Topical emulsion composition

Abstract

To provide an emulsified composition for external use that comprises urea and a salicylic acid-based anti-inflammatory agent and that can suppress phase separation and decomposition of urea due to storage.SOLUTION: An emulsified composition for external use comprises urea and a salicylic acid-based anti-inflammatory agent, as well as a sorbitan fatty acid ester and / or glycerin fatty acid ester. This emulsified composition for external use can suppress phase separation and decomposition of urea due to storage and exhibit high storage stability.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an emulsion composition for external use which contains urea and a salicylic acid-based anti-inflammatory agent and which can suppress phase separation and decomposition of urea during storage. [Background technology]

[0002] Urea is used in topical compositions because it retains moisture by forming hydrogen bonds with water in the stratum corneum and removes and softens unnecessary keratin through protein denaturation. However, because urea is easily hydrolyzed in topical compositions, stabilization of urea is necessary for topical compositions containing urea. Therefore, various formulations for topical compositions that can stabilize urea have been studied. For example, Patent Document 1 discloses that urea can be stabilized by incorporating a neutral amino acid such as glycine into a topical composition containing urea. Patent Document 2 also discloses that excellent formulation stability can be achieved by incorporating 10 to 25% by weight of urea and retinol or a derivative thereof into a topical composition.

[0003] On the other hand, salicylic acid-based anti-inflammatory agents such as salicylic acid, salicylic acid derivatives, and salts thereof are used in external compositions for anti-inflammatory and analgesic purposes.

[0004] Furthermore, emulsion preparations can be used in a variety of formulations, as they can contain aqueous and oily components, and also have an excellent feel when applied to the skin, making them widely used in the field of external compositions.

[0005] In recent years, consumer demand for improved functionality of topical compositions has increased, and in order to meet such consumer needs, there is a need for the development of an emulsified topical composition containing urea and a salicylic acid-based anti-inflammatory agent. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-97326 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-31159 Summary of the Invention [Problem to be solved by the invention]

[0007] The present inventors have conducted various studies to develop an emulsion composition for topical use containing urea and a salicylic acid-based anti-inflammatory agent, and have found that emulsion compositions for topical use containing urea and a salicylic acid-based anti-inflammatory agent undergo phase separation and decomposition of urea during storage, resulting in problems with storage stability.

[0008] Therefore, an object of the present invention is to provide an emulsified composition for external use that contains urea and a salicylic acid-based anti-inflammatory agent and that can suppress phase separation and decomposition of urea during storage. [Means for solving the problem]

[0009] The present inventors have conducted extensive research to solve the above-mentioned problems and have found that an emulsion composition for topical use containing urea, a salicylic acid-based anti-inflammatory agent, and a sorbitan fatty acid ester and / or a glycerin fatty acid ester can suppress phase separation and urea decomposition during storage, and can have excellent storage stability. Furthermore, the present inventors have also found that the emulsion composition for topical use spreads well when applied around the nails and has an excellent effect of softening the keratin around the nails. The present invention was completed based on these findings and through further research.

[0010] That is, the present invention provides the following aspects. Item 1. An emulsion composition for external use comprising (A) urea, (B) a salicylic acid-based anti-inflammatory agent, and (C) a sorbitan fatty acid ester and / or a glycerin fatty acid ester. Item 2. The emulsion composition for external use according to Item 1, which does not contain glycine. Item 3. The emulsion composition for external use according to Item 1 or 2, further comprising (D) at least one glycyrrhizic acid compound selected from the group consisting of glycyrrhizinic acid, glycyrrhetinic acid, derivatives thereof, and salts thereof. Item 4. The emulsion composition for external use according to any one of Items 1 to 3, further comprising (E) a saturated fatty acid having 14 or more carbon atoms and / or a salt thereof. Item 5. The external emulsion composition according to any one of Items 1 to 4, which is used to soften the keratin around the nails. [Effects of the Invention]

[0011] The topical emulsion composition of the present invention, while containing urea and a salicylic acid-based anti-inflammatory agent, can suppress phase separation and decomposition of urea during storage, thereby providing excellent storage stability. Furthermore, the topical emulsion composition of the present invention has good spreadability when applied around the nails, has an excellent effect of softening the keratin around the nails, and is suitable for use in softening the keratin around the nails. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a photograph showing the appearance of an emulsified composition for external use after storage. DETAILED DESCRIPTION OF THE INVENTION

[0013] 1. Emulsified composition for external use

[0014] The emulsion composition for topical use of the present invention is characterized by containing (A) urea, (B) a salicylic acid-based anti-inflammatory agent, and (C) a sorbitan fatty acid ester and / or a glycerin fatty acid ester. The emulsion composition for topical use of the present invention will be described in detail below.

[0015] [(A)Urea] The topical emulsion composition of the present invention contains urea (sometimes referred to as component (A)). Urea is a well-known component known to have the effect of retaining moisture in the stratum corneum and the effect of removing or softening unnecessary keratin.

[0016] The content of component (A) in the topical emulsion composition of the present invention may be appropriately set depending on the medicinal effect to be imparted, the intended use of the topical emulsion composition, etc., and may be, for example, 1 to 30% by weight, preferably 5 to 25% by weight, and more preferably 10 to 20% by weight. [(B) Salicylic acid-based anti-inflammatory agents] The emulsion composition for external use of the present invention contains a salicylic acid-based anti-inflammatory agent (sometimes referred to as component (B)).

[0017] Specific examples of salicylic acid anti-inflammatory agents include salicylic acid, salicylic acid derivatives, and salts thereof. Examples of salicylic acid derivatives include acetylsalicylic acid (aspirin), salicylic amide (ethenzamide), sulfosalicylic acid, methyl salicylate, ethyl salicylate, glycol salicylate, ethylene glycol salicylate, dipropylene glycol salicylate, titanium salicylate, 2-ethylhexyl salicylate, homomenthyl salicylate, and phenyl salicylate. Examples of salts of salicylic acid and its derivatives include alkali metal salts such as sodium and potassium; and alkaline earth metal salts such as magnesium. These salicylic acid anti-inflammatory agents may be used alone or in combination of two or more.

[0018] Among these salicylic acid-based anti-inflammatory agents, salicylic acid, salts of salicylic acid, ethyl salicylate, and methyl salicylate are preferred, and salicylic acid is more preferred.

[0019] The content of component (B) in the topical emulsion composition of the present invention may be appropriately determined depending on the medicinal effect to be imparted, the intended use of the topical emulsion composition, etc., and may be, for example, 0.01 to 1 wt %, preferably 0.05 to 0.5 wt %, and more preferably 0.1 to 0.5 wt % of the total amount of component (B).

[0020] In the emulsion composition for external use of the present invention, the ratio of component (A) to component (B) is not particularly limited, but for example, the total amount of component (B) is 0.01 to 300 parts by weight, preferably 0.05 to 100 parts by weight, and more preferably 0.1 to 50 parts by weight per 100 parts by weight of component (A).

[0021] [(C) Sorbitan fatty acid ester and / or glycerin fatty acid ester] The topical emulsion composition of the present invention contains a sorbitan fatty acid ester and / or a glycerin fatty acid ester (sometimes referred to as component (C)). In conventional topical emulsion compositions, when component (A) and component (B) are present together, phase separation and decomposition of component (A) occur during storage. However, the topical emulsion composition of the present invention further contains a sorbitan fatty acid ester and / or a glycerin fatty acid ester, thereby making it possible to suppress phase separation and decomposition of component (A) during storage. Furthermore, by containing components (A) to (C), the topical emulsion composition of the present invention spreads well when applied around the nails and has an excellent effect of softening and removing keratin around the nails.

[0022] Sorbitan fatty acid esters are esters of sorbitan and fatty acids and are known nonionic surfactants. The number of fatty acids bonded per molecule of sorbitan fatty acid ester is not particularly limited, but may be, for example, 1 to 4, preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. The number of carbon atoms of the fatty acid constituting the sorbitan fatty acid ester is not particularly limited, but may be, for example, 10 to 22, preferably 14 to 22, and more preferably 16 to 20. Specific examples of sorbitan fatty acid esters include sorbitan monooleate, sorbitan monostearate, sorbitan sesquioleate, sorbitan sesquistearate, sorbitan coconut oil fatty acid, sorbitan monopalmitate, sorbitan tristearate, and sorbitan trioleate. Among these sorbitan fatty acid esters, from the viewpoint of more effectively suppressing phase separation and urea decomposition during storage, preferred are sorbitan monostearate, sorbitan sesquistearate, and sorbitan tristearate, and more preferred are sorbitan monostearate.

[0023] Glycerol fatty acid esters are esters of glycerol and fatty acids and are known nonionic surfactants. The number of carbon atoms in the fatty acids constituting the glycerol fatty acid esters is, for example, 10 to 22, preferably 14 to 22, and more preferably 16 to 20. The number of fatty acids bonded to one glycerol fatty acid molecule is not particularly limited, but may be, for example, 1 to 3, preferably 1 or 2, and more preferably 1. Specific examples of glycerol fatty acid esters include glyceryl monomyristate, glyceryl monostearate, glyceryl monoisostearate, glyceryl monooleate, glyceryl dimyristate, glyceryl distearate, glyceryl diisostearate, and glyceryl dioleate. Among these glycerol fatty acid esters, glyceryl monostearate, glyceryl monomyristate, and glyceryl monoisostearate are preferred from the viewpoint of more effectively suppressing phase separation and urea decomposition during storage.

[0024] The content of component (C) in the emulsion composition for external use of the present invention is, for example, 0.01 to 20 wt %, preferably 0.05 to 10 wt %, more preferably 0.1 to 5 wt %, of the total amount of component (C).

[0025] In the emulsion composition for external use of the present invention, the ratio of component (A) to component (C) is not particularly limited, but for example, the total amount of component (C) is 0.01 to 300 parts by weight, preferably 0.05 to 100 parts by weight, and more preferably 0.1 to 50 parts by weight per 100 parts by weight of component (A).

[0026] [glycine] The emulsified composition for external use of the present invention may contain glycine, but preferably does not contain glycine. Glycine has been known to have the effect of stabilizing urea, but when the emulsified composition for external use of the present invention does not contain glycine, it is possible to more effectively suppress phase separation and decomposition of urea during storage.

[0027] In one embodiment of the emulsified composition for external use of the present invention, the composition does not contain neutral amino acids (amino acids that do not contain an amino group or a carboxyl group in the side chain).

[0028] [(D) Glycyrrhizic acid] In addition to the above-mentioned components, the topical emulsion composition of the present invention may contain at least one glycyrrhizinic acid (sometimes referred to as component (D)) selected from the group consisting of glycyrrhizinic acid, glycyrrhetinic acid, derivatives thereof, and salts thereof. By further including component (D) in the topical composition of the present invention, the effect of inhibiting phase separation and urea decomposition during storage can be further improved, and the spreadability and effect of softening the keratin around the nails when applied around the nails can be further improved.

[0029] Glycyrrhizic acid and glycyrrhetinic acid are known drugs that are known to have anti-inflammatory and anti-allergic effects.

[0030] The derivatives of glycyrrhizinic acid are not particularly limited as long as they are pharmaceutically acceptable, and examples thereof include methyl glycyrrhizinate, stearyl glycyrrhizinate, etc. These derivatives of glycyrrhizinic acid may be used alone or in combination of two or more.

[0031] The derivatives of glycyrrhetinic acid are not particularly limited as long as they are pharmaceutically acceptable, and examples thereof include pyridoxine glycyrrhetinate, stearyl glycyrrhetinate, glyceryl glycyrrhetinate, glycyrrhetinic acid monoglucuronide, etc. These derivatives of glycyrrhetinic acid may be used alone or in combination of two or more.

[0032] The salts of glycyrrhizinic acid, glycyrrhetinic acid and / or their derivatives are not particularly limited as long as they are pharmaceutically acceptable, and examples thereof include alkali metal salts such as sodium salts and potassium salts; ammonium salts, etc. These salts may be used alone or in combination of two or more.

[0033] In the emulsion composition for external use of the present invention, as component (D), one may be selected from glycyrrhizinic acid, glycyrrhetinic acid, derivatives thereof, and salts thereof and used alone, or two or more may be used in combination.

[0034] Of the (D) components, from the viewpoints of inhibiting phase separation and urea decomposition during storage, and further improving spreadability and the effect of softening the keratin around the nails when applied around the nails, preferred are glycyrrhizinic acid and salts thereof, more preferred are salts of glycyrrhizinic acid, and even more preferred is monoammonium glycyrrhizinate.

[0035] When component (D) is contained in the emulsion composition for external use of the present invention, its content is not particularly limited, but may be, for example, 0.05 to 5 wt %, preferably 0.1 to 1 wt %, and more preferably 0.3 to 0.5 wt %, of the total amount of component (D).

[0036] When the topical composition of the present invention contains component (D), the ratio of component (D) to component (A) is not particularly limited, but for example, the total amount of component (D) per 1 part by weight of component (A) is 0.01 to 300 parts by weight, preferably 0.05 to 100 parts by weight, and more preferably 0.1 to 50 parts by weight.

[0037] [(E) Saturated fatty acids having 14 or more carbon atoms and / or salts thereof] The topical emulsion composition of the present invention may contain, as needed, a saturated fatty acid having 14 or more carbon atoms and / or a salt thereof (sometimes referred to as component (E)). When the topical emulsion composition of the present invention further contains component (E), phase separation during storage can be significantly suppressed, and spreadability when applied around the nails can be further improved.

[0038] The saturated fatty acid and / or salt thereof may have 14 or more carbon atoms, but from the viewpoint of more effectively suppressing phase separation during storage and further improving spreadability when applied around the nails, the saturated fatty acid and / or salt thereof preferably has 14 to 30 carbon atoms, more preferably 14 to 24 carbon atoms, even more preferably 14 to 22 carbon atoms, and particularly preferably 18 carbon atoms. More specific examples of saturated fatty acids include myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, and melissic acid; preferably myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid; more preferably myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid; and even more preferably stearic acid.

[0039] Examples of salts of saturated fatty acids having 14 or more carbon atoms include alkali metal salts such as sodium salts and potassium salts.

[0040] In the topical composition of the present invention, one or more saturated fatty acids having 14 or more carbon atoms and salts thereof may be selected and used as component (E), or two or more may be used in combination.

[0041] When component (E) is contained in the emulsion composition for external use of the present invention, its content is not particularly limited, but may be, for example, 0.01 to 10 wt %, preferably 0.1 to 6 wt %, and more preferably 1 to 6 wt %, of the total amount of component (E).

[0042] When the topical emulsion composition of the present invention contains component (E), the ratio of component (A) to component (E) is not particularly limited, but may be, for example, 0.1 to 1200 parts by weight, preferably 0.1 to 100 parts by weight, and more preferably 0.1 to 50 parts by weight of the total amount of component (E) per 100 parts by weight of the total amount of component (A).

[0043] [Polyhydric alcohol] The emulsion composition for external use of the present invention may contain a polyhydric alcohol, if necessary.

[0044] The polyhydric alcohol is not particularly limited as long as it is pharmaceutically acceptable, and examples thereof include 1,3-butylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, glycerin, etc. Among these polyhydric alcohols, glycerin is preferred. These polyhydric alcohols may be used alone or in combination of two or more.

[0045] When the external emulsion composition of the present invention contains a polyhydric alcohol, the content thereof is not particularly limited, but may be, for example, 0.1 to 30% by weight, preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight of the total amount of polyhydric alcohol.

[0046] [Surfactants other than component (C)] The composition for external use on the skin of the present invention may contain a surfactant other than the component (C) as needed.

[0047] Examples of surfactants other than the component (C) include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants other than the component (C). These surfactants may be used alone or in combination of two or more. Among these surfactants, nonionic surfactants are preferred.

[0048] The nonionic surfactants (other than component (C)) used in the present invention are not particularly limited as long as they are pharmaceutically acceptable, and examples thereof include polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil, etc. Among these nonionic surfactants, polyoxyethylene sorbitan fatty acid esters and polyoxyethylene alkyl ethers are preferred.

[0049] The average number of moles of ethylene oxide (EO) added in the polyoxyethylene sorbitan fatty acid ester is not particularly limited, but may be, for example, 5 to 40 moles, preferably 10 to 30 moles, and more preferably 15 to 25 moles. The number of carbon atoms in the fatty acid constituting the polyoxyethylene sorbitan fatty acid ester is not particularly limited, but may be, for example, 10 to 22, preferably 14 to 22, and more preferably 16 to 20. Specific examples of polyoxyethylene sorbitan fatty acid esters include polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, and polyoxyethylene sorbitan monostearate. Among these polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan monostearate (Polysorbate 60), which has an average number of moles of ethylene oxide (EO) added of 20, is particularly preferred.

[0050] The average number of moles of ethylene oxide (EO) added that constitutes the polyoxyethylene alkyl ether is not particularly limited, but may be, for example, 5 to 40 moles, preferably 10 to 30 moles, and more preferably 15 to 25 moles. The number of carbon atoms in the alkyl group that constitutes the polyoxyethylene alkyl ether is not particularly limited, but may be, for example, 10 to 24, preferably 14 to 24, and more preferably 16 to 24. Specific examples of polyoxyethylene alkyl ethers include polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, and polyoxyethylene arachyl ether. Of these polyoxyethylene alkyl ethers, polyoxyethylene arachyl ether is preferred.

[0051] When the emulsion composition for external use of the present invention contains a surfactant (other than component (C)), the content thereof may be appropriately set depending on the formulation, usability, etc., but may be, for example, 0.5 to 20% by weight, preferably 1 to 15% by weight, more preferably 1.5 to 10% by weight in total of surfactants (other than component (C)).

[0052] [Other ingredients] In addition to the above-mentioned components, the topical emulsion composition of the present invention may contain other commonly used additives as needed. Examples of such additives include oily bases other than component (E), water, monohydric lower alcohols, pH adjusters, buffers, solubilizers, antiseptics, preservatives, antioxidants, stabilizers, fragrances, colorants, etc. When these additives are contained in the topical emulsion composition of the present invention, the content thereof may be appropriately determined depending on the type of additive used, etc.

[0053] The topical emulsion composition of the present invention may contain pharmacological ingredients in addition to the above-mentioned ingredients. Examples of such pharmacological ingredients include steroids, antihistamines, local anesthetics, anti-inflammatory agents (other than component (B)), moisturizers (other than component (A)), disinfectants, antibacterial agents, antipruritics, skin protectants, blood circulation promoters, vitamins, mucopolysaccharides, etc. These pharmacological ingredients may be used alone or in combination of two or more. Furthermore, when these pharmacological ingredients are contained in the topical composition of the present invention, their concentrations may be appropriately determined depending on the type of pharmacological ingredient used, the desired effect, etc.

[0054] [Emulsion type / formulation] The emulsion type of the external emulsified composition of the present invention may be either an oil-in-water type or a water-in-oil type, but is preferably an oil-in-water type.

[0055] The formulation of the emulsified composition for external use of the present invention is not particularly limited, and examples thereof include external pharmaceuticals such as creams, emulsions, lotions, liniments, aerosols, etc. Of these, creams are preferred.

[0056] [Application] The use of the topical emulsion composition of the present invention is not particularly limited, but since the topical emulsion composition of the present invention can exert a keratin softening or removal action and a moisturizing action due to component (A) and an anti-inflammatory action due to component (B), it is suitably used for applications such as keratin softening or removal, moisturizing, anti-inflammatory, etc. In particular, the topical emulsion composition of the present invention spreads well when applied around the nails and has an excellent effect of softening the keratin around the nails, so it is suitably used for softening the keratin around the nails.

[0057] [Manufacturing method] The emulsion composition for external use of the present invention can be produced according to a known formulation method for emulsion preparations depending on the emulsion type. For example, a method for producing the emulsion composition for external use of the present invention includes separating the components to be contained into water-soluble components and oily components, preparing an aqueous phase containing the water-soluble components and an oily phase containing the oily components, and emulsifying them according to a known method. [Example]

[0058] The present invention will be explained in more detail below by showing examples, but the present invention is not limited to these examples.

[0059] Test Example 1 Topical emulsion compositions (cream-like oil-in-water emulsion preparations) with the compositions shown in Tables 1 to 3 were prepared. Specifically, the oil phase composition was prepared by first mixing predetermined amounts of surfactants (sorbitan monostearate, sorbitan sesquistearate, sorbitan tristearate, glyceryl monoisostearate, glyceryl monomyristate, glyceryl monostearate, polyoxyethylene hydrogenated castor oil 10, polysorbate 60), fatty acids (stearic acid, myristic acid, palmitic acid, behenic acid, oleic acid, linoleic acid), hydrocarbon oils (white petrolatum, liquid paraffin), cetostearyl alcohol, and a polyoxyethylene-stearyl alcohol mixture and dissolving them by heating at 80°C. Separately, the aqueous phase composition was prepared by mixing predetermined amounts of urea, salicylic acid, glycine, monoammonium glycyrrhizinate, triethanolamine, and water. Next, the aqueous phase composition heated to 80°C was gradually added to the oil phase composition heated to 80°C and mixed to perform an emulsification operation, thereby obtaining an external emulsion composition (a cream-like oil-in-water emulsion preparation). Immediately after production, all of the external emulsion compositions were in an emulsified form without phase separation.

[0060] Each of the obtained emulsion compositions for external use was evaluated for stability of the emulsion state, stability of urea, spreadability when applied around the nails, and keratin softening effect using the following methods.

[0061] <Stability of emulsion> Immediately after preparation, 16 g of each topical emulsion composition was filled into a 20 ml glass bottle and stored at 50°C under light-shielded conditions for one month. The appearance of each topical emulsion composition after one month of storage was visually observed, and the stability of the emulsion state was scored on a scale of 1 to 15, with 15 points representing "no phase separation observed, and the same emulsified state as immediately after preparation was maintained" and 1 point representing "phase separation observed, the emulsified state was not stably maintained, and the emulsion did not become uniform even after shaking." For reference, the appearance of each topical emulsion composition rated as 1 point and 15 points is shown in Figure 1.

[0062] <Stability of urea> Immediately after preparation, 16 g of each topical emulsion composition was filled into a 20 ml glass bottle and stored at 50°C under light-shielded conditions for two months. The urea concentration in each topical emulsion composition before and after two months of storage was quantified by HPLC, and the urea concentration before storage was set to 100% to calculate the residual urea rate (%) after two months of storage, rounded to the nearest whole number. The residual urea rate (%) after two months of storage was classified according to the following criteria. ·Judgment criteria ◎: Urea residual rate is 98-100% ○: Remaining rate of urea is 95-97% △: Remaining rate of urea is 92-94% ×: Remaining rate of urea is 91% or less

[0063] <Spreadability and keratin softening effect when applied around the nails> Ten subjects who were aware of hardening of the stratum corneum around the nails were asked to apply 0.1 g of each topical emulsion composition around the nails once a day for one week, and the spreadability around the nails at the first application and the softening effect on the keratin around the nails after one week of use were evaluated. The spreadability when applied around the nails was evaluated on a five-point scale: "good spreadability," "somewhat good spreadability," "neutral," "somewhat poor spreadability," and "poor spreadability." The total number of subjects who rated the spreadability as "good spreadability" or "somewhat good spreadability" was calculated as the score for spreadability when applied around the nails. In addition, the softening effect on the keratin around the nails was evaluated on a five-point scale: "satisfied," "somewhat satisfied," "neither satisfied nor dissatisfied," "somewhat dissatisfied," and "dissatisfied." The total number of subjects who rated the spreadability as "satisfied" or "somewhat satisfied" was calculated as the score for the softening effect on the keratin around the nails.

[0064] The results are shown in Tables 1 to 3. In the topical emulsion composition containing urea alone, phase separation did not occur during storage and decomposition of urea was inhibited, but the spreadability and keratin softening effect when applied around the nails were insufficient (Reference Example 1). On the other hand, in the topical emulsion composition containing urea and salicylic acid, phase separation was significant during storage, decomposition of urea was observed, and further, the spreadability and keratin softening effect when applied around the nails were insufficient (Comparative Examples 1 and 2).

[0065] In contrast, topical emulsion compositions containing urea and salicylic acid together with sorbitan fatty acid ester and / or glycerin fatty acid ester were able to sufficiently inhibit phase separation and urea decomposition during storage, and furthermore, the spreadability and keratin softening effect when applied around the nails were significantly improved (Examples 1 to 15). Furthermore, when glycine was not included, the decomposition of urea during storage was significantly inhibited (Examples 7 to 15). Furthermore, when monoammonium glycyrrhizinate was included, the effects of inhibiting phase separation and urea decomposition during storage, as well as the spreadability and keratin softening effect when applied around the nails, were significantly improved (Examples 9 to 15). Furthermore, when a saturated fatty acid having 14 or more carbon atoms was further included, the phase separation during storage was significantly inhibited, and the spreadability when applied around the nails was further improved (Examples 11 to 15). Furthermore, topical emulsion compositions were prepared by replacing the salicylic acid in each of the topical emulsion compositions in Comparative Examples 1 and 2 with ethyl salicylate or methyl salicylate, and the emulsion state, urea stability, and spreadability and keratin softening effect when applied around the nails were evaluated using the same method as in Test Example 1. Phase separation and urea decomposition occurred to the same extent as in the corresponding Comparative Examples 1 and 2, and the scores for spreadability and keratin softening effect when applied around the nails were also similar. In contrast, topical emulsion compositions were prepared by replacing the salicylic acid in each of the topical emulsion compositions in Examples 1 to 15 with ethyl salicylate or methyl salicylate, and the emulsion state, urea stability, and spreadability and keratin softening effect when applied around the nails were evaluated using the same method as in Test Example 1. Phase separation and urea decomposition were inhibited to the same extent as in the corresponding Examples 1 to 15, and the scores for spreadability and keratin softening effect when applied around the nails were also similar.

[0066] [Table 1]

[0067] [Table 2]

[0068] [Table 3]

[0069] Prescription example Topical emulsion compositions (creamy oil-in-water emulsion preparations) with the compositions shown in Table 4 were prepared. The emulsion state, urea stability, spreadability when applied around the nails, and keratin softening effect were evaluated using the same methods as in Test Example 1. All of the topical emulsion compositions in Formulation Examples 1 to 7 were able to sufficiently suppress phase separation and urea decomposition during storage, and also showed excellent spreadability and keratin softening effect when applied around the nails.

[0070] [Table 4]

Claims

1. (A) urea, (B) a salicylic acid-based anti-inflammatory agent, (C) a sorbitan fatty acid ester and / or a glycerin fatty acid ester, and (D) at least one glycyrrhizic acid compound selected from the group consisting of glycyrrhizic acid, glycyrrhetinic acid, derivatives thereof, and salts thereof, the sorbitan fatty acid ester is at least one selected from the group consisting of sorbitan monostearate, sorbitan sesquistearate, sorbitan cocoate, and sorbitan tristearate; An emulsion composition for external use, wherein the glycerin fatty acid ester is at least one selected from the group consisting of glyceryl monomyristate, glyceryl monoisostearate, glyceryl monooleate, glyceryl dimyristate, glyceryl distearate, glyceryl diisostearate, and glyceryl dioleate.

2. (A) urea, (B) a salicylic acid-based anti-inflammatory agent, and (C) a sorbitan fatty acid ester and / or a glycerin fatty acid ester, the sorbitan fatty acid ester is at least one selected from the group consisting of sorbitan monostearate, sorbitan sesquistearate, sorbitan cocoate, and sorbitan tristearate; the glycerin fatty acid ester is at least one selected from the group consisting of glyceryl monomyristate, glyceryl monoisostearate, glyceryl monooleate, glyceryl dimyristate, glyceryl distearate, glyceryl diisostearate, and glyceryl dioleate; An external emulsion composition for softening the cuticles around the nails.

3. 3. The emulsion composition for external use according to claim 2, further comprising (D) at least one glycyrrhizic acid compound selected from the group consisting of glycyrrhizinic acid, glycyrrhetinic acid, derivatives thereof, and salts thereof.

4. The emulsion composition for external use according to any one of claims 1 to 3, further comprising (E) a saturated fatty acid having 14 or more carbon atoms and / or a salt thereof.

5. The external emulsion composition according to any one of claims 1 to 4, which does not contain glycine.

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