Organic ultraviolet ray cut agent capsules having an effect of increasing ultraviolet ray cut efficiency

Abstract

The present invention relates to an inorganic encapsulation technology for an organic ultraviolet absorber with enhanced temporal stability and ultraviolet cut-off efficiency, and a method for producing the same. In the present invention, an organic UV filter is encapsulated by an encapsulation reaction of an encapsulation component, and at the same time, stabilization conditions of the produced microcapsule emulsion are realized, and high-temperature and temporal stability can be ensured.

Description

Technical Field

[0001] The present invention relates to an organic ultraviolet ray cut agent capsule having excellent ultraviolet ray cut efficiency.

Background Art

[0002] Due to ozone layer depletion caused by environmental pollution, the amount of ultraviolet rays has increased, and the number of people enjoying outdoor sports such as golf, mountain climbing, and fishing has increased, and the demand for ultraviolet ray cut has increased significantly. In particular, the demand for maintaining skin health, from skin cancer to aging, has been increasing day by day. To meet such demands, many studies on ultraviolet ray cut have been conducted.

[0003] Among ultraviolet ray cut agents, in the case of organic UV filters, they play a role of absorbing ultraviolet rays so that ultraviolet rays do not penetrate the skin. However, since UV filters can cause skin irritation and may penetrate the skin, various techniques for encapsulating organic UV filters have been published to prevent this.

[0004] A typical encapsulation method among them is a method of producing a core-shell structure capsule in which an oil phase composed of an organic ultraviolet ray cut agent and a silica precursor is mixed with an aqueous phase in which a surfactant is dispersed, and the organic ultraviolet ray cut agent is surrounded by silica by high-speed emulsification and silica reaction.

[0005] At this time, the capsules exist in the form of an emulsion dispersed in the aqueous phase. However, over time, cards are generated due to aggregation between the capsules, or gelation in the solvent progresses due to the reaction of residual silanol in the aqueous phase, making it difficult to ensure the stability of the capsules over time.

[0006] Therefore, in the prior art, it was essential to perform surface treatment on the capsule surface, or to perform lyophilization to powderize and then perform an additional step of redispersing in a solvent. As an example, in the case of JP 2007-501143 A, after encapsulating an organic UV filter, a method is presented in which it is lyophilized and powdered, and then mixed again with a binder when applied to a dosage form.

[0007] Therefore, in the present invention, an attempt is made to produce microcapsules containing an organic UV filter and to ensure the high-temperature and long-term stability of the microcapsules.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention relates to microcapsules having enhanced long-term stability and ultraviolet cut-off efficiency, and a method for producing the same.

Means for Solving the Problems

[0010] The present invention provides a method for producing microcapsules, comprising the steps of: mixing a continuous phase containing an emulsifier and a dispersed phase containing an organic UV filter and an encapsulating component to produce an emulsion; correcting the specific gravity difference between the continuous phase and the dispersed phase; and adding an organic acid to the emulsion.

[0011] The present invention also provides microcapsules produced by the above-described production method. The present invention is also a method for producing microcapsules, comprising the step of mixing a continuous phase containing an emulsifier and a dispersed phase containing an organic UV filter and an encapsulating component to produce an emulsion, correcting the specific gravity difference between the continuous phase and the dispersed phase; and adding an organic acid to the emulsion; A method for producing microcapsules is provided, characterized by including these steps.

Advantages of the Invention

[0012] In the present invention, microcapsules encapsulating an organic UV filter can be produced, enhancing the ultraviolet cut-off efficiency and ensuring the stability of the capsules over time.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0014] The present invention relates to a method for producing microcapsules, which includes mixing a continuous phase containing an emulsifier and a dispersed phase containing an organic UV filter and an encapsulating component to produce an emulsion (hereinafter, step 1); and correcting the specific gravity difference between the continuous phase and the dispersed phase (hereinafter, step 2); and adding an organic acid to the emulsion (hereinafter, step 3).

[0015] Hereinafter, the configuration of the present invention will be specifically described.

[0016] When a certain part "includes" a certain component, this means that, unless otherwise stated to the contrary, it does not exclude other components and can further include other components.

[0017] In the present invention, Step 1 is a step of mixing a continuous phase and a dispersed phase to produce an emulsion.

[0018] In the present invention, the continuous phase contains an emulsifier. The emulsifier can promote the encapsulation reaction of the encapsulation component described below.

[0019] In one embodiment, the emulsifier can include a tertiary amine-based cationic surfactant. The tertiary amine-based cationic surfactant may be one or more selected from the group consisting of DTAB (Dodecyltrimethyl ammonium bromide), TTAB (Tetradecyltrimethyl ammonium bromide), CTAB (Cetyltrimethyl ammonium bromide), CTMS (Cetyl trimethylammonium methosulfate), STMS (Stearyl trimethylammonium methosulfate), BTMS (Behentrimonium Methosulfate), and Dipalmitoylethyl Dimonium Chloride. In the present invention, Microcare (registered trademark) Quat EQG, which is Dipalmitoylethyl Dimonium Chloride, can be used as the emulsifier. The Dipalmitoylethyl Dimonium Chloride can not only promote the encapsulation reaction of the encapsulation component but also further improve the stability over time of the produced microcapsules.

[0020] In one embodiment, the content of the emulsifier is not particularly limited and may be 0.05 to 5% by weight, 1 to 3% by weight, or 1 to 2% by weight based on the total weight of the components used in the production of the microcapsules. If the content is less than 0.05% by weight, there is a risk of capsule aggregation. If it exceeds 5% by weight, a large amount of foam may be generated during the emulsion production process, and the capsules may emulsify or may not be properly formed. Within the range of the content, the coalescence of the microcapsules can be prevented and the dispersion stability of the emulsion can be ensured.

[0021] In one embodiment, the solvent of the continuous phase is not particularly limited as long as it can dissolve the emulsifier, and water can be used in the present invention.

[0022] In the present invention, the dispersed phase contains an organic UV filter and a component to be encapsulated.

[0023] In the present invention, the organic UV filter means a component containing an organic compound that cuts or absorbs ultraviolet rays, and may generally mean an organic ultraviolet ray-cutting component used in the industry.

[0024] The organic UV filter is used as an active ingredient. The active ingredient is a substance whose activity is desired to be maintained by the generated capsules, and the active ingredient can later exhibit its activity when the outer wall of the capsule is broken. In the present invention, in addition to the organic UV filter, the active ingredient may further contain one or more selected from the group consisting of additional ultraviolet ray-cutting components, fragrances, dyes, catalysts, drugs, and the like. In one embodiment, the organic UV filter may be selected from one or more of ethylhexyl salicylate, avobenzone, p-aminobenzoic acid, bemotrizinol, benzophenone-9, bexophenome-3, bisoctrizole, 3-(4-methylbenzylidene)-camphor, cinoxate, diethylamino hydroxybenzoyl hexyl benzoate, dioxybenzone, drometrizole trisiloxane, ecamsule, ethylhexyl triazone, homosalate, menthyl anthranilate, octocrylene, octyl salicylate, iscotrizinol, isopentenyl-4-methoxycinnamate, octyl-dimethyl-p-aminobenzoic acid, octyl-methoxycinnamate, oxybenzone, polysilicone-15, and trolamine salicylate.

[0025] In one embodiment, the content of the organic UV filter is not particularly limited and can be used in a content of 1 to 80% by weight, 3 to 65% by weight, or 5 to 50% by weight based on the total weight of the components used in the production of the microcapsules.

[0026] In the present invention, the encapsulating component can form the outer wall of the microcapsule (i.e., the shell). Such an encapsulating component may contain one or more selected from the group consisting of a silica precursor, a titanium oxide precursor, and a zirconium oxide precursor.

[0027] In one embodiment, the encapsulating component may contain one or more compounds selected from the group consisting of the compounds represented by the following Chemical Formulas 1 to 4.

Chemical Formula

Chemical Formula

Chemical Formula

Chemical Formula

[0028] In the above Chemical Formulas 1 to 4, A may be silicone, titanium, or zirconium, and R1 to R4 may each independently be hydrogen or an alkyl group having 1 to 8 carbon atoms with a functional group substituted or unsubstituted at the terminal, and the functional group may include amine, hydroxy, amide, carboxy, vinyl, epoxy, phenyl, or mercapto, etc.

[0029] In one embodiment, the silica precursor may include one or more selected from the group consisting of tetraethyl orthosilicate (TEOS), tetramethyl orthosilicate, tetrapropyl orthosilicate, tetrabutyl orthosilicate, dimethyldimethoxysilicate, trimethylmethoxysilicate, methyltrimethoxysilicate, trimethylethoxysilicate, butyltrimethoxysilicate, N-propyltrimethoxysilane, N-octyltrimethoxysilane, aminopropyltrimethoxysilicate, phenyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0030] In one embodiment, the titanium oxide precursor may include one or more selected from the group consisting of titanium methoxide, titanium ethoxide, and titanium butoxide.

[0031] Also, in one embodiment, the zirconium oxide precursor may include one or more selected from the group consisting of zirconium methoxide, zirconium ethoxide, and zirconium butoxide.

[0032] In one embodiment, the content of the encapsulating component is not particularly limited and may be 0.001 to 30% by weight, 0.01 to 25% by weight, or 0.1 to 20% by weight based on the total weight of the components used in the production of the microcapsules. When the content of the encapsulating component is less than 0.001% by weight, there may be a problem that the outer wall of the capsule is formed so thin that it cannot be maintained even if the encapsulation reaction occurs. When it exceeds 30% by weight, there may be a problem that the distinction between the dispersed phase and the continuous phase becomes ambiguous and no capsule is formed.

[0033] In one embodiment, the silica precursor, titanium oxide precursor, and zirconium oxide precursor can be converted into silica, titanium oxide, and zirconium oxide, respectively, by an encapsulation reaction.

[0034] In one embodiment, the solvent of the dispersed phase is not particularly limited as long as it does not mix with the continuous phase when mixed therewith. When water is used as the solvent of the continuous phase, the solvent of the dispersed phase may use one or more selected from the group consisting of hydrocarbon solvents; solvents containing an ether group; solvents containing an ester group; solvents containing a ketone group; solvents containing benzene; haloalkane solvents; and silicone solvents.

[0035] Hydrocarbon solvents may be selected from compounds with linear or non-linear structures such as pentane, hexane, cyclohexane, heptane, octane, isododecane, and dodecane. Solvents containing an ether group may be selected from ethyl ether, butyl ether, and methyl-t-butyl ether. Solvents containing an ester group may be selected from ethyl acetate, butyl acetate, and ethyl butyrate. Also, the solvent containing a ketone group may be methyl ethyl ketone. Solvents containing benzene may be selected from benzene, toluene, and xylene. Haloalkane solvents may be selected from dichloromethane, dichloroethane, chloroform, and carbon tetrachloride. Silicone solvents may be selected from dimethicone and cyclomethicone.

[0036] In the present invention, the aforementioned continuous phase and dispersed phase can be mixed to produce an emulsion.

[0037] In one embodiment, the content of the dispersed phase may be 1 to 60 parts by weight, 2 to 50 parts by weight, or 3 to 40 parts by weight based on the total weight (100 parts by weight) of the mixture of the dispersed phase and the continuous phase.

[0038] In one embodiment, step 1 can be performed by adding the dispersed phase to the continuous phase and can be performed under stirring.

[0039] In one embodiment, the stirring can be performed at 20 to 30 °C or at room temperature at 1 to 16000 rpm, 5 to 13000 rpm, or 10 to 10000 rpm.

[0040] In the present invention, step 2 is a step of correcting the specific gravity difference between the continuous phase and the dispersed phase. By this step, the specific gravity can be corrected in the same manner as the continuous phase, and the problems of floating or precipitation can be solved.

[0041] Microcapsules containing an organic UV filter have a form emulsified and dispersed by an emulsifier in an aqueous phase (i.e., continuous phase) solvent. At this time, a specific gravity difference occurs between the capsule and the aqueous phase solvent, and phenomena such as the capsule sinking or floating on the upper part occur, resulting in problems with stability over time. Also, when the capsules float and sink, the microcapsules start to aggregate with each other, the gelation of the emulsion progresses, and curd is formed.

[0042] In the present invention, in order to prevent such a phenomenon, a sugar compound or oil can be added to the emulsion to correct the specific gravity difference. Alternatively, before the production of the emulsion, the sugar compound or oil can be added to the dispersed phase to adjust the specific gravity difference. By such correction of the specific gravity difference, the stability of the capsules over time can be ensured.

[0043] In one embodiment, the type of the sugar compound is not particularly limited, and one or more selected from the group consisting of monosaccharides such as fructose, glucose, galactose, mannoheptulose, and sedoheptulose; disaccharides such as sucrose, lactose, maltose, trehalose, and cellobiose; and polysaccharides such as cellulose, starch, glycogen, chitin, arabinoxylan, and pectin may be used.

[0044] In one embodiment, the content of the sugar compound is not particularly limited and may vary depending on the specific gravity of the components used in the production of the microcapsules. If the specific gravity of the capsule is greater than that of the continuous phase, the capsule may sink; if it is smaller, a creaming phenomenon may occur where the capsules float in the upper part. At this time, if the specific gravity of the capsule is greater than that of the continuous phase and precipitation occurs, the specific gravity of the continuous phase can be increased through the sugar compound to prevent the precipitation of the capsules. For example, the content of the sugar compound may be 0.001 to 30% by weight, 0.5 to 20% by weight, or 1 to 10% by weight based on the total weight of the components used in the production of the microcapsules.

[0045] In one embodiment, the type of the oil is not particularly limited as long as it is an oil component that can be used in products for the human body. Specifically, the oil may be one or more of the oils commonly used in products for the human body, such as vegetable oil, hydrocarbon oil, ester oil, silicone oil, and synthetic oil. As specific examples of the oil, green tea seed oil, argan kernel oil, olive oil, sunflower seed oil, jojoba seed oil, camellia seed oil, macadamia nut oil, monascus extract, sweet almond oil, castor oil, octyldodecanol, polyglyceryl-2 triisostearate, diisostearyl malate, cetyl ethylhexanoate, tritridecyl trimellitate, squalene, trioctyldodecyl citrate, pentaerythrityl tetraisostearate, caprylic / capric triglyceride, caprylyl methicone, diphenyldimethylsilicone, diphenylsiloxyphenyltrimethylsilicone, isostearic acid, dicaprylyl carbonate, C12-15 alkyl benzoate, dibutyl adipate, isononyl isononanoate, isodecyl phytosteryl / isostearyl / cetyl / stearyl / behenyl dimer dilinoleate, shea butter, ethylhexyl methoxycinnamate, stearalkonium hectorite, acrylates / dimethicone copolymers, polyisobutene, hydrogenated polyisobutene, hydrogenated castor oil dimer dilinoleate, polyglyceryl-2 / isostearic acid / dimer dilinoleic acid copolymer, bis-behenyl / isostearyl / phytosteryl dimer dilinoleic acid dimer dilinoleyl, hydrogenated castor oil isostearic acid, macadamia nut oil polyglyceryl-6 esters behenate, meadowfoam delta-lactone, jojoba ester, dipentaerythrityl hexahydroxystearate / hexastearate / hexarosinate, dilinoleic acid / butanediol copolymer, ethylene / propylene / styrene copolymer, butylene / ethylene / styrene copolymer, petrolatum, dimethicone crosspolymer, and dimethicone / vinyl dimethicone crosspolymer may be used. Preferably, as the oil, two or more oils having different specific gravities may be mixed to adjust the specific gravity difference.For example, the content of the oil may be 0.001 to 30% by weight, 0.5 to 20% by weight, or 1 to 10% by weight based on the total weight of the components used in the production of the microcapsules.

[0046] In one embodiment, step 1 and step 2 can be carried out simultaneously.

[0047] In the present invention, the emulsion can start the encapsulation immediately after production, and the encapsulation can continue to proceed until the reactor of the capsule wall disappears. The encapsulation is, for example, a sol-gel reaction in which a silica precursor solidifies into silica, and the sol-gel reaction can be used in the sense that it includes the hydrolysis and solidification reactions of the silica precursor. Specifically, the encapsulation of the silica precursor can form silanol by a hydrolysis reaction, and the silanol can be solidified by a condensation reaction.

[0048] In the present invention, as a pre-step of step 3 described later, a step of aging the emulsion can be further included. Through the aging process, conditions sufficient for forming the shell, which is the outer wall of the microcapsule, can be provided, and the durability of the microcapsule can be ensured so that it does not easily rupture under external pressure.

[0049] In one embodiment, aging can be carried out at 20 to 30 °C or at room temperature for 1 to 10 days, 1 to 5 days, or 2 to 4 days.

[0050] In the present invention, step 3 is a step of adding an organic acid to the emulsion. In the present invention, the organic acid can be used to improve the stability of the microcapsules.

[0051] In the encapsulation reaction, it is known that when the reaction environment is acidic, the condensation reaction predominates over the hydrolysis reaction, and when it is basic, the hydrolysis reaction predominates.

[0052] As an example, in the present invention, an appropriate amount of organic acid is added to the emulsion to promote the condensation reaction, mainly cause the solidification reaction of silanol on the capsule wall, and improve the stability of the capsule.

[0053] In one embodiment, the type of organic acid is not particularly limited, and one or more selected from the group consisting of citric acid, lactic acid, acetic acid, formic acid, oxalic acid, succinic acid, carbonic acid, benzoic acid, ascorbic acid, carboxylic acid, sulfinic acid, sulfonic acid, fumaric acid, maleic acid, butyric acid, propionic acid, and stearic acid may be used.

[0054] In one embodiment, the content of the organic acid is not particularly limited, and it may be 0.05 to 10% by weight, 0.3 to 8% by weight, or 0.5 to 5% by weight based on the total weight of the components used in the production of the microcapsules. If it is less than 0.05% by weight, gelation of the emulsion occurs, and if it exceeds 10% by weight, the acidity of the emulsion increases, the hydrolysis reaction of the silica precursor mainly occurs, the capsule wall is not firmly formed, and the stability of the microcapsules may decrease.

[0055] In the present invention, microcapsules can be produced by the above-described steps. Specifically, when a silica precursor is used as the encapsulation component, as shown in FIG. 1, stable microcapsules containing the active ingredient can be produced by the hydrolysis and solidification reactions of the silica precursor at the interface between the continuous phase and the dispersed phase. Specifically, since the silica precursor contains alkoxy, it is initially in a state of being mixed with the dispersed phase, which is the core substance. However, when hydrolysis occurs at the emulsion interface, the silica precursor changes to hydrophilicity and becomes laminated at the interface. In that process, a solidification reaction occurs and a solid outer wall is formed.

[0056] In the present invention, the stability of the microcapsules can be improved by using an organic acid. Thereby, even without an additional step of surface treatment and / or freeze-drying on the capsule surface, the produced capsule emulsion itself can ensure high-temperature and stability over time.

[0057] The present invention also relates to microcapsules produced by the method for producing microcapsules described above.

[0058] In one embodiment, the microcapsules may have a diameter of 0.01 to 500 μm, 0.1 to 100 μm, or 0.5 to 5 μm. If the diameter is less than 0.01 μm, the function of protecting the skin by cutting off ultraviolet rays may be reduced. If it exceeds 500 μm, there may be a problem that the stability decreases due to the coalescence of the capsules.

[0059] In one embodiment, the microcapsules according to the present invention can maintain a dispersed state for at least two weeks without precipitation or gelation even at a high temperature of 50°C.

[0060] The present invention also relates to an ultraviolet ray blocking agent containing the aforementioned microcapsules. The dosage form of the ultraviolet ray blocking agent may be a cream, an emulsion, a balm, a factor, etc., and is not limited as long as it is a dosage form that can be used for the dosage form of the ultraviolet ray blocking agent.

[0061] In one embodiment, the content of the microcapsules in the ultraviolet ray blocking agent may be 0.5 to 20 parts by weight, or 1 to 15 parts by weight based on the total weight (100 parts by weight).

[0062] The present invention is also a method for producing microcapsules, which includes mixing a continuous phase containing an emulsifier and a dispersed phase containing an organic UV filter and a capsule component to produce an emulsion, correcting the specific gravity difference between the continuous phase and the dispersed phase; and adding an organic acid to the emulsion; and relates to a method for producing microcapsules, characterized by including the above steps.

[0063] Hereinafter, the present invention will be described in detail with reference to examples. The following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples. These examples are provided to make the disclosure of the present invention complete and to fully inform those skilled in the art to which the present invention pertains of the scope of the present invention. The present invention is defined only by the scope of the claims. The raw materials used in the present invention were purchased from raw material suppliers that can be normally purchased.

Example

[0064] Example 1 and Comparative Examples 1 to 3. Production of Microcapsules Containing Organic UV Filters Microcapsules of the examples and comparative examples were produced with the components and contents (by weight %) shown in Table 1 below.

Table 1

[0065] The methods for producing the microcapsules according to Example 1 and Comparative Example 1 are as follows. (1) A continuous phase in which an emulsifier was dissolved in distilled water at room temperature was produced. At the same time, a silica precursor and an organic UV filter were mixed at room temperature to produce a dispersed phase. (2) The dispersed phase was slowly added to the continuous phase, and the mixture was stirred at a stirring speed of 8,000 rpm for 10 minutes to form an emulsified emulsion. (3) Thereafter, sucrose was slowly added to the emulsion and stirred for 30 minutes. (4) The emulsified emulsion was aged at room temperature for 3 days. (5) Thereafter, citric acid was added.

[0066] The methods for producing the microcapsules according to Example 2 and Comparative Examples 2 and 3 are as follows. (1) A continuous phase in which an emulsifier was dissolved in distilled water at room temperature was produced. At the same time, a silica precursor, an oil, and an organic UV filter were mixed at room temperature to produce a dispersed phase. (2) The dispersed phase was slowly added to the continuous phase, and the mixture was stirred at a stirring speed of 8,000 rpm for 10 minutes to form an emulsion. (3) The emulsion was aged at room temperature for 3 days. (4) Then, citric acid was added.

[0067] Comparative Example 4. Production of Microcapsules Containing an Organic UV Filter Microcapsules were produced by the method of Example 1, except that the process of aging the emulsion at room temperature for 3 days (i.e., (4) in the production method of Example 1) was not performed.

[0068] Experimental Example 1. Comparison of High-Temperature and Long-Term Stability The long-term stability of the microcapsules produced in the above Examples and Comparative Examples was compared.

[0069] While storing the microcapsules at 50 °C and 50% humidity, it was observed whether gelation or precipitation occurred in the emulsion, that is, whether the state in which the microcapsules were dispersed in the aqueous phase was maintained.

[0070] The results are shown in Table 2.

Table 2

[0071] Immediately after production, the microcapsules of Examples 1-2 and Comparative Examples 1-3 all showed a milky white to slightly yellowish non-viscous emulsion state. After 1 day, capsules precipitated in the lower part of the emulsion in Comparative Example 2 to form lumps, and precipitation and gelation were formed on the 4th day in Comparative Example 1. The density of the capsules in Comparative Example 3 was low and they floated on the 1st day. On the other hand, the microcapsules of Examples 1-2 did not show precipitation and gelation at high temperature for up to 2 weeks.

[0072] Summarizing the above results, it was confirmed that the dosage form stability of the emulsion can be ensured with an appropriate content formulation of an emulsifier, a sugar compound, and an organic acid.

[0073] Experimental Example 2. Observation of the morphology of microcapsules It was confirmed whether the microcapsules produced in the above Examples and Comparative Examples were properly formed. Specifically, after the production of the microcapsules, the morphology of the microcapsules was observed using an optical microscope.

[0074] The observation results are shown in Fig. 2. In Fig. 2, (a) shows the morphology of the microcapsules produced in Example 1, and (b) shows the morphology of the microcapsules produced in Comparative Example 4.

[0075] As shown in Fig. 2, for the microcapsules of Example 1, particles with a uniform size of around 1 μm were formed (Fig. 2(a)). On the other hand, in the case of the microcapsules of Comparative Example 4 that did not undergo the aging process, since the time for the silica precursor to solidify into silica to form a shell was not sufficient, it was confirmed that the capsule morphology could not be maintained and they easily burst (Fig. 2(b)).

[0076] Experimental Example 3. Measurement of the average particle size of microcapsules The average particle size of the microcapsules produced in the Examples and Comparative Examples was measured using a Mastersizer 3000 (Malvern).

[0077] After the production of the microcapsules, the average particle size was measured for the first time, and the average particle size was measured for the second time at the 4th week after production to confirm the particle size change, that is, the stability of the capsules over time.

[0078] The above measurement results are shown in Table 3 below.

Table 3

[0079] As shown in Table 3, the appropriate particle size of the capsules according to the present invention is a diameter of 0.5 to 5 μm, and it can be confirmed that the stability over time of the microcapsules produced in Comparative Example 2 decreases.

[0080] Experimental Example 4. Evaluation of ultraviolet cut-off indices (SPF and PA) The UV-cutting ability of the microcapsules produced in Example 1 was confirmed.

[0081] Water-based sunscreen creams of Production Examples 1 to 3 were produced with the components and contents shown in Table 4 below, and their UV-cutting abilities were evaluated.

[0082] In the microcapsules of Example 1 and Comparative Example 4, the content of the organic UV filter was 50% by weight. When 10% by weight of this was added to each of Production Examples 1 to 3, all the UV filters contained in the said production examples were the same at 5% by weight.

[0083] 1. Production of O / W Sunscreen Cream [Table 4]

[0084] The production method is as follows. 1) Component 2 (organic UV filter, Ethylhexyl Salicylate) and 3 were completely dissolved and dispersed at 75°C to produce an oil phase. 2) Components 4 to 8 were uniformly dispersed with a Disper, and then heated to 75°C to produce an aqueous phase. 3) The oil phase was slowly added to the aqueous phase and emulsified with a homomixer at 8,000 rpm for 10 minutes. 4) After cooling to 50°C, Component 1 was added and mixed at 5,000 rpm for 1 minute. 5) After cooling to 30°C, defoaming was carried out.

[0085] 2. Method for Evaluating UV-Cutting Ability The in vitro SPF value was measured by the following method. The sample was applied to a PMMA plate (HelioScreen Labs, France) at a thickness of 1.3 mg / cm 2 and dried for 15 minutes, and then measured through an SPF-290S (Optometrics Corporation, U.S.A.). The average value of the in vitro SPF and PA values measured at six different positions on the PMMA plate was used.

[0086] The measurement results are shown in Table 5 below.

Table 5

[0087] As shown in Table 5 above, in the case of Production Example 2 containing the microcapsules of Example 1, it can be confirmed that compared with the UV cut index of Production Example 1 without microcapsules, the SPF increased by about 89% and the PA increased by about 83%. This means that when the organic UV filter is encapsulated and applied to the dosage form, the UV cut ability is significantly increased compared to the conventional emulsified dosage form.

[0088] In addition, it can be confirmed that Production Example 3 formulated with the capsules according to Comparative Example 3 without aging has no significant difference in the UV cut ability compared to Production Example 1. This means that the capsules are not properly formed and have no efficacy as capsules.

[0089] 3. Evaluation of Skin Permeation of Organic UV Filter The skin permeation of the organic UV filter with or without the use of microcapsules was measured.

[0090] The sunscreen creams according to Production Examples 1 and 2 were applied to the skin of pigs, and the penetration content of the organic UV filter by skin layer was compared.

[0091] First, after putting PBS / EtOH (8 / 2 v / v) as the reservoir solution in the Franz cell, place 2.5 (cm) × 2.5 (cm) of porcine skin with the cutin on top. After placing it on top of the cell, fasten and fix it with a clip. Then, uniformly apply 40 μm of sunscreen on the cutin with a piston pipette. Then, place it in a basket and incubate overnight in a 37°C thermo-hygrostat. The next day, peel off the porcine skin, separate it into each tissue (cutin, epidermis, and dermis), add a certain amount of ethanol, and crush it with a tissue homogenizer. Then, take out the liquid and measure the absorbance with a UV spectrometer to analyze the content of the organic UV filter permeated into each tissue.

[0092] The results are shown in Figure 3.

[0093] As shown in Figure 3, in the case of Production Example 2, the amount of the organic UV filter permeated through all tissue layers was small. In the case of Production Example 1, it was confirmed that a considerable amount of the organic UV filter permeated. Thereby, it can be confirmed that the use of the microcapsules according to the present invention enhances the skin safety.

Industrial Applicability

[0094] In the present invention, microcapsules encapsulating an organic UV filter are manufactured, the ultraviolet cut efficiency can be enhanced, and the stability of the capsules over time can be ensured.

Claims

1. Mixing a continuous phase containing an emulsifier with a dispersed phase containing an organic UV filter and an encapsulated component to produce an emulsion; Correcting the specific gravity difference between the continuous phase and the dispersed phase; and Adding an organic acid to the emulsion; A method for producing microcapsules comprising the steps of:

2. The method for producing microcapsules according to claim 1, wherein the emulsifier comprises a tertiary amine-based cationic surfactant.

3. The emulsifier is selected from the group consisting of DTAB (Dodecyltrimethyl ammonium bromide), TTAB (Tetradecyltrimethyl ammonium bromide), CTAB (Cetyltrimethyl ammonium bromide), CTMS (Cetyl trimethylammonium methosulfate), STMS (Stearyl trimethylammonium methosulfate), BTMS (Behentrimonium Methosulfate), and Dipalmitoylethyl Dimonium Chloride. The method for producing microcapsules according to claim 1, comprising one or more selected from the group consisting of:

4. The content of the emulsifier is 0.05 to 5% by weight based on the total weight of the components used in the production of the microcapsules. The method for producing microcapsules according to claim 1.

5. The method for producing microcapsules according to claim 1, wherein the encapsulated component comprises one or more selected from the group consisting of a silica precursor, a titanium oxide precursor, and a zirconium oxide precursor.

6. The step of correcting the specific gravity difference between the continuous phase and the dispersed phase is the method for producing microcapsules according to claim 1, wherein a sugar compound or oil is added to correct the specific gravity difference.

7. The sugar compound includes one or more selected from the group consisting of monosaccharides such as fructose, glucose, galactose, mannoheptulose and sedoheptulose; disaccharides such as sucrose, lactose, maltose, trehalose and cellobiose; and polysaccharides such as cellulose, starch, glycogen, chitin, arabinoxylan and pectin; The method for producing microcapsules according to claim 6.

8. The content of the sugar compound is 0.001 to 30% by weight based on the total weight of the components used in the production of the microcapsules. The method for producing microcapsules according to claim 6.

9. The method for producing microcapsules according to claim 1 further includes the step of aging the emulsion before adding the organic acid.

10. The aging is carried out at 20 to 30 ° C for 1 to 10 days. The method for producing microcapsules according to claim 9.

11. The organic acid includes one or more selected from the group consisting of citric acid, lactic acid, acetic acid, formic acid, oxalic acid, succinic acid, carbonic acid, benzoic acid, ascorbic acid, carboxylic acid, sulfinic acid, sulfonic acid, fumaric acid, maleic acid, butyric acid, propionic acid and stearic acid; The method for producing microcapsules according to claim 1.

12. The content of the organic acid is 0.05 to 10% by weight based on the total weight of the components used in the production of the microcapsules. The method for producing microcapsules according to claim 1.

13. Produced by the production method according to claim 1, Microcapsules having a diameter of 0.01 to 500 μm.

14. A method for manufacturing microcapsules, comprising the step of mixing a continuous phase containing an emulsifier and a dispersed phase containing an organic UV filter and an encapsulated component to produce an emulsion, correcting the specific gravity difference between the continuous phase and the dispersed phase; and adding an organic acid to the emulsion; The method for manufacturing microcapsules is characterized by comprising the above steps.

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