Skin care composition for repairing sensitive skin and preparation method thereof

Abstract

The invention provides a skin care composition for repairing sensitive skin and a preparation method thereof, and the composition comprises the following components in percentage by mass: 1-5% of zinc oxide, 0.5-2% of a vitamin E derivative, 1-3% of a centella asiatica extract, 3-8% of a nano emulsion, 0.5-3% of an artemisia argyi extract, 10-20% of natural oil, 5-15% of a humectant, 2-6% of an emulsifier and the balance of water. And 0.5-1% of a preservative and the balance of deionized water, totaling 100%. The preparation method comprises the following five steps: pretreating each component, and melting at a proper temperature for later use; secondly, preparing a nano-emulsion and controlling the particle size to be less than 100 nanometers; then, mixing and stirring the components under the condition of 45-55 DEG C to form an emulsifying system; then, carrying out homogenization treatment through a high-speed homogenizer; finally, cooling the mixture to room temperature and keeping stirring to prevent layering; according to the skin care composition, through the synergistic effect of multiple repairing components, the skin barrier is effectively repaired, inflammation is relieved, and the moisturizing effect of the skin is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of skin care products, and in particular to a skin care composition for repairing sensitive skin and a preparation method thereof. Background Art

[0002] With the increase of environmental pollution and life pressure, more and more people are facing the problem of skin sensitivity. The characteristics of sensitive skin include damaged skin barrier function, which is easily affected by external temperature changes, ultraviolet radiation, and chemical stimulation, and manifests as symptoms such as redness, tingling, itching and dryness. There are many kinds of skin care products on the market for repairing sensitive skin, but most products only focus on a single moisturizing or soothing effect, and cannot fundamentally repair the skin barrier. In addition, some ingredients may further irritate the skin.

[0003] In the prior art, although there are a variety of skin care product additives on the market that are used to repair sensitive skin, such as moisturizing ingredients such as hyaluronic acid and glycerin, or plant extracts such as aloe vera for soothing the skin, these products mainly focus on improving the hydration state of the skin or relieving inflammatory reactions in the short term, but lack the ability to fundamentally repair damaged skin. In addition, when these additives are used alone, their anti-inflammatory and antioxidant effects are limited, and they cannot cope with a variety of sensitive symptoms caused by damaged skin barrier function;

[0004] To this end, a skin care composition for repairing sensitive skin and a preparation method thereof are proposed. Summary of the invention

[0005] In view of this, the present invention provides a skin care composition for repairing sensitive skin and a preparation method thereof, so as to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial choice.

[0006] The technical solution of the present invention is implemented as follows: a skin care composition for repairing sensitive skin, characterized in that it includes the following ingredients by mass percentage: zinc oxide: 1-5%, vitamin E derivative: 0.5-2%, Centella asiatica extract: 1-3%, nanoemulsion: 3-8%, artemisia annua extract: 0.5-3%, natural oil: 10-20%, moisturizer: 5-15%, emulsifier: 2-6%, preservative: 0.5-1%, deionized water: the remaining amount is up to 100%.

[0007] The above ingredients are uniformly mixed and treated with nano-ultrasonic emulsification to form a stable emulsified system for repairing and improving the symptoms of sensitive skin;

[0008] The vitamin E derivative is selected from one or two of tocopherol acetate, tocopherol acetate and tocopherol succinate, and the content accounts for 0.5-2% of the composition;

[0009] The natural oil is selected from one or two of beeswax, jojoba oil, coconut oil, avocado oil and olive oil, and the content accounts for 10-20% of the composition;

[0010] The moisturizing agent is selected from one or two of glycerin, sodium hyaluronate, propylene glycol and butylene glycol, and the content accounts for 5-15% of the composition;

[0011] The nanoemulsion contains paeoniflorin and asiaticaoside, and is prepared by ultrasonic emulsification, and the total content of the nanoemulsion accounts for 3-8% of the composition;

[0012] The emulsifier is selected from one or two of ceteth-20, steareth-21 and polyglyceryl-10 laurate, accounting for 2-6% of the composition;

[0013] The present invention also provides a method for preparing a skin care composition for repairing sensitive skin, comprising the following preparation steps:

[0014] Step 1, weighing 1-5% of the total amount of the composition of zinc oxide, performing micronization, weighing 0.5-2% of the vitamin E derivative, weighing 1-3% of the Centella asiatica extract, weighing 10-20% of the natural oil, and melting them at 45-55° C. for later use, and weighing 0.5-3% of the Artemisia argyi extract for later use;

[0015] Step 2: Using paeoniflorin and asiaticaoside as active ingredients, a nanoemulsion is prepared at a ratio of 3-8% of the total amount of the composition, and the active ingredients are dissolved in a solvent by ultrasonic emulsification (the solvent of the active ingredient is ethanol or propylene glycol, and 0.1-0.5% of a surfactant is added during ultrasonic emulsification, and the total treatment time of the ultrasonic equipment is extended to 20-30 minutes, so that the particle size is 50-100 nanometers), and the ultrasonic equipment is used for treatment for 10-20 minutes at a temperature range of 20-30° C., so that the particle size of the emulsion is controlled to be below 100 nanometers;

[0016] Step 3, stirring the melted natural oil at a temperature of 45-55°C, slowly adding zinc oxide, vitamin E derivatives and Centella asiatica extract, maintaining the stirring speed at 300-500 rpm, and continuously stirring for 10-15 minutes until a uniform emulsified mixture is formed, then slowly adding the nanoemulsion to the emulsified mixture at the same temperature, and continuing to stir for 5-10 minutes, then adding 5-15% of the moisturizer and 2-6% of the emulsifier according to the total amount of the composition, and continuing to stir for 10 minutes to form a stable emulsified system;

[0017] Step 4: Process the uniformly mixed emulsified system through a high-speed homogenizer (add 0.05-0.2% antioxidant, stir continuously for 5-10 minutes at room temperature, and then filter through a 0.2 micron filter membrane to remove fine particles), control the homogenization pressure at 20-40 MPa, and process for 5-10 minutes to make the active ingredients more evenly distributed in the system;

[0018] Step 5: The homogenized mixture is rapidly cooled to room temperature (20-25° C.), and the stirring speed is maintained at 100-200 rpm during the cooling process to prevent stratification.

[0019] The embodiment of the present invention has the following advantages due to the adoption of the above technical solution:

[0020] First, the present invention combines a variety of repair ingredients to achieve multiple skin barrier repairs, enhance the skin's barrier function, effectively reduce water loss, enhance the skin's protective ability, and improve sensitive skin symptoms. Secondly, the formula combines anti-inflammatory and antioxidant ingredients such as artemisia extract, vitamin E derivatives and Centella asiatica glycoside to inhibit skin inflammatory reactions and reduce free radical damage to the skin, thereby reducing symptoms of redness, swelling, itching and tingling.

[0021] 2. The present invention adopts nano-emulsification technology to make the particle size of active ingredients smaller and more evenly distributed, thereby improving the stability and transdermal absorption effect of the ingredients, promoting the effective ingredients to penetrate deeply into the dermis, thereby enhancing the skin care effect. In addition, the hyaluronic acid and natural oils in the composition can continuously improve the hydration state of the skin, enhance the softness and smoothness of the skin, and further relieve dryness and discomfort.

[0022] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0025] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] Example 1

[0028] like Figure 1 As shown, this embodiment discloses a skin care composition for repairing sensitive skin and a preparation method thereof, wherein the components and steps are specifically as follows:

[0029] By mass percentage, the skin care composition comprises the following ingredients (total amount is 100%):

[0030] Zinc oxide: 3%, Vitamin E derivative (tocopheryl acetate): 1%, Centella asiatica extract: 2%

[0031] Nanoemulsion (containing paeoniflorin and asiatica glycoside): 5%, Artemisia argyi extract: 1%, natural oil (a mixture of beeswax and jojoba oil, beeswax accounts for 7% of the total amount, jojoba oil accounts for 6% of the total amount): 13%, moisturizer (glycerin): 10%, emulsifier (cetyl alcohol polyether-20): 4%, preservative (phenoxyethanol): 0.7%, deionized water: 60.3%;

[0032] The specific steps of the preparation method of this composition are as follows:

[0033] Step 1: Weigh 3% zinc oxide and perform micronization to improve its dispersibility in the composition and ensure uniform distribution; weigh 1% vitamin E derivative (tocopherol acetate) and store it under low temperature conditions to prevent oxidation and activity reduction; weigh 2% Centella asiatica extract and store it under refrigerated conditions to prevent degradation of active ingredients; melt the natural oil mixture (7% beeswax and 6% jojoba oil) at 45-55°C and keep stirring until it is completely melted for use; weigh 1% mugwort extract and set it aside for use in subsequent steps;

[0034] Step 2: Using paeoniflorin and asiaticaoside as active ingredients, a nanoemulsion accounting for 5% of the total amount of the composition is prepared; the active ingredients are dissolved in an appropriate amount of ethanol, and 0.3% of a surfactant (polysorbate-20) is added, and the mixture is stirred and mixed evenly; then, an ultrasonic device is used for treatment for 25 minutes within a temperature range of 20-30° C., and the ultrasonic frequency is controlled at about 40 kHz to ensure that the emulsion particle size is controlled between 50 and 100 nanometers, thereby enhancing the transdermal absorption effect and bioavailability;

[0035] Step 3: Stir the melted beeswax and jojoba oil mixture at 45-55°C, slowly add 3% zinc oxide, and continue stirring until uniformly dispersed; then add 1% tocopherol acetate and 2% Centella asiatica extract in sequence, keep the stirring speed at 400 rpm for 12 minutes to ensure that all ingredients are evenly distributed in the base oil phase; next, at the same temperature, slowly add the previously prepared 5% nanoemulsion to the emulsified mixture, continue stirring for 7 minutes to stabilize the system; then, add 10% glycerin and 4% ceteth-20, and stir again for 10 minutes to form a stable emulsified system;

[0036] Step 4: The stirred and mixed emulsified system is processed by a high-speed homogenizer, the homogenization pressure is controlled at 30 MPa, and the processing time is 7 minutes; this process can make the active ingredients more evenly distributed in the emulsified system, and improve the stability and performance of the composition;

[0037] Step 5: After the homogenization treatment is completed, 0.1% rosemary extract is added to the mixture as an antioxidant, and stirring is continued for 7 minutes at room temperature 20-25°C to ensure that the antioxidant is evenly distributed in the emulsified system; then, the mixture is quickly cooled to room temperature, and the stirring speed is maintained at 150 rpm during the cooling process to prevent stratification; after cooling, the mixture is filtered through a 0.2 micron filter membrane to remove the fine particles present.

[0038] Example 2

[0039] The difference from Example 1 is that the components and steps are as follows:

[0040] By mass percentage, the skin care composition comprises the following ingredients (total amount is 100%):

[0041] Zinc oxide: 4%, vitamin E derivative (tocopheryl acetate): 1.5%, Centella asiatica extract: 3%, nanoemulsion (containing paeoniflorin and asiatica glycoside): 6%, artemisia extract: 2%, natural oil (a mixture of avocado oil and olive oil, avocado oil accounts for 8% of the total amount, olive oil accounts for 5% of the total amount): 13%, moisturizer (sodium hyaluronate): 7%, emulsifier (stearyl alcohol polyether-21): 3%, preservative (phenoxyethanol): 0.8%, deionized water: 59.7%;

[0042] The specific steps of the preparation method of this composition are as follows:

[0043] Step 1: Weigh 4% of zinc oxide and perform micronization to ensure that it is evenly dispersed in the composition; weigh 1.5% of vitamin E derivative (tocopherol acetate) and store it under low temperature conditions to prevent oxidation and activity reduction; weigh 3% of Centella asiatica extract and refrigerate it to maintain its activity; melt the natural oil mixture (8% avocado oil and 5% olive oil) at 45-55°C and stir until uniform; weigh 2% of Artemisia argyi extract and set aside;

[0044] Step 2: Using paeoniflorin and asiaticaside as active ingredients, a nanoemulsion accounting for 6% of the total amount of the composition is prepared; the active ingredients are dissolved in propylene glycol, and 0.2% of a surfactant (such as polysorbate-80) is added, and ultrasonic emulsification treatment is performed at 20-30° C. for 30 minutes, and the ultrasonic frequency is controlled at about 45 kHz, so that the particle size of the nanoemulsion is controlled between 80 and 100 nanometers to improve the transdermal absorption ability of the ingredients;

[0045] Step 3: Stir the melted avocado oil and olive oil mixture at 45-55°C, slowly add zinc oxide, and continue stirring until evenly dispersed; then add 1.5% tocopherol acetate and 3% Centella asiatica extract in sequence, keep the stirring speed at 350 rpm, stir for 15 minutes, and ensure that all ingredients are evenly mixed; then, slowly add 6% nanoemulsion to the above mixture, and continue stirring for 7 minutes to ensure even distribution; then, add 7% sodium hyaluronate and 3% steareth-21, and continue stirring for 10 minutes to form a stable emulsified system;

[0046] Step 4: The stirred emulsified system is processed by a high-speed homogenizer, the homogenization pressure is controlled at 35 MPa, and the processing time is 8 minutes, so as to further improve the uniform distribution of the active ingredients in the system and improve the stability and efficacy of the composition;

[0047] Step 5: After homogenization, add 0.1% rosemary extract as an antioxidant to the mixture and stir at room temperature (20-25°C) for 5 minutes to ensure that the antioxidant is evenly distributed; then, quickly cool the mixture to 20-25°C, and keep the stirring speed at 100 rpm during the cooling process to prevent stratification; after cooling, filter the mixture using a 0.2 micron filter membrane to remove any fine particles; finally, fill and seal the package to ensure the purity and stability of the product.

[0048] Example 3

[0049] The difference from Examples 1 and 2 is that the components and steps are as follows:

[0050] By mass percentage, the skin care composition comprises the following ingredients (total amount is 100%):

[0051] Zinc oxide: 2%, vitamin E derivative (tocopheryl succinate): 0.8%, Centella asiatica extract: 1.5%, nanoemulsion (containing paeoniflorin and asiatica glycoside): 4%, Artemisia argyi extract: 0.7%, natural oil (a mixture of beeswax and coconut oil, beeswax accounts for 6% of the total amount, coconut oil accounts for 7% of the total amount): 13%, moisturizer (a mixture of propylene glycol and sodium hyaluronate, propylene glycol accounts for 5%, sodium hyaluronate accounts for 2%): 7%, emulsifier (polyglyceryl-10 laurate): 5%, preservative (phenoxyethanol): 0.9%, deionized water: 65.1%;

[0052] The specific steps of the preparation method of this composition are as follows:

[0053] Step 1: Weigh 2% zinc oxide and perform micronization to ensure uniform particle distribution; weigh 0.8% vitamin E derivative (tocopherol succinate) and store it in a low temperature environment to prevent oxidative degradation; weigh 1.5% Centella asiatica extract and store it in a refrigerated environment; melt the natural oil mixture (6% beeswax and 7% coconut oil) at 45-55°C and stir until completely uniform; weigh 0.7% mugwort extract and set aside;

[0054] Step 2: Using paeoniflorin and asiaticaside as active ingredients, preparing a nanoemulsion accounting for 4% of the total amount of the composition; using propylene glycol as a solvent, adding 0.2% polysorbate-20 as a surfactant, performing ultrasonic emulsification treatment at a temperature of 25°C for 20 minutes, maintaining the ultrasonic frequency at 35kHz, so that the particle size of the nanoemulsion is controlled between 80-100 nanometers, ensuring efficient transdermal absorption of the active ingredients;

[0055] Step 3: Stir the melted beeswax and coconut oil mixture at 50°C, slowly add zinc oxide, and continue stirring to ensure uniform dispersion; then add 0.8% tocopherol succinate and 1.5% Centella asiatica extract in sequence, keep the stirring speed at 300 rpm, and stir for 10 minutes; then, gradually add 4% nanoemulsion to the mixture, and continue stirring for 5 minutes to ensure the uniformity of the emulsification system; then, add 7% of the moisturizer mixture (propylene glycol and sodium hyaluronate), and 5% of polyglyceryl-10 laurate emulsifier, and stir again for 10 minutes to form a stable emulsification system;

[0056] Step 4: The mixed emulsified system is processed by a high-speed homogenizer, the homogenization pressure is set to 25 MPa, and the processing time is 6 minutes; this step helps to improve the uniformity and stability of the composition and make the active ingredients better distributed in the emulsified system;

[0057] Step 5: After homogenization, add 0.1% rosemary extract as an antioxidant and continue stirring at room temperature for 5 minutes to ensure that the antioxidant is evenly distributed in the system; then, cool the mixture to 20-25°C, and keep the stirring speed at 120 rpm during the cooling process to avoid stratification; after cooling, filter the mixture using a 0.2 micron filter membrane to remove any tiny particles, and finally fill and seal the package to ensure the purity and stability of the product.

[0058] Example 4

[0059] Different from Examples 1, 2 and 3, the components and steps are as follows:

[0060] By mass percentage, the skin care composition comprises the following ingredients (total amount is 100%):

[0061] Zinc oxide: 1.5%, vitamin E derivative (tocopheryl acetate): 1%, Centella asiatica extract: 2.5%, nanoemulsion (containing paeoniflorin and asiaticoside): 7%, Artemisia argyi extract: 1.2%, natural oil (a mixture of avocado oil and olive oil, avocado oil accounts for 8%, olive oil accounts for 5%): 13%, moisturizer (a mixture of sodium hyaluronate and glycerin, sodium hyaluronate accounts for 4%, glycerin accounts for 3%): 7%, emulsifier (cetyl alcohol polyether-20): 4%, preservative (phenoxyethanol): 0.6%, deionized water: 61.2%;

[0062] The specific steps of the preparation method of this composition are as follows:

[0063] Step 1: Weigh 1.5% of zinc oxide and perform micronization to ensure uniform dispersion; weigh 1% of vitamin E derivative (tocopheryl acetate) and store it in a low temperature environment to maintain its activity; weigh 2.5% of Centella asiatica extract and store it in a refrigerator for later use; melt the natural oil mixture (8% avocado oil and 5% olive oil) at 45-55°C and continue stirring until it is completely uniform; weigh 1.2% of Artemisia argyi extract and set it aside;

[0064] Step 2: Using paeoniflorin and asiaticaoside as active ingredients, a nanoemulsion accounting for 7% of the total amount of the composition is prepared; the active ingredients are dissolved in ethanol, 0.3% of a surfactant (such as polysorbate-20) is added, and ultrasonic emulsification is performed at 20-30° C. for 30 minutes, the ultrasonic frequency is controlled at 40 kHz, and the particle size of the nanoemulsion is controlled at 50-80 nanometers to enhance its transdermal absorption ability;

[0065] Step 3: Stir the melted avocado oil and olive oil mixture at 50°C, slowly add zinc oxide, and stir until evenly dispersed; then add 1% tocopherol acetate and 2.5% Centella asiatica extract in sequence, keep the stirring speed at 350 rpm, and continue stirring for 12 minutes until the mixture is evenly mixed; then, gradually add 7% nanoemulsion to the above mixture, and continue stirring for 8 minutes to ensure that the emulsified system is stable; then, add 7% of the moisturizer mixture (sodium hyaluronate and glycerin) and 4% of ceteth-20, and stir for another 10 minutes to form a stable emulsified system;

[0066] Step 4: The uniformly mixed emulsified system is processed by a high-speed homogenizer, the homogenization pressure is set to 30 MPa, and the processing time is 8 minutes to ensure uniform distribution of the active ingredients and improve the stability and absorption effect of the composition;

[0067] Step 5: After homogenization, add 0.1% rosemary extract as an antioxidant and continue stirring at room temperature for 5 minutes to ensure that the antioxidant is evenly distributed; then, cool the mixture to 20-25°C, and keep the stirring speed at 120 rpm during the cooling process to prevent stratification; after cooling, filter the mixture using a 0.2 micron filter membrane to remove any tiny particles, and finally fill and seal the package to ensure the purity and stability of the product.

[0068] The skin care composition prepared by the method of Examples 1-4 above can effectively repair sensitive skin, enhance skin barrier function, reduce skin redness, dryness and other sensitive symptoms, and significantly improve the moisture content and smoothness of the skin.

[0069] Test example

[0070] This test example evaluates the effects of skin care compositions of four different embodiments on repairing sensitive skin;

[0071] Multiple skin index tests including transepidermal water loss, skin hydration status, redness and irritation symptom scores, and skin elasticity (R7 value) were used to demonstrate the performance of the composition in improving skin conditions;

[0072] 1. Test methods

[0073] Before the start of the trial, eligible volunteers were recruited to ensure that their skin type was sensitive. The volunteers underwent skin condition assessment before the trial. Each participant recorded basic data at baseline (week 0) and was then randomly assigned to four embodiment groups, each group using a different skin care composition.

[0074] The composition of each example was prepared according to the preparation method of Example 1 to Example 4. The volunteers were required to follow the same daily skin care process during the entire trial to ensure the comparability of the results. At the 4th and 8th weeks, the volunteers returned for follow-up tests to evaluate the skin improvement effect of the skin care composition on the skin.

[0075] The test includes using a transepidermal water loss instrument to measure the TEWL value to evaluate the skin barrier function; using a hydration status tester to determine the stratum corneum moisture value; evaluating redness and irritation symptoms based on a 0-10 point scoring system; and measuring skin elasticity (R7 value) using a skin elasticity meter. All data are measured by professional instruments and statistically analyzed to evaluate the effects of different embodiments.

[0076] 2. Test indicators

[0077] Transepidermal water loss: Use an instrument to measure the evaporation rate of water on the skin surface to assess the integrity of the skin barrier function, as shown in Table 1 below;

[0078] Table 1. Transepidermal water loss (TEWL) test results

[0079] Example Week 0 (Baseline) Week 4 Week 8 TEWL reduction (week 8) Example 1 20.5±1.2 15.4±1.1 11.8±0.9 42.4％ Example 2 21.3±1.3 14.9±1.0 11.5±0.8 46.0％ Example 3 22.1±1.4 14.2±1.1 10.6±0.7 52.0％ Example 4 21.8±1.3 13.8±0.9 10.3±0.6 52.8％

[0080] Transepidermal water loss is an indicator for evaluating skin barrier function. The lower the value, the stronger the skin's moisturizing ability and the more complete the barrier function. In this transepidermal water loss test, the transepidermal water loss values ​​of all embodiments were significantly reduced after 8 weeks. The transepidermal water loss reduction in Example 4 was the highest, reaching 52.8%, which shows that the composition is effective in improving skin barrier function, helping to reduce water loss, thereby enhancing the skin's moisturizing ability.

[0081] Skin hydration status: The hydration status of the skin is reflected by measuring the moisture value of the stratum corneum, as shown in Table 2 below;

[0082] Table 2. Skin hydration status test results

[0083] Example Week 0 (Baseline) Week 4 Week 8 Water content increase (week 8) Example 1 38.2±2.0 49.3±2.1 55.8±2.0 46.1％ Example 2 37.8±1.9 50.1±2.3 55.5±1.9 46.8％ Example 3 39.0±2.1 52.4±2.4 57.5±2.3 47.4％ Example 4 38.5±2.0 51.9±2.2 58.1±2.1 50.9％

[0084] The skin hydration status is evaluated by the stratum corneum moisture value, which reflects the overall moisture content of the skin. This data shows that all examples are improved after 8 weeks, and Example 4 has the highest increase in moisture, reaching 50.9%, which shows that the composition effectively enhances the skin's hydration capacity, improves the skin's softness and smoothness, and is suitable for use on sensitive skin.

[0085] Redness and irritation symptom scoring: Based on the subjective feelings of the volunteers, a 0-10 point scoring system was used to evaluate the degree of redness and irritation of the skin, as shown in Table 3 below;

[0086] Table 3. Redness, swelling and irritation symptom scores (0-10 points)

[0087] Example Week 0 (Baseline) Week 4 Week 8 Reduction in symptom scores (week 8) Example 1 6.8±0.8 4.3±0.6 3.0±0.5 55.9％ Example 2 7.0±0.9 4.5±0.7 2.9±0.4 58.6％ Example 3 6.7±0.7 4.1±0.5 2.6±0.3 61.2％ Example 4 7.1±0.8 4.2±0.6 2.5±0.3 64.8％

[0088] This indicator measures the comfort of the skin through the degree of redness, swelling and irritation self-assessed by the volunteers. The results show that the redness and irritation symptom scores of all examples were significantly reduced after 8 weeks, reflecting the effectiveness of the skin care composition in improving sensitive skin. The score of Example 4 was reduced the most, from 7.1 points at the baseline to 2.0 points, a decrease of 71.8%, showing its excellent effect in reducing skin redness and irritation. Example 3 also showed a significant improvement effect, with a score reduction of 67.2%, from 6.7 points at the baseline to 2.2 points. The reduction in the redness and swelling scores of Examples 1 and 2 after 8 weeks also reached 60.3% and 64.3%, respectively, and they also have a good effect in repairing sensitive skin.

[0089] Skin elasticity (R7 value): Measured by a skin elasticity meter, providing important data on skin elasticity.

[0090] Table 4. Skin elasticity (R7 value) test results

[0091] Example Week 0 (Baseline) Week 4 Week 8 Elasticity improvement (week 8) Example 1 58.2±3.1 68.9±3.3 76.5±3.2 31.4％ Example 2 57.5±3.0 69.3±3.2 77.2±3.1 34.3％ Example 3 56.8±2.9 71.1±3.4 79.2±3.3 39.4％ Example 4 57.0±3.0 71.5±3.5 81.2±3.4 42.4％

[0092] Skin elasticity is an indicator of skin health and is used to evaluate the firmness and flexibility of the skin. All examples were improved after 8 weeks, among which Example 4 had the highest elasticity improvement of 42.4%, which shows that the composition effectively enhances skin elasticity, makes the skin firmer, and helps to improve the overall appearance of the skin.

[0093] The test results of the four embodiments show that each composition shows a positive effect in improving skin condition, especially Example 4, which shows better repairing and moisturizing effects due to its rich moisturizing ingredients and repairing ingredients.

[0094] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A skin care composition for repairing sensitive skin, characterized in that: The composition comprises the following ingredients by mass percentage: zinc oxide: 1-5%, vitamin E derivative: 0.5-2%, centella asiatica extract: 1-3%, nanoemulsion: 3-8%, artemisia argyi extract: 0.5-3%, natural oil: 10-20%, moisturizer: 5-15%, emulsifier: 2-6%, preservative: 0.5-1%, and deionized water: the remaining amount to 100%. The above ingredients are uniformly mixed and subjected to nano-ultrasonic emulsification treatment to form a stable emulsified system for repairing and improving the symptoms of sensitive skin.

2. A skin care composition for repairing sensitive skin according to claim 1, characterized in that: The vitamin E derivative is selected from one or two of tocopherol acetate, tocopherol acetate and tocopherol succinate, and the content of the vitamin E derivative accounts for 0.5-2% of the composition.

3. A skin care composition for repairing sensitive skin according to claim 1, characterized in that: The natural oil is selected from one or two of beeswax, jojoba oil, coconut oil, avocado oil and olive oil, and the content accounts for 10-20% of the composition.

4. A skin care composition for repairing sensitive skin according to claim 1, characterized in that: The moisturizing agent is selected from one or two of glycerin, sodium hyaluronate, propylene glycol and butylene glycol, and the content of the moisturizing agent accounts for 5-15% of the composition.

5. A skin care composition for repairing sensitive skin according to claim 1, characterized in that: The nanoemulsion contains paeoniflorin and asiaticaoside and is prepared by ultrasonic emulsification. The total content of the nanoemulsion accounts for 3-8% of the composition.

6. A skin care composition for repairing sensitive skin according to claim 1, characterized in that: The emulsifier is selected from one or two of ceteth-20, steareth-21 and polyglyceryl-10 laurate, accounting for 2-6% of the composition.

7. A method for preparing a skin care composition for repairing sensitive skin according to any one of claims 1 to 6, characterized in that: The method comprises the following preparation steps: Step 1, weighing 1-5% of the total amount of the composition of zinc oxide, performing micronization, weighing 0.5-2% of the vitamin E derivative, weighing 1-3% of the Centella asiatica extract, weighing 10-20% of the natural oil, and melting them at 45-55° C. for later use, and weighing 0.5-3% of the Artemisia argyi extract for later use; Step 2, using paeoniflorin and asiaticaoside as active ingredients, preparing a nanoemulsion at a ratio of 3-8% of the total amount of the composition, dissolving the active ingredients in a solvent by ultrasonic emulsification, and treating with an ultrasonic device for 10-20 minutes at a temperature range of 20-30° C., so that the particle size of the emulsion is controlled to be below 100 nanometers; Step 3, stirring the melted natural oil at a temperature of 45-55°C, slowly adding zinc oxide, vitamin E derivatives and Centella asiatica extract, maintaining the stirring speed at 300-500 rpm, and continuously stirring for 10-15 minutes until a uniform emulsified mixture is formed, then slowly adding the nanoemulsion to the emulsified mixture at the same temperature, and continuing to stir for 5-10 minutes, then adding 5-15% of the moisturizer and 2-6% of the emulsifier according to the total amount of the composition, and continuing to stir for 10 minutes to form a stable emulsified system; Step 4: Process the uniformly mixed emulsified system through a high-speed homogenizer, with the homogenization pressure controlled at 20-40 MPa for 5-10 minutes, so that the active ingredients are more evenly distributed in the system; Step 5: The homogenized mixture is rapidly cooled to room temperature (20-25° C.), and the stirring speed is maintained at 100-200 rpm during the cooling process to prevent stratification.

8. The method for preparing a skin care composition for repairing sensitive skin according to claim 7, characterized in that: In the preparation of the nanoemulsion in step 2, the solvent of the active ingredient is ethanol or propylene glycol, and 0.1-0.5% of a surfactant is added during ultrasonic emulsification. The total ultrasonic treatment time is extended to 20-30 minutes to make the particle size 50-100 nanometers.

9. The method for preparing a skin care composition for repairing sensitive skin according to claim 7, characterized in that: After the homogenization treatment in step 4, 0.05-0.2% of an antioxidant is added and stirred for 5-10 minutes at room temperature, and then filtered through a 0.2 micron filter membrane to remove fine particles.

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