Emulsifying preparations, aqueous cosmetics, food and beverages, and pharmaceutical compositions

Abstract

The present invention provides an emulsifiable preparation that has little influence on the environment or human bodies, shows high storage stability over a long period of time and is smooth to the touch, an aqueous cosmetic containing the emulsifiable preparation, a food or beverage containing the emulsifiable preparation, and a pharmaceutical composition containing the emulsifiable preparation. Provided is the emulsifiable preparation that contains one or more aqueous components selected from the group consisting of water and alcohols, an oily component and microparticles comprising a polymer compound, wherein the microparticles contain cellulose acetate as the polymer compound and have an average particle size of 2-10 μm. Also provided are an aqueous cosmetic, a food or beverage and a pharmaceutical composition, each containing the emulsifiable preparation.

Description

Technical Field

[0001] The present disclosure relates to an emulsified preparation that has little impact on the environment and the human body, excellent long-term storage stability, and good skin feel, and an aqueous cosmetic, food or drink, or pharmaceutical composition containing the emulsified preparation. This application claims the priority of Japanese Patent Application No. 2020-088329 filed in Japan on May 20, 2020, the content of which is incorporated herein by reference.

Background Art

[0002] In recent years, as emulsification methods, methods using surfactants or solid particles are known. A surfactant is a general term for compounds having a hydrophilic moiety and a hydrophobic moiety in the molecule. Surfactants are used as a base material for stably mixing an aqueous phase component and an oil phase component. Surfactants are used, for example, in the production of detergents, emulsions, lotions, etc. The production volume of surfactants has been increasing with the development of the petrochemical industry, and it is said to be 14.09 million tons in 2017 (Non-Patent Document 1).

[0003] As an emulsification method using solid particles, Pickering emulsions have been proposed. A Pickering emulsion is an emulsion stabilized by solid particles adsorbed on a liquid-liquid interface. As the solid particles forming the Pickering emulsion, various powder particles such as inorganic particles (hydrophobic silica, clay minerals, iron oxide, carbon black) and organic particles (polymer latex, etc.) are used (Non-Patent Document 2). Further, Pickering emulsions using solid particles containing an acrylic polymer have been proposed. (Patent Document 1) Furthermore, an emulsification method using nano-sized fine particles has also been reported (Patent Document 2).

[0004] The safety of the above surfactants has long been regarded as a problem (Non-Patent Documents 3 and 4). As a typical surfactant, for example, sodium lauryl sulfate is available. Sodium lauryl sulfate is known to cause protein denaturation by binding to the hydrophobic part of the protein and bringing the charge of the hydrophilic part of sodium lauryl sulfate onto the protein surface (Non-Patent Document 5). [Prior art documents] [Patent Documents]

[0005] [Non-Patent Document 1] The Future of Surfactants to 2022(Smithers Apex,2017) [Non-Patent Document 2] Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 439, 20 December 2013, P23-34 [Non-Patent Document 3] DETERGENT & COSMETICS p.28 Vol.31 No.1 Jan. 2008 [Non-Patent Document 4] DETERGENT & COSMETICS p.11 Vol.25 No.4 Aug.2002 [Non-Patent Document 5] Okayama University of Science Bulletin, No. 50, Appl3-22 (2014) [Patent Document 1] Japanese Patent Publication No. 2019-202962 [Patent Document 2] Japanese Patent Publication No. 2009-161460 [Overview of the project] [Problems that the invention aims to solve]

[0006] When solid particles are used for emulsification, sufficient storage stability of the emulsifying formulation may not be achieved. Furthermore, when inorganic particles are used as solid particles, there is a problem of poor skin feel. When organic particles are used as solid particles, there are concerns about microplastic pollution of the oceans. For this reason, emulsification methods using biodegradable nanoparticles as solid particles have been devised. However, there are concerns about the potential risks inherent in nanoparticles themselves. Also, when emulsifying formulations containing nanoparticles are applied to the skin, the nanoparticles can get caught in wrinkles on the skin, resulting in a poor skin feel after application. For these reasons, emulsifying formulations containing solid particles have not been widely used in cosmetics and other products until now.

[0007] Therefore, the purpose of this disclosure is to provide an emulsifying formulation that has minimal impact on the environment and human body, excellent long-term storage stability, and a pleasant feel on the skin, as well as an aqueous cosmetic, food or beverage, or pharmaceutical composition containing the emulsifying formulation. [Means for solving the problem]

[0008] As a result of diligent research to achieve the above objectives, the present inventors have found that by using specific microparticles for the emulsification method, an emulsified formulation can be obtained that has minimal impact on the environment and the human body, excellent long-term storage stability, and a pleasant feel on the skin. This disclosure is completed based on these findings.

[0009] In other words, the present disclosure provides an emulsifying formulation comprising one or more aqueous components selected from the group consisting of water and alcohol, an oily component, and microparticles of a polymer compound, wherein the microparticles contain cellulose acetate as the polymer compound, and the average particle size of the microparticles is 2 to 10 μm.

[0010] The above alcohol may contain polyhydric alcohols.

[0011] The polyhydric alcohol may be 20% by weight or more relative to the total amount of alcohol.

[0012] The emulsifying preparation described above may further contain a thickening agent.

[0013] The emulsifying formulation described above may further contain a surfactant.

[0014] This disclosure provides an aqueous cosmetic, food or beverage, or pharmaceutical composition containing the emulsifying formulation described above. [Effects of the Invention]

[0015] According to the emulsifying formulation of this disclosure, the cellulose acetate contained in the microparticles is biodegradable. Therefore, the microparticles can reduce their impact on the environment and the human body. Furthermore, the average particle size of the microparticles is 2 to 10 μm. Therefore, the potential risks inherent in the nanoparticles themselves can be reduced, and an emulsifying formulation with excellent long-term storage stability and a good skin feel can be obtained. In addition, the emulsifying formulation of this disclosure can be suitably used as an aqueous cosmetic, food and beverage, or pharmaceutical composition. [Modes for carrying out the invention]

[0016] The following describes the forms for implementing this disclosure. Each configuration and combination thereof in each embodiment is an example, and additions, omissions, substitutions, and other modifications are possible as appropriate, without departing from the spirit of this disclosure. This disclosure is not limited by the embodiments, but is limited only by the scope of the claims.

[0017] (Emulsified preparation) The emulsifying preparation of the present disclosure (hereinafter, may also be referred to as "emulsifying preparation") is a Pickering emulsion. The emulsifying preparation is obtained by an emulsification method using micro-particles as solid particles. The emulsifying preparation includes an aqueous component, an oily component, and micro-particles. The micro-particles adsorb to the emulsification interface of the aqueous component and the oily component. The oily component is dispersed in the aqueous component in a state covered with the micro-particles. Thereby, the oily component can stably maintain a state of being uniformly dispersed in the aqueous component. Therefore, an emulsifying preparation excellent in storage stability can be obtained. Hereinafter, the micro-particles, the aqueous component, and the oily component will be described in detail.

[0018] (Micro-particles) In the emulsifying preparation of the present disclosure, the micro-particles of the polymer compound contain cellulose acetate as the polymer compound. Since cellulose acetate is a polymer compound, it is hardly absorbed from the skin or the intestinal wall and is safe for the human body. Further, in the long term, since it is a biodegradable polymer compound, it is decomposed even when released into the natural world, and the impact on the environment can be suppressed.

[0019] The content of the polymer compound contained in the micro-particles is preferably 60% by weight or more, more preferably 80% by weight or more, and still more preferably 95% by weight or more based on the total weight of the micro-particles. When the content of the polymer compound contained in the micro-particles is 60% by weight or more based on the total weight of the micro-particles, it becomes easier to obtain micro-particles with a regular particle shape.

[0020] Furthermore, the microparticles are not limited to cellulose acetate alone, but may contain one or more other polymer compounds. For example, the microparticles may be particles made of cellulose acetate coated with another polymer compound, or particles made of another polymer compound coated with cellulose acetate, or particles formed from a mixture of cellulose acetate and another polymer compound. By containing other polymer compounds, the microparticles can acquire properties that cellulose acetate alone does not possess. As a result, the emulsifying formulation can change, for example, its taste, color, texture, etc., depending on the application.

[0021] The cellulose acetate content in the microparticle polymer compound is preferably 40% by weight or more, more preferably 60% by weight or more, and even more preferably 80% by weight or more, based on the total weight of the polymer compound.

[0022] Other polymer compounds included in the microparticles are preferably biodegradable polymer compounds. Examples of biodegradable polymer compounds include polylactic acid, polyglycolic acid, polyaspartic acid, polyvinyl alcohol, polyhydroxyalkanoates, modified polyethylene terephthalate, starch (glucose polymer), cellulose derivatives other than cellulose acetate, polybutylene succinate compounds, polycaprolactone, and gelatin. Furthermore, when the emulsifying formulation is for food and beverage use, the other polymer compounds may be, for example, edible polysaccharides. Examples of polysaccharides include pullulan, gellan gum, xanthan gum, tamarind seed gum, locust bean gum, pectin, carrageenan, guar gum, gum arabic, dextran, dextrin, sodium chondroitin sulfate, sodium hyaluronate, and sodium alginate. Furthermore, when the emulsifying formulation is for cosmetic use, examples of other polymer compounds include polyvinylpyrrolidone, carboxyvinyl polymer, sodium polyacrylate, methacrylic acid copolymer, and polyethylene glycol.

[0023] The average particle size of the microparticles is 2 to 10 μm. The upper limit of the average particle size of the microparticles is preferably 8 μm, and more preferably 7 μm. The lower limit of the average particle size of the microparticles is preferably 4 μm, and more preferably 5 μm. When the average particle size of the microparticles is 2 to 10 μm, the microparticles do not get caught in wrinkles on the skin when the emulsifying formulation is applied to the skin, resulting in a good skin feel after application. Furthermore, when the average particle size of the microparticles is 2 to 10 μm, the storage stability of the emulsifying formulation is improved. Moreover, when the average particle size of the microparticles is 5 μm or more, the microparticles can impart a good feel to the emulsifying formulation through the ball bearing effect.

[0024] The average particle size can be measured using dynamic light scattering. Specifically, the procedure is as follows: First, a sample is prepared by suspending 100 ppm microparticles in pure water using an ultrasonic vibrator. Then, the average particle size can be measured by measuring the volume frequency particle size distribution using laser diffraction (Horiba, Ltd. "Laser Diffraction / Scattering Particle Size Distribution Analyzer LA-960", ultrasonic treatment for 15 minutes, refractive index (1.500, medium (water; 1.333)). The average particle size (nm and μm, etc.) referred to here is the particle size value corresponding to 50% of the integrated scattering intensity in this particle size distribution.

[0025] Microparticles containing cellulose acetate as a polymer compound (hereinafter sometimes referred to as cellulose acetate microparticles) can be prepared by the method shown below (see WO 2019 / 156116 A1). The method for producing cellulose acetate microparticles includes the steps of obtaining cellulose acetate impregnated with a plasticizer, obtaining a dispersion in which the cellulose acetate impregnated with the plasticizer is dispersed, and removing a water-soluble polymer from the obtained dispersion. Note that cellulose acetate microparticles are not limited to being prepared by the method shown below, and may also be prepared by other known methods.

[0026] The coefficient of particle size variation of the cellulose acetate microparticles in this disclosure is preferably 0% to 60%, and more preferably 2% to 50%. The coefficient of particle size variation (%) can be calculated by the standard deviation of particle size / average particle size × 100. When the coefficient of particle size variation of the cellulose acetate microparticles is 0% to 60%, the particle size of the cellulose acetate microparticles will be within a certain range. Therefore, when cellulose acetate microparticles are used in water-based cosmetics, the skin feel of the water-based cosmetics is improved.

[0027] The sphericity of the cellulose acetate microparticles in this disclosure is 0.7 or more and 1.0 or less, preferably 0.8 or more and 1.0 or less, and more preferably 0.9 or more and 1.0 or less. When the sphericity of the cellulose acetate microparticles is 0.7 or more and 1.0 or less, they have excellent skin feel. Therefore, when cellulose acetate microparticles are used in water-based cosmetics, the skin feel and soft-focus effect of the water-based cosmetics are improved.

[0028] Sphericity can be measured by the following method: Using images of cellulose acetate microparticles observed with a scanning electron microscope (SEM), the major and minor axes of 30 randomly selected particles are measured, the minor axis / major axis ratio of each particle is determined, and the average of these minor axis / major axis ratios is taken as the sphericity. The closer the sphericity is to 1, the more perfectly spherical the particle is considered to be.

[0029] (Step to obtain cellulose acetate impregnated with plasticizer) Cellulose acetate impregnated with a plasticizer is obtained by mixing cellulose acetate with a plasticizer. The total degree of acetyl substitution of cellulose acetate is preferably 0.7 to 2.9, more preferably 1.4 to less than 2.6, and even more preferably 2.0 to less than 2.6. When the total degree of acetyl substitution is 0.7 to 2.9, the cellulose acetate becomes less soluble in water, resulting in particles with high sphericity and sufficiently high biodegradability. Cellulose acetate with a total degree of acetyl substitution of 0.7 to 2.9 is produced by known methods for producing cellulose acetate. Examples of known methods for producing cellulose acetate include the so-called acetic acid method, in which acetic anhydride is used as the acetic acid agent, acetic acid as the diluent, and sulfuric acid as the catalyst.

[0030] The total degree of acetyl substitution in cellulose acetate can be measured by the following method. First, the total degree of acetyl substitution is the sum of the degrees of acetyl substitution at positions 2, 3, and 6 of the glucose ring of cellulose acetate. The degrees of acetyl substitution at positions 2, 3, and 6 of the glucose ring of cellulose acetate particles can be measured by NMR according to the method of Tezuka (Carbonydr. Res. 273, 83 (1995)). Specifically, the free hydroxyl groups of the cellulose acetate sample are propionally converted with propionic anhydride in pyridine. The resulting sample is dissolved in deuterated chloroform, and the 13C-NMR spectrum is measured. The carbon signals of the acetyl group appear in the region from 169 ppm to 171 ppm in the order of positions 2, 3, and 6 from the highest magnetic field, and the signals of the carbonyl carbons of the propionyl group appear in the region from 172 ppm to 174 ppm in the same order. The degree of acetyl substitution at positions 2, 3, and 6 of the glucose ring in the original cellulose acetate can be determined from the relative abundance of acetyl and propionyl groups at their respective positions. The degree of acetyl substitution can be analyzed using 1H-NMR in addition to 13C-NMR.

[0031] Furthermore, the total degree of acetyl substitution can be determined by converting the degree of acetic acid, which is determined according to the measurement method for the degree of acetic acid in ASTM:D-817-91 (Test methods for cellulose acetate, etc.), using the following formula. This is the most common method for determining the degree of substitution of cellulose acetate. DS=162.14×AV×0.01 / (60.052-42.037×AV×0.01) In the above formula, DS is the total degree of acetyl substitution, and AV is the degree of acetic acid (%). Note that the conversion value of substitution obtained will usually have a slight error compared to the NMR measurement value. If the converted value and the NMR measurement value differ, the NMR measurement value should be used. Furthermore, if the value differs depending on the specific NMR measurement method, the NMR measurement value obtained using Tezuka's method described above should be used.

[0032] The general procedure for measuring the degree of acetic acid according to ASTM:D-817-91 (Test method for cellulose acetate, etc.) is as follows: First, 1.9 g of dried cellulose acetate is accurately weighed and dissolved in 150 mL of a mixed solution of acetone and dimethyl sulfoxide (volume ratio 4:1). Then, 30 mL of 1N sodium hydroxide aqueous solution is added, and saponification is carried out at 25°C for 2 hours. Phenolphthalein is added as an indicator, and excess sodium hydroxide is titrated with 1N sulfuric acid (concentration factor: F). A blank test is then performed in the same manner as above, and the degree of acetic acid is calculated according to the following formula. Average degree of acetic acid (%) = {6.5 × (BA) × F} / W (In the formula, A represents the titration volume of 1N sulfuric acid in the sample (mL), B represents the titration volume of 1N sulfuric acid in the blank test (mL), F represents the concentration factor of 1N sulfuric acid, and W represents the weight of the sample.)

[0033] The plasticizer can be used without particular limitations as long as it has a plasticizing effect in the melt extrusion process of cellulose acetate. The plasticizer should preferably be at least one selected from the group consisting of: citric acid-based plasticizers including citric acid esters such as triethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate; glycerin ester-based plasticizers including glycerin alkyl esters such as triacetin, diacetin, and monoacetin; adipic acid-based plasticizers such as diisononyl adipate; and phthalic acid-based plasticizers such as ethyl phthalate and methyl phthalate. More preferably, at least one selected from the group consisting of triethyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, triacetin, and diisononyl adipate is selected, and even more preferably, at least one selected from the group consisting of acetyl triethyl citrate, triacetin, diacetin, and diethyl phthalate is selected. The plasticizer can be used individually or in combination of two or more of the above plasticizers.

[0034] The amount of plasticizer added is preferably more than 0 parts by weight and 40 parts by weight or less, more preferably 2 parts by weight and 40 parts by weight or less, even more preferably 10 parts by weight and 30 parts by weight or less, and most preferably 15 parts by weight and 20 parts by weight or less, based on 100 parts by weight of the total amount of cellulose acetate and plasticizer. By adding an amount of plasticizer that is more than 0 parts by weight and 40 parts by weight or less, based on 100 parts by weight of the total amount of cellulose acetate and plasticizer, the sphericity of the resulting cellulose acetate microparticles is increased.

[0035] The mixing of cellulose acetate and plasticizer can be carried out dry or wet using existing mixers such as Henschel mixers. When using a mixer, the temperature inside the mixer is preferably in the range of 20°C to less than 200°C. Maintaining a temperature of 20°C to less than 200°C prevents the melting of cellulose acetate. Alternatively, the mixing of cellulose acetate and plasticizer may be carried out by, for example, melt kneading. Melt kneading may be carried out in combination with mixing using a mixer, in which case it is preferable to mix using a mixer at a temperature of 20°C to less than 200°C first, and then perform melt kneading. This allows the plasticizer and cellulose acetate to blend more uniformly and in a shorter time. Consequently, the sphericity of the final prepared cellulose acetate microparticles increases, resulting in a better tactile feel and texture.

[0036] Melt mixing is performed by heating and mixing in an extruder. The mixing temperature (cylinder temperature) of the extruder is preferably in the range of 200°C to 230°C. The melting point of cellulose acetate is approximately 230°C to 280°C, depending on the degree of substitution. Here, cellulose acetate impregnated with a plasticizer has a lower plasticization temperature. Therefore, even if the mixing temperature of the extruder is in the range of 200°C to 230°C, a uniform mixture in which the cellulose acetate has been plasticized can be obtained. Note that the mixing temperature may be 200°C, for example, when using a twin-screw extruder. The mixture may be extruded in strand form and then formed into pellet form by hot cutting or other methods. In this case, the die temperature may be around 220°C, for example.

[0037] (Process for obtaining a dispersion) In the process of obtaining the dispersion, first, cellulose acetate impregnated with a plasticizer and a water-soluble polymer are kneaded together. The amount of water-soluble polymer added is preferably 55 parts by weight or more and 99 parts by weight or less, more preferably 60 parts by weight or more and 90 parts by weight or less, and even more preferably 65 parts by weight or more and 85 parts by weight or less, based on 100 parts by weight of the total amount of cellulose acetate impregnated with a plasticizer and water-soluble polymer.

[0038] The water-soluble polymer used in the process of obtaining the dispersion is a polymer in which, when 1 g of polymer is dissolved in 100 g of water at 25°C, the insoluble content is less than 50% by weight. Examples of water-soluble polymers include polyvinyl alcohol, polyethylene glycol, sodium polyacrylate, polyvinylpyrrolidone, polypropylene oxide, polyglycerin, polyethylene oxide, vinyl acetate, modified starch, thermoplastic starch, methylcellulose, ethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose. Among these, polyvinyl alcohol, polyethylene glycol, and thermoplastic starch are preferred, and polyvinyl alcohol and thermoplastic starch are particularly preferred. Thermoplastic starch can be obtained by known methods.

[0039] The mixing of cellulose acetate impregnated with a plasticizer and a water-soluble polymer can be carried out using an extruder such as a twin-screw extruder. The cellulose acetate impregnated with a plasticizer and the water-soluble polymer are mixed at a temperature of 200°C to 280°C. The mixing temperature refers to the cylinder temperature of the extruder. The mixture mixed in the extruder is extruded in a string-like form from a die attached to the tip of the extruder. At this time, the die temperature may be 220°C to 300°C. The string-like extruded mixture is cut and formed into pellets to obtain a dispersion. The obtained dispersion is a dispersion in which the water-soluble polymer is the dispersion medium and the cellulose acetate impregnated with a plasticizer is the dispersed phase.

[0040] (Process to remove water-soluble polymers) The process for removing water-soluble polymers from the obtained dispersion is described below. The method for removing water-soluble polymers is not particularly limited as long as it can dissolve the water-soluble polymers and remove them from the particles. Examples of methods for removing water-soluble polymers include dissolving and removing the water-soluble polymers from the dispersion using a removal solvent such as water, methanol, ethanol, isopropanol, or a mixture thereof. Specifically, for example, a method of removing water-soluble polymers from the dispersion may be used, such as mixing the dispersion with a removal solvent and filtering to obtain the filtrate.

[0041] Regarding the mixing ratio of the dispersion and the removal solvent, it is preferable that the dispersion is 0.01% to 20% by weight relative to the total weight of the dispersion and the removal solvent, more preferably 2% to 15% by weight, and even more preferably 4% to 13% by weight. When the dispersion is 0.01% to 20% by weight relative to the total weight of the dispersion and the removal solvent, the water-soluble polymer is sufficiently dissolved in the solvent and can be thoroughly washed away. Furthermore, the cellulose acetate microparticles that are not dissolved in the removal solvent and the water-soluble polymer that is dissolved in the removal solvent can be easily separated by operations such as filtration or centrifugation.

[0042] The mixing temperature of the dispersion and the removal solvent is preferably 0°C to 200°C, more preferably 20°C to 110°C, and even more preferably 40°C to 80°C. When the mixing temperature of the dispersion and the removal solvent is 0°C to 200°C, the water-soluble polymer dissolves sufficiently in the removal solvent, allowing for thorough washing and removal of the water-soluble polymer. Furthermore, particles can be extracted while maintaining the desired particle shape without deformation or aggregation of the particles.

[0043] The mixing time between the dispersion and the removal solvent is not particularly limited and can be adjusted as appropriate, but may be, for example, 0.5 hours or more, 1 hour or more, 3 hours or more, or 5 hours or more, or 6 hours or less.

[0044] Furthermore, while the method of mixing the dispersion with the removal solvent is not limited as long as it can dissolve the water-soluble polymer, for example, by using a stirring device such as an ultrasonic homogenizer or a three-one motor, the water-soluble polymer can be efficiently removed from the dispersion even at room temperature. For example, when using a three-one motor as the stirring device, the rotation speed during mixing of the dispersion and solvent may be, for example, between 5 rpm and 3000 rpm. This allows for more efficient removal of the water-soluble polymer from the dispersion. It also allows for efficient removal of plasticizers from the dispersion. As a result, microparticles containing cellulose acetate (cellulose acetate microparticles) are obtained.

[0045] Furthermore, in the step of removing the water-soluble polymer from the dispersion, the plasticizer may or may not be removed from the dispersion together with the water-soluble polymer. Therefore, the resulting cellulose acetate microparticles may or may not contain the plasticizer.

[0046] (aqueous component) In the emulsifying formulations of this disclosure, the aqueous component contains one or more aqueous components selected from the group consisting of water and alcohol. In this specification, an aqueous component means water or a component soluble in water. Because the emulsifying formulation contains an aqueous component, the emulsifying formulations of this disclosure exhibit a refreshing feel on the skin.

[0047] The alcohol contained in the aqueous component is not particularly limited, but it is preferable to use one that is highly safe for the human body. For example, the alcohol may be one that can be used as an oral preparation or one that is safe when applied to the skin. The alcohol may be one type or two or more types may be included. The type and amount of alcohol will be selected as appropriate depending on the application or the solubility of the additives.

[0048] Examples of alcohols include ethanol, isopropyl alcohol, and other lower alcohols with 1 to 4 carbon atoms, or polyhydric alcohols. Examples of polyhydric alcohols include propylene glycol, dipropylene glycol, glycerin, diglycerin, low molecular weight (e.g., weight-average molecular weight of 1000 to 20000) polyethylene glycol, 1,3-butylene glycol, or 1,2-pentanediol. Polyhydric alcohols have low volatility and are used as lubricants. Therefore, if the aqueous component contains a polyhydric alcohol, the texture of the emulsifying formulation can be made smoother. The aqueous component may also contain other polyhydric alcohols that are solid at room temperature, such as sorbitol, xylitol, erythritol, mannose, or trehalose. Since such polyhydric alcohols have a sweet taste, they can impart sweetness to the emulsifying formulation.

[0049] The proportion of polyhydric alcohols to the total amount of alcohol is preferably 20% by weight or more, more preferably 50% by weight or more, and even more preferably 100% by weight. When the proportion of polyhydric alcohols to the total amount of alcohol is 20% by weight or more, the texture of the emulsifying formulation can be made smoother.

[0050] When the aqueous component contains water, the water content relative to the total weight of the emulsifying preparation is preferably 10% by weight or less, more preferably 8% by weight or less, and even more preferably 5% by weight or less. If the water content relative to the total weight of the emulsifying preparation is greater than 10% by weight, the water may decompose the biodegradable polymer compounds contained in the cellulose acetate microparticles. In contrast, if the water content relative to the total weight of the emulsifying preparation is 10% by weight or less, water-soluble components such as salt become soluble in the emulsifying preparation, and the effect of water on the biodegradable polymer compounds contained in the cellulose acetate microparticles can be suppressed.

[0051] When the aqueous component contains alcohol, the biodegradable polymer compound contained in the cellulose acetate microparticles can suppress the influence of the aqueous component compared to when the aqueous component is water alone. When the aqueous component contains alcohol, the content of the alcohol-containing aqueous component is preferably 90% by weight or less, more preferably 70% by weight or less, and even more preferably 60% by weight or less, relative to the total weight of the emulsifying formulation.

[0052] (Oily components) In the emulsifying formulations of this disclosure, the term "oil component" refers to a component that is insoluble or sparingly soluble in water. The oil component is an oily useful component that is intended to be incorporated into water-based cosmetics, foods and beverages, or pharmaceutical compositions. The oil component is not particularly limited, but those that are highly safe for the human body are preferred. For example, oil components that can be used as oral formulations or that are safe when applied to the skin may be used. Examples of oil components include fats and oils such as monoglycerides, in which one fatty acid is bonded to glycerin; diglycerides, in which two fatty acids are bonded to glycerin; or triglycerides, in which three fatty acids are bonded to glycerin. Specific examples of fats and oils include vegetable oils such as rapeseed oil, sesame oil, olive oil, coconut oil, camellia oil, corn oil, avocado oil, sasanqua oil, castor oil, jojoba oil, sunflower oil, and soybean oil.

[0053] Other oily components include, for example, esters, silicones, lactones, aldehydes, ketones, higher fatty acids, higher alcohols, essential oils, antioxidants, fat-soluble vitamins, and plant sterols. Examples of esters include monoesters such as cetyl 2-ethylhexanoate, isopropyl myristate, cetyl octanoate, octyl palmitate, isocetyl stearate, isopropyl isostearate, octyl isopalmitate, and isopropyl sebacate; diesters such as diethyl sebacate, diisopropyl sebacate, di-2-ethylhexyl sebacate, and diisopropyl phthalate; and triesters such as glyceryl tri-2-ethylhexanoate and tri(caprylic / capric acid)glycerin. Examples of silicones include straight silicone oils such as dimethyl silicone oil, methylphenyl silicone oil, or methylhydrogen silicone oil, and modified silicone oils in which organic groups are introduced into the side chains or terminals of straight silicone oils. Examples of lactones include gluconolactone, mevalonolactone, lactobionolactone, and pantolactone. Examples of aldehydes include cinnamaldehyde and cinnamic aldehyde. Examples of ketones include α-diketones and other flavorings.

[0054] The oily component may be one type or may contain two or more types. The type and amount of oily component are selected as appropriate according to the application or the solubility of the additive. Furthermore, the oily component should be in an amount of 0.1 to 10 parts by weight per 100 parts by weight of cellulose acetate microparticles. 3 Parts by weight is preferable, preferably 0.5 to 10 2 A weight of approximately 1 to 2 × 10 is more preferable, and even more so 1 to 2 × 10 2 Parts by weight is preferable. The oily component content should be 0.1 to 10 parts by weight of cellulose acetate microparticles. 3 When the amount is in the range of parts by weight, an emulsifying formulation stabilized by cellulose acetate microparticles can be obtained.

[0055] The emulsifying formulations of this disclosure may contain other components, to the extent that they do not impair the effects of this disclosure. For example, the emulsifying formulations may contain surfactants, thickeners, stabilizers, antioxidants, chelating agents, preservatives, pH adjusters, buffers, flavoring agents, sweeteners, and the like.

[0056] Examples of surfactants include fatty acid soaps such as sodium laurate and sodium palmitate, anionic surfactants such as potassium lauryl sulfate and alkyl sulfate triethanolamine ether, cationic surfactants such as stearyltrimethylammonium chloride, benzalkonium chloride, and laurylamine oxide, imidazoline-based amphoteric surfactants such as 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, betaine-based surfactants such as alkyl betaine, amide betaine, and sulfobetaine, amphoteric surfactants such as acylmethyl taurine, sorbitan fatty acid esters such as sorbitan monostearate and sorbitan sesquioleate, glycerin fatty acids such as glyceryl monostearate, and monos Examples include propylene glycol fatty acid esters such as propylene glycol thearate, hydrogenated castor oil derivatives, glycerin alkyl ethers, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, Pluronic® type surfactants, polyoxyethylene / polyoxypropylene alkyl ethers, Tetronic surfactants, polyoxyethylene castor oil / hydrogenated castor oil derivatives, sucrose fatty acid esters, nonionic surfactants such as alkyl glucosides, sodium dodecyl sulfate, vitamin E derivatives, and phospholipids.

[0057] The surfactant is preferably in an amount of 0.01 to 100 parts by weight, more preferably 0.1 to 80 parts by weight, and even more preferably 1 to 50 parts by weight, per 100 parts by weight of the polymer compound (e.g., cellulose acetate) contained in the cellulose acetate microparticles. By having a surfactant amount of 0.01 to 100 parts by weight per 100 parts by weight of the polymer compound contained in the cellulose acetate microparticles, the emulsifying formulation can further improve the dispersibility of oily components.

[0058] Examples of thickening agents include xanthan gum, curdlan, pullulan, guar gum derivatives, locust bean gum, carrageenan, pectin, cellulose derivatives such as hydroxyethylcellulose or carboxymethylcellulose, carbomer (carboxyvinyl polymer), pectin, β-glucan, tamarind gum, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, alginic acid, hyaluronic acid, polyalkylene glycol, etc., or salts thereof. The thickening agent can be used alone or in combination of two or more. Carboxyvinyl polymer is preferred as a thickening agent because it is low-irritant, has a high thickening effect, maintains its viscosity well over time, and is resistant to microbial contamination. By including a thickening agent, the dispersibility of the oily component and cellulose acetate microparticles in the emulsifying formulation can be further stabilized.

[0059] The emulsifying formulation of this disclosure can be prepared, for example, by the method shown below. Cellulose acetate microparticles are stirred with an aqueous component for a predetermined time. This causes the cellulose acetate microparticles to be dispersed and wet by the aqueous component. The wetted cellulose acetate microparticles are then mixed with an oily component for a predetermined time. This causes the oily component and the aqueous component to be emulsified by the cellulose acetate microparticles, thereby obtaining an emulsifying formulation. The emulsifying formulation is not limited to the above preparation method and may be prepared by other known methods.

[0060] The emulsifying formulation of this disclosure is suitable for topical skin preparations. Because the emulsifying formulation of this disclosure has excellent storage stability and a pleasant feel on the skin, it can be used in aqueous cosmetics. Aqueous cosmetics can be prepared, for example, by the method described below. The emulsifying formulation of this disclosure is mixed with, for example, water or other aqueous components, or other additives, and stirred for a predetermined time. This yields an aqueous cosmetic suitable for the intended use.

[0061] The emulsifying formulations of this disclosure can be, for example, sunscreens, makeup bases, foundations, lotions, lipsticks, lip glosses, hair care products, etc. Furthermore, the cellulose acetate microparticles contained in the emulsifying formulations of this disclosure are safe for the human body. For this reason, the emulsifying formulations of this disclosure can be suitably used in food and beverages. The emulsifying formulations of this disclosure can be, for example, creams, sauces, jellies, health foods such as supplements, and other beverages. Furthermore, the emulsifying formulations of this disclosure can be pharmaceuticals (pharmaceutical compositions) such as oral preparations, injections, or topical preparations such as ointments or poultices. [Examples]

[0062] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples, and any modifications or improvements that can achieve the objectives of the present disclosure are included. The microparticles used in Examples 1-2 and Comparative Example 2 were prepared by the methods shown in Manufacturing Examples 1-3 below.

[0063] (Manufacturing Example 1) 100 parts by weight of cellulose diacetate (manufactured by Daicel Corporation: total acetyl substitution degree DS = 2.4) and 25 parts by weight of triacetin as a plasticizer were blended in a dry state, dried at 80°C for 12 hours or more, and then stirred and mixed using a Henschel mixer to obtain a mixture of cellulose acetate and plasticizer. The obtained mixture was fed into a twin-screw extruder (PCM30 manufactured by Ikegai Co., Ltd., cylinder temperature: 200°C, die temperature: 220°C), melt-kneaded, extruded to form pellets, and obtained a kneaded product.

[0064] 32 parts by weight of the resulting compound pellets and 68 parts by weight of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Co., Ltd.: melting point 190°C, degree of saponification 99.1%) as a water-soluble polymer were blended in a dry state, and then supplied to a twin-screw extruder (PCM30 manufactured by Ikegai Co., Ltd., cylinder temperature 220°C, die temperature 220°C) and extruded to form a dispersion.

[0065] The obtained dispersion was mixed with pure water (solvent) to a concentration of 5% by weight or less (weight of dispersion / (weight of dispersion + weight of pure water) × 100), and stirred for 5 hours at 80°C and 500 rpm using a Three One Motor (BL-3000, manufactured by Shinto Kagaku Co., Ltd.). The stirred solution was filtered using filter paper (No. 5A, manufactured by ADVANTEC), and the filtrate was collected. The collected filtrate was again adjusted with pure water to a concentration of 5% by weight or less, and the process of stirring, filtering, and collecting the filtrate was repeated at least three times at 80°C and 500 rpm for 5 hours to obtain cellulose acetate microparticles. The average particle size of the obtained cellulose acetate microparticles was measured by the method described below.

[0066] The average particle size was measured using dynamic light scattering. First, the sample was adjusted to a concentration of approximately 100 ppm using pure water, and then a pure water suspension was prepared using an ultrasonic vibrator. Subsequently, the volume frequency particle size distribution was determined by laser diffraction (using a HORIBA LA-960 laser diffraction / scattering particle size distribution analyzer, with 15 minutes of ultrasonic treatment and a refractive index of 1.500, medium (water; 1.333)), and the average particle size was measured. The average particle size (nm and μm, etc.) referred to here is the particle size value corresponding to 50% of the integrated scattering intensity in the volume frequency particle size distribution. The results for the average particle size of the obtained cellulose acetate microparticles are shown in Table 1.

[0067] (Manufacturing example 2) A kneaded product was obtained in the same manner as in Production Example 1, except that the amount of triacetin was changed to 22 parts by weight. A dispersion was formed in the same manner as in Production Example 1, except that the pellets of the obtained kneaded product were changed to 34 parts by weight and the amount of polyvinyl alcohol to 66 parts by weight. Cellulose acetate microparticles were obtained in the same manner as in Production Example 1, except that the obtained dispersion was mixed with pure water so that it was 5% by weight or less, and vigorously stirred at a temperature of 80°C for 5 hours at a rotation speed of 200 rpm. The results for the average particle size of the obtained cellulose acetate microparticles are shown in Table 1.

[0068] (Manufacturing Example 3) A kneaded product was obtained in the same manner as in Production Example 1, except that triacetin was replaced with acetyltriethyl citrate as a plasticizer. A dispersion was formed in the same manner as in Production Example 1, except that 14 parts by weight of pellets from the obtained kneaded product and 86 parts by weight of polyvinyl alcohol were used. Cellulose acetate microparticles were obtained in the same manner as in Production Example 1, except that the obtained dispersion was mixed with pure water so that it was 5% by weight or less, and the mixture was vigorously stirred at a temperature of 80°C for 3 hours at a rotation speed of 100 rpm. The results for the average particle size of the obtained cellulose acetate microparticles are shown in Table 1.

[0069] (Example 1) As shown in Table 1 below, the following were prepared: 2 parts by weight of cellulose acetate microparticles (average particle size: 5 μm, manufactured by Daicel Corporation) as microparticles; 5 parts by weight of 1,3-butylene glycol (manufactured by Daicel Corporation) and 3 parts by weight of dipropylene glycol (manufactured by Adeka Corporation) as aqueous components; 5 parts by weight of cetyl 2-ethylhexanoate (manufactured by Higher Alcohol Industry Co., Ltd.) as an oily component; 64 parts by weight of pure water, 20 parts by weight of 1% by weight carbomer aqueous solution (AQUPEC 705E, manufactured by Sumitomo Seika Co., Ltd.) and 1 part by weight of 10% by weight potassium hydroxide aqueous solution as solvents.

[0070] The prepared cellulose acetate microparticles and aqueous component were stirred at room temperature for 3 minutes using a Dispermill (manufactured by Primix Corporation), and the resulting mixture was allowed to stand for 10 minutes to wet the cellulose acetate microparticles with the aqueous component. An oily component was added to the wetted mixture and stirred at room temperature for 10 minutes using a Dispermill (manufactured by Primix Corporation) to obtain an emulsifying formulation. Subsequently, a solvent was added to the obtained emulsifying formulation and stirred at room temperature for 10 minutes using a Dispermill (manufactured by Primix Corporation) to obtain an aqueous cosmetic.

[0071] (Example 2, Comparative Examples 1-2) As shown in Table 1 below, an aqueous cosmetic composition was obtained in the same manner as in Example 1, except that the cellulose acetate microparticles were changed. In Example 2, the cellulose acetate microparticles prepared in Production Example 2 were used as the microparticles. In Comparative Example 1, silica particles (Sunsphere L-51, average particle size: 5 μm, manufactured by AGC SI-TEC Inc.) were used as the microparticles. In Comparative Example 2, the cellulose acetate microparticles prepared in Production Example 3 were used as the microparticles.

[0072] (evaluation) The dispersion stability and skin feel of the aqueous cosmetic compositions obtained in Examples 1-2 and Comparative Examples 1-2 were evaluated by the following method.

[0073] <Dispersion Stability Assessment> 20 mL of the obtained aqueous cosmetic was placed in a screw-top bottle and left to stand for 3 months under conditions of 25°C and 75% RH. After that, the uniformity of the aqueous cosmetic was visually observed, and the dispersion stability was evaluated according to the following criteria. Evaluation Criteria Uniform: ○ Uneven: ×

[0074] <Skin feel> Ten monitors each applied 1g of water-based cosmetic to their skin and evaluated whether or not it felt smooth, according to the following criteria. Evaluation Criteria More than 8 people responded that it had a smooth texture: ○ 3-7 people responded that it had a smooth texture: △ Two or fewer people answered that it felt smooth: ×

[0075] The results above are summarized in Table 1 below. [Table 1]

[0076] Furthermore, each aspect disclosed herein may be combined with any other features disclosed herein.

[0077] In summary, the configuration of the present invention and its variations are described below. [1] It comprises one or more aqueous components selected from the group consisting of water and alcohol, an oily component, and microparticles of a polymer compound. The aforementioned microparticles contain cellulose acetate as a polymer compound, The emulsifying formulation wherein the average particle size of the microparticles is 2 to 10 μm. [2] The emulsifying formulation according to [1], wherein the amount of the polymer compound contained in the microparticles is 60% by weight or more, 80% by weight or more, or 95% by weight or more, based on the total weight of the microparticles. [3] The emulsifying formulation according to [1] or [2], wherein the amount of cellulose acetate contained in the polymer compound is 40% by weight or more, 60% by weight or more, or 80% by weight or more, based on the total weight of the polymer compound. [4] Furthermore, it contains polymer compounds other than cellulose acetate (other polymer compounds), The emulsifying formulation according to any one of [1] to [3], wherein the other polymeric compound is at least one selected from the group consisting of polylactic acid, polyglycolic acid, polyaspartic acid, polyvinyl alcohol, polyhydroxyalkanoate, modified polyethylene terephthalate, starch (glucose polymer), cellulose derivatives other than cellulose acetate, polybutylene succinate compounds, polycaprolactone, biodegradable polymeric compounds such as gelatin, pullulan, gellan gum, xanthan gum, tamarind seed gum, locust bean gum, pectin, carrageenan, guar gum, gum arabic, dextran, dextrin, sodium chondroitin sulfate, sodium hyaluronate, sodium alginate, and other polysaccharides, polyvinylpyrrolidone, carboxyvinyl polymer, sodium polyacrylate, methacrylic acid copolymer, and polyethylene glycol. [5] The emulsifying formulation according to any one of [1] to [4], wherein the average particle size of the microparticles is 2 to 10 μm, or its upper limit is 8 μm or 7 μm and its lower limit is 4 μm or 5 μm. [6] The emulsifying preparation according to any one of [1] to [5], wherein the total degree of acetyl substitution of the cellulose acetate is 0.7 or more and 2.9 or less, 1.4 or more and less than 2.6, or 2.0 or more and less than 2.6. [7] The emulsifying formulation according to any one of [1] to [6], wherein the cellulose acetate is cellulose acetate impregnated with a plasticizer. [8] The emulsifying formulation according to [7], wherein the plasticizer is at least one selected from the group consisting of citrate-based plasticizers including citrate esters such as triethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate; glycerin ester-based plasticizers including glycerin alkyl esters such as triacetin, diacetin, and monoacetin; adipic acid-based plasticizers such as diisononyl adipate; and phthalate-based plasticizers such as ethyl phthalate and methyl phthalate. [9] The amount of the plasticizer added is greater than 0 parts by weight and 40 parts by weight or less, 2 parts by weight or more and 40 parts by weight or less, 10 parts by weight or more and 30 parts by weight or less, or 15 parts by weight or more and 20 parts by weight or less, based on 100 parts by weight of the total amount of cellulose acetate and plasticizer, as described in [7] or [8].

[10] The alcohol is an emulsifying preparation according to any one of [1] to [9], which contains a polyhydric alcohol.

[11] The emulsifying formulation according to

[10] , wherein the polyhydric alcohol is at least one selected from the group consisting of propylene glycol, dipropylene glycol, glycerin, diglycerin, low molecular weight (e.g., weight-average molecular weight of 1,000 to 20,000) polyethylene glycol, 1,3-butylene glycol, and 1,2-pentanediol.

[12] The emulsifying preparation according to

[10] or

[11] , wherein the polyhydric alcohol is 20% by weight or more, 50% by weight or more, or 100% by weight, based on the total amount of alcohol.

[13] Furthermore, an emulsifying preparation containing a thickening agent as described in any one of [1] to

[12] .

[14] Furthermore, an emulsifying preparation containing a surfactant, as described in any one of [1] to

[13] .

[15] A water-based cosmetic containing an emulsifying preparation as described in any one of [1] to

[14] .

[16] Food and beverages containing an emulsifying preparation as described in any one of [1] to

[14] .

[17] A pharmaceutical composition comprising an emulsifying preparation described in any one of [1] to

[14] . [Industrial applicability]

[0078] The emulsifying formulation of this disclosure can maintain a stable dispersion of oily components over time using cellulose acetate microparticles that are safe for the human body and the environment, and has a pleasant feel when applied to the skin. For this reason, it can be suitably used in water-based cosmetics. It can also be suitably used in food and beverages, and is particularly suitable for use in health foods. Furthermore, it can be suitably used in pharmaceuticals such as oral preparations, injections, and topical preparations.

Claims

1. It comprises one or more aqueous components selected from the group consisting of water and alcohol, an oily component, and microparticles of a polymer compound. The water-based component contains alcohol, The content of aqueous components, including alcohol, is 70% by weight or less of the total weight of the emulsifying preparation. The aforementioned microparticles contain cellulose acetate as a polymer compound, The average particle size of the aforementioned microparticles is 2 to 10 μm. An emulsifying agent in which the water content relative to the total weight of the emulsifying agent is 10% by weight or less.

2. The emulsifying formulation according to claim 1, wherein the alcohol contains a polyhydric alcohol.

3. The emulsifying formulation according to claim 2, wherein the polyhydric alcohol is 20% by weight or more of the total amount of alcohol.

4. Furthermore, the emulsifying preparation according to any one of claims 1 to 3, further comprising a thickening agent.

5. Furthermore, the emulsifying formulation according to any one of claims 1 to 4, further comprising a surfactant.

6. A water-based cosmetic composition comprising an emulsifying preparation according to any one of claims 1 to 5.

7. Food and beverages comprising an emulsifying preparation according to any one of claims 1 to 5.

8. A pharmaceutical composition comprising an emulsifying preparation according to any one of claims 1 to 5.

Images