A composition for sensitive skin, smooth skin, and strong barrier, and use thereof

Abstract

The present application relates to a kind of smooth skin, tough barrier composition suitable for sensitive skin and its application, it is related to the field of cosmetics.The composition includes palmitoyl tetrapeptide-10, dipeptide-15, hexanoyl dipeptide-3 norleucine, Punica granatum protease, ficin and papain-papain protease.The composition does not contain alpha-hydroxy acid, beta-hydroxy acid and hydroxy acid ingredients such as polyhydroxy acid, abandon traditional strong acid exfoliation and mechanical friction, while smoothing pores, smoothing rough skin, restoring skin healthy differentiation track and barrier self-stability ability, realizing instant smooth and long-term tough and recurrence prevention, suitable for long-term safe care of sensitive skin.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and more particularly to a composition for smooth skin and a strong barrier suitable for sensitive skin, and its application. Background Technology

[0002] Follicular plugs, commonly known as "closed comedones" or "acne," are a core pathological link in the formation of rough skin, enlarged pores, and acne. Under normal circumstances, the stratum corneum of the skin undergoes metabolism in approximately 28 days, with aged keratinocytes naturally shedding through the dandruff process. However, influenced by factors such as aging, UV exposure, environmental pollution, unhealthy lifestyle habits, and weakened skin barrier function in sensitive skin, the differentiation and shedding rhythm of keratinocytes becomes disordered, slowing down the shedding process. Excess keratinocytes mix and accumulate at the follicular opening, forming dense plugs that clog pores. This not only makes the skin surface rough and dull, and pores enlarged, but also provides an ideal environment for the proliferation of anaerobic bacteria such as Propionibacterium acnes, thus inducing comedones, papules, and even inflammatory acne.

[0003] Currently, the mainstream technologies for improving pore patency and strengthening the skin barrier in the market can be divided into four categories. The first category is chemical exfoliation, represented by α-hydroxy acids (such as glycolic acid, lactic acid, and glycolic acid) and β-hydroxy acids (such as salicylic acid), which promote keratinocyte exfoliation by chemically dissolving desmosome connections between keratinocytes. The second category is physical scrubs, which rely on products containing exfoliating particles (such as polyethylene microparticles, walnut shell powder, and sea salt particles) to mechanically remove the surface keratin. The third category is acid + enzyme complex exfoliation, represented by hydroxy acids such as lactobionic acid combined with a single protease (such as papain). Although an improvement over single chemical acids, it still relies on acidic components for the main exfoliation force, has a low pH (usually 3.0-4.5), and still poses a risk of irritation to sensitive skin. Furthermore, it lacks a long-term mechanism for endogenously regulating barrier protein synthesis, failing to achieve true dual-pathway synergy. The fourth category is single enzyme preparations, with plant-derived proteolytic enzymes such as papain and bromelain as the main active ingredients, which gently break down keratin through biological enzymatic hydrolysis.

[0004] While the aforementioned technologies have made some progress in improving skin smoothness and strengthening the skin barrier, significant limitations remain. Chemical acids require a low pH environment to function effectively, and under these conditions, they are clearly irritating to the skin barrier, often causing adverse reactions such as redness, stinging, and peeling. Sensitive skin individuals often cannot tolerate them or require a lengthy and painful "tolerance-building" process. Physical exfoliating products remove dead skin cells through mechanical friction; improper use can easily cause micro-damage to the skin, exacerbating barrier dysfunction in sensitive skin. Although enzymatic hydrolysis is relatively gentle, the efficacy of single enzyme preparations is often limited to surface exfoliation, failing to penetrate deep into the hair follicle to dissolve complex plugs mixed with keratin and sebum, and lacking a long-term mechanism to promote the normalization of keratin metabolism. More importantly, existing technologies largely rely on external force for "passive" exfoliation, failing to intervene in the differentiation process of keratinocytes. This not only fails to promote the production of barrier-related structural proteins to strengthen new keratinocytes but also easily weakens barrier integrity during the exfoliation process, leading to recurring keratin buildup and sensitivity problems after discontinuation. Follicular plugs are complex blockages formed by a mixture of keratin (a protein) and sebum (a lipid). Single proteases can only break down keratin components and cannot effectively hydrolyze simple lipid components such as triglycerides in sebum. However, it is known in the art that in the microenvironment of the follicular opening, unsaturated fatty acids in sebum are easily oxidized. The resulting oxidized lipids can undergo Michael addition reactions with keratin sulfhydryl groups, forming a dense cross-linked network structure, which further increases the mechanical strength and chemical stability of the plugs. With the increasing number of people with sensitive skin, the problems of barrier damage, nerve ending sensitization, and recurrent microcomedone formation caused by traditional exfoliation strategies are becoming increasingly prominent. There is an urgent need to develop a gentle keratin regulation system that can simultaneously regulate healthy keratin differentiation, promote the production of strong barrier proteins, restore the natural exfoliation process, and exogenously target and clear blockages. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a composition for smooth skin and a strong barrier suitable for sensitive skin, and its application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a composition for smooth skin and a strong skin barrier suitable for sensitive skin, characterized in that it comprises a peptide component and a protease component in a mass ratio of (0.01-2):(0.1-3); the peptide component comprises palmitoyl tetrapeptide-10, dipeptide-15, and hexanoyl dipeptide-3 leucine in a mass ratio of (1-2):(1-2):(2-4); and the protease component comprises punicic acid protease, figase, and papain-bromelain in a mass ratio of (1-2):(0.1-1):(1-3).

[0007] The composition of this invention, suitable for sensitive skin and providing a smooth skin barrier, comprises the following components: Palmitoyl tetrapeptide-10, a palmitic acid-modified synthetic signal peptide rich in hydrophobic anchoring groups, which activates endogenous KLK5 expression in keratinocytes and regulates the transcription of keratin differentiation-related genes, thereby initiating physiological keratin metabolism, promoting the production of barrier structural proteins, and restoring the skin's natural exfoliation process; and dipeptide-15, rich in high-affinity amino acid sequences, which softens abnormal keratin by optimizing the keratin cross-linking network and intercellular adhesion. It has the effects of accumulating and strengthening newly formed keratinocytes and smoothing rough skin texture; the hexanoyl dipeptide-3 leucine is a biomimetic penetration-enhancing peptide that enhances the delivery of active ingredients across the stratum corneum and synergistically regulates the keratinization and differentiation of hair follicle ducts, thereby unclogging microcomedones and improving the microenvironment of hair follicles; the pomegranate protease is rich in polyphenols such as ellagic acid and punicalin, and its lipophilic polyphenol backbone can insert into the keratin-lipid cross-linking interface, destroying covalent cross-links through hydrogen bonds and π-π stacking, disintegrating the keratin plug structure, and exposing keratin for protease hydrolysis. This effect does not depend on lipase activity. The ficin enzyme is derived from the latex of figs (Ficus carica) and belongs to the cysteine ​​protease family. It specifically hydrolyzes the peptide bonds of desmoglein, a glycoprotein between keratinocytes, thus gently loosening the connections between keratinocytes, promoting natural exfoliation, and having low sensitization. The papain-bromelain enzyme is a compound enzyme preparation composed of papain and bromelain in a 1:1 mass ratio. After optimization of enzyme activity balance, it synergistically expands the hydrolytic substrate spectrum and stabilizes the pH adaptation range, resulting in a highly efficient, clear, and low-sensitization compound exfoliation effect. The aforementioned peptides and proteome initiate physiological desquamation through endogenous regulation of differentiation and promotion of barrier proteins, while exogenous enzymes precisely exfoliate surface keratin and follicular plugs, forming a gentle yet systematic keratin regulation network. The composition works under near-neutral pH conditions (5.5-6.5) and does not contain hydroxy acid components such as α-hydroxy acids (such as glycolic acid and lactic acid), β-hydroxy acids (such as salicylic acid), and polyhydroxy acids (such as lactobionic acid), thus avoiding the irritation that may be caused by traditional strong exfoliating ingredients. It is especially suitable for long-term safe use by people with sensitive skin.

[0008] The composition utilizes a dual synergistic mechanism of "endogenous regulation of keratin differentiation and physiological desquamation program + exogenous gentle exfoliation of keratin plugs at the hair follicle opening" to systematically intervene from both the physiological and environmental levels of the skin and the hair follicle. Specifically, it includes: (1) Endogenous promotion and program reset: using signal peptides such as palmitoyl tetrapeptide-10, it not only activates the expression of endogenous keratin renewal enzymes such as KLK5 in keratinocytes, but also precisely regulates the differentiation trajectory of keratinocytes and promotes the synthesis of key barrier structural proteins such as filaggrin. This mechanism makes the newly formed keratinocytes more tightly arranged and stronger in structure, fundamentally correcting abnormal keratinization, allowing the skin to return to a healthy and regular natural exfoliation program, and achieving long-lasting smooth skin texture and barrier self-stabilization; (2) Exogenous gentle exfoliation: using the synergistic combination of three enzymes, pomegranate protease, figase and papain-bromelain, it gently and precisely decomposes the keratin components and oxidized lipid complexes in the keratin plugs at the hair follicle opening, unblocks the hair follicle opening, makes the pores clear, and immediately reduces acne induced by hair follicle blockage.

[0009] In summary, the composition of this invention, through the aforementioned dual-pathway design of "internal regulation + external exfoliation," achieves organic complementarity in its mechanism of action: peptide components reshape keratinocyte differentiation and metabolic rhythm at the cellular level, strengthening newly formed keratinocytes and restoring the natural shedding process, fundamentally dismantling the physiological basis for keratin plug formation; enzyme components rapidly clear existing keratin plugs from the hair follicle opening, instantly improving skin smoothness and pore patency. This synergistic internal and external approach addresses both the symptoms and the root cause, achieving the dual technical effects of "immediate smoothing and clearing blockages" and "long-lasting strengthening and prevention of recurrence." Furthermore, all active components in the composition are biologically derived peptides and enzymes, with a mechanism of action based on signal regulation and enzymatic catalysis. The composition is completely free of any hydroxy acids such as α-hydroxy acids (AHA), β-hydroxy acids (BHA), and polyhydroxy acids (PHA), and can exert its efficacy under near-neutral pH conditions (5.5-6.5), requiring no strong acid / alkali environment and not relying on mechanical friction. Its low-irritation formula makes it suitable for long-term safe use by people with sensitive skin. Compared with existing acid + enzyme + peptide complex skin resurfacing solutions, this invention fundamentally eliminates the potential damage risk to the skin barrier caused by acidic exfoliating ingredients. At the same time, it actively repairs and strengthens the skin barrier through the endogenous regulatory effect of peptides, achieving a technological breakthrough of simultaneous exfoliation and repair.

[0010] Furthermore, the mass ratio of the peptide component to the protease component is (0.1-1):(0.5-2).

[0011] Furthermore, the mass ratio of the peptide component to the protease component is (0.3-0.5):(1-1.5).

[0012] Furthermore, the papain-bromelain is an enzyme preparation obtained by combining papain and bromelain in a mass ratio of 1:1.

[0013] In a second aspect, the present invention provides the use of the composition described in the first aspect in the preparation of cosmetics.

[0014] Furthermore, the cosmetics include toners, lotions, creams, masks, serums, or freeze-dried powders.

[0015] Preferably, the cosmetic is a toner.

[0016] Furthermore, the amount of the composition added to the cosmetic is 1wt%-3wt%.

[0017] Thirdly, the present invention provides a cosmetic product suitable for sensitive skin that provides smooth skin and a strong barrier, the cosmetic product comprising the composition described in the first aspect.

[0018] Fourthly, the present invention provides a cosmetic water comprising the following ingredients by weight percentage: 1%-3% of the composition described in the first aspect, 0.1%-1% of a thickener, 2%-15% of a moisturizer, 0.01%-0.3% of a pH adjuster, 0.1%-1% of an antioxidant, and the balance being deionized water.

[0019] Furthermore, the lotion comprises at least one of the following (a)-(d): (a) The thickener comprises at least one of the following: polyacrylate crosspolymer-6, carbomer, carrageenan, gellan gum, xanthan gum, microcrystalline cellulose, ammonium acryloyl dimethyl taurate / VP copolymer, and acrylate copolymers; (b) The moisturizer comprises at least one of the following: glycerin, butylene glycol, 1,2-hexanediol, 1,3-propanediol, 1,2-pentanediol, panthenol, caprylyl glycol, dipropylene glycol, tremella polysaccharide, trehalose, betaine, allantoin, hyaluronic acid, sodium hyaluronate, acetylated sodium hyaluronate, hydrolyzed sodium hyaluronate, sodium hyaluronate crosspolymer, β-glucan, and ceramide. (c) The pH adjuster is arginine; (d) The antioxidant is p-hydroxyacetophenone.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a composition suitable for sensitive skin that promotes smooth skin and strengthens the skin barrier, comprising three peptide components and three enzyme components. The invention proposes a dual-pathway synergistic mechanism of endogenous regulation of keratin differentiation and exogenous enzymatic targeted clearing of blockages: The endogenous pathway activates the expression of KLK5 / endogenous keratin renewal enzyme through signal peptides such as palmitoyl tetrapeptide-10, promoting the production of barrier structural proteins such as filaggrin, restoring the normal rhythm of keratin metabolism, and restarting the natural exfoliation process, achieving long-lasting strength and preventing recurrence. The exogenous pathway, through the synergistic combination of three enzymes—papaya-bromelain—targets and breaks down complex keratin plugs formed by the cross-linking of keratin and oxidized lipids at the hair follicle opening. It disrupts the cross-linking network through polyphenol-protein interactions, simultaneously cooperating with proteases to hydrolyze the exposed keratin core, achieving overall resolution of keratin plugs and immediate smoothing and clearing of blockages. The two pathways complement each other synergistically in terms of time (immediate vs. long-lasting) and action, overcoming the dilemma of existing technologies where exfoliation damages the skin barrier and repair fails to clear blockages. More importantly, this composition is completely free of hydroxy acids and achieves gentle and systematic keratin regulation under near-neutral pH conditions (5.5-6.5), making it particularly suitable for long-term safe use on sensitive skin. Attached Figure Description

[0021] Figure 1 Images showing the effects of the toner on the arms of volunteers after using it in Application Example 1, Comparison Example 1, 11 and Blank Application Example, at the beginning of use, after 5 days and 12 days; Figure 2 The improvement of facial scaling in volunteers after using the toners from Application Example 1 and the blank application example for 14 days. Detailed Implementation

[0022] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0023] The materials used in the following embodiments and comparative examples are from the following sources: Palmitoyl tetrapeptide-10 was purchased from Redlin Company, under the trade name Crystal Highlight Peptide; Dipeptide-15 was purchased from Guangzhou Best Chemical Co., Ltd., under the trade name ReClear™ D15; Hexanoyl dipeptide-3-leucine was purchased from Vichi Biotechnology Co., Ltd., under the trade name fruit acid peptide. Papaya-bromelain was purchased from Shanghai Boshuo Industrial Co., Ltd. (enzyme activity ≥1000U / mg). The pomegranate protease was purchased from Guangzhou Nuoran Biotechnology Co., Ltd., under the product name ACB Modified Pomegranate Enzyme PF (enzyme activity ≥500U / mg). The fig enzyme was purchased from Shanghai Boshuo Industrial Co., Ltd., and its product name is Fig Protease Extract (enzyme activity ≥1000U / mg). Mandelic acid was purchased from Nacon Biotechnology Co., Ltd. Papain was purchased from Lipotec under the trade name Peelmoist™.

[0024] Unless otherwise specified, all other materials and reagents used in the examples and comparative examples are commercially available.

[0025] Example 1 This embodiment provides a composition for smooth skin and a strong skin barrier suitable for sensitive skin. The composition includes peptides and proteases in a mass ratio of 0.5:1.2. The peptides include palmitoyl tetrapeptide-10, dipeptide-15, and hexanoyl dipeptide-3 leucine in a mass ratio of 1.5:1.5:3. The proteases include punicin, figase, and papain-bromelain in a mass ratio of 1.5:0.5:2.

[0026] Example 2 This embodiment provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of peptide components to protease components is 0.3:1.0, while the other parameters are the same as those of Example 1.

[0027] Example 3 This embodiment provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of peptide components to protease components is 0.5:1.5, while the other parameters are the same as those of Example 1.

[0028] Example 4 This embodiment provides a composition for smooth skin and a strong skin barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of peptide components to protease components is 0.1:0.5, while the other parameters are the same as those of Example 1.

[0029] Example 5 This embodiment provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of peptide components to protease components is 1:2.0, while the other parameters are the same as those of Example 1.

[0030] Example 6 This embodiment provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of peptide components to protease components is 0.01:0.1, while the other parameters are the same as those of Example 1.

[0031] Example 7 This embodiment provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of peptide components to protease components is 2.0:3.0, while the other parameters are the same as those of Example 1.

[0032] Example 8 This embodiment provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of palmitoyl tetrapeptide-10, dipeptide-15, hexanoyl dipeptide-3 leucine in the peptide components is 1:1:2, and the mass ratio of pomegranate protease, figase, and papain in the protease components is 1:0.1:1.

[0033] Example 9 This embodiment provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and that of Example 1 is that the mass ratio of palmitoyl tetrapeptide-10, dipeptide-15, hexanoyl dipeptide-3, and ortholeucine in the peptide components is 2:2:4, and the mass ratio of pomegranate protease, figase, and papain in the protease components is 2:1:3.

[0034] Comparative Example 1 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that the mass ratio of peptide components to protease components is 3:0.001, while the other parameters are the same as in Example 1.

[0035] Comparative Example 2 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that the mass ratio of peptide components to protease components is 0.001:4, while the other parameters are the same as in Example 1.

[0036] Comparative Example 3 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that no peptide components are added. The missing amount is made up by pomegranate protease, fig enzyme and papain-bromelain in a mass ratio of 1.5:0.5:2. The other parameters are the same as those in Example 1.

[0037] Comparative Example 4 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that it does not contain any protease-like components. The missing components are made up by palmitoyl tetrapeptide-10, dipeptide-15, and hexanoyl dipeptide-3 leucine in a mass ratio of 1.5:1.5:3. All other parameters are the same as in Example 1.

[0038] Comparative Example 5 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that palmitoyl tetrapeptide-10 is not added to the peptide components. Its missing amount is made up by dipeptide-15 and hexanoyl dipeptide-3 leucine in a mass ratio of 1.5:3. The other parameters are the same as those in Example 1.

[0039] Comparative Example 6 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that dipeptide-15 is not added to the peptide components. The missing amount is made up by palmitoyl tetrapeptide-10 and hexanoyl dipeptide-3 leucine in a mass ratio of 1.5:3. The other parameters are the same as those in Example 1.

[0040] Comparative Example 7 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that the peptide component does not contain hexanoyl dipeptide-3 leucine, and its missing amount is made up by palmitoyl tetrapeptide-10 and dipeptide-15 in a mass ratio of 1.5:1.5. The other parameters are the same as those in Example 1.

[0041] Comparative Example 8 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that pomegranate protease is not added to the protease component. The missing amount is made up by fig enzyme and papain-bromelain in a mass ratio of 0.5:2. The other parameters are the same as in Example 1.

[0042] Comparative Example 9 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that fig enzyme is not added to the protease component, and its missing amount is determined by pomegranate protease and papain-bromelain in a mass ratio of 1.5:2. All other parameters are the same as in Example 1.

[0043] Comparative Example 10 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that the papain-bromelain component is not added, and its missing amount is determined by pomegranate protease and figase in a mass ratio of 1.5:0.5. The other parameters are the same as in Example 1.

[0044] Comparative Example 11 This comparative example provides a composition for smooth skin and a strong skin barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that no peptide components are added to this composition, and the missing amount is made up with an equal mass of mandelic acid. All other parameters are the same as those in Example 1.

[0045] Comparative Example 12 This comparative example provides a composition for smooth skin and a strong barrier suitable for sensitive skin. The only difference between this composition and Example 1 is that no protease component is added to this composition. Instead, the missing amount is made up with an equal mass of papain. All other parameters are the same as in Example 1.

[0046] Test Example 1 1. The ability of the composition to promote the in vitro production of skin endogenous enzyme systems and barrier proteins. KLK5 is a core serine protease that regulates the degradation of desmosomes in keratinocytes and physiological desquamation. FLG (figrin) is a core protein of the skin barrier. After sample treatment, the more significant the upregulation of the mRNA expression levels of the KLK5 and FLG genes, the stronger the composition's ability to activate endogenous keratin metabolism pathways, promote the physiological shedding of old and dead keratinocytes, and promote the strengthening of new keratinocytes.

[0047] Test substance preparation: The compositions (Examples 1-9 and Comparative Examples 1-12) were diluted to 0.5% using DMEM complete culture medium containing 10% fetal bovine serum as the final experimental concentration, and recorded as the sample solution. They were prepared and used immediately.

[0048] The cell line used in this invention is human immortalized keratinocyte HaCaT (Beina Biotechnology). The test conditions are: incubator temperature of 37±1℃, saturated humidity, and carbon dioxide of 5±1%.

[0049] Test method: Real-time quantitative PCR (qRT-PCR) detection, details as follows: Cell seeding and treatment: Inoculate the cell suspension at 1 × 10⁶ cells per dish. 6 Cells were seeded at a density of [number] cells per 60 mm cell culture dish and cultured in DMEM complete medium containing 10% fetal bovine serum for 24 hours until cell confluence reached approximately 80%. Before UVB irradiation, the medium was replaced with 1.5 mL of PBS per dish. Cells were cultured in uncovered plastic dishes with UVB at 30 mJ / cm². 2Irradiate at 312 nm. After irradiation, remove PBS and replace with fresh culture medium. Add 5 mL of complete culture medium containing the sample solution to each sample group, and replace the blank group with an equal volume of 5 mL of complete culture medium without the sample. Place the culture dishes back into the incubator and continue culturing for 24 h.

[0050] Cell collection and RNA extraction: 24 h after drug treatment, discard the culture medium, wash cells once with PBS, add 1 mL of TRIzol lysis buffer to each dish, lyse the cells thoroughly, collect the lysis buffer in RNase-free EP tubes, and store at -80℃ or immediately extract total RNA using the standard chloroform method. RNA concentration and purity (A260 / A280 = 1.8–2.0) were determined using NanoDrop.

[0051] cDNA synthesis: Genomic DNA removal and reverse transcription were performed using the PrimeScript RT reagent Kit with gDNA Eraser (TaKaRa, catalog number RR047A). 1 μg of total RNA was reverse transcribed into cDNA and stored at -20℃ for later use.

[0052] qRT-PCR assay: Amplification was performed using TB Green Premix Ex Taq II (TaKaRa, catalog number RR820A) on a Bio-Rad CFX96 real-time PCR instrument. The reaction volume was 20 μL, including 10 μL TB Green Premix, 0.8 μL each of forward and reverse primers, 2 μL cDNA template, and 6.4 μL sterile water. The reaction program was: 95℃ pre-denaturation for 30 seconds; 95℃ denaturation for 5 seconds, 60℃ annealing / extension for 30 seconds, for a total of 40 cycles. Melting curve analysis was used to verify amplification specificity.

[0053] The KLK5 sequence is as follows: upstream: 5'-GCT GGA GCA GAA TGA GAA GC-3', downstream: 5'-TCC AGGTGA AGG AGA TGA GC-3'.

[0054] FLG sequence: upstream: 5'-GCT GCA GGA GGA CAA GAA GA-3', downstream: 5'-TCC AGC TCC TCCTCT TCT TC-3'.

[0055] Internal reference gene (GAPDH): Upstream: 5'-GGA GCG AGA TCC CTC CAA AAT-3', Downstream: 5'-GGCTGT TGT CAT ACT TCT CAT GG-3'.

[0056] The prokinetic activity of the composition against serine proteases was represented by the upregulation of the KLK5 gene, and the barrier-strengthening effect of the composition was represented by the upregulation of the FLG gene. The calculation formulas are as follows: Promotion rate (%) = [(Relative expression level of sample group - relative expression level of blank group) / relative expression level of blank group] × 100%; The higher the KLK5 promotion rate, the better the effect of the composition on activating the skin's endogenous enzyme system. The higher the FLG promotion rate, the stronger the composition's effect on skin barrier strengthening. The calculated results are shown in Table 1. 2. In vitro selective test of follicular plug dissolution and gentle exfoliation Follicular plug blockage is a core physical factor leading to microcomedones and acne recurrence. A higher dissolution rate of the composition for keratin plugs indicates a stronger ability to clear follicular micro-blockages and unblock sebum excretion channels. Simultaneously, lactate dehydrogenase (LDH) is a stable metabolic enzyme widely present in the cytoplasm of living cells. In a healthy state, it is tightly encapsulated by the intact cell membrane and cannot escape. When exogenous components (such as enzymatic exfoliants, acids, or permeation-enhancing peptides) excessively penetrate, disrupt the lipid barrier, or directly damage the living cell membrane, cell membrane permeability increases, and even necrosis / lysis occurs, causing LDH to passively leak into the extracellular environment (bottom culture medium). Therefore, lower damage to the cell damage marker lactate dehydrogenase (LDH) in recombinant epidermal models indicates a superior gentleness and selectivity of its "exogenous enzymatic exfoliation - endogenous peptide renewal" system for sensitive skin, providing in vitro evidence for safe clearing of blockages in sensitive skin.

[0057] Test substance preparation: The compositions (Examples 1-9 and Comparative Examples 1-12) were diluted to 0.5% using phosphate-buffered saline (PBS) at pH 5.5±0.2 as the final experimental concentration and recorded as the sample solution. They were prepared and used immediately.

[0058] The model used in this invention is a recombinant human epidermal model (RHE, EPI-200) purchased from MatTek Corporation and a commercially available standardized artificial hair follicle plug testing module (Mimic FluiX, catalog number: MSB03008). The testing conditions are: constant temperature shaking incubator 37±1℃, relative humidity ≥90%.

[0059] Test method: (1) Artificial keratin plug dissolution experiment: The purchased artificial keratin plug test module was vertically fixed in a 24-well plate, and 2 mL of the corresponding sample solution was added to each well. A blank control group (only an equal volume of PBS was added) was set up. The plate was incubated in a constant temperature shaker at 37℃ (80 rpm) for 4 h. The module was removed, and the undissolved residue on the surface was gently rinsed with deionized water. The module was then dried at 60℃ to constant weight. The difference in dry weight of the module before and after dissolution was measured using a precision electronic balance.

[0060] (2) Mild exfoliation selectivity test (RHE model): Principle: Applying the sample to the surface of the RHE model for 15 minutes simulates the short-term contact of daily skincare products or the initial contact state during product use. The LDH collected from the underlying culture medium originates only from the lower layer of live cells in the model; the keratinized and dead keratinocytes on the surface do not contain intact cytoplasm and do not contribute LDH signal. Therefore, this indicator specifically reflects the degree of damage to epidermal live cells.

[0061] The specific method is as follows: The RHE model was placed in a 6-well plate containing 1 mL of culture medium. For the sample group, 50 μL of the corresponding sample solution was evenly spread on the surface of each well. For the blank group, an equal volume of PBS was spread, and for the positive group, 50 μL of a solution containing 10% Triton X-100 was spread. After incubation at 37℃ for 15 min, the samples were removed, and the model surface was gently washed twice with pre-warmed PBS to terminate the reaction. The culture medium from the bottom of each well was collected, and the absorbance (OD value) was measured at 490 nm, strictly following the instructions of the LDH cytotoxicity assay kit (catalog number: C0016, Beyotime). This OD value represents the LDH release value for the corresponding group. The model was fixed with 4% paraformaldehyde for 24 h. After fixation, H&E staining was performed, and the model was photographed under a microscope to collect epidermal morphology information.

[0062] The composition’s ability to remove keratin plugs and its gentleness are expressed by the keratin plug dissolution rate and cell damage rate.

[0063] Corneal plug dissolution rate (%) = [(initial dry weight of corneal plug - dry weight after dissolution) / initial dry weight of corneal plug] × 100%; Cell damage rate (%) = [(LDH release value of sample group - LDH release value of blank group) / (LDH release value of positive control group - LDH release value of blank group)] × 100%, and the results are shown in Table 1.

[0064] As shown in Table 1, the compositions provided in Examples 1-9 of this invention have significant effects on activating the skin's endogenous enzyme system and strengthening the skin barrier. The KLK5 promotion rate and FLG promotion rate of the composition in Example 1 of this invention are significantly different from those in Comparative Examples 1-2, indicating that compared with the comparative examples that removed a single component, replaced it with mandelic acid / papain, or adjusted the dosage ratio, the composition of this invention can significantly activate the serine protease KLK5 pathway of keratinocytes and greatly enhance the expression of the barrier core protein FLG.

[0065] Analysis of the data on keratin plug dissolution rate and cell damage rate shows that the composition of the present invention maintains a high keratin plug dissolution rate while controlling the cell damage rate at an extremely low level, demonstrating the gentle advantage of the "exogenous enzymatic exfoliation-endogenous peptide renewal" system for sensitive skin. Furthermore, data from Example 1 and Comparative Examples 1-12 indicate that the combination of peptide and protease components in the composition provided by the present invention achieves both high-efficiency keratin plug dissolution and gentleness, making it suitable for use on sensitive skin.

[0066] Table 1 Example 1 108.7 158.6 83.1 1.9 Example 2 104.2 149.3 77.2 3.0 Example 3 107.6 154.1 81.5 2.1 Example 4 100.0 143.8 73.9 4.6 Example 5 103.5 147.4 75.8 3.9 Example 6 93.1 133.2 66.3 6.8 Example 7 98.3 139.5 70.4 5.2 Example 8 106.8 150.0 79.6 2.8 Example 9 105.4 155.3 81.1 2.5 Comparative Example 1 77.1 89.9 26.4 12.7 Comparative Example 2 42.5 68.1 38.6 21.5 Comparative Example 3 33.8 67.3 35.3 22.1 Comparative Example 4 52.2 70.0 20.1 13.3 Comparative Example 5 64.7 81.4 34.5 15.6 Comparative Example 6 68.9 81.8 32.8 14.4 Comparative Example 7 71.0 83.6 30.7 13.9 Comparative Example 8 73.6 86.0 29.2 17.7 Comparative Example 9 73.3 86.2 29.0 17.2 Comparative Example 10 76.8 88.1 26.7 16.5 Comparative Example 11 60.4 63.5 40.6 28.1 Comparative Example 12 63.2 71.8 37.2 20.7 Application Example 1-9 and Comparative Application Example 1-12 The compositions of Examples 1-9 and Comparative Examples 1-12 were added to the toner at a concentration of 1.5 wt% to obtain the toners of Application Examples 1-9 and Comparative Application Examples 1-12; the toner formulations are shown in Table 2.

[0067] Table 2. Components and Dosage of Toner

[0068] The preparation method of the lotion includes the following steps: S1. Mix the thickener and humectant 1 evenly, add deionized water, heat to 75±5℃, homogenize, keep warm for later use, and obtain component A. S2. Mix humectant 2 and antioxidant, heat to 60±2℃ to melt, and obtain pre-prepared component B. S3. After cooling the pre-prepared component A to 60±2℃, add the pre-prepared component B at 250 rpm and stir to mix. Then cool to 40℃, add the corresponding composition and continue stirring for 8 minutes. Finally, add a pH adjuster to adjust the pH to 5.5, then stop stirring, discharge the material, and obtain the cosmetic lotion.

[0069] The present invention also provides a cosmetic water for blank application examples, which differs from application example 1 only in that the cosmetic water does not contain the composition, but is supplemented with an equal mass of deionized water to make up for its missing amount, while the other parameters and preparation methods are the same as those in application example 1.

[0070] Test Example 2: Human Skin Patch Test To rigorously verify the high safety and gentleness of this product for sensitive skin, this study designed and implemented an enhanced human closed patch trial. The trial recruited 28 volunteers aged 20 to 50 years (50% of whom reported having sensitive skin), and all participants signed informed consent forms. Subsequently, 0.025 mL of test samples (toners from Application Examples 1-9 and Control Application Examples 1-12), toners from blank application examples, and purified water (negative control) were placed in 12-well patch apparatuses (with two cut wells fixed below a 10-well plate) and applied to pre-treated skin using hypoallergenic adhesive tape for 24 hours. Skin reactions were observed and recorded by professional evaluators at 0, 24, and 48 hours after patch removal, according to criteria (no reaction 0 points, slight erythema 1 point, moderate erythema 2 points, severe erythema with edema 3 points, and very severe reaction 4 points). The final safety assessment criterion is as follows: if the average irritation score of the application group is not higher than that of the blank control group, and no adverse reactions of grade 2 or above occur, then the product is considered safe and non-irritating, and suitable for sensitive skin. Adverse skin reaction grades are shown in Table 3 below.

[0071] Table 3 0 negative reaction 1 Suspicious reaction, only slight erythema 2 Weak positive reaction (erythema reaction): erythema, infiltration, edema, and papules may be present. 3 Strong positive reaction (herpes reaction): erythema, infiltration, edema, papules; the reaction may extend beyond the test area. 4 Extremely strong positive reaction (confluent herpes simplex reaction): obvious erythema, severe infiltration, edema, confluent herpes simplex; reaction extends beyond the test area. After testing, the toners provided in Application Examples 1-9, Comparative Application Example 1, Comparative Application Examples 4-10, Comparative Application Example 12, and the blank application example all showed negative reactions after human patch testing, indicating they are safe and non-irritating to human skin. However, Comparative Application Example 2 showed one Grade 2 reaction, Comparative Application Example 3 showed two Grade 2 reactions, and Comparative Application Example 11 showed two Grade 2 reactions and one Grade 2 reaction, posing a certain safety risk and therefore not contributing to the subsequent facial efficacy.

[0072] Test Example 3 1. Composition keratin renewal and skin smoothing test This experiment used dihydroxyacetone (DHA) staining to quantitatively evaluate the ability of the composition of this invention to promote physiological renewal of the stratum corneum and improve rough skin texture. DHA reacts with free amino acids in the stratum corneum to generate a brownish pigment, which gradually fades as the stratum corneum naturally exfoliates. The faster the sample promotes stratum corneum renewal, the greater the degree to which the skin color in the test area returns to its initial state, and the more significant the skin smoothing effect.

[0073] Subjects and Grouping: Healthy volunteers aged 18-60 years were recruited. Initial skin tone ITA° > 20 was required at the test site (flexor side of the forearm), with no inflammation / scarring / pigmentation / hirsutism, and no recent use of physical or chemical peeling products. Eight valid subjects were assigned to each group, divided into four groups, for a total of 32 subjects. Test areas were symmetrically marked on both arms, with a blank control included. Four test areas were marked on each arm, and three samples and a blank control were added for measurement, thus allowing for six samples to be measured per group. Subjects in each group were randomly assigned to use samples from Examples 1-9, control sample 1, control samples 4-12, and a blank control group.

[0074] Test process: D0 (before staining): Cleanse both arms with water in the morning and sit quietly for 30 minutes. Mark four 6cm² (2×3cm) test areas on each arm with a skin marker (interval ≥1cm). Take baseline images using VISIA and record ITA° values.

[0075] Staining and modeling: Apply 2.0 mg / cm² of 5% dihydroxyacetone cream (stored at 4°C) evenly to the test area, and repeat the application once after 4 hours (do not rinse during this period). During staining, the test area must not be washed, rubbed, or have any cleaning / moisturizing products used.

[0076] D0' (48h after staining): Images of the stained area were captured using VISIA, and the ITA° values ​​of each region were recorded as the staining baseline before sample application.

[0077] Sample application: Apply each test sample evenly to the corresponding area at a concentration of 2.0 mg / cm², at least twice a day (with an interval of ≥4 hours), for 12 consecutive days.

[0078] Follow-up visits were conducted on days 5 and 12 after sample use, with repeated VISIA polarized light imaging and data acquisition.

[0079] The SCRR (Semen Renewal Rate) is calculated as follows: SCRR (Semen Renewal Rate) = (ITAi - ITAo) / (ITA before staining - ITAo) × 100%; In the formula: ITAi—The ITA° value of the color spot at each measurement time point after the sample has been used; ITAo – Baseline ITA° value of pigmentation after 48 hours of treatment with dihydroxyacetone cream; Pre-ITA staining – Initial ITA° value of the skin before staining The formula reflects the degree of color fading. The higher the SCRR value, the faster the keratin exfoliation and renewal, and the smoother the skin texture. The results are shown in Table 4.

[0080] 2. Assessment of skin pore reduction, oil control, repair, and smoothness improvement Seventy-six Asian adult volunteers aged 20-45 years were recruited to participate in the trial. Those who were initially screened by questionnaires as having oily / combination skin and who reported excessive facial oil, large pores, rough skin texture, and sensitive skin (lactate sting test score ≥3) were randomly divided into 19 groups (experimental group: application cases 1-9, control group: application case 1, control group: application cases 4-10, control group: application case 12, and blank group: blank application case), with 4 people in each group (meeting the requirements for statistical efficacy testing).

[0081] Under normal circumstances, volunteers continuously used the corresponding product on their entire face for 14 days. Every morning and evening after gentle cleansing, they took about 1.0g of the corresponding sample and applied it evenly to their face, gently massaging until fully absorbed. The product was used on the entire face once in the morning and once in the evening. Other functional skin care products were discontinued during the use period. Data was collected during follow-up visits on day 0 (baseline) and day 14.

[0082] On the day of the volunteers' visit, the test area was cleansed only with water or a mild facial cleanser, without the application of any skincare products. The volunteers sat quietly for 30 minutes in a constant temperature and humidity laboratory (21±1℃, 50±10%) to allow their skin's physiological state to stabilize before instrument testing. Standardized instruments were used to objectively assess the improvement in facial skin: Pore size: Antera 3D imaging was used to analyze the total volume of skin pores. Sebum secretion (oil control): A Sebumeter® SM 815 (Courage & Khazaka, Germany) probe was gently placed on the center of the forehead to read the sebum absorption rate and convert it into sebum volume (μg / cm²). Transepidermal water loss (repair): The Tewameter® TM Hex (Courage & Khazaka, Germany) probe was used to measure the TEWL value (g / m²·h) in the cheek area; a decrease in the value indicated an enhanced skin barrier's ability to retain moisture and repair. Skin scaly index (fine): The cheekbone area was scanned using a VC 20 Plus (Courage & Khazaka, Germany) optical probe, and the SEsc (scaly index) was calculated through reflected light scattering analysis. The higher the value, the more uneven the exfoliation of the stratum corneum and the rougher the skin texture; the lower the value, the more regular the stratum corneum metabolism and the finer and smoother the skin texture.

[0083] The improvement rates for each indicator are calculated as follows: Improvement rate (%) = [(Mean value before use - Mean value after use) / Mean value before use] × 100%; The results are shown in Table 4. Except for the skin cell turnover rate on the arms, the improvement rates presented in Table 4 are all data from follow-up visits after 14 days of continuous use.

[0084] Volunteers used the toner from Application Example 1, Comparison Application Example 1, 11, and the blank application example. The effects on arm skin resurfacing at the initial stage, after 5 days, and after 12 days were as follows: Figure 1As shown, the improvement in facial scaling after volunteers used the toner in Application Example 1 and the blank application example for 14 days is as follows: Figure 2 As shown in the figure, the results indicate that the toner provided in Application Example 1 of the present invention can effectively promote the physiological renewal of the stratum corneum of volunteers' skin and reduce skin scaling.

[0085] As shown in Table 4, the toners provided in Examples 1-9 of this invention all exhibit high rates of keratin renewal, pore improvement, oil control improvement, transepidermal water loss (TEWL) improvement, and scaling improvement. The compositions provided by this invention, based on the combination design of palmitoyl tetrapeptide-10, dipeptide-15, hexanoyl dipeptide-3 (leucine) among peptide components and pomegranate protease, figase, and papain / bromelain among proteases, achieve a dual synergistic mechanism of endogenous regulation of keratin differentiation and physiological desquamation, and exogenous gentle exfoliation of follicular plugs. This effectively promotes physiological keratin renewal, reduces the scaling index, and improves rough skin texture. Simultaneously, it provides good barrier repair, oil control, and pore tightening effects, offering a complete solution for gentle cleansing, oil control, smoothing, and barrier repair of sensitive skin.

[0086] Table 4

[0087] 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 modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A composition for smooth skin and a strong skin barrier suitable for sensitive skin, characterized in that, It includes peptides and proteases in a mass ratio of (0.01-2):(0.1-3); the peptides include palmitoyl tetrapeptide-10, dipeptide-15, and hexanoyl dipeptide-3 leucine in a mass ratio of (1-2):(1-2):(2-4); and the proteases include punicin, figase, and papain-bromelain in a mass ratio of (1-2):(0.1-1):(1-3).

2. The composition according to claim 1, characterized in that, The mass ratio of peptide components to protease components is (0.1-1):(0.5-2).

3. The composition according to claim 1, characterized in that, The mass ratio of peptide components to protease components is (0.3-0.5):(1-1.5).

4. The use of the composition according to any one of claims 1-3 in the preparation of cosmetics.

5. The application as described in claim 4, characterized in that, The cosmetics include toners, lotions, creams, masks, serums, or freeze-dried powders.

6. The application as described in claim 4, characterized in that, The cosmetic product in question is a toner.

7. The application as described in claim 4, characterized in that, The amount of the composition added to the cosmetic product is 1wt%-3wt%.

8. A cosmetic product suitable for sensitive skin that smooths the skin and strengthens the skin barrier, characterized in that, The cosmetic contains the composition according to any one of claims 1-3.

9. A toner, characterized in that, The ingredients comprise the following percentages by weight: 1%-3% of the composition according to any one of claims 1-3, 0.1%-1% of thickener, 2%-15% of humectant, 0.01%-0.3% of pH adjuster, 0.1%-1% of antioxidant, and the balance being deionized water.

10. The lotion as described in claim 9, characterized in that, Includes at least one of the following (a)-(d): (a) The thickener comprises at least one of the following: polyacrylate crosspolymer-6, carbomer, carrageenan, gellan gum, xanthan gum, microcrystalline cellulose, ammonium acryloyl dimethyl taurate / VP copolymer, and acrylate copolymers; (b) The moisturizer comprises at least one of the following: glycerin, butylene glycol, 1,2-hexanediol, 1,3-propanediol, 1,2-pentanediol, panthenol, caprylyl glycol, dipropylene glycol, tremella polysaccharide, trehalose, betaine, allantoin, hyaluronic acid, sodium hyaluronate, acetylated sodium hyaluronate, hydrolyzed sodium hyaluronate, sodium hyaluronate crosspolymer, β-glucan, and ceramide. (c) The pH adjuster is arginine; (d) The antioxidant is p-hydroxyacetophenone.

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