High SPF soothing and repairing sunscreen microspheres suitable for sensitive skin and preparation method

Abstract

The invention discloses a kind of high SPF soothing and repairing sunscreen microsphere and preparation method suitable for sensitive skin, which belongs to the field of cosmetic technology; the high SPF soothing and repairing sunscreen microsphere suitable for sensitive skin provided by the invention is a core-shell structure; the core layer includes titanium dioxide and zinc oxide; the shell layer includes plant extract and sodium alginate, and the plant extract includes guaiac extract, camellia extract, perilla leaf extract and immortelle extract; the sum of the mass of the titanium dioxide and zinc oxide and the sum of the mass of the plant extract and sodium alginate is 1: (1.3-4.8). The sunscreen microsphere provided by the invention has excellent anti-ultraviolet effect, and is gentle and non-irritating; at the same time, the sunscreen microsphere obtained also has excellent anti-inflammatory, anti-oxidation and soothing after sun exposure, and repairs the skin barrier. In addition, the sunscreen microsphere preparation method provided by the invention is simple to operate, which is conducive to actual production.

Description

Technical Field

[0001] The invention belongs to the technical field of cosmetics, and in particular relates to high SPF soothing repairing sunscreen microspheres suitable for sensitive skin and a preparation method thereof. Background Art

[0002] Sunscreen products are made by adding sunscreens that reflect or absorb ultraviolet radiation to reduce the damage to the skin caused by ultraviolet rays. Most current sunscreen products use a combination of physical sunscreen and chemical sunscreen. Physical sunscreen, also known as barrier sunscreen, protects the skin by reflecting ultraviolet rays. Physical sunscreens generally include zinc oxide, titanium dioxide, etc., which generally require a large amount of polar oils to dissolve, making the skin feel greasy, and the skin is not breathable after application, causing clogged pores; chemical sunscreen protects the skin by absorbing ultraviolet rays. In addition, physical sunscreens are easy to penetrate into the stratum corneum of the skin after application, causing irritation to the skin and causing skin inflammation. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a sunscreen microsphere containing guaiac extract, which has excellent ultraviolet absorption effect, certain antioxidant, anti-inflammatory and soothing effects, can relieve skin irritation after sun exposure, and repair skin barrier effects, as well as a preparation method and application thereof.

[0004] To achieve the above object, in a first aspect of the present invention, the present invention provides a high SPF soothing and repairing sunscreen microsphere suitable for sensitive skin, wherein the sunscreen microsphere is a core-shell structure, wherein the core layer comprises titanium dioxide and zinc oxide, and the shell layer comprises plant extracts and sodium alginate, wherein the plant extracts comprise guaiac extract, camellia extract, perilla leaf extract, and immortelle extract;

[0005] The ratio of the sum of the mass of the titanium dioxide and the zinc oxide to the sum of the mass of the plant extract and the sodium alginate is 1:(1.3-4.8).

[0006] The present invention uses appropriate mass parts of titanium dioxide and zinc oxide as a core layer structure, which is wrapped in a shell layer structure formed by appropriate mass parts of plant extracts and sodium alginate, which can solve the problem of titanium dioxide and zinc oxide penetrating into the skin due to their small size, thereby reducing skin inflammation caused by the penetration stimulation of titanium dioxide and zinc oxide. At the same time, the shell layer structure of the present invention includes plant extracts and sodium alginate. On the first hand, sodium alginate has an excellent wrapping and supporting effect; on the second hand, the guaiac extract in the plant extract can cooperate with sodium alginate as a film material to improve the encapsulation rate of the sunscreen microspheres; on the third hand, the plant extracts have a good synergistic effect, which can improve the ability of the sunscreen microspheres to absorb ultraviolet rays, and also have excellent anti-inflammatory, antioxidant and sun-soothing effects on the skin.

[0007] Specifically, the guaiac wood extract is rich in lignin and cellulose, wherein lignin is a natural UV absorbing material with an aromatic structure and chemical bonds such as phenol and ketone, showing excellent UV absorption capacity; and, after lignin is phenolized by tea polyphenols, its UV absorption capacity is greatly improved; camellia extract contains more phenolic substances, so, using it together with guaiac wood extract can effectively enhance the guaiac wood extract's ability to absorb UV rays; at the same time, the polyphenols contained in camellia extract can also work together with the flavonoids in the perilla leaf extract to achieve an excellent free radical scavenging effect; the active ingredients in immortelle can also further work together with saponins, terpenes and other ingredients in the guaiac wood extract to play a good anti-inflammatory and after-sun soothing and repairing role.

[0008] Exemplarily, the ratio of the sum of the masses of the titanium dioxide and zinc oxide to the sum of the masses of the plant extract and sodium alginate can be 1:(1.3-4.8) at any point or in the range of any two points, such as 1:1.3, 1:1.5, 1:1.8, 1:2.0, 1:2.2, 1:2.5, 1:2.8, 1:3.0, 1:3.2, 1:3.5, 1:3.8, 1:4.0, 1:4.2, 1:4.5, 1:4.8, etc.

[0009] As a preferred embodiment of the sunscreen microspheres described in the present invention, the mass ratio of guaiac extract, camellia extract, perilla leaf extract and immortelle extract is guaiac extract: camellia extract: perilla leaf extract: immortelle extract = (1-2): (3-5): (1-3): 1.

[0010] The present invention has found that the mass ratio of guaiac extract, camellia extract, perilla leaf extract and immortelle extract not only affects the product's ability to absorb ultraviolet rays and soothe after-sun exposure, but also affects the product's encapsulation rate; when the mass ratio of guaiac extract, camellia extract, perilla leaf extract and immortelle extract is further selected within the above range, the comprehensive effect of the obtained product is better.

[0011] As a preferred embodiment of the sunscreen microspheres of the present invention, the mass percentage of sodium alginate is 0.3-1% based on the total mass of the plant extract, titanium dioxide and zinc oxide.

[0012] The amount of sodium alginate added will affect the encapsulation rate of the product, and will also have a certain impact on the ultraviolet absorption ability of the product; when the mass percentage of sodium alginate is further selected to be 0.3-1%, not only the encapsulation rate of the obtained sunscreen microspheres is higher, but also the ultraviolet absorption ability of the obtained product is stronger; at the same time, the particle size of the obtained product is moderate and can be effectively used in the preparation of subsequent sunscreen finished products.

[0013] As a preferred embodiment of the sunscreen microspheres of the present invention, the mass ratio of titanium dioxide to zinc oxide is (0.5-3):1.

[0014] The present invention has found that the mass ratio of titanium dioxide to zinc oxide will affect the encapsulation rate and ultraviolet absorption capacity of the product. When the mass ratio of titanium dioxide to zinc oxide is further selected to be within the above range, the obtained product has a higher encapsulation rate and a stronger ultraviolet absorption capacity.

[0015] As a preferred embodiment of the sunscreen microspheres described in the present invention, the preparation method of the guaiac extract comprises the following steps: adding guaiac powder to a 1,3-butanediol aqueous solution and heating to 160-180°C for extraction for 1-4 hours, followed by cooling and filtering, collecting and concentrating the filtrate to obtain the guaiac extract.

[0016] Preferably, the mass volume ratio of guaiac wood powder to 1,3-butanediol aqueous solution is 1 g: (8-10) mL.

[0017] Preferably, in the 1,3-butanediol aqueous solution, the mass percentage of 1,3-butanediol is 30-50%.

[0018] The present invention has found that the guaiac extract prepared by the preparation method of the present invention can not only better cooperate with sodium alginate to form a stable shell structure, improve the encapsulation rate of the product, and make the product have a suitable particle size range, but also can better cooperate with the camellia extract, the perilla leaf extract and the immortelle flower extract, and on the basis of improving the product's ability to absorb ultraviolet rays, further improve the product's antioxidant, anti-inflammatory and after-sun soothing and repairing abilities.

[0019] As a preferred embodiment of the sunscreen microspheres of the present invention, the preparation method of the camellia extract comprises the following steps: crushing the camellia, adding it to water and heating it to 60-80°C for extraction, filtering after the extraction, collecting and concentrating the filtrate to obtain the camellia extract.

[0020] Preferably, the solid-liquid ratio of the extraction is 1 g: (8-12) mL.

[0021] Preferably, the extraction time is 0.5-1.5h.

[0022] Preferably, the concentration is carried out until the relative density of the concentrated liquid is 1.02-1.07.

[0023] As a preferred embodiment of the sunscreen microspheres of the present invention, the preparation method of the perilla leaf extract comprises the following steps: taking the perilla leaf, crushing it, adding it into water and heating it to 50-70°C for extraction, filtering it after the extraction is completed, collecting the filtrate and concentrating it to obtain the perilla leaf extract.

[0024] Preferably, the solid-liquid ratio of the extraction is 1 g: (6-10) mL.

[0025] Preferably, the extraction time is 20-40 min.

[0026] As a preferred embodiment of the sunscreen microspheres of the present invention, the preparation method of the immortelle flower extract comprises the following steps: crushing the immortelle flower and adding it into water, stirring and extracting at room temperature, and filtering after the extraction to obtain the immortelle flower extract.

[0027] Preferably, the solid-liquid ratio of the extraction is 1 g: (8-12) mL.

[0028] Preferably, the extraction time is 1-3 hours.

[0029] In the second aspect of the present invention, the present invention provides a method for preparing the sunscreen microspheres, the preparation method comprising the following steps:

[0030] (1) mixing the guaiac extract and the camellia extract and adjusting the pH value to 2-3, then stirring at 70-90° C. for 0.5-3 h, cooling after the stirring and adjusting the pH value to 5.5-6.5, then adding the perilla leaf extract and the immortelle flower extract, and mixing evenly to obtain a plant composition;

[0031] (2) dispersing titanium dioxide and zinc oxide in water, adding the plant composition prepared in step (1) and sodium alginate, and mixing evenly to obtain a titration solution;

[0032] (3) Drop the titration solution into a receiving solution containing calcium chloride to obtain sunscreen microspheres under the action of an electric field.

[0033] In the preparation method provided by the present invention, by first mixing the guaiac extract and the camellia extract, adjusting the pH value to 2-3, heating to 70-90°C and stirring for 0.5-3h, the interaction between the guaiac extract and the camellia extract can be promoted, thereby significantly improving the ultraviolet absorption capacity of the guaiac extract; and then titrating the prepared titration solution into a receiving solution containing calcium chloride to obtain sunscreen microspheres with a particle size of micrometer level and excellent comprehensive effect.

[0034] As a preferred embodiment of the preparation method of the present invention, the mass percentage of calcium chloride in the receiving solution is 0.2-1%.

[0035] Calcium chloride in an appropriate mass percentage range can help form a stable core-shell structure.

[0036] As a preferred embodiment of the preparation method of the present invention, the magnitude of the electric field is 10-30 kV.

[0037] As a preferred embodiment of the preparation method of the present invention, during the dropping process, the distance between the titration needle and the liquid surface of the receiving liquid is 5-20 cm.

[0038] As a preferred embodiment of the preparation method of the present invention, during the dropping process, the dropping speed is 0.01-1 mL / min.

[0039] Selecting the appropriate electric field size, the distance between the titration needle and the receiving liquid surface, and the dripping speed can help obtain micron-sized sunscreen microspheres, thereby improving the application of sunscreen microspheres in sunscreen lotions.

[0040] Preferably, in step (2), the mass ratio of the sum of the mass of the plant composition and sodium alginate to the mass of water is 1:(6.9-14.4).

[0041] In the third aspect of the present invention, the present invention provides the use of the sunscreen microspheres in the preparation of sunscreen products.

[0042] The sunscreen microspheres provided by the present invention are of micron level and have a high encapsulation rate. Since titanium dioxide and zinc oxide are encapsulated in a shell structure containing plant extracts and sodium alginate, they are not easy to penetrate into the skin. Therefore, on the basis of achieving their own anti-ultraviolet effect, they can also avoid irritation to the skin. In addition to achieving the anti-ultraviolet effect, the plant extracts in the shell structure also have good soothing and anti-inflammatory effects. Therefore, the sunscreen microspheres of the present invention can be widely used in the preparation of various sunscreen products.

[0043] In the fourth aspect of the present invention, a sunscreen lotion is provided, comprising the following components in mass percentage: 15-20% of the sunscreen microspheres of the present invention, 10-15% of a chemical sunscreen, 0.5-10% of an emollient, 0.1-5% of a film former, 5-12% of a humectant, 0.1-0.5% of a thickener, 0.5-2% of a preservative, 1-5% of an emulsifier, and the balance being water.

[0044] As a preferred embodiment of the sunscreen lotion of the present invention, the emollient includes at least one of dicaprylyl carbonate and diisopropyl sebacate.

[0045] As a preferred embodiment of the sunscreen lotion of the present invention, the film-forming agent includes at least one of trimethylsiloxysilicate and cyclopentasiloxane.

[0046] As a preferred embodiment of the sunscreen lotion of the present invention, the moisturizer includes at least one of glycerin, 1,3-butylene glycol, and 1,2-pentanediol.

[0047] As a preferred embodiment of the sunscreen lotion of the present invention, the thickener includes at least one of xanthan gum, carbomer, and sodium polyacrylate.

[0048] As a preferred embodiment of the sunscreen lotion of the present invention, the preservative includes at least one of p-hydroxyacetophenone and hexylene glycol.

[0049] As a preferred embodiment of the sunscreen lotion of the present invention, the emulsifier includes at least one of polyglyceryl-10 oleate, polysorbate 60, and polyglyceryl-3 diisostearate.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present invention wraps titanium dioxide and zinc oxide in appropriate mass parts in a plant extract and sodium alginate shell structure, and the selected plant extracts include guaiac wood extract, camellia extract, perilla leaf extract and immortelle flower extract, and the plant extracts cooperate with each other and with sodium alginate, titanium dioxide and zinc oxide, so that the obtained sunscreen microspheres have excellent anti-ultraviolet effect and are mild and non-irritating; at the same time, the obtained sunscreen microspheres also have excellent anti-inflammatory, anti-oxidation and post-sun soothing, skin barrier repair effects. In addition, the preparation method of the sunscreen microspheres provided by the present invention is simple to operate and is conducive to practical application. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 These are observation pictures before and after volunteers used the sunscreen lotion prepared in Application Example 1. DETAILED DESCRIPTION

[0053] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0054] Unless otherwise specified, the reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in the art; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch of raw materials.

[0055] Guaiac wood extract 1: Homemade, the preparation method includes the following steps:

[0056] The guaiac wood powder was added to a 40% by mass 1,3-butanediol aqueous solution (solid-liquid ratio of 1 g: 10 mL) and heated to 170° C. for extraction for 2 h, then placed in water for cooling, filtered, and the filtrate was collected and concentrated to obtain the guaiac wood extract 1;

[0057] Guaiac wood extract 2: Homemade, the preparation method includes the following steps:

[0058] The guaiac wood powder was added to a 70% by mass 1,3-butanediol aqueous solution (solid-liquid ratio of 1 g: 10 mL) and heated to 170°C for extraction for 2 hours, then placed in water for cooling, filtered, and the filtrate was collected and concentrated to obtain the guaiac wood extract 2;

[0059] Guaiac wood extract 3: Homemade, the preparation method includes the following steps:

[0060] The guaiac wood powder was added to a 40% by mass 1,3-butanediol aqueous solution (solid-liquid ratio of 1 g: 10 mL) and heated to 140°C for extraction for 2 hours, then placed in water for cooling, filtered, and the filtrate was collected and concentrated to obtain the guaiac wood extract 3;

[0061] Guaiac wood extract 4: Homemade, the preparation method includes the following steps:

[0062] The guaiac wood powder was added to a 40% by mass 1,3-butanediol aqueous solution (solid-liquid ratio of 1 g: 10 mL) and heated to 200°C for extraction for 2 hours, then placed in water for cooling, filtered, and the filtrate was collected and concentrated to obtain the guaiac wood extract 4;

[0063] Guaiac wood extract 5: Homemade, the preparation method includes the following steps:

[0064] The guaiac wood powder was added to a 40% by mass ethanol aqueous solution (solid-liquid ratio of 1 g: 10 mL) and refluxed for extraction for 2 h, then placed in water for cooling, filtered, and the filtrate was collected and concentrated to obtain the guaiac wood extract 5;

[0065] Camellia extract: Homemade, the preparation method includes the following steps:

[0066] Take commercially available camellia, dry to constant weight, crush, pass through a 60-mesh sieve, take the camellia powder and add it to 70°C water (solid-liquid ratio of 1g:10mL), heat and extract for 1h, filter, and concentrate the filtrate to a relative density of 1.05 to obtain a camellia extract;

[0067] Perilla leaf extract: homemade, the preparation method includes the following steps:

[0068] Take commercially available perilla leaves, dry them to constant weight, crush them, pass them through a 60-mesh sieve, take the perilla leaf powder and add it to 8 times the amount of water, stir and extract at 60°C for 30 minutes, filter and concentrate to obtain the perilla leaf extract;

[0069] Helichrysum flower extract: Homemade, the preparation method includes the following steps:

[0070] Take commercially available immortelle flowers, dry them to constant weight, crush them, pass them through a 60-mesh sieve, take the immortelle flower powder and add 10 times the amount of water, stir and extract at room temperature for 2 hours, filter and concentrate to obtain the immortelle flower extract;

[0071] Examples 1-8 and Comparative Examples 1-2

[0072] The embodiments and comparative examples of the present invention provide a sunscreen microsphere, the components (mass parts) of the sunscreen microsphere are shown in Table 1; wherein m1 is the sum of the masses of titanium dioxide and zinc oxide, and m2 is the sum of the masses of the plant extract and sodium alginate;

[0073] Table 1

[0074]

[0075]

[0076] The method for preparing the sunscreen microspheres provided in Example 1 comprises the following steps:

[0077] (1) mixing the guaiac extract and the camellia extract and adjusting the pH value to 2.5, then stirring at 80° C. for 2 h, cooling after the stirring and adjusting the pH value to 6, then adding the perilla leaf extract and the immortelle flower extract, and mixing evenly to obtain a plant composition;

[0078] (2) dispersing silicon dioxide and zinc oxide in water, adding the plant composition prepared in step (1) and sodium alginate (the mass ratio of the sum of the mass of the plant composition and sodium alginate to the mass of water is 1:10), and obtaining a titration solution;

[0079] (3) The titration solution is pumped into the titration needle and dripped into a receiving solution containing calcium chloride (the mass percentage of calcium chloride in the receiving solution is 0.5%). A 20 kV electric field is applied during the dripping process. The titration needle is 15 cm away from the liquid surface of the receiving solution. The dripping acceleration is 0.02 mL / min to obtain sunscreen microspheres.

[0080] The preparation methods of the sunscreen microspheres provided in Examples 2-8 and Comparative Examples 1-2 are consistent with that in Example 1.

[0081] Example 9

[0082] The embodiment of the present invention provides a sunscreen microsphere, wherein the only difference between the sunscreen microsphere and the embodiment 1 is that the guaiac extract 2 is used instead of the guaiac extract 1.

[0083] Example 10

[0084] The embodiment of the present invention provides a sunscreen microsphere, wherein the only difference between the sunscreen microsphere and embodiment 1 is that the guaiac extract 1 is replaced by the guaiac extract 3.

[0085] Embodiment 11

[0086] The embodiment of the present invention provides a sunscreen microsphere, wherein the only difference between the sunscreen microsphere and embodiment 1 is that the guaiac extract 1 is replaced by the guaiac extract 4.

[0087] Example 12

[0088] The embodiment of the present invention provides a sunscreen microsphere, wherein the only difference between the sunscreen microsphere and the embodiment 1 is that the guaiac extract 5 is used instead of the guaiac extract 1.

[0089] Embodiment 13

[0090] The embodiment of the present invention provides a sunscreen microsphere, and the only difference between the sunscreen microsphere and the embodiment 1 is step (3). Step (3) of this embodiment is:

[0091] The titration solution was pumped into a titration needle and dropped into a receiving solution containing calcium chloride (the mass percentage of calcium chloride in the receiving solution was 1%). A 30 kV electric field was applied during the dropping process. The titration needle was 5 cm away from the liquid surface of the receiving solution, and the dropping acceleration was 0.05 mL / min. Sunscreen microspheres were obtained.

[0092] Comparative Example 3

[0093] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that titanium dioxide is not added, and the amount of zinc oxide is supplemented.

[0094] Comparative Example 4

[0095] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that zinc oxide is not added, and the amount of titanium dioxide is supplemented.

[0096] Comparative Example 5

[0097] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that the guaiac extract is not added, the total number of plant extracts is kept unchanged, and the other three plant extracts are used to make up the difference in equal mass ratios.

[0098] Comparative Example 6

[0099] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that no camellia extract is added, the total number of plant extracts is kept unchanged, and the other three plant extracts are used to make up the difference in equal mass ratios.

[0100] Comparative Example 7

[0101] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that the perilla leaf extract is not added, the total number of plant extracts is kept unchanged, and the other three plant extracts are used to make up the difference in equal mass ratios.

[0102] Comparative Example 8

[0103] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that no immortelle extract is added, the total number of plant extracts is kept unchanged, and the other three plant extracts are used to make up the difference in equal mass ratios.

[0104] Comparative Example 9

[0105] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that the guaiac extract is replaced by the sugar cane extract.

[0106] Comparative Example 10

[0107] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that the camellia extract is replaced by the camellia extract.

[0108] Comparative Example 11

[0109] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that the Ginkgo biloba leaf extract is used instead of the Perilla frutescens leaf extract.

[0110] Comparative Example 12

[0111] The comparative example of the present invention provides a sunscreen microsphere, the only difference between the sunscreen microsphere and Example 1 is that the chrysanthemum extract is used instead of the immortelle extract.

[0112] Comparative Example 13

[0113] The comparative example of the present invention provides a sunscreen microsphere, and the only difference between the sunscreen microsphere and Example 1 is that the preparation method step (1) is different. The step (1) of this comparative example is:

[0114] The guaiac extract, the camellia extract, the perilla leaf extract and the immortelle flower extract are mixed evenly to obtain a plant composition.

[0115] Comparative Example 14

[0116] The comparative example of the present invention provides a sunscreen microsphere, and the only difference between the sunscreen microsphere and Example 1 is that the preparation method step (1) is different. The step (1) of this comparative example is:

[0117] The guaiac wood extract and the camellia extract were mixed and adjusted to a pH value of 1, followed by stirring at 80°C for 2 hours. After the stirring was completed, the mixture was cooled and the pH value was adjusted to 6. Then, the perilla leaf extract and the immortelle flower extract were added and mixed evenly to obtain a plant composition.

[0118] Comparative Example 15

[0119] The comparative example of the present invention provides a sunscreen microsphere, and the only difference between the sunscreen microsphere and Example 1 is that the preparation method step (1) is different. The step (1) of this comparative example is:

[0120] The guaiac wood extract and the camellia extract were mixed and adjusted to a pH value of 5, followed by stirring at 80°C for 2 hours. After the stirring was completed, the mixture was cooled and the pH value was adjusted to 6. Then, the perilla leaf extract and the immortelle flower extract were added and mixed evenly to obtain a plant composition.

[0121] Comparative Example 16

[0122] The comparative example of the present invention provides a sunscreen microsphere, and the only difference between the sunscreen microsphere and Example 1 is that the preparation method step (1) is different. The step (1) of this comparative example is:

[0123] The guaiac wood extract and the camellia extract were mixed and adjusted to a pH value of 5, followed by stirring at 60°C for 2 hours. After the stirring was completed, the mixture was cooled and the pH value was adjusted to 6. Then, the perilla leaf extract and the immortelle flower extract were added and mixed evenly to obtain a plant composition.

[0124] Comparative Example 17

[0125] The comparative example of the present invention provides a sunscreen microsphere, and the only difference between the sunscreen microsphere and Example 1 is that the preparation method step (1) is different. The step (1) of this comparative example is:

[0126] The guaiac wood extract and the camellia extract were mixed and the pH value was adjusted to 5, followed by stirring at 100°C for 2 hours. After the stirring was completed, the mixture was cooled and the pH value was adjusted to 6. Then, the perilla leaf extract and the immortelle flower extract were added and mixed evenly to obtain a plant composition.

[0127] Application examples 1-14, comparative application examples 1-17 and blank application examples

[0128] The application examples of the present invention provide a sunscreen lotion, the components (mass percentage) of the sunscreen lotion are shown in Table 2; wherein the sunscreen microspheres in application examples 1-13 correspond to the sunscreen microspheres prepared in embodiments 1-13, respectively, the sunscreen microspheres in comparative application examples 1-17 correspond to the sunscreen microspheres prepared in comparative examples 1-17, respectively, and the sunscreen microspheres in application example 14 are the sunscreen microspheres prepared in embodiment 1;

[0129] Table 2

[0130]

[0131]

[0132] The method for preparing the sunscreen lotion provided in Application Example 1 comprises the following steps:

[0133] The chemical sunscreen and emulsifier are mixed and heated to 80-90°C for homogenization, cooled to 40-50°C after homogenization, and then film formers and emollients are added to homogenize into a uniform oil phase, followed by adding moisturizers, thickeners and water at 20-30°C for emulsification, and after the emulsification is completed, sunscreen microspheres and preservatives are added and stirred to obtain a sunscreen product.

[0134] The preparation methods of the sunscreen lotions provided in Application Examples 1-14, Comparative Application Examples 1-17 and Blank Application Examples are consistent with those in Application Example 1.

[0135] Effect Example 1

[0136] The effects of the present invention are as follows: The performance of the sunscreen microspheres prepared in Examples 1-13 and Comparative Examples 1-17 is investigated, including the following aspects:

[0137] 1. Particle size test: The prepared sunscreen microspheres were placed under a microscope for observation, and the microsphere outlines were drawn using WZCamera software to calculate the diameter, which is the particle size of the microspheres. The results are shown in Table 3.

[0138] 2. Encapsulation rate test: calculated with titanium dioxide, refer to the method in the 2015 edition of the "Technical Specifications for Safety of Cosmetics":

[0139] 1) Preparation of standard curve: Accurately measure 5 mL of hydrochloric acid (ρ20 = 1.19 g / mL) in a 100 mL volumetric flask, accurately measure 0 mL, 0.1 mL, 0.2 mL, 0.5 mL, 1.0 mL, 2.0 mL, and 3.0 mL of 100 μg / mL titanium single element solution standard substance, and place them in 100 mL volumetric flasks respectively. Accurately add 10 mL of ascorbic acid solution (100 g / L), shake slightly, and place at room temperature for 5 minutes. Accurately add 10 mL of diantipyrine methane solution (8 g of diantipyrine methane is added to 10 mL of hydrochloric acid, diluted to 100 mL with deionized water, and shaken well), adjust to volume, shake well, and leave for 45 min. The concentrations of titanium in the titanium standard series solutions are 0 μg / mL, 0.1 μg / mL, 0.2 μg / mL, 0.5 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL, respectively.

[0140] 2) Sample determination: Take 5g of the prepared sunscreen microspheres, draw them up with a syringe and filter them with a 25μm organic phase filter membrane. Weigh 0.1g of the filtrate and the retentate respectively and place them in a 50mL porcelain crucible. At the same time, make a reagent blank. Slowly burn them on a low fire on an electric furnace until they are completely carbonized. Transfer them to a muffle furnace, gradually increase the temperature to 800℃, ash them for 2h, take them out, place them in a dryer, and cool them to room temperature. Carefully add 1.8g of potassium pyrosulfate powder to cover the sample as evenly and completely as possible. Cover the crucible, place it in a 550℃ muffle furnace to melt for about 10min, take it out and cool it. Measure 30mL of 10% sulfuric acid and place it in a crucible. Heat it on a low fire until the solution is clear, and carefully wash the melt on the crucible cover with the supernatant in the crucible and merge it into the crucible. Use a dropper to absorb the supernatant and transfer it to a 100mL volumetric flask. Add 5mL of sulfuric acid (ρ20=1.84g / mL) to the above crucible, heat until 2mL-3mL of sulfuric acid remains, remove it, suck out the supernatant with a pipette, and put it into a volumetric flask. Wash the crucible and lid with 10mL of 10% sulfuric acid three times, heat on low heat for a few minutes each time, and use a dropper to draw the supernatant into the same volumetric flask. Transfer 10mL of deionized water to wash the crucible and dropper, and put them into the volumetric flask. Cool, dilute to volume, and shake well. Accurately measure 5mL of hydrochloric acid into a 100mL volumetric flask, accurately transfer an appropriate amount of the above sample solution into the same volumetric flask, accurately add 10mL of ascorbic acid solution, shake slightly, and place at room temperature for 5min. Accurately add 10mL of diantipyrine methane solution, dilute to volume, shake well, and place for 45min to obtain the test solution;

[0141] 3) Measure the absorbance of the test solution, reagent blank, and standard solution at a wavelength of 388 nm, draw a standard curve, and calculate the titanium dioxide content according to the following formula:

[0142]

[0143] Where, ω is the content of titanium dioxide in the sample, %; ρ 1 is the mass concentration of titanium in the solution to be tested, μg / mL; ρ 0 is the mass concentration of titanium in the blank solution, μg / mL; V is the sample volume, mL; D is the dilution factor; m is the sample volume;

[0144] 4) The encapsulation efficiency is calculated as follows:

[0145]

[0146] In the formula, ω 1 is the titanium dioxide content in the retentate, %; ω 2 is the titanium dioxide content in the filtrate, %; m 1 is the mass of the retentate; m 2 is the mass of the filtrate; the results obtained are shown in Table 3;

[0147] 3. UVB absorption test: Take 1g of the sample and apply it evenly on 3M latex tape, place it in a 37℃ constant temperature box for 20min, take it out and attach it to the light-transmitting side of the quartz cuvette, and use a UV spectrophotometer to detect the UV absorption value in the 280-400nm band; obtain a UV absorption value every 10nm UV wavelength; the UV absorption value of a certain band is the arithmetic average UV absorption value of each point in the band; the results are shown in Table 3;

[0148] Table 3

[0149]

[0150] It can be seen from Table 3 that when the technical solution provided by the present invention is adopted, the particle size of the obtained product is between 41.01-47.71 μm, the encapsulation rate is between 77.71-89.10, and the UVB absorption value is above 1.601; it can be seen from Example 1 and the comparative example that when the technical solution of the present invention is not adopted, the encapsulation rate and UVB absorption value of the obtained product both show a significant downward trend.

[0151] Effect Example 2

[0152] The effects of the present invention are as follows: The performance of the sunscreen lotions prepared by application examples 1-14, comparative application examples 1-17 and blank application examples are explored, including the following aspects:

[0153] 1. SPF value test

[0154] The test was conducted in accordance with the requirements of the "Technical Specifications for Safety of Cosmetics" (2015 edition). 160 volunteers aged 32 to 60 were selected and divided into 32 groups, with 5 people in each group. The minimum erythema dose (MED) of the subjects' skin to ultraviolet radiation was predicted and the ultraviolet radiation dose was adjusted. A spot no less than 30 cm was selected on the back of the subject. 2 Normal skin area, (2.00±0.05)mg / cm 2 The test object or blank application example is evenly applied to the above area with the dosage of 1000mg / L, and then the irradiation dose is selected according to the specification requirements, and irradiation is carried out in three cases: 1) the test object is not applied to the subject's skin; 2) the control product (SPF value 16.1±2.4, prepared according to the standard formula of high SPF standard product P2 in the 2015 edition of the "Technical Specifications for Safety of Cosmetics"); 3) the test object is applied. Observe the experimental results after 24 hours, and record the MED values ​​in the three cases respectively.

[0155] SPF value calculation method: The SPF value of the test object or blank control protecting a single subject is expressed as follows:

[0156] SPFi = MED value of protected skin / MED value of unprotected skin;

[0157] Calculate the arithmetic mean of the SPF values ​​of all subjects protected by the tested object, retain one decimal place, and record it in Table 4;

[0158] 2. TEWL and a* value improvement test

[0159] Select volunteers aged 18-45 who have never used sunscreen products. Do not apply any skin care products on the day of the visit. After washing their faces, sit quietly in a constant temperature and humidity room at 21±1℃ and 50±10% for 30 minutes. Use Skin-Colorimeter CL400 to test the initial facial a* value; use the skin transepidermal water loss probe TM Hex (Courage+Khazaka) tests the initial facial TEWL value. 160 subjects with an initial facial a* value of more than 15 were screened and divided into 32 groups, 5 in each group, and the corresponding products were randomly applied to the entire face. TEWL and a* value tests were performed on days 7 and 14, and the improvement in TEWL and a* value of each volunteer on days 7 and 14 was analyzed. The improvement was represented by the improvement rate of each value, calculated as follows:

[0160] Improvement rate relative to the initial value = |(X 使用后 -X 使用前 ) / X 使用前 ×100%|; The calculated data are shown in Table 4;

[0161] Table 4

[0162]

[0163]

[0164] It can be seen from Table 4 that when the technical solution provided by the present invention is adopted, the obtained sunscreen lotion has a higher SPF value of more than 43.3; at the same time, the product prepared by the present invention also has good effects of repairing skin barrier, moisturizing, reducing skin red area, etc. Specifically, the TEWL improvement rate of the product prepared by the technical solution of the present invention is maintained at more than 10.53% in 14 days, and the a* value improvement rate is maintained at more than 11.45% in 14 days. Among them, the observation pictures of volunteers before and after using the sunscreen lotion in Application Example 1 are as follows Figure 1 As shown, from Figure 1 It can also be clearly seen that the sunscreen lotion provided by the present invention can effectively repair the skin while achieving basic sun protection.

[0165] Effect Example 3

[0166] The effect example of the present invention explores the applicability of the sunscreen lotion prepared in Application Example 1 to consumers with sensitive skin, specifically comprising the following steps: 30 Asian subjects with sensitive facial skin and recent sensitive skin symptoms are selected to participate in the test, and sunscreen lotion is distributed to them. Each subject is treated with 2 mg / cm 2 Appropriate amount of the product was applied on the face for 28 days for sensitive skin suitability test. Consumers completed questionnaire surveys on the improvement of indicators such as feeling of use, discomfort, tolerance, mildness and non-irritation. The results are shown in Table 5.

[0167] Table 5

[0168]

[0169] It can be seen from Table 5 that the sunscreen lotion prepared by the technical solution of the present invention is suitable for consumers with sensitive skin, and consumers with sensitive skin have a good usage experience.

[0170] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A high SPF soothing and repairing sunscreen microsphere suitable for sensitive skin, characterized in that: The sunscreen microspheres are of core-shell structure; The core layer includes titanium dioxide and zinc oxide; The shell layer comprises plant extracts and sodium alginate, wherein the plant extracts comprise guaiac extract, camellia extract, perilla leaf extract and immortelle flower extract; The ratio of the sum of the mass of the titanium dioxide and the zinc oxide to the sum of the mass of the plant extract and the sodium alginate is 1:(1.3-4.8); The mass ratio of guaiac extract, camellia extract, perilla leaf extract and immortelle extract is guaiac extract: camellia extract: perilla leaf extract: immortelle extract = (1-2): (3-5): (1-3): 1; The mass percentage of sodium alginate is 0.3-1% based on the total mass of the plant extract, titanium dioxide and zinc oxide; The mass ratio of titanium dioxide to zinc oxide is (0.5-3):1; The preparation method of the guaiac extract comprises the following steps: The guaiac wood powder is added to a 1,3-butanediol aqueous solution and heated to 160-180° C. for extraction for 1-4 hours, followed by cooling and filtering, collecting and concentrating the filtrate to obtain a guaiac wood extract.

2. The sunscreen microspheres according to claim 1, characterized in that: Satisfy at least one of the following: a. The preparation method of the camellia extract comprises the following steps: taking the crushed camellia, adding it to water, and then heating it to 60-80°C for extraction, filtering it after the extraction, collecting the filtrate and concentrating it to obtain a camellia extract; b. The preparation method of the perilla leaf extract comprises the following steps: taking the perilla leaf, crushing it, adding it to water, and then heating it to 50-70°C for extraction, filtering it after the extraction, collecting the filtrate and concentrating it to obtain the perilla leaf extract; c. The preparation method of the immortelle flower extract comprises the following steps: crushing the immortelle flower and adding it into water, stirring and extracting at room temperature, and filtering after the extraction to obtain the immortelle flower extract.

3. The method for preparing the sunscreen microspheres according to any one of claims 1 to 2, characterized in that: The preparation method comprises the following steps: (1) mixing the guaiac extract and the camellia extract and adjusting the pH value to 2-3, then stirring at 70-90° C. for 0.5-3 h, cooling after the stirring and adjusting the pH value to 5.5-6.5, then adding the perilla leaf extract and the immortelle flower extract, and mixing evenly to obtain a plant composition; (2) dispersing titanium dioxide and zinc oxide in water, adding the plant composition prepared in step (1) and sodium alginate, and mixing evenly to obtain a titration solution; (3) Drop the titration solution into a receiving solution containing calcium chloride to obtain sunscreen microspheres under the action of an electric field.

4. The preparation method according to claim 3, characterized in that: The mass percentage of calcium chloride in the receiving solution is 0.2-1%; And / or, the magnitude of the electric field is 10-30 kV; And / or, during the dropping process, the distance between the titration needle and the liquid surface of the receiving liquid is 5-20 cm; And / or, during the dripping process, the dripping speed is 0.01-1 mL / min.

5. Use of the sunscreen microspheres according to any one of claims 1 to 2 in the preparation of sunscreen products.

6. A sunscreen lotion, characterized in that: The sunscreen lotion comprises the following components in percentage by mass: 15-20% of the sunscreen microspheres as claimed in any one of claims 1 to 2, 10-15% of a chemical sunscreen, 0.5-10% of an emollient, 0.1-5% of a film former, 5-12% of a humectant, 0.1-0.5% of a thickener, 0.5-2% of a preservative, 1-5% of an emulsifier, and the balance is water.

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