Calcium alginate colloid capsule as well as preparation method and application thereof

Abstract

The invention relates to the technical field of nano materials and skin care products, in particular to a calcium alginate colloidal capsule and a preparation method and application thereof.The surface of the calcium alginate colloidal capsule is loaded with titanium dioxide nano-particles, and the particle size of the titanium dioxide nano-particles is 120-125 nm; the titanium dioxide nanoparticles are modified by silane. The calcium alginate colloid capsule is prepared by an emulsification-gel method and is used for stabilizing a Pickering emulsion, the colloid capsule is not easy to separate from a liquid drop interface while the sunscreen performance is ensured and the particle volume is increased, the stability of the emulsion is high, and a new thought is provided for research and development of novel cosmetics and application of the Pickering emulsion in the field of daily-use chemical industry.

Description

Technical Field

[0001] The invention relates to the technical field of nano materials and skin care products, and in particular to a calcium alginate colloid capsule and a preparation method and application thereof. Background Art

[0002] The use of sunscreen products can reduce the damage of ultraviolet rays to the skin, reduce the occurrence of skin tanning, inflammation and skin cancer. Generally speaking, sunscreens in sunscreen products can be divided into chemical sunscreens and physical sunscreens. Chemical sunscreens mainly include anthranilate esters, para-aminobenzoic acid derivatives, etc., which absorb ultraviolet rays and convert them into heat and release them on the skin surface through changes in chemical structure. However, these compounds can cause skin allergies, or enter the human body to cause hormone disorders, and also have certain damage to the environment. Physical sunscreens are mainly titanium dioxide nanoparticles (TiO2 NPs), which reduce the contact of ultraviolet rays with the skin through reflection and scattering to achieve sun protection. They have the advantages of high absorbance, high compatibility with sensitive skin and non-irritation. However, TiO2 NPs have a small particle size and are easy to pass through the skin barrier to cause cytotoxicity; and because the sunscreen product emulsion is unstable, the dispersion of TiO2NPs in the emulsion is poor.

[0003] At present, there are two methods to improve the performance of TiO2 NPs while ensuring their sunscreen effect. The first method is to load TiO2 NPs on the surface of solid materials, which not only ensures the functionality of TiO2 NPs but also increases the particle volume. However, this carrier matrix is ​​mainly organic polymer materials, which have problems such as poor dispersibility, incompatibility, and unsustainable sources, and its application in the cosmetics field is limited to a certain extent; the second method is to load TiO2 NPs on the droplet interface to stabilize the Pickering emulsion, which enhances the dispersibility of TiO2 NPs and strengthens the sunscreen performance. However, the desorption free energy of nanoparticles at the emulsion interface is low, and they are easy to fall off from the interface, making the formed emulsion less stable.

[0004] Therefore, it is necessary to develop a sunscreen formula that has both excellent sun protection function and good emulsion stability. Summary of the invention

[0005] The invention aims to solve the problems of poor dispersibility, incompatibility and unsustainable source when titanium dioxide nanoparticles are loaded on the surface of solid materials and the problem that when titanium dioxide nanoparticles are used to stabilize Pickering emulsions at droplet interfaces, the titanium dioxide nanoparticles are easily detached from the interface, resulting in poor stability of the formed emulsion, thereby providing a calcium alginate colloid capsule and a preparation method and application thereof. The calcium alginate colloid capsule with titanium dioxide nanoparticles loaded on the surface is prepared by an emulsification-gel method and is used to stabilize the Pickering emulsion. While ensuring sunscreen performance and increasing particle volume, the colloid capsule is not easy to separate from the droplet interface and the emulsion has high stability, thereby providing new ideas for the research and development of new cosmetics and the application of Pickering emulsions in the field of daily chemical industry.

[0006] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a calcium alginate colloid capsule, wherein the surface of the calcium alginate colloid capsule is loaded with titanium dioxide nanoparticles, wherein: The particle size of the titanium dioxide nanoparticles is 120-125 nm; The titanium dioxide nanoparticles are modified with silane.

[0007] Preferably, the calcium alginate colloid capsule is spherical, and has a particle size of 2-6 μm.

[0008] In a second aspect, the present invention provides a method for preparing a calcium alginate colloid capsule, the preparation method comprising: 1) Add liquid paraffin solution to the calcium alginate solution and mix to obtain emulsion A; 2) Add liquid paraffin solution to the calcium ion solution and mix to obtain emulsion B; 3) cross-linking the emulsion A and the emulsion B, adding anhydrous ethanol, centrifuging, washing, drying and grinding the precipitate; wherein, The liquid paraffin solution contains titanium dioxide nanoparticles and Span 80; The particle size of the titanium dioxide nanoparticles is 120-125 nm; The titanium dioxide nanoparticles are modified with silane.

[0009] Preferably, the mass concentration of titanium dioxide nanoparticles in the liquid paraffin solution is 0.008-0.160 g / mL, and the mass concentration of Span 80 is 0.05-0.07 g / mL.

[0010] Preferably, the titanium dioxide nanoparticles are prepared by hydrolysis of butyl titanate.

[0011] Preferably, the hydrolysis method of butyl titanate comprises: mixing a transparent butyl titanate ethanol solution with water for reaction, washing, drying and grinding the reaction product to obtain titanium dioxide nanoparticles.

[0012] Preferably, the butyl titanate ethanol solution at least meets the following conditions: the volume ratio of butyl titanate to ethanol is 1:1-4.

[0013] Preferably, the volume ratio of the butyl titanate ethanol solution to water is 1:1.

[0014] Preferably, the conditions of the mixing reaction include: adding water dropwise at a uniform speed into the butyl titanate ethanol solution under the conditions of a stirring rate of 800-1200 r / min, a pH of 2-9, and a temperature of 25-37°C.

[0015] Preferably, the silane modification conditions include: dispersing titanium dioxide nanoparticles into a hydrolyzed silane coupling agent solution, and reacting at a temperature of 50-80° C. and a stirring rate of 800-1200 rpm for 6-12 hours.

[0016] Preferably, the silane coupling agent contains 6-8 carbon atoms.

[0017] Preferably, the titanium dioxide nanoparticles need to be placed in a piranha solution for pre-treatment before use.

[0018] Preferably, in step 1), the calcium alginate solution is an aqueous solution with a concentration of 10-20 g / L.

[0019] Preferably, the mixing conditions include: a rotation speed of 800-1200 r / min and a mixing time of 0.5-1.5 h.

[0020] Preferably, in step 2), the calcium ion solution is a calcium chloride aqueous solution with a concentration of 50-90 g / L.

[0021] Preferably, the mixing conditions include: a rotation speed of 800-1200 r / min and a mixing time of 0.5-1.5 h.

[0022] Preferably, in step 3), the conditions of the cross-linking reaction include: the volume ratio of emulsion A to emulsion B is 1:1, the rotation speed is 800-1200 r / min, and the time is 3-7h.

[0023] Preferably, the centrifugal conditions include: a rotation speed of 8000-10000 r / min and a time of 5-10 min.

[0024] Preferably, the washing conditions include: washing with n-hexane 2-4 times.

[0025] Preferably, the drying conditions include: a temperature of 30-40° C. and a time of 12-24 hours.

[0026] In a third aspect, the present invention provides a calcium alginate colloid capsule prepared by the preparation method described in the second aspect.

[0027] In a fourth aspect, the present invention provides a use of the calcium alginate colloid capsule described in the first aspect or the third aspect in the preparation of a sunscreen product.

[0028] In a fifth aspect, the present invention provides a method for preparing a plateau sunscreen repair lotion, the preparation method comprising: dispersing calcium alginate colloid capsules in an organic solvent as an oil phase, dispersing skin care active ingredients in an inorganic solvent as an aqueous phase, and mixing and emulsifying the oil phase and the aqueous phase; Wherein, the calcium alginate colloid capsule is the calcium alginate colloid capsule described in the first aspect or the third aspect; The concentration of calcium alginate colloid capsules in the oil phase is 0.1-2.0 mmol / L; The concentration of the skin care active ingredient is 11-16 mmol / L; The organic solvent is selected from one or two or more of white oil, liquid paraffin and silicone oil; The inorganic solvent is water; The emulsification conditions include: a rotation speed of 10000-12000 r / min and a time of 1-3 min.

[0029] In the above technical solution, the calcium alginate colloid capsule of the present invention is a calcium alginate colloid capsule (Alg@TiO2 colloid capsule) with titanium dioxide nanoparticles (TiO2NPs) loaded on the surface, which improves the dispersibility and biocompatibility of TiO2NPs.

[0030] Furthermore, the Alg@TiO2 colloid capsule of the present invention is prepared by an emulsification-gel method, using safe and stable calcium alginate to react with Ca at room temperature. 2+ Calcium alginate microspheres obtained by gelation were used to load TiO2 NPs, which improved the dispersibility and biocompatibility of TiO2 NPs.

[0031] Furthermore, when Alg@TiO2 colloid capsules are used to stabilize Pickering emulsions using emulsion polymerization, they can ensure sunscreen performance and increase particle volume while also having the advantages of not being easily separated from the droplet interface and having high emulsion stability.

[0032] Furthermore, the plateau sunscreen repairing emulsion of the present invention uses Alg@TiO2 colloid capsules to efficiently encapsulate active ingredients of skin care products, thereby constructing a Pickering emulsion with super emulsion stability and particle dispersibility. The repair mechanism of the plateau sunscreen repair emulsion of the present invention is explored from three levels: particle microstructure, interface microstructure and complex emulsion microstructure. By studying the mechanism of efficient encapsulation caused by interface polymerization, an efficient sunscreen mechanism of Alg@TiO2 colloid capsules stabilizing Pickering emulsion is established; a new mechanism for strengthening the interface stability of Pickering emulsion at multiple levels on the micro-nano scale is explored, which can not only avoid excessive oily sunscreen ingredients in sunscreen skin care products, but also isolate water molecules from entering the interior of the calcium alginate colloid capsules, effectively protecting the easily oxidized skin care active ingredients in the calcium alginate colloid capsules; and because the Alg@TiO2 colloid capsules are located at the emulsion interface, the desorption energy is large, so the prepared Pickering emulsion has super stability and can be applied to special plateau environments with climatic characteristics such as high cold, low pressure, strong ultraviolet rays and large temperature difference between day and night, and it is expected that the Pickering emulsion will be stable for more than 24 months under the climate of the Sichuan-Tibet Plateau. The preparation method of the plateau sunscreen repairing emulsion provided by the invention provides new ideas for the research and development of new cosmetics and the application of Pickering emulsion in the field of daily chemical industry.

[0033] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 The calcium alginate colloid capsule of the present invention encapsulates the skin care active ingredients and stabilizes the Pickering emulsion mechanism; Figure 2 This is the biological repair mechanism of the plateau sunscreen repair emulsion of the present invention; Figure 3 is the particle size (DLS) size distribution of the titanium dioxide nanoparticles prepared in Preparation Example 1 of the present invention; Figure 4 This is a volume fraction diagram of the plateau sunscreen repair emulsion of the present invention at different oil-water ratios after preparation for 1 hour; Figure 5 This is a diagram of the diameter of emulsion droplets of the plateau sunscreen repair emulsion prepared 1 hour after different oil-water ratios of the present invention; Figure 6 is the viscosity change of Picking emulsion under different emulsification conditions; Figure 7The Pickering emulsion prepared in Application Example 5 of the present invention and the aqueous solution of proanthocyanidins (OPC) react with ·OH and ·O 2- clearance rate (CR); Figure 8 It is the sunscreen effect of the Pickering emulsion prepared in Application Example 5 of the present invention; Fig. 9 It is the antioxidant capacity of the Pickering emulsion prepared in Application Example 5 of the present invention after being stabilized for different periods of time in different plateau / non-plateau environments. DETAILED DESCRIPTION

[0035] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0036] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0037] In a first aspect, the present invention provides a calcium alginate colloid capsule, wherein the surface of the calcium alginate colloid capsule is loaded with titanium dioxide nanoparticles, wherein: The particle size of the titanium dioxide nanoparticles is 120-125 nm; The titanium dioxide nanoparticles are modified with silane.

[0038] The calcium alginate colloid capsule of the present invention is a calcium alginate colloid capsule (Alg@TiO2 colloid capsule) with titanium dioxide nanoparticles (TiO2 NPs) loaded on the surface, which improves the dispersibility and biocompatibility of TiO2 NPs.

[0039] In a preferred embodiment of the present invention, in order to make the titanium dioxide nanoparticles have good dispersibility and biocompatibility, the calcium alginate colloid capsule is spherical and has a particle size of 2-6 μm.

[0040] In a second aspect, the present invention provides a method for preparing a calcium alginate colloid capsule, the preparation method comprising: 1) Add liquid paraffin solution to the calcium alginate solution and mix to obtain emulsion A; 2) Add liquid paraffin solution to the calcium ion solution and mix to obtain emulsion B; 3) cross-linking the emulsion A and the emulsion B, adding anhydrous ethanol, centrifuging, washing, drying and grinding the precipitate; wherein, The liquid paraffin solution contains titanium dioxide nanoparticles and Span 80; The particle size of the titanium dioxide nanoparticles is 120-125 nm; The titanium dioxide nanoparticles are modified with silane.

[0041] like Figure 1 (a) shows that it contains Ca 2+ The emulsion B containing calcium alginate is first mixed with the emulsion A containing calcium alginate to make calcium alginate and Ca 2+ Calcium alginate colloid capsules (Alg@TiO2 colloid capsules) are prepared by cross-linking and re-gelation, and effective ingredients such as superoxide dismutase, growth factors, etc. can be added during the preparation of emulsion A.

[0042] The Alg@TiO2 colloid capsule of the present invention is prepared by an emulsification-gel method, using safe and stable calcium alginate to react with Ca at room temperature. 2+ Calcium alginate microspheres obtained by gelation were used to load TiO2 NPs, which improved the dispersibility and biocompatibility of TiO2 NPs.

[0043] In a preferred embodiment of the present invention, in order to make the prepared TiO2 NPs have good dispersibility and biocompatibility, the mass concentration of titanium dioxide nanoparticles in the liquid paraffin solution is 0.008-0.160 g / mL, and the mass concentration of Span 80 is 0.05-0.07 g / mL.

[0044] In a preferred embodiment of the present invention, in order to adjust the particle size, nucleation and growth process of TiO2 NPs, the titanium dioxide nanoparticles are prepared by hydrolysis of butyl titanate.

[0045] In a preferred embodiment of the present invention, in order to adjust the particle size, nucleation and growth process of TiO2 NPs, the butyl titanate hydrolysis method includes: mixing a transparent butyl titanate ethanol solution with water for reaction, washing, drying and grinding the reaction product to obtain titanium dioxide nanoparticles.

[0046] In a preferred embodiment of the present invention, in order to adjust the particle size, nucleation and growth process of TiO2 NPs, the butyl titanate ethanol solution at least meets the following conditions: the volume ratio of butyl titanate to ethanol is 1:1-4.

[0047] In a preferred embodiment of the present invention, in order to adjust the particle size, nucleation and growth process of TiO2 NPs, the volume ratio of the butyl titanate ethanol solution to water is 1:1.

[0048] In a preferred embodiment of the present invention, the butyl titanate ethanol solution may also be replaced by butyl titanate methanol solution.

[0049] In a preferred embodiment of the present invention, in order to adjust the particle size, nucleation and growth process of TiO2 NPs, the conditions of the mixing reaction include: adding water dropwise at a uniform rate to the butyl titanate ethanol solution at a stirring rate of 800-1200 r / min, a pH of 2-9, and a temperature of 25-37°C.

[0050] In a preferred embodiment of the present invention, in order to make the silanol group of the silane coupling agent react with the hydroxyl group (-OH) on the surface of titanium dioxide to form a Si-O-Ti bond, the silane modification conditions include: dispersing titanium dioxide nanoparticles into a hydrolyzed silane coupling agent solution, reacting at a temperature of 50-80°C and a stirring rate of 800-1200rpm for 6-12h, and after the reaction is completed, separating the solid product by centrifugation or filtration.

[0051] In a preferred embodiment of the present invention, the silane coupling agent contains 6-8 carbon atoms.

[0052] like Figure 1 As shown in (b), the titanium dioxide nanoparticles of the present invention can be modified by silanes containing different numbers of carbon atoms. Silane-modified titanium dioxide is usually hydrophobic, and the specific degree of hydrophobicity depends on the type of silane selected, the modification ratio and the process conditions. By adjusting the introduction of hydrophobic groups (such as long-chain alkyl or fluorocarbon chains), controllable regulation from ordinary hydrophobicity to super hydrophobicity can be achieved. The surface of unmodified titanium dioxide is usually hydrophilic due to the presence of hydroxyl groups. For example, anatase and rutile titanium dioxide have strong interactions with water molecules at room temperature and may even form an ordered water layer, but the macroscopic contact angle is still low (about 25°). After silane modification, the surface hydroxyl groups are replaced by hydrophobic groups, thereby reversing its hydrophilic properties, which can better reflect ultraviolet rays, thereby achieving a better sunscreen effect.

[0053] In a preferred embodiment of the present invention, in order to increase the surface hydroxyl content of TiO2 NPs, the titanium dioxide nanoparticles need to be placed in a piranha solution for pretreatment before use.

[0054] In a preferred embodiment of the present invention, the piranha solution is a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 3:1.

[0055] In a preferred embodiment of the present invention, the silane contains 6-10 carbon atoms, for example, KH-540 (γ-aminopropyltrimethoxysilane), KH-792 (N-(2-aminoethyl)-3-aminopropyltrimethoxysilane), KH-570 (γ-(methacryloyloxy)propyltrimethoxysilane), etc.

[0056] In a preferred embodiment of the present invention, in order to prepare calcium alginate microspheres with a suitable particle size, in step 1), the calcium alginate solution is an aqueous solution with a concentration of 10-20 g / L.

[0057] In a preferred embodiment of the present invention, in order to prepare calcium alginate microspheres with a suitable particle size, the mixing conditions include: a rotation speed of 800-1200 r / min and a mixing time of 0.5-1.5 h.

[0058] In a preferred embodiment of the present invention, in order to prepare calcium alginate microspheres with a suitable particle size, in step 2), the calcium ion solution is a calcium chloride aqueous solution with a concentration of 50-90 g / L.

[0059] In a preferred embodiment of the present invention, in order to prepare calcium alginate microspheres with a suitable particle size, the mixing conditions include: a rotation speed of 800-1200 r / min and a mixing time of 0.5-1.5 h.

[0060] In a preferred embodiment of the present invention, in order to make the prepared calcium alginate colloid capsule have good dispersibility and biocompatibility, in step 3), the conditions of the cross-linking reaction include: the volume ratio of emulsion A to emulsion B is 1:1, the rotation speed is 800-1200 r / min, and the time is 3-7h.

[0061] In a preferred embodiment of the present invention, the centrifugal conditions include: a rotation speed of 8000-10000 r / min and a time of 5-10 min.

[0062] In a preferred embodiment of the present invention, in order to obtain pure calcium alginate colloid capsules, the washing conditions include: washing with n-hexane for 2-4 times.

[0063] In a preferred embodiment of the present invention, the drying conditions include: a temperature of 30-40°C and a drying time of 12-24 hours. In a third aspect, the present invention provides a calcium alginate colloid capsule prepared by the preparation method described in the second aspect.

[0064] In a fourth aspect, the present invention provides a use of the calcium alginate colloid capsule described in the first aspect or the third aspect in the preparation of a sunscreen product.

[0065] In a fifth aspect, the present invention provides a method for preparing a plateau sunscreen repair lotion, the preparation method comprising: dispersing calcium alginate colloid capsules in an organic solvent as an oil phase, dispersing skin care active ingredients in an inorganic solvent as an aqueous phase, and mixing and emulsifying the oil phase and the aqueous phase; Wherein, the calcium alginate colloid capsule is the calcium alginate colloid capsule described in the first aspect or the third aspect; The concentration of calcium alginate colloid capsules in the oil phase is 0.1-2.0 mmol / L; The concentration of the skin care active ingredient is 11-16 mmol / L; The organic solvent is selected from one or two or more of white oil, liquid paraffin and silicone oil; The inorganic solvent is water; The emulsification conditions include: a rotation speed of 10000-12000 r / min and a time of 1-3 min.

[0066] like Figure 1 (c) and Figure 2 As shown, the calcium alginate colloid capsule of the present invention is a structure in which surface-modified TiO2 is loaded on the surface of calcium alginate microspheres and dispersed in the form of Pickering emulsion, which fully improves the dispersibility of the particles. The hydroxyl groups on the surface of the TiO2 particles are chemically modified, and the amphiphilicity of the TiO2 particles at the oil-water interface and the mutual attraction between heterogeneous charges can accurately encapsulate skin care active ingredients when the colloid capsule is generated by interfacial polymerization. The skin after sunburn is repaired, and a skin repair model is established, and the skin repair process in which SOD enzyme and epidermal growth factor act together is shown.

[0067] In a preferred embodiment of the present invention, the skin care active ingredient can be green pepper essential oil, epidermal growth factor, collagen, ascorbic acid, SOD, furacillin, urea, camphor, boric acid and other conventional active ingredients in the art.

[0068] The calcium alginate colloid capsule of the present invention utilizes an emulsion polymerization method to make Alg@TiO2 colloid capsules. When used to stabilize Pickering emulsion, the colloid capsules can ensure sunscreen performance and increase particle volume while also having the advantages of being difficult to separate from the droplet interface and having high emulsion stability.

[0069] Furthermore, the plateau sunscreen repairing emulsion of the present invention uses Alg@TiO2 colloid capsules to efficiently encapsulate active ingredients of skin care products, thereby constructing a Pickering emulsion with super emulsion stability and particle dispersibility. The repair mechanism of the plateau sunscreen repair emulsion of the present invention is explored from three levels: particle microstructure, interface microstructure and complex emulsion microstructure. By studying the mechanism of efficient encapsulation caused by interface polymerization, an efficient sunscreen mechanism of Alg@TiO2 colloid capsules stabilizing Pickering emulsion is established; a new mechanism for strengthening the interface stability of Pickering emulsion at multiple levels on the micro-nano scale is explored, which can not only avoid excessive oily sunscreen ingredients in sunscreen skin care products, but also isolate water molecules from entering the interior of the calcium alginate colloid capsules, effectively protecting the easily oxidized skin care active ingredients in the calcium alginate colloid capsules; and because the Alg@TiO2 colloid capsules are located at the emulsion interface, the desorption energy is large, so the prepared Pickering emulsion has super stability and can be applied to special plateau environments with climatic characteristics such as high cold, low pressure, strong ultraviolet rays and large temperature difference between day and night, and it is expected that the Pickering emulsion will be stable for more than 24 months under the climate of the Sichuan-Tibet Plateau. The preparation method of the plateau sunscreen repairing emulsion provided by the invention provides new ideas for the research and development of new cosmetics and the application of Pickering emulsion in the field of daily chemical industry.

[0070] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto. In the following examples, the drugs and medicaments are all conventional commercial products.

[0071] Preparation Example 1 Take 20 mL of butyl titanate and mix it with an appropriate amount of organic solvent 25 mL of anhydrous ethanol, stir evenly, and fully dissolve to obtain a transparent butyl titanate solution; Under stirring conditions, an equal volume of deionized water was added dropwise to the butyl titanate solution, and the dropping speed was controlled to maintain the stability of the reaction system; Reaction conditions: 37°C, ethanol solvent and adjusting the pH of deionized water to 2-3, washing the reaction product to remove residual solvent and impurities and vacuum drying to obtain titanium dioxide nanoparticles; The obtained titanium dioxide nanoparticles were dispersed in water and reacted with the hydrolyzed silane coupling agent KH-540 (γ-aminopropyltrimethoxysilane) at a temperature of 60°C and a stirring rate of 1000 rpm for 8 hours. After the reaction was completed, the solid product, i.e., the modified titanium dioxide nanoparticles, was separated by centrifugation or filtration and was recorded as A1. The particle size (DLS) size distribution was as follows: Figure 3 shown.

[0072] Depend on Figure 3 It can be seen that the average particle size of A1 is 122.9 nm and the dispersion coefficient is 0.18.

[0073] Preparation Example 2 The preparation was carried out according to the preparation method of Preparation Example 1, except that the "pH is 2-3" in Preparation Example 1 was replaced by "pH is 4-5", "pH is 6-7" and "pH is 8-9", respectively, and the other steps remained unchanged, and titanium dioxide nanoparticles were prepared, which were recorded as A2, A3 and A4.

[0074] Preparation Example 3 The preparations were carried out according to the preparation method of Preparation Example 1, except that "37°C" in Preparation Example 1 was replaced by "25°C" and other steps remained unchanged, and titanium dioxide nanoparticles were obtained, which were recorded as A5.

[0075] Preparation Example 4 The preparations were carried out according to the preparation method of Preparation Example 1, except that "ethanol" in Preparation Example 1 was replaced by "methanol" and other steps remained unchanged, and titanium dioxide nanoparticles were obtained, which were recorded as A6.

[0076] Example 1

[0077] 1) Prepare 50 mL of 15 g / L calcium alginate aqueous solution, add 75 mL of liquid paraffin solution containing 0.8 g of TiO2 NPs A1 prepared in Preparation Example 1 and 4.5 g of Span 80, stir magnetically for 1 h at a speed of 1000 r / min, and obtain emulsion A which is synergistically stabilized by TiO2 NPs and Span 80, with liquid paraffin as the external phase and calcium alginate aqueous solution as the internal phase; 2) Prepare 50 mL of 70 g / L calcium chloride aqueous solution, add 75 mL of liquid paraffin solution containing 0.8 g of TiO2NPs A1 prepared in Preparation Example 1 and 4.5 g of Span 80, stir magnetically at a speed of 1000 r / min for 1 h, and prepare emulsion B with liquid paraffin as the outer phase and calcium chloride aqueous solution as the inner phase; 3) Mix emulsion A and emulsion B, stir them magnetically at a speed of 1000 r / min for 5 h to make calcium alginate and Ca 2+ Cross-linking, adding 50 mL of anhydrous ethanol to the cross-linked mixed emulsion to disperse evenly, centrifuging at a speed of 8000 r / min for 5 min to remove the supernatant, washing the precipitate with n-hexane and centrifuging twice, drying at 37°C for 12 h, and grinding to obtain calcium alginate colloidal capsules (Alg@TiO2 colloidal capsules), recorded as B1.

[0078] Example 2

[0079] The preparation was carried out according to the method of Example 1, except that "Preparation Example 1 prepared TiO2 NPs A1" in steps 1)-2) was replaced by "Preparation Example 2 prepared TiO2 NPs A2", "Preparation Example 3 prepared TiO2 NPs A3" and "Preparation Example 4 prepared TiO2 NPs A4", respectively, and the other steps remained unchanged, to obtain Alg@TiO2 colloidal capsules, which were recorded as B2, B3 and B4, respectively.

[0080] Example 3

[0081] The preparation was carried out according to the method of Example 1, except that the "15 g / L calcium alginate aqueous solution" in step 1) was replaced by "10 g / L calcium alginate aqueous solution", and the other steps remained unchanged, to obtain Alg@TiO2 colloidal capsules, which were recorded as B5.

[0082] Example 4

[0083] The preparation was carried out according to the method of Example 1, except that the calcium chloride aqueous solution was changed to 50 g / L, and the other steps remained unchanged to obtain Alg@TiO2 colloidal capsules, which were recorded as B6.

[0084] Example 5

[0085] The preparation was carried out according to the method of Example 1, except that "at a rotation speed of 1000 r / min" in steps 1)-3) was replaced by "at a rotation speed of 800 r / min", and the other steps remained unchanged, to obtain Alg@TiO2 colloidal capsules, which were recorded as B7.

[0086] Application Example 1 At room temperature (20-30°C), 2 mg of the Alg@TiO2 colloidal capsule B1 of Example 1 was ultrasonically dispersed in 1 mL of white oil as the oil phase, and RO water was used as the water phase. The mixed solution with an oil-water ratio (volume ratio) of 0.8:1 was placed in a portable high-speed disperser and emulsified at a speed of 10000 r / min for 1 min to obtain a Pickering emulsion stabilized by the Alg@TiO2 colloidal capsule.

[0087] Application Example 2 The preparation was carried out according to the method of Application Example 1, except that the "oil-water ratio (volume ratio) is 0.8:1" in Application Example 1 was replaced by "oil-water ratio (volume ratio) is 1:1", and the other steps remained unchanged to prepare the Alg@TiO2 colloidal capsule stabilized Pickering emulsion.

[0088] Application Example 3 The preparation was carried out according to the method of Application Example 1, except that the "oil-water ratio (volume ratio) is 0.8:1" in Application Example 1 was replaced by "oil-water ratio (volume ratio) is 1.5:1", and the other steps remained unchanged to prepare the Alg@TiO2 colloidal capsule stabilized Pickering emulsion.

[0089] Application Example 4 The preparation was carried out according to the method of Application Example 1, except that the "oil-water ratio (volume ratio) is 0.8:1" in Application Example 1 was replaced by "oil-water ratio (volume ratio) is 2:1", and the other steps remained unchanged to prepare the Alg@TiO2 colloidal capsule stabilized Pickering emulsion.

[0090] Test Example 1 The emulsion volume fraction (φ) and emulsion droplet diameter of the Pickering emulsions prepared in Application Examples 1-4 were measured respectively. The results are as follows: Figure 4-5 shown.

[0091] Figure 4 The emulsion volume fractions of Pickering emulsions prepared with different oil-water ratios are shown. It can be seen that the emulsion volume fraction is the largest when the oil-water ratio is 1:1. Figure 5 It can be seen that at the same microsphere content, the oil-water ratio has a certain effect on the diameter of the emulsion droplets. When the oil-water ratio is gradually adjusted from 0.8:1 to 2:1, the diameter changes from 170 μm to 240 μm. In summary, the emulsion prepared when the oil-water ratio is 1:1 has a better emulsification effect.

[0092] Test Example 2 To investigate the effect of ultrasonic emulsification conditions on the emulsion formation of Alg@TiO2 colloidal capsule-stabilized Pickering emulsion: Measure the viscosity of the system and systematically explore the factors that affect the efficiency and stability of the emulsion system.

[0093] The emulsification conditions are shown in Table 1.

[0094] Table 1 Emulsification conditions

[0095] From the data in Table 1 and Figure 6 The results show that too large or too small ultrasonic power will affect the emulsification effect of the Picking emulsion. In the present invention, an emulsification power of 40w can achieve the best viscosity effect; as the emulsification time increases, the emulsification effect increases, but emulsification for more than 10 minutes will cause the Picking emulsion to be unstable and reduce the viscosity.

[0096] Application Example 5 2 mg of the Alg@TiO2 colloid capsule B1 of Example 1 was ultrasonically dispersed in 1 mL of white oil as the oil phase, and 5 mL each of 0.1 mmol / L of an aqueous solution of green pepper essential oil, 0.1 mmol / L of an aqueous solution of epidermal growth factor, 0.1 mmol / L of an aqueous solution of collagen, 0.1 mmol / L of an aqueous solution of ascorbic acid, and 0.1 mmol / L of an aqueous solution of SOD were mixed as the water phase, and placed in a portable high-speed disperser with an oil-water ratio (volume ratio) of 1:1, and emulsified at a speed of 10000 r / min for 1 min to obtain a Pickering emulsion stabilized by the drug-loaded Alg@TiO2 colloid capsules.

[0097] Application Example 6 The preparation was carried out according to the method of Application Example 5, except that the "5 mL each of 0.1 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.1 mmol / L aqueous solution of epidermal growth factor, 0.1 mmol / L aqueous solution of collagen, 0.1 mmol / L aqueous solution of ascorbic acid and 0.1 mmol / L aqueous solution of SOD were mixed as the aqueous phase" in Application Example 5 was replaced by "5 mL each of 0.2 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.2 mmol / L aqueous solution of epidermal growth factor, 0.2 mmol / L aqueous solution of collagen, 0.2 mmol / L aqueous solution of ascorbic acid and 0.2 mmol / L aqueous solution of SOD were mixed as the aqueous phase", and the other steps remained unchanged to obtain a Pickering emulsion stabilized by drug-loaded Alg@TiO2 colloid capsules.

[0098] Application Example 7 The preparation was carried out according to the method of Application Example 5, except that the "5 mL each of 0.1 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.1 mmol / L aqueous solution of epidermal growth factor, 0.1 mmol / L aqueous solution of collagen, 0.1 mmol / L aqueous solution of ascorbic acid and 0.1 mmol / L aqueous solution of SOD were mixed as the aqueous phase" in Application Example 5 was replaced by "5 mL each of 0.4 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.4 mmol / L aqueous solution of epidermal growth factor, 0.4 mmol / L aqueous solution of collagen, 0.4 mmol / L aqueous solution of ascorbic acid and 0.4 mmol / L aqueous solution of SOD were mixed as the aqueous phase", and the other steps remained unchanged to obtain a Pickering emulsion stabilized by drug-loaded Alg@TiO2 colloid capsules.

[0099] Application Example 8 The preparation was carried out according to the method of Application Example 5, except that the "5 mL each of 0.1 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.1 mmol / L aqueous solution of epidermal growth factor, 0.1 mmol / L aqueous solution of collagen, 0.1 mmol / L aqueous solution of ascorbic acid and 0.1 mmol / L aqueous solution of SOD were mixed as the aqueous phase" in Application Example 5 was replaced by "5 mL each of 0.5 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.5 mmol / L aqueous solution of epidermal growth factor, 0.5 mmol / L aqueous solution of collagen, 0.5 mmol / L aqueous solution of ascorbic acid and 0.5 mmol / L aqueous solution of SOD were mixed as the aqueous phase", and the other steps remained unchanged to obtain a Pickering emulsion stabilized by drug-loaded Alg@TiO2 colloid capsules.

[0100] Application Example 9 The preparation was carried out according to the method of Application Example 5, except that the "5 mL each of 0.1 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.1 mmol / L aqueous solution of epidermal growth factor, 0.1 mmol / L aqueous solution of collagen, 0.1 mmol / L aqueous solution of ascorbic acid and 0.1 mmol / L aqueous solution of SOD were mixed as the aqueous phase" in Application Example 5 was replaced by "5 mL each of 0.7 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.7 mmol / L aqueous solution of epidermal growth factor, 0.7 mmol / L aqueous solution of collagen, 0.7 mmol / L aqueous solution of ascorbic acid and 0.7 mmol / L aqueous solution of SOD were mixed as the aqueous phase", and the other steps remained unchanged to obtain a Pickering emulsion stabilized by drug-loaded Alg@TiO2 colloid capsules.

[0101] Application Example 10 The preparation was carried out according to the method of Application Example 5, except that the "5 mL each of 0.1 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.1 mmol / L aqueous solution of epidermal growth factor, 0.1 mmol / L aqueous solution of collagen, 0.1 mmol / L aqueous solution of ascorbic acid and 0.1 mmol / L aqueous solution of SOD were mixed as the aqueous phase" in Application Example 5 was replaced by "5 mL each of 1.0 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 1.0 mmol / L aqueous solution of epidermal growth factor, 1.0 mmol / L aqueous solution of collagen, 1.0 mmol / L aqueous solution of ascorbic acid and 1.0 mmol / L aqueous solution of SOD were mixed as the aqueous phase", and the other steps remained unchanged to obtain a Pickering emulsion stabilized by drug-loaded Alg@TiO2 colloid capsules.

[0102] Application Example 11 The preparation was carried out according to the method of Application Example 5, except that the "5 mL each of 0.1 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 0.1 mmol / L aqueous solution of epidermal growth factor, 0.1 mmol / L aqueous solution of collagen, 0.1 mmol / L aqueous solution of ascorbic acid and 0.1 mmol / L aqueous solution of SOD were mixed as the aqueous phase" in Application Example 5 was replaced by "5 mL each of 2.0 mmol / L aqueous solution of Zanthoxylum bungeanum essential oil, 2.0 mmol / L aqueous solution of epidermal growth factor, 2.0 mmol / L aqueous solution of collagen, 2.0 mmol / L aqueous solution of ascorbic acid and 2.0 mmol / L aqueous solution of SOD were mixed as the aqueous phase", and the other steps remained unchanged to obtain a Pickering emulsion stabilized by drug-loaded Alg@TiO2 colloid capsules.

[0103] Test Example 3 Release of active ingredients in skin care from Alg@TiO2 colloid capsules: The drug-loaded Alg@TiO2 colloid capsules of Application Example 5 were disintegrated and dispersed into the oily solution of skin care products. The absorption spectrum was scanned at the full wavelength (200-800 nm) using an ultraviolet spectrophotometer to observe the degree of absorption change of the active ingredients in the skin care products within the full wavelength range.

[0104] The disintegration conditions are shown in Table 2.

[0105] Table 2 Disintegration conditions

[0106] From the contents of Table 2, we can deduce the rules that affect the drug release of drug-loaded Alg@TiO2 colloid capsules, that is, at room temperature, the Pickering emulsion can maintain the emulsion state, and heating (close to human body temperature) is conducive to the disintegration of the Pickering emulsion and the release of drugs, while the disintegration pressure has little effect on the disintegration characteristics of the Pickering emulsion.

[0107] Test Example 4 Alg@TiO2 colloid capsule surface micro-nanostructure enhances bioremediation: 1) Test of •OH scavenging ability: Under the condition that the total volume of the reaction system is 200 µL, 50 µL of 10 μM dichlorofluorescein diacetate (DCFH-DA) was added to 50 µL of the Pickering emulsion stabilized by the drug-loaded Alg@TiO2 colloidal capsules in Application Example 5 (the final concentration of the drug-loaded Alg@TiO2 colloidal capsules was 10 µM), and then 50 µL of hydrogen peroxide (H2O2) solution was added (the final concentration of H2O2 was 100 µM) to generate •OH free radicals. After the reaction system was incubated at 37°C for 30 minutes, the fluorescence intensity was measured at 520 nm by excitation at 485 nm using a UV spectrophotometer to calculate the clearance rate.

[0108] In the control experiment, an aqueous solution of proanthocyanidins (OPC) of the same concentration was used to replace the Pickering emulsion stabilized by the drug-loaded Alg@TiO2 colloidal capsules in Application Example 5, and other conditions remained unchanged.

[0109] 2) Test of O2•⁻ removal capacity: Under the condition that the total volume of the reaction system is 200 μL, 50 μL of the Pickering emulsion stabilized by the drug-loaded Alg@TiO2 colloidal capsules in Application Example 5 is reacted with 50 μL of nitrothionyl chloride (NBT) and 50 μL of NADH. Among them, the final concentration of drug-loaded Alg@TiO2 colloidal capsules was 10 µM, the final concentration of NBT was 0.5 mM, and the final concentration of NADH was 0.05 mM. After 30 min of reaction, the absorbance was measured at 560 nm by a spectrophotometer to calculate the clearance rate.

[0110] In the control experiment, an aqueous solution of proanthocyanidins (OPC) of the same concentration was used to replace the Pickering emulsion stabilized by the drug-loaded Alg@TiO2 colloidal capsules in Application Example 5, and other conditions remained unchanged.

[0111] The results are as follows Figure 7 As shown, the Pickering emulsion prepared by the present invention has a better ability to scavenge free radicals than the proanthocyanidin solution and can scavenge more than 80% of free radicals in the environment, including hydroxyl radicals and superoxide anions.

[0112] Test Example 5 Application solutions for high-efficiency sun protection and bioremediation performance: Fresh pig skin was used for testing in the early stage. After obtaining stable data, volunteers' hand skin was selected for testing. The sun protection ability evaluation scheme was carried out according to ISO24444. Specifically, 2 mg / cm 3The drug-loaded Alg@TiO2 colloid capsules prepared in Application Example 5 of the present invention and market samples 1-2 were then exposed to a UVB light source, and the skin erythema reaction time was recorded and the SPF value was calculated with the sample group that did not use sunscreen. The results are as follows Figure 8 shown.

[0113] Depend on Figure 8 It can be seen that the Pickering emulsion of the present invention has an SPF of over 60, which is significantly higher than the equivalent products on the market and has a good sun protection effect.

[0114] Test Example 6 Stability application solutions for special plateau environments: 2 mg of the Alg@TiO2 colloidal capsule B1 of Example 1 was ultrasonically dispersed in 1 mL of white oil as the oil phase, and 5 mL each of 0.1 mmol / L furacillin aqueous solution, 0.1 mmol / L urea aqueous solution, 0.1 mmol / L camphor aqueous solution and 0.1 mmol / L boric acid aqueous solution were mixed as the water phase, placed in a portable high-speed disperser with an oil-water ratio (volume ratio) of 1:1, and emulsified at a speed of 10000 r / min for 1 min to obtain a Pickering emulsion stabilized by Alg@TiO2 colloidal capsules containing anti-freeze and anti-cracking medicinal ingredients.

[0115] When the Pickering emulsion stabilized by Alg@TiO2 colloid capsules containing anti-freeze and anti-cracking medicinal ingredients is applied to the special plateau environment with high cold, low pressure, strong ultraviolet rays and large temperature difference between day and night, the prepared emulsion has the characteristics of super stability because the Alg@TiO2 colloid capsules are located at the emulsion interface, resulting in large desorption energy. The stability of the Pickering emulsion was evaluated by storing it in plateau (Lhasa) and non-plateau (Chengdu) environments and continuously observing and recording the state of the Pickering emulsion. The recording items included whether there was stratification, flocculation, precipitation or rancidity (100 samples in each group, 50 indoors and 50 outdoors). The antioxidant capacity of the Pickering emulsion before and after storage was evaluated with reference to Test Examples 4 and 5. The results are as follows: Fig. 9 And as shown in Table 3.

[0116] Table 3 Pickering emulsion stability

[0117] Depend on Fig. 9 As can be seen from the data in Table 3, the Pickering emulsion prepared in the present invention still has good antioxidant capacity and good stability after being placed in the climate of the Sichuan-Tibet Plateau for 24 months.

[0118] In summary, the Pickering emulsion stabilized by the drug-loaded Alg@TiO2 colloid capsule of the present invention can not only avoid excessive oily sunscreen ingredients in sunscreen skin care products, but also isolate water molecules from entering the interior of the colloid capsule, effectively protecting the easily oxidized skin care active ingredients in the colloid capsule. TiO2 nanoparticles are dispersed at the interface of the Pickering emulsion in the form of colloid capsules, and are evenly dispersed to the skin after application, providing a super strong ability to protect against ultraviolet rays. After a period of outdoor activities, due to the action of the internal skin care active ingredients, free radicals are eliminated in a coordinated manner, and the damaged skin is repaired.

[0119] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0120] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0121] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A calcium alginate colloid capsule, characterized in that: The surface of the calcium alginate colloid capsule is loaded with titanium dioxide nanoparticles; wherein, The particle size of the titanium dioxide nanoparticles is 120-125 nm; The titanium dioxide nanoparticles are modified with silane.

2. The calcium alginate colloid capsule according to claim 1, characterized in that: The calcium alginate colloid capsule is spherical and has a particle size of 2-6 μm.

3. A method for preparing calcium alginate colloid capsules, characterized in that: The preparation method comprises: 1) Add liquid paraffin solution to the calcium alginate solution and mix to obtain emulsion A; 2) Add liquid paraffin solution to the calcium ion solution and mix to obtain emulsion B; 3) cross-linking the emulsion A and the emulsion B, adding anhydrous ethanol, centrifuging, washing, drying and grinding the precipitate; wherein, The liquid paraffin solution contains titanium dioxide nanoparticles and Span 80; The particle size of the titanium dioxide nanoparticles is 120-125 nm; The titanium dioxide nanoparticles are modified with silane.

4. The preparation method according to claim 3, characterized in that: The mass concentration of titanium dioxide nanoparticles in the liquid paraffin solution is 0.008-0.160 g / mL, and the mass concentration of Span 80 is 0.05-0.07 g / mL; and / or, The titanium dioxide nanoparticles are prepared by hydrolysis of butyl titanate; and / or, The method for hydrolyzing butyl titanate comprises: mixing a transparent butyl titanate ethanol solution with water for reaction, washing, drying and grinding the reaction product to obtain titanium dioxide nanoparticles; and / or, The volume ratio of the butyl titanate ethanol solution to water is 1:1; and / or, The conditions of the mixing reaction include: adding water dropwise at a uniform speed into the butyl titanate ethanol solution under the conditions of a stirring rate of 800-1200 r / min, a pH of 2-9, and a temperature of 25-37° C.; and / or, The butyl titanate ethanol solution at least meets the following conditions: the volume ratio of butyl titanate to ethanol is 1:1-4; and / or, The silane modification conditions include: dispersing titanium dioxide nanoparticles into a hydrolyzed silane coupling agent solution, reacting at a temperature of 50-80° C. and a stirring rate of 800-1200 rpm for 6-12 hours; and / or, The silane coupling agent contains 6-8 carbon atoms; and / or, The titanium dioxide nanoparticles need to be placed in a piranha solution for pretreatment before use.

5. The preparation method according to claim 3 or 4, characterized in that: In step 1), the calcium alginate solution is an aqueous solution with a concentration of 10-20 g / L; and / or, The mixing conditions include: a rotation speed of 800-1200 r / min and a mixing time of 0.5-1.5 h.

6. The preparation method according to claim 3 or 4, characterized in that: In step 2), the calcium ion solution is a calcium chloride aqueous solution with a concentration of 50-90 g / L; and / or, The mixing conditions include: a rotation speed of 800-1200 r / min and a mixing time of 0.5-1.5 h.

7. The preparation method according to claim 3 or 4, characterized in that: In step 3), the conditions of the cross-linking reaction include: the volume ratio of emulsion A to emulsion B is 1:1, the rotation speed is 800-1200 r / min, and the time is 3-7h; and / or, The centrifugal conditions include: a rotation speed of 8000-10000 r / min and a time of 5-10 min; and / or, The washing conditions include: washing with n-hexane 2-4 times; and / or, The drying conditions include: a temperature of 30-40° C. and a drying time of 12-24 hours.

8. A calcium alginate colloid capsule prepared by the preparation method according to any one of claims 3 to 7.

9. Use of the calcium alginate colloid capsule according to claim 1 or 2 or the calcium alginate colloid capsule according to claim 8 in the preparation of sunscreen products.

10. A method for preparing a plateau sunscreen repair lotion, characterized in that: The preparation method comprises: dispersing calcium alginate colloid capsules in an organic solvent as an oil phase, dispersing skin care active ingredients in an inorganic solvent as a water phase, and mixing and emulsifying the oil phase and the water phase; Wherein, the calcium alginate colloid capsule is the calcium alginate colloid capsule according to claim 1 or 2 or the calcium alginate colloid capsule according to claim 8; The concentration of calcium alginate colloid capsules in the oil phase is 0.1-2.0 mmol / L; The concentration of the skin care active ingredient is 11-16 mmol / L; The organic solvent is selected from one or two or more of white oil, liquid paraffin and silicone oil; The inorganic solvent is water; The emulsification conditions include: a rotation speed of 10000-12000 r / min and a time of 1-3 min.

Images