Topical preparation for skin

Abstract

To provide a topical preparation for skin enabling superior usability and stability even when containing an ultraviolet scattering agent.SOLUTION: A topical preparation for skin characterized by comprising (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an external skin preparation containing (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin. The present invention also relates to an external skin preparation containing (A) an ultraviolet scattering agent, (B) carrageenan, (C) pectin, and further (D) xanthan gum. [Background technology]

[0002] Ultraviolet rays are known to cause various phenomena, such as skin inflammation and aging, and sunscreen cosmetics are used to alleviate skin inflammation. Sunscreen cosmetics contain ingredients with UV protection, such as UV scattering agents and UV absorbers. However, UV scattering agents, for example, can cause stickiness and unevenness upon application, resulting in a poor usability (Patent Document 1). Sunscreen cosmetics containing UV protection ingredients also contain various other ingredients, but still suffer from a poor usability. Furthermore, the stability of UV protection ingredients and sunscreen cosmetics is poor, resulting in, for example, the tendency for ingredients to aggregate when stored for long periods of time. This not only results in a poor appearance of the sunscreen cosmetics, but also in the inability to fully demonstrate the effects of the UV protection ingredients and sunscreen cosmetics (Patent Documents 1 and 2). Even when water-soluble thickeners are added to improve usability and stability, satisfactory usability and stability have yet to be achieved. Therefore, there is a demand for sunscreen cosmetics with excellent usability and stability. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-172634 [Patent Document 2] Japanese Patent Publication No. 2022-153341 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, the present inventors have conducted various studies to provide an external skin preparation that contains an ultraviolet scattering agent and yet has excellent usability and stability. [Means for solving the problem]

[0005] As a result, the present inventors have succeeded in developing an external skin preparation containing (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin, which has excellent usability and stability, and have completed the present invention. Furthermore, the present inventors have succeeded in developing an external skin preparation containing (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin, as well as (D) xanthan gum, which has even more excellent usability and stability, and have completed the present invention.

[0006] That is, the present invention is as follows. <1> A topical skin preparation containing (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin. <2> Furthermore, (D) xanthan gum is contained <1> The topical skin preparation according to claim 1. <3> (A) is at least one selected from titanium oxide and zinc oxide <1> The topical skin preparation according to claim 1. <4> The content of (B) in 100 parts by mass of the topical skin preparation is 0.01 to 1 part by mass. <1> The topical skin preparation according to claim 1. <5> When the content of (A) in the topical skin preparation is taken as 1, the ratio of (A):(B) is 1:0.0005-3. <1> The topical skin preparation according to claim 1. <6> The content of (C) in 100 parts by mass of the topical skin preparation is 0.05 to 3 parts by mass. <1> The topical skin preparation according to claim 1. <7> When the content of (A) in the topical skin preparation is taken as 1, the ratio of (A):(C) is 1:0.005-3. <1> The topical skin preparation according to claim 1. <8> The content of (D) in 100 parts by mass of the topical skin preparation is 0.05 to 3 parts by mass. <2> The topical skin preparation according to claim 1. <9> When the content of (A) in the topical skin preparation is taken as 1, the ratio of (A):(D) is 1:0.005-3. <2> The topical skin preparation according to claim 1. <10> If the content of (A) in the topical skin preparation is 1, the ratio of (A):(B):(C) is 1:0.0005-3:0.005-3. <1> The topical skin preparation according to claim 1. <11> If the content of (A) in the topical skin preparation is 1, the ratio of (A):(B):(C):(D) is 1:0.0005-3:0.005-3:0.005-3. <2> The topical skin preparation according to claim 1. <12> It is a sunscreen cosmetic <1> The topical skin preparation according to claim 1.

[0007] According to the present invention, an external skin preparation having excellent usability and stability can be provided by containing (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin. Furthermore, an external skin preparation having even better usability and stability can be provided by containing (D) xanthan gum in addition to (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin. DETAILED DESCRIPTION OF THE INVENTION

[0008] The topical skin 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, added, modified, deleted, or otherwise altered within the scope of what one skilled in the art can conceive. Any embodiment is within the scope of the present invention as long as it exhibits the functions and effects of the present invention.

[0009] <(A) UV scattering agent> The topical skin preparation of the present invention contains an ultraviolet scattering agent. The ultraviolet scattering agent that can be used in the present invention is not particularly limited as long as it is one that is normally used in topical skin preparations, but inorganic compounds are preferred, and metal oxides are more preferred, because of their high ultraviolet scattering effect. Specifically, one or more selected from titanium oxide, zinc oxide, iron oxide, zirconium oxide, cerium oxide, silicic anhydride, and talc can be used. Among these, titanium oxide and zinc oxide are preferred.

[0010] The ultraviolet scattering agent used in the present invention may have an untreated surface, or may have been subjected to a surface treatment such as hydrophobization or hydrophilization. The hydrophobization treatment of the ultraviolet scattering agent may be carried out using a known hydrophobizing surface treatment agent, such as silicone treatment with methylhydrogenpolysiloxane or methylpolysiloxane; alkylsilane treatment; fluorine treatment with perfluoroalkyl phosphate ester or perfluoroalcohol; amino acid treatment with N-acylglutamic acid or the like; lecithin treatment; metal soap treatment; fatty acid treatment; alkyl phosphate ester treatment, etc. The hydrophilization treatment of the ultraviolet scattering agent may be carried out using a known hydrophilizing surface treatment agent, such as treatment with silica, titanium oxide, zinc oxide, zirconium oxide, cerium oxide, or aluminum hydroxide.

[0011] The ultraviolet scattering agent used in the present invention preferably has an average primary particle size of 0.5 to 1000 nm, more preferably 1 to 500 nm, and particularly preferably 5 to 40 nm from the viewpoint of obtaining an external skin preparation with excellent usability and stability. The average primary particle size of the ultraviolet scattering agent used in the present invention can be measured, for example, by dynamic light scattering.

[0012] The content of (A) ultraviolet scattering agent in the topical skin preparation of the present invention is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and from the viewpoint of obtaining a topical skin preparation with excellent usability and stability, particularly preferably 0.5% by mass or more. Furthermore, it is preferably 50% by mass or less, more preferably 40% by mass or less, and from the viewpoint of obtaining a topical skin preparation with excellent usability and stability, particularly preferably 30% by mass or less. When two or more ultraviolet scattering agents are blended in the present invention, the content is the total amount.

[0013] (Titanium oxide) Titanium oxide has the chemical formula TiO 2It is an oxide of titanium represented by the formula: and is also called titanium dioxide or titania, and is used as an ultraviolet scattering agent in sunscreens. When titanium oxide is used in the present invention, hydrophobically treated titanium oxide can be used.

[0014] When titanium oxide is used as the (A) ultraviolet scattering agent in the present invention, the titanium oxide that can be used is not particularly limited as long as it is one that is normally used in topical skin preparations, but from the viewpoint of obtaining a topical skin preparation that is excellent in usability and stability, the average particle size is preferably 0.5 to 1000 nm, more preferably 1 to 500 nm, and particularly preferably 5 to 40. The average particle size of titanium oxide used in the present invention can be measured, for example, by dynamic light scattering.

[0015] When titanium oxide is used as the (A) ultraviolet scattering agent in the present invention, the content of titanium oxide is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and from the viewpoint of obtaining an external skin preparation with excellent usability and stability, particularly preferably 0.5% by mass or more. Also, it is preferably 50% by mass or less, more preferably 40% by mass or less, and from the viewpoint of obtaining an external skin preparation with excellent usability and stability, particularly preferably 30% by mass or less.

[0016] (zinc oxide) Zinc oxide is an oxide of zinc represented by the chemical formula ZnO, and is also known as zinc white or zinc white. It is used as an ultraviolet scattering agent in sunscreens. When zinc oxide is used in the present invention, hydrophobized zinc oxide can be used.

[0017] When zinc oxide is used as the ultraviolet scattering agent (A) in the present invention, the zinc oxide that can be used is not particularly limited as long as it is one that is commonly used in external skin preparations, but from the viewpoint of obtaining an external skin preparation that is excellent in usability and stability, the average particle size is preferably 0.5 to 1000 nm, more preferably 1 to 500 nm, and particularly preferably 5 to 40 nm. The average particle size of the zinc oxide used in the present invention can be measured, for example, by dynamic light scattering.

[0018] When zinc oxide is used as the (A) ultraviolet scattering agent in the present invention, the content of zinc oxide is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and from the viewpoint of obtaining an external skin preparation with excellent usability and stability, particularly preferably 0.5% by mass or more. Also, the content is preferably 50% by mass or less, more preferably 40% by mass or less, and from the viewpoint of obtaining an external skin preparation with excellent usability and stability, particularly preferably 30% by mass or less.

[0019] <(B) Carrageenan> The topical skin preparation of the present invention contains carrageenan. Carrageenan is a seaweed extract obtained from the cell membranes of red algae (scientific name: Rhodophyta, English name: red algae), mainly of the Gigartinaceae family (scientific name: Gigartinaceae) and the Solieriaceae family (scientific name: Solieriaceae), and is a polysaccharide and seaweed-based water-soluble polymer. Examples of carrageenan include iota carrageenan, kappa carrageenan, and lambda carrageenan. Carrageenan that can be used in the present invention is not particularly limited as long as it is one that is typically used in topical skin preparations. However, from the viewpoint of obtaining a topical skin preparation that has excellent usability and stability, iota carrageenan and kappa carrageenan are preferred, and iota carrageenan is particularly preferred.

[0020] The content of (B) carrageenan in the topical skin preparation of the present invention is not particularly limited, but is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, and from the viewpoint of obtaining a topical skin preparation with excellent feel in use and stability, particularly preferably 0.01% by mass or more. Furthermore, it is preferably 10% by mass or less, more preferably 5% by mass or less, and from the viewpoint of obtaining a topical skin preparation with excellent feel in use and stability, particularly preferably 1% by mass or less. When two or more types of carrageenan are blended in the present invention, the content is the total amount.

[0021] <(C) Pectin> The topical skin preparation of the present invention contains pectin. Pectin is a fruit mucilage obtained from the cell membranes of fruits such as apple (scientific name: Malus pumila, English name: Apple) and citrus fruits (scientific name: Citreae) of the Rosaceae family, and vegetables such as carrot (scientific name: Daucus carota subsp. sativus), and is a polysaccharide and a plant-derived water-soluble polymer. The content of (C) pectin in the topical skin preparation of the present invention is not particularly limited, but is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and from the viewpoint of obtaining a topical skin preparation with excellent usability and stability, particularly preferably 0.05% by mass or more. Furthermore, the content is preferably 10% by mass or less, more preferably 5% by mass or less, and from the viewpoint of obtaining a topical skin preparation with excellent usability and stability, particularly preferably 3% by mass or less.

[0022] <(D) Xanthan gum> The topical skin preparation of the present invention can contain xanthan gum. Xanthan gum is a mucilage produced by fermenting carbohydrates with Xanthomonas (scientific name: Xanthomonas campestris), and is a linear polysaccharide and a microbial water-soluble polymer. The content of (D) xanthan gum in the topical skin preparation of the present invention is not particularly limited, but is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and from the viewpoint of obtaining a topical skin preparation with excellent usability and stability, particularly preferably 0.05% by mass or more. The content is also preferably 10% by mass or less, more preferably 5% by mass or less, and from the viewpoint of obtaining a topical skin preparation with excellent usability and stability, particularly preferably 3% by mass or less.

[0023] When the topical skin preparation of the present invention contains (D) xanthan gum, there are no particular restrictions on the contents of the (A) ultraviolet scattering agent, (B) carrageenan, (C) pectin, and (D) xanthan gum. When the content of the (A) ultraviolet scattering agent is taken as 1, the ratio of (A):(B):(C):(D) is preferably 1:0.00005-10:0.0005-10:0.0005-10, more preferably 1:0.0001-5:0.001-5:0.001-5, and from the viewpoint of obtaining a topical skin preparation that is excellent in feel and stability, it is particularly preferably 1:0.0005-3:0.005-3:0.005-3.

[0024] <Other ingredients> In addition to the above-mentioned components, the topical skin preparation of the present invention may contain other components as needed, including one or more of the components typically used in topical skin preparations, such as monohydric alcohols, moisturizers, dispersants, plasticizers, spreading agents, preservatives, fragrances, oils, surfactants, film-forming agents, pH adjusters, deodorants, chelating agents, antioxidants, antibacterial and antifungal agents, anti-inflammatory agents, and whitening agents, as well as animal extracts, plant extracts, cosmetic ingredients, and medicinal ingredients.

[0025] <External skin preparations> The topical skin preparation of the present invention is a composition that is applied to the skin. The topical skin preparation of the present invention preferably has a high viscosity, preferably 1,500 mPa·s or more, more preferably 3,000 mPa·s or more, and from the viewpoint of excellent usability, particularly preferably 5,000 mPa·s or more. The viscosity of the topical skin preparation of the present invention can be measured, for example, using a B-type viscometer (Brookfield rotational viscometer, temperature: 25°C, rotation speed: 5 rpm).

[0026] The pH of the topical skin preparation of the present invention is preferably 4 to 10, and from the viewpoint of excellent usability, more preferably 5 to 9. 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.

[0027] The topical skin preparation of the present invention can be used in pharmaceuticals, quasi-drugs, and cosmetics, such as emulsions, creams, gels, beauty serums, makeup bases, sunscreens, and foundations. Among these, makeup bases and sunscreens are preferred, and sunscreens are particularly preferred.

[0028] The topical skin preparation of the present invention can be produced by a conventional method. For example, when obtaining an oil-in-water composition, an oil phase in which (A) an ultraviolet scattering agent is uniformly dispersed in an oil solution is added to an aqueous phase in which (B) carrageenan, (C) pectin, and optionally a moisturizer, a thickener, and an emulsifier are uniformly dissolved in water, and the oil phase is emulsified uniformly using a homomixer or the like, and the pH is adjusted as necessary to obtain the topical skin preparation of the present invention. [Example]

[0029] 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.

[0030] <Preparation of topical skin preparation> According to Table 1, sunscreen cosmetics of Examples and Comparative Examples were prepared by the following method. Specifically, an aqueous phase was prepared by uniformly dispersing (B) carrageenan and (C) pectin in water. An oil phase prepared by uniformly dispersing (A) an ultraviolet scattering agent in various oils and surfactants was added to the aqueous phase, and the mixture was uniformly emulsified using a homomixer. The pH was then adjusted using sodium hydroxide or citric acid to obtain an oil-in-water sunscreen cosmetic. An oil-in-water sunscreen cosmetic was obtained by the same method as above, except that (D) xanthan gum, when blended, was dispersed in advance in the aqueous phase together with (B) to (C), etc.

[0031] [Table 1]

[0032] <Evaluation of topical skin preparations> (1) Usability rating 1 The resulting topical skin preparations were evaluated for usability. Five subjects in their 20s to 40s with experience using sunscreen cosmetics were randomly selected as test subjects. The topical skin preparations obtained in the above Examples and Comparative Examples were applied to the forearms of the test subjects, and the test subjects were asked to comprehensively evaluate the usability (absence of residue upon application, ease of application, good compatibility, absence of stickiness, moisturizing feeling, and absence of uneven application) based on a 10-point scale. The average value of each item in the questionnaire was calculated and used as the evaluation result. Samples were evaluated after production (day 0 from the date of production) and after storage at 25°C for 24 hours after production. The results are shown in Table 2.

[0033] (No residue) 10: Very good (no residue at all) 8: Good (almost no residue) 5: Normal (a little residue is produced, but not noticeable) 3: Poor (some residue is generated) 1: Very bad (produces a lot of residue)

[0034] (Good stopping ability) 10: Very good (It adheres to the skin very well, and feels like it melts into the skin as it adheres to it) 8: Good (It adheres well to the skin, feels absorbed into the skin, and also feels like it melts slightly) 5: Normal (slightly adheres to the skin and feels absorbed into the skin) 3: Slightly bad (slightly poor adhesion to the skin, not very noticeable absorption) 1: Very bad (it doesn't stick to the skin very well and I don't feel any absorption at all)

[0035] (Familiarity) 10: Very good (blends very well on the skin) 8: Good (blends well on the skin) 5: Normal (blends well on the skin) 3: Fairly bad (doesn't blend well with skin and is bothersome when used) 1: Very bad (does not blend well with skin, not suitable for use)

[0036] (No stickiness) 10: Very good (no stickiness at all) 8: Good (hardly sticky) 5: Normal (slightly sticky, but not noticeable) 3: Slightly bad (slightly sticky and bothersome when using) 1: Very bad (obvious stickiness, not suitable for use)

[0037] (Moisturizing) 10: Very good (very moisturizing and hydrating) 8: Good (moist) 5: Normal (slightly moist) 3: Fairly bad (not very moist) 1: Very bad (not moist at all)

[0038] (No unevenness in the paint) 5: Very good (no uneven application and very easy to spread evenly) 4: Good (almost no unevenness in application, easy to spread evenly) 3: Normal (some unevenness in the paint, but not noticeable) 2: Poor (uneven application and somewhat difficult to spread evenly) 1: Very bad (there are many uneven patches of paint and it is difficult to spread evenly)

[0039] [Table 2]

[0040] The compositions of Examples 1 to 7 of the present invention were superior in texture compared to the comparative examples, both after production (day 0) and after 24 hours of storage at 25°C, with improved lack of residue upon application, good adhesion, good compatibility, lack of stickiness, moisturizing feeling, and lack of uneven application. These results demonstrate that the topical skin preparation of the present invention provides a superior texture by containing (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin. Furthermore, the topical skin preparation of the present invention provides an even superior texture by containing (A) an ultraviolet scattering agent, (B) carrageenan, (C) pectin, and (D) xanthan gum.

[0041] (2) Usability evaluation 2 Furthermore, the topical skin preparations obtained in the above examples were used to comprehensively evaluate the feel (viscosity) of the product, and a questionnaire was conducted based on a five-point scale. The average value of each item in the questionnaire was calculated to represent the evaluation results. The results are shown in Table 3.

[0042] (viscosity) 5: Very good (moderate viscosity, easy to dispense from the container, no dripping when applied) 3: Good (moderate viscosity, easy to take out of the container, hardly drips when applied) 1: Normal (slightly difficult to remove from the container, slight dripping when applied, but not noticeable)

[0043] [Table 3]

[0044] From the above results, it can be seen that the topical skin preparation of the present invention can be obtained as a topical skin preparation with a better feel when used by further containing (D) xanthan gum in addition to (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin.

[0045] (3) Evaluation of storage stability 1 The storage stability of the obtained topical skin preparations was evaluated. The topical skin preparations obtained in the above Examples and Comparative Examples were stored at 5°C, 25°C, and 40°C for 24 hours, and then visually inspected to check for the presence or absence of sample aggregation, and evaluated based on a 10-point scale. The results are shown in Table 4.

[0046] (presence or absence of aggregation) 10: Very good (no clumping observed) 8: Good (almost no clumping observed) 5: Normal (slight agglutination is observed, but not noticeable) 3: Poor (some clumping is observed and changes in appearance are noticeable) 1: Very bad (a lot of clumping observed, and large changes in appearance)

[0047] [Table 4]

[0048] The compositions of Examples 1 to 7 of the present invention exhibited improved aggregation compared to the comparative example after production (day 0) and after 24 hours of storage at 5°C, 25°C, and 40°C, demonstrating excellent stability. Furthermore, stability evaluation revealed that the compositions of Examples 1 to 7 of the present invention exhibited improved aggregation compared to the comparative example, thereby alleviating the deterioration of the appearance of the topical skin preparation and enabling the ingredients incorporated into the topical skin preparation and the effects of the topical skin preparation to be fully exerted. These results demonstrate that the topical skin preparation of the present invention exhibits excellent stability by including (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin. Furthermore, the topical skin preparation of the present invention exhibits even greater stability by including (A) an ultraviolet scattering agent, (B) carrageenan, (C) pectin, and (D) xanthan gum.

[0049] (4) Evaluation of storage stability 2 Furthermore, using the topical skin preparations obtained in the above examples, stability (presence or absence of syneresis) was evaluated, and Examples 1 to 5 were evaluated based on a 10-point scale with Example 1 as the standard. Furthermore, Examples 6 and 7 were evaluated based on a 10-point scale with Example 6 as the standard. The results are shown in Tables 5 and 6.

[0050] (Whether or not water is released) 10: No water separation occurs at all compared to Examples 1 and 6 8: Syneresis is reduced compared to Examples 1 and 6, and almost no syneresis occurs. 5 (reference point): Water separation occurs to the same extent as in Examples 1 and 7, but to an unnoticeable extent. 3: Syneresis is increased compared to Examples 1 and 6 1: Complete water separation compared to Example 1 or 6

[0051] [Table 5]

[0052] [Table 6]

[0053] From the above results, it can be seen that the topical skin preparation of the present invention can be made more stable by further containing (D) xanthan gum in addition to (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin.

[0054] <Preparation of topical skin preparation> The topical skin preparations listed in Table 7 were prepared in the same manner as in Example 1. All of the obtained topical skin preparations were excellent in terms of usability and stability.

[0055] [Table 7] [Industrial Applicability]

[0056] The topical skin preparation of the present invention contains (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin, thereby providing a topical skin preparation that is excellent in usability and stability, and has high potential for industrial application.

Claims

1. A topical skin preparation containing (A) an ultraviolet scattering agent, (B) carrageenan, and (C) pectin.

2. The topical skin preparation according to claim 1, further comprising (D) xanthan gum.

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