Multi-effect face brightening and tightening essence and preparation method thereof

Abstract

The invention relates to the technical field of cosmetics, in particular to multi-effect face brightening and tightening essence and a preparation method thereof, and the formula of the essence comprises alpha-arbutin, bifidus yeast fermentation liquor, palmitoyl pentapeptide-4, glycerol and a microemulsion system. The microemulsion system is composed of accurately quantitative polysorbate, ethanol, propanol, squalane, caprylic / capric triglyceride and a water phase. After low-temperature premixing, ultrasonic-assisted dispersion and high-energy homogenization treatment, the micro-emulsion particle size of the product is controlled to be less than 100nm. Human body tests and skin safety verification show that the product has significantly improved skin color improvement, skin tightening and moisturizing effects, and has significantly better long-term stability and low irritation than the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of skin care products, and more particularly to a multi-effect brightening and firming facial essence and a preparation method thereof. Background Art

[0002] Currently, most of the brightening and firming facial essence products on the market use α-arbutin, peptide ingredients, and traditional emulsions or crude microemulsion technology, but they have the following shortcomings:

[0003] (1) Insufficient improvement in skin color: Due to the low stability and skin delivery efficiency of α-arbutin in traditional systems, the actual brightening effect is limited.

[0004] (2) Poor skin firming effect: Single peptide ingredients cannot fully activate skin collagen

[0005] Production of protein and elastin.

[0006] (3) Poor product stability: Traditional emulsion or microemulsion systems are prone to oil-water separation and degradation of active ingredients, resulting in degradation of product performance.

[0007] (4) Safety risks: The concentration of active ingredients in some products is too high or the ratio is unreasonable, which may cause local irritation or allergies.

[0008] Therefore, there is an urgent need to develop a multi-effect facial essence product that can significantly improve skin tone, tighten skin, enhance moisturizing effect, and at the same time has good stability and low irritation. Summary of the Invention

[0009] In order to overcome the defects of the prior art, the present invention provides the following technical solutions:

[0010] A multi-effect brightening and firming facial essence comprises the following components in percentage by mass: 3.0-5.0% of α-arbutin, 8.0-9.0% of bifid yeast fermentation broth, 3.0-4.0% of palmitoyl pentapeptide-4, 4.0-5.0% of glycerol, and the remainder a microemulsion system; the microemulsion system consists of a surfactant, a co-surfactant, an oil phase, and an aqueous phase.

[0011] Preferably, the composition comprises the following components in percentage by mass: 4.0% of α-arbutin, 8.0% of bifid yeast fermentation broth, 3.0% of palmitoyl pentapeptide-4, 5.0% of glycerol and the balance of microemulsion system.

[0012] Preferably, the surfactant in the microemulsion system is polysorbate 80, and its content is 1.0-2.0%.

[0013] Preferably, the co-surfactant comprises ethanol and propanol, and the total content thereof is 0.7-1.0%.

[0014] Preferably, the oil phase is selected from squalane and caprylic / capric triglyceride, each of which has a content of 2.5%, and the total oil phase content is 5.0%.

[0015] Preferably, the aqueous phase consists of distilled water, EDTA, hydroxyethyl cellulose and a pH regulator.

[0016] A method for preparing a multi-effect brightening and firming facial essence comprises the following steps:

[0017] (a) premixing α-arbutin, bifid yeast fermentation broth, palmitoyl pentapeptide-4, and glycerol separately at a temperature not exceeding 30° C.;

[0018] (b) preparing an oil phase and an aqueous phase separately, wherein polysorbate 80, ethanol, propanol, EDTA, hydroxyethyl cellulose, and a pH adjuster are added to the aqueous phase, and squalane and caprylic / capric triglyceride are mixed into the oil phase;

[0019] (c) adding the oil phase dropwise to the aqueous phase to form a preliminary emulsion under low temperature conditions, continuous stirring and with the assistance of ultrasound;

[0020] (d) treating the preliminary emulsion to a microemulsion particle size of less than 100 nm using a high-energy homogenization technique (including ultrasonic emulsification combined with high-speed shearing);

[0021] (e) adding the active ingredients premixed in step (a) to the microemulsion system obtained in step (d), stirring at a low speed until uniformly mixed, and then filling into a light-proof container.

[0022] Preferably, precise temperature control and timing operation are performed during the emulsion homogenization process to ensure that the obtained microemulsion particle size distribution is uniform and the system is stable.

[0023] The present invention has the following beneficial effects:

[0024] (1) Significantly brightens skin tone: After 4 weeks of continuous use, the skin tone L* value increased from 65.0 to 75.2, an improvement rate of 15.7%.

[0025] (2) Enhance skin firmness: The skin firmness recovery index increased from 1.25 to 1.45, with an improvement rate of 16.0%.

[0026] (3) Improve skin moisturizing: Skin moisture content increased from 35.0% to 42.0%, an increase of 20.0%.

[0027] (4) Excellent stability: In the 45°C accelerated aging test, the degradation rate of α-arbutin does not exceed 5%, and the product has no obvious stratification during long-term storage.

[0028] (5) Good safety and tolerance: In the skin patch and local tolerance tests, the irritation score dropped from 0.2 to 0.1, with no significant allergic or irritation reactions. DETAILED DESCRIPTION

[0029] The technical solutions of the present invention are further described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of 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. The methods or operations used in the embodiments, unless otherwise specified, are conventional methods or routine operations in the art.

[0030] This application provides general and / or specific descriptions of the materials and experimental methods used in the experiments. In the following examples, unless otherwise specified, % represents wt%, i.e., percentage by weight. All reagents or instruments used without manufacturer indication are commercially available conventional reagents.

[0031] Example 1 (benchmark formulation)

[0032] A multi-effect brightening and firming facial essence, characterized by comprising the following components in percentage by mass: 4.0% of α-arbutin, 8.0% of bifid yeast fermentation broth, 3.0% of palmitoyl pentapeptide-4, 5.0% of glycerol and 80% of a microemulsion system.

[0033] The specific composition of the microemulsion system (total mass is 100%) is as follows:

[0034] Surfactant: Polysorbate 80 1.5%;

[0035] Co-surfactant: ethanol 0.8%, propanol 0.2%;

[0036] Oil phase: Squalane 2.5%, Caprylic / Capric Triglyceride 2.5%;

[0037] Aqueous phase: EDTA 0.05%, hydroxyethyl cellulose 0.2%, appropriate amount of pH regulator to adjust to 5.8-6.0, and distilled water to 100% (about 92.15%).

[0038] The preparation process of the above-mentioned multi-effect brightening and firming facial essence is as follows:

[0039] (a) Premix the active ingredients of α-arbutin, bifid yeast fermentation broth, palmitoyl pentapeptide-4, and glycerol at a temperature not exceeding 30°C (room temperature);

[0040] (b) preparing an oil phase and an aqueous phase separately, dissolving polysorbate 80, ethanol, and propanol in the aqueous phase, and mixing squalane with caprylic / capric triglyceride to prepare the oil phase;

[0041] (c) adding the oil phase dropwise to the aqueous phase at low temperature (room temperature) with continuous stirring and ultrasonic treatment to form a preliminary emulsion;

[0042] (d) using high-energy homogenization equipment (combination of ultrasonic emulsification and high-speed shearing) to treat the emulsion until the particle size is less than 100 nm;

[0043] (e) adding the active ingredient premixed in step (a) to the homogenized microemulsion system obtained in step (d), stirring at a low speed until uniform, and then filling into a light-proof container.

[0044] The facial essence prepared above was tested according to the following test items. The results are shown in Table 1.

[0045] Skin color detection method: 30 healthy volunteers were recruited. Before use, it was ensured that the subjects had not used cosmetics for one consecutive day and their faces were kept clean. The detection instrument was a spectrophotometer (such as Minolta CR-400) and a data acquisition system. During the test, the researchers calibrated the test points on the cheeks or foreheads of the subjects under standardized lighting and room temperature (20-25°C). The L*, a*, and b values were read three times in a row in each designated area and the average was taken. The test was carried out before using the product and after 1, 2, 3, and 4 weeks of continuous use. After the data was collected and sorted, the L values before use and the 4th week after use were compared to calculate the percentage of improvement.

[0046] Skin firmness testing method: 30 volunteers were recruited to participate, with the cheeks or jawline selected as the test area. Participants were asked to maintain a stable facial position before the test. Using a skin elasticity tester (such as the Cutometer or MPA 580) and accompanying data recording software, the tester gently placed a probe on the test area and recorded the immediate deformation and rebound of the skin under standard negative suction pressure. This was repeated two to three times for each area, with the average value taken. All data was collected before product use and after one to four weeks of continuous use. The recovery index data before use was compared with the fourth week to calculate the percentage of improvement.

[0047] Skin moisturizing test method: 30 volunteers were also recruited for the test. Before the test, the subjects were asked to clean their faces and rest for 15 minutes in an ambient temperature of 20-25°C and a humidity of 40%-60% to stabilize the skin condition. A skin capacitance moisture meter (such as Corneometer CM 825) was used for the test. The tester repeated the measurement 3 times in a fixed cheek area and took the average to obtain the moisture content data of the skin surface. The test was arranged before the use of the product and after 1, 2, 3, and 4 weeks of continuous use. Finally, the data before use was compared with the data of the 4th week to calculate the moisturizing improvement rate.

[0048] Stability testing methods: Professional technicians conduct a humidity and heat aging test on at least three batches of product in a 45°C constant temperature oven for 14 days, followed by storage at 25°C for three months. Testing instruments include a high-performance liquid chromatograph (HPLC) for quantifying α-arbutin content, a dynamic light scattering (DLS) for determining microemulsion particle size, and a calibrated pH meter for pH testing. During the test, samples are collected at regular intervals (e.g., at 0, 7, and 14 days), and the changes in each indicator compared to the initial value are calculated. The percentage change is then calculated to evaluate the product's physicochemical stability under different storage conditions.

[0049] Safety testing methods: This was conducted on 30 volunteers who had passed a skin patch test and a long-term local tolerance test. The product was evenly applied to a standardized medical gauze patch and fixed to the subject's forearm or back. After 24 to 48 hours of continuous application, the testers recorded the presence of adverse reactions such as erythema, itching, and edema, using a 0-4 scale to quantify the degree of irritation. Furthermore, the local tolerance test required subjects to use the product daily on a selected area for four consecutive weeks, regularly observing and recording the skin condition and self-reported experiences. Changes were then compared between baseline and post-use. All safety data were statistically verified to show no significant irritation or allergic reactions.

[0050] Table 1 Test data of Example 1

[0051] Time Node Skin color L* value Skin firmness index Skin hydration Before use 65.0 1.25 35.0％ 1 week after use 67.0 1.30 37.0％ 2 weeks after use 69.5 1.35 39.0％ 3 weeks after use 72.0 1.40 41.0％ 4 weeks after use 75.2 1.45 42.0％ Improvement rate 15.7％ 16.0％ 20.0％

[0052] Stability tests showed that under 45°C heat and humidity conditions within 14 days, the α-arbutin content decreased from 4.0% to 3.8% (degradation rate of approximately 5%); the irritation score in the skin patch test decreased from 0.2 to 0.1.

[0053] Example 2 (Oil Phase Replacement)

[0054] On the basis of Example 1, the oil phase in the microemulsion system was entirely replaced with caprylic / capric triglyceride (the total oil phase was maintained at 5.0%) instead of squalane, and the other components and preparation process were the same as those in Example 1.

[0055] Table 2 Test data of Example 2

[0056]

[0057]

[0058] In the stability test, the degradation rate of α-arbutin was about 6%, and the skin irritation score was about 0.15. The overall improvement effect was lower than that of Example 1, indicating that simply replacing the oil phase did not achieve the optimal state.

[0059] Example 3 (Co-surfactant adjustment)

[0060] Based on Example 1, the co-surfactant ratio was adjusted from 0.8% ethanol and 0.2% propanol to a balanced ratio of 0.5% ethanol and 0.5% propanol in an attempt to improve the homogeneity of the microemulsion. The other components and preparation process were consistent with those in Example 1.

[0061] Table 3 Test data of Example 3

[0062] Time Node Skin color L* value Skin firmness index Skin hydration Before use 65 1.25 35.0％ 1 week after use 66.5 1.29 36.5％ 2 weeks after use 68.8 1.33 38.0％ 3 weeks after use 71 1.37 39.5％ 4 weeks after use 73.5 1.42 41.0％ Improvement rate 13.1％ 13.6％ 17.1％

[0063] In the stability test, the degradation rate of α-arbutin was about 5.5%, and the skin irritation score was about 0.12. The overall improvement effect was lower than that of Example 1, indicating that the co-surfactant ratio was not as good as the benchmark formula.

[0064] Example 4 (Adjustment of Bifid Yeast Fermentation Broth)

[0065] Based on Example 1, the concentration of the bifid yeast fermentation broth was increased from 8.0% to 10%, and the other components and preparation process were the same as those in Example 1.

[0066] Table 4 Test data of Example 4

[0067] Time Node Skin color L* value Skin firmness index Skin hydration Before use 65 1.25 35.0％ 1 week after use 67 1.32 37.0％ 2 weeks after use 69.5 1.38 38.8％ 3 weeks after use 72.2 1.45 41.5％ 4 weeks after use 77 1.5 43.0％ Improvement rate 18.5％ 20.0％ 22.9％

[0068] In the stability test, the degradation rate of α-arbutin was about 6.0%, and the skin irritation score increased slightly, but was still within 0.2, meeting safety requirements.

[0069] To verify the impact of key parameters of the present invention's formula on product performance, eight comparative examples were designed. The skin color L* value, skin firmness index, and α-arbutin stability were selected as examples. Data were recorded at various time points before and after use, and the improvement rate between the pre-use and the fourth week after use was calculated. The results are shown in Table 5.

[0070] Comparative Example 1: only comprising 4.0% of α-arbutin and the remainder of basic emulsion (mainly composed of glycerin, corn oil, ceteareth-20, and deionized water).

[0071] Comparative Example 2: only comprising palmitoyl pentapeptide-43.0% and the balance basic emulsion (mainly composed of glycerin, corn oil, ceteareth-20, and deionized water).

[0072] Comparative Example 3: microemulsion system without high-energy homogenization (particle size of about 150 nm).

[0073] Comparative Example 4: The oil phase uses ordinary vegetable oil (olive oil) to replace the professional oil phase.

[0074] Comparative Example 5: The co-surfactant content was reduced to 0.4%.

[0075] Comparative Example 6: The content of the bifid yeast fermentation broth was reduced to 4%.

[0076] Comparative Example 7: Glycerol was removed and the proportion of the microemulsion system was increased accordingly.

[0077] Comparative Example 8: Palmitoyl pentapeptide-4 was removed and the proportion of the microemulsion system was increased accordingly.

[0078] Table 5 Test data of comparative example

[0079]

[0080] From the data in Tables 1 to 5, it can be seen that Example 1 achieved an improvement rate of 15.7%, 16.0% and 20.0% in skin tone improvement, skin firming and moisturizing improvement, respectively, which is the best among all the schemes. Due to factors such as oil phase replacement, co-surfactant adjustment and excessive bifid yeast fermentation broth, Examples 2 to 4 respectively made the improvement of various test data lower than that of Example 1, and some schemes were slightly lacking in stability and safety (such as slightly higher degradation rate and slightly increased irritation score). Therefore, the formula and process parameters of Example 1 can achieve the best skin tone brightening, skin firming and moisturizing effects while ensuring product stability and safety, which is the best technical solution in the present invention.

[0081] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the original invention should also be considered within the scope of protection of the present invention.

Claims

1. Multi-effect brightening and firming facial essence, characterized by: The invention comprises the following components in percentage by mass: 3.0-5.0% of α-arbutin, 8.0-9.0% of bifid yeast fermentation liquid, 3.0-4.0% of palmitoyl pentapeptide-4, 4.0-5.0% of glycerol and the remainder of a microemulsion system; the microemulsion system consists of a surfactant, a co-surfactant, an oil phase and an aqueous phase.

2. The multi-effect brightening and firming facial essence according to claim 1, characterized in that: The invention comprises the following components in percentage by mass: 4.0% of alpha-arbutin, 8.0% of bifid yeast fermentation liquid, 3.0% of palmitoyl pentapeptide, 5.0% of glycerol and the balance of microemulsion system.

3. The multi-effect brightening and firming facial essence according to claim 1, characterized in that: The surfactant in the microemulsion system is polysorbate 80, and its content is 1.0-2.0%.

4. The multi-effect brightening and firming facial essence according to claim 1, characterized in that: The co-surfactant comprises ethanol and propanol, and the total content thereof is 0.7-1.0%.

5. The multi-effect brightening and firming facial essence according to claim 1, characterized in that: The oil phase is selected from squalane and caprylic / capric triglyceride, each of which has a content of 2.5%, and the total oil phase content is 5.0%.

6. The multi-effect brightening and firming facial essence according to claim 1, characterized in that: The aqueous phase consists of distilled water, EDTA, hydroxyethyl cellulose and a pH regulator.

7. A method for preparing a multi-effect brightening and firming facial essence, characterized in that: The following steps are involved: (a) premixing α-arbutin, bifid yeast fermentation broth, palmitoyl pentapeptide-4, and glycerol separately at a temperature not exceeding 30° C.; (b) preparing an oil phase and an aqueous phase separately, wherein polysorbate 80, ethanol, propanol, EDTA, hydroxyethyl cellulose, and a pH adjuster are added to the aqueous phase, and squalane and caprylic / capric triglyceride are mixed into the oil phase; (c) adding the oil phase dropwise to the aqueous phase to form a preliminary emulsion under low temperature conditions, continuous stirring and with the assistance of ultrasound; (d) treating the preliminary emulsion to a microemulsion particle size of less than 100 nm using a high-energy homogenization technique (including ultrasonic emulsification combined with high-speed shearing); (e) adding the active ingredients premixed in step (a) to the microemulsion system obtained in step (d), stirring at a low speed until uniformly mixed, and then filling into a light-proof container.

8. The method according to claim 6, characterized in that The emulsion homogenization process is precisely temperature-controlled and timed to ensure uniform particle size distribution of the obtained microemulsion and system stability.

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