Nettle soothing cream and preparation method thereof

Abstract

The nettle soothing cream is prepared from the following raw materials: 1.0 to 3.0 percent of nettle extract, 2.0 to 5.0 percent of aloe extract, 1.5 to 3.5 percent of chamomile extract, 0.5 to 1.5 percent of eucalyptus globulus oil, 0.3 to 1.0 percent of menthol, 10 to 20 percent of oil phase matrix, 40 to 60 percent of carrier solvent, 3.0 to 6.0 percent of surfactant, 1.5 to 3.0 percent of emulsifier, 5.0 to 10 percent of humectant, 0.4 to 0.9 percent of preservative and a pH (Potential of Hydrogen) regulator, olive oil is selected as the oil phase matrix, deionized water is selected as the carrier solvent, alkyl glycoside is selected as the surfactant, lecithin is selected as the emulsifier, glycerin is selected as the humectant, 0.3-0.6% phenoxyethanol and 0.1-0.3% ethylhexylglycerin are selected as the preservatives, and citric acid or sodium lactate is selected as the pH regulator. According to the present invention, the design is reasonable, the rapid analgesia is achieved through the plant anti-inflammatory and physical cold feeling dual-channel according to the post-exercise muscle soreness, skin inflammation (eczema / dermatitis) and sensitive skin relieving requirements, the effects are comprehensive, the mild and non-irritating effects are provided, the permeation effect is good, the environmental protection is achieved, and the important practical significance is provided.

Description

Technical Field

[0001] The present invention relates to the technical field of skin care, and particularly relates to a nettle soothing paste and a preparation method thereof. Background Art

[0002] In the field of skin care, skin inflammation problems such as eczema and dermatitis, as well as the daily care needs of the skin discomfort after exercise and sensitive skin, have received increasing attention.

[0003] Traditional skin care products have many limitations. For example, many skin care products on the market can only meet a single efficacy, such as simple moisturizing or itching relief, and it is difficult to achieve multiple functions such as anti-inflammatory, antibacterial, anti-allergic, soothing, moisturizing, and cleaning at the same time, and cannot effectively deal with complex skin problems. And some products use strong irritating surfactants, preservatives and other ingredients in pursuit of cleaning power or stability. These ingredients are easy to damage the skin barrier, resulting in skin sensitivity, dryness, flushing and other problems. Especially for people with sensitive skin, using them will not only not improve the skin condition, but will aggravate the discomfort. Therefore, we designed a nettle soothing paste and a preparation method thereof. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art, and to provide a nettle soothing paste and a preparation method thereof. It aims at the needs of muscle soreness after exercise, skin inflammation (eczema / dermatitis), and sensitive skin soothing. It realizes rapid analgesia through the dual channels of plant anti-inflammatory + physical cold feeling, has comprehensive efficacy, is mild and non-irritating, has good penetration effect and is environmentally friendly, and has important practical significance.

[0005] In order to achieve the above purpose, the present invention adopts the following technical scheme: A nettle soothing paste, the nettle soothing paste comprises the following raw materials: 1.0 - 3.0% of nettle extract, 2.0 - 5.0% of aloe extract, 1.5 - 3.5% of chamomile extract, 0.5 - 1.5% of eucalyptus oil, 0.3 - 1.0% of menthol, 10 - 20% of oil phase matrix, 40 - 60% of carrier solvent, 3.0 - 6.0% of surfactant, 1.5 - 3.0% of emulsifier, 5.0 - 10% of humectant, 0.4 - 0.9% of preservative, pH regulator; The flavonoid content in the nettle extract is ≥1.0%, the polysaccharide content in the aloe extract is ≥2.0%, and the chamazulene content in the chamomile extract is ≥1.5%; The oil-phase matrix is selected as olive oil, the carrier solvent is selected as deionized water, the surfactant is selected as alkyl glucoside, the emulsifier is selected as lecithin, the humectant is selected as glycerol, the preservative is selected as 0.3 - 0.6% phenoxyethanol and 0.1 - 0.3% ethylhexylglycerol, and the pH regulator is used to adjust the pH of the paste to 5.5 - 6.5. The pH regulator is selected from citric acid or sodium lactate.

[0006] Preferably, the nettle extract is prepared by low-temperature extraction or supercritical fluid extraction to ensure the retention of the active ingredients of nettle.

[0007] A preparation method of a nettle soothing paste comprises the following steps: S1. Raw material pretreatment: Preparation of nettle extract (low-temperature extraction): After crushing the dried nettle leaves, an appropriate amount of ethanol-water mixed solvent is added, and extraction is carried out at 40 - 50 °C for 2 - 3 times, 1 - 2 hours each time. The extraction solutions are filtered and combined, and the solvent is removed by vacuum distillation to obtain a concentrated nettle extract solution for standby; Preparation of aloe extract: Select fresh aloe, take the gel part after peeling, crush it into a homogeneous paste, then filter to remove impurities to obtain the original aloe gel solution, and perform pasteurization to obtain the aloe extract, which is cooled and reserved for use; Preparation of chamomile extract: Crush the dried chamomile flower petals, and extract chamomile essential oil by steam distillation for standby; Treatment of eucalyptus oil and menthol: Food-grade eucalyptus oil and menthol crystals are selected, and menthol is pre-dissolved in propylene glycol to form a liquid state; S2. Preparation of the paste by phase separation emulsification method: Preparation of the oil phase: The nettle extract is encapsulated in a lecithin - arabic gum composite wall material by spray drying to form microcapsules with a particle size ≤ 50 μm. In a clean container, the microencapsulated nettle extract, eucalyptus oil, olive oil, menthol, and a part of the emulsifier lecithin are added in sequence, heated to 70 - 80 °C, and stirred evenly to fully dissolve each component to form a uniform oil phase; Preparation of the water phase: In another container, add deionized water, aloe extract, chamomile extract, the surfactant alkyl glucoside, the humectant glycerol, and the remaining emulsifier lecithin, heat to 70 - 80 °C, and stir evenly to prepare the water phase; Emulsification: Under high-speed stirring at 300 - 500 revolutions per minute, the water phase is slowly added to the oil phase. Emulsification stage: High-speed stirring at 300 - 500 revolutions per minute for 30 - 40 minutes to fully emulsify the oil phase and the water phase to form a stable paste matrix. Homogenization stage: The stirring speed is reduced to 100 - 200 revolutions per minute to maintain the stability of the system and ensure uniform emulsification; S3. Cooling and adding preservatives: When the temperature of the emulsified paste drops to 35 - 40 °C, add the pre-dissolved preservatives and pH regulators, continue stirring for 10 - 15 minutes, then let it stand to defoam, so that the preservatives are evenly dispersed in the paste; S4. Filling and packaging: After cooling the prepared nettle soothing paste to room temperature, fill it into the pre-prepared environmentally friendly packaging containers through a sterile filling device, then seal and package it, and attach a product label indicating the product name, ingredients, usage method, and shelf life.

[0008] Preferably, in step S1, after the raw materials are pretreated, the contents of the active ingredients of nettle extract, aloe vera, and chamomile are detected by high performance liquid chromatography (HPLC) to ensure that the nettle extract is ≥1%.

[0009] Preferably, in step S4, use a pH meter to measure the pH value of the finished product before filling to ensure that it is within the range of 5.5 - 6.5.

[0010] Preferably, in step S4, place the product under different temperature and humidity conditions for accelerated stability test and long-term stability test, and observe whether there are changes in the appearance, texture, and smell of the product to ensure the stability of the product within the shelf life.

[0011] Preferably, in step S3, the final particle size of the paste should be ≤50 μm to ensure the transdermal absorption rate.

[0012] Preferably, select multiple volunteers for the product for multiple skin patch tests to observe whether there are irritating reactions such as erythema, itching, and swelling to ensure that the product is mild and non-irritating.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This nettle soothing paste is mainly composed of nettle extract, supplemented with natural ingredients such as aloe vera and chamomile, achieving the synergistic effect of multiple functions such as anti-inflammatory, antibacterial, anti-allergic, soothing, moisturizing, and cleansing. The mild surfactant ensures the cleaning power without damaging the skin barrier. Menthol can bring a cool feeling, quickly relieve the burning and fatigue of the skin after exercise, and is close to the natural pH value of the skin, meeting the diverse skin care needs of different people.

[0014] 2. This nettle soothing paste uses eucalyptus oil as a penetration enhancer, which can promote the penetration of effective ingredients such as nettle extract into the deep layer of the skin, enabling the active ingredients to play a better role and enhancing the overall efficacy of the product. It is designed with a refreshing paste texture, easy to apply and absorb, does not bring a greasy feeling to the skin, and uses degradable materials for packaging, reducing the impact on the environment. Description of the Drawings

[0015] Figure 1Schematic diagram of the components of a nettle soothing cream proposed by the present invention; Figure 2 Flow chart of the preparation method of a nettle soothing cream proposed by the present invention. Specific embodiments

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0017] A nettle soothing cream, the nettle soothing cream includes the following raw materials: nettle extract 1.0 - 3.0%, aloe extract 2.0 - 5.0%, chamomile extract 1.5 - 3.5%, eucalyptus oil 0.5 - 1.5%, menthol 0.3 - 1.0%, oil phase matrix 10 - 20%, carrier solvent 40 - 60%, surfactant 3.0 - 6.0%, emulsifier 1.5 - 3.0%, moisturizer 5.0 - 10%, preservative 0.4 - 0.9%, pH regulator; The flavonoid content in the nettle extract is ≥1.0%, the polysaccharide content in the aloe extract is ≥2.0%, and the chamazulene content in the chamomile extract is ≥1.5%; The nettle extract is extracted by low - temperature extraction or supercritical fluid extraction to ensure the retention of nettle active ingredients.

[0018] Among them, the nettle extract, as the core ingredient, contains flavonoids (such as quercetin) that can inhibit the COX - 2 pathway, reduce the PGE2 inflammatory factor, and has anti - inflammatory, antibacterial, and anti - allergic effects; The aloe extract has the effects of moisturizing and repairing the skin barrier, and can relieve dryness and discomfort; The chamomile extract is rich in various active ingredients, has anti - inflammatory, anti - allergic, and sedative effects, and synergizes with the nettle extract to enhance the soothing effect on sensitive skin and relieve itching; Eucalyptus oil, as a penetration enhancer, can promote the penetration of effective ingredients such as nettle extract into the deep layer of the skin and enhance the effect; Menthol can provide an instantaneous cold sensation, relieve the burning sensation after exercise, and at the same time has a certain cooling and itching - relieving effect.

[0019] The oil phase matrix is selected as olive oil. As the basis of the oil phase, olive oil can moisten the skin and enhance the stability of the paste. The carrier solvent is selected as deionized water. As the water phase solvent, deionized water can adjust the texture of the paste and dilute the components. The surfactant is selected as alkyl polyglycoside, which can gently clean and does not damage the skin barrier while ensuring the cleaning power. The emulsifier is selected as lecithin. Lecithin is a natural emulsifier that can stabilize the oil-water phase system. The humectant is selected as glycerol, which can increase the water content of the skin, enhance the moisturizing effect of the product, and keep the skin moist. The preservative is selected as 0.3 - 0.6% phenoxyethanol and 0.1 - 0.3% ethylhexylglycerin. Phenoxyethanol is a mild preservative to prevent microbial contamination. Ethylhexylglycerin synergistically preserves, reduces irritation, and enhances safety. The pH regulator is used to adjust the pH of the paste to 5.5 - 6.5. The pH regulator is selected as citric acid or sodium lactate. Adjusting the pH of the paste to 5.5 - 6.5 is compatible with the natural weakly acidic environment of the skin and can reduce the irritation to sensitive skin.

[0020] In this raw material ratio, the nettle extract is used as the core ingredient, and the minimum concentration is set at 1% to ensure the anti-inflammatory effect. Aloe vera and chamomile are slightly higher than nettle to play a strengthening synergistic role. The ratio of 10% - 20% oil phase to 40% - 60% water phase takes into account both moisturizing and refreshing feelings. The cooperation of 1.5% - 3.0% emulsifier and 3.0% - 6.0% surfactant can ensure the stability and cleaning power of the paste. The total content of the preservative is controlled within 1%, and a mild and low-toxic compound system is preferably selected, which can reduce the dependence on chemical additives by adjusting the component ratio and meets the usage requirements of sensitive skin.

[0021] The present invention also discloses a preparation method of the nettle soothing paste, which includes the following steps: S1. Pretreatment of raw materials: Preparation of nettle extract (low-temperature extraction): After crushing the dried nettle leaves to 60 meshes, add an appropriate amount of ethanol-water mixed solvent, such as the volume fraction of ethanol is 50% - 70%. Under the conditions of 40 - 50 °C, extract 2 - 3 times, 1 - 2 hours each time. Filter and combine the extractive solutions, and remove the solvent by vacuum distillation to obtain the concentrated nettle extract solution for standby.

[0022] If the supercritical fluid extraction method is adopted, carbon dioxide is used as the extractant, the extraction pressure is 20 - 30 MPa, the extraction temperature is 35 - 45 °C, and the extraction time is 1 - 2 hours to obtain a high-purity nettle flavonoid extract, which is concentrated and then used for standby.

[0023] Preparation of aloe vera extract: Select fresh aloe vera, remove the skin and take the gel part, stir it into a homogenate, then filter to remove impurities to obtain the original aloe vera gel solution, perform pasteurization to obtain the aloe vera extract, and cool it for standby.

[0024] Preparation of chamomile extract: Crush the dried chamomile flower petals, and extract chamomile essential oil by steam distillation method, or extract with ethanol with a volume fraction of 70% at 50 °C for 2 times, 1 hour each time. After combining the extraction solutions, concentrate by vacuum distillation to obtain chamomile extract for standby.

[0025] After the raw materials are pretreated, use high performance liquid chromatography (HPLC) to detect the contents of active ingredients in nettle extract, aloe vera, and chamomile, and ensure that the nettle extract ≥ 1%.

[0026] Treatment of eucalyptus oil and menthol: Select food-grade eucalyptus oil and menthol crystals. Menthol is pre-dissolved in propylene glycol to form a liquid state.

[0027] S2. Preparation of paste by phase separation emulsification method: Preparation of oil phase: Use spray drying method to encapsulate nettle extract in lecithin-gum arabic composite wall material to form microcapsules with a particle size ≤ 50 μm. Microencapsulation technology can isolate water-oil incompatible components. Through the affinity of the wall material (lecithin) with the oil phase and the affinity of the core material (nettle extract) with the water phase, stable encapsulation is achieved. In a clean container, sequentially add microencapsulated nettle extract, eucalyptus oil, olive oil, menthol, and part of the emulsifier lecithin, heat to 70 - 80 °C, stir evenly to fully dissolve each component, and form a uniform oil phase; Preparation of water phase: In another container, add deionized water, aloe vera extract, chamomile extract, surfactant alkyl glycoside, humectant glycerol, and the remaining emulsifier lecithin, heat to 70 - 80 °C, stir evenly to make a water phase; Emulsification: Under high-speed stirring at 300 - 500 revolutions per minute, slowly add the water phase to the oil phase. Emulsification stage: Stir at 300 - 500 revolutions per minute for 30 - 40 minutes to fully emulsify the oil phase and the water phase to form a stable paste matrix. Homogenization stage: Reduce the stirring speed to 100 - 200 revolutions per minute to maintain the stability of the system and ensure uniform emulsification.

[0028] S3. Cooling and adding preservatives: When the temperature of the emulsified paste drops to 35 - 40 °C, add the pre-dissolved preservatives and pH regulators, continue to stir for 10 - 15 minutes, and then let it stand to defoam, so that the preservatives are evenly dispersed in the paste. Detect by laser particle size analyzer, and the final particle size of the paste should be ≤ 50 μm to ensure the transdermal absorption rate.

[0029] S4. Filling and Packaging: Before filling, use a pH meter to measure the pH value of the finished product to ensure it is within the range of 5.5 - 6.5. If it does not meet the standard, adjust it with citric acid or sodium lactate. After cooling the prepared nettle soothing cream to room temperature, fill it into pre-prepared environmentally friendly packaging containers through a sterile filling device. The filling temperature should be ≤30°C to avoid the volatilization of menthol. The packaging containers can be degradable plastic bottles or glass bottles. Then, carry out sealed packaging, affix product labels, and indicate information such as product name, ingredients, usage method, shelf life, etc.

[0030] Place the product at different temperatures such as 45°C - 50°C and different humidity conditions for accelerated stability tests and long-term stability tests, and observe whether there are changes in the appearance, texture, and smell of the product to ensure the stability of the product within the shelf life.

[0031] Select multiple volunteers, such as 20 - 30 people, for multiple skin patch tests, and observe whether there are irritating reactions such as erythema, itching, and swelling to ensure that the product is mild and non-irritating. Only products that pass all quality inspections can be put on the market for sale.

[0032] The present invention can be further illustrated by the following specific embodiments: Taking the preparation of 100g of the finished product in the laboratory as an example, carry out the preparation and performance verification of the nettle soothing cream: S1. Raw Material Pretreatment Preparation of nettle extract: Weigh a certain amount of dried nettle leaves, crush them and add an appropriate amount of ethanol - water mixed solvent with an ethanol volume fraction of 5 - 70%. Taking 50g of nettle leaves as an example, add the solvent according to the solid - liquid ratio of 1:10 (g / mL), and extract at 40 - 50°C for 2 - 3 times, 1 - 2 hours each time. Filter and combine the extraction liquid, and remove the solvent by vacuum distillation to obtain the concentrated nettle extract for standby.

[0033] Treatment of aloe vera: Select fresh aloe vera, take about 20g of the gel part after peeling, crush it into a homogeneous slurry, and then filter to remove impurities to obtain aloe vera extract for standby.

[0034] Treatment of chamomile: Weigh 10g of dried chamomile petals and crush them. Extract chamomile essential oil by steam distillation method or extract chamomile extract by ethanol extraction method, and concentrate it after extraction for standby.

[0035] S2. Preparation Process Preparation of the oil phase: Use the spray drying method to encapsulate 1g of nettle extract in a lecithin - arabic gum composite wall material to form microcapsules with a particle size ≤50μm. In a clean container, add the microencapsulated nettle extract, 3g of eucalyptus oil, 20g of olive oil, 2g of menthol, and 2g of lecithin (as an emulsifier), heat to 70 - 80°C, and stir evenly to fully dissolve each component to form a uniform oil phase.

[0036] Aqueous phase preparation: In another container, add 60 g of deionized water, 5 g of aloe vera gel juice, 3 g of chamomile extract, 5 g of alkyl polyglycoside, 10 g of glycerol, and the remaining 1 g of lecithin. Heat to 70 - 80°C and stir evenly to prepare the aqueous phase.

[0037] Emulsification: Under stirring conditions, slowly add the aqueous phase to the oil phase. Emulsification stage: Stir at a high speed of 300 - 500 revolutions per minute for 30 - 40 minutes to fully emulsify the oil phase and the aqueous phase to form a stable paste matrix. Homogenization stage: Reduce the stirring speed to 100 - 200 revolutions per minute to maintain the stability of the system, ensure uniform emulsification, fully emulsify the oil phase and the aqueous phase, and form a stable paste matrix.

[0038] Cooling and adding preservatives: When the temperature of the emulsified paste drops to 40 - 50°C, add the pre-dissolved preservatives of phenoxyethanol and ethylhexylglycerin (total amount about 0.5 - 1 g), and continue to stir for 10 - 15 minutes to evenly disperse the preservatives in the paste.

[0039] Use a precision pH meter to detect the pH value of the prepared nettle soothing paste to ensure it is within the range of 5.5 - 6.5. If the pH value does not meet the requirements, it can be adjusted by adding an appropriate amount of citric acid or sodium hydroxide solution.

[0040] S3. Filling and packaging: After cooling the prepared nettle soothing paste to room temperature, fill it into the pre-prepared environmentally friendly packaging containers, such as degradable plastic bottles or glass bottles, through a sterile filling device, then carry out sealed packaging, and affix product labels indicating product name, ingredients, usage method, shelf life and other information.

[0041] Laboratory test data 1. Quantitative analysis of active ingredients Detect 10 batches of finished products by high performance liquid chromatography (HPLC), and the results show:

[0042] The content of active ingredients in all batches of products meets the design standards, and the difference between batches is controlled within a very small range (CV value < 7%) to ensure the stability of efficacy.

[0043] 2. Detection of microbial indicators Detect 10 batches of products according to the "Technical Specifications for Cosmetics Safety":

[0044] All samples do not show excessive microorganisms and meet the requirements for safe use.

[0045] The anti-inflammatory, moisturizing, and cooling effects of the nettle soothing cream are verified through in vitro experiments, human trials, and consumer feedback, combined with specific data, and a comparative analysis is conducted with traditional products as follows: I. Verification of anti-inflammatory effect in in vitro experiments Experimental design: Model: Human keratinocyte (HaCaT) inflammation model, and lipopolysaccharide (LPS) is used to induce the inflammatory response.

[0046] Grouping: Blank group: Untreated cells. Inflammatory model group: Stimulated with LPS, untreated. Experimental group: Stimulated with LPS + nettle soothing cream (1 mg / cm²). Positive control group: Stimulated with LPS + 1% diclofenac (traditional anti-inflammatory drug).

[0047] Detection index: The concentration of prostaglandin E2 (PGE2) is measured by ELISA method.

[0048] Data results:

[0049] From the above experimental data, it can be seen that the nettle soothing cream significantly inhibits the generation of the inflammatory factor PGE2 (inhibition rate 42.3%). Although it is weaker than diclofenac, it has no cytotoxicity (the cell survival rate detected by the MTT method > 95%), and the safety is higher.

[0050] II. Human trials 1. Verification of moisturizing and barrier repair effects Experimental design: Subjects: 30 volunteers with sensitive skin (female, 25 - 45 years old), divided into two groups: experimental group (using the nettle soothing cream 2 times a day for 4 weeks) and control group (using a basic moisturizing cream (containing 5% glycerol, without plant extracts)).

[0051] Detection methods: Skin water content: Measured by Corneometer CM825 (AU value); Transepidermal water loss (TEWL): Detected by Tewameter TM300 (g / m² / h).

[0052] Data results:

[0053] From the above experimental data, it can be seen that the skin water content in the experimental group increased by 72% (from 22.5 AU to 38.7 AU), which was significantly higher than that in the control group (increased by 31%), confirming the synergistic moisturizing effect. And the TEWL value decreased by 34%, indicating an enhanced skin barrier function.

[0054] 2. Cooling effect and analgesia after exercise Experimental design: Subjects: 50 fitness enthusiasts (VAS score of quadriceps soreness after exercise ≥ 6 points).

[0055] Method: Immediately apply nettle soothing paste after exercise and record: Duration of cold sensation: Monitor skin temperature changes with an infrared thermal imager (FLIR T540). Analgesic effect: VAS pain score (0 - 10 points) and muscle hardness (detected by MyotonPRO).

[0056] Data results:

[0057] From the above experimental data, it can be seen that the skin temperature drops by 4.2 °C within 5 minutes, the cold sensation intensity reaches level 3 of the ISO 13732 - 1 standard (obvious cold sensation), and it can quickly relieve pain. Moreover, after 30 minutes, the pain score decreases by 53% and the muscle hardness decreases by 15%, which is better than traditional cold compress patches (only reducing the pain score by 30%), and has a continuous analgesic effect.

[0058] 3. Skin irritation test Conduct a 48 - hour closed patch test on 100 volunteers.

[0059] Data results:

[0060] The incidence of irritation in the experimental group has no significant difference from that in the normal saline group (p > 0.05), which confirms the mildness of the product.

[0061] 4. Comparison with traditional salicylic acid products Data results:

[0062] From the above experimental data, it can be seen that this nettle soothing paste combines physical cooling and plant anti - inflammation synergistically, with a faster onset. It has no risk of peeling, is suitable for long - term use, and is environmentally friendly.

[0063] III. Consumer feedback Consumer satisfaction survey (≥ 200 people): Cold sensation effect: 89% of users think that "the cold sensation is obvious and persistent"; Anti - inflammatory and soothing: 78% of users feedback that "the speed of swelling reduction is accelerated"; Texture preference: 92% of users recognize that "it is refreshing and non - sticky"; Odor acceptance: 91.2% of users feedback that "it has a natural plant fragrance and no pungent smell"; Willingness to repurchase: 82.6% of users said that "they will use it for a long time and it is suitable for sensitive skin".

[0064] Verified through three-fold validation of cell experiments, human efficacy tests, and consumer research, the core effects of this Nettle Soothing Balm are fully supported: 1. Anti-inflammatory: Inhibits PGE2 by 42.3% and targets and blocks the NF-κB pathway.

[0065] 2. Moisturizing: Increases skin water content by 72% and repairs the barrier.

[0066] 3. Cooling sensation: Reduces temperature by 4.2°C in 5 minutes and lasts for over 30 minutes.

[0067] 4. Safe and environmentally friendly: Zero irritation, zero peeling, and the degradation rate of PLA packaging ≥ 90%.

[0068] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A nettle soothing paste, characterized in that, The nettle soothing paste comprises the following raw materials: 1.0 - 3.0% of nettle extract, 2.0 - 5.0% of aloe extract, 1.5 - 3.5% of chamomile extract, 0.5 - 1.5% of eucalyptus oil, 0.3 - 1.0% of menthol, 10 - 20% of oil phase matrix, 40 - 60% of carrier solvent, 3.0 - 6.0% of surfactant, 1.5 - 3.0% of emulsifier, 5.0 - 10% of humectant, 0.4 - 0.9% of preservative, and pH regulator; The flavonoid content in the nettle extract is ≥1.0%, the polysaccharide content in the aloe extract is ≥2.0%, and the chamazulene content in the chamomile extract is ≥1.5%; The oil phase matrix is selected as olive oil, the carrier solvent is selected as deionized water, the surfactant is selected as alkyl glycoside, the emulsifier is selected as lecithin, the humectant is selected as glycerol, the preservative is selected as 0.3 - 0.6% of phenoxyethanol and 0.1 - 0.3% of ethylhexylglycerin, the pH regulator is used to adjust the pH of the paste to 5.5 - 6.5, and the pH regulator is selected as citric acid or sodium lactate.

2. The nettle soothing paste according to claim 1, characterized in that, The nettle extract is prepared by low-temperature extraction or supercritical fluid extraction to ensure the retention of nettle active ingredients.

3. A method for preparing a nettle soothing paste, which is used to prepare the nettle soothing paste described in claim 1, and is characterized in that, It includes the following steps: S1. Raw material pretreatment: Preparation of nettle extract (low-temperature extraction): After drying and crushing nettle leaves, add an appropriate amount of ethanol-water mixed solvent, and extract at 40 - 50°C for 2 - 3 times, 1 - 2 hours each time. Filter and combine the extraction solutions, and remove the solvent by vacuum distillation to obtain the concentrated nettle extract solution for standby; Preparation of aloe extract: Select fresh aloe, remove the skin and take the gel part, crush it into a homogeneous pulp, then filter to remove impurities to obtain the original aloe gel solution, perform pasteurization to obtain the aloe extract, and cool for standby; Preparation of chamomile extract: Crush the dried chamomile flower petals and extract chamomile essential oil by steam distillation for standby; Treatment of eucalyptus oil and menthol: Select food-grade eucalyptus oil and menthol crystals, and dissolve menthol in propylene glycol in advance to form a liquid state; S2. Preparation of the paste by phase separation emulsification method: Preparation of the oil phase: Wrap the nettle extract in a lecithin - arabic gum composite wall material by spray drying to form microcapsules with a particle size ≤50μm. In a clean container, sequentially add the microencapsulated nettle extract, eucalyptus oil, olive oil, menthol, and part of the emulsifier lecithin, heat to 70 - 80°C, stir evenly to fully dissolve each component to form a uniform oil phase; Preparation of the water phase: In another container, add deionized water, aloe extract, chamomile extract, surfactant alkyl glycoside, humectant glycerol, and the remaining emulsifier lecithin, heat to 70 - 80°C, stir evenly to prepare the water phase; Emulsification: Under high-speed stirring at 300 - 500 revolutions per minute, slowly add the water phase to the oil phase. Emulsification stage: Stir at 300 - 500 revolutions per minute for 30 - 40 minutes to fully emulsify the oil phase and the water phase to form a stable paste matrix. Homogenization stage: Reduce the stirring speed to 100 - 200 revolutions per minute to maintain the stability of the system and ensure uniform emulsification; S3. Cooling and adding preservatives: When the temperature of the emulsified paste drops to 35 - 40 °C, add the pre-dissolved preservatives and pH regulators, continue stirring for 10 - 15 minutes, and then let it stand to defoam, so that the preservatives are evenly dispersed in the paste. S4. Filling and packaging: After cooling the prepared nettle soothing paste to room temperature, fill it into the pre-prepared environmentally friendly packaging containers through a sterile filling device, then seal and package it, and affix a product label indicating the product name, ingredients, usage method, and shelf life.

4. The preparation method of a nettle soothing paste according to claim 3, characterized in that, In S1, after the raw materials are pretreated, the contents of the active ingredients of nettle extract, aloe vera, and chamomile are detected by high performance liquid chromatography (HPLC) to ensure that the nettle extract is ≥ 1%.

5. The preparation method of a nettle soothing paste according to claim 3, characterized in that, In S4, use a pH meter to measure the pH value of the finished product before filling to ensure that it is within the range of 5.5 - 6.

5.

6. The preparation method of a nettle soothing paste according to claim 3, characterized in that In S4, place the product under different temperature and humidity conditions for accelerated stability tests and long-term stability tests, and observe whether the appearance, texture, and odor of the product change to ensure the stability of the product during the shelf life.

7. The preparation method of a nettle soothing paste according to claim 3, characterized in that, In S3, the final particle size of the paste should be ≤ 50 μm to ensure the transdermal absorption rate.

8. The preparation method of a nettle soothing paste according to claim 3, characterized in that Select multiple volunteers for the product and conduct multiple skin patch tests to observe whether there are erythema, itching, and swelling irritation reactions to ensure that the product is mild and non-irritating.

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