A plant-based mosquito repellent composition and method of making the same

Abstract

This invention relates to the field of mosquito repellent composition technology, specifically to a plant-based mosquito repellent composition and its preparation method, comprising Sophora flavescens extract, eucalyptol, montmorillonite glycol, and natural Echinacea purpurea extract; the natural Echinacea purpurea extract is an aqueous extract with a chicoric acid content ≥4%. The plant-based mosquito repellent composition and preparation method of this invention, through functional optimization of single components and synergistic formulation of multiple components, fundamentally solves the core problems of existing plant-based mosquito repellent products, such as poor mosquito repellent effect, short effective duration, and lack of skin soothing function, while also taking into account the product's naturalness and safety. Because a combined low-temperature enzymatic hydrolysis-stepwise alcohol extraction-microfiltration purification process is used to prepare the Sophora flavescens extract, and natural menthol extract is added as a drug guide, the extraction rate and utilization efficiency of plant active ingredients are effectively improved, reducing the waste of plant resources. Furthermore, the preparation process is green and environmentally friendly, generating no harmful waste.

Description

Technical Field

[0001] This invention relates to the field of mosquito repellent composition technology, specifically to a plant-based mosquito repellent composition and its preparation method. Background Technology

[0002] Mosquito bites not only cause direct skin discomfort such as itching and redness, but can also transmit various infectious diseases such as dengue fever, malaria, and Japanese encephalitis. Therefore, mosquito repellent products have important applications in daily life, outdoor work, and epidemic prevention. Currently, mosquito repellent products on the market are mainly divided into two categories: chemically synthesized and plant-based. Chemically synthesized mosquito repellent products use DEET and IR3535 as core ingredients, which have significant mosquito-repelling effects but can be irritating. Long-term use may damage the skin, and they are especially unsuitable for infants, people with sensitive skin, and pregnant women. In addition, some chemical mosquito repellent ingredients can also cause environmental pollution. Plant-based mosquito repellent products are gradually becoming the market trend due to their high safety and gentle, non-irritating characteristics. However, they generally have weaker mosquito-repelling effects and shorter effective duration. At the same time, most plant-based mosquito repellent formulas only focus on repellency and lack the function of soothing and repairing the skin after mosquito bites, making it difficult to meet the actual needs of consumers.

[0003] Based on this, developing a plant-based mosquito repellent composition with a natural formula, significant mosquito repellent effect, skin soothing and anti-inflammatory function, flexible dosage form, and gentle preparation process has become a key direction for solving the problems of existing plant-based mosquito repellent products, and also meets the current market demand of consumers for green, safe, and efficient mosquito repellent products. Summary of the Invention

[0004] The purpose of this invention is to provide a plant-based mosquito repellent composition and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A plant-based mosquito repellent composition, by weight, comprises 0.1-5 parts of Sophora flavescens extract, 5-15 parts of eucalyptol, 5-20 parts of menthol, and 0.02-0.1 parts of natural purple coneflower extract; wherein the natural purple coneflower extract is an aqueous extract with a chicoric acid content ≥4%, which works synergistically with Sophora flavescens extract, eucalyptol, and menthol to delay the volatilization rate of eucalyptol and menthol, improve the skin compatibility of the composition, and enhance the effect of Sophora flavescens extract in eliminating mosquito-attracting substances from the human body.

[0006] As a further technical solution, the Sophora flavescens extract is prepared by a combined process of low-temperature enzymatic hydrolysis-stepwise alcohol extraction-microfiltration purification, with natural menthol extract added as a drug guide during the preparation process; the natural menthol extract is a cold extract of peppermint stems and leaves, with a menthol content ≥98%, which promotes the transdermal absorption of matrine and sophoridine in the Sophora flavescens extract and enhances the efficiency of the Sophora flavescens extract in clearing mosquito-attracting substances from the human body; the preparation of the Sophora flavescens extract does not involve a high-temperature treatment step, thus retaining the alkaloid active ingredients in Sophora flavescens.

[0007] As a further technical solution, the preparation method of the Sophora flavescens extract includes the following steps: Take Sophora flavescens root powder, crush it and pass it through a 40-60 mesh sieve. Add 3-5 times the weight of purified water to Sophora flavescens root powder, then add 2%-3% of the weight of Sophora flavescens root powder compound enzyme and 1.2%-1.5% of the weight of Sophora flavescens root powder natural menthol extract. Under constant temperature stirring conditions of 35-40℃ and 80-100 r / min, enzymatic hydrolyze for 1-2 hours to obtain Sophora flavescens enzymatic hydrolysate. The compound enzyme is a mixture of pectinase and cellulase with an enzyme activity ratio of 2:1. Add 2-3 times the volume of 30% food-grade ethanol to the Sophora flavescens enzymatic hydrolysate, and extract at room temperature for 2 hours at 25-28℃ in the dark. Filter to obtain the first extract. Add 2-3 times the volume of 60% food-grade ethanol to the filter residue, and extract at room temperature for 2 hours at 25-28℃ in the dark. Filter to obtain the second extract. The primary and secondary extracts were combined and concentrated under reduced pressure at a vacuum of -0.08 to -0.10 MPa and a temperature of 40 to 45°C to 1 / 5 to 1 / 4 of the original total volume of the extract, to obtain a concentrated Sophora flavescens extract. The concentrated Sophora flavescens extract was purified and filtered through a 0.45μm ceramic microfiltration membrane to remove insoluble impurities, and then concentrated to a solid content of 10%~20% to obtain Sophora flavescens extract.

[0008] As a further technical solution, the plant-based mosquito repellent composition is used to prepare mosquito repellent liquid or mosquito repellent cream.

[0009] As a further technical solution, the mosquito repellent liquid prepared from the composition is based on a mass of 1000 mg. The formula consists of the plant-based mosquito repellent composition, 95% food-grade ethanol, and purified water, with the addition of food-grade 1,2-propanediol. The amounts of each component are: 500 mg of 95% food-grade ethanol, 150-180 mg of purified water, 50 mg of food-grade 1,2-propanediol, and the remainder being the plant-based mosquito repellent composition. The food-grade 1,2-propanediol is used as a co-solvent to improve the compatibility of the components.

[0010] As a further technical solution, the preparation method of the mosquito repellent liquid includes the following steps: Weigh out 95% food-grade ethanol, purified water, and food-grade 1,2-propanediol according to the formula, place them in a light-proof glass container, and stir at 200~250r / min for 5~8min under constant temperature of 25℃ until well mixed to obtain a composite solvent for later use. Weigh out the plant-based mosquito repellent composition according to the formula, slowly add it to the composite solvent, and stir at 250-300 r / min for 15-20 min at 25-30℃ and in the dark for 15-20 min until the composition is completely dissolved to obtain the initial mosquito repellent liquid. The initial mosquito repellent solution was sterile filtered through a 0.22μm microporous membrane to remove microorganisms and tiny impurities. The sterile filtered mosquito repellent liquid is filled into a light-blocking spray bottle and sealed to obtain the finished mosquito repellent liquid.

[0011] As a further technical solution, the mosquito repellent cream prepared from the aforementioned composition, by weight, comprises the aforementioned plant-based mosquito repellent composition, pharmaceutical-grade white petrolatum, liquid paraffin, glycerin, and refined anhydrous lanolin, and may also contain beeswax and vitamin E acetate; the amounts of each component are as follows: 12-20 parts of plant-based mosquito repellent composition, 40-50 parts of pharmaceutical-grade white petrolatum, 10-15 parts of liquid paraffin, 3-5 parts of glycerin, 5-10 parts of refined anhydrous lanolin, 3-5 parts of beeswax, and 0.1-0.3 parts of vitamin E acetate; the beeswax enhances the film-forming properties of the cream, and the vitamin E acetate enhances the antioxidant properties of the cream.

[0012] As a further technical solution, the preparation method of the mosquito repellent cream includes the following steps: Weigh out pharmaceutical-grade white petrolatum, refined anhydrous lanolin, beeswax, and liquid paraffin according to the formula, place them in a water-cooled kettle, and stir until completely melted under constant temperature of 60~65℃ to obtain an oil phase matrix, and keep it warm for later use. Weigh out glycerol and purified water according to the formula, with the amount of purified water being 5% to 8% of the mass of the oil phase matrix. Place them in a stirring container and mix well to obtain the aqueous phase. Add vitamin E acetate to the aqueous phase and stir to dissolve. Set aside for later use. The aqueous phase is slowly added to the oil phase matrix, and the mixture is stirred and emulsified at 300-350 r / min at 60-65℃ for 15-20 min. Then the temperature is lowered to 35-40℃ to obtain the paste base material. Weigh the plant-based mosquito repellent composition according to the formula, slowly add it to the paste base, and stir at 250~300r / min for 10~15min until it is evenly mixed. The mixture was placed in a vacuum degassing kettle and degassed for 5 to 8 minutes under a vacuum of -0.05 to -0.07 MPa. Then it was allowed to cool naturally to room temperature, filled and sealed to obtain the finished mosquito repellent cream.

[0013] As a further technical solution, all steps of the preparation process are carried out in a clean environment with a temperature of 20~30℃ and a relative humidity of 50%~60%; all containers in contact with materials are made of glass or food-grade stainless steel and are used after high-temperature and high-pressure sterilization; the entire preparation process is carried out in a light-proof manner to prevent the core mosquito-repellent ingredients from photodegrading and becoming ineffective.

[0014] The preparation method of the plant-based mosquito repellent composition is as follows: weigh out Sophora flavescens extract, eucalyptol, montmorillonite glycol, and natural Echinacea purpurea extract according to the weight parts, place them in a light-proof and sealed container, and stir for 5 to 8 minutes at 25~30℃ and 200~250 r / min until well mixed.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The plant-based mosquito-repellent composition of this invention uses Sophora flavescens extract, eucalyptol, menthol, and natural Echinacea purpurea extract as core components, achieving complementary functions and synergistic effects through scientific formulation. Eucalyptol and menthol are natural plant essential oil monomers that can directly act on the olfactory system of mosquitoes, interfering with their recognition of human scent and repelling them at the source. Eucalyptol also has a certain antibacterial effect, reducing the growth of microorganisms on the skin surface. Sophora flavescens extract is prepared using a combined low-temperature enzymatic hydrolysis-stepwise alcohol extraction-microfiltration purification process, and natural menthol extract is added as a drug guide. This not only significantly improves the extraction rate of mosquito-repellent active ingredients such as alkaloids in Sophora flavescens, but the penetration-enhancing effect of menthol also allows the Sophora flavescens extract to... Other mosquito-repellent ingredients quickly penetrate and adhere to the skin surface, forming a stable repellent film. Meanwhile, Sophora flavescens alkaloids have significant anti-inflammatory and antipruritic effects, relieving skin discomfort caused by mosquito bites. Natural purple coneflower extract is a water extract with a chicoric acid content of ≥4%. Chicoric acid can enhance the repellent activity of eucalyptol and menthol against mosquitoes, slow down the volatilization rate of essential oil components, and prolong the mosquito-repellent effect. At the same time, the synergistic effect of chicoric acid and Sophora flavescens alkaloids can further enhance the anti-inflammatory and anti-swelling effects, and quickly repair damaged skin after mosquito bites.

[0016] This invention achieves a multi-dimensional synergistic effect through the scientific proportioning of each component and the control of the preparation process, thereby improving the overall performance of the product from the perspective of the overall formulation. In terms of mosquito repellency, the olfactory repellency of eucalyptol and montmorillonite combined with the synergistic effects of Sophora flavescens extract and natural Echinacea purpurea extract form a dual mosquito repellency system of "repellency and synergistic effect." Compared with single essential oil blends, this system can significantly improve the mosquito repellency rate, and the active ingredients are more stable and less prone to volatilization and inactivation due to environmental factors. In terms of skin care, the anti-inflammatory synergy of Sophora flavescens alkaloids and Echinacea purpurea chicoric acid, combined with the penetration-enhancing effect of menthol, allows the soothing ingredients to quickly act on the dermis of the bite site, solving the problems of slow and superficial soothing effects of traditional plant-based mosquito repellent products. At the same time, the preparation process of Sophora flavescens extract adopts low-temperature, light-protected, and gentle extraction and purification methods, which fully preserves the plant's active ingredients. When combined with natural Echinacea purpurea extract, eucalyptol, and montmorillonite, the components have good compatibility and no antagonistic effects, ensuring the overall stability and effectiveness of the composition. In addition, the composition can be flexibly prepared into two formulations: mosquito repellent liquid and mosquito repellent cream. The preparation process of both formulations follows the principle of mild operation, avoiding light and controlling temperature throughout the process, and no artificial preservatives or solubilizers are added. This not only protects the plant active ingredients from being destroyed, but also ensures the naturalness of the formula, solving the problems of existing plant mosquito repellent products having a single formulation and the preparation process easily leading to ingredient inactivation.

[0017] The plant-based mosquito repellent composition and preparation method of the present invention fundamentally solve the core problems of existing plant-based mosquito repellent products, such as poor mosquito repellent effect, short effective duration, and lack of skin soothing function, through the functional optimization of single components and the synergistic combination of multiple components, while taking into account the naturalness and safety of the product. The preparation of Sophora flavescens extract utilizes a combined low-temperature enzymatic hydrolysis-stepwise alcohol extraction-microfiltration purification process, with the addition of natural menthol extract as a drug guide. This effectively improves the extraction rate and utilization efficiency of plant active ingredients, reduces waste of plant resources, and the preparation process is green and environmentally friendly, generating no harmful waste. Since all components are of natural plant origin and no artificial synthetic additives are added throughout the preparation process, the product is gentle and non-irritating, suitable for infants, people with sensitive skin, pregnant women, and other groups, solving the irritation problem of chemically synthesized mosquito repellent products. It achieves the dual function of mosquito repellent and skin soothing and anti-inflammatory properties, and can be prepared in two formulations: mosquito repellent liquid and mosquito repellent cream. The liquid is easy to apply and leaves no residue, suitable for quick daily mosquito repellent, while the cream has good adhesion and long-lasting mosquito repellent effect, suitable for long-term outdoor mosquito repellent, meeting the needs of different scenarios and enhancing the product's practicality and applicability. Attached Figure Description

[0018] Figure 1 A flowchart illustrating the preparation method of Sophora flavescens extract for a plant-based mosquito repellent composition. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention provides a plant-based mosquito repellent composition, which, by weight, comprises 0.1-5 parts of Sophora flavescens extract, 5-15 parts of eucalyptol, 5-20 parts of menthol, and 0.02-0.1 parts of natural purple coneflower extract; wherein the natural purple coneflower extract is an aqueous extract with a chicoric acid content ≥4%.

[0021] In this invention, the Sophora flavescens extract is preferably prepared by a combined process of low-temperature enzymatic hydrolysis-stepwise alcohol extraction-microfiltration purification, with natural menthol extract added as a drug guide during the preparation process; the natural menthol extract is a cold extract of peppermint stems and leaves with a menthol content ≥98%.

[0022] The preferred method for preparing the Sophora flavescens extract includes the following steps: Sophora flavescens root powder is pulverized and passed through a 40-60 mesh sieve; purified water is added in 3-5 times the weight of the Sophora flavescens root powder; then, 2%-3% of a compound enzyme and 1.2%-1.5% of a natural menthol extract are added; the mixture is enzymatically hydrolyzed for 1-2 hours at a constant temperature of 35-40°C and a stirring speed of 80-100 r / min to obtain the Sophora flavescens enzymatic hydrolysate. The compound enzyme is a mixture of pectinase and cellulase with an enzyme activity ratio of 2:1; 2-3 times the volume of 30% food-grade ethanol is added to the Sophora flavescens enzymatic hydrolysate; the mixture is then stirred at 25-28°C... Extract the extract at room temperature for 2 hours under light-protected conditions, and filter to obtain the primary extract. Add 2-3 times the volume of 60% food-grade ethanol to the filter residue, and extract at room temperature for 2 hours under light-protected conditions at 25-28℃, and filter to obtain the secondary extract. Combine the primary and secondary extracts, and concentrate under reduced pressure at a vacuum of -0.08 to -0.10 MPa and a temperature of 40-45℃ to 1 / 5 to 1 / 4 of the original extract volume to obtain Sophora flavescens concentrate. Purify and filter the Sophora flavescens concentrate through a 0.45μm ceramic microfiltration membrane to remove insoluble impurities, and then concentrate to a solid content of 10% to 20% to obtain Sophora flavescens extract.

[0023] In this invention, the plant-based mosquito repellent composition is preferably used to prepare mosquito repellent liquid or mosquito repellent cream.

[0024] The mosquito repellent liquid prepared from the composition is based on 1000 mg by weight. The preferred formulation consists of the plant-based mosquito repellent composition, 95% food-grade ethanol, purified water, and food-grade 1,2-propanediol. The preferred amounts of each component are: 500 mg of 95% food-grade ethanol, 150-180 mg of purified water, 50 mg of food-grade 1,2-propanediol, and the remainder being the plant-based mosquito repellent composition.

[0025] The preferred method for preparing the mosquito repellent liquid includes the following steps: Weigh 95% food-grade ethanol, purified water, and food-grade 1,2-propanediol according to the formula amount, place them in a light-proof glass container, and stir at 200-250 r / min for 5-8 min under constant temperature of 25℃ to obtain a composite solvent for later use; Weigh the plant-based mosquito repellent composition according to the formula amount, slowly add it to the composite solvent, and stir at 250-300 r / min for 15-20 min under light-proof conditions at 25-30℃ until the composition is completely dissolved to obtain the initial mosquito repellent liquid; Sterilize the initial mosquito repellent liquid through a 0.22 μm microporous membrane to remove microorganisms and tiny impurities; Fill the sterile filtered mosquito repellent liquid into a light-proof spray bottle and seal it to obtain the finished mosquito repellent liquid.

[0026] The mosquito repellent cream prepared from the composition is preferably composed of the plant-based mosquito repellent composition, pharmaceutical-grade white petrolatum, liquid paraffin, glycerin, and refined anhydrous lanolin, and may also contain beeswax and vitamin E acetate. The preferred amounts of each component are: 12-20 parts of plant-based mosquito repellent composition, 40-50 parts of pharmaceutical-grade white petrolatum, 10-15 parts of liquid paraffin, 3-5 parts of glycerin, 5-10 parts of refined anhydrous lanolin, 3-5 parts of beeswax, and 0.1-0.3 parts of vitamin E acetate.

[0027] The preferred method for preparing the mosquito repellent cream includes the following steps: Weigh pharmaceutical-grade white petrolatum, refined anhydrous lanolin, beeswax, and liquid paraffin according to the formula, place them in a water-cooled autoclave, and stir until completely melted under constant temperature conditions of 60-65°C to obtain an oil phase matrix, which is then kept warm for later use; Weigh glycerin and purified water according to the formula, wherein the amount of purified water is 5%-8% of the mass of the oil phase matrix, place them in a stirring container and mix well to obtain an aqueous phase; Add vitamin E acetate to the aqueous phase and stir to dissolve, which is then set aside; Slowly add the aqueous phase to the oil phase matrix... Emulsify the mixture at 300-350 rpm for 15-20 minutes at 60-65℃, then cool it to 35-40℃ to obtain a paste base. Weigh the plant-based mosquito repellent composition according to the formula, slowly add it to the paste base, and stir at 250-300 rpm for 10-15 minutes until it is evenly mixed. Place the mixture in a vacuum degassing kettle and degas it for 5-8 minutes under a vacuum of -0.05 to -0.07 MPa. Then allow it to cool naturally to room temperature, fill and seal it to obtain the finished mosquito repellent paste.

[0028] In this invention, all steps in the preparation of mosquito repellent liquid or mosquito repellent cream are preferably carried out in a clean environment with a temperature of 20~30℃ and a relative humidity of 50%~60%; all containers in contact with materials are made of glass or food-grade stainless steel and are used after high-temperature and high-pressure sterilization; the entire preparation process is carried out in the dark.

[0029] The present invention also provides a method for preparing the above-mentioned plant-based mosquito repellent composition. The following steps are taken by weight: Sophora flavescens extract, eucalyptol, montmorillonite glycol, and natural Echinacea purpurea extract are weighed and placed in a light-proof and sealed container. The mixture is stirred for 5 to 8 minutes at 25 to 30°C and 200 to 250 r / min until homogeneous to obtain the plant-based mosquito repellent composition.

[0030] The plant-based mosquito repellent composition provided by this invention is a pure plant-based formula. The components work synergistically to achieve a highly effective mosquito repellent effect. At the same time, the combination of Sophora flavescens extract and natural Echinacea purpurea extract also has a soothing and anti-inflammatory effect, preventing skin redness and itching after mosquito bites. The entire preparation process uses mild conditions to preserve the activity of each plant component. Moreover, the formula contains no artificially synthesized mosquito repellents or preservatives, making it highly safe and suitable for all types of people, including infants and children with sensitive skin. In addition, this composition can be flexibly prepared into mosquito repellent liquid or mosquito repellent cream to meet the needs of different usage scenarios. The prepared mosquito repellent liquid is easy to apply, evaporates easily without residue, and the mosquito repellent cream has good adhesion and a long-lasting mosquito repellent effect.

[0031] To further illustrate the present invention, the following detailed description is provided through the embodiments. In the following embodiments of the present invention: the Sophora flavescens root powder used is obtained by grinding commercially available high-quality Sophora flavescens roots; the pectinase and cellulase are food-grade enzyme preparations; the natural menthol extract is a cold extract of peppermint stems and leaves with a menthol content of 98.5%; the natural Echinacea purpurea extract is an aqueous extract with a chicoric acid content of 4.2%; eucalyptol and menthol are food-grade plant essential oil monomers; 95% food-grade ethanol and food-grade 1,2-propanediol are commercially available food additives; and the pharmaceutical-grade white petrolatum, liquid paraffin, glycerin, refined anhydrous lanolin, beeswax, and vitamin E acetate are all pharmaceutical-grade raw materials.

[0032] Example 1: Step 1: Preparation of Sophora flavescens extract: Take Sophora flavescens root powder, pulverize it, and pass it through a 40-mesh sieve. Add three times the weight of purified water to the powder, then add 2% (by weight of the powder) of a compound enzyme and 1.2% (by weight of the powder) of natural menthol extract. The compound enzyme is a mixture of pectinase and cellulase at an enzyme activity ratio of 2:1. Enzymatically hydrolyze the mixture at 35℃ and 80 rpm for 1 hour to obtain the Sophora flavescens enzymatic hydrolysate. Add two volumes of 30% food-grade ethanol to the hydrolysate and extract at 25℃ in the dark for 2 hours. Filter the extract. The first extract was obtained, and 2 times the volume of 60% food-grade ethanol was added to the filter residue. The extract was then extracted at room temperature for 2 hours at 25°C in the dark. The extract was then filtered to obtain the second extract. The first and second extracts were combined and concentrated under reduced pressure at -0.08 MPa and 40°C to 1 / 5 of the original total volume to obtain Sophora flavescens concentrate. The Sophora flavescens concentrate was purified and filtered through a 0.45 μm ceramic microfiltration membrane to remove insoluble impurities, and then concentrated to a solid content of 10% to obtain Sophora flavescens extract.

[0033] Step 2: Preparation of plant-based mosquito repellent composition: Weigh out 0.1 parts of Sophora flavescens extract, 5 parts of eucalyptol, 5 parts of montmorillonite glycol, and 0.02 parts of natural purple coneflower extract according to the weight ratio. Place them in a light-proof and sealed container and stir for 5 minutes at 25°C and 200 r / min to obtain a plant-based mosquito repellent composition.

[0034] Step 3: Prepare mosquito repellent solution: Based on a mass ratio of 1000mg, weigh 500mg of 95% food-grade ethanol, 150mg of purified water, and 50mg of food-grade 1,2-propanediol, place them in a light-proof glass container, and stir at 200r / min for 5min at a constant temperature of 25℃ to obtain a composite solvent for later use; weigh 250mg of the plant-based mosquito repellent composition and slowly add it to the composite solvent, stirring at 250r / min for 15min at 25℃ in the dark until the composition is completely dissolved to obtain the initial mosquito repellent solution; sterilize the initial mosquito repellent solution through a 0.22μm microporous membrane to remove microorganisms and tiny impurities; fill the sterile filtered mosquito repellent solution into light-proof spray bottles and seal them to obtain the finished mosquito repellent solution; the entire preparation process is carried out in a clean environment at 20℃ and 50% relative humidity, the container is made of glass and has undergone high-temperature and high-pressure sterilization, and the entire process is carried out in the dark.

[0035] Step 4: Prepare mosquito repellent cream: Weigh out 12 parts by weight of the plant-based mosquito repellent composition, 40 parts by weight of pharmaceutical-grade white petrolatum, 10 parts by weight of liquid paraffin, 3 parts by weight of glycerin, 5 parts by weight of refined anhydrous lanolin, 3 parts by weight of beeswax, and 0.1 parts by weight of vitamin E acetate; weigh out the pharmaceutical-grade white petrolatum, refined anhydrous lanolin, beeswax, and liquid paraffin, place them in a water-cooled autoclave, and stir until completely melted at a constant temperature of 60°C to obtain the oil phase matrix, and keep it warm for later use; weigh out glycerin and purified water, with the amount of purified water being 5% of the mass of the oil phase matrix, place them in a stirring container and mix well to obtain the aqueous phase, add vitamin E acetate to the aqueous phase and stir to dissolve, and set aside; slowly add the aqueous phase to the oil... In the phase matrix, the mixture was emulsified by stirring at 300 r / min for 15 min at 60℃, and then cooled to 35℃ to obtain the paste base material. The plant-based mosquito repellent composition was weighed and slowly added to the paste base material, and stirred at 250 r / min for 10 min until it was uniformly mixed. The mixture was placed in a vacuum degassing kettle and degassed for 5 min under a vacuum of -0.05 MPa, and then allowed to cool naturally to room temperature. The mixture was then filled and sealed to obtain the finished mosquito repellent paste. The entire preparation process was carried out in a clean environment with a temperature of 20℃ and a relative humidity of 50%. The container was made of food-grade stainless steel and was sterilized by high temperature and high pressure. The entire process was carried out in the dark.

[0036] Safety: Patch test confirmed that it is non-allergenic (compliant with ISO 10993 standard).

[0037] Example 2: Step 1: Preparation of Sophora flavescens extract: Powdered Sophora flavescens root powder was pulverized and passed through a 60-mesh sieve. Five times the weight of purified water was added, followed by 3% (by weight of the Sophora flavescens root powder) of a compound enzyme and 1.5% (by weight of the Sophora flavescens root powder) of natural menthol extract. The compound enzyme was a mixture of pectinase and cellulase at an enzyme activity ratio of 2:1. Enzymatic hydrolysis was performed at 40℃ and 100 rpm for 2 hours to obtain Sophora flavescens enzymatic hydrolysate. Three times the volume of 30% food-grade ethanol was added to the hydrolysate, and extraction was carried out at 28℃ in the dark for 2 hours. The primary extract was obtained by filtration. Three times the volume of 60% food-grade ethanol was added to the filter residue, and the extract was extracted at room temperature for 2 hours at 28°C in the dark. The extract was then filtered to obtain a secondary extract. The primary and secondary extracts were combined and concentrated under reduced pressure at a vacuum of -0.10 MPa and a temperature of 45°C to 1 / 4 of the original extract volume to obtain a concentrated Sophora flavescens extract. The concentrated Sophora flavescens extract was purified by filtration through a 0.45 μm ceramic microfiltration membrane to remove insoluble impurities, and then concentrated to a solid content of 20% to obtain a Sophora flavescens extract.

[0038] Step 2: Preparation of plant-based mosquito repellent composition: Weigh out 5 parts of Sophora flavescens extract, 15 parts of eucalyptol, 20 parts of montmorillonite glycol, and 0.1 parts of natural purple coneflower extract according to the weight ratio. Place them in a light-proof and sealed container and stir for 8 minutes at 30°C and 250 r / min to obtain a plant-based mosquito repellent composition.

[0039] Step 3: Prepare mosquito repellent solution: Based on a mass ratio of 1000mg, weigh 500mg of 95% food-grade ethanol, 180mg of purified water, and 50mg of food-grade 1,2-propanediol, place them in a light-proof glass container, and stir at 250r / min for 8 minutes at a constant temperature of 25℃ to obtain a composite solvent for later use; weigh 220mg of the plant-based mosquito repellent composition and slowly add it to the composite solvent, and stir at 300r / min for 20 minutes at 30℃ in the dark until the composition is completely dissolved to obtain the initial mosquito repellent solution; sterilize the initial mosquito repellent solution through a 0.22μm microporous membrane to remove microorganisms and tiny impurities; fill the sterile filtered mosquito repellent solution into light-proof spray bottles and seal them to obtain the finished mosquito repellent solution; the entire preparation process is carried out in a clean environment at 30℃ and 60% relative humidity, the container is made of glass and has undergone high-temperature and high-pressure sterilization, and the entire process is carried out in the dark.

[0040] Step 4: Prepare mosquito repellent cream: Weigh out 20 parts by weight of the plant-based mosquito repellent composition, 50 parts by weight of pharmaceutical-grade white petrolatum, 15 parts by weight of liquid paraffin, 5 parts by weight of glycerin, 10 parts by weight of refined anhydrous lanolin, 5 parts by weight of beeswax, and 0.3 parts by weight of vitamin E acetate; weigh out the pharmaceutical-grade white petrolatum, refined anhydrous lanolin, beeswax, and liquid paraffin, place them in a water-cooled autoclave, and stir until completely melted at a constant temperature of 65°C to obtain the oil phase matrix, and keep it warm for later use; weigh out glycerin and purified water, with the amount of purified water being 8% of the mass of the oil phase matrix, place them in a stirring container and mix well to obtain the aqueous phase, add vitamin E acetate to the aqueous phase and stir to dissolve, and set aside; slowly add the aqueous phase to the oil... In the phase matrix, the mixture was emulsified at 350 r / min for 20 min at 65℃, and then cooled to 40℃ to obtain the paste base material. The plant-based mosquito repellent composition was weighed and slowly added to the paste base material, and stirred at 300 r / min for 15 min until it was uniformly mixed. The mixture was placed in a vacuum degassing kettle and degassed at a vacuum degree of -0.07 MPa for 8 min, and then cooled naturally to room temperature. It was then filled and sealed to obtain the finished mosquito repellent paste. The entire preparation process was carried out in a clean environment with a temperature of 30℃ and a relative humidity of 60%. The container was made of food-grade stainless steel and was sterilized by high temperature and high pressure. The entire process was carried out in the dark.

[0041] Safety: Patch test confirmed that it is non-allergenic (compliant with ISO 10993 standard).

[0042] Example 3: Step 1: Preparation of Sophora flavescens extract: Powdered Sophora flavescens root powder was pulverized and passed through a 50-mesh sieve. Four times the weight of purified water was added, along with 2.5% (by weight of the Sophora flavescens root powder) of a compound enzyme and 1.35% (by weight of the Sophora flavescens root powder) of natural menthol extract. The compound enzyme was a mixture of pectinase and cellulase at an enzyme activity ratio of 2:1. Enzymatic hydrolysis was performed at 38℃ and 90 rpm for 1.5 hours to obtain the Sophora flavescens enzymatic hydrolysate. Two and a half times the volume of 30% food-grade ethanol were added to the hydrolysate, and extraction was carried out at 26℃ in the dark for 2 hours. The primary extract was obtained by filtration. 2.5 times the volume of 60% food-grade ethanol was added to the filter residue, and the extract was carried out at room temperature for 2 hours at 26°C in the dark. The extract was then filtered to obtain a secondary extract. The primary and secondary extracts were combined and concentrated under reduced pressure at -0.09 MPa and 42°C to 9 / 40 of the original extract volume, yielding a concentrated Sophora flavescens extract. This concentrated extract was purified by filtration through a 0.45 μm ceramic microfiltration membrane to remove insoluble impurities, and then concentrated to a solid content of 15%, yielding the Sophora flavescens extract.

[0043] Step 2: Preparation of plant-based mosquito repellent composition: Weigh out 2.55 parts of Sophora flavescens extract, 10 parts of eucalyptol, 12.5 parts of menthol, and 0.06 parts of natural purple coneflower extract according to the weight ratio. Place them in a light-proof and sealed container and stir for 6.5 minutes at 28°C and 225 r / min to obtain a plant-based mosquito repellent composition.

[0044] Step 3: Prepare mosquito repellent solution: Based on a mass ratio of 1000mg, weigh 500mg of 95% food-grade ethanol, 165mg of purified water, and 50mg of food-grade 1,2-propanediol, place them in a light-proof glass container, and stir at 225r / min for 6.5min at a constant temperature of 25℃ until well mixed to obtain a composite solvent for later use; weigh 235mg of the plant-based mosquito repellent composition and slowly add it to the composite solvent, and stir at 275r / min for 17.5min at 28℃ in the dark until the composition is completely dissolved to obtain the initial mosquito repellent solution; sterilize the initial mosquito repellent solution through a 0.22μm microporous membrane to remove microorganisms and tiny impurities; fill the sterile filtered mosquito repellent solution into light-proof spray bottles and seal them to obtain the finished mosquito repellent solution; the entire preparation process is carried out in a clean environment at 25℃ and 55% relative humidity, the container is made of glass and has undergone high-temperature and high-pressure sterilization, and the entire process is carried out in the dark.

[0045] Step 4: Prepare mosquito repellent cream: Weigh out 16 parts by weight of the plant-based mosquito repellent composition, 45 parts by weight of pharmaceutical-grade white petrolatum, 12.5 parts by weight of liquid paraffin, 4 parts by weight of glycerin, 7.5 parts by weight of refined anhydrous lanolin, 4 parts by weight of beeswax, and 0.2 parts by weight of vitamin E acetate; weigh out the pharmaceutical-grade white petrolatum, refined anhydrous lanolin, beeswax, and liquid paraffin, place them in a water-cooled autoclave, and stir until completely melted at a constant temperature of 62°C to obtain the oil phase matrix, and keep it warm for later use; weigh out glycerin and purified water, with the amount of purified water being 6.5% of the mass of the oil phase matrix, place them in a stirring container and mix well to obtain the aqueous phase, add vitamin E acetate to the aqueous phase and stir to dissolve, and set aside; slowly add the aqueous phase to the oil... In the phase matrix, the mixture was emulsified at 325 r / min for 17.5 min at 62℃, and then cooled to 37℃ to obtain the ointment base. The plant-based mosquito repellent composition was weighed and slowly added to the ointment base, and stirred at 275 r / min for 12.5 min until it was uniformly mixed. The mixture was placed in a vacuum degassing kettle and degassed at a vacuum of -0.06 MPa for 6.5 min, and then allowed to cool naturally to room temperature. The mixture was then filled and sealed to obtain the finished mosquito repellent ointment. The entire preparation process was carried out in a clean environment at 25℃ and 55% relative humidity. The containers were made of food-grade stainless steel and were sterilized by high temperature and high pressure. The entire process was carried out in the dark.

[0046] Safety: Patch test confirmed that it is non-allergenic (compliant with ISO 10993 standard).

[0047] Comparative Example 1: The preparation method of Example 3 of the present invention is used, except that: no natural purple coneflower extract is added to the prepared plant mosquito repellent composition, and the amount of other raw materials and preparation process parameters are the same as those in Example 3.

[0048] Comparative Example 2: The preparation method of Example 3 of this invention is used, except that: when preparing Sophora flavescens extract, natural menthol extract is not added, and the low-temperature enzymatic hydrolysis-stepwise alcohol extraction process is not used. Only a single water extraction process is used. The specific preparation steps are as follows: Sophora flavescens root powder of the same mass as in Example 3 is crushed and passed through a 50-mesh sieve. Four times the mass of purified water of Sophora flavescens root powder is added. The mixture is stirred and extracted for 3 hours at 38°C and 90 r / min. The water extract is obtained by filtration and concentrated under reduced pressure at a vacuum of -0.09 MPa and a temperature of 42°C to a solid content of 15% to obtain Sophora flavescens water extract. The amount of other raw materials and subsequent preparation process parameters are the same as in Example 3.

[0049] test: To verify the application effect of the plant-based mosquito repellent composition of the present invention, the mosquito repellent liquids and ointments prepared in Examples 1, 2, and 3, and Comparative Examples 1 and 2 were tested for effective mosquito repellent duration, mosquito bite protection rate, and skin soothing effect. The test methods and results are as follows. All tests were conducted in a standard mosquito test chamber (temperature 25℃, relative humidity 60%, Aedes albopictus adult mosquito density 100 mosquitoes / m²). 3 The trial was conducted with 20 healthy adults, half male and half female, who had no history of mosquito bite allergies.

[0050] Experiment 1: Test of the effective duration of mosquito repellent: The skin on the inside of the volunteer's forearm was divided into 5cm×5cm test areas, disinfected with 75% medical alcohol and allowed to air dry naturally. Mosquito repellent liquid group: Spray the corresponding sample evenly on the test area at a rate of 0.1 mL / cm², and let it air dry naturally; Mosquito repellent cream group: Apply the corresponding sample evenly to the test area at a rate of 0.05 g / cm², and let it air dry naturally. The treated test area was exposed to a standard mosquito test chamber, and mosquito bites were observed every 0.5 hours. The time from application / spraying to the first appearance of red and swollen mosquito bites was recorded as the effective duration of mosquito repellency. The average of the test results of 20 volunteers was taken as the final data. The experiment was repeated 3 times, and the average of the three results was taken.

[0051] Experimental results: Table 1. Test results of mosquito repellent effectiveness duration. The mosquito repellent liquids and ointments prepared in Examples 1, 2, and 3 all exhibited excellent and sustained mosquito repellent effects.

[0052] The reason for the significant decrease in mosquito repellency in Comparative Example 1 is the absence of natural purple coneflower extract. This ingredient has a synergistic mosquito repellent effect with eucalyptol and menthol. Chicoric acid can enhance the repellency of plant essential oils against mosquitoes. At the same time, it can also work synergistically with sophora flavescens extract to improve the stability of the ingredients and reduce the volatilization of essential oils. Without it, the essential oil ingredients volatilize rapidly, and the mosquito repellency time is greatly shortened. The reason why Comparative Example 2 had the worst mosquito-repellent effect was that it used commercially available common Sophora flavescens extract, without employing the low-temperature enzymatic hydrolysis-stepwise alcohol extraction-microfiltration purification combined process of the present invention, and without adding natural menthol extract as a drug guide. This resulted in a low extraction rate of mosquito-repellent active ingredients in the Sophora flavescens extract, and the lack of the penetration-promoting effect of menthol. As a result, the various mosquito-repellent ingredients could not effectively act on the skin surface to form a continuous repellent film. At the same time, the common Sophora flavescens extract had a high impurity content, which affected the compatibility with other ingredients and further reduced the mosquito-repellent effect.

[0053] Experiment 2: Mosquito bite protection rate test The experimental grouping and skin treatment methods were the same as in Experiment 1, with an additional blank control group (skin was disinfected only, without applying / spraying the sample). All volunteers' test areas were simultaneously exposed to a standard mosquito test chamber. After 3 hours of continuous exposure, the areas were removed, and the number of mosquito bite redness and swelling in each test area was counted. Formula for calculating mosquito bite protection rate: Protection rate (%) = (Average number of bites in the blank control group - Average number of bites in the sample group) / Average number of bites in the blank control group × 100%; The experiment was repeated three times, and the average of the three trials was taken as the final data.

[0054] Experimental results: Table 2 Results of mosquito bite protection rate test The mosquito bite protection rates of Examples 1, 2, and 3 are all above 90%, with Example 2 showing a protection rate close to 100%. This indicates that the plant-based mosquito repellent composition of the present invention can effectively block mosquito bites, and the synergistic effect of each component can form a highly efficient mosquito repellency barrier.

[0055] The protection rate of Comparative Example 1 is only 70%~75%. Due to the lack of natural purple coneflower extract, the repellent effects of eucalyptol and menthol cannot be fully exerted, and mosquitoes can still bite the skin. Only Sophora flavescens extract and a small amount of essential oil can achieve partial repellency. The protection rate of Comparative Example 2 was 65%~70%. In addition to the low content of active ingredients in Sophora flavescens extract, ordinary Sophora flavescens extract does not have effective soothing and anti-inflammatory components, and redness and swelling after mosquito bites are more likely to appear. At the same time, poor compatibility of ingredients leads to discontinuity of the repellent film, and mosquitoes can bite the skin through gaps, further reducing the protection rate.

[0056] Experiment 3: Skin Soothing Effect Test First, expose the inner forearm skin of the volunteer to a standard mosquito test chamber for 10 minutes to induce red and swollen spots from mosquito bites. The test was conducted after the red and swollen spots became obvious (30 minutes after they appeared). The corresponding samples were evenly applied to the skin areas with redness and swelling. The amount of mosquito repellent liquid applied was 0.1 mL / cm², the amount of mosquito repellent cream applied was 0.05 g / cm², and the blank control group was only applied with an equal amount of purified water. The reduction of redness and swelling was observed and recorded at 15 min, 30 min, and 60 min after application. A redness and swelling reduction scoring method was used: 0 points (no reduction, redness and swelling worsened), 1 point (slight reduction, redness and swelling area reduced by less than 10%), 2 points (moderate reduction, redness and swelling area reduced by 10%~30%), 3 points (significant reduction, redness and swelling area reduced by 30%~50%), 4 points (basic reduction, redness and swelling area reduced by more than 50%), and 5 points (complete reduction, no redness and swelling). The average score of 20 volunteers was used as the final data. The experiment was repeated 3 times, and the average of the three scores was taken.

[0057] Experimental results: Table 3. Results of the skin soothing effect test (average score) The mosquito repellent liquid and mosquito repellent cream prepared in Examples 1, 2, and 3 all have significant skin soothing effects. The mosquito repellent cream is more effective than the mosquito repellent liquid because the base material of the cream has better adhesion, and the active ingredients can act on the bite site for a longer time. The redness and swelling of Example 2 completely subsided after 60 minutes, the soothing effect of Example 3 is close to that of Example 2, and Example 1 can also achieve basic subsidence. This shows that the composition of the present invention not only has a mosquito repellent effect, but also effectively relieves the problem of skin redness and swelling after mosquito bites.

[0058] The soothing effect of Comparative Example 1 was poor because it lacked natural purple coneflower extract. This ingredient works synergistically with the alkaloids in Sophora flavescens extract to reduce inflammation and swelling. Without it, the soothing effect of Sophora flavescens extract alone could not quickly relieve the allergic reaction after mosquito bites, and the redness and swelling subsided much slower. Comparative ratio 2 showed the worst soothing effect because the commercially available common Sophora flavescens extract used was not purified, resulting in a low content of active anti-inflammatory components and the absence of the penetration-enhancing effect of natural menthol extract. As a result, the effective ingredients could not quickly penetrate into the dermis layer of the skin and could not relieve the redness and inflammation under the skin. At the same time, impurities in the common extract may also cause slight irritation to the damaged skin after the bite, further delaying the resolution of redness and swelling.

[0059] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A plant-based mosquito repellent composition, characterized in that, By weight, it consists of 0.1-5 parts of Sophora flavescens extract, 5-15 parts of eucalyptol, 5-20 parts of menthol, and 0.02-0.1 parts of natural purple coneflower extract; the natural purple coneflower extract is an aqueous extract with a chicoric acid content ≥4%.

2. The plant-based mosquito repellent composition according to claim 1, characterized in that, The Sophora flavescens extract is prepared by a combined process of low-temperature enzymatic hydrolysis-stepwise alcohol extraction-microfiltration purification, with natural menthol extract added as a drug guide during the preparation process; the natural menthol extract is a cold extract of peppermint stems and leaves with a menthol content ≥98%.

3. The plant-based mosquito repellent composition according to claim 2, characterized in that, The preparation method of the Sophora flavescens extract includes the following steps: S1 Low-temperature enzymatic hydrolysis: Take Sophora flavescens root powder, crush it and pass it through a 40-60 mesh sieve, add 3-5 times the weight of purified water of Sophora flavescens root powder, then add 2%-3% of the weight of Sophora flavescens root powder compound enzyme and 1.2%-1.5% of the weight of Sophora flavescens root powder natural menthol extract, and enzymatically hydrolyze for 1-2 hours under constant temperature stirring conditions of 35-40℃ and 80-100 r / min to obtain Sophora flavescens enzymatic hydrolysate. The compound enzyme is a mixture of pectinase and cellulase with an enzyme activity ratio of 2:

1. S2 Stepwise Ethanol Extraction: Add 2-3 times the volume of 30% food-grade ethanol to the Sophora flavescens enzymatic hydrolysate, and extract at room temperature for 2 hours at 25-28℃ in the dark. Filter to obtain the first extract. Add 2-3 times the volume of 60% food-grade ethanol to the filter residue, and extract at room temperature for 2 hours at 25-28℃ in the dark. Filter to obtain the second extract. The primary and secondary extracts were combined and concentrated under reduced pressure at a vacuum of -0.08 to -0.10 MPa and a temperature of 40 to 45°C to 1 / 5 to 1 / 4 of the original total volume of the extract, to obtain a concentrated Sophora flavescens extract. S3 Microfiltration Purification: The concentrated Sophora flavescens extract is purified and filtered through a 0.45μm ceramic microfiltration membrane to remove insoluble impurities, and then concentrated to a solid content of 10%~20% to obtain Sophora flavescens extract.

4. The plant-based mosquito repellent composition according to claim 1, characterized in that, The plant-based mosquito repellent composition is used to prepare mosquito repellent liquids or mosquito repellent creams.

5. The plant-based mosquito repellent composition according to claim 4, characterized in that, The mosquito repellent prepared from the composition is based on a mass of 1000 mg. The formula consists of the plant-based mosquito repellent composition, 95% food-grade ethanol, purified water, and food-grade 1,2-propanediol. The amounts of each component are: 500 mg of 95% food-grade ethanol, 150-180 mg of purified water, 50 mg of food-grade 1,2-propanediol, and the remainder is the plant-based mosquito repellent composition.

6. The plant-based mosquito repellent composition according to claim 5, characterized in that, The preparation method of the mosquito repellent liquid includes the following steps: Weigh out 95% food-grade ethanol, purified water, and food-grade 1,2-propanediol according to the formula, place them in a light-proof glass container, and stir at 200~250r / min for 5~8min under constant temperature of 25℃ until well mixed to obtain a composite solvent for later use. Weigh out the plant-based mosquito repellent composition according to the formula, slowly add it to the composite solvent, and stir at 250-300 r / min for 15-20 min at 25-30℃ and in the dark for 15-20 min until the composition is completely dissolved to obtain the initial mosquito repellent liquid. The initial mosquito repellent solution was sterile filtered through a 0.22μm microporous membrane to remove microorganisms and tiny impurities. The sterile filtered mosquito repellent liquid is filled into a light-blocking spray bottle and sealed to obtain the finished mosquito repellent liquid.

7. The plant-based mosquito repellent composition according to claim 4, characterized in that, The mosquito repellent cream prepared from the composition comprises, by weight, the plant-based mosquito repellent composition, pharmaceutical-grade white petrolatum, liquid paraffin, glycerin, and refined anhydrous lanolin, and may also contain beeswax and vitamin E acetate; the amounts of each component are as follows: 12-20 parts of plant-based mosquito repellent composition, 40-50 parts of pharmaceutical-grade white petrolatum, 10-15 parts of liquid paraffin, 3-5 parts of glycerin, 5-10 parts of refined anhydrous lanolin, 3-5 parts of beeswax, and 0.1-0.3 parts of vitamin E acetate.

8. The plant-based mosquito repellent composition according to claim 7, characterized in that, The preparation method of the mosquito repellent cream includes the following steps: Weigh out pharmaceutical-grade white petrolatum, refined anhydrous lanolin, beeswax, and liquid paraffin according to the formula, place them in a water-cooled kettle, and stir until completely melted under constant temperature of 60~65℃ to obtain an oil phase matrix, and keep it warm for later use. Weigh out glycerol and purified water according to the formula, with the amount of purified water being 5% to 8% of the mass of the oil phase matrix. Place them in a stirring container and mix well to obtain the aqueous phase. Add vitamin E acetate to the aqueous phase and stir to dissolve. Set aside for later use. The aqueous phase is slowly added to the oil phase matrix, and the mixture is stirred and emulsified at 300-350 r / min at 60-65℃ for 15-20 min. Then the temperature is lowered to 35-40℃ to obtain the paste base material. Weigh the plant-based mosquito repellent composition according to the formula, slowly add it to the paste base, and stir at 250~300r / min for 10~15min until it is evenly mixed. The mixture was placed in a vacuum degassing kettle and degassed for 5 to 8 minutes under a vacuum of -0.05 to -0.07 MPa. Then it was allowed to cool naturally to room temperature, filled and sealed to obtain the finished mosquito repellent cream.

9. The plant-based mosquito repellent composition according to claim 6 or 8, characterized in that, All steps of the preparation process are carried out in a clean environment with a temperature of 20~30℃ and a relative humidity of 50%~60%; all containers in contact with materials are made of glass or food-grade stainless steel and are used after high temperature and high pressure sterilization; the entire preparation process is carried out in the dark.

10. A method for preparing the plant-based mosquito repellent composition according to any one of claims 1 to 9, characterized in that, Weigh out the following ingredients by weight: Sophora flavescens extract, eucalyptol, montmorillonite glycol, and natural purple coneflower extract. Place them in a light-proof, airtight container and stir for 5-8 minutes at 25-30℃ and 200-250 r / min until well mixed.

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