JP2020203847A - Emulsion composition - Google Patents

Abstract

To provide an emulsion composition containing ufenamate and isopropylmethylphenol, the emulsion composition having excellent emulsion stability.SOLUTION: An emulsion composition has (A) ufenamate and (B) isopropylmethylphenol blended with (C) lidocaine, providing excellent emulsion stability.SELECTED DRAWING: None

Description

The present invention relates to an emulsified composition containing ufenamate and isopropylmethylphenol, which is excellent in property stability.

The emulsified composition can contain an aqueous component and an oily component, can be used in various formulations, and has an excellent usability when applied to the skin. Therefore, the emulsified composition is widely used in the fields of external medicines and cosmetics.

Ufenamart is used as a non-steroidal anti-inflammatory drug in combination with a pharmaceutical product or a quasi-drug skin external preparation. Ufenamart is a poorly water-soluble component and can be formulated as an emulsifying composition. For example, in Patent Document 1, a skin external preparation containing a non-steroidal anti-inflammatory drug such as ufenamate and a specific amide derivative and which can be an emulsified dosage form is only excellent in long-lasting drug effect. It is described that the skin itself is moisturized, the skin irritation is low, the effect of improving rough skin is excellent, and the feeling of use is good.

In addition, isopropylmethylphenol has a wide range of bactericidal activity and high safety, and is used as an antibacterial agent in combination with a cleansing agent and an external preparation for skin. Isopropylmethylphenol is also a poorly water-soluble component and can be formulated as an emulsifying composition. For example, Patent Document 2 describes an emulsified deodorant composition containing a polyether-modified silicone, a (dimethicone / vinyl dimethicone) crosspolymer, 2-ethylhexyl palmitate, an antiperspirant, a bactericide, and water. It is described that isopropylmethylphenol is blended as a disinfectant, and the composition dramatically enhances the residual property of the disinfectant on the object to be coated after application.

On the other hand, lidocaine is used as a local anesthetic or antipyretic anti-inflammatory agent in combination with a pharmaceutical product or a quasi-drug skin external preparation. For example, Patent Document 3 describes an anti-inflammatory pharmaceutical composition containing tranexamic acid or a salt thereof, and a local anesthetic, and describes that lidocaine is used as the local anesthetic. Patent Document 4 describes a composition for external use that imparts a refreshing sensation containing menthol, a medium component, and a transdermally absorbable medicinal ingredient, and an antipyretic anti-inflammatory agent such as lidocaine is described as the transdermal medicinal ingredient. It is stated that it will be used. Patent Document 5 describes at least one of a predetermined amount of an antihistamine hydrochloride and a local anesthetic hydrochloride, a predetermined amount of ethanol, a predetermined amount of borosand and / or boric acid, and an organic acid and / or organic. An external composition containing a base is described, and it is described that lidocaine hydrochloride is used as a hydrochloride of a local anesthetic.

JP-A-11-302198 International Publication No. 2016/052277 Japanese Unexamined Patent Publication No. 2007-277222 Japanese Unexamined Patent Publication No. 2014-152172 JP-A-2017-190314

The emulsified compositions described in Patent Document 1 and Patent Document 2 have been examined for their medicinal properties, irritation, usability, etc., but their property stability has not been examined. The present inventor focused on a formulation in which both ufenamate and isopropylmethylphenol were blended in the emulsified composition, and prepared an emulsified composition containing these components, but the properties such as separation from the emulsified composition after storage, etc. Faced the challenge of instability.

Therefore, an object of the present invention is to provide an emulsified composition containing ufenamate and isopropylmethylphenol, which has excellent emulsification stability.

As a result of diligent studies on an emulsified composition containing ufenamate and isopropylmethylphenol, the present inventor surprisingly blends lidocaine and / or a salt thereof, which has not been known to have an emulsion stabilizing effect. It was found that it has excellent emulsion stability. The present invention has been completed by further studies based on this finding.

That is, the present invention provides the inventions of the following aspects.
Item 1. An emulsified composition containing (A) ufenamate, (B) isopropylmethylphenol, and (C) lidocaine and / or a salt thereof.
Item 2. Item 2. The emulsified composition according to Item 1, which contains the component (C) in a total amount of 0.1 to 5% by weight.
Item 3. Item 2. The emulsified composition according to Item 1 or 2, wherein the component (C) is contained in a total amount of 0.005 to 5 parts by weight per part by weight of the component (A).
Item 4. Item 3. The emulsified composition according to any one of Items 1 to 3, wherein the component (C) is contained in a total amount of 0.03 to 500 parts by weight per part by weight of the component (B).
Item 5. Item 2. The emulsified composition according to any one of Items 1 to 4, which contains an oil selected from the group consisting of higher alcohols, ester oils, liquid hydrocarbon oils, and silicone oils.
Item 6. Item 2. The emulsified composition according to any one of Items 1 to 5, which contains a nonionic surfactant selected from the group consisting of glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, and polyethylene glycol fatty acid ester.
Item 7. A method for stabilizing emulsion, which comprises blending (C) lidocaine and / or a salt thereof together with the component (A) and the component (B) in an emulsification composition containing (A) ufenamate and (B) isopropylmethylphenol.

According to the present invention, an emulsified composition containing ufenamate and isopropylmethylphenol can be provided with excellent emulsification stability.

1. 1. Emulsification Composition The emulsified composition of the present invention includes (A) ufenamate (hereinafter, also referred to as "(A) component"), (B) isopropylmethylphenol (hereinafter, also referred to as "(B) component"), and It is characterized by containing (C) lidocaine and / or a salt thereof (hereinafter, also referred to as "component (C)"). Hereinafter, the emulsified composition of the present invention will be described in detail.

(A) Ufenamart The emulsified composition of the present invention contains Ufenamart as a component (A). Ufenamate, also referred to as butyl flufenamic acid, is a known component as a poorly water-soluble non-steroidal anti-inflammatory drug.

In the emulsified composition of the present invention, the content of the component (A) is appropriately set according to the medicinal effect to be imparted, and is, for example, 1 to 20% by weight, preferably 2 to 10% by weight, more preferably. 3 to 7% by weight is mentioned.

(B) Isopropylmethylphenol The emulsified composition of the present invention contains isopropylmethylphenol as a component (B). Isopropylmethylphenol, also referred to as 3-methyl-4-isopropylphenol or cymene-5-ol, is a known component as a poorly water-soluble fungicide.

The blending amount of the component (B) in the emulsified composition of the present invention is not particularly limited and can be appropriately determined according to the medicinal effect to be imparted, but for example, 0.01 to 3% by weight, preferably 0.02 to 02-. 2.0% by weight, more preferably 0.02 to 1.5% by weight, still more preferably 0.01 to 1% by weight, still more preferably 0.05 to 0.5% by weight, particularly preferably 0.07 to 0.07% by weight. 0.3% by weight is mentioned.

(C) Lidocaine and / or a salt thereof The emulsified composition of the present invention contains lidocaine and / or a salt thereof as a component (C). Lidocaine, also referred to as 2- (diethylamino) -N- (2,6-dimethylphenyl) acetamide, is a known drug known to have a local anesthetic effect. The emulsified composition containing the component (A) and the component (B) has poor emulsion stability, but in the emulsified composition of the present invention, excellent emulsification stability is exhibited by blending the component (C).

The salt of lidocaine is not particularly limited as long as it is pharmaceutically acceptable, and specific examples thereof include inorganic acid salts such as hydrochloride.

In the emulsified composition of the present invention, one kind may be selected from lidocaine and a salt thereof and used alone, or two or more kinds may be used in combination. Among lidocaine and salts thereof, lidocaine and lidocaine hydrochloride (xylocaine) are preferably mentioned, and lidocaine is more preferable.

The content of the component (C) in the emulsified composition of the present invention is not particularly limited, and the total amount of lidocaine and its salt is, for example, 0.1 to 5% by weight. From the viewpoint of obtaining even better emulsion stability, the content of the component (C) is preferably 0.2 to 5.0% by weight, more preferably 0.5 to 5.0% by weight, 0.5 to 0.5 to It may be 4.0% by weight, or 0.5 to 3.0% by weight.

Further, since the emulsified composition of the present invention is excellent in emulsification stability, even when the component (C) is less than the original effective amount as a local anesthetic or antipyretic anti-inflammatory agent, it is effectively emulsified and stabilized. The effect can be obtained. From this point of view, the content of the component (C) in the emulsified composition of the present invention is the total amount of lidocaine and a salt thereof, for example, 0.1 to 0.4% by weight and 0.1 to 0.3% by weight. , 0.1 to 0.2% by weight, or 0.2 to 0.3% by weight.

In the emulsified composition of the present invention, the ratio of the component (C) to the component (A) is determined according to the contents of the component (A) and the component (C), but further excellent emulsification stability is obtained. From the viewpoint, for example, the content of the component (C) per part by weight of the component (A) is 0.005 to 5 parts by weight, preferably 0.02 to 2 parts by weight, based on the total amount of lidocaine and its salt. More preferably, 0.1 to 0.7 parts by weight, 0.1 to 0.6 parts by weight, or 0.1 to 0.5 parts by weight can be mentioned.

In the emulsified composition of the present invention, the ratio of the component (C) to the component (B) is determined according to the contents of the component (B) and the component (C), but further excellent emulsification stability is obtained. From the viewpoint, for example, the content of the component (C) per part by weight of the component (B) is 0.03 to 500 parts by weight, preferably 0.1 to 200 parts by weight, based on the total amount of lidocaine and its salt. More preferably, 2 to 50 parts by weight, still more preferably 5 to 30 parts by weight, or 5 to 25 parts by weight.

In the emulsified composition of the present invention, the ratio of the component (C) to the sum of the components (A) and (B) depends on the respective contents of the components (A), (B) and (C). However, from the viewpoint of obtaining even better emulsion stability, for example, the content of the component (C) per 1 part by weight of the components (A) and (B) is, for example, the total amount of lidocaine and its salt. 0.004 to 5 parts by weight, preferably 0.01 to 2 parts by weight, more preferably 0.04 to 0.7 parts by weight, still more preferably 0.09 to 0.6 parts by weight, or 0.09. ~ 0.5 parts by weight can be mentioned.

Oil content The emulsified composition of the present invention contains an oil content as a base component of the oil phase. The oil content is not particularly limited as long as it is pharmaceutically or cosmetically acceptable, and examples thereof include liquid oils, solid oils, and higher alcohols. These oils may be used alone or in combination of two or more.

The oil content in the emulsified composition of the present invention may be appropriately set according to the emulsified type, form, application, etc. of the emulsified composition, and is, for example, 5 to 60% by weight, preferably 7 to 30% by weight. , More preferably 10 to 15% by weight.

(Liquid oil)
The liquid oil is an oil that maintains a liquid form at 25 ° C. The liquid oil used in the present invention may be any liquid oil usually used for cosmetics, external pharmaceuticals and the like, for example; fatty acids such as oleic acid and instearic acid; cetyl ethylhexaneate, ethylhexyl palmitate, myristin. Ester oils such as octyldodecyl acid, neopentylglycol diethylhexaneate, glyceryl tri2-ethylhexanoate, octyldodecyl oleate, isopropyl myristate, glyceryl triisostearate, glyceryl dibaramethoxysilicate-monoethylhexanoate; dimethyl Silicone oils such as polysiloxane, methylhydrodienepolysiloxane, methylphenylpolysiloxane, octamethylcyclotetrasiloxane; liquid hydrocarbon oils such as liquid paraffin, squalane, and squalane may be mentioned.

Among these liquid oils, ester oil, silicone oil, and liquid hydrocarbon oil are preferable, and isopropyl myristate, dimethylpolysiloxane, and liquid paraffin are more preferable, from the viewpoint of better emulsion stability. ..

These liquid oils may be used alone or in combination of two or more.

When the emulsification stabilizer of the present invention contains a liquid oil, the content thereof is not particularly limited and may be appropriately set according to the emulsification type, form, application and the like of the emulsification composition. 0.01 to 30% by weight, preferably 0.1 to 20% by weight, more preferably 1 to 15% by weight, still more preferably 5 to 10% by weight.

When the emulsion stabilizer of the present invention contains an ester oil, the content thereof is 0.2 to 3.5% by weight, preferably 0.3 to 3.5% by weight, from the viewpoint of obtaining more excellent emulsion stability. 2% by weight, more preferably 0.5 to 1% by weight.

When the emulsion stabilizer of the present invention contains silicone oil, the content thereof is 0.3 to 2% by weight, preferably 0.5 to 1, from the viewpoint of obtaining more excellent emulsion stability. 5% by weight, more preferably 0.7 to 1% by weight.

(Solid oil)
The solid oil is an oil that maintains a solid form at 25 ° C. The solid oil used in the present invention may be any solid oil usually used for cosmetics, external medicines, etc., for example, candelilla wax, rice bran wax, honey wax, cotton wax, carnauba wax, lanolin, cellac wax, ozokerite, ceresin, Polyethylene wax, microcrystalin wax, vaseline, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, undecylenic acid, myristyl myristate, cetyl myristate, stearyl stearate, cetyl stearate, palmitin Examples thereof include solid oils such as cetyl acidate, cholesteryl stearate, cholesteryl oleate, dextrin palmitate, inulin stearate, hydrogenated jojoba oil, selecin wax, solid paraffin wax, polyethylene wax and silicone wax.

These solid oils may be used alone or in combination of two or more.

When the emulsified composition of the present invention contains solid oil, the content thereof is not particularly limited and may be appropriately set according to the emulsified type, form, use and the like of the emulsified composition. 1 to 50% by weight, preferably 1 to 30% by weight, more preferably 5 to 15% by weight.

(Higher alcohol)
The higher alcohol is a monohydric alcohol having 6 or more carbon atoms in one molecule. The number of carbon atoms in one molecule of the higher alcohol used in the present invention may be 6 or more, preferably 6 to 34, and more preferably 14 to 22.

The higher alcohol used in the present invention may be any alcohol usually used for cosmetics, external medicines, etc. For example, myristyl alcohol, cetyl alcohol (cetyl alcohol), oleyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, etc. Lanolin alcohol and the like can be mentioned.

Among these higher alcohols, cetyl alcohol (cetyl alcohol) and lanolin alcohol are preferable from the viewpoint of obtaining more excellent emulsion stability.

These higher alcohols may be used alone or in combination of two or more.

When the emulsified composition of the present invention contains a higher alcohol, the content thereof is not particularly limited and may be appropriately set according to the emulsified type, form, use and the like of the emulsified composition. 1 to 50% by weight, preferably 1 to 30% by weight, more preferably 2 to 15% by weight, still more preferably 3 to 10% by weight.

When the liquid oil and the higher alcohol are used in combination in the emulsified composition of the present invention, the ratio thereof is not particularly limited, but for example, the content of the higher alcohol per 100 parts by weight of the liquid oil is 1 Approximately 200 parts by weight, preferably 10 to 150 parts by weight, more preferably 20 to 100 parts by weight, still more preferably 30 to 60 parts by weight.

Emulsion composition of the water present invention comprises water as a base component of the aqueous phase of the emulsion composition. The water content in the emulsified composition of the present invention may be appropriately set according to the emulsified type, form, use, etc. of the emulsified composition, and is, for example, 30 to 95% by weight, preferably 30 to 90% by weight. More preferably, it is 30 to 80% by weight, and further preferably 30 to 75% by weight.

Further, since the emulsified composition of the present invention has excellent emulsification stability that suppresses separation after storage, it is excellent even when it contains a large amount of water, which is inherently more likely to cause aqueous phase separation. It becomes possible to obtain emulsion stability. In view of such effects of the present invention, a preferred embodiment of the emulsified composition of the present invention is an emulsified composition having a relatively high water content. More specifically, preferred examples of the water content in the emulsified composition of the present invention include 50 to 90% by weight, preferably 60 to 80% by weight, and more preferably 65 to 75% by weight.

Surfactants The surfactants are not particularly limited as long as they are pharmaceutically or cosmetically acceptable, and are, for example, nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Examples include surfactants. Among these surfactants, a nonionic surfactant is preferable from the viewpoint of obtaining more excellent emulsion stability.

Specific examples of the nonionic surfactant include polyoxyethylene hydrogenated castor oil; sorbitan fatty acid esters (eg, sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan mono). Stearate, sorbitan sesquioleate, sorbitan trioleate, penta-2-ethylhexylate diglycerol sorbitan, tetra-2-ethylhexylate diglycerol sorbitan, etc.); glycerin fatty acid esters (eg, monocotton seed oil fatty acid glyceryl, monoerucate glyceryl, Glyceryl sesquioleate, glyceryl monostearate (glycerin stearate), α, α'-glyceryl pyroglutamate oleate, glycerin malate monostearate, etc.); propylene glycol fatty acid esters (eg, propylene glycol monostearate, etc.) Glycerin alkyl ether; stearic acid-2; polyoxyethylene sorbitan fatty acid esters (eg, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tetraoleate, etc.); polyoxyethylene sorbit fatty acid Esters (eg, polyoxyethylene sorbit monolaurate, polyoxyethylene sorbit monooleate, polyoxyethylene sorbit pentaoleate, polyoxyethylene sorbit monostearate, etc.); polyoxyethylene glycerin fatty acid esters (eg, poly) Oxyethylene glycerin monostearate, polyoxyethylene glycerin monoisostearate, polyoxyethylene glycerin triisostearate, etc.); Polyoxyethylene fatty acid esters (eg, polyoxyethylene monooleate, polyoxyethylene monostearate, etc.) (Polyoxyl stearate), polyoxyethylene distearate, polyoxyethylene monodiolate, ethylene glycol distearate, etc.); Polyoxyethylene alkyl ethers (eg, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxy) Ethethylene stearyl ether, polyoxyethylene behenyl ether, polyoxyethylene 2-octyldodecyl ether, polyoxyethylene cholestanol ether, etc.); Pluronic type (eg) For example, Pluronic, etc.); Polyoxyethylene / polyoxypropylene alkyl ethers (for example, polyoxyethylene / polyoxypropylene-cetyl ether, polyoxyethylene / polyoxypropylene-2-decyltetradecyl ether, polyoxyethylene / poly) Oxypropylene monobutyl ether, polyoxyethylene / polyoxypropylene hydrogenated lanolin, polyoxyethylene / polyoxypropylene glycerin ether, etc.); steerless-21 and the like.

Among these nonionic surfactants, polyoxyethylene hydrogenated castor oil, glycerin polyglycerin fatty acids, and polyoxyethylene fatty acid esters are preferably mentioned, and more preferably, from the viewpoint of obtaining more excellent emulsion stability. Examples thereof include polyoxyethylene hydrogenated castor oil, glyceryl monostearate (glycerin stearate), and polyoxyethylene monostearate (polyoxyl stearate).

These surfactants may be used alone or in combination of two or more.

In the emulsified composition of the present invention, the content of the surfactant may be appropriately set according to the type of the surfactant to be used, for example, 0.5 to 7% by weight, preferably 1 to 5% by weight. %, More preferably 2 to 5% by weight, still more preferably 3 to 5% by weight.

Other Ingredients In addition to the above-mentioned ingredients, the emulsified composition of the present invention may contain other commonly used additives, if necessary. Such additives include, for example, polyhydric alcohols, thickeners, pH regulators, buffers, solubilizers, chelating agents, preservatives, preservatives, antioxidants, stabilizers, fragrances, colorants. And so on.

The polyhydric alcohol is not particularly limited as long as it is pharmaceutically or cosmetically acceptable, and examples thereof include propylene glycol, 1,3-butylene glycol (BG), ethylene glycol, isoprene glycol, diethylene glycol, and diethylene glycol. Dihydric alcohols such as propylene glycol; trihydric alcohols such as glycerin, polyethylene glycols such as Macrogol 4000 and Macrogol 6000, and the like can be mentioned. These polyhydric alcohols may be used alone or in combination of two or more. Among these polyhydric alcohols, from the viewpoint of obtaining more excellent emulsion stability, dihydric alcohols and trihydric alcohols are preferable, and 1,3-butylene glycol (BG) and glycerin are more preferable. When the emulsified composition of the present invention contains a polyhydric alcohol, the content thereof may be appropriately set according to the type of the polyhydric alcohol used, for example, 1 to 20% by weight, preferably 5. -15% by weight, more preferably 7-13% by weight. Further, when glycerin is contained in the emulsified composition of the present invention, the content thereof is, for example, 0.5 to 10% by weight, preferably 1 to 7% by weight, from the viewpoint of obtaining more excellent emulsification stability. Preferably, it is 1 to 5% by weight.

The thickener is preferably blended from the viewpoint of further improving the emulsion stabilizing effect of the emulsion stabilizer of the present invention. The thickener is not particularly limited as long as it is pharmaceutically or cosmetically acceptable, and for example, carboxyvinyl polymer, hypromellose, polyvinylpyrrolidone, sodium alginate, ethyl cellulose, sodium carboxymethyl cellulose, xanthan gum, carrageenan, etc. , And preferably carboxyvinyl polymer, xanthan gum. When a thickener is contained in the emulsified composition containing the emulsion stabilizer of the present invention, the content thereof may be appropriately set according to the type of thickener to be used, but is more excellent. From the viewpoint of obtaining emulsion stability, for example, 0.1 to 2% by weight, preferably 0.1 to 1.8% by weight, more preferably 0.2 to 1.5% by weight, still more preferably 0.4 to 1% by weight, more preferably 0.5 to 0.8% by weight.

Further, the emulsified composition of the present invention may contain, if necessary, a medicinal ingredient capable of exerting a pharmaceutical or cosmetic physiological function in addition to the above-mentioned ingredients. Examples of such medicinal ingredients include steroids (dexamethacin, dexamethasone hydrochloride, dexamethacin acetate, hydrocortisone hydrochloride, prednisolone salicate, prednisolone acetate, etc.), antihistamines (diphenhydramine, diphenhydramine hydrochloride, chlorhexidine maleate, etc.), and local anesthesia. Agents (lydocaine, dibucaine, procaine, tetracaine, bupivacaine, mepivacaine, chloroprocaine, proparacaine, meprilcaine or salts thereof), alkyl benzoates (eg ethyl aminobenzoate, diethylaminoethyl parabutylaminobenzoate), orthokines, Oxesazein, oxypolyentoxydecane, funnel extract, percaminepase, tesitdecitin, etc.), anti-inflammatory agents (alantine, salicylic acid, glycol salicylate, methyl salicylate, indomethacin, fervinac, diclofenac sodium, sodium loxoprofen, etc.), bactericides (benzalconium chloride, Decalinium chloride, benzethonium chloride, cetylpyridinium chloride, chlorhexidine hydrochloride, chlorhexidine gluconate, aqueous ammonia, sulfaziazine, lactic acid, phenol, etc.), antipruritic agents (crotamiton, thiantolu, etc.), skin protectants (colodione, castor oil, etc.), blood circulation promotion Ingredients (nonyl acid vanillylamide, nicotinic acid benzyl ester, capsaicin, capsicum extract, etc.), vitamins (vitamins A, B, C, D, E, etc.), mucopolysaccharides (sodium chondroitin sulfate, glucosamine, hyaluronic acid, etc.), etc. Can be mentioned. These medicinal ingredients may be used alone or in combination of two or more. In addition, when these medicinal ingredients are contained in the emulsified composition containing the emulsification stabilizer of the present invention, the content thereof should be appropriately set according to the type of the medicinal ingredient used, the expected effect, and the like. Just do it.

Formulation Form / Use The emulsified type of the present invention may be either a water-in-oil type or an oil-in-water type. Since the emulsified composition of the present invention exhibits excellent emulsification stability that suppresses separation after storage, it originally contains a large amount of water such as an oil-in-water type, which is more likely to cause aqueous phase separation. However, it becomes possible to provide excellent emulsification stability. In view of such effects of the present invention, the preferred emulsified type of the emulsified composition of the present invention is the oil-in-water type having a relatively high water content.

The emulsified composition of the present invention can be used as an external preparation for cosmetics, external quasi-drugs, external pharmaceuticals and the like. The product form of the emulsified composition of the present invention is not particularly limited, and examples thereof include creams, ointments, emulsions, gels, oils, lotions, liniments, and aerosols. Among these, creams, ointments, emulsions and lotions are preferable, and creams, emulsions and lotions are more preferable.

Production Method The emulsified composition of the present invention can be produced according to a known emulsified preparation formulation method according to the emulsified type. For example, in the method for producing an emulsified composition of the present invention, the components to be contained are divided into a water-soluble component and an oil-based component, an aqueous phase containing the water-soluble component and an oil phase containing the oil-based component are prepared, and these are prepared. Examples thereof include a method of emulsifying according to a known method.

2. 2. Emulsification Stabilization Method As described above, lidocaine and / or a salt thereof exhibits excellent emulsion stability in an emulsification composition containing ufenamate and isopropylmethylphenol. Therefore, the present invention further comprises (C) lidocaine and / or a salt thereof in an emulsified composition containing (A) ufenamate and (B) isopropylmethylphenol, together with the component (A) and the component (B). Provided is a method for stabilizing emulsion to be blended.

In the emulsification stabilization method of the present invention, emulsification stabilization means suppressing the separation of the emulsified composition after storage. Separation means that the aqueous phase and / or the oil phase are separated from the emulsified composition. A more preferable embodiment of the emulsion stabilization is to suppress the separation of the aqueous phase from the emulsified composition after storage, and a more preferable embodiment is that the emulsified state of the emulsified composition is uniform after storage. That is, the droplets in the emulsion are kept uniformly dispersed in the dispersion medium.

In the case of the above-mentioned "1. Emulsification composition", the type and content of each component used in the emulsion stabilization method of the present invention, the type and content of the component to be blended in the emulsification composition, the formulation form, etc. Is similar to.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto.

The emulsified composition shown in Test Example Table 1 was prepared. Specifically, each component (I) shown in Table 1 is heated and mixed at 65 to 75 ° C. to dissolve the solid content, and then the components (A) to (C) are further mixed and dissolved to obtain an oil phase. , Each component of (II) shown in Table 1 was heated and mixed at 65 to 75 ° C., an aqueous phase obtained by dissolving the solid content was added, emulsified using a homomixer, and cooled and stirred to 35 ° C. , A creamy oil-in-water emulsified composition was produced.

10 g of each of the obtained emulsified compositions was filled in a glass bottle (screw tube bottle No. 4, capacity 13.5 mL, manufactured by Maruem, transparent), sealed, and stored at 60 ° C. for 3 weeks. Each emulsified composition after storage was visually observed, and the emulsified stability was evaluated based on the following criteria. The results are shown in Table 1.
X: Separation of the aqueous phase is clearly recognized.
Δ: Slight separation of the aqueous phase is observed.
◯: There is a tendency for creaming, but separation is not observed.
⊚: The emulsified state is uniform and separation is not observed.
The creaming tendency means a non-uniform state in an emulsified state, and specifically, a state in which droplets in the produced emulsion are in the process of floating or settling due to the difference in specific gravity with the dispersion medium.

As is clear from Table 1, the emulsified composition containing ufenamate and lidocaine (Comparative Example 1) had a remarkable instability in the emulsified state because the aqueous phase was separated after storage. On the other hand, it was found that excellent emulsion stability was obtained when lidocaine was further added to the emulsified composition containing ufenamate and lidocaine (Examples 1 to 4). This effect of improving the emulsion stability was particularly remarkable in Examples 2 to 4. The emulsified composition prepared in the same manner as in Comparative Example 1 except that it does not contain isopropylmethylphenol, and the emulsified composition prepared in the same manner as in Comparative Example 1 except that it does not contain ufenamate are both water. Separation of the phases was observed and the emulsified state was unstable, but the degree was not as remarkable as in Comparative Example 1.

Formulation Examples The emulsified compositions of the formulations shown in Table 2 were prepared in the same manner as in the above test examples. The emulsified compositions of both formulationss had excellent emulsification stability.

Claims (7)

An emulsified composition containing (A) ufenamate, (B) isopropylmethylphenol, and (C) lidocaine and / or a salt thereof. The emulsified composition according to claim 1, which contains the component (C) in a total amount of 0.1 to 5% by weight. The emulsified composition according to claim 1 or 2, wherein the component (C) is contained in a total amount of 0.005 to 5 parts by weight per part by weight of the component (A). The emulsified composition according to any one of claims 1 to 3, wherein the component (C) is contained in a total amount of 0.03 to 500 parts by weight per part by weight of the component (B). The emulsified composition according to any one of claims 1 to 4, which contains an oil selected from the group consisting of higher alcohols, ester oils, liquid hydrocarbon oils, and silicone oils. The emulsified composition according to any one of claims 1 to 5, which contains a nonionic surfactant selected from the group consisting of glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, and polyethylene glycol fatty acid ester. A method for stabilizing an emulsion, wherein (C) lidocaine and / or a salt thereof is blended together with the component (A) and the component (B) in an emulsification composition containing (A) ufenamate and (B) isopropylmethylphenol.