JP7560985B2 - Solubilizing composition for poorly water-soluble substances - Google Patents

Description

The present invention relates to a solubilizing composition for poorly water-soluble substances, which contains a specific polyglycerol fatty acid ester having an HLB value of 13 or more, a specific ester oil, and a polyhydric alcohol, and which can easily and transparently solubilize a poorly water-soluble substance by mixing the poorly water-soluble substance with water at a temperature of 20 to 50°C during preparation of the cosmetic. The present invention also relates to a cosmetic with a reduced content of surfactant used to solubilize the poorly water-soluble substance in water. Furthermore, the present invention relates to a method for producing a cosmetic, which includes a step of mixing a poorly water-soluble substance and a solubilizing composition for poorly water-soluble substances with water at a temperature of 20 to 50°C.

In cosmetics, such as lotions and beauty serums, which are generally assumed to be transparent, poorly water-soluble substances such as fragrances, essential oils, vegetable oils, hydrocarbon oils, ester oils, and fat-soluble vitamins are usually solubilized by a solubilizer. Polyoxyethylene surfactants have been commonly used as solubilizers because of their strong solubilizing power, and examples of such solubilizers include polyoxyethylene derivatives such as polyoxyethylene cetyl ether, polyoxyethylene sorbitan monooleate, and polyoxyethylene hydrogenated castor oil. However, these polyoxyethylene derivatives have problems such as skin irritation, eye mucosa irritation, and sensitization, depending on the amount of the polyoxyethylene derivatives. Furthermore, because they have ethylene oxide chains as hydrophilic groups, there are safety issues such as the elution of formalin due to the decomposition of the ethylene oxide chains. In addition, because fragrances, essential oils, and vegetable oils are highly polar, a large amount of surfactant is used to solubilize them. As a result, they have the disadvantage of being difficult to use when applied to the skin as cosmetics.

In order to increase the stability of cosmetics in which poorly water-soluble substances have been solubilized, a preparation method using polyglycerol fatty acid esters and ethanol at 60 to 80°C has been proposed (see, for example, Patent Documents 1, 4, and 5). However, ethanol has problems in that it can cause skin irritation, eye mucosa irritation, and sensitization depending on the amount used. In addition, since fragrances and essential oils have high polarity and low boiling points, when they are solubilized by heating to 60 to 80°C, the aromatic components of the fragrances and essential oils volatilize, causing problems such as a decrease in the fragrance-imparting properties of the cosmetics and a change in the quality of the aroma.

In addition, the use of polyglycerol fatty acid esters has been proposed to improve safety in terms of skin irritation (see, for example, Patent Document 2). However, the polyglycerol fatty acid esters used in these reports require stirring with strong shearing force to prepare transparent cosmetics, and equipment with high shearing force such as high-pressure homogenizers has been used. However, when processed with equipment with high shearing force, the solution temperature easily exceeds 50°C, causing the volatilization of fragrances and essential oils, resulting in problems such as a decrease in the fragrance-imparting properties of the cosmetics and deterioration of the fragrance. Furthermore, equipment with high shearing force is expensive and complicated to use, making it difficult to use in practice.

A method using polyglycerol fatty acid esters has also been proposed (see, for example, Patent Document 3). This method uses a mixture of polyglycerol condensed ricinoleic acid ester and polyglycerol oleic acid ester and/or polyglycerol lauric acid ester, and is a good method for obtaining cosmetics in which poorly water-soluble substances are solubilized. However, to obtain a transparent cosmetic using this method, it is necessary to mix a large amount of surfactant (2.5 to 3.0 g per 1 g of poorly water-soluble substance), and the obtained cosmetic has problems with usability when applied to the skin, such as weight of spread and stickiness after application.

In light of the above, there has been a demand for the development of a solubilizing composition that can easily and transparently solubilize poorly water-soluble substances by mixing them in small amounts in water at temperatures between 20 and 50°C during cosmetic preparation without using polyoxyethylene surfactants, ethanol, or equipment with high shear forces, and that provides cosmetic preparations with good temperature stability over time.

JP 2015-44780 A JP 2013-224290 A JP 2010-100586 A JP 2014-122196 A JP 2015-86147 A

The problem that the present invention aims to solve is to provide a solubilizing composition for poorly water-soluble substances that solves the above problems. That is, the present invention provides a solubilizing composition for poorly water-soluble substances that contains a specific polyglycerol fatty acid ester, which has excellent solubilizing power and can be used to easily and transparently solubilize poorly water-soluble substances such as fragrances and essential oils by mixing them in small amounts in water at a temperature of 20 to 50°C, and which provides a cosmetic product with good temperature stability over time and good usability when applied to the skin, such as little spread or stickiness, and also has good fragrance-imparting properties.

As a result of intensive research to solve the above problems, the present inventors have found that a solubilizing composition containing a specific content (weight ratio) of a polyglycerol fatty acid ester composed of unsaturated and/or branched fatty acids having 18 carbon atoms, the polyglycerol having a degree of polymerization of 5 to 20 and an HLB value of 13 or more, a polyglycerol fatty acid ester composed of fatty acids having 10 to 14 carbon atoms, the polyglycerol having a degree of polymerization of 5 to 20 and an HLB value of 13 or more, an ester oil composed of a fatty acid having 10 or less carbon atoms and an alcohol having 9 or less carbon atoms, and a polyhydric alcohol can solve the above problems by mixing a poorly water-soluble substance in water at a temperature of 20 to 50°C during preparation of a cosmetic product, and thus has completed the present invention.

That is, the present invention provides the following components (A) to (D):
(A) a polyglycerol fatty acid ester which is composed of unsaturated and/or branched fatty acids having 18 carbon atoms, the degree of polymerization of the constituting polyglycerol being 5 to 20, and the HLB value being 13 or more;
(B) a polyglycerol fatty acid ester composed of fatty acids having 10 to 14 carbon atoms, the degree of polymerization of the constituting polyglycerol being 5 to 20, and the HLB value being 13 or more;
(C) an ester oil composed of a fatty acid having 10 or less carbon atoms and an alcohol having 9 or less carbon atoms;
The solubilizing composition for a poorly water-soluble substance contains (D) a polyhydric alcohol, and has a weight ratio of (A):(B) of 7:1 to 15:1, a weight ratio of {(A)+(B)}:(C) of 8:1 to 15:1, and a weight ratio of {(A)+(B)}:(D) of 1:3 to 1:6. The solubilizing composition for a poorly water-soluble substance is also provided, in which (A)+(B) is 13% by weight or more based on the total weight of the solubilizing composition. Furthermore, the solubilizing composition for a poorly water-soluble substance is used to provide a cosmetic in which the content of a surfactant used to solubilize the poorly water-soluble substance in water is reduced. Furthermore, a method for producing a cosmetic is provided, which includes a step of mixing a poorly water-soluble substance and a solubilizing composition for a poorly water-soluble substance in water at a temperature of 20 to 50° C.

The solubilizing composition for poorly water-soluble substances of the present invention can be incorporated in small amounts into cosmetics, and by mixing poorly water-soluble substances with water at temperatures of 20 to 50°C, it can easily and transparently solubilize them. This makes it possible to solubilize fragrances, essential oils, etc. without using polyoxyethylene surfactants or ethanol, which may cause skin irritation, or equipment with high shear forces, and it is possible to develop cosmetics that have good temperature stability over time, and that are easy to use and have good fragrance properties when applied to the skin.

The method for preparing polyglycerin constituting the polyglycerin fatty acid ester of components (A) and (B) of the present invention is not particularly limited, but examples thereof include dehydration polymerization of glycerin, ring-opening polymerization using glycerin analogues such as glycidol and epichlorohydrin, and diglycerin cross-linking using dichloropropanol. Other examples include methods for preparing polyglycerin by distillation purification or column chromatographic separation.

The degree of polymerization of the polyglycerin constituting the polyglycerin fatty acid ester of components (A) and (B) of the present invention is the degree of polymerization of the polyglycerin calculated from the hydroxyl value by the terminal group analysis method. More specifically, it is the degree of polymerization calculated from (Equation 1) and (Equation 2).

(Formula 1) Degree of polymerization = (112.2 x 103 - 18 x hydroxyl value) / (74 x hydroxyl value - 56.1 x 103)
(Formula 2) Hydroxyl value = (a - b) x 28.05 / sample amount (g)
a: Amount of 0.5N potassium hydroxide solution consumed in the blank test (ml)
b: Amount of 0.5N potassium hydroxide solution consumed in this test (ml)
The hydroxyl value in the above formula (1) is calculated according to formula (2) in accordance with "Standard Methods for Analysis of Fats, Oils and Related Materials (I) 1996 Edition, Established by the Japan Oil Chemists'Society," edited by the Japan Oil Chemists' Society.

The degree of polymerization of the polyglycerin constituting the polyglycerin fatty acid ester of components (A) and (B) of the present invention is 5 to 20, preferably 6 to 10. Polyglycerin fatty acid esters composed of polyglycerin with a lower degree of polymerization are not preferred because they have insufficient hydrophilicity, have a reduced ability to solubilize poorly water-soluble substances, and impair transparency when added to cosmetics, etc. Furthermore, polyglycerin fatty acid esters composed of polyglycerin with a degree of polymerization higher than 20 are not preferred because they have a significantly higher content of free polyglycerin, have insufficient hydrophilicity of the polyglycerin fatty acid ester itself, have a reduced ability to solubilize poorly water-soluble substances, and impair transparency when added to cosmetics, etc.

The cyclic content of polyglycerin constituting the polyglycerol fatty acid ester of components (A) and (B) of the present invention refers to the content of glycerin cyclic units in the entire polyglycerin detected by liquid chromatography-mass spectrometry (LC/MS). The analysis conditions are as follows.
(LC separation conditions)
Column: TSKgel α-2500 (7.8 x 300 mm) (aqueous polymer gel column)
Temperature: 40°C
Eluent: water/acetonitrile=7/3
Flow rate: 0.8ml/min
Injection volume: 10 μl (sample concentration 100 ppm)
Analysis time: 20 minutes (MS analysis conditions)
Apparatus: LCQ (Thermoquest, ion trap type)
Ionization mode: APCI (Atmospheric Pressure Chemical Ionization) negative
Measurement range: m / z = 90-2000
Intensity ratio measurement: This is a mass spectrum analysis method that shows the relative intensity distribution of each m/z at any time.

The method for preparing the polyglycerol fatty acid ester in the present invention is not particularly limited, but examples thereof include a method in which polyglycerol and a fatty acid are heated in the presence of an acid catalyst (phosphoric acid, p-toluenesulfonic acid, etc.) or an alkali catalyst (caustic soda, etc.) or without a catalyst while removing water, preferably at 100 to 300°C, more preferably at 120 to 260°C. Note that a method in which an ester of a fatty acid, fat or oil, etc. is used instead of a fatty acid and an ester exchange reaction with polyglycerol is also included. Another example is a method using an addition polymerization reaction of glycidol to a fatty acid. The preparation of the polyglycerol fatty acid ester may be carried out in the presence of an inert gas. The polyglycerol fatty acid ester thus obtained may be purified according to the purpose by decolorization treatment using activated carbon or activated clay, deodorization treatment under reduced pressure using steam, nitrogen, etc. as a carrier gas, washing with an acid or alkali, molecular distillation, extraction or fractionation with an organic solvent, chromatographic separation using a column filled with a synthetic adsorbent or gel filtration agent, etc.

In the present invention, the HLB value refers to a value measured by the Atlas method of the following formula 3.
(Formula 3) HLB=20(1-S/A)
S: Saponification value of polyglycerol fatty acid ester A: Neutralization value of raw material fatty acid

The polyglycerol fatty acid ester of component (A) in the present invention is composed of unsaturated and/or branched fatty acids having 18 carbon atoms, the degree of polymerization of the constituent polyglycerol is 5 to 20, and its HLB value is 13 or more, preferably 14 or more.

Generally, polyglycerol is a mixture with a distribution of polymerization degrees, and contains not only linear bonds but also cyclic bodies formed by dehydration condensation within the molecule. The content of cyclic bodies increases as the degree of polymerization of polyglycerol increases, so it is known that it is difficult to obtain a polyglycerol with a high degree of polymerization that has a low content of cyclic bodies. If a large amount of cyclic bodies formed by dehydration condensation within the molecule is contained, the hydrophilicity of the polyglycerol decreases. In polyglycerol fatty acid esters composed of such polyglycerols, it is difficult to take into account the cyclic bodies and reflect the decrease in hydrophilicity in the HLB value, which generally reflects the hydrophilicity of surfactants. Therefore, in the polyglycerol fatty acid esters of component (A) composed of polyglycerols with a high degree of polymerization, it is preferable that the polyglycerols contain a small amount of cyclic bodies.

The polyglycerol fatty acid ester of component (A) in the present invention is, from the viewpoint of hydrophilicity, a polyglycerol fatty acid ester composed of polyglycerol having a cyclic content of preferably 30% by weight or less (hereinafter also referred to as "component A1"), or a polyglycerol fatty acid ester composed of polyglycerol in which the content of polyglycerols having a degree of polymerization of 5 or more is preferably 80% by weight or more of the total polyglycerols constituting the polyglycerols and the content of polyglycerols having a degree of polymerization of 5 is preferably 30% by weight or more of the total polyglycerols constituting the polyglycerols (hereinafter also referred to as "component A2").

The fatty acids constituting the polyglycerol fatty acid ester of component (A) in the present invention are substances containing carboxylic acids as functional groups, which are obtained by hydrolyzing fats and oils extracted from natural animals and plants, and purifying them with or without separation. Examples of such fatty acids include, but are not limited to, isostearic acid, oleic acid, and ricinoleic acid.

The polyglycerol fatty acid ester of component (B) in the present invention is composed of fatty acids having 10 to 14 carbon atoms, the degree of polymerization of the constituting polyglycerol is 5 to 20, and its HLB value is 13 or more, preferably 14 or more.

The fatty acids constituting the polyglycerol fatty acid ester of component (B) in the present invention are substances containing carboxylic acids as functional groups, which are obtained by hydrolyzing fats and oils extracted from natural animals and plants, and purifying them with or without separation. Examples of such fatty acids include, but are not limited to, capric acid, lauric acid, and myristic acid.

In the content of the polyglycerol fatty acid esters of components (A) and (B) in the solubilizing composition for poorly water-soluble substances of the present invention, the weight ratio of (A):(B) is preferably 7:1 to 11:1, more preferably 7:1 to 8:1. In addition, (A) + (B) is preferably 13% by weight or more based on the entire solubilizing composition. A solubilizing composition for poorly water-soluble substances containing the polyglycerol fatty acid esters of components (A) and (B) at this content can easily and transparently solubilize a poorly water-soluble substance with an added amount of less than half the amount of the poorly water-soluble substance.

The total amount (A) + (B) of the polyglycerol fatty acid esters of components (A) and (B) in the solubilizing composition for poorly water-soluble substances of the present invention is preferably 0.5% by weight or less, more preferably 0.2% by weight or less, and even more preferably 0.18% by weight or less, based on the cosmetic. If the content of (A) + (B) exceeds 1.0% by weight based on the cosmetic, the cosmetic will have a poor feel when used (heavy spread, sticky feeling after application, etc.), which is not preferable.

Component (C) in the present invention, an ester oil composed of a fatty acid having 10 or less carbon atoms and an alcohol having 9 or less carbon atoms, is an oily component that is liquid at room temperature. There are no particular limitations on the type of component as long as it is usable as a cosmetic ingredient, but examples include at least one selected from the group consisting of diisopropyl adipate, dicaprylyl carbonate, isononyl isononanoate, tri(caprylic/capric acid) glycerin ester, tri-2-ethylhexanoic acid glycerin ester, etc.

The content of component (C) in the solubilizing composition for poorly water-soluble substances of the present invention is 8:1 to 15:1, preferably 10:1 to 14:1, in terms of the weight ratio of the sum of the polyglycerol fatty acid esters of components (A) and (B) (A) + (B) to the ester oil of component (C). Furthermore, the content of the ester oil of component (C) is preferably 0.05% by weight or less based on the cosmetic.

The polyhydric alcohol of component (D) in the present invention is a polyhydric alcohol that is liquid at room temperature and is not particularly limited as long as it is used as a cosmetic raw material, but examples thereof include at least one selected from the group consisting of propylene glycol, dipropylene glycol, ethylene glycol, diethylene glycol, polyethylene glycol, isoprene glycol, 1,3-butylene glycol, pentanediol, glycerin, diglycerin, triglycerin, polyglycerin, trimethylolpropane, erythritol, pentaerythritol, sorbitol, maltitol, lactose, fructose, maltose, sorbitan, etc., and is preferably glycerin or diglycerin, and more preferably glycerin.

The content of component (D) in the solubilizing composition for poorly water-soluble substances of the present invention is 1:3 to 1:6, preferably 1:4 to 1:5, in terms of the weight ratio of the sum of the polyglycerol fatty acid esters of components (A) and (B) (A) + (B) to the polyhydric alcohol of component (D).

The poorly water-soluble substance in the present invention is a poorly water-soluble substance that is liquid at room temperature and is not particularly limited as long as it is used as a cosmetic raw material, but examples thereof include fragrances, essential oils, vegetable oils and fats, and fat-soluble vitamins. Examples of fragrances include hydrocarbon fragrances such as limonene, alcohol fragrances such as linalool, geraniol, and menthol, aldehyde fragrances such as citral, ketone fragrances such as β-ionone, and phenol fragrances such as eugenol. Examples of essential oils include vegetable fragrances such as lavender oil, eucalyptus oil, rose oil, jasmine oil, peppermint oil, anise oil, rosemary oil, and bergamot oil, as well as musk, leopard tree, sea lily, and nautilus. Examples of vegetable oils include avocado oil, almond oil, olive oil, macadamia nut oil, castor oil, camellia oil, jojoba oil, sesame oil, safflower oil, soybean oil, persic oil, cottonseed oil, and sunflower oil. Other examples include fragrances such as blended fragrances in which vegetable fragrances, animal fragrances, and synthetic fragrances are blended according to purpose, and fat-soluble vitamins such as vitamin E such as tocopherol acetate, α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, α-tricoenol, β-tricoenol, γ-tricoenol, and δ-tricoenol, and vitamin A such as retinol and β-carotene. In addition to these, fragrances and fat-soluble vitamins used in cosmetics can also be used, and preferably vegetable fragrances and synthetic fragrances called essential oils. These poorly water-soluble substances may be used alone or in a mixture of two or more.

The content of the poorly water-soluble substance in the cosmetic of the present invention is preferably 0.01 to 1.0% by weight. In addition, if the content of the fragrance or essential oil as the poorly water-soluble substance is too high, the content of the surfactant for solubilizing them will be high, which may inhibit the volatilization of the fragrance components during use. Taking these points into consideration, it is desirable to select the content of the fragrance and essential oil in the cosmetic appropriately according to the type of fragrance used, etc.

The cosmetic material in the present invention is a material that contains a poorly water-soluble substance, and includes, but is not limited to, examples thereof, such as skin lotion, beauty essence, hair lotion, hair tonic, cologne, body sheet, wet tissue, mouthwash, shampoo, and body soap.

In addition to the above-mentioned components, the cosmetic composition of the present invention may contain surfactants, aqueous gelling agents, ultraviolet absorbers, powders, antioxidants, preservatives, fragrances, colorants, chelating agents, cooling agents, thickeners, plant extracts, vitamins, neutralizing agents, moisturizing agents, anti-inflammatory agents, pH adjusters, amino acids, etc., as appropriate, provided that the effects of the present invention are not impaired.

The method for producing the solubilizing composition for poorly water-soluble substances in the present invention is not particularly limited, but preferably includes a step of mixing (A) to (D) at a temperature of 20 to 50°C. From the viewpoint of uniformity of (A) to (D), the temperature is more preferably 40 to 50°C.

The method for producing the cosmetic of the present invention is not particularly limited, but preferably includes a step of mixing the poorly water-soluble substance and the solubilizing composition for the poorly water-soluble substance in water at a temperature of 20 to 50°C. It is more preferable to mix the poorly water-soluble substance and the solubilizing composition for the poorly water-soluble substance at a temperature of 20 to 50°C and then mix them with water. This step allows the poorly water-soluble substance to be easily and transparently solubilized in water. In terms of the fragrance and stability of the poorly water-soluble substance, the temperature of the step of mixing the poorly water-soluble substance and the solubilizing composition for the poorly water-soluble substance in water is more preferably 25 to 40°C in any step. Furthermore, the cosmetic of the present invention can be obtained by blending ingredients of a lotion or beauty serum.

The equipment having high shear force in the present invention is not particularly limited, but examples thereof include a homomixer, a disperser mixer, an ultramixer, a microfluidizer, a starburst, etc., and by using the solubilizing composition for poorly water-soluble substances of the present invention, it becomes possible to manufacture cosmetics without using such equipment having high shear force in the cosmetic manufacturing process.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these in any way.

In the present invention, the polyglycerol fatty acid esters of component (A) used were those listed in Tables 1 and 2. The polyglycerol fatty acid esters of component (B) used were those listed in Table 3. The ester oils of component (C) used were those listed in Table 4. The poorly water-soluble substances used were those listed in Table 5.

Example 1 and Comparative Example 1
Solubilizing compositions for poorly water-soluble substances, Products 1 to 38 of the present invention, and Comparative Products 1 to 21, were prepared in the blending ratios shown in Tables 6 to 11.
Then, the poorly water-soluble substance and Present Products 1 to 38 or Comparative Products 1 to 21 were mixed at 25 to 50° C. in the blending ratios shown in Tables 6 to 11. The poorly water-soluble substance was then mixed with water at 25° C. so that the concentration was 0.1% by weight, thereby preparing cosmetics containing Present Products 1 to 38 or Comparative Products 1 to 21.

Example 2 and Comparative Example 2
Solubilizing compositions for poorly water-soluble substances, Products 39 and 40 of the present invention, and Comparative Product 22 were prepared using the blending ratios shown in Table 12.
Thereafter, the poorly water-soluble substance was mixed with Products 2, 39, and 40 of the present invention or Comparative Products 3 and 22 at the blending ratios and preparation temperatures shown in Table 12. Then, the poorly water-soluble substance was mixed with water at the same preparation temperature as when the products of the present invention and the comparative products were mixed so that the poorly water-soluble substance was 0.1% by weight, thereby preparing cosmetics containing Products 2 and 39 of the present invention or Comparative Products 3 and 22.

Test Example 1 (Appearance Transparency)
The cosmetics containing the present invention products 1 to 40 or the comparative products 1 to 22 were measured for transmittance at a wavelength of 550 nm using a spectrophotometer (Shimadzu Corporation: UV-2600), and a transmittance of 94% or more was evaluated as transparent. These results are shown in Tables 6 to 12.

Test Example 2 (Temperature Stability)
Cosmetics containing invention products 1 to 40 or comparative products 1 to 22 were exposed to 50°C or -5°C for one month, and the transmittance was measured under the conditions of Test Example 1 and evaluated according to the following evaluation criteria. In addition, based on the evaluation results at each temperature, an overall evaluation was performed according to the following evaluation criteria. The results are shown in Tables 6 to 12.

(Evaluation criteria at each temperature)
◎: Transmittance of 98.0% or more ○: Transmittance of 96.0% or more and less than 98.0% △: Transmittance of 94.0% or more and less than 96.0% ×: Transmittance of less than 94.0%

(Overall evaluation criteria)
◎: Transmittance of 98.0% or more at all temperatures ○: Transmittance of 96.0% or more at all temperatures, and less than 98.0% at any temperature △: Transmittance of 94.0% or more at all temperatures, and less than 96.0% at any temperature ×: Transmittance of less than 94.0% at any temperature

Test Example 3 (Fragrance)
Cosmetics containing the present invention products 2, 39, and 40 or the comparative products 3 and 22 were subjected to a sensory evaluation of fragrance by 20 highly skilled female panelists. They were rated on a 5-point scale of 1: very bad, 2: bad, 3: slightly bad, 4: good, and 5: very good, and the average score of the 20 panelists was calculated. The average score was evaluated according to the following evaluation criteria, and the results are shown in Table 12.

(Evaluation Criteria)
◎: Average value of 4.5 points or more 〇: Average value of 4.0 points or more and less than 4.5 points △: Average value of 3.0 points or more and less than 4.0 points ×: Average value of less than 3.0 points

The cosmetics containing the product of the present invention had good transparency in appearance, temperature stability over time, and fragrance imparting ability. On the other hand, the cosmetics containing the comparative product had poor transparency in appearance, temperature stability over time, or fragrance imparting ability.

Formulation example 1 (lotion)
A lotion containing the product of the present invention was prepared according to the formulation shown in Table 13. The product 2 of the present invention and lavender oil were mixed at 30° C., and the remaining ingredients were then mixed at 25° C. to prepare the lotion. The product had good transparency in appearance, temperature stability over time, and usability when applied to the skin, such as spreadability and stickiness.

Formulation example 2 (serum)
A beauty essence containing the product of the present invention was prepared according to the formulation shown in Table 14. The beauty essence was prepared by mixing the product 2 of the present invention and lavender oil at 50° C., and then mixing the remaining ingredients at 40° C. The beauty essence had good transparency in appearance, temperature stability over time, and usability when applied to the skin, such as spreadability and stickiness.

Formulation example 3 (lotion)
A lotion containing the product of the present invention was prepared according to the formulation shown in Table 15. A beauty essence was prepared by mixing Product 2 of the present invention and lavender oil at 25° C., and then mixing the remaining ingredients at 25° C. The cosmetic essence had good transparency in appearance, temperature stability over time, and usability when applied to the skin, such as spreadability and stickiness.

Formulation example 4 (body sheet)
A body sheet containing the product of the present invention was prepared according to the formulation shown in Table 16. Product 38 of the present invention and FLORAL SOAP were mixed at 40° C., and the remaining ingredients were then mixed at 25° C. to prepare a body sheet. The transparency of the appearance, temperature stability over time, and usability when applied to the skin, such as spreadability and stickiness, were good.

The solubilizing composition for poorly water-soluble substances of the present invention has excellent solubilizing power, and by adding a small amount of the composition to a cosmetic, poorly water-soluble substances such as essential oils and fragrances can be mixed into water at a temperature of 20 to 50°C during preparation of the cosmetic, and easily and transparently solubilized without using equipment with high shear force. Furthermore, cosmetics containing the solubilizing composition for poorly water-soluble substances of the present invention have high transparency even when stored for a long time, and excellent temperature stability over time, so they have a good product image, and since they do not use polyoxyethylene-based surfactants or ethanol, which are of concern for skin irritation, they are highly safe and can be highly evaluated in the market, and therefore have great industrial applicability.

Claims (4)

A solubilizing composition for a poorly water-soluble substance, wherein the poorly water-soluble substance is at least one selected from the group consisting of fragrances and essential oils, and contains the following (A) to (D), wherein the weight ratio of (A):(B) is 7:1 to 15:1, the weight ratio of {(A)+(B)}:(C) is 8:1 to 15:1, and the weight ratio of {(A)+(B)}:(D) is 1:3 to 1:6.
(A) A polyglycerol fatty acid ester composed of unsaturated and/or branched fatty acids having 18 carbon atoms, the polyglycerol having a degree of polymerization of 5 to 20, and an HLB value of 13 or more. (B) A polyglycerol fatty acid ester composed of fatty acids having 10 to 14 carbon atoms, the polyglycerol having a degree of polymerization of 5 to 20, and an HLB value of 13 or more. (C) An ester oil composed of a fatty acid having 10 or less carbon atoms and an alcohol having 9 or less carbon atoms. (D) A polyhydric alcohol. The solubilizing composition for poorly water-soluble substances according to claim 1, wherein (A) + (B) is 13% by weight or more based on the total solubilizing composition. A cosmetic preparation containing the solubilizing composition for poorly water-soluble substances according to claim 1 or 2. The method for producing the cosmetic according to claim 3, characterized by comprising a step of mixing the poorly water-soluble substance according to claim 1 and the solubilizing composition for poorly water-soluble substances according to claim 1 or 2 with water at a temperature of 20 to 50°C.