EGCG (epigallocatechin gallate)-containing tightening and whitening composition as well as preparation method and application thereof

Abstract

The invention discloses a tightening and whitening composition containing EGCG (epigallocatechin gallate) as well as a preparation method and application of the tightening and whitening composition, and relates to the technical field of cosmetics. The invention provides a tightening and whitening composition containing EGCG (epigallocatechin gallate). The tightening and whitening composition is prepared from the following components in parts by weight: 0.1 to 2 parts of an epigallocatechin gallate nano composition, 0.05 to 0.5 part of a nucleic acid tetrahedron and 0.5 to 5 parts of glassine. When the EGCG nano composition, the nucleic acid tetrahedron and the glassine are cooperatively used, the stability of a formula can be improved, meanwhile, the EGCG can be accurately released to an epidermal layer due to the enzyme-responsive degradation characteristic (such as matrix metalloproteinase MMP-2 triggered depolymerization) of the nucleic acid tetrahedron, and the glassine is released after deeply penetrating into a corium layer along with a nucleic acid tetrahedron carrier, so that the EGCG can be accurately released to the epidermal layer. The synergistic effects of the three components on whitening and tightening are better exerted.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, in particular to an EGCG-containing firming and whitening composition, and a preparation method and application thereof. Background Art

[0002] Skin whitening and firming are core cosmetics product appeals to consumers, but current products on the market are generally single-acting whitening or single-acting firming products, facing the problem of insufficient synergy. Current technologies often use single active ingredients such as arbutin and retinol to inhibit melanin or collagen synthesis, respectively, lacking a mechanism for simultaneously regulating epidermal whitening and dermal firming. Furthermore, the active ingredients in traditional formulas are prone to low transdermal absorption rates, such as those of large-molecule collagen, and poor photothermal stability, such as those of vitamin C and its derivatives. This can compromise their actual efficacy during application, preventing them from being effectively utilized and making it difficult to meet consumers' demand for effective and safe skin care.

[0003] The country advocates and encourages the research and development of green technologies such as synthetic biology, and promotes the development of skin microecology research and nanocarrier technology. Consumers are in urgent need of a new type of composite system product that can achieve whitening and firming, with high bioavailability and low irritation.

[0004] In view of this, this application is filed. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a firming and whitening composition containing EGCG and its preparation method and application.

[0006] To achieve the above objectives, in the first aspect of this application, the technical solution adopted by the present invention is: a firming and whitening composition containing EGCG, comprising the following components in parts by weight: 0.1-2 parts of epigallocatechin gallate nanocomposition, 0.05-0.5 parts of nucleic acid tetrahedron, and 0.5-5 parts of bosine.

[0007] Epigallocatechin gallate (EGCG), with its extremely small molecular weight of less than 500 Daltons, can effectively penetrate the dermis. With a pH range of 5-6, it is less likely to cause irritation when applied to the skin, making it a potential cosmetic ingredient. By combining it with other ingredients, it can effectively promote synergistic effects after absorption. Tetrahedron nucleic acid (tFNA), developed based on DNA origami technology, is a nucleic acid molecule with a tetrahedral framework structure formed by denaturation and renaturation of four single-stranded DNAs, based on complementary base pairing between the strands. It has a specific sequence, specific scale, specific spatial conformation, and specific biological properties. Furthermore, the tetrahedral structure of the nucleic acid tetrahedron, composed of four triangles, possesses extremely high mechanical strength and stability. This structural advantage gives tFNA powerful carrier properties. tFNA is also highly hydrophilic, has good film-forming properties in solution, and has strong absorption properties for ultraviolet rays (230-320nm), showing great potential for application in the cosmetics industry. Bosyl (hydroxypropyl tetrahydropyrantriol) is a synthetic xylose derivative (molecular formula C8H 16 O5), can improve the skin's water retention capacity by increasing the hyaluronic acid content, strengthen the dermal-epidermal connection, stimulate the production of type IV and type VII collagen, and enhance skin elasticity and firmness.

[0008] The synergistic use of the epigallocatechin gallate nanocomposite, nucleic acid tetrahedron and phosphatidylcholine in the present invention can improve the stability of the formula. At the same time, the enzyme-responsive degradation characteristics of the nucleic acid tetrahedron (such as matrix metalloproteinase MMP-2 triggered depolymerization) can accurately release EGCG to the epidermis, while phosphatidylcholine is released after deep penetration into the dermis along with the nucleic acid tetrahedron carrier, thereby better exerting the synergistic effects of the above three components on whitening and firming.

[0009] The epigallocatechin gallate nanocomposition of the present invention can be a commercially available product or homemade. The preparation method has a reference application number: 202410920897.3. The invention name is: An EGCG nanocomposition with strong antioxidant and anti-photoaging effects, and its preparation method and application.

[0010] Specifically, it is achieved through the following technical solution: the EGCG nanocomposite is formed by two-step functional phospholipid self-assembly to encapsulate the active ingredient EGCG, including the first step of nanocomposite precursor preparation process and the second step of dual phospholipid nanocomposite preparation process.

[0011] A method for preparing an EGCG nanocomposition with strong antioxidant and anti-photoaging effects comprises the following steps:

[0012] (1) Preparation of a nanocomposite precursor: adding phospholipids and EGCG to an organic solvent and stirring uniformly to obtain an organic phase; adding a polyol to water and stirring uniformly to obtain an aqueous phase; dropping the organic phase into the aqueous phase at a uniform rate, and continuing to stir after the addition is complete to obtain a mixed solution; removing the organic solvent from the obtained mixed solution; and drying the mixed solution to obtain a nanocomposite precursor; the phospholipid content in the mixed solution is 1% to 10% by mass;

[0013] (2) Preparation of dual phospholipid nanocomposites:

[0014] The phospholipid, rigid membrane material stabilizer, and flexible membrane material stabilizer are added to a polyol and stirred to obtain an alcohol phase; the nanocomposite precursor is added to water and stirred to obtain an aqueous phase; the aqueous phase is uniformly added dropwise to the alcohol phase, and after the addition is complete, stirring is continued to obtain a mixed solution; the mixed solution is subjected to nano-processing to obtain an EGCG nanocomposite, wherein the mass percentage of EGCG in the EGCG nanocomposite is 0.6%-6.0%;

[0015] In terms of mass percentage, the phospholipid content in the mixed solution is 0.1%-1.0%, the rigid membrane material stabilizer content is 0.1%-0.3%, and the flexible membrane material stabilizer content is 0.5%-2.0%;

[0016] The molecular structure of the rigid film material stabilizer contains polycyclic structural units or benzene ring structural units; the molecular structure of the flexible film material stabilizer is a straight chain type or a straight chain compound.

[0017] Preferably, the EGCG-containing firming and whitening composition comprises the following components in parts by weight: 0.5-1 parts of epigallocatechin gallate nanocomposition, 0.1-0.3 parts of nucleic acid tetrahedron, and 1-2 parts of bosine.

[0018] The inventors found in actual experimental processes that when the weight proportions of the components in the EGCG-containing firming and whitening composition are further selected to be within the above range, the overall performance of the obtained product is better.

[0019] Preferably, based on the total weight of the firming and whitening composition containing EGCG, the weight percentage of the epigallocatechin gallate nanocomposition is 30-40%.

[0020] Preferably, based on the total weight of the firming and whitening composition containing EGCG, the weight percentage of the nucleic acid tetrahedron is 5-10%.

[0021] During actual experiments, the inventors found that further limiting the weight percentage range of epigallocatechin gallate nanocompositions or nucleic acid tetrahedrons in the total weight of the EGCG-containing firming and whitening composition can achieve better results, and the resulting product has better whitening and firming effects.

[0022] In the second aspect of the present application, the present application provides the use of the EGCG-containing firming and whitening composition in the preparation of skin products.

[0023] In the third aspect of the present application, the present application provides a skin product, comprising the EGCG-containing firming and whitening composition.

[0024] Preferably, the skin products include cosmetics and skin care products; the skin care products include any one of lotion, emulsion, cream, mask, essence, essence oil, spray, and sunscreen; the cosmetics include any one of liquid foundation and lipstick.

[0025] In a fourth aspect of the present application, the present application provides an essence comprising the following components in percentage by mass: 0.5-3% of the EGCG-containing firming and whitening composition, 2-40% of a cosmetic base, and the balance being water.

[0026] Preferably, the cosmetic base includes at least one of a thickener, a moisturizer, a preservative, and a pH adjuster.

[0027] Preferably, the thickener includes at least one of xanthan gum, carbomer, hydroxyethyl cellulose, etc.; the moisturizer includes at least one of glycerin, hyaluronic acid, urea, polyols (propylene glycol, butylene glycol, 1,2-pentanediol, etc.); the preservative includes at least one of phenoxyethanol, potassium sorbate, sodium benzoate, etc.; the pH adjuster includes at least one of citric acid, sodium citrate, sodium hydroxide, triethanolamine, disodium EDTA, etc.

[0028] In a specific embodiment, the present invention provides an essence comprising the following components in mass percentage: 0.1-0.3% xanthan gum, 3-5% glycerol, 0.5-3% of the EGCG-containing firming and whitening composition, 2-3% 1,2-pentanediol, 0.05-0.1% disodium EDTA, 0.1-0.01% phenoxyethanol, and 0.1-0.5% citric acid / sodium citrate buffer.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: when the three components of the present invention, namely, the epigallocatechin gallate nanocomposite, nucleic acid tetrahedron and phosphatidylcholine, are used synergistically, the stability of the formula can be improved; at the same time, the enzyme-responsive degradation characteristics of the nucleic acid tetrahedron (such as matrix metalloproteinase MMP-2 triggered depolymerization) can accurately release EGCG to the epidermis, while phosphatidylcholine is released after deep penetration into the dermis along with the nucleic acid tetrahedron carrier, thereby better exerting the synergistic effects of the above three components on whitening and firming. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Figure 2 shows the study of transdermal penetration of substances into the skin. DETAILED DESCRIPTION

[0031] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below with reference to the accompanying drawings and specific examples. Its purpose is to understand the content of the present invention in detail, rather than to limit the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise specified, the experimental reagents and instruments designed for the implementation and comparative examples of the present invention are all commonly used ordinary reagents and instruments, which can be obtained from commercial channels. In the implementation and comparative examples, the experimental methods used are all conventional methods unless otherwise specified; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch of raw materials.

[0032] The raw materials used in the examples of this application are now further described, but are not limited to the following raw materials:

[0033] EGCG nanocomposition-1: Guangzhou Xiyuan Biological Co., Ltd., the active ingredient EGCG accounts for 3% of the EGCG nanocomposition.

[0034] EGCG nanocomposite-2 was prepared in-house. The preparation method is as follows. The EGCG used (purity 98%) can be purchased directly from Shanghai Aladdin Biotechnology Co., Ltd.:

[0035] (1) Preparation of nanocomposite precursor: 5.0% by mass of soybean lecithin and 15% by mass of EGCG were added to 30% by mass of anhydrous ethanol, and stirred at 60°C (speed of 300 rpm) for 30 minutes until the above raw materials were fully dissolved to obtain an organic phase. 5% by mass of maltitol was added to 45% by mass of deionized water, and stirred at 60°C (speed of 300 rpm) for 30 minutes until the above raw materials were fully dissolved to obtain an aqueous phase. Under the condition of maintaining the above organic phase, the dripping speed of 3 ml / min was uniformly added to the aqueous phase. After the dripping was completed, the mixture was continued at 60°C.

[0036] The mixture was stirred (at 300 rpm) for 15 minutes to obtain a mixed solution. The ethanol was removed by rotary evaporation at 150 rpm, 40°C, and 2 hours. The mixture was then freeze-dried for 48 hours to obtain a nanocomposite precursor. The nanocomposite precursor had a mass percentage of phospholipids: EGCG: maltitol = 20%: 60%: 20%.

[0037] (2) Preparation of EGCG nanocomposite: 0.3% by mass of hydrogenated lecithin, 0.15% by mass of cholesterol, and 1.5% by mass of caprylic / capric triglyceride were added to a mixed solution of 25% by mass of glycerol and 10% by mass of 1,2-hexanediol. The mixture was stirred at 30°C (300 rpm) for 30 min until the above raw materials were fully dissolved to obtain an alcohol phase. 5% by mass of the nanocomposite precursor was added to 58.05% by mass of deionized water. The mixture was stirred at 30°C (300 rpm) for 30 min until the nanocomposite precursor was uniformly dispersed to obtain an aqueous phase. While maintaining the temperature at 30°C, the aqueous phase was uniformly added dropwise to the alcohol phase at a rate of 3 ml / min. After the addition was completed, the mixture was stirred at 30°C (300 rpm) for 15 min to obtain a mixed solution. The mixed solution was dispersed by high-speed shearing (10000 rpm) for 20 min; and then subjected to high-pressure microfluidization homogenization with a homogenization pressure of 80 MPa and four homogenization times to obtain an EGCG nanocomposite.

[0038] The active ingredient EGCG accounts for 3% of the EGCG nanocomposition.

[0039] Nucleic Acid Tetrahedron: Jiangsu Chuangjian Medical Technology Co., Ltd.;

[0040] Bose-like peptide-2 (BPS): Guangzhou Xiyuan Biological Co., Ltd., powdered;

[0041] Tea polyphenols: purchased from Shaanxi Baichuan Biotechnology Co., Ltd.

[0042] PDRN: purchased from Baihong Biotechnology Group Co., Ltd.;

[0043] RNA: purchased from Jiangsu Sesofei Biotechnology Co., Ltd.

[0044] Trehalose: purchased from Croda Chemicals (Shanghai) Co., Ltd.

[0045] The remaining cosmetic formula raw materials are conventional commercially available products.

[0046] Examples and Comparative Examples

[0047] The present invention provides a firming and whitening composition containing EGCG. The components and weight portions of the firming and whitening composition containing EGCG are shown in Table 1-2. The preparation method of the firming and whitening composition containing EGCG comprises the following steps: uniformly mixing the components to obtain the firming and whitening composition containing EGCG.

[0048] Table 1

[0049]

[0050] Table 2

[0051]

[0052]

[0053] Performance Test-1 Substance Transdermal Permeation Study

[0054] 1. Test purpose and principle

[0055] 1.1 Purpose of the Test

[0056] This experiment aimed to evaluate the transdermal permeation efficacy of the compositions of Example 1 and Comparative Examples 1-3 using a full skin organ-on-a-chip model developed by Shenzhen Yixin Life Sciences. By simulating a real skin environment, the differences in permeation efficacy of the four substances were accurately measured, yielding precise permeation data.

[0057] 1.2 Test Principle

[0058] This experiment, based on the transdermal absorption of substances through the skin, employed a skin organ-on-a-chip model to further investigate their transdermal absorption. Example 1 and Comparative Examples 1-3 were conjugated with the fluorescent substance FITC and exposed to the skin model for 24 hours, whereupon the substance's transdermal absorption was observed. Laser confocal microscopy was used to visualize and analyze the fluorescent substance, allowing for precise determination of the transdermal efficacy of each substance.

[0059] 2. Test materials and instruments

[0060] 2.1 Test reagents and materials

[0061] Skin Organ Chips

[0062] Reagents: DPBS, the composition prepared in Example 1, the compositions prepared in Comparative Examples 1-3, FITC, 4% paraformaldehyde, sucrose, and OCT.

[0063] 2.2 Experimental instruments

[0064] NIKON AX laser confocal microscope

[0065] 3. Test methods

[0066] 3.1 Main operation steps

[0067] First, the composition prepared in Example 1 and the composition prepared in Comparative Examples 1-3 were applied to 12 full skin models, with three parallel experiments set up in each group. 400 μL of test solution was added to the upper surface of each model, and 800 μL of culture medium solution was added to the lower chamber. Subsequently, the skin model was placed in an incubator in the dark for 24 hours, the test substance and culture medium in the model were discarded, and the surface of the model was washed twice with DPBS to remove excess substances. The model was placed in a 4% paraformaldehyde fixative for 24 hours, and dehydrated in 10%, 20%, and 30% sucrose solutions, respectively, until the model sank to the bottom in a 30% sucrose solution, indicating that the dehydration was complete. It was embedded in OCT, frozen sectioned, and sliced at a thickness of 10 μm. The fluorescence in the slices was observed to evaluate the transdermal retention effect of the four substances in the whole skin.

[0068] 3.2 Data processing

[0069] Excel, GraphPad Prism 9.0, Origin, and Image J software were used for statistical processing of data.

[0070] 4. Experimental results, such as Figure 1 shown.

[0071] Depend on Figure 1 It can be seen that Comparative Example 3 containing EGCG nanocomposition and nucleic acid tetrahedron and Example 1 containing all three exhibited unique transmembrane delivery advantages, and the fluorescence signal intensity in the epidermis was significantly improved compared with the other two groups, indicating that the combination of EGCG nanocomposition and nucleic acid tetrahedron can significantly promote the specific uptake of active ingredients by epidermal keratinocytes. The relative fluorescence intensity of the dermis of Example 1 and Comparative Example 3 was significantly improved compared with that of Comparative Example 1 and Comparative Example 2, and a gradient sustained release feature was presented in the epidermal-dermal junction area. The combination of the three helps to improve the overall retention in the skin layer, thereby improving the efficacy.

[0072] Performance Test-2 Zebrafish Firming Efficacy Test Method

[0073] Testing process:

[0074] Method source: "T / ZHCA 015-2022 Evaluation of Cosmetic Firming Efficacy - Zebrafish Elastin Gene Relative Expression Method."

[0075] System and samples Experimental system: wild-type AB strain zebrafish.

[0076] Zebrafish age: 4 days post fertilization (4 dpf).

[0077] The number of experimental samples in each group was 30 (three biological replicates, N=3).

[0078] Adult fish rearing and breeding methods: follow the company's laboratory standard rearing and breeding methods, in line with the requirements of the international AAALAC certification (certification number: 001458).

[0079] Principle and Method: Elastin is the primary component of elastic fibers in skin tissue, providing structural support and protecting the skin from aging and sagging. Elastin is composed of two alternating short peptides. Eln1 and eln2 encode different peptides of elastin. These two genes jointly regulate elastin expression, contributing to skin firmness and elasticity. Zebrafish possess elastin genes (eln1 and eln2) similar to those in humans. Therefore, measuring the relative expression of the eln1 and / or eln2 genes can indicate whether a sample has a firming effect.

[0080] Experimental steps: 1. Randomly select zebrafish in a 6-well plate, with 30 fish per well. 2. Dissolve the composition samples of Examples 1-6 and Comparative Examples 1-11 in water at a concentration of 0.5%, and set up a normal control group (5% bosine) with a capacity of 3 mL per well. Perform three biological replicates. 3. Incubate in the dark at 28°C for 24 hours. 4. Extract total RNA from zebrafish in each experimental group, synthesize cDNA, and use q-PCR to detect gene expression of β-actin and the target gene. 5. Use β-actin as an internal reference for gene expression to calculate the relative RNA expression of the target gene.

[0081] Relative RNA expression = 2 ΔΔC(t)

[0082] Sample group ΔC(t)=C(t) 目的基因 -C(t) β -actin

[0083] Applicability and limitations: Applicable to the firming efficacy testing of cosmetics and their raw materials. The sample must be soluble in water or prepared into a suspension that can be evenly dispersed in water.

[0084] Judgment basis: Statistical analysis p < 0.05, it is judged to be significantly different.

[0085] Test results: as shown in Table 3.

[0086] Table 3

[0087]

[0088]

[0089] As can be seen from the above table, the EGCG-containing firming and whitening composition prepared in the embodiment of the present invention, when the three components of epigallocatechin gallate nanocomposite, nucleic acid tetrahedron and bosine are used in coordination, has a good firming effect.

[0090] As can be seen from Example 1 and Comparative Examples 1-5, when one of the components is not added, or when it is not added and the other components are used to make up the difference, the effects of the present invention cannot be achieved; as can be seen from Example 1 and Comparative Examples 6-8, when other similar components are used instead, the corresponding effects of the present invention cannot be achieved. As can be seen from Example 1 and Comparative Example 9, when the weight ratios of the components in the composition are not within the range of this application, a good synergistic effect cannot be achieved.

[0091] Application Examples

[0092] The application examples, comparative application examples and blank application examples of the present invention provide an essence, the components (mass percentage) of the essence are shown in Table 4; wherein, the EGCG-containing firming and whitening compositions used in Application Examples 1-6 are respectively the EGCG-containing firming and whitening compositions prepared in Examples 1-6, for example, the EGCG-containing firming and whitening composition used in Application Example 1 is the EGCG-containing firming and whitening composition in Example 1, the EGCG-containing firming and whitening composition used in Application Example 2 is the EGCG-containing firming and whitening composition in Example 2, and so on; the EGCG-containing firming and whitening compositions used in Comparative Application Examples 1-11 are respectively the EGCG-containing firming and whitening compositions prepared in Comparative Examples 1-11; the EGCG-containing firming and whitening composition used in Application Example 7 is the EGCG-containing firming and whitening composition prepared in Example 1;

[0093] Table 4

[0094]

[0095]

[0096] The preparation method of the essence in Application Example 1 includes the following steps. The preparation methods of the other application examples are similar to those in Application Example 1, except that no relevant components are added:

[0097] 1. Preparation

[0098] Raw material preparation: Weigh all raw materials according to the recipe to ensure their quality. Heat deionized water to 70-80℃ and set aside.

[0099] 2. Preparation of aqueous matrix

[0100] Dissolve the polymer: Pour heated deionized water into a mixing tank and start the agitator at 350 rpm. Stir for 10 minutes until completely dissolved. Next, add the xanthan gum and continue stirring for 15 minutes to ensure even dispersion and increase the viscosity of the solution. Add glycerin and stir for 10 minutes until the solution is homogeneous and transparent.

[0101] 3. Adding active ingredients

[0102] Dissolve the EGCG-containing firming and whitening composition in an appropriate amount of deionized water and stir evenly. Slowly add the dissolved solution to the mixing tank and stir for 10 minutes to ensure it is evenly dispersed.

[0103] 4. Addition of auxiliary system

[0104] Add 1,2-pentanediol, disodium EDTA, and phenoxyethanol and stir for 8 minutes.

[0105] Adjust pH: Adjust pH to 6.0 with citric acid / sodium citrate buffer and stir for 5 minutes to ensure homogeneity.

[0106] 5. Homogenization and Filtration

[0107] Homogenization: The solution was homogenized at a pressure of 70 bar for 5 minutes to ensure uniform dispersion of the components.

[0108] Filtration: Filter through 0.3μm filter equipment to remove impurities.

[0109] 6. Cooling and filling

[0110] Cooling: Allow the solution to cool naturally to room temperature, or use cooling equipment to accelerate cooling.

[0111] Filling and sealing: Fill into packaging containers, ensuring the correct filling volume, seal tightly, and apply labels.

[0112] 7. Quality Inspection

[0113] Appearance inspection: Check whether the essence is uniform and transparent, without precipitation or stratification.

[0114] Physical and chemical testing: testing indicators such as pH value, viscosity, and component content.

[0115] Microbiological testing: ensure that the product is sterile and meets hygiene standards.

[0116] Performance Test-3 Human Whitening Efficacy-Skin MI Value

[0117] Testing process:

[0118] 1. Test product: the essence prepared in the application examples and comparative application examples;

[0119] 2. Negative control: blank control of the blackened area, the blank control does not receive any treatment.

[0120] 3. Positive control: 7% ascorbic acid (vitamin C) product, prepared according to the formula in Appendix I of the "Technical Specifications for Safety of Cosmetics" (2015 edition) Announcement No. 17 of 2021 of the State Food and Drug Administration.

[0121] 4. Subjects: Valid subjects who completed the test were divided into groups of 5, with a total of 21 groups, including 50 males and 55 females, aged 19 to 59 years old, who met the voluntary inclusion and exclusion criteria.

[0122] 5. Instruments and Equipment

[0123] 5.1 Solar simulator: All performance indicators meet the requirements of the measurement specifications.

[0124] 5.2 Skin melanin detector: an instrument that detects skin MI value based on the principle of spectral absorption.

[0125] 6. Test method: Test in accordance with the specific requirements of the Technical Specifications for Safety of Cosmetics (2015 edition).

[0126] The non-exposed area of the subject's thigh was selected as the test site. The area of each blackened test area should be no less than 0.5 cm 2 , and should be located within each smear area. Determine the MED of the test site of the subject. Use a solar simulator to irradiate the same irradiation point at a dose of 0.75 times the MED once a day for 4 consecutive days. The 4 days after the end of irradiation are the skin blackening period and no treatment is performed. On the 5th day after the end of irradiation, the skin of each test area is visually evaluated and instrumentally tested for skin color, and test areas with poor consistency are eliminated. Starting from the 5th day, the corresponding test substance is applied to each blackening test area according to the random table. The test substance is applied continuously for at least 4 weeks. The skin color should be visually evaluated and instrumentally tested 1 week and 4 weeks after application, and recorded.

[0127] 7. Calculation method: 1. Statistical analysis was performed using the independent sample t-test (or rank sum test). Compared with the negative control, *p<0.05. 2. Difference = skin parameters after product use - skin parameters before product use.

[0128] Test results: as shown in Table 5.

[0129] Table 5 Difference in skin MI before and after product use (mean)

[0130]

[0131]

[0132] As can be seen from the above table, after the EGCG-containing firming and whitening composition prepared in the embodiment of the present invention is prepared into an essence, the three components of epigallocatechin gallate nanocomposite, nucleic acid tetrahedron and bosine have a good whitening effect when used in conjunction.

[0133] As can be seen from the comparison between Application Example 1 and Comparative Application Examples 1-5, when one of the components is not added, or when it is not added and the other components are used to make up for it, the effect of the present invention cannot be achieved; as can be seen from the comparison between Application Example 1 and Comparative Application Examples 6-8, when other similar components are used as substitutes, the corresponding effect of the present invention cannot be achieved. As can be seen from the comparison between Application Example 1 and Comparative Application Example 9, when the weight proportions of the components in the composition are not within the range of this application, a good synergistic effect cannot be achieved.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A firming and whitening composition containing EGCG, characterized in that: The invention comprises the following components in parts by weight: 0.1-2 parts of epigallocatechin gallate nanocomposite, 0.05-0.5 parts of nucleic acid tetrahedron and 0.5-5 parts of bosine.

2. The EGCG-containing firming and whitening composition according to claim 1, wherein The invention comprises the following components in parts by weight: 0.5-1 part of epigallocatechin gallate nanocomposite, 0.1-0.3 part of nucleic acid tetrahedron and 1-2 parts of bosine.

3. The EGCG-containing firming and whitening composition according to claim 1, wherein Based on the total weight of the firming and whitening composition containing EGCG, the weight percentage of the epigallocatechin gallate nanocomposition is 30-40%.

4. The EGCG-containing firming and whitening composition according to claim 1, wherein Based on the total weight of the firming and whitening composition containing EGCG, the weight percentage of the nucleic acid tetrahedron is 5-10%.

5. Use of the EGCG-containing firming and whitening composition according to any one of claims 1 to 4 in the preparation of skin products.

6. A skin care product, characterized in that: The invention comprises the EGCG-containing firming and whitening composition according to any one of claims 1 to 4.

7. The skin care product according to claim 6, wherein: The skin products include cosmetics and skin care products; the skin care products include any one of lotion, emulsion, cream, mask, essence, essence oil, spray, and sunscreen; the cosmetics include any one of liquid foundation and lipstick.

8. The skin care product according to claim 7, wherein: The skin product is an essence.

9. An essence, characterized in that: The essence comprises the following components in percentage by mass: 0.5-3% of the firming and whitening composition containing EGCG according to any one of claims 1 to 4, 2-40% of a cosmetic base, and the balance being water.

Images