External emulsion composition

Abstract

To provide an external emulsion composition which contains urea and is capable of suppressing fluidity increase during storage.SOLUTION: An external emulsion composition contains (A) urea and (B) ceramide 2.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to an external emulsion composition containing urea and capable of suppressing an increase in fluidity due to storage.

Background Art

[0002] Urea has functions such as a moisture retention function by forming hydrogen bonds with moisture in the stratum corneum, and a function of removing or softening unnecessary stratum corneum by protein denaturation, and is used as a component of skin external preparations. However, in an external emulsion composition containing urea, there is a drawback that the fluidity increases due to storage, and liquid dripping easily occurs when applying to the skin.

[0003] Therefore, conventionally, formulation technologies for enhancing the storage stability of external compositions containing urea have been reported. For example, in Patent Document 1, it has been reported that an external composition containing urea, water, and an alkylated water-soluble polymer does not decrease in viscosity even after long-term storage. However, at present, the formulation technology of Patent Document 1 cannot sufficiently suppress the increase in fluidity due to storage.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present disclosure is to provide an external emulsion composition containing urea and capable of suppressing an increase in fluidity due to storage.

Means for Solving the Problems

[0006] The inventor conducted intensive studies to solve the above problems and found that by including ceramide 2 in an external emulsified composition containing urea, an increase in fluidity due to storage can be effectively suppressed, and excellent storage stability can be achieved. The present disclosure was completed by further studies based on such findings.

[0007] That is, the present disclosure provides an external emulsified composition in the following aspects. Item 1. An external emulsified composition containing (A) urea and (B) ceramide 2. Item 2. The external emulsified composition according to Item 1, wherein the content of the (A) urea is 10% by weight or more. Item 3. The external emulsified composition according to Item 1 or 2, which is a cream preparation. Item 4. The external emulsified composition according to any one of Items 1 to 3, which is a pharmaceutical for external use on the skin.

Effects of the Invention

[0008] According to the present disclosure, in an external emulsified composition containing urea, a formulation prescription is provided that can suppress an increase in fluidity due to storage and can suppress dripping when applied to the skin even after storage.

Modes for Carrying Out the Invention

[0009] The external emulsified composition of the present disclosure is characterized by containing (A) urea and (B) ceramide 2. Hereinafter, the external emulsified composition of the present disclosure will be described in detail. In the present disclosure, the description of the numerical range "X to Y" refers to the range of X or more and Y or less.

[0010] [(A) Urea] The external emulsified composition of the present disclosure contains urea. Urea is a known component known to have functions such as moisture retention in the stratum corneum and removal or softening of unnecessary stratum corneum.

[0011] The content of urea in the external emulsion composition of the present disclosure may be appropriately set according to the medicinal effect to be imparted, the use of the external emulsion composition, etc. For example, it is 0.01 to 30% by weight, preferably 1 to 30% by weight, more preferably 3 to 30% by weight. Originally, when the content of urea in the external emulsion composition becomes 10% by weight or more, a tendency for a remarkable increase in fluidity due to storage appears. However, in the external emulsion composition of the present disclosure, even when the content of urea is as high as 10% by weight or more, an increase in fluidity due to storage can be suppressed. In view of such an effect of the external emulsion composition of the present disclosure, the content of urea in the external emulsion composition is more preferably 10% by weight or more, even more preferably 10 to 30% by weight, and particularly preferably 15 to 20% by weight.

[0012] [(B) Ceramide 2] The external emulsion composition of the present disclosure contains ceramide 2 in addition to urea. In the external emulsion composition of the present disclosure, by including ceramide 2, it becomes possible to suppress an increase in fluidity due to storage even though it contains urea.

[0013] Ceramide 2 is N-stearoyl dihydrosphingosine and is one type of human ceramide.

[0014] In the external emulsion composition of the present disclosure, as the ratio of urea to ceramide 2, for example, per 100 parts by weight of urea, ceramide 2 is 0.01 to 300 parts by weight, preferably 0.1 to 200 parts by weight, more preferably 1 to 100 parts by weight.

[0015] Also, the content of ceramide 2 in the external emulsion composition of the present disclosure is 0.001 to 8% by weight, preferably 0.001 to 5% by weight, more preferably 0.01 to 5% by weight. From the viewpoint of more effectively suppressing an increase in fluidity due to storage, the content of ceramide 2 in the external emulsion composition of the present disclosure is more preferably 0.2 to 3% by weight, and particularly preferably 0.5 to 3% by weight.

[0016] [Water] The external emulsified composition of the present disclosure contains water as a base component forming an aqueous phase. Regarding the water content in the external emulsified composition of the present disclosure, it may be appropriately set according to the dosage form and the like. For example, it may be 20 to 97% by weight, preferably 25 to 95% by weight, more preferably 30 to 80% by weight, and still more preferably 35 to 70% by weight.

[0017] [Oil component] The external emulsified composition of the present disclosure contains an oil component as a base component forming an oil phase. The type of the oil component is not particularly limited as long as it is pharmaceutically acceptable. For example, it includes mineral oil, fatty acid alkyl ester, vegetable oil, animal oil, cholesterol, higher fatty acids having 12 to 34 carbon atoms, higher monohydric alcohols having 12 to 34 carbon atoms, silicone oil, and the like.

[0018] Among these oil components, as an example, mineral oil and fatty acid alkyl ester can be mentioned. Specifically, examples of the mineral oil include paraffin, hydrogenated polyisobutene, liquid paraffin, gelled hydrocarbon (such as plastibase), ceresin, microcrystalline wax, petrolatum, and the like. Examples of the fatty acid alkyl ester include esters of fatty acids having 6 to 30 carbon atoms and alcohols having 1 to 34 carbon atoms. Specifically, they include diisopropyl adipate, isopropyl myristate, isopropyl palmitate, cetyl palmitate, diethyl sebacate, ethyl oleate, and the like.

[0019] These oil components may be used alone or in combination of two or more.

[0020] Regarding the content of the oil component in the external emulsified composition of the present disclosure, it may be appropriately set according to the dosage form and the like. For example, it may be 1 to 80% by weight, preferably 5 to 70% by weight, more preferably 5 to 50% by weight, and still more preferably 10 to 40% by weight.

[0021] [Polyhydric alcohol] The external emulsified composition of the present disclosure may contain a polyhydric alcohol as necessary. The type of polyhydric alcohol is not particularly limited as long as it is pharmaceutically acceptable. For example, dihydric alcohols such as ethylene glycol, 1,3-butylene glycol, propylene glycol, isoprene glycol, diethylene glycol, dipropylene glycol, and polypropylene glycol; and trihydric alcohols such as glycerin can be mentioned. Among these polyhydric alcohols, 1,3-butylene glycol is preferably mentioned. These polyhydric alcohols may be used alone or in combination of two or more.

[0022] When the external emulsified composition of the present disclosure contains a polyhydric alcohol, its content is not particularly limited. For example, 1 to 15% by weight, preferably 1 to 10% by weight, more preferably 2 to 8% by weight can be mentioned.

[0023] [Surfactant] The external emulsified composition of the present disclosure may contain a surfactant in order to prepare a desired emulsion type. The surfactant may be any of a nonionic surfactant, an anionic surfactant, a cationic surfactant, or an amphoteric surfactant, but preferably a nonionic surfactant can be mentioned.

[0024] The type of nonionic surfactant is not particularly limited as long as it is pharmaceutically acceptable. For example, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hydrogenated castor oil, glycerin fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene alkyl ether, polyethylene glycol fatty acid ester, lecithin derivative, etc. can be mentioned. Among these, examples of suitable nonionic surfactants include polyoxyethylene sorbitan fatty acid ester and polyoxyethylene hydrogenated castor oil. These nonionic surfactants may be used alone or in combination of two or more.

[0025] When a surfactant is contained in the external emulsion composition of the present disclosure, its content may be appropriately set according to the dosage form, the type of surfactant used, etc. For example, 0.1 to 20% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 8% by weight can be mentioned.

[0026] [Thickener] The external emulsion composition of the present disclosure may contain a thickener as necessary for imparting viscosity or the like. The type of thickener is not particularly limited as long as it is pharmaceutically acceptable. For example, carboxyvinyl polymer, xanthan gum, guar gum, locust bean gum, carrageenan, dextran, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, sodium alginate, propylene glycol alginate ester, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, acrylic acid methacrylic acid alkyl copolymer, sodium polyacrylate bentonite, dextrin fatty acid ester, pectin, etc. can be mentioned. Among these thickeners, carboxyvinyl polymer is preferably mentioned. These thickeners may be used alone or in combination of two or more.

[0027] When the external emulsion composition of the present disclosure contains a thickener, its content is not particularly limited. For example, 0.05 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.1 to 1% by weight can be mentioned.

[0028] [Other components] In addition to the components described above, the external emulsion composition of the present disclosure may contain other commonly used additives as required. Examples of such additives include monohydric lower alcohols, pH adjusters, buffers, solubilizers, preservatives, storage stabilizers, antioxidants, stabilizers, fragrances, colorants, and the like. In the external emulsion composition of the present disclosure, when these additives are contained, the content thereof may be appropriately set according to the type of additive used and the like.

[0029] Further, in addition to the components described above, the external emulsion composition of the present disclosure may contain a pharmacological component. Examples of such pharmacological components include, for example, antihistamines, local anesthetics, moisturizers, bactericides, antibacterial agents, antipruritics, skin protectants, blood circulation promoting components, vitamins, and the like. These pharmacological components may be used alone or in combination of two or more. In the external composition of the present disclosure, when these pharmacological components are contained, the concentration thereof may be appropriately set according to the type of pharmacological component used, the expected effect, and the like.

[0030] [Emulsion type - Dosage form] The emulsion type of the external emulsion composition of the present disclosure may be either oil-in-water type or water-in-oil type, but preferably the oil-in-water type. In the case of the oil-in-water type, the action of ceramide 2 can more effectively suppress the decrease in fluidity due to storage.

[0031] The external emulsion composition of the present disclosure may be either a topical pharmaceutical for skin or a cosmetic, and a topical pharmaceutical for skin is mentioned as a preferred example.

[0032] The dosage form of the external emulsion composition of the present disclosure is not particularly limited, and examples thereof include creams, ointments, emulsions, gels, oils, lotions, liniments, aerosols, and the like. Among these, a cream is a dosage form in which when the fluidity decreases, dripping becomes prominent when applied to the skin, and it is easy to recognize a decrease in the usability, and it is a dosage form in which strong suppression of the decrease in fluidity due to storage is required. Therefore, a cream is mentioned as a preferred dosage form of the external emulsion composition of the present disclosure.

[0033] [Manufacturing Method] The external emulsified composition of the present disclosure can be manufactured according to the formulation methods of known emulsified preparations according to the emulsion type. Specifically, as a manufacturing method of the external emulsified composition of the present disclosure, the components to be contained are divided into water-soluble components and oil components, an aqueous phase containing water-soluble components and an oil phase containing oil components are prepared, and these are emulsified according to known methods. The method can be mentioned.

Examples

[0034] Examples are shown below to more specifically explain the present disclosure, but the present disclosure is not limited thereto.

[0035] Test Example An external emulsified composition (oil-in-water cream) having the compositions shown in Tables 1 and 2 was prepared. Specifically, ceramide 2, pseudo-ceramide (N-(3-hexadecyloxy-2-hydroxypropyl)-N-2-hydroxyethylhexadecanamide), isopropyl myristate, white petrolatum, liquid paraffin, polyoxyethylene hydrogenated castor oil 50, and polysorbate 60 were mixed in predetermined amounts and heated and dissolved at 80°C to prepare an oil-phase composition. Separately, an aqueous-phase composition was prepared by mixing predetermined amounts of urea, 1,3-butylene glycol, carboxyvinyl polymer, and purified water. Next, the aqueous-phase composition heated to 80°C was gradually added to the oil-phase composition heated to 80°C, mixed, and an emulsification operation was performed to obtain an external emulsified composition (oil-in-water cream).

[0036] Six grams of each external emulsion composition immediately after preparation were filled into a 10-ml glass bottle and stored for 5 days under light-shielded conditions at 60°C. Approximately 2 g of each external emulsion composition before and after storage were placed on the inner forearm, and with the upper arm horizontal to the floor and the forearm vertical to the floor (the fingertips upward), the droop resistance of the external emulsion composition was evaluated with the elbow bent. The droop resistance of the external emulsion composition was evaluated on a 5-point scale from 1 to 5, with "not flowing" being "5 points" and "significantly flowing" being "1 point". The evaluation of the droop resistance of each external emulsion composition after storage was performed after returning the product temperature to room temperature.

[0037] The results are shown in Tables 1 and 2. In the external emulsion composition containing no urea and ceramide, no change in fluidity was observed even after storage (Reference Example 1). However, in the external emulsion composition containing urea, the fluidity increased after storage, making it easy to droop on the skin (Comparative Examples 1 to 3). In particular, when the urea content was 10% by weight, the increase in fluidity after storage was remarkable (Comparative Examples 2 and 3). Also, in the external emulsion composition containing urea and pseudo-ceramide, the increase in fluidity after storage could not be suppressed (Comparative Examples 4 and 5). In contrast, in the external emulsion composition containing urea and ceramide 2, the increase in fluidity after storage could be suppressed (Examples 1 to 15). In particular, in the external emulsion composition containing ceramide 2, even when the urea content was 10% by weight or more, the increase in fluidity after storage could be suppressed (Examples 2, 3, 5, 6, 8, 9, 11, 12, 14, and 15). Further, in the external emulsion composition containing urea and 0.5% by weight or more of ceramide 2, the effect of suppressing the increase in fluidity after storage was remarkably high.

[0038] [Table 1]

[0039] [Table 2]

Claims

Claim 1 An external emulsified composition containing (A) urea and (B) ceramide 2. Claim 2 The external emulsified composition according to claim 1, wherein the content of the (A) urea is 10% by weight or more. Claim 3 The external emulsified composition according to claim 1 or 2, which is a cream preparation. Claim 4 The external emulsified composition according to claim 1 or 2, which is a pharmaceutical for external use on the skin.

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