Intelligent response skin care composition as well as preparation method and application thereof

Abstract

The invention relates to an intelligent response skin care composition as well as a preparation method and application thereof. The composition comprises freeze-dried phytoestrogen powder, poly (N-isopropylacrylamide), chitosan, a humectant and vitamin C, and the water dispersibility and skin absorbability of the composition are remarkably improved. Poly (N-isopropylacrylamide) and chitosan respectively endow the composition with temperature and pH response characteristics, and can intelligently slowly release and regulate and control release of active ingredients according to skin environment changes (such as high temperature and sweat pH rise), thereby achieving the effects of long-acting moisturizing, oil resistance, aging resistance and the like. Experiments show that the moisturizing rate of the composition in a high-temperature environment within 3 hours exceeds 65%, the wrinkle reduction rate within 3 months reaches 41.2%, the composition is suitable for facial masks, essence and other dosage forms, the problem that the skin barrier function is reduced due to high temperature in summer is solved, and the composition has safety and precise skin care effects.

Description

Technical Field

[0001] The invention belongs to the technical field of skin care products, and in particular relates to an intelligent skin care composition containing phytoestrogen components, which can improve skin wrinkles and skin moisture retention. Background Art

[0002] As we age, our skin undergoes a series of physiological changes that lead to the formation of wrinkles and a decrease in skin elasticity. These changes are mainly caused by a combination of endogenous and exogenous factors. Endogenous factors include aging and menopause, which can lead to a decrease in collagen and elastic fibers in the skin, causing the skin to lose elasticity and firmness. In addition, the constant relaxation and contraction of muscles can also exacerbate the formation of wrinkles. Exogenous factors such as environmental pollutants and stress can further accelerate the aging process of the skin. Specifically, as the skin ages, the number of keratinocytes and fibroblasts decreases, and the ability to synthesize collagen decreases, leading to the destruction of the skin structure. At the same time, an increase in melanin signaling can also lead to an increase in blemishes, freckles, and spots. In particular, the decline in estrogen levels after aging significantly accelerates skin aging, which is manifested as a decrease in skin thickness, reduced elasticity, and an increase in wrinkles.

[0003] In recent years, phytoestrogens have gradually become a research hotspot in the field of anti-aging skin care due to their weak estrogenic activity and safety. Phytoestrogens are a class of natural compounds with estrogen-like activity found in plants. They can work by binding to estrogen receptors or interacting with major enzymes related to hormone production. Compared with the direct use of estrogen, phytoestrogens have the advantage of being safer because their chemical structure is different from that of estrogen, which can avoid various side effects caused by the use of estrogen, such as breast cancer and cervical cancer. Studies have shown that phytoestrogens can increase the thickness of the skin layer, inhibit the formation of wrinkles on aging skin, and improve problems such as dry skin and loss of elasticity. Plants such as soybeans and red clover are rich in phytoestrogens, among which isoflavones and lignans are two widely studied phytoestrogens. Although the prior art has disclosed the use of phytoestrogen skin care products and achieved certain results, there are still some problems in practical applications. Especially in summer environments, high temperatures can lead to vigorous skin oil secretion, accelerated skin moisture loss, and the skin's absorption capacity may also decrease. Studies have shown that for every 1°C increase in temperature, the amount of oil produced by the skin increases significantly, and conventional oil-control ingredients are often unable to absorb excess oil and achieve moisturizing properties for a long time. Therefore, traditional skin care products also have shortcomings in terms of durability such as moisturizing and oil resistance.

[0004] To solve these problems, researchers have developed an intelligent-responsive skin care composition. They selected plant extracts with high phytoestrogen content and used hyaluronic acid-polylysine polymer as a carrier for phytoestrogens. By using a thermosensitive polymer to make an emulsion or aqueous solution, this preparation can gelate due to the temperature rise caused by external temperature and form a cosmetic film as a firm thin film. This intelligent-responsive phytoestrogen release mechanism can accurately release phytoestrogens according to temperature changes, thus effectively improving skin dryness, firmness and reducing wrinkles. At the same time, it solves the disadvantages of traditional skin care products in terms of durability during moisturizing and oil resistance, achieving a more precise skin care effect. Summary of the Invention

[0005] The object of the present invention is to provide an intelligent-responsive skin care composition, its preparation method and application to overcome the defects of the above-mentioned existing technologies. This skin care composition has excellent usability, can intelligently and slowly release phytoestrogens according to the skin environmental temperature, and has long-lasting moisturizing, oil resistance, whitening and anti-aging effects even in high-temperature environments such as sweating. It has a more precise skin care effect and can provide appropriate skin care support under different skin conditions.

[0006] The present invention provides an intelligent-responsive skin care composition, including the following raw material components in parts by weight: 1-8 parts of phytoestrogen freeze-dried powder, 3-10 parts of poly(N-isopropylacrylamide), 1-3 parts of chitosan, 0.5-3 parts of a moisturizer, 0.5-3 parts of vitamin C, and 1-10 parts of auxiliary materials.

[0007] The preparation method of the phytoestrogen freeze-dried powder includes the following steps:

[0008] S1. Dissolve 1-5 parts of hyaluronic acid in 30-100 parts of deionized water, then add 0.5-3 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.2-1 part of N-hydroxysuccinimide, and stir evenly to obtain a hyaluronic acid mixture;

[0009] S2. Disperse 2-8 parts of polylysine in 50-100 parts of deionized water to obtain a polylysine dispersion, dropwise add the hyaluronic acid mixture in step S1, stir and react, and dialyze to obtain a hyaluronic acid-polylysine polymer;

[0010] S3. Stir and mix phytoestrogen, lecithin, the hyaluronic acid-polylysine polymer in step S2 with deionized water, and freeze-dry to obtain phytoestrogen freeze-dried powder.

[0011] Preferably, the phytoestrogen is at least one of red clover extract, soybean stem extract, polygonum cuspidatum root extract, and pueraria root extract; more preferably, the phytoestrogen is a combination of red clover extract and polygonum cuspidatum root extract.

[0012] Preferably, the humectant includes at least one of glycerin, sodium hyaluronate, niacinamide, propylene glycol, butylene glycol, and sorbitol.

[0013] Preferably, in step S1, the temperature for uniform stirring is 30 - 50°C, and the stirring time is 1 - 3 h.

[0014] Preferably, in step S2, the temperature for stirring reaction is 40 - 70°C, and the time is 10 - 20 h.

[0015] Preferably, in step S3, the mass ratio of phytoestrogen, lecithin, hyaluronic acid - polylysine polymer, and deionized water is 5 - 10:1 - 3:10 - 20:60 - 80.

[0016] Preferably, the lyophilization conditions in step S3 are: lyophilization at -40°C to -70°C for 1 - 3 h.

[0017] Preferably, calculated by weight, the excipient components include: 0.3 - 1.5 parts of thickener, 0.2 - 0.5 parts of chelating agent, 0.5 - 1.5 parts of emollient, and 0.1 - 3 parts of pH regulator.

[0018] Preferably, the thickener is at least one of carboxymethyl cellulose, hydroxyethyl cellulose, xanthan gum, and carbomer.

[0019] Preferably, the chelating agent is selected from at least one of disodium ethylenediaminetetraacetate, trisodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid, sodium citrate, potassium citrate, and sodium tartrate.

[0020] Preferably, the emollient is at least one of polydimethylsiloxane, polydimethylsiloxanol, hydrogenated polyisobutene, cyclopentasiloxane, cyclohexasiloxane, triglyceride of caprylic / capric acid, and isononyl isononanoate.

[0021] Preferably, the pH regulator is selected from at least one of aminomethyl propanol, arginine, citric acid, and sodium citrate.

[0022] Phytoestrogens exhibit excellent effects in skincare products, but their dispersibility in water-soluble skincare products is poor. Therefore, in this invention, hyaluronic acid-polylysine polymer is innovatively used as a carrier for phytoestrogens. The carboxyl group of hyaluronic acid and the reactive amino group of polylysine form an amide bond through chemical bonding, making this composite carrier amphiphilic, effectively improving the dispersibility of phytoestrogens in water-soluble skincare products and promoting their absorption in the skin. The functional groups rich in hyaluronic acid-polylysine polymer can form hydrogen bonds with water molecules, endowing this polymer with excellent water absorption properties. At the same time, lecithin contains hydrophilic phosphate groups and hydrophobic fatty acid chains. The hydrophilic part of lecithin can interact with functional groups such as carboxyl groups and amino groups in the composite to form a stable and uniform network structure. This network structure not only facilitates the efficient loading of phytoestrogens but also forms a uniform protective film on the skin surface, which can not only effectively repair and strengthen the skin barrier but also reduce water loss, prevent fine lines and wrinkles caused by skin dryness, and thus achieve multiple skincare effects such as moisturizing and anti-aging.

[0023] Among the phytoestrogens used in this invention, red clover extract, soybean stem extract, and kudzu root extract are rich in isoflavone compounds, while polygonum cuspidatum root extract contains abundant resveratrol. Among these plant extracts, a combination of red clover extract and polygonum cuspidatum root extract with a mass ratio of 3:0.5 - 1 is particularly preferred. This combination utilizes the excellent antioxidant, anti-inflammatory, and anti-aging properties of resveratrol and combines with the ability of isoflavones to inhibit the production of reactive oxygen species, effectively reducing the damage of oxidative stress to the skin, thereby delaying skin aging and enhancing the skincare effect.

[0024] Under normal circumstances, the pH value of the human facial skin is usually between 4.5 and 5.5. This weakly acidic environment helps to maintain the health and defense function of the skin, prevent the overgrowth of microorganisms, and maintain the water-oil balance of the skin. When the temperature rises, the human body excretes more sweat to regulate body temperature. The pH value of sweat is usually slightly higher than the natural pH value of the skin. When a large amount of sweat is secreted and covers the skin surface, it may temporarily increase the pH value of the skin, making it closer to neutral or slightly alkaline. This change in pH value caused by temperature changes weakens the skin barrier function, making it more vulnerable to external stimuli and causing the water-oil balance of the skin to be disrupted, making the skin more prone to dryness and tightness.

[0025] To address these changes, the present invention employs a combination of poly(N-isopropylacrylamide) and chitosan. Poly(N-isopropylacrylamide) is a polymer with special temperature-responsive properties. When the external temperature changes, it undergoes an expansion or contraction transition from hydrophilic to hydrophobic, and this volume change can be used to control the release of active ingredients in skin care products. Chitosan contains a large number of amino groups. In acidic conditions, the amino groups of chitosan combine with hydrogen ions to form a swollen state; while in an alkaline environment, the amino groups are deprotonated, and the chitosan chain contracts to form a dense structure. This pH-responsive property of chitosan enables it to swell or contract according to the pH change of the environment, thereby releasing or adsorbing active ingredients. Chitosan also has bactericidal and anti-inflammatory effects, further repairing damaged skin, moisturizing, and delaying skin aging.

[0026] By responding to pH and temperature changes, the skin care composition can achieve continuous release of active ingredients. This mechanism can not only effectively address the weakening of the skin barrier function and the disruption of the water-oil balance caused by temperature changes, but also provide long-term moisturization and protection for the skin, thereby enhancing the skin care effect.

[0027] The intelligent-responsive skin care composition of the present invention further adds vitamin C with antioxidant effects. Vitamin C can effectively neutralize free radicals, reduce the damage of oxidative stress to the skin, thereby delaying skin aging, reducing wrinkles and sagging; in addition, vitamin C can also inhibit the activity of tyrosinase, reduce the production of melanin, improve pigmentation and uneven skin tone problems, making the skin brighter and more uniform. A moisturizer is also added to the composition to further enhance the moisturizing function of the composition.

[0028] The present invention also provides a method for preparing an intelligent-responsive skin care composition, which is characterized by including the following steps: mixing each component uniformly in deionized water under stirring conditions to obtain the intelligent-responsive skin care composition.

[0029] The present invention also relates to the application of the intelligent-responsive skin care composition, which is characterized by being used for preparing facial masks, essence, lotions or creams.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The intelligent-responsive skin care composition of the present invention has multiple effects such as long-term moisturization, anti-oil, whitening, and anti-aging. It can also respond to pH and temperature changes to achieve precise and continuous release of active ingredients, thereby providing more precise skin care effects. This characteristic makes it particularly suitable for skin care needs in high-temperature environments, providing comprehensive and long-lasting skin care. Detailed implementation manners

[0032] To better illustrate the purpose, technical solution and advantages of the present invention, the technical solution of the present invention will be further described below through specific embodiments. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of the claimed rights of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0033] The materials, reagents, etc. used in the following examples and comparative examples are commercially available reagents and materials unless otherwise specified. Unless otherwise specified, the dosage of each component in the following examples is 1 g per weight part or part.

[0034] Experimental materials:

[0035] Red clover extract, Shaanxi Xintianyu Biotechnology Co., Ltd. Soybean stem extract, Nanjing Daosifu Biotechnology Co., Ltd. Polygonum cuspidatum root extract, Shaanxi Xinyanghe Biotechnology Co., Ltd. Pueraria lobata extract, Xi'an Tianyi Biotechnology Co., Ltd.

[0036] I. Preparation of plant-stimulating lyophilized powders A-J.

[0037] 1. The preparation method of phytoestrogen lyophilized powder A is as follows:

[0038] S1. Dissolve 1 part of hyaluronic acid in 30 parts of deionized water, then add 0.5 part of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.3 part of N-hydroxysuccinimide, and stir at 30 °C for 2 h to obtain a hyaluronic acid mixed solution;

[0039] S2. Disperse 5 parts of polylysine in 80 parts of deionized water to obtain a polylysine dispersion, dropwise add the hyaluronic acid mixed solution in step S1, raise the temperature to 60 °C and stir for 20 h, and place it in a dialysis bag to remove unreacted small molecules to obtain a hyaluronic acid-polylysine polymer;

[0040] S3. Mix the soybean stem extract, lecithin, the hyaluronic acid-polylysine polymer in step S2 and deionized water according to a mass ratio of 10:2:15:80, stir and mix at 50 °C for 5 h, and freeze-dry at -50 °C for 2 h to obtain phytoestrogen lyophilized powder A.

[0041] 2. The preparation method of phytoestrogen lyophilized powder B is as follows:

[0042] S1. Dissolve 5 parts of hyaluronic acid in 90 parts of deionized water, then add 3 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1 part of N-hydroxysuccinimide, and stir at 50 °C for 1 h to obtain a hyaluronic acid mixed solution;

[0043] S2. Disperse 8 parts of polylysine in 100 parts of deionized water to obtain a polylysine dispersion. Dropwise add the hyaluronic acid mixture from step S1, heat to 50 °C and stir for reaction for 20 h, and place it in a dialysis bag to remove unreacted small molecules to obtain a hyaluronic acid-polylysine polymer.

[0044] S3. Mix the red clover extract, lecithin, the hyaluronic acid-polylysine polymer from step S2 and deionized water in a mass ratio of 5:2:10:70, stir and mix at 60 °C for 3 h, and freeze-dry at -50 °C for 2 h to prepare the phytoestrogen freeze-dried powder B.

[0045] 3. The preparation method of the phytoestrogen freeze-dried powder C is as follows:

[0046] S1. Dissolve 3 parts of hyaluronic acid in 60 parts of deionized water, then add 2 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1 part of N-hydroxysuccinimide, and stir at 40 °C for 2 h to obtain a hyaluronic acid mixture.

[0047] S2. Disperse 6 parts of polylysine in 60 parts of deionized water to obtain a polylysine dispersion. Dropwise add the hyaluronic acid mixture from step S1, heat to 45 °C and stir for reaction for 15 h, and place it in a dialysis bag to remove unreacted small molecules to obtain a hyaluronic acid-polylysine polymer.

[0048] S3. Mix the polygonum cuspidatum root extract, lecithin, the hyaluronic acid-polylysine polymer from step S2 and deionized water in a mass ratio of 6:1:15:70, stir and mix at 50 °C for 2 h, and freeze-dry at -70 °C for 1.5 h to prepare the phytoestrogen freeze-dried powder C.

[0049] 4. The preparation method of the phytoestrogen freeze-dried powder D is as follows:

[0050] S1. Dissolve 4 parts of hyaluronic acid in 70 parts of deionized water, then add 2.5 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1 part of N-hydroxysuccinimide, and stir at 45 °C for 3 h to obtain a hyaluronic acid mixture.

[0051] S2. Disperse 5.5 parts of polylysine in 70 parts of deionized water to obtain a polylysine dispersion. Dropwise add the hyaluronic acid mixture from step S1, heat to 50 °C and stir for reaction for 18 h, and place it in a dialysis bag to remove unreacted small molecules to obtain a hyaluronic acid-polylysine polymer.

[0052] S3. Mix the pueraria lobata extract, lecithin, the hyaluronic acid-polylysine polymer from step S2 and deionized water in a mass ratio of 7:2:13:75, stir and mix at 45 °C for 1.5 h, and freeze-dry at -60 °C for 2 h to prepare the phytoestrogen freeze-dried powder D.

[0053] 5. The preparation method of phytoestrogen freeze-dried powder E is as follows:

[0054] The difference from freeze-dried powder B is that the red clover extract is replaced by a combination of red clover extract and polygonum cuspidatum root extract with a mass ratio of 3:1, and other conditions are the same as those in the preparation method of freeze-dried powder B.

[0055] 6. The preparation method of phytoestrogen freeze-dried powder F is as follows:

[0056] The difference from freeze-dried powder B is that steps S1 and S2 are omitted, and the hyaluronic acid-polylysine polymer in step S3 is replaced by an equal amount of hyaluronic acid, and other conditions are the same as those in the preparation method of freeze-dried powder B.

[0057] 7. The preparation method of phytoestrogen freeze-dried powder H is as follows:

[0058] The difference from freeze-dried powder B is that steps S1 and S2 are omitted, and the hyaluronic acid-polylysine polymer in step S3 is replaced by an equal amount of polylysine, and other conditions are the same as those in the preparation method of freeze-dried powder B.

[0059] 8. The preparation method of phytoestrogen freeze-dried powder I is as follows:

[0060] The difference from freeze-dried powder B is that the lecithin in step S3 is omitted, and other conditions are the same as those in the preparation method of freeze-dried powder B.

[0061] 9. The preparation method of phytoestrogen freeze-dried powder J is as follows:

[0062] Mix red clover extract, lecithin and deionized water according to a mass ratio of 5:2:70, stir and mix at 60 °C for 3 h, and freeze-dry at -50 °C for 2 h to obtain phytoestrogen freeze-dried powder J.

[0063] II. Preparation of the intelligent-responsive skin care composition.

[0064] Mix the raw material ratios in Table 1 or Table 2 to obtain a premix, and mix each component evenly in deionized water under stirring conditions to obtain an emulsion of the intelligent-responsive skin care composition.

[0065] Among them, the composition of the excipients in the examples and comparative examples is: 1 part of xanthan gum, 0.5 part of disodium ethylenediaminetetraacetate, 0.5 part of polydimethylsiloxane, 0.5 part of cyclohexasiloxane, 0.3 part of arginine, and 0.5 part of sodium citrate.

[0066] Table 1: The weight parts of each component in Examples 1-7 are as follows:

[0067]

[0068] Table 2: The raw material compositions of Comparative Examples 1-7 are as follows:

[0069]

[0070] Performance evaluation:

[0071] 1. Test of experience performance

[0072] To evaluate the mildness and safety of the product, we selected healthy female volunteers aged 40 - 55 years old, randomly divided them into 14 groups with 5 people in each group. Each group of volunteers used the emulsions of the examples and comparative examples respectively for 10 consecutive days, once in the morning and once in the evening every day. The volunteers were required to record their usage feelings, including whether there were discomfort symptoms such as itching, burning, and persistent skin redness.

[0073] The test results showed that no discomfort or allergic reactions occurred during the use of all volunteers, and no symptoms such as itching, burning, or persistent skin redness were reported. This indicates that the emulsion of the present invention has good mildness and safety, will not cause allergic reactions on the human face, and at the same time has an excellent usage experience.

[0074] 2. Determination of moisturizing effect

[0075] Healthy female volunteers aged 40 - 55 years old were selected and randomly divided into 14 groups with 10 people in each group. They used the emulsions provided by the above Examples 1 - 7 and Comparative Examples 1 - 7 respectively. At 0 min, 60 min, 120 min, and 180 min, a skin moisture tester (Corneometer CM825) was used to quantitatively detect the water content of the facial skin. By comparing the water content changes before and after use, the immediate moisturizing effect and long - term water - locking ability of the product were evaluated. Among them, the moisture content and the moisturizing rate after 3 hours of use were the average values of each group of subjects. The moisturizing rate after 3 hours = water content at 180 min / water content at 0 min * 100.

[0076] Table 3 Moisturizing performance test

[0077]

[0078] According to the test data in Table 3, the skin care composition prepared in the embodiments of the present invention exhibits excellent long-lasting moisturizing performance. Experiments show that after three hours of use, the skin moisture content can still be stably maintained above 65%. In contrast, in Comparative Examples 1-4, due to the use of phytoestrogen carriers with insufficient loading capacity, the dispersion of the active ingredients in the emulsion system is poor, directly affecting the persistence of the moisturizing effect. In Comparative Examples 5-7, by omitting the key components of phytoestrogen, thermosensitive polymer (poly(N-isopropylacrylamide)) or biocompatible matrix (chitosan), the integrity of the intelligent-responsive phytoestrogen system is damaged, resulting in a significant decrease in the sustained-release performance of the composition under high-temperature conditions. The lack of this sustained-release ability directly leads to the inability of the active ingredients to be released as needed, and ultimately the long-lasting moisturizing performance of the comparative example compositions decreases by more than 20% compared to the example group, fully verifying the technical advantages of the formula design of the present invention in maintaining the skin hydration state.

[0079] 3. Anti-aging test

[0080] To evaluate the anti-aging efficacy of emulsions with different formulations, a total of 70 healthy female volunteers aged 40-55 who have been engaged in outdoor work for a long time were selected in this study and randomly divided into 14 groups (5 people in each group). The volunteers in each group used the emulsion products prepared in Examples 1-7 and Comparative Examples 1-7 respectively, and applied them once in the morning and once in the evening every day for 3 consecutive months from June 1st to August 31st. After the volunteers continuously used the products for 1 month, 2 months, and 3 months, the VISIA facial image analyzer was used to quantitatively evaluate the improvement of facial wrinkles, and the wrinkle reduction rate was calculated through the following formula:

[0081] Wrinkle reduction rate (%) = (Initial wrinkle depth - Current wrinkle depth) / Initial wrinkle depth × 100%.

[0082] Table 4 Anti-aging performance test

[0083]

[0084] The test results show that by combining poly(N-isopropylacrylamide) and chitosan, the present invention achieves intelligent responses to temperature and pH value. Even in high-temperature environments such as sweating, the composition can still effectively and slowly release active ingredients such as isoflavones, thereby providing more precise skin care effects. During long-term use, the products in the example group showed significant anti-wrinkle effects within 3 months, with a wrinkle reduction rate exceeding 40%, which was significantly better than that of the control group. In addition, compared with Example 2, Examples 5-7 used a combination of red clover extract and polygonum cuspidatum root extract as the source of phytoestrogens, showing more excellent long-term moisturizing performance. This may be attributed to the excellent antioxidant, anti-inflammatory, and anti-aging properties of resveratrol, as well as the ability of isoflavones to inhibit the generation of reactive oxygen species. The synergistic effect of the two effectively delays skin aging and further improves the overall skin care effect.

[0085] Compared with Example 2, the phytoestrogen carriers used in Comparative Examples 1-4 have insufficient loading capacity, resulting in poor dispersion of phytoestrogens in the emulsion; Comparative Examples 5-7 omitted phytoestrogen, poly(N-isopropylacrylamide), or chitosan, respectively. In high-temperature environments such as sweating, Comparative Examples 1-7 cannot sustainably release active components for a long time, which in turn leads to the weakening of the skin barrier function and the disruption of the water-oil balance caused by temperature changes, ultimately weakening the anti-wrinkle effect.

[0086] 4. Whitening Test

[0087] Experimental method: A total of 70 healthy female volunteers aged 40-55 who have been engaged in outdoor work for a long time were randomly divided into 14 groups (5 people in each group). Each group used the emulsions of Examples 1-7 and Comparative Examples 1-7, respectively, once in the morning and once in the evening from July 1st to August 1st for 1 month. The average value of the skin brightness change (△L) before and after use was measured with a color difference meter and calculated. The results are shown in Table 5.

[0088] Table 5 Whitening Test Results

[0089]

[0090] As shown in Table 5, compared with Comparative Examples 1-7, the intelligent response phytoestrogen skin care compositions prepared in Examples 1-7 showed significant advantages in terms of skin brightness change (△L) and had good whitening effects. Among them, the whitening effects of Examples 6-7 were the most prominent. In contrast, the phytoestrogen carriers used in Comparative Examples 1-4 had insufficient loading capacity, resulting in poor dispersion of phytoestrogens in the emulsion. In addition, Comparative Examples 5-7 omitted phytoestrogen, poly(N-isopropylacrylamide), or chitosan, respectively, which further weakened the performance of the composition. In high-temperature environments such as sweating, the compositions of Comparative Examples 1-7 could not achieve long-term sustained release of active components (such as isoflavones, etc.), so they could not provide lasting skin care effects on the skin surface, resulting in a decline in whitening performance.

[0091] The above embodiments are only examples provided to illustrate the present invention and are not limitations on the possible implementation manners of the present invention. Based on the content disclosed in the present invention, those skilled in the relevant art can make various forms of modifications and adjustments. It is impossible and unnecessary to list all possible implementation manners. Any modifications, equivalent substitutions or improvements made within the basic principles and scope of the present invention shall be regarded as falling within the protection scope of the present invention.

Claims

1. A smart responsive skin care composition, characterized in that: The invention comprises the following raw materials in parts by weight: 1-8 parts of phytoestrogen freeze-dried powder, 3-10 parts of poly (N-isopropylacrylamide), 1-3 parts of chitosan, 0.5-3 parts of moisturizing agent, 0.5-3 parts of vitamin C, and 1-10 parts of auxiliary materials; The preparation method of the phytoestrogen freeze-dried powder comprises the following steps: S1. Dissolve 1-5 parts of hyaluronic acid in 30-100 parts of deionized water, then add 0.5-3 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.2-1 parts of N-hydroxysuccinimide, and stir evenly to prepare a hyaluronic acid mixed solution; S2, dispersing 2-8 parts of polylysine in 50-100 parts of deionized water to obtain a polylysine dispersion, adding the hyaluronic acid mixture of step S1 dropwise, stirring to react, and dialyzing to obtain a hyaluronic acid-polylysine polymer; S3, stirring and mixing the phytoestrogen, lecithin, the hyaluronic acid-polylysine polymer of step S2 and deionized water, and freeze-drying to obtain a phytoestrogen freeze-dried powder.

2. The smart response skin care composition according to claim 1, characterized in that: The phytoestrogen is at least one of red clover extract, soybean stem extract, knotweed root extract and kudzu root extract.

3. The smart response skin care composition according to claim 1 or 2, characterized in that: The phytoestrogen is a combination of red clover extract and knotweed root extract in a mass ratio of 3:0.5-1.

4. The smart response skin care composition according to claim 1, characterized in that: The moisturizing agent includes at least one of glycerin, sodium hyaluronate, niacinamide, propylene glycol, butylene glycol, and sorbitol.

5. The smart response skin care composition according to claim 1, characterized in that: The stirring temperature in step S1 is 30-50° C. and the stirring time is 1-3 h; the stirring reaction temperature in step S2 is 40-70° C. and the time is 10-20 h.

6. The smart response skin care composition according to claim 1, characterized in that: In the step S3, the mass ratio of phytoestrogen, lecithin, hyaluronic acid-polylysine polymer and deionized water is 5-10:1-3:10-20:60-80; the freeze-drying condition of the step S3 is freeze-drying at -40°C to -70°C for 1-3h.

7. The smart response skin care composition according to claim 1, characterized in that: The auxiliary materials include, by weight, 0.3-1.5 parts of thickener, 0.2-0.5 parts of chelating agent, 0.5-1.5 parts of emollient, and 0.1-3 parts of pH regulator.

8. The smart response skin care composition according to claim 7, characterized in that: The thickener is at least one of carboxymethyl cellulose, hydroxyethyl cellulose, xanthan gum and carbomer; The chelating agent is selected from at least one of disodium ethylenediaminetetraacetate, trisodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid, sodium citrate, potassium citrate, and sodium tartrate; The emollient is at least one of dimethicone, dimethiconol, hydrogenated polyisobutene, cyclopentasiloxane, cyclohexasiloxane, caprylic / capric triglyceride and isononyl isononanoate; The pH regulator is selected from at least one of aminomethyl propanol, arginine, citric acid and sodium citrate.

9. A method for preparing the smart response skin care composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components are uniformly mixed in deionized water under stirring conditions to prepare an intelligent responsive skin care composition.

10. An application of the smart response skin care composition according to any one of claims 1 to 8, characterized in that: Use to prepare facial masks, serums, lotions or creams.

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