A whitening composition suitable for sensitive skin and its application

Abstract

This invention discloses a whitening composition suitable for sensitive skin and its application, specifically belonging to the field of cosmetic formulations; the composition comprises: palm leaf extract, myrothamnus flabellifolia leaf / stem extract, grape seed extract, and niacinamide; the whitening composition for sensitive skin provided by this invention can effectively inhibit tyrosinase synthesis and has excellent whitening effect; the serum containing the whitening composition for sensitive skin provided by this invention has excellent whitening effect.

Description

Technical Field

[0001] This invention belongs to the field of cosmetics, specifically relating to a whitening composition suitable for sensitive skin and its application. Background Technology

[0002] In recent years, with consumers' increasing demands for skin health and aesthetics, the market size of whitening cosmetics has continued to expand. However, people with sensitive skin face serious challenges in pursuing whitening effects: traditional whitening ingredients (such as high-concentration vitamin C derivatives and fruit acids) can easily cause skin redness, stinging, dryness, and even allergic reactions. Their powerful whitening mechanisms often come at the cost of sacrificing the skin barrier function, leading to further deterioration of sensitivity. In addition, single whitening ingredients have a limited pathway of action, making it difficult to achieve full-chain regulation of melanin production—from "source blocking to metabolic acceleration"—resulting in limited whitening efficiency and a tendency for post-inflammatory hyperpigmentation.

[0003] Current research and development of whitening compositions often focuses on optimizing single targets (such as simply inhibiting tyrosinase activity or promoting exfoliation), neglecting systematic adaptation to the physiological characteristics of sensitive skin. For example, while niacinamide can effectively block the transport of melanosomes to the stratum corneum, its high concentration can easily induce skin intolerance; the strong irritation of plant extracts (such as arbutin and kojic acid) may exacerbate inflammatory reactions in sensitive skin. More importantly, most formulations fail to achieve a synergistic effect between barrier repair and moisturizing functions in sensitive skin, making it difficult for whitening active ingredients to penetrate stably and exert a long-lasting effect, and even causing secondary pigmentation due to skin metabolic environment disturbance.

[0004] To address the aforementioned technical bottlenecks, there is an urgent need to develop a comprehensive whitening system with highly effective whitening and moisturizing effects to provide a safe, gentle, and long-lasting whitening solution for people with sensitive skin. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a composition with whitening effect, wherein the components in the composition have synergistic effect and have significant whitening effect.

[0006] To achieve the above objectives, the present invention discloses the following technical solutions:

[0007] In a first aspect, the present invention provides a whitening composition suitable for sensitive skin, the composition comprising the following components: palm leaf extract, myrothamnus flabellifolia leaf / stem extract, grape seed extract, and niacinamide;

[0008] The mass ratio of palm leaf extract, myrothamnus leaf / stem extract, grape seed extract, and nicotinamide was 1:(1-3):(1.5-2.5):(0.2-0.6).

[0009] Preferably, the mass ratio of the palm-leaf extract, the myrothamnus leaf / stem extract, the grape seed extract, and the nicotinamide is 1:(1-2):(2-2.5):(0.4-0.6).

[0010] More preferably, the mass ratio of the palm-leaf extract, the myrothamnus leaf / stem extract, the grape seed extract, and the nicotinamide is 1:2:2:0.4.

[0011] More preferably, the palmate leaf extract is an aqueous extract of *Rhododendron palmatum*; the *Myrothamnus fruticosa* leaf / stem extract is an alcoholic extract of *Myrothamnus fruticosa* leaves / stems; and the grape seed extract is an alcoholic extract of grape seeds.

[0012] Secondly, the present invention provides the application of the whitening composition for sensitive skin described in the first aspect in the preparation of skin care products.

[0013] Preferably, the skincare product formulation is any one of lotion, cream, serum, eye cream, toner, or mask.

[0014] Thirdly, the present invention provides a whitening serum suitable for sensitive skin, comprising the whitening composition for sensitive skin described in the first aspect, wherein the amount of the whitening composition for sensitive skin added to the serum is 1-5 wt%.

[0015] Preferably, the essence also includes moisturizers, preservatives, emulsifiers, and solvents.

[0016] More preferably, the moisturizer is at least one selected from glycerin, butylene glycol, propylene glycol, 1,2-pentanediol, and dipropylene glycol.

[0017] More preferably, the preservative is p-phenoxyethanol and / or methylparaben.

[0018] More preferably, the emulsifier is at least one of PPG-26-butanol polyether-26, PEG / PPG-17 / 6 copolymer, and glycerol polyether-26.

[0019] More preferably, the solvent is deionized water.

[0020] The beneficial effects of this invention are:

[0021] This invention innovatively combines Palmaria palmata extract, Myrothamnus flabellifolia leaf / stem extract, grape seed extract, and niacinamide to obtain a whitening composition suitable for sensitive skin. Palmaria palmata extract, also known as palmate red algae extract, is rich in essential amino acids and polysaccharides, possessing antioxidant properties, enhancing skin repair capabilities, inhibiting tyrosinase catalysis, and promoting collagen synthesis. Myrothamnus flabellifolia leaf / stem extract contains ceramides, squalene, proanthocyanidins, polyphenols, and flavonoids, exhibiting excellent antioxidant properties, strengthening the skin barrier, and improving stratum corneum metabolism. Grape seed extract is rich in proanthocyanidins, polyphenols, unsaturated fatty acids, and other active substances, possessing tyrosinase inhibition, antioxidant properties, and sebum regulation effects. Niacinamide can inhibit melanin transport to the stratum corneum, reduce pigmentation, promote epidermal cell renewal, and accelerate the shedding of melanin-containing keratinocytes. The four components work together to achieve full regulation of melanin production, transport, and metabolism, resulting in excellent whitening effects. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0024] In this invention:

[0025] raw material Purchased from Product Name Extract categories Palm Leaf Extract Guangzhou Baoyi Biotechnology Co., Ltd. Palm Leaf Extract Water extraction Myrothamnus fruticosa leaf / stem extract Guangzhou Aoxue Chemical Co., Ltd. Myrothamnus fruticosa leaf / stem extract alcohol extract Grape seed extract Guangzhou Lingyu Trading Co., Ltd. - alcohol extract Niacinamide Guangzhou Baihaobo Co., Ltd. Niacinamide - Other raw materials Available for sale - -

[0026] Preparation of whitening compositions suitable for sensitive skin

[0027] By weight, each whitening composition suitable for sensitive skin is obtained by compounding the following components:

[0028] Composition 1: 1 part palm leaf extract, 2 parts myrothamnus flabellifolia leaf / stem extract, 2 parts grape seed extract, 0.4 parts nicotinamide.

[0029] Composition 2: 1 part palm leaf extract, 1 part Myrothamnus flabellifolia leaf / stem extract, 2.5 parts grape seed extract, and 0.2 parts nicotinamide.

[0030] Composition 3: 1 part palm leaf extract, 3 parts myrothamnus flabellifolia leaf / stem extract, 1.5 parts grape seed extract, and 0.6 parts nicotinamide.

[0031] Composition ①: Unlike composition 1, nicotinamide is not added, and the missing mass is made up with deionized water.

[0032] Composition ②: Unlike composition 1, it does not contain Myrothamnus flabellifolia leaf / stem extract, palm leaf extract, or grape seed extract, and the missing mass is made up with deionized water.

[0033] Composition ③: Unlike composition 1, it does not contain Myrothamnus flabellifolia leaf / stem extract or grape seed extract, and the missing mass is made up with deionized water.

[0034] Composition ④: Unlike composition 1, it does not contain palm leaf extract or grape seed extract, and the missing mass is made up with deionized water.

[0035] Composition ⑤: Unlike Composition 1, it does not contain palm leaf extract, and the missing mass of Myrothamnus flabellifolia leaf / stem extract is made up with deionized water.

[0036] Preparation of a whitening serum suitable for sensitive skin:

[0037] The composition of the serum is shown in Table 1. The preparation method of serums 1-5 includes the following steps:

[0038] S1: Heat deionized water to 60°C, add palm leaf extract, myrothamnus leaf / stem extract, and grape seed extract, stir well to obtain a mixture;

[0039] S2: Cool the mixture to 50°C, add humectant, preservative and emulsifier and stir evenly to obtain mixture A;

[0040] S3: After the mixture A has cooled to 40°C, add niacinamide and stir well to obtain a whitening essence suitable for sensitive skin.

[0041] If a component in any of the above steps is not present, deionized water is used to replace that component and it is added instead.

[0042] Table 1. Components of whitening serums suitable for sensitive skin

[0043]

[0044] Note: "-" indicates that the item does not exist.

[0045] Performance testing of whitening compositions suitable for sensitive skin:

[0046] Test samples: serums 1-5, serums ①-⑤, blank.

[0047] Test area:

[0048] Whitening and moisturizing efficacy testing area: entire face

[0049] Stimulation test area: 2×2cm area on the inner side of the forearm of the left or right arm.

[0050] Whitening and moisturizing efficacy test method: Volunteers aged 30-50 years with whitening needs and positive lactic acid stimulation were selected as subjects and evenly distributed into 11 groups of 10 people each. Each group corresponded to a different test sample. During the 28-day trial period, volunteers used the product once a day, with a single application of 3 mL.

[0051] Data collection:

[0052] Data collection on skin whitening efficacy:

[0053] The change in skin melanin content in the test area of ​​the subjects before and after the application of the test sample was evaluated using a skin red melanin analyzer. The measured value was directly proportional to the melanin content. Before applying the test sample, the melanin content in the test area was measured and recorded as M0. On the first day after the end of the experiment, i.e., the 29th day, the melanin content in the test area was measured and recorded as M1. The rate of change of melanin content X was calculated as (M0-M1) / M0×100%, and the results are shown in Table 2.

[0054] Moisturizing data collection:

[0055] On the first day of the experiment, before applying the test sample, the skin moisture content of the test area was measured using a skin moisture meter and recorded as N0. 120 minutes after applying the test sample, the skin moisture content of the test area was measured again and recorded as N1. The 2-hour moisturizing rate = (N1-N0) / N0×100%, and the results are shown in Table 2.

[0056] The melanin or moisture content mentioned in the data collection are all average values ​​within the group.

[0057] Two days before conducting the whitening and moisturizing performance tests, the serum's irritation level was assessed using the following criteria:

[0058] Irritation assessment method: Volunteers aged 30-50 years with whitening needs and positive lactic acid irritation were selected as subjects and evenly distributed into 11 groups of 10 people each. Each group corresponded to one test sample. 0.5 mL of the test sample was applied to the test area of ​​each volunteer. The volunteers' skin condition was observed 30 minutes after using the test sample. If it was negative, the observation continued for 24 hours. If the evaluation criteria were level 2 or above, the experiment was terminated. The results are shown in Table 2.

[0059] Evaluation criteria:

[0060] Grade 0: Negative reaction;

[0061] Grade 1: Suspicious reaction, with only slight erythema;

[0062] Grade 2: Weak positive reaction, erythema, infiltration, edema, and possible papules;

[0063] Grade 3: Strong positive reaction, erythema, infiltration, edema, papules may be present, and the reaction may extend beyond the test area;

[0064] Grade 4: Extremely positive reaction, with obvious erythema, severe infiltration, edema, confluent herpes, and reaction extending beyond the test area.

[0065] Table 2 Performance Test Results

[0066] Group Rate of change X / % Irritation level (level) 2h moisturizing rate / % Serum 1 24.36 0 69.52 Serum 2 10.28 0 46.37 Serum 3 28.72 0 72.33 Serum 4 23.68 0 63.14 Serum 5 24.15 0 63.58 Serum ① 11.64 0 49.55 Serum ② 6.53 0 38.77 Serum ③ 8.72 0 43.36 Essence ④ 9.21 0 45.57 Essence ⑤ 11.67 0 45.14 blank -0.07 0 29.63

[0067] Results analysis:

[0068] According to the test results in Table 2, the essence provided by the present invention has whitening effect. Comparing the results of essences 1 and 4-5, it can be seen that the ratio of the ingredients in the whitening composition suitable for sensitive skin has a certain influence on the whitening and moisturizing effects.

[0069] Comparing the results of serum 1 with serums ①-②, it can be seen that the combined use of palm leaf extract, myrothamnus leaf / stem extract, and grape seed extract with niacinamide can enhance the whitening and moisturizing effects of the composition, and the ingredients in the composition have a synergistic effect.

[0070] Comparing the results of serum ① with serums ②-⑤, it can be seen that, after removing the influence of niacinamide, the combination of palm leaf extract, myrothamnus flabellifolia leaf / stem extract, and grape seed extract can also enhance the whitening and moisturizing effects of the composition. The three together also have a synergistic effect.

[0071] Furthermore, according to the irritation test results, the serum provided by this invention is safe and non-irritating, and is suitable for people with sensitive skin.

[0072] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A whitening serum suitable for sensitive skin, characterized in that, The serum contains the following components by weight percentage: A whitening composition suitable for sensitive skin, 1-5%; Moisturizer 1-3%; Preservative 0.1-0.5%; Emulsifier 0.1-0.5%; Deionized water replenished to 100%; The whitening composition suitable for sensitive skin is composed of the following raw materials: palm leaf extract, myrothamnus flabellifolia leaf / stem extract, grape seed extract, and niacinamide; wherein, the palm leaf extract is an aqueous extract, the myrothamnus flabellifolia leaf / stem extract is an alcohol extract, the grape seed extract is an alcohol extract, and the mass ratio of the palm leaf extract, myrothamnus flabellifolia leaf / stem extract, grape seed extract, and niacinamide is 1:(1-3):(1.5-2.5):(0.2-0.6).

2. The serum according to claim 1, characterized in that, The moisturizer is at least one of glycerin, butylene glycol, propylene glycol, 1,2-pentanediol, and dipropylene glycol; the preservative is phenoxyethanol and / or methylparaben.

3. The essence according to claim 1, characterized in that, The emulsifier is at least one of PPG-26-butanol polyether-26, PEG / PPG-17 / 6 copolymer, and glycerol polyether-26.

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