KR101036796B1 - Emulsions containing microcapsules and methods of making microcapsules - Google Patents

Abstract

The present invention provides an emulsion comprising the microcapsules and a method for producing an emulsion comprising the microcapsules. Fibroin composition is prepared by adding proteolytic enzymes to an aqueous solution of fibroin containing fibroin and water. After the wax, oil or aliphatic hydrocarbon is added to the fibroin composition to prepare a mixed solution, the mixed solution is stirred to prepare an emulsion including a fine capsule. Emulsions containing microcapsules are biocompatible because they form a shell of the microcapsules using fibroin and can stably preserve wax, oil or aliphatic hydrocarbon components in capsule form for a long time in aqueous solution.

Description

Emulsion and microcapsule manufacturing method comprising a microcapsule {Minute Capsule and Method of manufacturing the same}

The present invention relates to microcapsules and methods of making microcapsules. More particularly, the invention relates to nano or micro sized microcapsules and methods of making nano or micro sized microcapsules.

A microcapsule refers to a capsule having a micro or nano size sealed in a shell with a molecule of liquid, solid or gas as a core. The core material may include a medicine, a perfume, a catalyst, a dye, and the like, and microcapsules are currently used in various industrial fields, and many researches on a manufacturing method thereof have been conducted.

In general, a method of encapsulating a fat-soluble substance is widely used to maintain the fat-soluble substance in a water-soluble environment in a stable and long-term. In particular, when encapsulating a fat-soluble substance in order to distribute the cosmetic component having a fat-soluble property homogeneously in an aqueous solution or the like, not only the fat-soluble substance can be uniformly dispersed in the aqueous solution or the like, but the fat-soluble substance can be preserved without changing its properties for a long time. In order to manufacture the capsule as described above, encapsulation methods using coacervation are generally used.

In general, for the coacervation method, a solution of type type in water was prepared to form an emulsion mainly comprising a capsule having a core of fat soluble component. In preparing an emulsion including the capsule, various components may be used as the shell component. In particular, the capsules used in the pharmaceutical, cosmetics or food sectors should also be biocompatible and the shell component must be able to stably maintain the core component for a certain period of time.

Conventional technologies have been generally used to form the shell mainly using a polymer material, but the polymer materials may be harmful to a living body. Also, when the capsule is micronized to a nano or micro size, a crosslinking agent may be used to stabilize the capsule. Dosing is required, and the crosslinking agent may cause phase separation of the polymer and the fat-soluble component.

Therefore, there is a need for a method of preparing a microcapsule which can maintain the inner core component stably when forming a nano- or micro-sized capsule while being biocompatible.

Accordingly, an object of the present invention is to provide a method for preparing an emulsion comprising a microcapsules capable of maintaining a stable core material while having excellent biocompatibility.

Another object of the present invention is to provide an emulsion comprising a microcapsule capable of maintaining a stable core material while having excellent biocompatibility.

Method for preparing an emulsion comprising a microcapsules according to the embodiments for achieving the above object of the present invention to prepare a fibroin composition by the addition of proteolytic enzymes to the aqueous solution of fibroin containing fibroin and water. After adding a wax, oil, or aliphatic hydrocarbon to the fibroin composition to prepare a mixed solution, the mixed solution may be stirred to prepare an emulsion including a microcapsule.

In embodiments of the present invention, the fibroin composition may include the proteolytic enzyme in a weight ratio of about 12 to 40: 1 with respect to the fibroin.

In embodiments of the present invention, the proteolytic enzyme may be papain, trypsin or chymotrypsin.

In embodiments of the present invention, the preparation of the mixed solution, it may be further added a surfactant.

In embodiments of the present invention, the surfactant may be added in a volume ratio of about 0.3 to about 1.2: 1 relative to the wax, oil or aliphatic hydrocarbon.

In embodiments of the present invention, after the mixed solution is stirred, an acidic substance may be further added.

In embodiments of the present invention, the fibroin aqueous solution may include about 0.5% to about 5% by weight of the fibroin relative to the total weight of the fibroin aqueous solution.

In embodiments of the present invention, the mixed solution may include the fibroin composition with respect to the wax oil or aliphatic hydrocarbon in a volume ratio of 0.05 to about 0.2: 1.

In the emulsion including the microcapsules according to the embodiments for achieving the above object of the present invention, the microcapsules include a wax, oil or aliphatic hydrocarbon core and fibroin shell.

In an embodiment of the present invention, the microcapsules may have a diameter of about 0.3 ㎛ to about 10 ㎛.

In embodiments of the present invention, the emulsion may have a pH of about 2 to about 5.

The emulsion containing the microcapsules according to the present invention described above and the method for producing an emulsion containing the microcapsules are biocompatible because they use fibroin, which is a natural substance obtainable from silk, as a material constituting the shell of the microcapsules. Mars is excellent. In addition, it is easy to manufacture in nano or micro size, it is possible to stably preserve the material contained in the core.

As the inventive concept allows for various changes and numerous modifications, the embodiments will be described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing. The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "consist of" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described on the specification, but one or more other features. It should be understood that they do not exclude in advance the possibility of the presence or addition of numbers, numbers, steps, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, an emulsion including a microcapsule and a method of preparing an emulsion including a microcapsule according to embodiments of the present invention will be described in detail.

Containing microcapsules emulsion  Manufacturing method

1 is a flowchart illustrating a method of preparing an emulsion including a microcapsules according to embodiments of the present invention.

According to the emulsion preparation method including the microcapsules of the present invention, a fibroin composition is prepared by adding proteolytic enzymes to an aqueous solution of fibroin containing fibroin and water (S10). A mixed solution is prepared by adding at least one of wax, oil or hydrophobic aliphatic hydrocarbon to the fibroin composition (S20). The mixture is stirred to prepare an emulsion including a fine capsule (S30).

Referring to FIG. 1, a fibroin composition is prepared by adding proteolytic enzymes to an aqueous solution of fibroin including fibroin and water (S10).

The fibroin serves to form a shell when the microcapsules are manufactured. The fibroin is a kind of silk protein, and the silk protein has a structure in which two strands of fibroin are wrapped in the sericin outer membrane. The fibroin obtained from the silk protein is excellent in biocompatibility such as used as a surgical suture.

The fibroin, when dissolved in water and oil, has low stability and aggregates with each other to form a gel structure. However, the fibroin is dissolved in water and used because aggregation occurs faster in the oil.

According to embodiments of the present invention, the fibroin aqueous solution includes about 0.5 wt% to about 5 wt% fibroin. When the fibroin aqueous solution contains less than about 0.5 wt% of the fibroin, the fibroin may not sufficiently form a shell when the microcapsule is formed. On the other hand, if the fibroin aqueous solution contains less than about 5% by weight of the fibroin, the excess is not used to form the shell of the capsule and is removed in a later process. Thus, the aqueous solution of fibroin comprises from about 0.5% to about 5% by weight fibroin, preferably from about 1% to about 3% by weight fibroin.

The fibroin composition comprises the proteolytic enzyme. When the proteolytic enzyme prevents the aggregation of the fibroin and forms a microcapsule, the proteolytic enzyme may serve to prevent the fibroin from binding to each other to form a structure.

According to embodiments of the present invention, the proteolytic enzyme may be papain, trypsin or chymotrypsin. In general, the fibroin is stable to most proteolytic enzymes, but when contacted with the papain, trypsin or chymotrypsin, the bond between the fibroin molecules is partially broken, thereby decreasing aggregation of the fibroin and binding between the fibroin molecules. Can be.

According to embodiments of the present invention, the fibroin composition comprises the proteolytic enzyme in a weight ratio of about 12 to 40: 1 with respect to the fibroin. When the weight ratio of the proteolytic enzyme to the fibroin is less than about 12, the fibroin may aggregate with each other, and the formed microcapsules may aggregate with each other. If the weight ratio of the proteolytic enzyme to the fibroin exceeds about 40, it is uneconomical when the weight ratio is about 40 and there is no significant difference in the formation of the microcapsules. Therefore, the fibroin composition may include the fibroin and the proteolytic enzyme in a weight ratio of about 1:12 to 40, and preferably may include about 1:22 to 35 weight ratio.

Referring back to Figure 1, by adding a wax, oil or aliphatic hydrocarbon to the fibroin composition to prepare a mixed solution (S20).

The wax, oil or hydrophobic aliphatic hydrocarbons form the core of the microcapsules. When the wax, oil or hydrophobic aliphatic hydrocarbon is added to the hydrophilic fibroin composition as a fat-soluble substance, it does not mix with the fibroin composition and aggregates to form spheres. By coating the fibroin on the surface of the wax, oil or hydrophobic aliphatic hydrocarbon core, it is possible to form the microcapsules.

According to embodiments of the present invention, the fibroin composition and the wax, oil or hydrophobic aliphatic hydrocarbon are mixed at a volume ratio of about 1: 0.05 to 0.2. If the volume ratio of the wax, oil or hydrophobic aliphatic hydrocarbon to the fibroin composition is less than about 0.05, the number of the wax, oil or hydrophobic aliphatic hydrocarbon cores formed in the fibroin composition is too small. When the volume ratio of the wax, oil or hydrophobic aliphatic hydrocarbon to the fibroin composition exceeds about 0.2, separation of the fat-soluble component and the water-soluble component may occur without dispersing the wax, oil or hydrophobic aliphatic hydrocarbon in the fibroin composition. . Therefore, the mixed solution may include the fibroin composition and the wax, oil or hydrophobic aliphatic hydrocarbon in a volume ratio of about 1: 0.05 to about 0.2, preferably in a volume ratio of about 1: 0.1 to about 0.15.

The type of wax, oil or hydrophobic aliphatic hydrocarbon is not particularly limited as long as it is a fat-soluble material that is not mixed with water. The wax can be either natural wax or synthetic wax, and can be either vegetable wax or animal wax. The oil may also be mineral oil, vegetable oil, animal oil or various synthetic oils. In addition, the aliphatic hydrocarbon is not particularly limited in kind, and may use alkanes, alkenes, or alkynes. For example, the oil may be a polyalcohol ester oil, almond oil, apricot seed oil, avocado oil, theobroma oil, carrot seed oil, castor oil, citrus seed oil, coconut oil, corn oil, cottonseed oil, cucumber oil, egg oil, Jojoba oil, lanolin oil, linseed oil, mineral oil, mink oil, olive oil, palm oil, peach seed oil, peanut oil, rape seed oil, safflower oil, sesame oil, shark liver oil, soybean oil, sunflower seed oil, almond oil, whale oil, squalene Or wheat germ oil. The aliphatic hydrocarbon may include octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane or octadecane.

According to embodiments of the present invention, a surfactant may be further added to the mixed solution. The surfactant may serve to stably maintain the wax, oil or aliphatic hydrocarbon core in the hydrophilic fibroin composition without layer separation. When the surfactant is added, the number of the wax, oil or aliphatic hydrocarbon cores produced may be lower, but the wax, oil or aliphatic hydrocarbon cores formed remain dispersed in the fibroin composition for a longer time. Can be.

According to embodiments of the present invention, the surfactant may be added in a volume ratio of about 0.3 to 1.2: 1 relative to the wax, oil or aliphatic hydrocarbon. If the volume ratio of the surfactant to the wax, oil or aliphatic hydrocarbon is less than about 0.3 part by weight, layer separation may occur more rapidly with the fibroin composition than the wax, oil or aliphatic hydrocarbon than without the surfactant. have. That is, when the volume ratio of the surfactant to the wax, oil or aliphatic hydrocarbon is less than about 0.3 part by weight, both the stability and the production yield of the microcapsules may be lowered than when the surfactant is not added. When the volume ratio of the surfactant to the wax, oil or aliphatic hydrocarbon exceeds about 1.2, the capsule yield may be lowered. Therefore, the surfactant may be added in a volume ratio of about 0.3 to 1.2: 1 with respect to the wax, oil or aliphatic hydrocarbon, and preferably in a volume ratio of about 0.5 to 1: 1.

The type of the surfactant may be used a surfactant commonly used in the art, preferably a surfactant may be used. For example, the nonionic surfactant may be polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenol ether, polyoxyalkylene aryl phenol ether, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, poly Oxyalkylene alkyl amines, sorbitan fatty acid esters, alkyl alcohol amines or aryl alcohol amines and the like.

Referring back to Figure 1, the mixed solution is stirred (S30). By stirring the mixed solution, the wax, oil or aliphatic hydrocarbon core may be evenly dispersed in the fibroin composition to increase the efficiency of forming the microcapsules.

According to embodiments of the present invention, the mixed solution may be stirred for about 20 minutes to about 130 minutes at about 400 rpm to about 800 rpm. If the stirring time is less than 20 minutes, the fibroin may not sufficiently coat the wax, oil or aliphatic hydrocarbon core. In addition, if the stirring time exceeds about 130 minutes, there is no significant difference compared to the stirring for 130 minutes.

According to embodiments of the present invention, after stirring the mixed solution, an acidic substance may be further added. After stirring, the mixture has a pH of about 5.5 to about 6. The acidic material may be added until the pH of the emulsion is about 2 to about 5. By adding the acidic substance to adjust the pH of the emulsion to the above range, it is possible to increase the stability of the emulsion. If the pH of the emulsion is less than about 2, the yield of the resulting microcapsules may be lowered. On the other hand, when the pH of the emulsion exceeds about 5, the stability of the microcapsules decreases, and the oil-soluble component and the water-soluble component may easily cause layer separation. Thus, the pH of the emulsion may be about 2 to about 5, preferably about 3.5 to about 4.5.

According to embodiments of the present invention, the acidic material may be hydrochloric acid, acetic acid or phosphoric acid.

The method for preparing an emulsion comprising the microcapsules according to the present invention is a microcapsule comprising the wax, oil or aliphatic hydrocarbon component as a core by adding and stirring a wax, oil or aliphatic hydrocarbon component to a fibroin composition comprising water and fibroin. Emulsions can be prepared easily. In addition, the microcapsules prepared by the method can be usefully used in food or medicine by stably protecting the wax, oil or aliphatic hydrocarbon and coating the wax, oil or aliphatic hydrocarbon core with the biocompatible fibroin. Can be.

Containing microcapsules emulsion

In an emulsion comprising the microcapsules of the present invention, the microcapsules comprise a wax, oil or hydrophobic aliphatic hydrocarbon core and a fibroin shell. As described above, the wax, oil or aliphatic hydrocarbon contained in the microcapsules of the present invention is not particularly limited in kind. For example, the oil may be mineral oil, vegetable oil, animal oil or various synthetic oils. For example, polyalcohol ester oils, almond oil, apricot seed oil, avocado oil, theobroma oil, carrot seed oil, castor oil, citrus seed oil, coconut oil, corn oil, cottonseed oil, cucumber oil, egg oil, jojoba oil, Lanolin oil, linseed oil, mineral oil, mink oil, olive oil, palm oil, peach seed oil, peanut oil, rape seed oil, safflower oil, sesame oil, shark liver oil, soybean oil, sunflower seed oil, almond oil, whale oil, squalene and or embryos Can be Yu etc. The aliphatic hydrocarbons include octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane or octadecane.

The microcapsules of the present invention comprise a fibroin shell. The fibroin is attached to the surface of the wax, oil or aliphatic hydrocarbon to form a shell. Thus, the wax, oil or aliphatic hydrocarbon corresponding to the core of the microcapsules by the fibroin can be stably preserved for a long period of time without changing the ingredients.

According to embodiments of the present invention, the microcapsules may have a diameter of about 0.3 μm to about 10 μm. When forming the fibroin shell on the wax, oil or aliphatic hydrocarbon core, it is easy to prepare a microcapsules having a size of nano to micro.

Hereinafter, the present invention will be described in more detail with reference to Synthesis Examples, Examples and Comparative Examples. However, the following examples are provided to illustrate the present invention, and the present invention is not limited to the following examples and may be variously modified and changed.

Example  One

Fibroin composition was prepared by adding about 4.4 g of papain (Sigma-Aldrich Chemicals, USA) to about 10 g of an aqueous fibroin solution containing about 0.2 g of fibroin (Fineco Co. Ltd., Korea). At about 60 ° C., about 0.5 mL of Span 80 (Sigma-Aldrich Chemicals, USA) was mixed with about 1 mL of wax (Lee Hyun Chemical), and then added to the fibroin composition to prepare a mixed solution. The mixture was stirred at about 600 rpm for about 120 minutes to prepare an emulsion. 1N of HCl was added until the pH of the emulsion was about 4.2, and then stirred at about 600 rpm at room temperature for about 120 minutes to prepare an emulsion including a fine capsule of a wax core-fibroin shell.

Example 2

An emulsion comprising a microcapsule of wax core-fibroin shell was prepared in a manner substantially similar to Example 1 except that about 6.6 g of papain was used.

Example 3

An emulsion comprising a microcapsule of wax core-fibroin shell was prepared in substantially the same manner as in Example 1 except that about 1.5 mL of the wax was used and the Span 80 was not added.

Example 4

An emulsion comprising a microcapsule of wax core-fibroin shell was prepared in substantially the same manner as in Example 1 except that 0.75 mL of the wax and about 0.75 mL of Span 80 were used.

Example 5

An emulsion comprising a wax core and fibroin shell microcapsules was prepared in substantially the same manner as in Example 1 except that the pH of the emulsion was adjusted to about 2.

Comparative Example 1

The emulsion was prepared in substantially the same manner as in Example 1 except that papain was not added.

Comparative Example 2

The emulsion was prepared in substantially the same manner as in Example 1 except that about 2.2 g of papain was used.

Comparative Example 3

An emulsion was prepared in substantially the same manner as in Example 1, except that 1.5 mL of the wax and about 0.015 mL of the Span 80 were used.

Comparative Example 4

An emulsion was prepared in substantially the same manner as in Example 1, except that 1.5 mL of the wax and about 0.15 mL of the Span 80 were used.

Comparative Example 5

The emulsion was prepared in substantially the same manner as in Example 1 except that the pH was adjusted to about 8.

Comparative example  6

The emulsion was prepared in substantially the same manner as in Example 1 except that the pH was adjusted to about 10.

The content of each component used in the preparation of the compositions of the Examples and Comparative Examples is shown in Table 1 below.

Experimental Example  One

The structure of the microcapsules formed in the emulsion for the emulsions of Examples 1, 2, Comparative Example 1 and Comparative 2 was observed by Fourier transform infrared (FT-IR) spectroscopy (EXCALIBER Series, Bio-Rad, USA). The results are shown in FIGS. 2 to 5 below.

As can be seen in Figures 2 and 3, in the case of Example 1 and Example 2, each capsule is formed separately, and the fine capsule of the wax core-fibroin shell is well dispersed in the water It can be seen that. On the other hand, in the case of Comparative Example 1 of FIG. 4 without adding the papain, not only the capsule was not well formed, but also occasionally formed capsules aggregated with each other to form a structure. In addition, in the case of Comparative Example 2 of FIG. 5, although the separated capsules were somewhat observed as compared with Comparative Example 1, the capsules were still aggregated with each other. Therefore, when the proteolytic enzyme such as papain is added about 12 times or more, it can be seen that isolated microcapsules can be prepared.

Experimental Example 2

In Examples 1, 4, 5 and Comparative Examples 3 to 6, the yield of the capsules according to the content of the nonionic surfactant and the pH of the composition and the stability of the capsules were investigated. 6 and 7. Formation yield of the capsule was measured by using the Bradford assay kit (bradford assay kit, BIO-RAD, USA) for the amount of fibroin that did not form a capsule, the weight of the added fibroin The yield of forming the capsule was evaluated by the weight ratio of fibroin used to form the capsule. Meanwhile, the stability of the emulsion was evaluated by measuring the time taken for the wax, which is the core component of the emulsion, to exit the microcapsules and form a layer on the emulsion.

As can be seen in FIG. 6 of the actual capsule produced, when the nonionic surfactant Span 80 is used to form the microcapsules, the yield of the microcapsules is obtained when the nonionic surfactant is not used. It decreased compared with. However, when the volume ratio of the nonionic surfactant to the wax is about 0.3 or more, it can be seen that the microcapsules are stably dispersed for a longer period of time than when not added. In particular, when the volume ratio of the nonionic surfactant and the wax is 1, the stability of the microcapsules is increased by about two times or more compared with the case where the nonionic surfactant is not added.

Looking at Figure 7, it can be seen that the change in the yield of the microcapsules according to the pH is not large, but the stability is sharply lowered when the pH of the emulsion is about 6 or more.

Experimental Example 3

The wax core-fibroin shell microcapsules of the emulsion of Example 1 were examined for particle size distribution using a particle size analyzer, and the results are shown in FIG. 8. Ultrasonic dispersion treatment was performed to specify the size of the dispersed single particles before examining the particle size distribution using the particle size analyzer. As can be seen in the graph of FIG. 8, it can be seen that about 80% of the microcapsules have a diameter of about 0.5 μm to about 3.8 μm. Therefore, it was found that the emulsion of Example 1 contained uniform microcapsules of nano or micro size.

The emulsion comprising the microcapsules prepared according to the method of the present invention described above is excellent in biocompatibility because the shell of the microcapsules is formed using fibroin. In addition, since the microcapsules are disintegrated in the aqueous solution or separated from the fat-soluble component and the water-soluble component for a long time, the wax, oil or aliphatic hydrocarbon component used as the core component can be stably preserved. Therefore, the emulsion including the microcapsules prepared by the above method can be used to stably protect and maintain the components useful in many fields, such as medicine, pesticides or cosmetics.

As described above with reference to the preferred embodiment of the present invention, those skilled in the art without departing from the spirit and scope of the present invention described in the claims below various modifications and It will be appreciated that it can be changed.

1 is a flow chart showing a process for preparing an emulsion comprising a microcapsules according to embodiments of the present invention.

2 to 5 are photographs showing the observation of the microcapsules contained in the emulsion including the microcapsules according to embodiments of the present invention by Fourier transform infrared (FT-IR) spectroscopy.

FIG. 6 is a graph illustrating the yield of the microcapsules and the stability of the microcapsules according to the content of the nonionic surfactant in the wax in the method of preparing an emulsion including the microcapsules according to embodiments of the present invention. to be.

FIG. 7 is a graph illustrating the yield of the microcapsules and the stability of the microcapsules according to the pH of the emulsion in the method of preparing an emulsion including the microcapsules according to embodiments of the present invention.

8 is a graph showing particle size distribution of the microcapsules included in the emulsion in the emulsion including the microcapsules according to embodiments of the present invention.

Claims (13)

Preparing a fibroin composition by adding proteolytic enzymes to an aqueous solution of fibroin including fibroin and water; And Preparing a mixed solution by adding at least one selected from the group consisting of wax, oil and hydrophobic aliphatic hydrocarbon to the fibroin composition; And Emulsion method comprising a microcapsule comprising the step of stirring the mixed solution. The method of claim 1, wherein the fibroin composition comprises the proteolytic enzyme in a weight ratio of 12 to 40: 1 based on the fibroin. The method of claim 1, wherein the proteolytic enzyme is papain, trypsin, or chymotrypsin. According to claim 1, In the step of preparing the mixed liquid, Emulsion production method comprising a microcapsule, characterized in that it further comprises the step of adding a surfactant. The method of claim 4, wherein the surfactant is added in a volume ratio of 0.3 to 1.2: 1 based on at least one selected from the group consisting of the wax, oil and hydrophobic aliphatic hydrocarbons. . The method of claim 1, wherein after the stirring of the mixed solution, Emulsion production method comprising a microcapsule further comprising the step of adjusting the pH of the mixed solution to 2 to 5. The method of claim 1, wherein the fibroin aqueous solution comprises 0.5 wt% to 5 wt% of the fibroin with respect to the total weight of the fibroin aqueous solution. The method of claim 1, wherein the mixed solution comprises a microcapsule, characterized in that at least one selected from the group consisting of the wax, oil and hydrophobic aliphatic hydrocarbon is added in a volume ratio of 0.05 to 0.2: 1 with respect to the fibroin composition Emulsion Preparation Method. An emulsion comprising a microcapsule having a fibroin shell and a core comprising at least one selected from the group consisting of waxes, oils and hydrophobic aliphatic hydrocarbons. The emulsion of claim 9, wherein the microcapsules have a diameter of 0.3 μm to 10 μm. 10. The emulsion of claim 9, wherein the emulsion has a pH of 2-5. The oil of claim 9, wherein the oil is a polyalcohol ester oil, almond oil, apricot seed oil, avocado oil, theobroma oil, carrot seed oil, castor oil, citrus seed oil, coconut oil, corn oil, cottonseed oil, cucumber oil, egg Oil, jojoba oil, lanolin oil, linseed oil, mineral oil, mink oil, olive oil, palm oil, peach seed oil, peanut oil, rape seed oil, safflower oil, sesame oil, shark liver oil, soybean oil, sunflower seed oil, almond oil, whale oil Emulsion comprising a microcapsule, characterized in that at least one selected from the group consisting of squalene and wheat germ oil. 10. The method of claim 9, wherein the hydrophobic aliphatic hydrocarbon is at least one selected from the group consisting of octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane and octadecane. An emulsion comprising a microcapsule characterized in that.

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