External 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 saturated fatty acid having 14 or more carbon atoms and / or a salt thereof and a lipophilic surfactant. 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 wide range of formulations, including 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, in addition to urea and a salicylic acid-based anti-inflammatory agent, a saturated fatty acid having 14 or more carbon atoms and / or its salt and a lipophilic surfactant can suppress phase separation and decomposition of urea during storage and has excellent storage stability. The present invention was completed based on this finding 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, (C) a saturated fatty acid having 14 or more carbon atoms and / or a salt thereof, and (D) a lipophilic surfactant. Item 2. The emulsion composition for external use according to Item 1, wherein the component (D) is at least one selected from the group consisting of sorbitan fatty acid esters, glycerin fatty acid esters, and polyoxyethylene hydrogenated castor oil. Item 3. The emulsion composition for external use according to Item 1 or 2, which does not contain glycine. [Effects of the Invention]

[0011] According to the emulsion composition for external use of the present invention, even though it contains urea and a salicylic acid-based anti-inflammatory agent, phase separation and decomposition of urea due to storage can be suppressed, and excellent storage stability can be achieved. [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 The emulsified composition for topical use of the present invention is characterized by containing (A) urea, (B) a salicylic acid-based anti-inflammatory agent, (C) a saturated fatty acid having 14 or more carbon atoms and / or a salt thereof, and (D) a lipophilic surfactant. The emulsified composition for topical use of the present invention will be described in detail below.

[0014] [(A)Urea] The emulsion composition for external use 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.

[0015] 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.

[0016] [(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), salicylamide (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.

[0018] These salicylic acid-based anti-inflammatory agents may be used alone or in combination of two or more.

[0019] 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.

[0020] 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).

[0021] 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).

[0022] [(C) Saturated fatty acids having 14 or more carbon atoms and / or salts thereof] The emulsion composition for external use of the present invention contains a saturated fatty acid having 14 or more carbon atoms and / or a salt thereof (sometimes referred to as component (C)).

[0023] The saturated fatty acid and / or salt thereof may have 14 or more carbon atoms, but from the viewpoint of more effectively inhibiting phase separation and urea decomposition during storage, 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.

[0024] Examples of salts of saturated fatty acids having 14 or more carbon atoms include alkali metal salts such as sodium salts and potassium salts.

[0025] 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 (C), or two or more may be used in combination.

[0026] The content of component (C) in the external emulsion composition of the present invention is not particularly limited, but may be, for example, 0.01 to 10% by weight, preferably 0.1 to 6% by weight, and more preferably 1 to 6% by weight, of the total amount of component (C).

[0027] 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 0.1 to 1200 parts by weight, preferably 0.1 to 100 parts by weight, and more preferably 0.1 to 50 parts by weight per 100 parts by weight of component (A).

[0028] [(D) Lipophilic surfactant] The emulsified composition for external use of the present invention contains a lipophilic surfactant (sometimes referred to as component (D)).

[0029] In the present invention, a lipophilic surfactant is a surfactant that has a higher affinity for oily agents than for water. Specific examples of lipophilic surfactants include nonionic surfactants having an HLB value of 8 or less, preferably an HLB value of 1 to 8, and more preferably an HLB value of 2 to 6.5. In the present invention, the HLB value of a surfactant is a value calculated according to the Kawakami method (HLB value = 7 + 11.7 log (total formula weights of hydrophilic moieties / total formula weights of lipophilic moieties)).

[0030] Examples of lipophilic surfactants include nonionic surfactants such as sorbitan fatty acid esters, glycerin fatty acid esters, polyoxyethylene hydrogenated castor oil, polyglycerin fatty acid esters, and propylene glycol fatty acid esters, which satisfy the above HLB value.

[0031] Among these lipophilic surfactants, from the viewpoint of more effectively suppressing phase separation and urea decomposition due to storage, preferred are sorbitan fatty acid esters, glycerin fatty acid esters, and polyoxyethylene hydrogenated castor oil, and more preferred are sorbitan fatty acid esters and glycerin fatty acid esters.

[0032] The number of carbon atoms of the fatty acid constituting the sorbitan fatty acid ester is, for example, 10 to 22, preferably 14 to 22, and more preferably 16 to 20. The number of fatty acids bonded per molecule of the sorbitan fatty acid ester is, for example, 1 to 4, and preferably 1 to 3. Specific examples of sorbitan fatty acid esters include sorbitan monooleate, sorbitan monostearate, sorbitan sesquioleate, sorbitan coconut oil fatty acid, sorbitan monopalmitate, sorbitan tristearate, and sorbitan trioleate. Among these sorbitan fatty acid esters, preferred are sorbitan monostearate, sorbitan sesquistearate, and sorbitan tristearate, and more preferred are sorbitan monostearate.

[0033] The number of carbon atoms in the fatty acid constituting the glycerin fatty acid ester is, for example, 10 to 22, preferably 14 to 22, and more preferably 16 to 20. The number of fatty acids bonded to one molecule of the glycerin fatty acid is not particularly limited, but may be, for example, 1 to 3, preferably 1 or 2, and more preferably 1. Specific examples of the glycerin fatty acid ester include glyceryl monomyristate, glyceryl monostearate, glyceryl monoisostearate, glyceryl monooleate, glyceryl dimyristate, glyceryl distearate, glyceryl diisostearate, and glyceryl dioleate. Of these glycerin fatty acid esters, glyceryl monostearate and glyceryl monomyristate are preferred.

[0034] The average number of moles of ethylene oxide (EO) added in the polyoxyethylene hydrogenated castor oil is, for example, 3 to 100 moles, preferably 3 to 50 moles, and more preferably 3 to 20 moles. Specific examples of the polyoxyethylene hydrogenated castor oil include polyoxyethylene hydrogenated castor oil 5 and polyoxyethylene hydrogenated castor oil 10. Of these polyoxyethylene hydrogenated castor oils, polyoxyethylene hydrogenated castor oil 10 is preferred.

[0035] These lipophilic surfactants may be used alone or in combination of two or more.

[0036] The content of component (D) in the external emulsion composition of the present invention is not particularly limited, but may be, for example, 0.01 to 20% by weight, preferably 0.05 to 10% by weight, and more preferably 0.2 to 5% by weight, of the total amount of component (D).

[0037] In the emulsion composition for external use of the present invention, the ratio of component (A) to component (D) is not particularly limited, but for example, the total amount of component (D) is 0.01 to 500 parts by weight, preferably 0.05 to 200 parts by weight, and more preferably 0.1 to 50 parts by weight per 100 parts by weight of component (A).

[0038] [Glycine, Neutral Amino Acid] 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 the decomposition of urea during storage.

[0039] 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).

[0040] [Hydrophilic surfactants] The emulsion composition for external use of the present invention may contain a hydrophilic surfactant as needed. In the present invention, the hydrophilic surfactant is a surfactant that has a higher affinity for water than for oils. Specific examples of the hydrophilic surfactant include nonionic surfactants with an HLB value of more than 8.

[0041] Examples of hydrophilic surfactants include nonionic surfactants that satisfy the above HLB value, such as polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, glycerin fatty acid esters, polyglycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, polyoxyethylene hydrogenated castor oil, polyethylene glycol fatty acid esters, and lecithin derivatives. Among these hydrophilic surfactants, polyoxyethylene sorbitan fatty acid esters and polyoxyethylene alkyl ethers are preferred from the viewpoint of more effectively suppressing phase separation and urea decomposition during storage.

[0042] The average number of moles of ethylene oxide (EO) added in the polyoxyethylene sorbitan fatty acid ester is, for example, 5 to 50 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, 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, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan monolaurate. 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 preferred.

[0043] The average number of moles of ethylene oxide (EO) added in the polyoxyethylene alkyl ether is, for example, 2 to 50 moles, preferably 5 to 30 moles, and more preferably 15 to 25 moles. The number of carbon atoms in the alkyl group constituting 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, polyoxyethylene behenyl ether, and polyoxyethylene arachyl ether. Among these polyoxyethylene alkyl ethers, polyoxyethylene arachyl ether is preferred from the viewpoint of more effectively suppressing discoloration during storage.

[0044] When a hydrophilic surfactant is contained in the emulsion composition for external use of the present invention, the content thereof is not particularly limited, but may be, for example, 0.5 to 20% by weight, preferably 1 to 15% by weight, and more preferably 1.5 to 5% by weight, of the total amount of hydrophilic surfactant.

[0045] [Polyhydric alcohol] The emulsion composition for external use of the present invention may contain a polyhydric alcohol, if necessary.

[0046] 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.

[0047] 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.

[0048] [Oil base other than component (C)] The topical emulsion composition of the present invention may further contain an oily base other than the component (C) as necessary, for example, to prepare a desired formulation. The oily base other than the component (C) is not particularly limited as long as it is pharmaceutically acceptable, and examples thereof include higher alcohols, hydrocarbon oils, fatty acid alkyl esters, vegetable oils, animal oils, and silicone oils. These oily bases (other than the component (C)) may be used alone or in combination of two or more. Among these oily bases (other than the component (C)), higher alcohols and hydrocarbon oils are preferred.

[0049] The higher alcohol is not particularly limited as long as it is pharmaceutically acceptable, and examples thereof include monohydric alcohols having 12 to 34 carbon atoms, specifically lauryl alcohol, cetanol, stearyl alcohol, cetostearyl alcohol, oleyl alcohol, arachidyl alcohol, behenyl alcohol, myricyl alcohol, geddyl alcohol, etc. Among these higher alcohols, stearyl alcohol and cetostearyl alcohol are preferred.

[0050] The hydrocarbon oil is not particularly limited as long as it is pharmaceutically acceptable, and examples thereof include liquid paraffin, α-olefin oligomer, petrolatum, microcrystalline wax, gelled hydrocarbon (Plastibase, etc.), hydrogenated polyisobutene, etc. Among these hydrocarbon oils, liquid paraffin and petrolatum are preferred.

[0051] When an oily base (other than component (C)) is contained in the emulsion composition for external use of the present invention, its content may be appropriately set depending on the formulation form, usability, etc., and may be, for example, 5 to 80% by weight, preferably 10 to 60% by weight, more preferably 10 to 30% by weight, of the total amount of oily base (other than component (C)).

[0052] [Other ingredients] In addition to the above-mentioned components, the emulsion composition for external use of the present invention may contain other commonly used additives as needed. Examples of such additives include monohydric lower alcohols, aqueous bases, pH adjusters, buffers, solubilizers, antiseptics, preservatives, antioxidants, stabilizers, fragrances, colorants, water, etc. When these additives are contained in the emulsion composition for external use 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 effect and a moisturizing effect due to component (A) and an anti-inflammatory effect due to component (B), it is preferably used for applications such as keratin softening or removal, moisturizing, anti-inflammatory, etc. In particular, since the topical emulsion composition of the present invention has an excellent effect of softening the keratin around the nails, it is preferably 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-type oil-in-water emulsion preparations) with the compositions shown in Tables 1 and 2 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 the mixture by heating at 80°C. Separately, the aqueous phase composition was prepared by mixing predetermined amounts of urea, salicylic acid, glycine, 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] The stability of the emulsified state and the stability of urea in each of the obtained emulsion compositions for external use were evaluated by 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] The results are shown in Tables 1 and 2. In the topical emulsion composition containing urea alone, phase separation did not occur during storage, and decomposition of urea was also suppressed (Reference Example 1). On the other hand, in the topical emulsion composition containing urea and salicylic acid, phase separation was significantly observed during storage, and decomposition of urea was also observed (Comparative Examples 1 to 4). Furthermore, even when a lipophilic surfactant (polyoxyethylene hydrogenated castor oil 10) and an unsaturated fatty acid having 14 or more carbon atoms were combined with urea and salicylic acid, phase separation and decomposition of urea during storage could not be suppressed (Comparative Examples 3 and 4).

[0064] In contrast, in topical emulsion compositions containing urea and salicylic acid, as well as a lipophilic surfactant and a saturated fatty acid having 14 or more carbon atoms, phase separation and urea decomposition during storage were sufficiently suppressed (Examples 1 to 12). In particular, when sorbitan monostearate was used as the lipophilic surfactant, phase separation during storage was significantly suppressed (Examples 5 and 11). Furthermore, when glycine was not included, urea decomposition during storage was significantly suppressed (Examples 11 and 12). Furthermore, topical emulsion compositions were prepared by replacing the salicylic acid in each of the topical emulsion compositions of Comparative Examples 1 to 4 with ethyl salicylate or methyl salicylate, and the emulsified state and urea stability were evaluated in the same manner as in Test Example 1. Phase separation and urea decomposition occurred to the same extent as in the corresponding Comparative Examples 1 to 4. In contrast, topical emulsion compositions were prepared in which the salicylic acid in each of the topical compositions of Examples 1 to 12 was replaced with ethyl salicylate or methyl salicylate, and the emulsion state and urea stability were evaluated in the same manner as in Test Example 1. Phase separation and urea decomposition were suppressed to the same extent as in the corresponding Examples 1 to 12.

[0065] [Table 1]

[0066] [Table 2]

[0067] Prescription example Topical emulsion compositions (creamy oil-in-water emulsion preparations) were prepared with the compositions shown in Table 3. The emulsion state and urea stability were evaluated using the same method as in Test Example 1. All of the topical emulsion compositions of Formulation Examples 1 to 9 were able to sufficiently suppress phase separation and urea decomposition during storage.

[0068] [Table 3]

Claims

1. (A) urea, (B) a salicylic acid-based anti-inflammatory agent, (C) a saturated fatty acid having 14 or more carbon atoms and / or a salt thereof, and (D) a lipophilic surfactant, the component (D) is at least one selected from the group consisting of sorbitan fatty acid esters, glycerin fatty acid esters, and polyoxyethylene hydrogenated castor oil; 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. The topical emulsion composition according to claim 1, which does not contain glycine.

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