JP6058604B2 - Core shell structure and S / O type suspension containing the same - Google Patents

Description

  The present invention relates to a core-shell structure and an S / O type suspension containing the same.

  A core-shell structure including a core part and a shell part, and an S / O suspension containing the core-shell structure are used in a wide range of applications such as medicine, food, and cosmetics.

  As an example used for uses such as pharmaceuticals, foods, and cosmetics, there is a structure in which a core part containing a drug is wrapped in a shell part, and the pharmacokinetics of the drug is controlled by the action of the shell part. For example, an S / O / W emulsion in which fine S / O particles with suppressed leakage of inclusions are dispersed has been proposed (Patent Document 1). In addition, an S / O-type external preparation that improves the skin permeability of a hydrophilic drug has been proposed (Patent Document 2).

JP 2009-084293 A International Publication No. 2006/025583

  The inventors of the present invention designed a core-shell structure composed of a core part and a shell part containing a compound having a hydrophilic group and a hydrophobic group by original research, and even when trying to actually manufacture this structure, it has been widely used in the past. It has been found that there is a problem that a core-shell structure cannot be manufactured if the configuration of the shell portion is adopted.

  Then, this invention makes it a subject to provide the core-shell structure which contains the compound which has a hydrophilic group and a hydrophobic group in a core part.

The inventors of the present invention have made extensive studies to solve the above problems, and have found that the above problems can be solved by using a shell portion containing a surfactant having a melting point of 30 ° C. or higher. The present invention has been completed through further trial and error based on this finding, and includes the following aspects.
Item 1.
A core shell structure including a core portion and a shell portion,
A core-shell structure in which the core part contains a compound having a hydrophilic group and a hydrophobic group, and the shell part contains a surfactant having a melting point of 30 ° C. or higher.
Item 2.
Item 2. The core-shell structure according to Item 1, wherein the surfactant is a sucrose fatty acid ester.
Item 3.
Item 3. The core-shell structure according to Item 2, wherein the sucrose fatty acid ester is an ester of sucrose and a saturated or unsaturated monovalent fatty acid having 8 to 30 carbon atoms.
Item 4.
Item 3. The core-shell structure according to Item 2, wherein the sucrose fatty acid ester is at least one sucrose fatty acid ester selected from the group consisting of sucrose palmitate, sucrose oleate, and sucrose behenate.
Item 5.
The core-shell structure according to any one of Items 1 to 4, and a base phase,
The base phase contains the core-shell structure;
S / O type suspension.

  ADVANTAGE OF THE INVENTION According to this invention, the core shell structure which contains the compound which has a hydrophilic group and a hydrophobic group in a core part can be provided.

1. Core-shell structure of the present invention In the core- shell structure of the present invention, the core part contains a compound having a hydrophilic group and a hydrophobic group, and the shell part contains a surfactant having a melting point of 30 ° C. or higher.

  More specifically, the core-shell structure of the present invention has a core-shell structure in which the surfactant in the shell part covers a part or the entire surface of the core part.

  The shape and size of the core-shell structure are not particularly limited, but the average size is preferably 2 nm to 10 μm.

In the present invention, the average size of the core-shell structure is a number average diameter calculated by a dynamic light scattering method during solvent dispersion.
1.1 The compound having a core part hydrophilic group and a hydrophobic group is not particularly limited.

  Although not particularly bound by theory, a compound having a hydrophilic group and a hydrophobic group can exhibit an action as a surfactant. In the production process of the core-shell structure, the compound having a hydrophilic group and a hydrophobic group should be placed in the core part, and it is the same as the surfactant in the shell part due to its properties as a surfactant. In this case, the arrangement in the core portion may not be successful, and as a result, it may be difficult to manufacture the core-shell structure.

The compound having a hydrophilic group and a hydrophobic group is typically a compound having at least one of the following characteristics (1) to (3):
(1) The molecular weight is 100 to 10,000.
(2) Water solubility is 1% to 100%.
(3) HLB value is 0-7 or 10-20.

  In the above, molecular weight becomes like this. Preferably it is 100-5000, More preferably, it is 100-1000.

  In the above, the water solubility is preferably 5% to 50%, more preferably 10% to 50%.

  In the above, the HLB value is preferably 0 to 5, and more preferably 0 to 3.

  In the present invention, the water solubility is a value based on the EPA method (EPA Chemical Fate Testing Guideline CG-1500 “Water Solubility”).

  Specific examples of the compound having a hydrophilic group and a hydrophobic group are not particularly limited, and examples thereof include montelukast, benzalkonium chloride, dehydrocholic acid, polidocanol and the like in the case of a drug.

  In addition, when the compound having a hydrophilic group and a hydrophobic group is a drug, the above-described pharmacologically acceptable salt can also be used as the compound.

  Other specific examples of the compound having a hydrophilic group and a hydrophobic group include, for example, curing agents and / or curing accelerators, foaming agents, adhesives, inks, cosmetics, and fragrances.

  The amount of the compound having a hydrophilic group and a hydrophobic group contained in the core-shell structure can be, for example, 1 to 30% by weight, depending on the characteristics of the compound.

  The core portion may contain two or more compounds having a hydrophilic group and a hydrophobic group as necessary.

  Although not particularly limited, the core part typically contains a compound having a hydrophilic group and a hydrophobic group as an active ingredient. In this case, the core part may further contain a compound having only one of a hydrophilic group and a hydrophobic group and / or a compound having neither of these as another active ingredient, if necessary. .

  The core part may further contain at least one other component in addition to the compound having a hydrophilic group and a hydrophobic group. Examples of other components include, but are not limited to, stabilizers, preservatives, transdermal absorption accelerators, skin irritation reducing agents, curing agents, curing accelerators, and foaming agents, depending on the purpose of use. .

  The stabilizer has a function of stabilizing the core-shell structure, prevents unintended early collapse of the core-shell structure, and ensures the sustained release effect of the compound having a hydrophilic group and a hydrophobic group.

  The stabilizer is not particularly limited, and specific examples include polysaccharides, proteins, and hydrophilic polymer materials. The content of the stabilizer in the core portion can be appropriately set depending on the type of the stabilizer. For example, the weight ratio of the compound having a hydrophilic group and a hydrophobic group to the stabilizer is from 1: 0.1 to 1. : It can also mix | blend so that it may be set to 10.

  The preservative is not particularly limited, and specific examples include methyl paraoxybenzoate, propyl paraoxybenzoate, phenoxyethanol and thymol. Although the content rate in the core part of an antiseptic | preservative can be set suitably also with the kind, For example, it can also mix | blend so that it may become 0.01%-10%. An antiseptic | preservative may contain 1 type (s) or 2 or more types.

  Although it does not specifically limit as a percutaneous absorption enhancer, Specifically, higher alcohol, N-acyl sarcosine and its salt, higher monocarboxylic acid, higher monocarboxylic acid ester, aromatic monoterpene fatty acid ester, carbon number 2 To 10 divalent carboxylic acids and salts thereof, polyoxyethylene alkyl ether phosphates and salts thereof, lactic acid, lactic acid esters, and citric acid. The percutaneous absorption enhancer may contain one kind or two or more kinds. The content of the percutaneous absorption enhancer in the core can be appropriately set depending on the type of the percutaneous absorption enhancer. For example, the weight ratio of the compound having a hydrophilic group and a hydrophobic group to the transdermal absorption enhancer is 1: 0. .01 to 1:50 can also be blended.

  The skin irritation reducing agent is not particularly limited. Specifically, hydroquinone glycoside, pantethine, tranexamic acid, lecithin, titanium oxide, aluminum hydroxide, sodium nitrite, sodium hydrogen nitrite, soybean lecithin, methionine, Examples include glycyrrhetinic acid, BHT, BHA, vitamin E and derivatives thereof, vitamin C and derivatives thereof, benzotriazole, propyl gallate, and mercaptobenzimidazole. The skin irritation reducing agent may contain one kind or two or more kinds. Although the content rate in the core part of a skin irritation reducing agent can be suitably set according to the kind, it can also mix | blend, for example so that it may be 0.1%-50%.

1.2 Shell Part The shell part contains a surfactant having a melting point of 30 ° C. or higher.

  The surfactant is not particularly limited as long as it can form a shell part having a core-shell structure.

  The shell portion may use a plurality of types of surfactants in combination. At this time, the shell portion may contain only a plurality of surfactants having a melting point of 30 ° C. or higher as the surfactant, or an interface having a melting point of less than 30 ° C. in addition to the surfactant having a melting point of 30 ° C. or higher. One or more activators may be included.

  When the shell portion contains a surfactant having a melting point of 30 ° C. or higher and a surfactant having a melting point of less than 30 ° C., the former ratio is 0.5 wt% to 20 wt% with respect to the total amount of the surfactant. %, Preferably 1 to 10% by weight.

  Although not particularly limited, when producing a core-shell structure, as described later, when using a solution in which a shell part component containing a surfactant is dissolved in a solvent such as cyclohexane, hexane, or toluene, the shell part component is used. However, if a surfactant having a melting point of less than 30 ° C. is further contained in addition to the surfactant having a melting point of 30 ° C. or higher, it is advantageous because the surfactant is easily dissolved in the solvent.

  The surfactant having a melting point of 30 ° C. or higher is not particularly limited, and specific examples include sucrose fatty acid esters.

  Although it does not specifically limit as said sucrose fatty acid ester, Preferably ester with sucrose and a C8-C30 saturated or unsaturated monovalent fatty acid is mentioned.

  Although it does not specifically limit as a specific example of the said sucrose fatty acid ester, Preferably sucrose palmitic acid ester, sucrose oleic acid ester, sucrose behenic acid ester, etc. are mentioned.

  A plurality of sucrose fatty acid esters may be used in combination as the sucrose fatty acid ester.

  The surfactant having a melting point of 30 ° C. or higher is not particularly limited, but those having an HLB value of preferably 7 or less, more preferably 5 or less can be used.

  The blending amount of the total amount of the surfactant can be appropriately set within the range in which the effect of the present invention is exerted. For example, the weight ratio with the compound having a hydrophilic group and a hydrophobic group contained in the core part Can be 1: 5 to 1: 100.

  The shell portion may further contain at least one other component in addition to the surfactant. Examples of other components include, but are not limited to, stabilizers, preservatives, skin irritation reducing agents, analgesics, percutaneous absorption enhancers, dispersants, viscosity adjusting agents, and the like, depending on the purpose of use. .

  The stabilizer acts to stabilize the core-shell structure, prevents unintended early collapse of the core-shell structure, and further ensures the sustained release effect of the components contained in the core part as necessary. Have.

  The stabilizer is not particularly limited, and specifically, fatty acids and salts thereof, parahydroxybenzoates such as methylparaben and propylparapen, alcohols such as chlorobutanol, pendyl alcohol, and phenylethyl alcohol, thimerosal , Acetic anhydride, sorbic acid, sodium bisulfite, L-ascorbic acid, sodium ascorbate, butylhydroxyanisole, butylhydroxytoluene, propyl gallate, tocopherol acetate, dl-α-tocopherol, protein and polysaccharides. A stabilizer may contain 1 type, or 2 or more types. The content of the stabilizer in the shell portion can be appropriately set depending on the type of the stabilizer, but for example, the weight ratio of the total amount of the surfactant and the stabilizer is 1: 0.01 to 1:50. It can also be blended.

  The preservative is not particularly limited, and specific examples include methyl paraoxybenzoate, propyl paraoxybenzoate, phenoxyethanol and thymol. An antiseptic | preservative may contain 1 type (s) or 2 or more types. Although the content rate in the shell part of an antiseptic | preservative can be suitably set according to the kind, it can also mix | blend, for example so that it may become 0.01%-10%.

  The skin irritation reducing agent is not particularly limited. Specifically, hydroquinone glycoside, pantethine, tranexamic acid, lecithin, titanium oxide, aluminum hydroxide, sodium nitrite, sodium hydrogen nitrite, soybean lecithin, methionine, Examples include glycyrrhetinic acid, BHT, BHA, vitamin E and derivatives thereof, vitamin C and derivatives thereof, benzotriazole, propyl gallate, and mercaptobenzimidazole. The skin irritation reducing agent may contain one kind or two or more kinds. Although the content rate in the shell part of a skin irritation reducing agent can be suitably set according to the kind, it can also mix | blend, for example so that it may be 0.1%-50%.

  Although it does not specifically limit as an analgesic, Specifically, local anesthetics, such as procaine, tetracaine, lidocaine, dibucaine, and prilocaine, its salt, etc. are mentioned. An analgesic may contain 1 type (s) or 2 or more types. Although the content rate in the shell part of an analgesic can be suitably set according to the kind, it can also mix | blend so that it may be 0.1%-30%, for example.

  Although it does not specifically limit as a percutaneous absorption enhancer, Specifically, higher alcohol, N-acyl sarcosine and its salt, higher monocarboxylic acid, higher monocarboxylic acid ester, aromatic monoterpene fatty acid ester, carbon number 2 To 10 divalent carboxylic acids and salts thereof, polyoxyethylene alkyl ether phosphates and salts thereof, lactic acid, lactic acid esters, and citric acid. The percutaneous absorption enhancer may contain one kind or two or more kinds. Although the content rate in the shell part of a percutaneous absorption enhancer can be suitably set according to the kind, it can also mix | blend so that it may be set to 0.1%-30%, for example.

2. S / O type suspension of the present invention The S / O type suspension of the present invention contains a base phase,
The base phase contains the core-shell structure;
This is an S / O type suspension.

2.1 Base Phase The base phase is a phase containing a base, and in the S / O suspension, the core shell structure is dispersed or dissolved in the base phase.

  The base can be appropriately selected from those suitable for dispersing or dissolving the core-shell structure according to the purpose of use and the like, and is not particularly limited.

  A plurality of types of bases may be used in combination.

  The base is not particularly limited. For example, vegetable oils, animal oils, neutral lipids, synthetic fats and oils, sterol derivatives, waxes, hydrocarbons, monoalcohol carboxylates, oxyacid esters, polyhydric alcohol fatty acid esters , Silicones, higher (polyhydric) alcohols, higher fatty acids and fluorinated oils.

  The vegetable oil is not particularly limited, and examples thereof include soybean oil, sesame oil, olive oil, palm oil, balm oil, rice bran oil, cottonseed oil, sunflower oil, rice bran oil, cacao butter, corn oil, bean flower oil and rapeseed oil. .

  Although it does not specifically limit as animal oil, For example, mink oil, turtle oil, fish oil, cow oil, horse oil, pig oil, shark squalane, etc. are mentioned.

  The neutral lipid is not particularly limited, and examples thereof include triolein, trilinolein, trimyristin, tristearin, and triarachidonin.

  Although it does not specifically limit as synthetic fats and oils, For example, a phospholipid, an azone, etc. are mentioned.

  The sterol derivative is not particularly limited, and examples thereof include dihydrocholesterol, lanosterol, dihydrolanosterol, phytosterol, cholic acid, and cholesteryl linoleate.

  Examples of waxes include candelilla wax, carnauba wax, rice wax, beeswax, beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, petrolatum, Fischer-Tropsch wax, polyethylene wax, and ethylene / propylene copolymer. Can be mentioned.

  Examples of hydrocarbons include liquid paraffin (mineral oil), heavy liquid isoparaffin, light liquid isoparaffin, α-olefin oligomer, polyisobutene, hydrogenated polyisobutene, polybutene, squalane, olive-derived squalane, squalene, petrolatum and solid paraffin. It is done.

  Examples of monoalcohol carboxylic acid esters include octyldodecyl myristate, hexyldecyl myristate, octyldodecyl isostearate, cetyl palmitate, octyldodecyl palmitate, cetyl octoate, hexyldecyl octoate, isotridecyl isononanoate, isononanoyl isononanoate, Octyl isononanoate, isotridecyl isononanoate, isodecyl neopentanoate, isotridecyl neopentanoate, isostearyl neopentanoate, octyldodecyl neodecanoate, oleyl oleate, octyl dodecyl oleate, octyldodecyl ricinoleate, octyldodecyl lanolinate, hexyldecyl dimethyloctanoate , Octyldodecyl erucate, isostearic acid hydrogenated castor oil, ethyl oleate Avocado oil fatty acid ethyl, isopropyl myristate, isopropyl palmitate, octyl palmitate, isopropyl isostearate, isopropyl lanolin fatty acid, diethyl sebacate, diisopropyl sebacate, dioctyl sebacate, diisopropyl adipate, dibutyloctyl sebacate, diisobutyl adipate, Examples include dioctyl succinate and triethyl citrate.

  Examples of oxyesters include cetyl lactate, diisostearyl malate, and hydrogenated castor oil monoisostearate.

  Polyhydric alcohol fatty acid esters include glyceryl trioctanoate, glyceryl trioleate, glyceryl triisostearate, glyceryl diisostearate, glyceryl tri (caprylic acid / capric acid), tri (caprylic acid / capric acid / myristic acid / stearic acid) ) Glyceryl, hydrogenated rosin triglyceride (hydrogenated ester gum), rosin triglyceride (ester gum), glyceryl behenate, trimethylolpropane trioctanoate, trimethylolpropane triisostearate, neopentylglycol dioctanoate, neopentyl glycol dicaprate Pentyl glycol, 2-butyl-2-ethyl-1,3-propanediol dioctanoate, propylene glycol dioleate, pentaerythrtetraoctanoate Chill, hydrogenated rosin pentaerythrityl, triethylhexanoic acid ditrimethylolpropane, (isostearic acid / sebacic acid) ditrimethylolpropane, triethylhexanoic acid pentaerythrityl, (hydroxystearic acid / stearic acid / rosinic acid) dipentaerythrityl, diisostearic acid di Glyceryl, polyglyceryl tetraisostearate, polyglyceryl-10 nonaisostearate, deca (erucic acid / isostearic acid / ricinoleic acid) polyglyceryl-8, (hexyldecanoic acid / sebacic acid) diglyceryl oligoester, glycol distearate (ethylene glycol distearate) Dineopentanoic acid 3-methyl-1,5-pentanediol and dineopentanoic acid 2,4-diethyl-1,5-penta Diol, and the like.

  Silicones include dimethicone (dimethylpolysiloxane), highly polymerized dimethicone (highly polymerized dimethylpolysiloxane), cyclomethicone (cyclic dimethylsiloxane, decamethylcyclopentasiloxane), phenyltrimethicone, diphenyldimethicone, phenyldimethicone, stearoxypropyl. Dimethylamine, (aminoethylaminopropylmethicone / dimethicone) copolymer, dimethiconol, dimethiconol crosspolymer, silicone resin, silicone rubber, amino-modified silicone such as aminopropyldimethicone or amodimethicone, cation-modified silicone, polyether modified such as dimethicone copolyol Silicone, polyglycerin modified silicone, sugar modified silicone, carboxylic acid modified silicone, phosphoric acid modified silicone Sulfuric acid modified silicone, alkyl modified silicone, fatty acid modified silicone, alkyl ether modified silicone, amino acid modified silicone, peptide modified silicone, fluorine modified silicone, cationic modified or polyether modified silicone, amino modified or polyether modified silicone, alkyl modified or polyether Examples thereof include modified silicones and polysiloxane / oxyalkylene copolymers.

  Higher (polyhydric) alcohols include cetanol, myristyl alcohol, oleyl alcohol, lauryl alcohol, cetostearyl alcohol, stearyl alcohol, aralkyl alcohol, behenyl alcohol, jojoba alcohol, chimyl alcohol, seraalkyl alcohol, batyl alcohol, hexyl decanol, Examples include isostearyl alcohol, 2-octyldodecanol, and dimer diol.

  Higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, undecylenic acid, 12-hydroxystearic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, docosahexaenoic acid Eicosapentaenoic acid, isohexadecanoic acid, anteisohenicosanoic acid, long-chain branched fatty acid, dimer acid and hydrogenated dimer acid.

  Examples of the fluorinated oils include perfluorodecane, perfluorooctane and perfluoropolyether.

  Other bases are not particularly limited, and examples include bases used in ointments, creams, aerosols, tapes, patches, poultices, gels, microneedles, and the like.

2.2 Other Additive Components The S / O suspension of the present invention may contain other additive components depending on the dosage form, purpose of use, and the like.

  The additive component is not particularly limited, but depending on the purpose of use, excipient, colorant, lubricant, binder, emulsifier, thickener, wetting agent, stabilizer, preservative, solvent, solubilizer , Suspending agent, buffering agent, pH adjusting agent, gelling agent, pressure-sensitive adhesive, antioxidant, transdermal absorption enhancer, irritation relaxation agent, preservative, chelating agent, dispersing agent, etc. Can do.

2.3 Manufacturing method of the core-shell structure of the present invention and the S / O type suspension of the present invention The core-shell structure of the present invention and the S / O type suspension of the present invention are not particularly limited. For example, they are manufactured as follows. Can do.

  First, although not particularly limited, the core-shell structure of the present invention can be produced, for example, as follows. The compound having a hydrophilic group and a hydrophobic group and, if desired, the additive component are dissolved in a solvent such as pure water or a phosphate buffer. To this, a solution in which the surfactant and optionally added components are dissolved in a solvent such as cyclohexane, hexane, or toluene is added and stirred with a homogenizer. Thereafter, the core-shell structure of the present invention can be prepared by lyophilization.

2.4 Application of the S / O Type Suspension of the Present Invention The S / O type suspension of the present invention is not particularly limited, but can be used for applications such as external preparations, adhesives, paints, cosmetics and fragrances.

  Although it does not specifically limit as an external preparation, For example, as a tape agent, an ointment, a lotion agent, an aerosol agent, a plaster agent, an aqueous batting agent, a cream agent, a tape agent, a gel agent, an aerosol agent, a patch agent, a microneedle, etc. Can be used.

  Although it does not specifically limit as an adhesive agent, For example, it can use as a thermosetting type adhesive agent, a sealing agent, etc.

  Hereinafter, the present invention will be described in detail by way of examples and test examples, but the present invention is not limited to these examples.

Example 1
Montelukast sodium (0.1 g) is dissolved in 40 g of pure water, and sucrose erucic acid ester (manufactured by Mitsubishi Chemical Foods, ER-290, melting point: 4.0 ° C., HLB2, main components are diester and triester) 1 0.0 g and sucrose stearate (S-070, manufactured by Mitsubishi Chemical Foods Co., Ltd., melting point 61.5 ° C., HLB1 or less, main components are diester and triester) are added to a solution of 80 g of cyclohexane and a homogenizer is added. A homogenizer was stirred (10000 rpm, 2 minutes) at 25 ° C. using a Polytron Corp. PT3100 type. Thereafter, the core-shell structure was prepared by freeze-drying for 2 days using a freeze-drying apparatus (FDU1100, manufactured by Tokyo Rika Kikai Co., Ltd.). 3.0 g of the product was added to 17.0 g of isopropyl myristate to obtain a suspension.

Example 2
A suspension was obtained in the same manner as in Example 1 except that the amount of sucrose erucic acid ester was 2.0 g.

Example 3
A suspension was obtained in the same manner as in Example 1 except that the amount of sucrose erucic acid ester was 2.5 g and the amount of sucrose stearate was 0.5 g.

Example 4
A suspension was obtained in the same manner as in Example 1 except that the amount of sucrose erucic acid ester was 2.75 g and the amount of sucrose stearate was 0.25 g.

Example 5
A suspension was obtained in the same manner as in Example 1 except that the amount of sucrose erucic acid ester was 2.9 g and the amount of sucrose stearate was 0.1 g.

Example 6
A suspension was obtained in the same manner as in Example 5 except that sucrose stearate was changed to S-170 (Mitsubishi Chemical Foods, melting point 65.2 ° C., HLB1, main components were diester and triester).

Comparative Example 1
Montelukast sodium (0.1 g) is dissolved in 40 g of pure water, and sucrose erucic acid ester (manufactured by Mitsubishi Chemical Foods, ER-290, melting point: 4.0 ° C., HLB2, main components are diester and triester) 3 A solution prepared by dissolving 0.0 g in 80 g of cyclohexane was added, and homogenizer stirring (10000 rpm, 2 minutes) was performed at 25 ° C. using a homogenizer (manufactured by Polytron, PT3100 type). Thereafter, it was freeze-dried with a freeze-drying apparatus (FDU1100, manufactured by Tokyo Rika Kikai Co., Ltd.). 3.0 g of the product was added to 17.0 g of isopropyl myristate, but the product dissolved and no suspension was obtained.

Comparative Example 2
Comparative Example 1 except that sucrose erucic acid ester was changed to 5.0 g of sucrose lauric acid ester (manufactured by Mitsubishi Chemical Foods, L-195, melting point 23.9 ° C., HLB2, main components are diester and triester) Similarly, similar results were obtained.

Claims (5)

A core shell structure including a core portion and a shell portion,
A core-shell structure in which the core part contains a compound having a hydrophilic group and a hydrophobic group, and the shell part contains a surfactant having a melting point of 30 ° C. or higher and a surfactant having a melting point of less than 30 ° C. , respectively. The core-shell structure according to claim 1, wherein the surfactant having a melting point of 30 ° C or higher is a sucrose fatty acid ester.   The core-shell structure according to claim 2, wherein the sucrose fatty acid ester is an ester of sucrose and a saturated or unsaturated monovalent fatty acid having 8 to 30 carbon atoms.   The core-shell structure according to claim 2, wherein the sucrose fatty acid ester is at least one sucrose fatty acid ester selected from the group consisting of sucrose palmitate, sucrose oleate, and sucrose behenate. . The core-shell structure according to any one of claims 1 to 4, and a base phase,
The base phase contains the core-shell structure;
S / O type suspension.