Highly water-soluble nano compound essential oil emulsion, preparation method and application thereof

Abstract

The application provides a high-water-solubility nano compound essential oil emulsion and a preparation method and application thereof, relates to the technical field of natural product application, and solves the technical problem of poor emulsification effect of existing compound essential oil emulsion in improving the stability of essential oil due to the difference of compound essential oil. The application is composed of the following raw materials in volume fraction: 2-3 parts of rose essential oil, 0.2-0.8 parts of lavender essential oil, 1.5-2.5 parts of frankincense essential oil, 0.5-1.5 parts of vetiver essential oil, 1.5-2.5 parts of orange flower essential oil, 0.5-1.5 parts of balm essential oil, 18-24 parts of glycerol fatty acid ester, 1-4 parts of cationic emulsifier and 50-70 parts of dispersant solution. The single essential oil in the application plays the role of respective components and forms a synergistic effect with other essential oils, and the synergistic effect is improved by reasonable compounding of the single essential oil.

Description

Technical Field

[0001] This invention relates to the field of natural product application technology, and more specifically, to a highly water-soluble nano-compound essential oil emulsion, its preparation method, and its application. Background Technology

[0002] Plant essential oils are volatile compounds with distinctive aromas and medicinal value extracted from plants. They are derived from the flowers, leaves, roots, bark, fruits, seeds, and resins of herbaceous plants, and are typically extracted using steam distillation, expression, cold maceration, or solvent extraction. Plant essential oils generally consist of small molecules, alkenes, alcohols, aldehydes, and ketones. Currently, plant essential oils are widely used in cosmetics, fragrances, food additives, and pharmaceuticals. The effects of essential oils include antibacterial, antioxidant, moisturizing, whitening, soothing, and promoting blood circulation, thus they are used in skin care, massage, aromatherapy, and traditional Chinese medicine preparations. Compound essential oils are made by mixing two or more single essential oils in a specific ratio, allowing them to harmonize and complement each other to enhance therapeutic effects. Many well-known cosmetic brands on the market contain essential oils and other oil-based ingredients. Different essential oils play important roles in the product, determining the overall moisturizing, repairing, and skin-feeling properties of the formula. However, due to the physical and chemical properties of essential oils, some essential oils are not very stable, are unstable to light and heat, or are easily oxidized and discolored, affecting their use. The poor water solubility of all essential oils also limits their application.

[0003] For example, the patent with publication number CN116270320A proposes an easily absorbed essential oil formula with antioxidant effect and its processing technology. This essential oil formula and processing technology utilizes baobab fruit oil and marula oil to achieve good antioxidant effects, rosehip oil and grapefruit oil to have repair and whitening effects, and jojoba oil to have good permeability, increase the skin's ability to absorb moisture, and keep the skin moisturized.

[0004] For example, patent CN104606112A discloses a plant essential oil mask made from a mixture of sea lily, peppermint, vitamin B5, rose essential oil, chamomile essential oil, calendula essential oil, lavender essential oil, and grapefruit essential oil in a specific ratio. It is said to have excellent deep facial repair effects, effectively repairing facial hormone damage caused by chemicals. While this method reduces evaporation, heat loss, and oxidation loss by attaching the essential oils to the mask, the mask itself still results in some loss and waste of the essential oils, and therefore cannot effectively avoid the problem of relatively low absorption of essential oils on the face.

[0005] For example, patent CN114426905A discloses an essential oil composite nanoemulsion and its preparation method. Through the interaction between essential oil, cordyceps polysaccharide, emulsifier, and water in a specific mass ratio, it can effectively improve the stability of essential oil, prolong the antioxidant activity of essential oil in the emulsion, and improve the dispersion effect of essential oil in water. Moreover, this nanoemulsion is a thermodynamically stable system, and it cannot be separated into layers by autoclaving or centrifugation, which is of great significance for prolonging the stability of essential oil.

[0006] Preparing essential oils into emulsions can effectively improve their stability, reduce loss, and enhance their effectiveness. However, when preparing emulsions from multiple blended essential oils, the differences in water solubility and other properties of the various essential oils can easily lead to emulsion separation and poor emulsification. Summary of the Invention

[0007] This invention provides a highly water-soluble nano-compound essential oil emulsion, its preparation method, and its application, to solve the technical problem that existing compound essential oil emulsions, while improving the stability of essential oils, suffer from poor emulsification effects due to the differences in the compound essential oils.

[0008] Rose essential oil is rich in α-pinene, which plays a role in repairing skin damage. Due to early-stage collagen deposition, α-pinene produces stress-resistant scars and accelerates wound contraction. Simultaneously, nerol, abundant in rose essential oil, can improve UVB-induced cellular oxidative damage by downregulating the expression levels of ROS, MDA, and SOD in UVB-induced oxidative damage cells, reducing the relative expression levels of MMP1, MMP3, and MMP9, as well as the expression level of MMP1 protein.

[0009] β-Caryophyllene in lavender essential oil is an ideal natural transdermal absorption enhancer, enabling compound essential oils to quickly penetrate the skin barrier and exert their effects during use. Lavender essential oil also contains abundant linalool and linalyl acetate, which can increase collagen expression and enhance the activity of proteins involved in tissue remodeling, thus playing a repairing role. Linalyl acetate can also inhibit TNF-α-induced cell adhesion molecules in endothelial cells by inhibiting NF-κB (nuclear factor protein, which regulates gene expression and plays an important role in cellular inflammation and immune responses), thereby reducing inflammatory responses and accelerating skin repair.

[0010] Frankincense essential oil contains abundant borneol acetate, which affects the phosphorylation of IKB and the production of IKKs by inhibiting the NF-κB signaling pathway. It can also inhibit the phosphorylation of ERK, JNK, and p38 through the MAPK signaling pathway, thereby downregulating pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6, upregulating IL-11, reducing NO production, exerting an anti-inflammatory effect, and accelerating the repair of the skin barrier.

[0011] Vetiver essential oil induces sebum production in human sebaceous cells, and its quality is improved through the production of specific antibacterial lipids. Furthermore, vetiver essential oil can restore the skin barrier, enhance lipid regeneration in reconstructed human epidermis and skin explants, stimulate lipid transport and epidermal keratinization, thus repairing the skin. Simultaneously, vetiver essential oil effectively inhibits the secretion of inflammatory factors such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), exhibiting good anti-inflammatory activity. It is an excellent skin healing agent that can promote skin tissue regeneration, achieving the purpose of repairing and purifying the skin.

[0012] The main chemical components of neroli essential oil are α-pinene, camphene, β-pinene, α-terpinene, nerol, nerol acetate, farnesol, esters, and indole. Neroli essential oil can enhance cell vitality, aid cell regeneration, and increase skin elasticity; it also whitens, moisturizes, fades dark spots, nourishes and reduces wrinkles, restoring a delicate appearance. It is suitable for dry, sensitive, and other problem skin types, especially for varicose veins, scars, and stretch marks; it can also be used to protect the skin during X-rays.

[0013] The main chemical components of lemon balm essential oil include citronellol, citronellol, geraniol, coriander oil, citral, citronellal, geraniol, and clove oil. Lemon balm essential oil can condition sensitive skin, normalize its metabolism, and give the skin a healthy glow.

[0014] In summary, the six single essential oils demonstrated their skin-repairing effects through different pathways, targets, and modes of action. The compound essential oil, composed of these six single essential oils, can form a good synergistic effect in the skin repair process, resulting in better skin repair efficacy.

[0015] The embodiments of the present invention are achieved through the following technical solutions:

[0016] A highly water-soluble nano-compound essential oil emulsion is composed of the following raw materials in parts by volume: 2-3 parts rose essential oil, 0.2-0.8 parts lavender essential oil, 1.5-2.5 parts frankincense essential oil, 0.5-1.5 parts vetiver essential oil, 1.5-2.5 parts neroli essential oil, 0.5-1.5 parts lemon balm essential oil, 18-24 parts glycerol fatty acid ester, 1-4 parts cationic emulsifier, and 50-70 parts dispersant solution.

[0017] This technical solution leverages the individual skin-repairing properties of rose, lavender, frankincense, vetiver, neroli, and lemon balm essential oils. Furthermore, these essential oils exhibit synergistic effects. For instance, neroli combined with frankincense can combat wrinkles; neroli combined with lavender activates skin regeneration, offering anti-scar and skin-softening benefits; neroli combined with rose activates and softens the skin, enhancing the absorption of the essential oil emulsion and providing some sleep-aiding effects; and rose combined with lemon balm produces a highly fragrant aroma with excellent mood-balancing properties. By rationally combining these essential oils to enhance their synergistic effects, and then processing them with cationic emulsifiers and dispersants to obtain a highly dispersed, water-soluble emulsion, the compound essential oil emulsion can effectively and rapidly act on the skin for repair.

[0018] Preferably, to further improve the effect of the compound essential oil emulsion, the compound essential oil emulsion is composed of the following raw materials in parts by volume: 2.2-2.8 parts rose essential oil, 0.4-0.6 parts lavender essential oil, 1.8-2.2 parts frankincense essential oil, 0.8-1.2 parts vetiver essential oil, 1.8-2.2 parts neroli essential oil, 0.8-1.2 parts lemon balm essential oil, 20-22 parts glycerol fatty acid ester, 2-3 parts cationic emulsifier, and 55-65 parts dispersant solution.

[0019] Preferably, the cationic emulsifier is at least one selected from hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, octadecyldimethylbenzylammonium chloride, and octadecyldimethylbenzylammonium bromide.

[0020] This technical solution uses cationic emulsifiers to prepare positively charged polymer emulsions, which can be used in high-temperature or low-temperature emulsion copolymerization reactions.

[0021] Preferably, the dispersant solution is composed of the following raw materials in parts by volume: 20 to 40 parts of at least one of hydroxypropyl-β-cyclodextrin and polymethacrylic acid and 60 to 80 parts of water.

[0022] This technical solution uses hydroxypropyl-β-cyclodextrin or polymethacrylic acid as both a dispersant and a film-forming agent, ensuring safety and eliminating risks. It increases the water solubility of essential oils, facilitates emulsion dispersion, and plays an auxiliary role in the formation of compound essential oil emulsions.

[0023] A method for preparing a highly water-soluble nano-compound essential oil emulsion includes the following steps:

[0024] S1: Preparation of compound essential oil: Add and mix rose essential oil, lavender essential oil, frankincense essential oil, vetiver essential oil, neroli essential oil and lemon balm essential oil to obtain compound essential oil;

[0025] S2: Preparation of the mixture: Mix 2-4 parts of the compound essential oil with 6-8 parts of glycerol fatty acid ester to obtain the mixture;

[0026] S3: Preparation of dispersant solution: Mix at least one of hydroxypropyl-β-cyclodextrin and polymethacrylic acid with water to obtain a dispersant solution;

[0027] S4: Preparation of compound essential oil emulsion: Mix 28-32 parts of the mixture, 1-3 parts of cationic emulsifier and 54-66 parts of dispersant solution and emulsify to obtain the compound essential oil emulsion.

[0028] Using this technical solution, the compatibility between the compound essential oils is good. First, they are mixed together to form a compound essential oil. Then, glycerol fatty acid esters are added as nonionic surfactants to pre-emulsify the compound essential oils to form a mixture. Then, a prepared dispersant solution and cationic emulsifier are added to improve the water solubility of the compound essential oils and form a positively charged polymer emulsion with nano-coating. This improves the water solubility of the compound essential oil emulsion and enhances its absorption capacity and efficiency by the skin, allowing it to be effectively absorbed and exert its effects.

[0029] Preferably, in step S2, the glycerol fatty acid ester is added dropwise to the compound essential oil under a stirring condition of 300-500 r / min, and the addition is completed within 5-10 min. After the addition is completed, stirring is continued for 30-45 min to obtain the mixture.

[0030] Using this technical solution, when pre-emulsifying the mixture, glycerol fatty acid esters are slowly added under certain stirring to form a pre-emulsified mixture with a low degree of emulsification.

[0031] Preferably, in step S4, under stirring conditions of 500-1000 r / min, the cationic emulsifier is first slowly added to the mixture, and the addition is completed within 12 min. After the addition is completed, stirring is continued for 30-45 min before adding the dispersant solution.

[0032] Preferably, in step S4, after the cationic emulsifier is added and stirred, the dispersant solution is added dropwise at a speed of 1500-3000 r / min and a temperature of 2040°C, and the addition is completed within 5-10 minutes. After the addition is completed, the composite essential oil emulsion is obtained by high-speed emulsification.

[0033] When emulsifying the mixture using this technical solution, a cationic emulsifier is first slowly added under stirring. After stirring for a period of time, a dispersant solution is then added to form a system-dispersed compound essential oil solution.

[0034] Preferably, the rose essential oil, lavender essential oil, frankincense essential oil, vetiver essential oil, neroli essential oil, and lemon balm essential oil are extracted and separated by steam distillation.

[0035] Using this technical solution, the corresponding plant essential oils are extracted by conventional distillation. The preparation method is simple and the essential oils are relatively clean.

[0036] An application of a highly water-soluble nano-compound essential oil emulsion, characterized in that: the compound essential oil emulsion is used for skin repair.

[0037] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0038] 1. The single essential oils of this invention, while exerting the effects of their individual components, can form a synergistic effect with other essential oils. By rationally combining the single essential oils, their synergistic effect can be enhanced.

[0039] 2. This invention prepares a highly dispersed, water-soluble emulsion from compound essential oils using a cationic emulsifier and dispersant solution, enabling the compound essential oil emulsion to effectively and quickly act on skin repair.

[0040] 3. The preparation process of the compound essential oil emulsion of the present invention is divided into two processes: pre-emulsification with nonionic emulsifier and emulsification with cationic emulsifier, forming a dispersed emulsion system and forming a positively charged polymer emulsion with nano-coating, which improves the stability of the compound emulsion and ensures that it can act on the skin quickly. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the process flow for preparing the highly water-soluble nano-compound essential oil emulsion provided in Example 1 of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] Example 1

[0046] A method for preparing a highly water-soluble nano-compound essential oil emulsion includes the following steps:

[0047] S1: Preparation of compound essential oil: Add 2.5 parts of rose essential oil, 0.5 parts of lavender essential oil, 2 parts of frankincense essential oil, 1 part of vetiver essential oil, 2 parts of neroli essential oil and 1 part of lemon balm essential oil and mix well to obtain compound essential oil;

[0048] S2: Preparation of the mixture: Mix 3 parts of the compound essential oil with 7 parts of glycerol fatty acid ester to obtain the mixture;

[0049] S3: Preparation of dispersant solution: Mix 30 parts of hydroxypropyl-β-cyclodextrin and 70 parts of water to obtain a dispersant solution;

[0050] S4: Preparation of compound essential oil emulsion: Mix 30 parts of the mixture, 2 parts of hexadecyltrimethyl quaternary ammonium bromide and 60 parts of dispersant solution and emulsify to obtain the compound essential oil emulsion.

[0051] In this embodiment, in step S2, the glycerol fatty acid ester is added dropwise to the compound essential oil under a stirring condition of 400 r / min, and the addition is completed in about 7 minutes. After the addition is completed, stirring is continued for 40 minutes to obtain the mixture.

[0052] In this embodiment, in step S4, under a stirring condition of 750 r / min, the hexadecyltrimethyl quaternary ammonium bromide is first slowly added to the mixture, and the addition is completed within 2 min. After the addition is completed, stirring is continued for 40 min before the dispersant solution is added.

[0053] In this embodiment, in step S4, after the cetyltrimethyl quaternary ammonium bromide is added and stirred, the dispersant solution is added dropwise at a speed of 2000 r / min and a temperature of 30°C, and the addition is completed within 10 minutes. After the addition is completed, the composite essential oil emulsion is obtained by high-speed emulsification.

[0054] In this embodiment, the rose essential oil, lavender essential oil, frankincense essential oil, vetiver essential oil, neroli essential oil, and lemon balm essential oil were extracted and separated by steam distillation.

[0055] Example 2

[0056] The difference between this embodiment and Embodiment 1 is only that in step S1:

[0057] Preparation of compound essential oil: Add 3 parts rose essential oil, 0.5 parts lavender essential oil, 2 parts frankincense essential oil, 1 part vetiver essential oil, 1.5 parts neroli essential oil and 1 part lemon balm essential oil and mix well to obtain compound essential oil.

[0058] Example 3

[0059] The difference between this embodiment and Embodiment 1 is only that in step S1:

[0060] Preparation of compound essential oil: Add 2 parts rose essential oil, 0.5 parts lavender essential oil, 2 parts frankincense essential oil, 1 part vetiver essential oil, 2.5 parts neroli essential oil and 1 part lemon balm essential oil and mix well to obtain compound essential oil.

[0061] Comparative Example 1

[0062] The only difference between this comparative example and Example 1 is that, in step S1:

[0063] Preparation of compound essential oil: Add 2.5 parts of rose essential oil, 1 part of lavender essential oil, 2.5 parts of frankincense essential oil, 1.5 parts of vetiver essential oil and 1.5 parts of lemon balm essential oil and mix well to obtain compound essential oil.

[0064] Comparative Example 2

[0065] The only difference between this comparative example and Example 1 is that, in step S1:

[0066] Preparation of compound essential oil: Add 1 part lavender essential oil, 2.5 parts frankincense essential oil, 1.5 parts vetiver essential oil, 2.5 parts neroli essential oil and 1.5 parts lemon balm essential oil and mix well to obtain compound essential oil.

[0067] Comparative Example 3

[0068] The only difference between this comparative example and Example 1 is that emulsification is performed directly without step S2: preparation of the mixture.

[0069] Comparative Example 4

[0070] The only difference between this comparative example and Example 1 is that, in step S4, a cationic emulsifier is not used; instead, glycerol fatty acid esters are still used to further emulsify the mixture.

[0071] The relevant data of the test schemes described in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1:

[0072] Table 1. Volume content of relevant essential oil components in Examples 1-3 and Comparative Examples 1-2

[0073]

[0074] Water solubility test of compound essential oil emulsion:

[0075] According to GB / T 6324.1-2004 Test Methods for Organic Chemical Products Part 1: Method for Testing the Miscibility of Liquid Organic Chemical Products in Water, the solubility of compound essential oils and compound essential oil emulsions in the test examples and comparative examples were determined.

[0076] The specific method is as follows: Measure a certain volume of sample according to a predetermined ratio and inject it into a clean, dry colorimetric tube. Slowly add water to the 100mL mark, tighten the stopper, shake thoroughly, and let stand until all air bubbles disappear. Place the colorimetric tube in a constant temperature device at (20±1)℃ for 30 minutes. Add 100mL of water to another 100mL colorimetric tube of the same material as a blank solution. After 30 minutes, remove the colorimetric tube from the constant temperature device, wipe the outer wall of the colorimetric tube dry, and axially compare the sample-water solution and the blank solution against a black background. The experimental results are shown in Table 2.

[0077] Table 2. Clarity Test of Compound Essential Oils and Compound Essential Oil Emulsions in Examples 1 and Comparative Examples 3-4

[0078]

[0079] Complex essential oils are almost insoluble in water, but the complex essential oil emulsion prepared by encapsulation and emulsification with hydroxypropyl-β-cyclodextrin showed significantly improved solubility in water after testing.

[0080] The compound essential oil emulsions of Examples 1-3 and Comparative Examples 1-2 were formulated into compositions, the components of which are shown in Table 3:

[0081] Table 3. Components of the compound essential oil emulsions formulated in Examples 1-3 and Comparative Examples 1-2 as compositions

[0082]

[0083] Repair efficacy test of compound essential oil emulsion composition:

[0084] This invention uses a human fibroblast migration ability test as a model to evaluate the repair efficacy of compound essential oil emulsions.

[0085] Fibroblasts are mesodermal cells widely found in loose connective tissue. They secrete extracellular matrix components such as procollagen, fibronectin, and collagenase, and can migrate to wounds to proliferate during wound healing. Cell migration, also known as cell crawling, refers to the movement of cells after receiving migration signals or sensing gradients of certain substances. The cell migration ability test, also known as the scratch test, involves artificially drawing a blank area, called a "scratch," on a monolayer of cells when they have swelled and fused. Cells at the edge of the scratch gradually enter the blank area, healing the "scratch," thus mimicking the process of cell migration in vivo to some extent. Cell migration in vivo includes the healing of micro-wounds, which is similar to the repairing effects of cosmetics that smooth skin texture and promote skin damage healing. Furthermore, fibroblasts are the main cellular component of loose connective tissue in the dermis, and the results of human fibroblast models have some reference value for in vivo effects. Therefore, using human fibroblasts in a careful cell migration test can evaluate the repairing efficacy of cosmetics.

[0086] Test method:

[0087] (1) Plate preparation: Prepare a 24-well cell culture plate and mark it by drawing a horizontal line on the back with a marker. Select well-grown P7 generation human fibroblasts, digest them, dilute them to an appropriate concentration, add them to the well plate, and incubate them in an incubator for about 24 hours.

[0088] (2) Sample addition: Check the iron wall of the cells. Once the cell plating rate reaches 80-90%, sample addition can proceed. Aspirate the original culture medium and add the test substance. Set up a blank control group, a positive control group, and a sample group, and add samples prepared with serum-free culture medium, 10% serum culture medium, and serum-free culture medium, respectively. After sample addition, place the cell culture plate in an incubator and incubate for about 24 hours.

[0089] (3) Scratching: When the cell deposition rate reaches about 90%, use a 1mL pipette tip to scratch the bottom of the plate, with the pipette tip perpendicular to the marker mark and applying even pressure. The observation point is located above or below the intersection of the scratch and the marker mark. There should be more than 4 observation points per well. After scratching, gently wash with PBS 2-3 times to remove floating cells.

[0090] (4) Photography: Immediately after the scratch is completed, take a 0-hour photograph to record the original scratch size. After taking the photograph, remove the PBS and add serum-free culture medium to each well, and incubate in an incubator for about 24 hours. After incubation, take a 24-hour photograph at the same location using the same magnification objective lens as the observation point taken at 0 hours to record the scratch repair status.

[0091] (5) Process the scratch images using ImageJ software to obtain the area values. Calculate the cell migration rate using the following formula:

[0092]

[0093] The test results are shown in Table 4:

[0094] Table 4. Effects of compound essential oil emulsion compositions on human fibroblast migration rate.

[0095] sample Migration rate (%) Mean ± SD Blank group 0.2±0.021 control group 4±0.019 Example 1 29.21±0.047 Example 2 27.32±0.031 Example 3 28.52±0.059 Comparative Example 1 18.5±0.011 Comparative Example 2 17.27±0.019

[0096] The composition prepared with different amounts of the best-performing Example 1 was tested again, and the test results are shown in Table 5:

[0097] Table 5. Effect of different amounts of compound essential oil emulsion added in Example 1 on human fibroblast migration rate.

[0098] Amount added (w%) Migration rate (%) Mean ± SD 0 6±0.031 1 17.03±0.042 2 24.84±0.029 4 29.21±0.033 8 29.04±0.017

[0099] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A highly water-soluble nano-compound essential oil emulsion, characterized in that: It is composed of the following raw materials in parts by volume: 2-3 parts rose essential oil, 0.2-0.8 parts lavender essential oil, 1.5-2.5 parts frankincense essential oil, 0.5-1.5 parts vetiver essential oil, 1.5-2.5 parts neroli essential oil, 0.5-1.5 parts lemon balm essential oil, 18-24 parts glycerol fatty acid ester, 1-4 parts cationic emulsifier, and 50-70 parts dispersant solution; The cationic emulsifier is hexadecyltrimethylquaternary ammonium bromide; The preparation method of the highly water-soluble nano-compound essential oil emulsion includes the following steps: S1: Preparation of compound essential oil: Add and mix rose essential oil, lavender essential oil, frankincense essential oil, vetiver essential oil, neroli essential oil and lemon balm essential oil to obtain compound essential oil; S2: Preparation of the mixture: Mix 2-4 parts of the compound essential oil with 6-8 parts of glycerol fatty acid ester to obtain the mixture; S3: Preparation of dispersant solution: Mix at least one of hydroxypropyl-β-cyclodextrin and polymethacrylic acid with water to obtain a dispersant solution; S4: Preparation of compound essential oil emulsion: Mix 28-32 parts of the mixture, 1-3 parts of cationic emulsifier and 54-66 parts of dispersant solution and emulsify to obtain compound essential oil emulsion.

2. The highly water-soluble nano-compound essential oil emulsion according to claim 1, characterized in that: It is composed of the following raw materials in parts by volume: 2.2-2.8 parts rose essential oil, 0.4-0.6 parts lavender essential oil, 1.8-2.2 parts frankincense essential oil, 0.8-1.2 parts vetiver essential oil, 1.8-2.2 parts neroli essential oil, 0.8-1.2 parts lemon balm essential oil, 20-22 parts glycerol fatty acid ester, 2-3 parts cationic emulsifier, and 55-65 parts dispersant solution.

3. A highly water-soluble nano-compound essential oil emulsion according to claim 1 or 2, characterized in that: The dispersant solution is composed of the following raw materials in parts by volume: 20 to 40 parts of at least one of hydroxypropyl-β-cyclodextrin and polymethacrylic acid and 60 to 80 parts of water.

4. The highly water-soluble nano-compound essential oil emulsion according to claim 1, characterized in that: In step S2, the glycerol fatty acid ester is added dropwise to the compound essential oil under stirring conditions of 300-500 r / min, and the mixture is stirred at 5... The addition should be completed within 10 minutes. After the addition is finished, continue stirring for 30 to 45 minutes to obtain the mixture.

5. A highly water-soluble nano-compound essential oil emulsion according to claim 1 or 4, characterized in that: In step S4, under stirring conditions of 500-1000 r / min, the cationic emulsifier is first added to the mixture and added within 1-2 min. After the addition is completed, stirring is continued for 30-45 min before adding the dispersant solution.

6. The highly water-soluble nano-compound essential oil emulsion according to claim 5, characterized in that: In step S4, after the cationic emulsifier is added and stirring is complete, the dispersant solution is continued to be added dropwise at a speed of 1500–3000 r / min and a temperature of 20–40°C, for a period of 5 minutes. The dripping was completed within 10 minutes. After the dripping was finished, high-speed emulsification was used to obtain the compound essential oil emulsion.

7. A highly water-soluble nano-compound essential oil emulsion according to any one of claims 1 and 4, characterized in that: The rose essential oil, lavender essential oil, frankincense essential oil, vetiver essential oil, neroli essential oil, and lemon balm essential oil were extracted and separated by steam distillation.

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