm. After 24 hours, it was washed twice with soap, and the stratum corneum was stripped 10 times using D-squame (registered trademark) stripping disks (Clinical&Derm). Each stripped disk was immersed in 0.5 mL of a 30% aqueous acetonitrile solution, and PCA-Na was extracted by ultrasonic treatment for 15 minutes. PCA-Na was quantified by LCMS. The total amounts of the 1st - 5th layers, 6th - 10th layers, and all layers from the surface were measured.

[0081] The results are shown in Figure 1 . It was confirmed that by using both PCA and DLGL, the concentration of PCA in the shallow layer where it is particularly likely to flow out is high, and DLGL is effective for storing PCA-Na in the stratum corneum.

[0082] Example 2: Cutaneous Permeability of Proline

[0083] In Example 1, PCA-Na was replaced with L(-)-proline (FUJIFILM Wako Pure Chemical Corporation), and the same evaluation was carried out. The results are shown in Figure 2 . For the combination of L(-)-proline and DLGL, no significant difference was confirmed in the amount of penetration into the stratum corneum after 24 hours.

[0084] Example 3: Effects on Keratinocytes

[0085] The above samples were used at 5 μL / cm 2The capacity was applied to the inner forearm of 7 Japanese male reviewers aged in their 20s to 40s. After 1 hour, the stratum corneum was peeled off with tape, transferred to a D-squame (registered trademark) stripping plate (Clinical&Derm), and the keratinocytes were observed with a laser microscope (KEYENCE). The surface roughness (Ra) of the keratinocytes after applying each sample was measured. ΔRa was calculated by subtracting the surface roughness (Ra) after applying water from the surface roughness (Ra) after applying each sample, and the results are shown in Figure 3 It was confirmed that by using both PCA and DLGL, the roughness of the keratinocyte surface was improved and the surface could be smoothed.

[0086] Example 4: Moisturizing Effects of PCA-Na and DLGL

[0087] The water content of the stratum corneum was measured using SKICON EX-200 (a skin surface stratum corneum water content measuring device, manufactured by Yayoisha) under the following conditions.

[0088] <SKICON measurement>

[0089] Application amount: 2 μL / cm 2

[0090] Reviewers: 5 Japanese (age: 30.2 ± 2.6 years)

[0091] Analysis was performed on 4 reviewers excluding 1 reviewer with redness.

[0092] Samples of no application, PCA-Na applied alone, and PCA-Na and DLGL applied (PCA-DLGL) were washed once with soap after 1, 6, and 24 hours, and then measured.

[0093] The difference in the SKICON value relative to that before application is shown in Figure 4 For the application of PCA-Na and DLGL, it was confirmed that a high SKICON value was maintained even after 24 hours, and the water content was maintained in the shallow surface layer.

[0094] Example 5: Interaction between Each Compound and DLGL

[0095] The presence or absence of the interaction between the compound to be stored and DLGL was evaluated by measuring the change in the IR spectrum (NICOLET iS50 ATR, Thermo). The number of scans was set to 32 times. The evaluation was determined by the presence or absence of the shift of the absorption spectrum of a specific bond of the compound when the amount of DLGL relative to PCA was increased. Since the peak shift of the IR spectrum indicates the change in the environment around each functional group, the interaction between the two compounds could be confirmed. The results of the interaction between PCA-Na and DLGL are shown in Table 2.

[0096] Table 2

[0097]

[0098] When adding at least 0.23 or more of DLGL relative to PCA1 by weight ratio, the peak shifted, and it was confirmed that DLGL interacted with PCA-Na from a low concentration.

[0099] The results of the interaction between L-asparagine monohydrate, uridine, L(+)-lysine hydrochloride and DLGL are shown in Table 3.

[0100] Table 3

[0101] Asparagine Alone Uridine Alone Lysine Alone <![CDATA[Derived from NH2(cm -1 )]]> <![CDATA[Derived from C=O(cm -1 )]]> <![CDATA[Derived from CN(cm -1 )]]> Agent Alone 1635.0 1662.34 1404.39 Ratio of Agent to DLGL: 1 1622.8 1683.95 1401.8 DLGL Alone - - -

[0102] In Table 3, the IR peaks of L-asparagine monohydrate (FUJIFILM Wako Pure Chemical Industries, Ltd.), uridine (FUJIFILM Wako Pure Chemical Industries, Ltd.) and L-lysine hydrochloride (FUJIFILM Wako Pure Chemical Industries, Ltd.), and samples with DLGL added at a weight ratio of 1 in each compound were measured. It was confirmed that by adding DLGL, the peaks near the amide bonds of L-asparagine monohydrate and uridine and the amino group of L(+)-lysine hydrochloride shifted, and DLGL interacted with the amide bonds and amino groups of each compound.

[0103] Example 6: Water Retention Capacity of PCA-Na and DLGL

[0104] The ratio of frozen water and the ratio of non-frozen water were calculated by measuring the heat of fusion under the following conditions using differential scanning calorimetry (DSC, TA Q-2000, TA Instruments), and the amount of bound water of PCA-Na and DLGL was measured.

[0105] Step size: 1 °C / min

[0106] Temperature:

[0107] · Sample: Solid component 11%

[0108] Calculation method

[0109] Ratio of frozen water = Heat of fusion of 1 g of water in each sample / Heat of fusion of 1 g of pure water

[0110] Ratio of non-frozen water = 1 - Ratio of frozen water

[0111] The non-frozen water was converted to non-frozen bound water.

[0112] The results are shown in Table 4.

[0113] Table 4

[0114] Ratio of DLGL to PCA Frozen Water Ratio (%) Unfrozen Bound Water Content (%) 0 0.70 0.30 0.3 0.68 0.32 0.5 0.69 0.31 1.0 0.72 0.28 2.0 0.77 0.23 4.0 0.77 0.23

[0115] It was confirmed that the amount of bound water did not change up to a weight ratio of 1, but when the mass ratio was 2 or more, the proportion of non-freezable bound water decreased.

[0116] Example 7: In the separated stratum corneum Permeability of PCA-Na

[0117] Sodium bis(lauramidoglutamyl)lysinate (DLGL, raw material name: Perisea L-30 manufactured by Asahi Kasei Finechem Co., Ltd., containing 29% by weight of DLGL) and sodium pyrrolidone carboxylate (PCA-Na, raw material name: AJIDEW N-50 manufactured by Ajinomoto Helsi Supply Co., Ltd.: containing 50% by weight of PCA-Na) were used to prepare samples of PCA-Na alone (PCA) and PCA-Na and DLGL (PCA-DLGL) as described below. As a control, water was used.

[0118] Table 5

[0119] Water PCA PCADLGL Active Ingredient Concentration PCA-Na 0.22 0.22 0.11 DLGL 0.1 0.029

[0120] The stratum corneum taken from the back skin of a 39-year-old male (Caucasian) was punched out into a circle with a diameter of 1 cm, and Aron Alpha A "Sankyo" (Toagosei Co., Ltd.) was applied to the epidermal side and pasted on a Teflon sheet. The stratum corneum specimen thus obtained was immersed in the sample prepared above for 5 minutes (n = 4). After immersion, the stratum corneum specimen was taken out and left to stand indoors overnight. It was washed 3 times in MilliQ water and left to stand overnight. The stratum corneum specimen was added to 1 mL of a 30% aqueous acetonitrile solution and extracted by ultrasonic wave for 20 minutes, and PCA-Na was quantified by LCMS. The results are shown in Figure 5 . For water, it was the lower limit of quantification (BLQ). On the other hand, by using both PCA and DLGL, the penetration of PCA into the stratum corneum was promoted.

[0121] Example 8: In the separated stratum corneum Effects of PCA-Na on Keratinocytes

[0122] Sodium bis(lauramidoglutamyl)lysinate (DLGL, raw material name: Perisea L-30 manufactured by Asahi Kasei Finechem Co., Ltd., containing 29% by weight of DLGL) and sodium pyrrolidone carboxylate (PCA-Na, raw material name: AJIDEW N-50 manufactured by Ajinomoto Helsi Supply Co., Ltd.: containing 50% by weight of PCA-Na) were used to prepare samples of PCA-Na alone (PCA) and PCA-Na and DLGL (PCA-DLGL) as described below. As a control, water was used.

[0123] Table 6

[0124] Water PCA PCADLGL Active Ingredient Concentration PCA-Na 0.22 0.22 0.11 DLGL 0.1 0.029

[0125] Tape was pasted on the inner forearm of 4 male subjects aged 20 to 40 years old, and the stratum corneum was taken. The adhesive layer of the tape was pasted on the adhesive layer of a D-squame (registered trademark) standard sampling disk (standard sampling disks) (Clinical&Derm), and the stratum corneum was transferred. The disk was immersed in various sample aqueous solutions for 5 seconds and dried overnight. The keratinocytes were observed with a laser microscope (KEYENCE), and the surface roughness (Ra) of the keratinocytes after immersion in various samples was measured. The results are shown in Figure 6 . It was confirmed that by using both PCA and DLGL, the roughness of the keratinocyte surface was improved and the surface could be smoothed.

[0126] From Figures 1 - 6 The results also clearly confirmed that by using DLGL as a stratum corneum storage promoter, the concentration of PCA-Na in the stratum corneum could be maintained even after a long time after application, and DLGL was effective for storing PCA-Na in the stratum corneum. It was confirmed that by using both PCA-Na and DLGL, the roughness of the keratinocyte surface was improved and the surface could be smoothed. It was further confirmed that such a stratum corneum storage effect was effective for increasing the amount of moisture in the shallow surface layer of the stratum corneum close to the skin surface. It was confirmed that the long-term stratum corneum storage after application was based on the intermolecular interaction with the target compound. Therefore, it was suggested that the stratum corneum storage composition containing the stratum corneum storage promoter of the present invention was effective for use as a moisturizer and a gloss improver for imparting moisture to the skin.

Claims

1. A stratum corneum storage promoter, comprising sodium bis(lauroyl glutamyl) lysinate.

2. The stratum corneum storage promoter according to claim 1, which is used to promote the stratum corneum storage of a compound having an amide bond or an amino group.

3. The stratum corneum storage promoter according to claim 2, wherein the sodium bis(lauroyl glutamyl) lysinate interacts with the compound having an amide bond or an amino group to store the compound having an amide bond or an amino group in the stratum corneum.

4. The stratum corneum storage promoter according to claim 2 or 3, wherein the compound having an amide bond or an amino group is natural moisturizing factor NMF.

5. The stratum corneum storage promoter according to claim 4, wherein the natural moisturizing factor NMF is an amino acid having an amide bond or an amino group in the side chain or a compound derived from an amino acid.

6. The stratum corneum storage promoter according to claim 2 or 3, wherein the compound having an amide bond or an amino group is asparagine, lysine, pyrrolidone carboxylic acid and its salts, and uridine.

7. A composition for stratum corneum storage, containing sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group, and the two substances interact to store the compound having an amide bond or an amino group in the stratum corneum.

8. The composition for stratum corneum storage according to claim 7, wherein the compound having an amide bond or an amino group is natural moisturizing factor NMF.

9. The composition for stratum corneum storage according to claim 8, wherein the natural moisturizing factor NMF is an amino acid having an amide bond or an amino group in the side chain or a compound derived from an amino acid.

10. The composition for stratum corneum storage according to claim 7, wherein the compound having an amide bond or an amino group is asparagine, lysine, pyrrolidone carboxylic acid and its salts, and uridine.

11. The composition for stratum corneum storage according to claim 7 or 8, wherein the mass ratio of sodium bis(lauroyl glutamyl) lysinate to the compound having an amide bond or an amino group is 0.01 or more.

12. The composition for stratum corneum storage according to claim 7 or 8, wherein the mass ratio of sodium bis(lauroyl glutamyl) lysinate to the compound having an amide bond or an amino group is 1 or less.

13. A cosmetic method or non-therapeutic method for promoting the stratum corneum storage of a compound having an amide bond or an amino group, comprising the step of applying sodium bis(lauroyl glutamyl) lysinate and a compound having an amide bond or an amino group to the skin.

14. Use of sodium bis(lauroyl glutamyl) lysinate for promoting the stratum corneum storage of a compound having an amide bond or an amino group.

15. A topical skin agent, comprising the composition for stratum corneum storage according to any one of claims 7 to 12.

16. A moisturizer, comprising the composition for stratum corneum storage according to any one of claims 7 to 12.

17. A gloss improver, comprising the composition for stratum corneum storage according to any one of claims 7 to 12.

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