Topical skin preparation

Abstract

To provide a topical skin preparation that offers a superior user experience while containing niacinamide.SOLUTION: A topical skin preparation contains (A) niacinamide, (B) at least one selected from tranexamic acid and D-pantothenyl alcohol, and at least two selected from (C) polyhydric alcohols, (D) thickeners, and (E) oil solutions.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an external skin preparation containing niacinamide, at least one member selected from tranexamic acid and D-pantothenyl alcohol, and at least two members selected from a polyhydric alcohol, a thickener, and an oil. [Background technology]

[0002] Niacinamide has whitening, anti-wrinkle, and anti-aging effects, and therefore various topical skin preparations containing niacinamide have been proposed (Patent Document 1). In order to enjoy the effects of niacinamide, its incorporation into cosmetics such as sunscreen cosmetics and all-in-one gels has been considered, but such topical skin preparations have problems with the feel of use, such as the generation of squeaking sensation after application and low moisturizing feeling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-063061 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, the present inventors conducted various investigations with the objective of providing an external skin preparation that contains niacinamide and yet has an excellent feel when used. [Means for solving the problem]

[0005] As a result, the inventors have succeeded in developing an external skin preparation that has an excellent feel when used by comprising niacinamide together with at least one selected from tranexamic acid and D-pantothenyl alcohol, and at least two selected from polyhydric alcohols, thickeners, and oils, thereby completing the present invention.

[0006] That is, the present invention is as follows.

[0007] <1> (A) Niacinamide, (B) at least one selected from tranexamic acid and D-pantothenyl alcohol, and, (C) at least two selected from a polyhydric alcohol, (D) a thickener, and (E) an oil; A skin topical preparation comprising: <2> (A) Niacinamide, (B) at least one selected from tranexamic acid and D-pantothenyl alcohol, (C) polyhydric alcohol, (D) a thickening agent, And, (E) oil solution, A skin topical preparation comprising: <3> The composition further comprises (F) dipotassium glycyrrhizinate. <1> or <2> 13. The skin topical preparation according to any one of claims 1 to 12. <4> Further, the composition further comprises (G) an ultraviolet protection agent. <1> or <2> 13. The skin topical preparation according to any one of claims 1 to 12. <5> The content of (A) is 5% by mass or more. <1> or <2> 13. The skin topical preparation according to any one of claims 1 to 12. <6> The content of (B) is 0.1 mass% or more. <1> or <2> 13. The skin topical preparation according to any one of claims 1 to 12. <7> Characterized by a viscosity of 5,000 mPa·s or more <1> or <2> 13. The skin topical preparation according to any one of claims 1 to 12. <8> It is characterized as being oil-in-water <1> or <2> 13. The skin topical preparation according to any one of claims 1 to 12. <9> It is characterized by being used for sunscreen <4> 2. The topical skin preparation according to claim 1 . Effect of the Invention

[0008] According to the present invention, by containing niacinamide together with at least one selected from tranexamic acid and D-pantothenyl alcohol, and at least two selected from polyhydric alcohols, thickeners, and oils, it is possible to provide an external skin preparation that has an excellent feel when applied, such as good spreadability, no squeaking, and a moist feel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The skin topical preparation of the present invention will be described in detail below. Note that the present invention is not limited to the following embodiments, and may be modified within the scope of what a person skilled in the art can imagine, such as other embodiments, additions, modifications, deletions, etc., and any embodiment is within the scope of the present invention as long as it exhibits the functions and effects of the present invention.

[0010] <(A) Niacinamide> The skin external preparation of the present invention is characterized by containing niacinamide. Niacinamide is an amide of niacin (nicotinic acid / vitamin B3), a water-soluble vitamin that is a type of vitamin B group. In the present invention, niacinamide that is usually used in cosmetics and quasi-drugs can be used, and for example, niacinamide extracted from natural products, purified from them, synthesized by known methods, etc., can also be used as a commercially available product.

[0011] In the skin topical preparation of the present invention, the content of niacinamide is not particularly limited, and is preferably 1% by mass or more, more preferably 3% by mass or more, and is particularly preferably 5% by mass or more from the viewpoint of excellent usability and the ability to enjoy the effects of niacinamide. The upper limit is not particularly limited, but is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less. The content of niacinamide in the skin topical preparation of the present invention can be analyzed, for example, by liquid chromatography, and the conditions can be quantified in accordance with the quantification method of nicotinamide described in the Quasi-Drug Raw Materials Standards 2021, for example.

[0012] <(B) Tranexamic acid, D-pantothenyl alcohol> The skin external preparation of the present invention is characterized by containing at least one component selected from tranexamic acid and D-pantothenyl alcohol. Each component will be described below.

[0013] (Tranexamic acid) Tranexamic acid is a type of artificially synthesized amino acid, and is used as a hemostatic agent, an anti-inflammatory agent, etc. In the present invention, the tranexamic acid that can be used is one that is usually used in cosmetics, quasi-drugs, etc.

[0014] In the skin external preparation of the present invention, the content of tranexamic acid is not particularly limited, and for example, it is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and from the viewpoint of excellent usability and enjoying the effect of tranexamic acid, it is particularly preferably 1% by mass or more. There is no particular limit to the upper limit, but it is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less. The content of tranexamic acid in the skin external preparation of the present invention can be analyzed, for example, by high performance liquid chromatography, and the conditions thereof can be, for example, quantified according to the quantification method of tranexamic acid described in the 18th revised Japanese Pharmacopoeia.

[0015] (D-Pantothenyl Alcohol) D-pantothenyl alcohol, also called panthenol, is a derivative of vitamin B5 (pantothenic acid) and is a water-soluble vitamin that is a type of vitamin B. In the present invention, D-pantothenyl alcohol that is usually used in cosmetics and quasi-drugs can be used, and for example, commercially available products such as those extracted from natural products, those purified from natural products, and those synthesized by known methods can also be used.

[0016] In the skin topical preparation of the present invention, the content of D-pantothenyl alcohol is not particularly limited, and is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and is particularly preferably 0.1% by mass or more from the viewpoint of excellent usability and the ability to enjoy the effects of D-pantothenyl alcohol. The upper limit is not particularly limited, but is preferably 5% by mass or less, more preferably 3% by mass or less, and particularly preferably 1% by mass or less. The content of niacinamide in the skin topical preparation of the present invention can be analyzed, for example, by high performance liquid chromatography, and the conditions can be quantified in accordance with the quantitative method of D-pantothenyl alcohol described in, for example, the Quasi-Drug Raw Materials Standards 2021.

[0017] In the skin external preparation of the present invention, the blending ratio of (A) niacinamide and (B) tranexamic acid or D-pantothenyl alcohol is not particularly limited, but is preferably (A):(B)=1:0.001-30 by mass ratio, more preferably 1:0.005-20, and particularly preferably 1:0.01-10. In particular, when (B) is tranexamic acid, the blending ratio with (A) niacinamide is preferably (A):(B)=1:0.01-30 by mass ratio, more preferably 1:0.05-20, and particularly preferably 1:0.1-10. In addition, when (B) is D-pantothenyl alcohol, the blending ratio with (A) niacinamide is preferably (A):(B)=1:0.001-10 by mass ratio, more preferably 1:0.005-5, and particularly preferably 1:0.01-1.

[0018] <(C) polyhydric alcohol, (D) thickener, (E) oil> The skin external preparation of the present invention is characterized by containing at least two selected from (C) polyhydric alcohol, (D) thickener, and (E) oil. Here, the at least two selected from (C) polyhydric alcohol, (D) thickener, and (E) oil may be two or more (C), two or more (D), or two or more (E), but it is preferable to blend one or more components each from (C) and (D), one or more components each from (D) and (E), or one or more components each from (C) and (E), and it is particularly preferable to blend one or more components each from (C), (D), and (E). Components other than (C), (D), and (E) are described in detail below.

[0019] [(C) Polyhydric alcohol] In the present invention, the polyhydric alcohol refers to an alcohol having a valence of 2 to 3. The polyhydric alcohol in the present invention is not particularly limited as long as it is one that is usually used in external skin preparations, but for example, a dihydric or trihydric alcohol having 2 to 20 carbon atoms is preferable, a dihydric or trihydric alcohol having 2 to 16 carbon atoms is more preferable, and a dihydric or trihydric alcohol having 2 to 10 carbon atoms is particularly preferable. Specific examples of such polyhydric alcohols include ethylene glycol, propylene glycol (PG), 1,3-butylene glycol (BG), diethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-pentanediol (pentylene glycol), 1,5-pentanediol, 1,2-hexanediol, 1,2-octanediol, caprylyl glycol, decylene glycol, glycerin, polyethylene glycol, and the like. In the present invention, propylene glycol (PG), 1,3-butylene glycol (BG), dipropylene glycol, 1,2-pentanediol (pentylene glycol), 1,5-pentanediol, 1,2-hexanediol, 1,2-octanediol, glycerin, and polyethylene glycol are preferred, and propylene glycol (PG), 1,3-butylene glycol (BG), 1,2-pentanediol (pentylene glycol), 1,2-hexanediol, and glycerin are particularly preferred.

[0020] When polyhydric alcohol is blended in the skin external preparation of the present invention, its content is not particularly limited, and for example, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and from the viewpoint of obtaining a skin external preparation with excellent usability, it is particularly preferably 1% by mass or more. Also, it is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 35% by mass or less. In addition, when two or more kinds of polyhydric alcohol are blended, it is the total amount.

[0021] [(D) Thickener] The thickener that can be used in the topical skin preparation of the present invention is not particularly limited as long as it is a water-soluble component that can be used in cosmetics, topical medicines, quasi-drugs, etc., and synthetic polymers, semi-synthetic polymers, natural polymers, clay minerals, etc. can be used.

[0022] Synthetic polymers include hydrophilic synthetic polymers such as carboxyvinyl polymers, polyvinyl alcohol, acrylic acid / alkyl methacrylate copolymers, acrylates / alkyl acrylate crosspolymers, polyacrylic acid, polyacrylamide, polyalkylacrylamide / polyacrylamide copolymers, carboxymethyl cellulose, and cationic cellulose.

[0023] Examples of the semi-synthetic polymer include cellulose derivatives such as carboxymethylcellulose or salts thereof, methylcellulose, ethylcellulose, propylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, sulfonated cellulose derivatives, etc. Other semi-synthetic polymers include propylene glycol alginate, ethylene glycol alginate, dextrin fatty acid ester, gelatin fatty acid ester, gelatin fatty acid amide, etc.

[0024] Examples of natural polymers include polysaccharides and derivatives thereof, such as xanthan gum, succinoglycan, carrageenan, guar gum, locust bean gum, celluloses, galactan, gum arabic, tragacanth gum, tamarind gum, agar, agarose, mannan, curdlan, alginic acid or salts thereof, gum arabic, pectin, quince seed, starch, algae colloid, casein, collagen, gelatin, albumin, fibroin, elastin, keratin, and water-soluble proteins such as sericin.

[0025] Examples of clay minerals include laponite, bentonite, smectite kaolinite, and montmorillonite.

[0026] When the skin external preparation of the present invention contains a thickener, its content is not particularly limited, and is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and from the viewpoint of obtaining a skin external preparation with excellent usability, is particularly preferably 0.1% by mass or more. Also, it is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less. In addition, when two or more types of thickeners are contained, it is the total amount.

[0027] [(E) Oil] The oil agent usable in the present invention is not particularly limited as long as it is one that is usually used in skin external preparations, but it is preferably an oil agent that is liquid at 25°C, and is particularly preferably non-volatile.Specific examples of the oil agent include hydrocarbon oils such as liquid paraffin, squalane, and squalene; fatty acids such as isostearic acid, oleic acid, and polyhydroxystearic acid; higher alcohols such as octyldodecanol and tetradecyldecanol; isopropyl palmitate, isopropyl myristate, isopropyl stearate, isobutyl stearate, 2-ethylhexyl stearate, isopropyl isostearate, butyl isostearate, decyl isostearate, lauryl isostearate, isodecyl isodecanoate, isodecyl isononanoate, isotridecyl isononanoate, isononyl isononanoate, diisostearyl malate, neopentyl glycol dioctanoate, propylene glycol dicaprate, propylene glycol dicaprylate, glyceryl tri-2-ethylhexanoate, monoisopropyl glyceryl tri-2-ethylhexanoate, glyceryl monoisopropyl glyceryl tri-2-ethylhexanoate, ... Examples of the oils include ester oils such as polyglyceryl isostearate, polyglyceryl diisostearate, diglyceryl triisostearate, diglyceryl tetraisostearate, diethyl sebacate, cetyl 2-ethylhexanoate, ethylhexyl palmitate, octyldodecyl myristate, oleyl oleate, ethyl oleate, di(phytosteryl / 2-octyldodecyl) N-lauroyl-glutamate, di(phytosteryl / behenyl / 2-octyldodecyl) N-lauroyl-glutamate, di(cholesteryl / 2-octyldodecyl) N-lauroyl-glutamate, and isopropyl N-lauroyl sarcosine; and silicone oils such as dimethylpolysiloxane, cyclopentasiloxane, and alkoxy-modified polysiloxane. One or more of these oils may be used.

[0028] When an oil agent is blended in the skin external preparation of the present invention, its content is not particularly limited, and for example, it is preferably 0.1% by mass or more, more preferably 1% by mass or more, and from the viewpoint of obtaining a skin external preparation with excellent usability, it is particularly preferably 3% by mass or more. Also, it is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less. In addition, when two or more kinds of oil agents are blended, it is the total amount.

[0029] <(F) Dipotassium glycyrrhizinate> The skin external preparation of the present invention preferably contains dipotassium glycyrrhizinate. Dipotassium glycyrrhizinate is a salt of glycyrrhizic acid and potassium, also called dipotassium glycyrrhizinate, dipotassium glycyrrhizinate, glycyrrhizic acid K2, or glycinone K2, and is a component known to be contained in liquorice (licorice) and has an anti-inflammatory effect. In the present invention, dipotassium glycyrrhizinate that is usually used in cosmetics and quasi-drugs can be used, and for example, commercially available products such as those extracted from natural products, those purified from them, and those synthesized by known methods can also be used.

[0030] The content of dipotassium glycyrrhizinate in the skin topical preparation of the present invention is not particularly limited, and is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and from the viewpoint of obtaining a skin topical preparation with excellent usability, is particularly preferably 0.05% by mass or more. Also, it is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 1% by mass or less. The content of dipotassium glycyrrhizinate in the skin topical preparation of the present invention can be analyzed, for example, by high performance liquid chromatography, and the conditions thereof can be quantified, for example, in accordance with the quantification method of dipotassium glycyrrhizinate described in the Quasi-Drug Raw Materials Standards 2021.

[0031] <(G) UV protection agent> The skin external preparation of the present invention is characterized in that it contains an ultraviolet protection agent as one of its preferred forms. The ultraviolet protection agent that can be used in the present invention is not particularly limited as long as it is one that is usually used in skin external preparations, and for example, an ultraviolet scattering agent or an ultraviolet absorbing agent can be used.

[0032] As the ultraviolet scattering agent, inorganic compounds are preferred, and metal oxides are more preferred, because they have a high ultraviolet scattering effect.Specific examples include one or more selected from titanium oxide, zinc oxide, iron oxide, zirconium oxide, and cerium oxide.Among these, it is preferred to use one or more selected from titanium oxide and zinc oxide.

[0033] In addition, the ultraviolet scattering agent used in the present invention is preferably one that has been subjected to hydrophobic treatment. By hydrophobizing the surface, dispersibility in oil and water resistance can be improved. The hydrophobic treatment of the ultraviolet scattering agent may be performed using a known surface treatment agent that is hydrophobic, and examples of such treatment include silicone treatment such as methylhydrogenpolysiloxane, methylpolysiloxane, etc.; alkylsilane treatment; fluorine treatment using perfluoroalkyl phosphate ester, perfluoroalcohol, etc.; amino acid treatment using N-acylglutamic acid, etc.; lecithin treatment; metal soap treatment; fatty acid treatment; alkyl phosphate ester treatment, etc.

[0034] The ultraviolet scattering agent used in the present invention has an average particle size of preferably 1 to 1000 nm, more preferably 5 to 500 nm, and particularly preferably 10 to 300 nm, from the viewpoint of obtaining an external skin preparation excellent in usability and sunscreen effect. The average particle size of the ultraviolet scattering agent used in the present invention is measured by a dynamic light scattering method.

[0035] Examples of ultraviolet absorbers include ethylhexyl methoxycinnamate, octocrylene, dimethicodethyl benzalmalonate, polysilicon-15, t-butyl methoxydibenzoylmethane, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bisethylhexyloxyphenol methoxyphenyl triazine, oxybenzone-3, methylene bisbenzotriazolyl tetramethylbutylphenol, phenylbenzimidazole sulfonic acid, homosalate, ethylhexyl salicylate, etc. Among these, it is preferable to use one or more selected from ethylhexyl methoxycinnamate, diethylamino hydroxybenzoyl hexyl benzoate, and bisethylhexyloxyphenol methoxyphenyl triazine.

[0036] The content of the UV protection agent in the skin external preparation of the present invention is not particularly limited, and is preferably 1 mass% or more, more preferably 3 mass% or more, and from the viewpoint of obtaining a skin external preparation with excellent usability and sunscreen effect, is particularly preferably 5 mass% or more. Also, it is preferably 50 mass% or less, more preferably 40 mass% or less, and particularly preferably 30 mass% or less. When two or more UV protection agents are used, it is the total amount.

[0037] The content of the ultraviolet scattering agent in the skin external preparation of the present invention is not particularly limited, and is preferably 1 mass% or more, more preferably 3 mass% or more, and from the viewpoint of obtaining a skin external preparation with excellent usability and sunscreen effect, is particularly preferably 5 mass% or more. Also, it is preferably 40 mass% or less, more preferably 30 mass% or less, and particularly preferably 25 mass% or less. When two or more ultraviolet scattering agents are used, it is the total amount.

[0038] <Other ingredients> In addition to the above-mentioned components, the skin external preparation of the present invention can contain other components as necessary.These other components include, for example, alcohols other than polyhydric alcohols such as lower alcohols, higher alcohols, and sugar alcohols, preservatives, fragrances, surfactants, film-forming agents, pH adjusters, deodorants, chelating agents, antioxidants, antibacterial agents, antibacterial and antifungal agents, anti-inflammatory agents, and skin-whitening agents, as well as beauty and medicinal ingredients such as animal extracts, plant extracts, niacinamide, and vitamins other than D-pantothenyl alcohol, and one or more of the components usually used in skin external preparations.

[0039] <External skin preparations> The skin topical preparation of the present invention is a composition that is applied to the skin. The skin topical preparation of the present invention preferably has a high viscosity, preferably 3,000 mPa·s or more, more preferably 5,000 mPa·s or more, and from the viewpoint of excellent usability, particularly preferably 8,000 mPa·s or more. The viscosity of the skin topical preparation of the present invention can be measured, for example, with a B-type viscometer (Brookfield rotational viscometer, temperature: 25°C, rotation speed: 5 rpm).

[0040] The pH of the topical skin preparation of the present invention is preferably 4 to 8, and from the viewpoint of excellent usability, more preferably 5 to 7. The pH of the topical skin preparation of the present invention can be measured, for example, by the glass electrode method using a pH meter.

[0041] The topical skin preparation of the present invention can be used in medicines, quasi-drugs, and cosmetics, for example, in skin care cosmetics such as lotions, milky lotions, creams, gels, and serums, and makeup cosmetics such as makeup bases, sunscreens, and foundations.

[0042] The skin topical preparation of the present invention can be produced according to a conventional method. For example, when an oil-in-water composition is to be obtained, an aqueous phase is prepared by uniformly dispersing (A) niacinamide, (B) tranexamic acid and / or D-pantothenyl alcohol, (C) polyhydric alcohol, (D) thickener, and optionally an emulsifier in water, and an oil phase containing (E) oil agent homogenized in advance is added, and homogenized with a homomixer or the like, and the pH is adjusted as necessary to obtain the skin topical preparation of the present invention. When (F) dipotassium glycyrrhizinate is to be blended, it is added during the preparation of the aqueous phase, and the oil phase is added and homogenized to obtain the skin topical preparation. When (G) an ultraviolet protection agent is to be blended, it is dispersed in the oil phase in advance, homogenized, and emulsified with the aqueous phase to obtain the skin topical preparation. It can be produced by the above. EXAMPLES

[0043] The present invention will be described below based on examples, but the present invention is not limited to these examples and can take various forms. The amount of each component used in the examples is in mass % unless otherwise specified.

[0044] [Evaluation of topical skin preparations (1) Oil-in-water type topical skin preparations for sunscreen] <Preparation of topical skin preparation> According to Table 1, the oil-in-water type external sunscreen skin preparations of Comparative Examples 1 to 3 and Examples 1 to 7 were prepared by the following method. Specifically, an oil phase in which (G) was uniformly dispersed in (E) was added to an aqueous phase in which (A), (B), (C), and (D), polysorbate 20, and PEG-60 hydrogenated castor oil were uniformly dissolved in water, and the oil phase was emulsified uniformly using a homomixer or the like, the pH was adjusted using sodium citrate, and phenoxyethanol was added to prepare the emulsion. When (F) was to be added, it was added to the aqueous phase together with (A) to (D) and uniformly dissolved.

[0045] [Table 1]

[0046] <Storage stability evaluation > (1) Viscosity measurement The viscosity of the obtained sunscreen skin topical preparation was measured immediately after production and after storage at 50°C for 7 days using a B-type viscometer (Brookfield RVT model, temperature: 25°C, rotation speed: 5 rpm). The viscosity decay rate was calculated based on the following formula. A smaller decay rate indicates better storage stability. [Formula] Decay rate (%) = (viscosity immediately after manufacture - viscosity after storage at 50°C for 7 days) / (viscosity immediately after manufacture) (Viscosity decay rate) Less than 20%: Excellent storage stability 20% to less than 40%: Excellent storage stability Over 40%: Poor storage stability, not suitable for commercialization The results are shown in Table 2.

[0047] (2)pH measurement The pH of the obtained skin sunscreen preparation was measured immediately after production and after storage at 50° C. for 7 days using a pH meter (Horiba, Ltd. pH meter F71 type). The results are shown in Table 2.

[0048] (3) Changes in appearance The appearance of the obtained skin sunscreen topical preparations was visually inspected after storage at 50°C for 7 days after production. Those that showed no discoloration compared to immediately after production were rated as ◯, and those that showed obvious discoloration compared to immediately after production were rated as ×. The results are shown in Table 2.

[0049] <Evaluation of Usability> The feel of the obtained sunscreen skin topical preparation was evaluated. Five subjects in their 20s and 30s were randomly selected as subjects. The skin topical preparation was applied to the face of each subject, and the subject was asked to make a comprehensive judgment based on the feel of the preparation (ease of spreading when applied, lack of squeaking after application) as evaluation items, and to complete a questionnaire based on a five-point rating scale. The average value of each item in the questionnaire was calculated and evaluated. (Easy spread when applied) 5: Very good (grows smoothly) 4: Good (good stretch) 3: Neither (stretches to a degree that is not noticeable when in use) 2: Bad (Poor stretchiness, bothersome when using) 1: Very bad (poor stretch, not suitable for use) (No squeaking after application) 5: Very good (no squeaky feeling after application, very moisturizing) 4: Good (no squeaking after application and moisturizing) 3: Neither (a slight squeaking sensation is felt after application, but it is not noticeable during use) 2: Bad (Feels squeaky after application) 1: Very bad (squeaky feeling after application, not suitable for use) The results are shown in Table 2.

[0050] [Table 2]

[0051] The composition of the present invention had a viscosity of 1,800 to 20,000 mPa·s and a pH of 6.1 to 6.4 at the time of production. After storage at 50°C for 7 days, the viscosity attenuation rate was less than 40% in Comparative Examples 1 to 3, the pH fluctuation was 0.3 to 0.4, and discoloration was observed in Comparative Example 2. On the other hand, the viscosity attenuation rate of Examples 1 to 7 was less than 40%, the pH fluctuation was 0 to 0.2, which was smaller than the comparative examples, and no discoloration occurred, so all of them showed higher storage stability than Comparative Examples 1 to 3. In particular, Examples 3 to 7, which have a viscosity of 5,000 mPa·s or more, had a very small viscosity attenuation rate of 11% or less, and were topical skin preparations with excellent storage stability compared to Comparative Examples 1 to 3. In addition, the topical skin preparations of Comparative Examples 1 to 3 were prone to feel squeaky after application, but the topical skin preparations of Examples 1 to 7 of the present invention all spread well when applied, were moist with almost no squeaky feeling after application, and had an excellent feel in use. In particular, Examples 3 to 7, which had a viscosity of 5,000 mPa·s or more, spread well when applied compared to not only Comparative Examples 1 to 3 but also Examples 1 and 2, were moisturized without any squeaking after application, and had an excellent feel when used.

[0052] [Evaluation of topical skin preparations (2) Oil-in-water type gel-type topical skin preparations] <Preparation of topical skin preparation> According to Table 3, the oil-in-water type gel-type skin preparations for external use of Comparative Examples 4 to 6 and Examples 8 to 14 were prepared by the following method. Specifically, the oil phase in which (E) was uniformly dispersed was added to the aqueous phase in which (A), (B), (C), and (D), polysorbate 60, and glyceryl stearate were uniformly dissolved in water, and the mixture was emulsified uniformly using a homomixer or the like, the pH was adjusted using sodium hydroxide, and phenoxyethanol was added to prepare the mixture. When (F) was to be blended, it was added to the aqueous phase together with (A) to (D) and uniformly dissolved.

[0053] <Physical property measurements> (1) Viscosity measurement The viscosity of the obtained gel-type skin preparation for external use was measured using a Brookfield viscometer (RVT model, temperature: 25° C., rotation speed: 5 rpm). The results are shown in Table 3.

[0054] (2)pH measurement The pH of the obtained gel-type skin preparation for external use was measured using a pH meter (pH meter F71 model, manufactured by Horiba, Ltd.) The results are shown in Table 3.

[0055] <Evaluation of Usability> The obtained gel-type skin preparation for external use was evaluated for usability. Five subjects in their 20s and 30s were randomly selected as subjects. The skin preparation for external use was applied to the face of each subject, and the subject was comprehensively judged for usability (ease of spreading when applied, moist feeling) as evaluation items, and a questionnaire was administered based on a 5-point evaluation scale. The average value of each item in the questionnaire was calculated and evaluated. (Good spreadability when applied) 5: Very good (smooth and stretchy) 4: Good (good stretch) 3: Neither (stretches to a degree that is not noticeable when in use) 2: Bad (Poor stretchiness, bothersome when using) 1: Very poor (very poor stretch, not suitable for use) (Moisturizing feeling after application) 5: Very good (very moisturizing after application) 4: Good (moisturizes after application) 3: Neither (Feels slightly moist after application) 2: Poor (hardly any moist feeling after application) 1: Very bad (no moist feeling after application, not suitable for use)

[0056] [Table 3]

[0057] The compositions of the present invention had a viscosity of 1,680-9,400 mPa·s and a pH of 6-6.6 at the time of production. The skin topical preparations of Comparative Examples 4-6 did not feel moist after application, but the skin topical preparations of Examples 8-14 of the present invention all spread well when applied, were moist after application, and had an excellent feel when used. In particular, Examples 10-14, which have a viscosity of 5,000 mPa·s or more, spread well when applied, were moist after application, and had an excellent feel when used, compared to not only Comparative Examples 4-6 but also Examples 8 and 9.

[0058] <Preparation of topical skin preparation> The oil-in-water type topical skin sunscreen preparations shown in Tables 4 to 6 were prepared in the same manner as in Example 1. The obtained topical skin preparations all had a viscosity of 5,000 mPa s or more, a pH of 5 to 8, spread easily when applied, were moisturized without any squeaking after application, and had excellent usability as well as excellent sunscreen effects.

[0059] [Table 4]

[0060] [Table 5]

[0061] [Table 6]

[0062] <Preparation of topical skin preparation> The oil-in-water type gel-type topical skin preparations shown in Tables 7 to 10 were prepared in the same manner as in the Examples. All of the obtained topical skin preparations had a viscosity of 5,000 mPa s or more, a pH of 5 to 8, good spreadability upon application, and a moist feeling even after application, providing an excellent feel when used.

[0063] [Table 7]

[0064] [Table 8]

[0065] [Table 9]

[0066] [Table 10] [Industrial Applicability]

[0067] The topical skin preparation of the present invention contains niacinamide, at least one selected from tranexamic acid and D-pantothenyl alcohol, and at least two selected from (C) a polyhydric alcohol, (D) a thickener, and (E) an oil, thereby providing a topical skin preparation that has excellent usability and has high industrial applicability.

Claims

1. (A) niacinamide, (B) at least one selected from tranexamic acid and D-pantothenyl alcohol, and, (C) at least two selected from a polyhydric alcohol, (D) a thickener, and (E) an oil; A skin topical preparation comprising:

2. The skin topical preparation according to claim 1, further comprising (F) dipotassium glycyrrhizinate.

3. The skin external preparation according to claim 1 , further comprising (G) an ultraviolet protection agent.

4. 2. The skin topical preparation according to claim 1, characterized in that the content of (A) is 5% by mass or more.

5. 2. The skin topical preparation according to claim 1, characterized in that the viscosity is 5,000 mPa·s or more.

6. 2. The skin topical preparation according to claim 1, which is an oil-in-water type.

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