Liquid foundation suitable for sensitive skin and preparation method

Abstract

The invention discloses liquid foundation suitable for sensitive skin and a preparation method, and belongs to the technical field of cosmetics. The invention relates to a liquid foundation suitable for sensitive skin. The liquid foundation comprises an active core component: 3-8% of an aloe barbadensis leaf extract; the base component comprises 45%-60% of A-phase raw materials, 25%-35% of B-phase raw materials and 8%-15% of C-phase raw materials; synergistic soothing and repairing components: 0.5%-1.2% of a purslane extract, 0.3%-0.8% of a crocus sativus flower extract and 0.2%-0.6% of a cardiospermum halicacabum flower and leaf extract; a low-irritation antibacterial auxiliary component: 0.01% to 0.05% of chlorhexidine digluconate; by adopting a synergistic antibacterial system of the aloe barbadensis leaf extract and the low-concentration chlorhexidine digluconate, while the dosage of a synthetic antibacterial agent is reduced, broad-spectrum efficient antibacterial is realized, and the sensitization rate of a human patch test is less than or equal to 0.1%; on the other hand, the plant-derived emulsifier is used for replacing part of the synthetic thickening agent and matched with the relieving and repairing effects of the peptide compound component, so that the overall irritation of the formula is further reduced, and the composition is further suitable for sensitive skin and barrier damaged skin to be used for a long time.

Description

Technical Field

[0001] This invention relates to the field of anti-allergic cosmetics technology, and in particular to a foundation liquid suitable for sensitive skin and its preparation method. Background Technology

[0002] With the segmentation of the beauty consumer market and the increasing skincare awareness of consumers, people with sensitive skin have placed higher demands on the gentleness, safety, and functionality of cosmetics. Foundation, as a core product of base makeup, needs to simultaneously meet the makeup needs of evening skin tone and concealing imperfections, as well as the skincare needs of sensitive skin for "low irritation, barrier repair, and antibacterial protection." However, existing technologies still have certain shortcomings. The contradiction between irritation and efficacy: Sensitive skin has a thin stratum corneum and impaired barrier function, making it prone to adverse reactions such as redness, stinging, and itching when exposed to synthetic preservatives, emulsifiers, and high concentrations of active ingredients. To ensure antibacterial stability, existing foundations often add high concentrations of synthetic antibacterial agents (such as chlorhexidine digluconate at a conventional dosage of 0.1%-0.2%), which, while meeting the requirements for microbial control, significantly increases the risk of sensitization in sensitive skin. On the other hand, simply reducing the amount of functional ingredients can lead to insufficient antibacterial and repairing effects.

[0003] The active ingredients have a single function and poor stability: Most existing foundations for sensitive skin use a single plant extract or active ingredient to achieve single effects such as soothing and moisturizing, lacking a multi-effect synergistic design, making it difficult to solve multiple problems of sensitive skin such as "inflammatory redness, barrier damage, and moisture loss" at the same time. In addition, the active ingredients in plant extracts (such as polysaccharides and flavonoids) are prone to degradation during the heating preparation process of foundation (usually 70-80℃), resulting in a significant reduction in efficacy. Moreover, most extracts can only play a role once in the compounding stage, without fully utilizing their active potential.

[0004] Insufficient Synergistic Effect of Repair Systems: The core needs of sensitive skin are barrier repair and improved tolerance. However, existing products often use simple additives (such as plant extracts and peptides) without forming a targeted synergistic mechanism. For example, some products only add a single repair peptide or plant extract, failing to achieve a progressive effect of "anti-inflammatory-repair-strengthening." Furthermore, plant oils, as key components for moisturizing and repair, lack scientifically designed formulations, making it difficult to simultaneously meet the dual needs of immediate hydration and long-lasting barrier repair.

[0005] Negative impact of manufacturing process on product performance: Current foundation preparation often uses a fixed temperature heating and single rotation speed homogenization process. On the one hand, high temperature can easily damage the structure and efficacy of heat-sensitive active ingredients. On the other hand, a single homogenization parameter can easily lead to uneven product particle size. Rough particles can irritate sensitive skin and affect the penetration and absorption of ingredients, further reducing the effectiveness of repair, moisturizing and other functions. Summary of the Invention

[0006] The purpose of this invention is to solve the problems mentioned in the background art by providing a foundation liquid suitable for sensitive skin and its preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A foundation suitable for sensitive skin, comprising the following components by weight percentage: Active core component: 3%-8% Aloe vera leaf extract, wherein the Aloe vera leaf extract is a standardized extract containing ≥20% aloe polysaccharides; Base components: Phase A raw material 45%-60%, Phase B raw material 25%-35%, Phase C raw material 8%-15%; The A-phase raw material includes at least one of alumina, aluminum distearate, sodium chloride, C77492, lithium dimethyl ammonium stearate montmorillonite, and propylene glycol carbonate; The B-phase raw materials include at least one of the following: sorbitan isostearate, silyl alkylated silica, triethoxyoctylsilane, chlorhexidine digluconate, plantago seed oil, and sunflower seed oil unsaponifiables. The C-phase raw material includes at least one of nicotinamide, tocopheryl acetate, tocopherol, sodium citrate, citric acid, potassium sorbate, and biotin. Synergistic soothing and repairing components: Purslane extract 0.5%-1.2%, Saffron flower extract 0.3%-0.8%, and Rhododendron flower and leaf extract 0.2%-0.6%; Low-irritant antibacterial auxiliary component: chlorhexidine digluconate 0.01%-0.05%, used to form a synergistic antibacterial system with aloe vera leaf extract.

[0008] Preferably, the aloe vera leaf extract is a standardized extract with a concentration of 10%-15%.

[0009] Furthermore, in the synergistic soothing and repairing components, the weight ratio of purslane extract, saffron flower extract, and crape myrtle flower and leaf extract is 1.5:1:0.8.

[0010] Furthermore, the weight ratio of the aloe vera leaf extract to chlorhexidine digluconate is 60-80:1, and the synergistic antibacterial system has an inhibition rate of ≥98% against Staphylococcus aureus and Escherichia coli.

[0011] Furthermore, in the B phase raw material, the weight ratio of unsaponifiable matter of plantain leaf artichoke seed oil to sunflower seed oil is 1:2-3, and the combination of plantain leaf artichoke seed oil and sunflower seed oil unsaponifiable matter forms a dual-effect plant oil system for moisturizing and repairing.

[0012] Furthermore, it also includes 0.1%-0.3% of a peptide complex component, wherein the peptide complex component includes palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and lysine polypeptide, and the weight ratio of palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and arginine / lysine polypeptide is 1:0.8:1.2.

[0013] A method for preparing a foundation suitable for sensitive skin, comprising the following steps: Step 1, Preparation of Phase A: Weigh the Phase A raw material and put it into the main pot, heat it to 70-72℃, and stir until completely dissolved; Step 2, B-phase preparation and emulsification: Mix the B-phase raw materials with the aloe vera leaf extract evenly, add them to the main pot of Step 1, and homogenize and emulsify at 3000 rpm for about 10 minutes. Step 3, Adding Phase C: Cool the materials in the main pot to 45°C, add the Phase C raw materials and synergistic soothing and repairing components one by one, and stir evenly; Step 4, Post-processing: The material is vacuum cooled to 30°C, filtered, and after passing the semi-finished product inspection, it is sequentially canned, tested online, packaged, and tested as a finished product. After passing the inspection, it is put into storage.

[0014] Furthermore, the homogenization emulsification in step two adopts a gradient homogenization process: first homogenize at 2500 rpm for 5 minutes, and then homogenize at 3500 rpm for 5 minutes.

[0015] Furthermore, the C-phase raw material in step three is added by gradient heating: first, the material in the main pot is cooled to 40°C, then a portion of the C-phase raw material is added in batches, and after stirring for 3 minutes, the temperature is raised to 45°C, and the remaining C-phase raw material and synergistic soothing and repairing components are added.

[0016] Furthermore, the foundation liquid has a pH value of 5.5-6.5 and a particle size of ≤10μm.

[0017] Compared with the prior art, the present invention provides a foundation liquid suitable for sensitive skin and a method for its preparation, which has the following beneficial effects: 1. This invention reduces the risk of adverse skin reactions from the root through multiple low-irritation designs: On the one hand, it adopts a synergistic antibacterial system of aloe vera leaf extract and low-concentration chlorhexidine digluconate, which reduces the amount of synthetic antibacterial agents used while achieving broad-spectrum and highly effective antibacterial effects, with a human patch test sensitization rate of ≤0.1%; on the other hand, it replaces some synthetic thickeners with plant-derived emulsifiers, combined with the soothing and repairing effects of peptide compound components, further reducing the overall irritation of the formula, thus making it suitable for long-term use on sensitive skin and skin with damaged barriers.

[0018] 2. This invention selects standardized Aloe vera leaf extract containing ≥20% aloe polysaccharides as the active core component. Its dual mechanism of compound reaction and secondary heating action breaks through the limitations of existing extracts with single-stage and single-effect: In the compounding stage, aloe polysaccharides, flavonoids, base oils, and antibacterial agents work synergistically to achieve barrier repair and auxiliary antibacterial effects; During the heating preparation process, some aloe polysaccharides are slightly hydrolyzed into small molecule polysaccharides, forming a stable moisturizing network with moisturizing ingredients, while the unhydrolyzed residual active ingredients further enhance the repair effect, enabling a single extract to simultaneously perform the triple functions of antibacterial assistance, barrier repair, and long-lasting moisturizing, greatly improving the utilization rate of active ingredients.

[0019] 3. This invention maximizes the repair, moisturizing, and antibacterial effects through a multi-dimensional synergistic system: Synergistic Soothing and Repairing System: Purslane extract, saffron flower extract, and sedum leaf extract are compounded in a specific ratio of 1.5:1:0.8 to form a synergistic effect of anti-inflammatory, antioxidant, and barrier repair. Combined with the progressive repair effects of palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and arginine / lysine peptides, the transdermal water loss rate is reduced by ≥40%, and the stratum corneum moisture content is increased by ≥38%, which is significantly better than single-ingredient or non-specific ratio compounding systems. Moisturizing-Repairing Dual-Effect Oil System: Plantain Leaf and Blue Thistle Seed Oil and Sunflower Seed Oil Unsaponifiables are combined in a 1:2-3 ratio to replenish essential fatty acids and phytosterols for the skin barrier, forming a closed loop of immediate hydration, long-lasting moisture retention and barrier repair, with moisturizing time up to 8 hours or more. Synergistic antibacterial system: Aloe vera leaf extract and chlorhexidine digluconate in a synergistic ratio of 60-80:1 have an inhibition rate of ≥98% against Staphylococcus aureus and Escherichia coli, which not only meets the microbial limit standards for cosmetics, but also avoids the irritation risk of high concentrations of synthetic antibacterial agents.

[0020] 4. In the preparation of this invention, a segmented temperature control and gradient homogenization process design is adopted. On the one hand, the heating temperature of phase A is optimized to 70-72℃, and aloe vera leaf extract is added to phase B to reduce the degradation of heat-sensitive active ingredients and improve the activity retention rate by ≥25%. On the other hand, the gradient homogenization process makes the average particle size of the product ≤10μm, significantly refining the texture and avoiding frictional stimulation of sensitive skin by rough particles, while promoting the penetration and absorption of active ingredients. In addition, the gradient temperature addition method of phase C further ensures the full dissolution and efficacy stability of active ingredients such as peptides and plant extracts, so that the product does not have stratification or precipitation in cold and hot cycling and centrifugation tests, and has excellent stability. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Example 1: A foundation suitable for sensitive skin, comprising the following components: Active core component: 5% Aloe vera leaf extract, which is a standardized extract containing ≥20% aloe polysaccharides; Base components: Phase A raw material, Phase B raw material, Phase C raw material; Phase A raw materials include 2.5% alumina, 1.8% aluminum distearate, 0.3% sodium chloride, 1.2% C77492, 3.5% lithium dimethyl ammonium stearate montmorillonite, and 4.2% propylene glycol carbonate; Phase B ingredients include 2.8% sorbitan isostearate, 3.2% silyl silica, 1.5% triethoxyoctylsilane, 0.07% chlorhexidine digluconate, 3.5% plantain seed oil, and 7% sunflower seed oil unsaponifiables; Phase C raw materials include 2.5% nicotinamide, 1.2% tocopheryl acetate, 0.8% tocopherol, 0.3% sodium citrate, 0.2% citric acid, 0.15% potassium sorbate, and 0.05% biotin. Synergistic soothing and repairing ingredients: Purslane extract 0.9%, Saffron flower extract 0.6%, and Rhododendron flower and leaf extract 0.38%; Low-irritant antibacterial auxiliary component: chlorhexidine digluconate 0.03%, used to form a synergistic antibacterial system with aloe vera leaf extract; It also includes deionized water, which is used to replenish the remaining components.

[0023] Aloe vera leaf extract is a standardized extract with a concentration of 10%-15%.

[0024] In the synergistic soothing and repairing components, the weight ratio of purslane extract, saffron flower extract, and crape myrtle flower and leaf extract is 1.5:1:0.8.

[0025] The weight ratio of aloe vera leaf extract to chlorhexidine digluconate is 60-80:1, and the synergistic antibacterial system has an inhibition rate of ≥98% against Staphylococcus aureus and Escherichia coli.

[0026] In phase B, the weight ratio of unsaponifiable matter from plantain seed oil to sunflower seed oil is 1:2-3. The combination of plantain seed oil and unsaponifiable matter from sunflower seed oil forms a dual-effect plant oil system that moisturizes and repairs.

[0027] It also includes 0.2% of a peptide complex component, which includes palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and lysine polypeptide, with a weight ratio of 1:0.8:1.2.

[0028] A method for preparing a foundation suitable for sensitive skin, comprising the following steps: Step 1, Preparation of Phase A: Weigh the above raw materials for Phase A, put them into the main pot, heat to 71°C, and stir at 500 rpm for 25 minutes until the raw materials are completely dissolved and a uniform Phase A system is formed.

[0029] Step 2, Phase B preparation and emulsification: Mix the raw materials of Phase B with Aloe vera leaf extract evenly to obtain a mixture; slowly add the mixture to the main pot of Step 1 and emulsify using a gradient homogenization process: first homogenize at 2500 rpm for 5 min, then homogenize at 3500 rpm for 5 min to ensure that the system is fully emulsified.

[0030] Step 3, C-phase addition: Cool the emulsified material in the main pot to 40°C, add a portion of the C-phase raw materials (nicotinamide, tocopheryl acetate, tocopherol) in batches, and stir at 400 rpm for 3 minutes; then heat the material to 45°C, add the remaining C-phase raw materials (sodium citrate, citric acid, potassium sorbate, biotin), synergistic soothing and repairing components and peptide compound components, and continue stirring for 15 minutes until evenly mixed.

[0031] Step 4, Post-processing: The material is placed in a vacuum environment of -0.08MPa and cooled to 30℃, then filtered through a 200-mesh filter. The filtered semi-finished product is inspected. After passing the inspection, it is sequentially bottled, and the particle size and pH value of the material are tested online. Then it is packaged. Finally, the finished product is fully tested and stored after passing the test.

[0032] Example 2: A foundation suitable for sensitive skin, comprising the following ingredients: Active core component: 3% Aloe vera leaf extract, which is a standardized extract containing ≥20% aloe polysaccharides; Base components: Phase A raw material, Phase B raw material, Phase C raw material; Phase A raw materials include 2.5% alumina, 1.8% aluminum distearate, 0.3% sodium chloride, 1.2% C77492, 3.5% lithium dimethyl ammonium stearate montmorillonite, and 4.2% propylene glycol carbonate; Phase B ingredients include 2.8% sorbitan isostearate, 3.2% silyl silica, 1.5% triethoxyoctylsilane, 0.07% chlorhexidine digluconate, 3.5% plantain seed oil, and 7% sunflower seed oil unsaponifiables; Phase C raw materials include 2.5% nicotinamide, 1.2% tocopheryl acetate, 0.8% tocopherol, 0.3% sodium citrate, 0.2% citric acid, 0.15% potassium sorbate, and 0.05% biotin. Synergistic soothing and repairing ingredients: Purslane extract 0.9%, Saffron flower extract 0.6%, and Rhododendron flower and leaf extract 0.38%; Low-irritant antibacterial auxiliary component: chlorhexidine digluconate 0.03%, used to form a synergistic antibacterial system with aloe vera leaf extract; It also includes deionized water, which is used to replenish the remaining components.

[0033] Aloe vera leaf extract is a standardized extract with a concentration of 10%-15%.

[0034] In the synergistic soothing and repairing components, the weight ratio of purslane extract, saffron flower extract, and crape myrtle flower and leaf extract is 1.5:1:0.8.

[0035] The weight ratio of aloe vera leaf extract to chlorhexidine digluconate is 60-80:1, and the synergistic antibacterial system has an inhibition rate of ≥98% against Staphylococcus aureus and Escherichia coli.

[0036] In phase B, the weight ratio of unsaponifiable matter from plantain seed oil to sunflower seed oil is 1:2-3. The combination of plantain seed oil and unsaponifiable matter from sunflower seed oil forms a dual-effect plant oil system that moisturizes and repairs.

[0037] It also includes 0.2% of a peptide complex component, which includes palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and lysine polypeptide, with a weight ratio of 1:0.8:1.2.

[0038] A method for preparing a foundation suitable for sensitive skin, comprising the following steps: Step 1, Preparation of Phase A: Weigh the above raw materials for Phase A, put them into the main pot, heat to 71°C, and stir at 500 rpm for 25 minutes until the raw materials are completely dissolved and a uniform Phase A system is formed.

[0039] Step 2, Phase B preparation and emulsification: Mix the raw materials of Phase B with Aloe vera leaf extract evenly to obtain a mixture; slowly add the mixture to the main pot of Step 1 and emulsify using a gradient homogenization process: first homogenize at 2500 rpm for 5 min, then homogenize at 3500 rpm for 5 min to ensure that the system is fully emulsified.

[0040] Step 3, C-phase addition: Cool the emulsified material in the main pot to 40°C, add a portion of the C-phase raw materials (nicotinamide, tocopheryl acetate, tocopherol) in batches, and stir at 400 rpm for 3 minutes; then heat the material to 45°C, add the remaining C-phase raw materials (sodium citrate, citric acid, potassium sorbate, biotin), synergistic soothing and repairing components and peptide compound components, and continue stirring for 15 minutes until evenly mixed.

[0041] Step 4, Post-processing: The material is placed in a vacuum environment of -0.08MPa and cooled to 30℃, then filtered through a 200-mesh filter. The filtered semi-finished product is inspected. After passing the inspection, it is sequentially bottled, and the particle size and pH value of the material are tested online. Then it is packaged. Finally, the finished product is fully tested and stored after passing the test.

[0042] Example 3: A foundation suitable for sensitive skin, comprising the following ingredients: Active core component: 8% Aloe vera leaf extract, which is a standardized extract containing ≥20% aloe polysaccharides; Base components: Phase A raw material, Phase B raw material, Phase C raw material; Phase A raw materials include 2.5% alumina, 1.8% aluminum distearate, 0.3% sodium chloride, 1.2% C77492, 3.5% lithium dimethyl ammonium stearate montmorillonite, and 4.2% propylene glycol carbonate; Phase B ingredients include 2.8% sorbitan isostearate, 3.2% silyl silica, 1.5% triethoxyoctylsilane, 0.07% chlorhexidine digluconate, 3.5% plantain seed oil, and 7% sunflower seed oil unsaponifiables; Phase C raw materials include 2.5% nicotinamide, 1.2% tocopheryl acetate, 0.8% tocopherol, 0.3% sodium citrate, 0.2% citric acid, 0.15% potassium sorbate, and 0.05% biotin. Synergistic soothing and repairing ingredients: Purslane extract 0.9%, Saffron flower extract 0.6%, and Rhododendron flower and leaf extract 0.38%; Low-irritant antibacterial auxiliary component: chlorhexidine digluconate 0.03%, used to form a synergistic antibacterial system with aloe vera leaf extract; It also includes deionized water, which is used to replenish the remaining components.

[0043] Aloe vera leaf extract is a standardized extract with a concentration of 10%-15%.

[0044] In the synergistic soothing and repairing components, the weight ratio of purslane extract, saffron flower extract, and crape myrtle flower and leaf extract is 1.5:1:0.8.

[0045] The weight ratio of aloe vera leaf extract to chlorhexidine digluconate is 60-80:1, and the synergistic antibacterial system has an inhibition rate of ≥98% against Staphylococcus aureus and Escherichia coli.

[0046] In phase B, the weight ratio of unsaponifiable matter from plantain seed oil to sunflower seed oil is 1:2-3. The combination of plantain seed oil and unsaponifiable matter from sunflower seed oil forms a dual-effect plant oil system that moisturizes and repairs.

[0047] It also includes 0.2% of a peptide complex component, which includes palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and lysine polypeptide, with a weight ratio of 1:0.8:1.2.

[0048] A method for preparing a foundation suitable for sensitive skin, comprising the following steps: Step 1, Preparation of Phase A: Weigh the above raw materials for Phase A, put them into the main pot, heat to 71°C, and stir at 500 rpm for 25 minutes until the raw materials are completely dissolved and a uniform Phase A system is formed.

[0049] Step 2, Phase B preparation and emulsification: Mix the raw materials of Phase B with Aloe vera leaf extract evenly to obtain a mixture; slowly add the mixture to the main pot of Step 1 and emulsify using a gradient homogenization process: first homogenize at 2500 rpm for 5 min, then homogenize at 3500 rpm for 5 min to ensure that the system is fully emulsified.

[0050] Step 3, C-phase addition: Cool the emulsified material in the main pot to 40°C, add a portion of the C-phase raw materials (nicotinamide, tocopheryl acetate, tocopherol) in batches, and stir at 400 rpm for 3 minutes; then heat the material to 45°C, add the remaining C-phase raw materials (sodium citrate, citric acid, potassium sorbate, biotin), synergistic soothing and repairing components and peptide compound components, and continue stirring for 15 minutes until evenly mixed.

[0051] Step 4, Post-processing: The material is placed in a vacuum environment of -0.08MPa and cooled to 30℃, then filtered through a 200-mesh filter. The filtered semi-finished product is inspected. After passing the inspection, it is sequentially bottled, and the particle size and pH value of the material are tested online. Then it is packaged. Finally, the finished product is fully tested and stored after passing the test.

[0052] Comparative Example 1: A foundation suitable for sensitive skin is basically the same as in Example 1, except that the aloe vera leaf extract is removed and the amount of deionized water is adjusted accordingly until it reaches 100%. A method for preparing a foundation suitable for sensitive skin is basically the same as in Example 1, except that in step two, when the raw materials of phase B are directly added to the main pot for emulsification, it is not necessary to mix them with aloe vera leaf extract.

[0053] Comparative Example 2: A foundation suitable for sensitive skin is basically the same as that in Example 1, except that the weight ratio of purslane extract, saffron flower extract, and crape myrtle flower and leaf extract in the synergistic soothing and repairing components is 1:1:1, and the specific dosage is 0.62% purslane extract, 0.62% saffron flower extract, and 0.62% crape myrtle flower and leaf extract.

[0054] Comparative Example 3: A foundation suitable for sensitive skin is basically the same as that in Example 1, except that the peptide complex components (palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, arginine / lysine polypeptide) are removed, and the amount of deionized water is adjusted accordingly until it reaches 100%.

[0055] Comparative Example 4: A method for preparing a foundation suitable for sensitive skin is basically the same as in Example 1, except that the homogenization process in step 2 is performed by continuously homogenizing at 3000 rpm for 10 minutes, without using gradient homogenization.

[0056] The foundation liquids prepared in Examples 1, 2, 3 and Comparative Examples 1-4 were tested. The test items and contents are as follows: pH value test: A pH meter was used, and the test was conducted in accordance with GB / T13531.1-2008 "General Test Methods for Cosmetics - Determination of pH Value".

[0057] Particle size test: The particle size of the foundation liquid was measured using a laser particle size analyzer at 25°C, and the average particle size was recorded.

[0058] Sensitization rate test: In accordance with the human patch test method in the "Cosmetic Safety Technical Specifications", 30 volunteers with sensitive skin were selected and used the sample continuously for 28 days. The number of people who experienced adverse reactions such as skin redness, stinging, and itching was counted, and the sensitization rate was calculated.

[0059] Transdermal water loss test: The transdermal water loss tester was used to test the TEWL values ​​of volunteers before using the sample and after 28 days of continuous use, and the TEWL reduction rate was calculated.

[0060] Antibacterial performance test: According to QB / T2738-2012 "Microbiological Test Methods for Cosmetics", the inhibition rate of the sample against Staphylococcus aureus and Escherichia coli was tested.

[0061] Repair performance test: 20 volunteers with damaged skin barrier were selected and used the sample continuously for 28 days. The moisture content of the stratum corneum before and after use was tested and the moisture content improvement rate was calculated.

[0062] The test results are shown in the table below:

[0063] Table 1 Analysis of the data in Table 1 shows that: pH value and particle size: The pH values ​​of Examples 1-3 and each comparative example are all within the sensitive skin adaptation range of 5.5-6.5, which meets the physiological environmental requirements of the skin; the average particle size of Examples 1-3 and Comparative Examples 1-3 is ≤10μm, while the particle size of Comparative Example 4, which uses conventional homogenization process, is 12.5μm, indicating that the gradient homogenization process of the present invention can effectively refine the product particle size and improve skin feel and compatibility; Sensitization rate: The sensitization rate of Examples 1-3 was 0.0%, which was significantly lower than that of the comparative examples. This indicates that the component compound system of the present invention (especially the combination of Aloe vera leaf extract with low-irritant antibacterial components and synergistic soothing and repairing components) can effectively reduce the risk of adverse reactions in sensitive skin and is suitable for the use of sensitive skin. Repair and moisturizing performance: The TEWL reduction rate and stratum corneum moisture content increase rate of Example 1 were significantly higher than those of the comparative examples. The repair and moisturizing effects of the control group without Aloe vera leaf extract were significantly reduced, demonstrating the key role of the dual mechanism of "compound reaction and secondary heating action" of Aloe vera leaf extract in repair and moisturizing performance. The effects of Comparative Example 2 (where the proportion of synergistic soothing and repairing components deviated) and Comparative Example 3 (where the proportion of peptide-free compound components was not as good as those of Example 1) indicate that the specific proportion of synergistic soothing and repairing components and the addition of peptide compound components can further enhance the repair effect. The conventional homogenization process in Comparative Example 4 resulted in slightly inferior repair and moisturizing effects compared to Example 1 due to its larger particle size.

[0064] Antibacterial properties: The antibacterial rates of Examples 1-3 and Comparative Examples 2-4 were all ≥98%, while the antibacterial rate of Comparative Example 1 without Aloe vera leaf extract was only 83.6%-85.3%. This proves that the synergistic antibacterial system formed by Aloe vera leaf extract and chlorhexidine digluconate can significantly improve the antibacterial effect, and low concentration of chlorhexidine digluconate does not increase the risk of sensitization.

[0065] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A foundation suitable for sensitive skin, characterized in that, By weight percentage, it includes the following components: Active core component: 3%-8% Aloe vera leaf extract, wherein the Aloe vera leaf extract is a standardized extract containing ≥20% aloe polysaccharides; Base components: Phase A raw material 45%-60%, Phase B raw material 25%-35%, Phase C raw material 8%-15%; The A-phase raw material includes at least one of alumina, aluminum distearate, sodium chloride, C77492, lithium dimethyl ammonium stearate montmorillonite, and propylene glycol carbonate; The B-phase raw materials include at least one of the following: sorbitan isostearate, silyl alkylated silica, triethoxyoctylsilane, chlorhexidine digluconate, plantago seed oil, and sunflower seed oil unsaponifiables. The C-phase raw material includes at least one of nicotinamide, tocopheryl acetate, tocopherol, sodium citrate, citric acid, potassium sorbate, and biotin. Synergistic soothing and repairing components: Purslane extract 0.5%-1.2%, Saffron flower extract 0.3%-0.8%, and Rhododendron flower and leaf extract 0.2%-0.6%; Low-irritant antibacterial auxiliary component: chlorhexidine digluconate 0.01%-0.05%, used to form a synergistic antibacterial system with aloe vera leaf extract.

2. The foundation liquid suitable for sensitive skin according to claim 1, characterized in that, The aloe vera leaf extract is a standardized extract with a concentration of 10%-15%.

3. A foundation liquid suitable for sensitive skin according to claim 1, characterized in that, In the synergistic soothing and repairing components, the weight ratio of purslane extract, saffron flower extract, and crape myrtle flower and leaf extract is 1.5:1:0.

8.

4. A foundation liquid suitable for sensitive skin according to claim 2, characterized in that, The weight ratio of the aloe vera leaf extract to chlorhexidine digluconate is 60-80:1, and the synergistic antibacterial system has an inhibition rate of ≥98% against Staphylococcus aureus and Escherichia coli.

5. A foundation liquid suitable for sensitive skin according to claim 1, characterized in that, In the B phase raw materials, the weight ratio of unsaponifiable matter of plantain leaf artichoke seed oil to sunflower seed oil is 1:2-3. The combination of plantain leaf artichoke seed oil and sunflower seed oil unsaponifiable matter forms a dual-effect plant oil system for moisturizing and repairing.

6. A foundation liquid suitable for sensitive skin according to claim 1, characterized in that, It also includes 0.1%-0.3% of peptide compound components, wherein the peptide compound components include palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and lysine polypeptide, and the weight ratio of palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and arginine / lysine polypeptide is 1:0.8:1.

2.

7. A method for preparing a foundation liquid suitable for sensitive skin as described in any one of claims 1-6, characterized in that, The steps are as follows: Step 1, Preparation of Phase A: Weigh the Phase A raw material and put it into the main pot, heat it to 70-72℃, and stir until completely dissolved; Step 2, B-phase preparation and emulsification: Mix the B-phase raw materials with the aloe vera leaf extract evenly, add them to the main pot of Step 1, and homogenize and emulsify at 3000 rpm for about 10 minutes. Step 3, Adding Phase C: Cool the materials in the main pot to 45°C, add the Phase C raw materials and synergistic soothing and repairing components one by one, and stir evenly; Step 4, Post-processing: The material is vacuum cooled to 30°C, filtered, and after passing the semi-finished product inspection, it is sequentially canned, tested online, packaged, and tested as a finished product. After passing the inspection, it is put into storage.

8. The method for preparing a foundation for sensitive skin according to claim 7, characterized in that, The homogenization emulsification in step two adopts a gradient homogenization process: first homogenize at 2500 rpm for 5 minutes, and then homogenize at 3500 rpm for 5 minutes.

9. The method for preparing a foundation for sensitive skin according to claim 7, characterized in that, The C-phase raw material in step three is added by gradient heating: first, cool the material in the main pot to 40°C, add some C-phase raw material in batches, stir for 3 minutes, then heat to 45°C, and add the remaining C-phase raw material and synergistic soothing and repairing components.

10. The method for preparing a foundation for sensitive skin according to claim 7, characterized in that, The foundation liquid has a pH value of 5.5-6.5 and a particle size of ≤10μm.

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