Ceramide proliferation promoter

Abstract

The present invention pertains to a ceramide growth promoting agent that contains a ceramide illustrated by general formula (1). Through the use of a specific ceramide, the present invention provides a ceramide growth promoting agent that not only supplements ceramide from the outside, but also causes the growth of diverse ceramides. (In the formula, R1 represents a C13-21 monovalent hydrocarbon group that may have a hydroxyl group or a double bond, and Z represents a C14-24 acyl group that may have hydrogen atoms, an acetyl group, or a hydroxyl group.)

Description

[Technical Field]

[0001] The present invention relates to a ceramide proliferation promoter, which is characterized by promoting the conversion to and proliferation of various ceramide species by applying a preparation containing dihydroceramides. [Background technology]

[0002] The skin plays a very important role as a barrier membrane that protects against biological, chemical, and physical insults from the outside world, such as microorganisms, chemicals, and ultraviolet rays, while also preventing the loss of essential biological components such as moisture. The barrier membrane is the stratum corneum, located in the outermost layer of the epidermis and approximately 20 μm thick. Intercellular lipids hold the brick-like stacks of keratinocytes together like mortar, forming a strong barrier membrane. Ceramides, a key component of intercellular lipids in this keratinocyte, are known to build a lipid barrier and play an important role in keeping the skin soft and moisturized (Non-Patent Documents 1 and 2).

[0003] In recent years, it has become clear that the content of ceramides in the intercellular lipids of keratinocytes in the skin of patients with rough skin, dry skin, or atopic dermatitis is significantly reduced compared to the skin of healthy people. Therefore, attempts have been made to improve the skin's barrier function and moisturizing function by applying ceramides to rough or damaged skin to replenish it.

[0004] On the other hand, attempts have been made to improve the skin barrier function and moisturizing function by promoting the ceramide production mechanism using extracts of eucalyptus, cattail, soapwort, clove, etc. as active ingredients (Patent Document 1).

[0005] Abbreviations for ceramides are shown in Figure 1. Ceramides are classified into 12 types based on the combination of a sphingosine base and a long-chain fatty acid that constitutes the amide side chain, and may be represented by abbreviations in this specification. Ceramide EOS (Figure 1: CER[EOS]) is sometimes referred to as ceramide 1, ceramide NS (Figure 1: CER[NS]) is sometimes referred to as ceramide 2, and ceramide NDS (Figure 1: CER[NDS]) is sometimes referred to as dihydroceramide 2.

[0006] Here, as prior art, there is a report on the effect of promoting ceramide production by applying a mixture of ceramide 1, ceramide 2, and ceramide 3 (Non-Patent Document 3), and a delivery system using a formulation consisting of water, fatty acids, cholesterol, and ceramide / phospholipids has been proposed (Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 10-152428 [Patent Document 2] Japan Special Publication No. 2005-522463 [Non-patent literature]

[0008] [Non-Patent Document 1] Downing DT, et al., J.Lipid.Res.,24, 759 (1983) [Non-patent document 2] Downing DT, et al., J.Invest.Dermat.,84, 410 (1985) [Non-patent document 3] M. Komorizono., et al., Aesthetic dermatology, 26(2), 269 (2016) Summary of the Invention [Problem to be solved by the invention]

[0009] However, the method of externally supplementing ceramides described in Patent Document 1 has various issues, such as the fact that the types of ceramides that can be used are limited, and attempts to promote ceramide production from within require the production promoter to reach deep into the epidermis where the conversion enzymes that act on it are present (for example, in the case of serine palmitoyltransferase, the nucleated basal layer, spinous layer, and granular layer), and furthermore, there are individual differences in production ability, and therefore the development of a more effective formulation has been desired.

[0010] Furthermore, the technology described in Non-Patent Document 3 requires a mixture of expensive ceramide 1, ceramide 2, and ceramide 3. Furthermore, the technology described in Patent Document 2 requires fatty acids as system components, and specific examples of ceramides are the same as those in Non-Patent Document 3, including expensive ceramide 1, ceramide 3, ceramide 6II, and phytosphingosine, a precursor of ceramide NP. As such, the effects of using ceramides alone, much less dihydroceramide 2 (ceramide NDS) alone, and the efficacy of a system that does not require fatty acids were completely unknown.

[0011] The present invention was made under these circumstances, and aims to provide a formulation and technology that not only supplements ceramides from the outside but also enables the proliferation of various ceramide species in topical skin preparations. Note that, in this disclosure, "proliferation of ceramides" means promoting the biosynthesis and / or synthesis of ceramides in the stratum corneum of the epidermis. [Means for solving the problem]

[0012] In view of the above circumstances, the present inventors have conducted extensive research and have found that application of specific ceramides not only supplements ceramides from the outside but also enables the proliferation of various ceramide species, thereby completing the present invention. That is, the present invention includes the following: [1] A ceramide proliferation promoter containing a ceramide represented by the following general formula (1):

[0013] [ka]

[0014] (In the formula, R1 represents a hydroxyl group or a monovalent hydrocarbon group having 13 to 21 carbon atoms which may have a double bond, and Z represents a hydrogen atom, an acetyl group, or an acyl group having 14 to 24 carbon atoms which may have a hydroxyl group.) [2] The ceramide proliferation promoter according to [1], wherein the ceramide represented by the general formula (1) is a ceramide represented by the following general formula (2):

[0015] [ka]

[0016] (In the formula, R1 represents a hydroxyl group or a monovalent hydrocarbon group having 13 to 21 carbon atoms which may have a carbon-carbon double bond, and Z represents a hydrogen atom, an acetyl group, or an acyl group having 14 to 24 carbon atoms which may have a hydroxyl group.) [3] The ceramide proliferation promoter according to [1] or [2], wherein R1 in the general formula (1) or (2) is a monovalent saturated hydrocarbon group having 13 to 21 carbon atoms. [4] The ceramide proliferation promoter according to any one of [1] to [3], further comprising at least one of cholesterol, phytosterol, polyglycerol fatty acid ester, and polyhydric alcohol. [5] R1 in the general formula (1) or (2) is a monovalent saturated hydrocarbon group having 13 to 21 carbon atoms, The ceramide proliferation promoter according to any one of [1] to [4], further comprising water and one or more of cholesterol, decaglycerol monostearate, butylene glycol, and glycerin. [6] The ceramide proliferation promoter according to any one of [1] to [5], wherein the ceramide to be proliferated is a ceramide represented by the following general formula (3):

[0017] [ka]

[0018] (In the formula, R2 represents a monovalent hydrocarbon group of 13 to 21 carbon atoms which may have a carbon-carbon double bond and / or a hydroxyl group, R3 represents a divalent saturated hydrocarbon group of 13 to 31 carbon atoms which may have a hydroxyl group, Y represents a hydrogen atom or an O-acyl bond via a hydroxyl group, and R4 is absent when Y is a hydrogen atom, or represents a monovalent hydrocarbon group of 15 to 25 carbon atoms which may have a carbon-carbon double bond when Y is an O-acyl bond via a hydroxyl group.) [7] The ceramide proliferation promoter according to any one of [1] to [5], wherein the ceramide to be proliferated is a ceramide represented by the following general formula (4):

[0019] [ka]

[0020] (In the formula, R5 represents a monovalent hydrocarbon group having 13 to 21 carbon atoms and a carbon-carbon double bond, and X represents an acyl group having 14 to 24 carbon atoms.) [8] The ceramide proliferation promoter according to any one of [1] to [7], wherein the diameter of the dispersed particles is 0.45 μm or less. [9] The ceramide proliferation promoter according to any one of [1] to [8], which is substantially free of fatty acids and / or phospholipids and is composed only of nonionic components.

[10] A skin cosmetic, a skin protectant, a hair composition, a lip care preparation, a skin cleanser, or a bath additive, which contains the ceramide proliferation promoter according to any one of [1] to [9].

[11] A method for increasing and / or supplementing various ceramide species in the stratum corneum of the skin by applying the ceramide proliferation promoter according to any one of [1] to [9]. [Effects of the Invention]

[0021] As described above, the ceramide proliferation promoter of the present invention, which contains ceramides with specific structures, promotes the proliferation of various ceramides, thereby enabling the production of ceramides in an appropriate balance. Furthermore, the formulation is stable, safe, and easy to use, and can be diluted as desired into a wide range of skin and hair (scalp) preparations, significantly expanding its use as a raw material for cosmetics and pharmaceuticals. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 shows the abbreviations for ceramides. [Figure 2] FIG. 2 shows the culture and formulation addition tests. [Figure 3] FIG. 3 shows the results of quantitative determination of ceramide EOSs. [Figure 4] FIG. 4 shows the results of quantifying ceramide NSs. [Figure 5] FIG. 5 shows the results of quantifying ceramide NDSs. DETAILED DESCRIPTION OF THE INVENTION

[0023] The ceramides used in the present invention are represented by the following formula (1):

[0024] [ka]

[0025] (In the formula, R1 represents a monovalent hydrocarbon group having 13 to 21 carbon atoms which may have a hydroxyl group or a double bond, and Z represents a hydrogen atom, an acetyl group, or an acyl group having 14 to 24 carbon atoms which may have a hydroxyl group.) It is a known compound represented by the formula:

[0026] The compound of general formula (1) can be obtained from mammalian extracts such as human or pig skin, bovine brain, or red blood cells, or from plant extracts such as soybean or wheat, but synthetic products obtained by known production methods are preferably used in terms of purity.

[0027] Specific compounds represented by general formula (1) include 2-tetradecanoylaminooctadecane-1,3-diol, 2-hexadecanoylaminooctadecane-1,3-diol, 2-octadecanoylaminooctadecane-1,3-diol, 2-eicosanoylaminooctadecane-1,3-diol, 2-oleoylaminooctadecane-1,3-diol, 2-linoleoylaminooctadecane-1,3-diol, 2-(2-hydroxyhexadecanoyl)aminooctadecane-1,3-diol, 2-(3-hydroxyhexadecanoyl)aminooctadecane-1,3-diol, 2-tetradecanoylaminooctadecane-1,3-diol, 2-tetradecanoylaminooctadecane-1,3-diol, 2-hexadecano ... Examples thereof include ladecanoylaminohexadecane-1,3-diol, 2-hexadecanoylaminohexadecane-1,3-diol, 2-octadecanoylaminohexadecane-1,3-diol, 2-eicosanoylaminohexadecane-1,3-diol, 2-oleoylaminohexadecane-1,3-diol, 2-linoleoylaminohexadecane-1,3-diol, 2-(2-hydroxyhexadecanoyl)aminohexadecane-1,3-diol, and 2-octadecanoylaminooctadecane-1,3,4-triol, and these can be used alone or in combination of two or more.

[0028] Furthermore, the ceramides used in the present invention are particularly those represented by the following general formula (2):

[0029] [ka]

[0030] (In the formula, R1 represents a hydroxyl group or a monovalent hydrocarbon group having 13 to 21 carbon atoms which may have a carbon-carbon double bond, and Z represents a hydrogen atom, an acetyl group, or an acyl group having 14 to 24 carbon atoms which may have a hydroxyl group.) Optically active natural ceramides represented by the following formula are preferably used.

[0031] Specific compounds represented by general formula (2) include (2S,3R)-2-tetradecanoylaminooctadecane-1,3-diol, (2S,3R)-2-hexadecanoylaminooctadecane-1,3-diol, (2S,3R)-2-octadecanoylaminooctadecane-1,3-diol, (2S,3R)-2-nonadecanoylaminooctadecane-1,3-diol, (2S,3R)-2-eicosanoylaminooctadecane-1,3-diol, (2S,3R)-2-oleoylaminooctadecane-1,3-diol, (2S,3R)-2-linoleoylaminooctadecane-1,3-diol, (2S,3R)-2-(2-hydroxyhexadecanoyl)aminooctadecane-1,3-diol, (2S,3R)-2-(3-hydroxyhexadecanoyl)aminooctadecane-1,3-diol, (2S,3 R)-2-tetradecanoylaminohexadecane-1,3-diol, (2S,3R)-2-hexadecanoylaminohexadecane-1,3-diol, (2S,3R)-2-octadecanoylaminohexadecane-1,3-diol, (2S,3R)-2-nonadecanoylaminohexadecane-1,3-diol, (2S,3R)-2-eicosanoylaminohexadecane-1,3-diol, (2S,3R)- Examples include 2-oleoylaminohexadecane-1,3-diol, (2S,3R)-2-linoleoylaminohexadecane-1,3-diol, (2S,3R)-2-(2-hydroxyhexadecanoyl)aminohexadecane-1,3-diol, and (2S,3S,4R)-2-octadecanoylaminooctadecane-1,3,4-triol, and these can be used alone or in combination of two or more.

[0032] It is particularly preferable that R1 in general formula (1) or (2) is a monovalent saturated hydrocarbon group having 13 to 21 carbon atoms. Compounds in general formula (1) or (2) in which R1 is a monovalent saturated hydrocarbon group having 13 to 21 carbon atoms are classified as dihydroceramides (ceramide NDS) (CER(NDS) in FIG. 1).

[0033] The total content of these ceramides in the ceramide proliferation promoter of the present invention is preferably 0.001 to 10% by mass, and more preferably 0.01 to 5% by mass, based on the total amount of the ceramide proliferation promoter.

[0034] The ceramide proliferation promoter of the present invention preferably further contains, in addition to the above-mentioned ceramides, one or more of sterols such as cholesterol or phytosterol, polyglycerol fatty acid esters, and polyhydric alcohols. By using these components in combination, the components of the ceramide proliferation promoter can be suitably adjusted.

[0035] More specifically, cholesterol, campestrol, stigmasterol, and sitosterol are preferably used as sterols, and cholesterol, which is a natural component of the stratum corneum, is particularly preferred. When sterols are used in combination, the content of the sterols is preferably 20 to 150% by mass relative to the ceramides.

[0036] The polyglycerin acid fatty acid esters preferably have a hydrophilic-lipophilic balance (HLB) of 10 or higher. The polyglycerin group of the polyglycerin fatty acid ester preferably has a degree of polymerization of 5 or higher, particularly preferably 8 to 12. Furthermore, the fatty acid residue is preferably a C12-24 residue, such as lauric acid residue, myristic acid residue, palmitic acid residue, stearic acid residue, behenic acid residue, isostearic acid residue, or oleic acid residue. Furthermore, the number of fatty acid residues is preferably greater than the number of free hydroxyl groups. Preferably, there are 5 to 20 free hydroxyl groups per fatty acid residue. Particularly preferred examples include decaglycerin monomyristate (HLB 14), pentaglycerin monostearate (HLB 11), decaglycerin monostearate (HLB 13.5), pentaglycerin monoisostearate (HLB 11), and decaglycerin monooleate (HLB 13). These components may be contained alone or in combination of two or more.

[0037] These components act as hydrophilic surfactants. The fatty acid esters of polyglycerin easily form a liquid crystal structure together with the poorly water-soluble component and the alcohol, and when the liquid crystal structure is formed in at least a part of the matrix, the ceramide component is present on the skin as a matrix that is easily absorbed percutaneously.

[0038] Preferred examples of treatment methods that facilitate the formation of liquid crystals include: 1) heating matrix components containing poorly soluble ceramides and alcohols to dissolve them together; 2) diluting the matrix with a non-aqueous component other than the matrix components, which contains a surfactant, a fatty acid ester of polyglycerin, and a polyhydric alcohol, that has been previously heated and dissolved together; and 3) adding a pre-heated aqueous component to the diluted solution, followed by cooling.

[0039] The amount of the fatty acid ester of polyglycerin is preferably 2 to 20 times by mass the total amount of ceramides.

[0040] Examples of polyhydric alcohols include 1,3-butanediol, dipropylene glycol, glycerin, diglycerin, isoprene glycol, 1,2-pentanediol, and 1,2-hexylene glycol, and these can be used alone or in combination of two or more. 1,3-butanediol and glycerin are particularly preferred.

[0041] There is no particular limit to the content of polyhydric alcohols, but the use of 10 to 50 times the mass of ceramides is preferred as a preparation for stably dispersing the above-mentioned ceramides in water.

[0042] The ceramide proliferation promoter of the present invention can contain optional ingredients that are commonly used in external preparations for skin and hair, separated into either a non-aqueous component phase or an aqueous phase, within the range that does not impair the effects of the present invention.Such optional ingredients include, for example, hydrocarbons such as squalane, liquid paraffin, light liquid isoparaffin, heavy liquid isoparaffin, microcrystalline wax, and solid paraffin, silicones such as dimethicone, femethicone, cyclomethicone, amodimethicone, and polyether-modified silicone, jojoba oil, carnauba wax, Japan wax, beeswax, pearl wax, octyldodecyl oleate, isopropyl myristate, dineopentyl glycol diisostearate, and diisostearate malate. Esters such as acrylates, fatty acids such as stearic acid, lauric acid, myristic acid, palmitic acid, isostearic acid, isopalmitic acid, behenic acid, and oleic acid, castor oil, coconut oil, hydrogenated coconut oil, camellia oil, wheat germ oil, isostearic acid triglyceride, isooctanoic acid triglyceride, and triglycerides such as olive oil, 1,3-butanediol, glycerin, diglycerin, dipropylene glycol, polyethylene glycol, 1,2-pentanediol, 1,2-hexylene glycol Preferred examples of the active ingredient include polyhydric alcohols such as cellulose and isoprene glycol, organic powders such as crystalline cellulose, crosslinked methylpolysiloxane, polyethylene powder, and acrylic resin powder, powders which may be surface-treated such as talc, mica, sericite, magnesium carbonate, calcium carbonate, titanium dioxide, iron oxide, Prussian blue, ultramarine, titanium mica, titanium sericite, and silica, acrylate-methacrylate alkyl copolymers and / or salts thereof, carboxyvinyl polymers and / or salts thereof, thickeners such as xanthan gum and hydroxypropyl cellulose, active ingredients such as vitamins such as retinol, retinoic acid, tocopherol, riboflavin, pyridoxine, ascorbic acid, and ascorbic acid phosphate salts, and steroids such as estradiol, ethinylestradiol, and estriol, preservatives such as phenoxyethanol, parabens, hibitene gluconate, and benzalkonium chloride, and ultraviolet absorbers such as dimethylaminobenzoates, cinnamates, and benzophenones.These may be used alone or in combination of two or more.

[0043] However, fatty acids such as stearic acid, lauric acid, myristic acid, palmitic acid, isostearic acid, isopalmitic acid, behenic acid, and oleic acid require pH adjustment with an alkaline agent, and neutralization with alkaline salts such as sodium and potassium can cause skin irritation. Therefore, unless intentionally used as active ingredients in skin and hair cleansers, they are preferably not used, and preferably are substantially free of them. Furthermore, phospholipids such as lecithin are preferably substantially free of them, in view of the risk that their surfactant activity may affect the essence of the present invention. Furthermore, in view of the risk of affecting the pH of the product, the ceramide proliferation promoter of the present invention is preferably composed solely of nonionic components. Nonionic components primarily refer to nonionic surfactants, such as fatty acid esters of polyglycerin. The ceramide proliferation promoter of the present invention can be used in any of a variety of skin and hair topical pharmaceutical preparations. Examples of preparations containing the ceramide proliferation promoter of the present invention include skin cosmetics, skin protectants, hair compositions, lip care preparations, skin cleansers, and bath additives.

[0044] The ceramide proliferation promoter of the present invention preferably has a dispersed particle diameter of 0.45 μm or less. Ceramides having a particle size in this range are preferably able to pass through many treatment membranes in formulation development. In addition, to achieve the particle size of ceramides in the above range, it is preferable that the ceramide proliferation promoter contains, for example, a polyglycerol fatty acid ester.

[0045] It has been known that applying a ceramide-containing preparation as an external preparation improves the barrier function and moisturizing function of the skin, but the ceramide proliferation promoter of the present invention contains dihydroceramides, particularly those having a dihydrosphingosine skeleton, and thus has the effect of converting them into various ceramide species and / or promoting the proliferation effect of various ceramide species. Such findings were completely unknown.

[0046] According to the ceramide proliferation promoter of the present invention, ceramides represented by the following general formula (3) (ceramide EOS) and ceramides represented by the following general formula (4) (ceramide NS) are preferably proliferated.

[0047] [ka]

[0048] (In the formula, R2 represents a monovalent hydrocarbon group of 13 to 21 carbon atoms which may have a carbon-carbon double bond and / or a hydroxyl group, R3 represents a divalent saturated hydrocarbon group of 13 to 31 carbon atoms which may have a hydroxyl group, Y represents a hydrogen atom or an O-acyl bond via a hydroxyl group, and R4 is absent when Y is a hydrogen atom, or represents a monovalent hydrocarbon group of 15 to 25 carbon atoms which may have a carbon-carbon double bond when Y is an O-acyl bond via a hydroxyl group.)

[0049] [ka]

[0050] (In the formula, R5 represents a monovalent hydrocarbon group having 13 to 21 carbon atoms and a carbon-carbon double bond, and X represents an acyl group having 14 to 24 carbon atoms.) [Example]

[0051] Next, the present invention will be explained in more detail with reference to Examples and Test Examples, but the present invention is not limited to these Examples.

[0052] In this example, the ceramide NDS used was manufactured by Takasago International Corporation, and the other ceramides used were manufactured by Avanti Polar Lipids.

[0053] Example 1 According to the recipe shown below, a ceramide dispersion preparation (ceramide composition) containing (2S,3R)-2-octadecanoylaminooctadecane-1,3-diol (dihydroceramide 2 = ceramide NDS) with an optical purity and chemical purity of 95% or more was produced. After the lipid component consisting of component (a) was uniformly dissolved at approximately 120°C, component (b) was then added at the same temperature. After the component was dissolved to a transparent state, component (c), which had been preheated to 80-90°C, was gradually added dropwise. Component (a) Ceramide NDS 1.00 parts by mass Cholesterol 0.75 parts by mass Ingredient (b) Decaglyceryl monomyristate 4.50 parts by mass 1,3-butylene glycol 20.00 parts by mass Glycerin 10.00 parts by mass Ingredient (c) Water 63.75 parts by mass

[0054] (Comparative Example 1) A ceramide-free preparation (Placebo=Blk) was prepared with the same formulation as in Example 1, except that it did not contain ceramide NDS.

[0055] Example 2 A ceramide preparation (ceramide composition) was prepared using polyoxyethylene hydrogenated castor oil (HCO60) instead of decaglyceryl monomyristate in Example 1.

[0056] Example 3 A ceramide preparation (ceramide composition) was prepared using polyglyceryl (13) polyoxybutylene (14) stearyl ether in place of decaglyceryl monomyristate in Example 1.

[0057] (Comparative Example 2) A ceramide preparation (ceramide composition) was prepared by using ceramide NP instead of the ceramide NDS of Example 1.

[0058] (Test Example 1) Dilution of the ceramide proliferation promoter and quantification of the amount of ceramide permeation by filter paper filtration Before subjecting the produced ceramide preparation to a cell culture test, the amount of ceramide in a diluted solution of the ceramide preparation in phosphate buffered saline was quantified before and after filtering through a syringe filter.

[0059] Preparation of internal standard solution: The internal standard solution was prepared by precisely weighing approximately 0.40 g of ethyl stearate (Nacalai Tesque, special grade, Nacalai standard) and dissolving it in tetrahydrofuran to make exactly 20 ml.

[0060] Creating a calibration curve: The calibration curve was prepared in the following manner. Approximately 50 g of (2S,3R)-2-octadecanoylaminooctadecane-1,3-diol reference standard (prepared by recrystallizing the product three times in ethanol and drying, free of related substances) was accurately weighed and diluted to 50 ml with tetrahydrofuran to prepare the standard stock solution. 1 ml, 2 ml, and 3 ml of the standard stock solution were accurately weighed, and 1 ml of the internal standard solution was added. Then, methanol was added to make a total of 10 ml. These were used as standard solutions. 20 μl of each of these solutions was tested by liquid chromatography under the following operating conditions. The peak area of ​​(2S,3R)-2-octadecanoylaminooctadecane-1,3-diol relative to the peak area of ​​the internal standard was calculated from the resulting chromatogram. A calibration curve was prepared by plotting this ratio on the vertical axis and the ratio of the mass of the (2S,3R)-2-octadecanoylaminooctadecane-1,3-diol reference standard relative to the mass of the internal standard on the horizontal axis.

[0061] Quantitation of ceramide permeation: Each ceramide preparation from Examples 1 to 3 was diluted 10-fold with phosphate-buffered saline. The following procedure was performed on the diluted solution before filtration and the diluted solution filtered through a syringe filter (Millipore, Millex-HV filter, 0.45 μm). 10.0 ml of the diluted solution was weighed out, and the solvent was removed in a rotary evaporator at 60°C for 15 minutes until the concentration reached 200-20 mmHg. 5 ml of tetrahydrofuran was added to the dried sample, which was then ultrasonically irradiated and heated to 60°C to obtain a suspension. This suspension was diluted to 10 ml with tetrahydrofuran, and 2 ml of the supernatant and 2 ml of the internal standard solution (internal standard: ethyl stearate) were added. The suspension was then diluted to 10 ml with methanol (Wako Pure Chemical Industries, liquid chromatograph grade) to prepare a test solution. A 20 μl sample solution was tested by liquid chromatography to determine the ratio of the peak area of ​​(2S,3R)-2-octadecanoylaminooctadecane-1,3-diol to the peak area of ​​the internal standard substance. The mass ratio was then calculated using a calibration curve prepared in advance, and the amount was quantified using the following formula: Calculation formula: Amount of (2S,3R)-2-octadecanoylaminooctadecane-1,3-diol (mg) = A × mass ratio obtained from the calibration curve A: Amount (mg) of internal standard substance (ethyl stearate) in 1 ml of internal standard solution

[0062] The high-performance liquid chromatograph was used under the following conditions: detector: ultraviolet absorption spectrophotometer (measurement wavelength: 210 nm), column: Inertsil ODS-3 (Nacalai Tesque, 4.6 mm x 25 cm), column temperature: 40°C, mobile phase: methanol, flow rate: 1.0 ml / min.

[0063] The amount of ceramide that had passed through (permeability) after filtration is shown in Table 1 below.

[0064] [Table 1]

[0065] From the above results, it was found that by including decaglyceryl monomyristate, a ceramide proliferation promoter that maintains a fine particle size can be prepared.

[0066] (Test Example 2) Ceramide proliferation test <Human keratinocyte culture and formulation addition test> Experiments were performed using cultured human keratinocytes (KCs) at undifferentiated and differentiated stages. KCs were cultured in serum-free KC growth medium containing 0.07 mM calcium. When KCs occupied approximately 60-70% of the total surface area of ​​the culture dish (approximately 60-70% confluence), the cells were harvested and used as undifferentiated cells. KCs were cultured in serum-free KC growth medium containing 0.07 mM calcium. When KCs occupied approximately 70-80% of the total surface area of ​​the culture dish (approximately 70-80% confluence), the medium was replaced with DMEM and Ham's F-12 (2:1, v / v) containing 10% fetal bovine serum, 10 μg / mL insulin, 0.4 μg / mL hydrocortisone, and 50 μg / mL vitamin C, containing 1.2 mM calcium, and cultured for 8 days. Next, the cells were cultured for 3 days in DMEM medium containing 10% fetal bovine serum containing 1.2 mM calcium, 10 μg / mL insulin, 0.4 μg / mL hydrocortisone, and 50 μg / mL vitamin C to obtain cultured human keratinocytes (LDK) in the late differentiation stage. Culture was performed for 10 days from Day 0 to Day 10 according to the process shown in Figure 2, and various ceramides were quantified on the final day. From Day 2 to Day 4, 6, 8, 9, and 10 of culture, the ceramide preparation (1% ceramide NDS solution) prepared in Example 1 was diluted with medium, filtered through a 0.45 μm filter paper, and 15.9 μL, 79.6 μL, and 397.7 μL (= 10 μM, 50 μM, and 250 μM) were added, respectively. In addition, 79.6 μL of the ceramide-free Blk solution prepared in Comparative Example 1 was added and cultured.

[0067] <Ceramide proliferation test> 100 μg of each culture medium prepared above and 100 pmol of a mixture of internal standards (C17 (carbon number 17)-ceramide NS=N-octadecanoylamino-C17 sphingosine, C17-sphingosine, and C17-dihydrosphingosine) were added to a mixture of 0.1 N aqueous HCl:chloroform:methanol (volume ratio 1:2:1) and stirred. The lower organic phase was dried under reduced pressure, and this extraction and drying procedure was repeated twice. The resulting residue was dissolved in 200 μl of an equal volume mixture of methanol and acetonitrile and analyzed by liquid chromatography-tandem mass spectrometry (LC-ESI-MS / MS) system (API 3200 QTRAP mass, ABCIEX). Optimization of analytical accuracy: A mixture of ceramide standards (ceramide NDS with sphingosine base carbon numbers 14 to 26, and ceramide NS) was used, and all ion source parameters and ionization conditions were adjusted to optimize analytical accuracy. A 10 μL aliquot of the extracted sample was analyzed by HPLC (Shiseido HTS HPLC System) on a reversed-phase KINETEX C18 column (2.1 x 50 mm, ID = 2.6 μm). The column was pre-equilibrated with solvent A (MeOH: 0.05% formic acid solution: 80:20). Lipids were dissolved in solvent B (2-propanol: 0.05% formic acid solution in methanol: 99:1). Mass spectra were detected in positive mode by electrospray ionization using a gradient at a flow rate of 0.3 mL / min. 5 mM ammonium formate was added to both solvents A and B for buffering and to improve sensitivity. In the first stage of MS / MS, precursor ions m / z [M+H]+ of various ceramide components were captured, and in the second stage, they were decomposed by collision, and the product ions m / z obtained by decomposition in the third stage were detected. The various ceramide species were quantified using Analyst 1.5.1 (Applied Biosystems) by comparison with a calibration curve obtained from an internal standard substance, and the amount of ceramide in the stratum corneum was calculated as pmol / g. The monitoring parameters for various ceramides are shown in Table 2.

[0068] [Table 2]

[0069] (Test Results 2-1) The quantitative results of ceramide EOS are shown in FIG. As is clear from Figure 3, it was confirmed that in the culture system supplemented with ceramide NDS, ceramide EOSs having ω-hydroxy acid amide bonds with carbon numbers of 30 and 32, esterified with linoleic acid at the ω-position, significantly increased. Note that # indicates a significant difference of p<0.01 compared to differentiated keratinocyte cultured cells (LDK) not supplemented with ceramide NDS.

[0070] (Test Results 2-2) The quantitative results of ceramide NSs are shown in FIG. As is clear from Figure 4, it was confirmed that in the culture system supplemented with ceramide NDS, there was a significant increase in ceramide NSs, which have an amide bond with an acyl chain length of 14 to 26 and a double bond at the 4-position of the sphingosine base. Note that # indicates a significant difference of p<0.01 compared to differentiated cultured cells (LDK) not supplemented with ceramide NDS, and * indicates a significant difference of p<0.01 compared to undifferentiated cells (UDK).

[0071] (Test Results 2-3) The quantitative results of ceramide NDSs are shown in FIG. As is clear from Figure 5, it was confirmed that in the culture system to which ceramide NDS was added, there was a significant increase in ceramide NDSs with different acyl chain lengths, from 14 to 26. Note that # indicates a significant difference of p<0.01 compared to differentiated cultured cells (LDK) to which ceramide NDS was not added, and * indicates a significant difference of p<0.01 compared to undifferentiated cells (UDK).

[0072] The above test results revealed that the addition of a ceramide preparation containing ceramide NDS (acyl chain length C18) not only increases the proliferation of ceramide NDS with different acyl chain lengths, but also a variety of ceramide species such as ceramide NS and even ceramide EOS. In addition, the ceramide NP preparation prepared in Comparative Example 2 did not show any tendency for significant proliferation of diverse ceramide species.

[0073] Example 4 According to a conventional method, 100 g of a skin lotion for increasing ceramide containing 0.1 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0074] [Table 3]

[0075] Example 5 According to a conventional method, 100 g of a ceramide-increasing beauty serum containing 0.25 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0076] [Table 4]

[0077] Example 6 According to a conventional method, 100 g of an emollient cream for increasing ceramide containing 0.05 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0078] [Table 5]

[0079] Example 7 According to a conventional method, 100 g of emollient milk for increasing ceramide containing 0.05 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0080] [Table 6]

[0081] Example 8 According to a conventional method, 100 g of a conditioning shampoo for increasing ceramide containing 0.05 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0082] [Table 7]

[0083] Example 9 According to a conventional method, 100 g of a hair rinse for ceramide proliferation containing 0.05 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0084] [Table 8]

[0085] Example 10 According to a conventional method, 100 g of a hair conditioner for increasing ceramide containing 0.05 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0086] [Table 9]

[0087] Example 11 According to a conventional method, 100 g of a hair tonic for increasing ceramide containing 0.05 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0088] [Table 10]

[0089] Example 12 According to a conventional method, 100 g of a liquid bath additive for increasing ceramide containing 0.05 mass % of ceramide NDS was produced according to the formulation shown in the table below (units in the table: mass %).

[0090] [Table 11]

[0091] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2020-40142) filed on March 9, 2020, the contents of which are incorporated herein by reference.

Claims

1. A ceramide proliferation promoter containing, as an active ingredient, a ceramide represented by the following general formula (1): 【Chemical 1】 (In the formula, R １ represents a monovalent saturated hydrocarbon group having 13 to 21 carbon atoms, and Z represents an acyl group having 14 to 24 carbon atoms.

2. 2. The ceramide proliferation promoter according to claim 1, wherein the ceramide represented by the general formula (1) is a ceramide represented by the following general formula (2): 【Chemistry 2】 (In the formula, R １ represents a monovalent saturated hydrocarbon group having 13 to 21 carbon atoms, and Z represents an acyl group having 14 to 24 carbon atoms.

3. 3. The ceramide proliferation promoter according to claim 1, wherein the ceramide to be proliferated is a ceramide represented by the following general formula (3): 【Chemistry 3】 (In the formula, R ２ represents a monovalent hydrocarbon group having 13 to 21 carbon atoms which may have a carbon-carbon double bond and / or a hydroxyl group, R ３ represents a divalent saturated hydrocarbon group having 13 to 31 carbon atoms which may have a hydroxyl group, Y represents a hydrogen atom or an —O—C(═O)— bond, and R ４ is absent when Y is a hydrogen atom, and represents a monovalent hydrocarbon group having 15 to 25 carbon atoms which may have a carbon-carbon double bond when Y is an —O—C(═O)— bond.

4. 3. The ceramide proliferation promoter according to claim 1, wherein the ceramide to be proliferated is a ceramide represented by the following general formula (4): 【Chemistry 4】 (In the formula, R ５ represents a monovalent hydrocarbon group having 13 to 21 carbon atoms and a carbon-carbon double bond, and X represents an acyl group having 14 to 24 carbon atoms.

5. The ceramide proliferation promoter according to any one of claims 1 to 4, wherein the diameter of the ceramides serving as the active ingredient is 0.45 µm or less.

6. A method for increasing and / or supplementing various ceramide species in the stratum corneum of the skin by applying the ceramide proliferation promoter according to any one of claims 1 to 5.

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