An essential oil nanocarrier based on wild soybean extract, its preparation method and application

Abstract

This invention belongs to the field of skincare technology, specifically relating to an essential oil nanocarrier based on wild soybean extract, its preparation method, and its application. This invention uses hydroxypropyl-β-cyclodextrin as the wall material, a mixture of polysorbate emulsifiers and wild soybean extract as a composite emulsifier, and essential oil as the content, overcoming the shortcomings of poor stability and low solubility of essential oils. This results in an essential oil nanocarrier with small particle size, good high and low temperature stability, high transparency, low irritation, and significant functional effects. This essential oil nanocarrier can be widely used in skincare products as a fragrance agent or moisturizing and repairing active ingredient. Furthermore, since it is a clear and transparent liquid, it can also be used in transparent aqueous cosmetics.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of skin care products, and particularly relates to an essential oil nano-delivery carrier based on wild soybean extract as well as a preparation method and application thereof. BACKGROUND

[0002] Essential oils are natural oily substances composed of terpenes, phenols, aldehydes, ethers and other bioactive ingredients, usually in liquid form, and have the effects of antibacterial, antioxidant and anticancer. The encapsulation of essential oils is the key to solving the problems of easy evaporation, unstable chemical properties and low water solubility. The essential oil delivery carrier formed by encapsulating essential oils has the characteristics of good dispersibility, high stability and excellent bioactivity. The smaller the particle size of the delivery carrier, the better it can overcome its own gravity by Brownian motion to disperse uniformly, achieve a certain kinetic stability, and the delivery efficiency of the essential oil content is also higher. Therefore, nano-sized essential oil delivery carriers have broad prospects in various application fields.

[0003] Hydroxypropyl-beta-cyclodextrin is a modified product of beta-cyclodextrin, which has both the cavity of beta-cyclodextrin and improved water solubility. It has the characteristics of antioxidant decomposition, anti-volatility, and odor adsorption. Currently, the delivery carriers prepared by cyclodextrin and cyclodextrin derivatives studied have mostly powder states, such as the hydroxypropyl-beta-cyclodextrin-apple fragrance encapsulate obtained in patent CN113262743A is in powder state. The powder form of encapsulate needs to be post-processed by distillation equipment, freeze-drying or spray drying equipment in the preparation process, which is a waste of resources. A small part is in liquid state, but most of the liquid feed liquids are semi-transparent or opaque in appearance, with a particle size of microns, poor stability, and are prone to low-temperature precipitation or high-temperature transparency instability in extreme environments, especially when used in cosmetic water products, which affects their transparency and stability. A very small number of nano-delivery carriers in clear and transparent liquid state usually need to be dissolved by organic reagents or prepared and then self-assembled after standing, which is time-consuming and laborious in subsequent elution and drying and storage processes, resulting in a certain waste of resources.

[0004] Currently, there are clear and transparent liquid state nano delivery carriers prepared by cyclodextrin and cyclodextrin derivatives. If not achieved by adding organic reagents or long-term self-assembly process, high content of emulsifier is usually added to form a thermodynamically stable system. However, the use of a large amount of emulsifier is not conducive to skin care and may cause certain irritation, so the amount of emulsifier added is usually as small as possible under the premise of ensuring system stability. In fact, the adsorption strength of molecules adsorbed on the O / W oil-water interface and the level of intermolecular interaction are important factors affecting the overall kinetic stability of the nano delivery carrier and the interfacial rheological response. Nonionic emulsifiers such as polysorbate (such as polysorbate-20, polysorbate-60, polysorbate-80, etc.) are commonly used emulsifiers for preparing nano delivery carriers with cyclodextrin and cyclodextrin derivatives as wall materials. However, the high surface activity and spatial interaction of such emulsifiers on the O / W oil-water interface will weaken over time, and the interface oil droplets will gradually accelerate aggregation, eventually leading to liquid oil-water layering of the nano delivery carrier.

[0005] Currently, the stability of the encapsulated delivery carrier depends largely on the wall material composition and the feeding speed, especially the feeding speed. Proper feeding speed can form fine emulsions and monodisperse emulsions to prevent oil droplets from coalescing during preparation. Through high-energy homogenization and low-energy spontaneous emulsification, a nano delivery carrier with kinetic and thermodynamic stability is formed.

[0006] In the current research on nano delivery carriers, most of them are used as delivery carriers to achieve the function of transferring contents. For example, patent CN115381732A only provides a preparation method for encapsulating retinol with hydroxypropyl cyclodextrin. The wall material of the delivery carrier in the document does not have skin care efficacy and cannot synergistically act with the contents in the cosmetic system. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a nano delivery carrier for essential oil based on wild soybean extract. The essential oil nano delivery carrier is prepared by encapsulating essential oil with hydroxypropyl-β-cyclodextrin, using a combination emulsifier of nonionic emulsifier polysorbate and amphoteric emulsifier wild soybean extract (the main effective ingredient is soybean lysophosphatidylcholine). The obtained essential oil nano delivery carrier has the advantages of small particle size, good stability, high transparency, low irritation, and significant efficacy. In addition, the present application also provides a preparation method for the above-mentioned essential oil nano delivery carrier based on wild soybean extract, which has the advantages of simple operation, high repeatability, time and labor saving, and strong stability. Finally, the essential oil nano delivery carrier of the present application can be widely used as a fragrance or a moisturizing and repairing active substance in various skin care products, especially in transparent water-based products.

[0008] The technical scheme of the present application is as follows:

[0009] In a first aspect, the present invention provides an essential oil nano-delivery carrier based on wild soybean extract, comprising the following components: essential oil, hydroxypropyl-β-cyclodextrin, polysorbate emulsifier, wild soybean extract, and water.

[0010] Preferably, the hydroxypropyl-β-cyclodextrin has a mass percentage of 4.0–9.0%; the essential oil has a mass percentage of 0.001–2.5%, more preferably 1.0–2.5%; the polysorbate emulsifier has a mass percentage of 1.5–7.0%; the wild soybean extract has a mass percentage of 0.2–2.0%, and the balance is deionized water.

[0011] In this invention, the essential oil nano-delivery carrier is a pale yellow to deep yellow transparent liquid. Under a transmission electron microscope, its microstructure appears as a circle or ellipse with a particle size of 10-30 nm.

[0012] This invention utilizes hydroxypropyl-β-cyclodextrin as the wall material, a mixture of polysorbate emulsifiers and wild soybean extract as a composite emulsifier, and essential oils as the content, overcoming the shortcomings of poor stability and low solubility of essential oils. This results in the preparation of an essential oil nano-delivery carrier with small particle size, good high and low temperature stability, high transparency, low irritation, and significant functional effects. The essential oil nano-delivery carrier of this invention is a clear and transparent liquid, ensuring that its preparation process does not require organic reagents as solvents or prolonged static self-assembly. It can rapidly achieve a clear, transparent, and stable system within 24 hours after preparation, and can be widely used as a fragrance or moisturizing and repairing active ingredient in skincare products, especially in transparent aqueous cosmetic formulations. It can maintain a clear, transparent, and stable state for a long time under high temperature, low temperature, and high and low temperature cycling conditions. This may be attributed to the fact that the stability of the nano-delivery carrier in the first 24 hours depends on the type and concentration of the emulsifier, and that the soybean lecithin contained in wild soybean extract easily forms a buffer elastic layer with low surface tension at the O / W interface. Meanwhile, another polysorbate emulsifier in the system can undergo orderly self-assembly with hydroxypropyl-β-cyclodextrin, building a "channel" between the host hydroxypropyl-β-cyclodextrin and the guest essential oil molecule, forming a stable three-phase system of host, guest, and emulsifier, promoting the rapid entry of the guest essential oil molecule into the hydrophobic cavity of the host, and finally forming a clear, transparent and stable nano-delivery carrier.

[0013] One of the emulsifiers in this invention, wild soybean extract, is of natural origin, green, safe, mild, and non-irritating. In existing stable systems with the same amount of essential oil added, compared to using polysorbate emulsifiers alone, a system using wild soybean extract in combination with polysorbate emulsifiers can reduce the total amount of emulsifier added by approximately 21%, thus lowering the risk of irritation caused by emulsifiers.

[0014] Furthermore, compared with other common emulsifiers and polysorbate emulsifier blends, the essential oil nano-delivery carrier is clear, transparent, and stable. This may be attributed to the fact that anionic emulsifiers such as potassium cetyl phosphate, cationic emulsifiers such as hexadecyltrimethylammonium chloride, nonionic emulsifiers such as inulin lauryl carbamate, and zwitterionic emulsifiers such as cocamidopropyl hydroxysulfobetaine cannot form a buffer elastic layer with low surface tension at the O / W interface like wild soybean extract. At the same time, they cannot promote the orderly self-assembly of polysorbate emulsifiers and hydroxypropyl-β-cyclodextrin, ultimately failing to achieve the ideal effect of maintaining long-term stability.

[0015] Preferably, the essential oils include one or more of the following: lavender, rose, rose geranium, Damask rose, sandalwood, bergamot, patchouli, clary sage, whole ylang-ylang, sweet orange, pink grapefruit, peppermint, organic juniper berry, Atlantic cedar, (bitter) orange blossom, lemongrass, lemon, tea tree, jasmine, rosemary, frankincense, myrrh, thyme, vetiver, benzoin, galbanum, Scots pine, cypress, holly, eucalyptus, oregano, ginger, cinnamon, bay leaf, nutmeg, fennel, clove, eucalyptus, and Roman chamomile.

[0016] Preferably, the polysorbate emulsifier is selected from one or more of polysorbate-20, polysorbate-60 and polysorbate-80.

[0017] Preferably, the essential oil nanodelivery carrier further includes a preservative.

[0018] More preferably, the preservative includes one or more of the following: methylparaben, sodium benzoate, chlorophenoxyethanol, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, phenoxyethanol, p-hydroxyacetophenone, 1,2-hexanediol, 1,3-propanediol, propylene glycol, 1,2-pentanediol, pentanediol, caprylyl glycol, ethylhexylglycerol, methylisothiazolinone, methylchloroisothiazolinone, magnesium nitrate, magnesium chloride, benzalkonium bromide, benzalkonium chloride, glutaraldehyde, isopentyl glycol, o-cymene-5-ol, bis(hydroxymethyl)imidazolidinyl urea, iodopropynyl butylcarbamate, sodium hydroxymethylglycinate, DMDM ​​hydantoin, sorbic acid and its salts, benzoic acid and its salts and esters, and benzyl alcohol.

[0019] More preferably, the preservative includes methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, and 1,2-hexanediol.

[0020] More preferably, the preservative has a mass percentage of 0.005–1.2%.

[0021] Secondly, the present invention provides a method for preparing an essential oil nanocarrier based on wild soybean extract, comprising the following steps:

[0022] (a) Mix hydroxypropyl-β-cyclodextrin with water and stir until completely dissolved to obtain solution a;

[0023] (b) Mix the polysorbate emulsifier with wild soybean extract and stir until the mixed emulsifier is clear and transparent to obtain solution b;

[0024] (c) Add the essential oil dropwise to solution a at a rate of 0.6-0.8 mL per minute while stirring, to obtain solution c;

[0025] (d) Add solution b to solution c at a rate of 3.0-5.0 mL per minute while stirring, to obtain solution d;

[0026] (e) The solution d is subjected to ultrasonic treatment, with the ultrasonic power controlled at 400-500W, the ultrasonic time at 5-10min, the ultrasonic on time at 2.0-3.0s, and the ultrasonic off time at 2.0-3.0s, to prepare the essential oil nano-delivery carrier.

[0027] Preferably, in step (a), the stirring speed is 400-600 rpm and the stirring time is 5-10 min.

[0028] Preferably, in step (b), the stirring speed is 100-200 rpm and the stirring time is 5-10 min.

[0029] Preferably, in step (c), the stirring speed is 400-600 rpm and the stirring time is 20-30 min.

[0030] Preferably, in step (d), the stirring speed is 400-600 rpm and the stirring time is 60-120 min.

[0031] Preferably, in step (e), a preservative is added after the ultrasonic treatment is completed.

[0032] In terms of the process of this invention, the ratio of feed liquid to liquid, the feed rate, and the ultrasonic treatment parameters all affect the transparency of the essential oil nano-delivery carrier. Among them, the feed rate is one of the most important factors. Controlling the droplet acceleration can ensure that the oil phase is completely dispersed when it first enters the system, avoid the merging and aggregation of the next oil phase droplet, which would reduce the contact area between the two phases and increase the emulsification efficiency.

[0033] The present invention prepares an essential oil nanocarrier based on wild soybean extract through the above-mentioned ultrasonic treatment. The nanocarrier has the characteristics of small particle size, strong stability, high transparency, simple operation, high repeatability, and time and labor saving.

[0034] Thirdly, the present invention provides the application of the above-mentioned essential oil nano-delivery carrier based on wild soybean extract as a fragrance or moisturizing and repairing active ingredient in the preparation of skin care products. The essential oil nano-delivery carrier has the effects of moisturizing, repairing the skin barrier, promoting skin penetration and slow-release of fragrance. In terms of repair, wild soybean extract and essential oil have a synergistic effect.

[0035] Fourthly, the present invention provides the application of the above-mentioned essential oil nano-delivery carrier based on wild soybean extract in the preparation of transparent aqueous cosmetics.

[0036] Beneficial effects:

[0037] 1. This invention prepares an essential oil nano-delivery carrier based on wild soybean extract by strictly limiting at least three aspects: the type of emulsifier, the ratio of polysorbate emulsifier to wild soybean extract, and the preparation process. This essential oil nano-delivery carrier has the characteristics of small particle size, good high and low temperature stability, high transparency, low irritation, and significant functional effects. It can be widely used as a fragrance or moisturizing and repairing active ingredient in skin care products.

[0038] 2. The essential oil nano-delivery carrier based on wild soybean extract provided by this invention is a clear and transparent liquid and can also be applied to transparent aqueous cosmetics. Attached Figure Description

[0039] Figure 1 Transmission electron microscopy image of an essential oil nanoparticle delivery carrier.

[0040] Figure 2 The surface tension scatter plot and droplet area curve of the essential oil nano-delivery carrier in Example 1 / Comparative Example 4 are shown.

[0041] Figure 3 The thermogravimetric analysis curves (solid line) and differential thermogravimetric analysis curves (dashed line) of the essential oil nano-delivery carriers in Example 2 / Comparative Example 1 are shown.

[0042] Figure 4 The thermogravimetric analysis curves (solid line) and micro-thermogravimetric analysis curves (dashed line) of essential oil nano-delivery carriers and lavender essential oil in Examples 1 / 2 / 3 are shown.

[0043] Figure 5The bar chart shows the relative IOD / area average of isolated skin tissue under different test solutions. Compared with the control group, significance is indicated by #: 0.01≤P<0.05 is indicated by #, 0.001≤P<0.01 by ##, 0.0001≤P<0.001 by ###, and P<0.0001 by ####. Compared with the negative control group, significance is indicated by *: 0.01≤P<0.05 is indicated by *, 0.001≤P<0.01 by **, 0.0001≤P<0.001 by ***, and P<0.0001 by ****. Detailed Implementation

[0044] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the raw materials involved in the embodiments are all commercially available products.

[0045] Technical solution overview:

[0046] An essential oil nanocarrier based on wild soybean extract comprises the following components: essential oil, hydroxypropyl-β-cyclodextrin, polysorbate emulsifier, wild soybean extract, preservative, and water. Preferably, the hydroxypropyl-β-cyclodextrin comprises 4.0–9.0% by mass; the essential oil comprises 0.001–2.5% by mass, preferably 1.0–2.5%; the polysorbate emulsifier comprises 1.5–7.0% by mass, the wild soybean extract comprises 0.2–2.0% by mass, the preservative comprises 0.005–1.2% by mass, and the balance is deionized water.

[0047] Preferably, the essential oils include one or more of the following: lavender, rose, rose geranium, Damask rose, sandalwood, bergamot, patchouli, clary sage, whole ylang-ylang, sweet orange, pink grapefruit, peppermint, organic juniper berry, Atlantic cedar, (bitter) orange blossom, lemongrass, lemon, tea tree, jasmine, rosemary, frankincense, myrrh, thyme, vetiver, benzoin, galbanum, Scots pine, cypress, holly, eucalyptus, oregano, ginger, cinnamon, bay leaf, nutmeg, fennel, clove, eucalyptus, and Roman chamomile.

[0048] Preferably, the polysorbate emulsifier is selected from one or more of polysorbate-20, polysorbate-60 and polysorbate-80.

[0049] The preservatives include one or more of the following: methylparaben, sodium benzoate, chlorophenoxyethanol, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, phenoxyethanol, p-hydroxyacetophenone, 1,2-hexanediol, 1,3-propanediol, propylene glycol, 1,2-pentanediol, pentanediol, caprylyl glycol, ethylhexylglycerol, methylisothiazolinone, methylchloroisothiazolinone, magnesium nitrate, magnesium chloride, benzalkonium bromide, benzalkonium chloride, glutaraldehyde, isopentyl glycol, o-cymene-5-ol, bis(hydroxymethyl)imidazolidinyl urea, iodopropynyl butylcarbamate, sodium hydroxymethylglycinate, DMDM ​​hydantoin, sorbic acid and its salts, benzoic acid and its salts and esters, and benzyl alcohol.

[0050] Preferably, the preservatives include methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, and 1,2-hexanediol.

[0051] Among them: rose essential oil was sourced from Yaqi Industrial (Shanghai) Co., Ltd., lavender essential oil from Xinjiang Yiparhan Fragrance Co., Ltd., hydroxypropyl-β-cyclodextrin from Shanghai Maclean Biochemical Technology Co., Ltd., polysorbate-20, polysorbate-60, and polysorbate-80 from Beijing Solarbio Technology Co., Ltd., and wild soybean extract from Lucas Meyer Cosmetics (the active ingredient is 20% wild soybean (GLYCIN E SOJA) seed extract, and the other solvent is glycerin; all examples and comparative examples are set according to the content of the active ingredient).

[0052] A method for preparing an essential oil nanocarrier based on wild soybean extract includes the following steps:

[0053] (a) Add hydroxypropyl-β-cyclodextrin to deionized water and stir until completely dissolved. The stirring speed is 400-600 rpm and the stirring time is 5-10 min to obtain solution a;

[0054] (b) Mix nonionic emulsifier polysorbate with amphoteric emulsifier soybean extract, stir and disperse at a stirring speed of 100-200 rpm for 5-10 min, and the mixed emulsifier is clear and transparent to obtain solution b;

[0055] (c) Add the essential oil dropwise to solution a at a rate of 0.6-0.8 mL per minute while stirring at a speed of 400-600 rpm for 20-30 minutes to obtain solution c;

[0056] (d) Add solution b to solution c at a rate of 3.0-5.0 mL per minute while stirring at a speed of 400-600 rpm for 60-120 min to obtain solution d;

[0057] (e) The solution d was ultrasonically treated by an ultrasonic cell disruptor. The ultrasonic power was controlled at 400-500W and the ultrasonic time was 5-10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0058] Example 1:

[0059] An essential oil nanocarrier based on wild soybean extract comprises, by weight percentage: 1.3% lavender essential oil, 4.6% hydroxypropyl-β-cyclodextrin, 1.7% polysorbate-80, 1.2% wild soybean extract, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0060] The preparation method of the essential oil nanocarrier based on wild soybean extract includes the following steps:

[0061] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-80, wild soybean extract, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0062] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 400 rpm until completely dissolved for 5 minutes to obtain solution a;

[0063] C. Mix polysorbate-80 with wild soybean extract and stir at 100 rpm until the mixed emulsion is clear and transparent. The stirring time is 5 min to obtain solution b.

[0064] D. Add lavender essential oil dropwise to solution a at a rate of 0.6 mL per minute while stirring at a speed of 600 rpm for 30 minutes to obtain solution c.

[0065] E. Add solution b to solution c at a rate of 4.0 mL per minute while stirring at 400 rpm for 120 minutes to obtain solution d.

[0066] F. The solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 500W and the ultrasonic time was 10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0067] Example 2:

[0068] An essential oil nanocarrier based on wild soybean extract comprises, by weight percentage: 2.2% lavender essential oil, 7.7% hydroxypropyl-β-cyclodextrin, 6.6% polysorbate-60, 1.3% wild soybean extract, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0069] The preparation method of the essential oil nanocarrier based on wild soybean extract includes the following steps:

[0070] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-60, wild soybean extract, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0071] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 500 rpm until completely dissolved for 7 minutes to obtain solution a;

[0072] C. Mix polysorbate-60 with wild soybean extract and stir at 150 rpm until the mixed emulsion is clear and transparent. The stirring time is 8 minutes to obtain solution b.

[0073] D. Add lavender essential oil dropwise to solution a at a rate of 0.7 mL per minute while stirring at a speed of 500 rpm for 25 minutes to obtain solution c.

[0074] E. Add solution b to solution c at a rate of 3.0 mL per minute while stirring at 600 rpm for 80 minutes to obtain solution d.

[0075] F. The solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 450W and the ultrasonic time was 10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0076] Example 3:

[0077] An essential oil nanocarrier based on wild soybean extract comprises, by weight percentage: 1.6% lavender essential oil, 4.4% hydroxypropyl-β-cyclodextrin, 5.9% polysorbate-20, 0.3% wild soybean extract, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0078] The preparation method of the essential oil nanocarrier based on wild soybean extract includes the following steps:

[0079] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-20, wild soybean extract, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0080] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 600 rpm until completely dissolved for 10 min to obtain solution a;

[0081] C. Mix polysorbate-20 with wild soybean extract and stir at 200 rpm until the emulsion mixture is clear and transparent. Stir for 10 minutes to obtain solution b.

[0082] D. Add lavender essential oil dropwise to solution a at a rate of 0.8 mL per minute while stirring at a speed of 400 rpm for 20 minutes to obtain solution c.

[0083] E. Add solution b to solution c at a rate of 4.0 mL per minute while stirring at 500 rpm for 100 min to obtain solution d.

[0084] F. The solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 400W and the ultrasonic time was 10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0085] Example 4:

[0086] An essential oil nanocarrier based on wild soybean extract comprises, by weight percentage: 1.6% rose essential oil, 4.4% hydroxypropyl-β-cyclodextrin, 5.9% polysorbate-20, 0.3% wild soybean extract, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0087] The preparation method of the essential oil nanocarrier based on wild soybean extract includes the following steps:

[0088] A. Weigh out the following ingredients according to the formula: rose essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-20, wild soybean extract, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0089] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 600 rpm until completely dissolved for 10 min to obtain solution a;

[0090] C. Mix polysorbate-20 with wild soybean extract and stir at 200 rpm until the emulsion mixture is clear and transparent. Stir for 10 minutes to obtain solution b.

[0091] D. Add rose essential oil dropwise to solution a at a rate of 0.7 mL per minute while stirring at a speed of 400 rpm for 20 minutes to obtain solution c.

[0092] E. Add solution b to solution c at a rate of 5.0 mL per minute while stirring at 500 rpm for 100 min to obtain solution d.

[0093] F. The solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 400W and the ultrasonic time was 5min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0094] Comparative Example 1: Without wild soybean extract

[0095] An essential oil nanocarrier, comprising, by weight percentage: 2.2% lavender essential oil, 7.7% hydroxypropyl-β-cyclodextrin, 10.0% polysorbate-60, 0.4785% methylpropanediol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0096] The preparation method of the above-mentioned essential oil nano-delivery carrier includes the following steps:

[0097] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-60, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0098] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 500 rpm until completely dissolved for 7 minutes to obtain solution a;

[0099] C. Add lavender essential oil dropwise to solution a at a rate of 0.7 mL per minute while stirring at 500 rpm for 25 minutes to obtain solution b.

[0100] D. Polysorbate-60 was added dropwise to solution b at a rate of 3.0 mL per minute, while stirring at 600 rpm for 80 minutes to obtain solution c.

[0101] E. Solution c was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 450W and the ultrasonic time was 10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0102] Comparative Example 2: Cells without ultrasonic cell disruptor treatment

[0103] An essential oil nanocarrier based on wild soybean extract comprises, by weight percentage: 1.6% lavender essential oil, 4.4% hydroxypropyl-β-cyclodextrin, 5.9% polysorbate-20, 0.3% wild soybean extract, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0104] The preparation method of the essential oil nanocarrier based on wild soybean extract includes the following steps:

[0105] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-20, wild soybean extract, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0106] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 600 rpm until completely dissolved for 10 min to obtain solution a;

[0107] C. Mix polysorbate-20 with wild soybean extract and stir at 200 rpm until the emulsion mixture is clear and transparent. Stir for 10 minutes to obtain solution b.

[0108] D. Add lavender essential oil dropwise to solution a at a rate of 0.8 mL per minute while stirring at a speed of 400 rpm for 20 minutes to obtain solution c.

[0109] E. Add solution b to solution c at a rate of 4.0 mL per minute while stirring at 500 rpm for 100 min to obtain solution d.

[0110] F. Preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, and 1,2-hexanediol were added to solution d to prepare an essential oil nano-delivery carrier. The obtained essential oil nano-delivery carrier was pale yellow and semi-transparent, and exhibited layering and oil exudation, indicating that it was extremely unstable.

[0111] Comparative Example 3: Direct mixing, without adding drops

[0112] An essential oil nanocarrier based on wild soybean extract comprises, by weight percentage: 1.3% lavender essential oil, 4.6% hydroxypropyl-β-cyclodextrin, 1.7% polysorbate-80, 1.2% wild soybean extract, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0113] The preparation method of the essential oil nanocarrier based on wild soybean extract includes the following steps:

[0114] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-80, wild soybean extract, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0115] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 400 rpm until completely dissolved for 5 minutes to obtain solution a;

[0116] C. Mix polysorbate-80 with wild soybean extract and stir at 100 rpm until the mixed emulsion is clear and transparent. The stirring time is 5 min to obtain solution b.

[0117] D. Add lavender essential oil directly to solution a and stir at a speed of 600 rpm for 30 minutes to obtain solution c;

[0118] E. Add solution b directly to solution c and stir at a speed of 400 rpm for 120 min to obtain solution d;

[0119] F. The solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 500W and the ultrasonic time was 10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0120] Comparative Example 4: Replacement of Wild Soybean Extract

[0121] An essential oil nanocarrier, comprising, by weight percentage: 1.3% lavender essential oil, 4.6% hydroxypropyl-β-cyclodextrin, 1.7% polysorbate-80, 1.2% inulin lauryl carbamate, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0122] The preparation method of the above-mentioned essential oil nano-delivery carrier includes the following steps:

[0123] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-80, inulin lauryl carbamate, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0124] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 400 rpm until completely dissolved for 5 minutes to obtain solution a;

[0125] C. Mix polysorbate-80 with inulin lauryl carbamate and stir at 100 rpm for 5 minutes to obtain solution b.

[0126] D. Add lavender essential oil dropwise to solution a at a rate of 0.6 mL per minute while stirring at a speed of 600 rpm for 30 minutes to obtain solution c.

[0127] E. Add solution b to solution c at a rate of 4.0 mL per minute while stirring at 400 rpm for 120 minutes to obtain solution d.

[0128] F. The solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 500W and the ultrasonic time was 10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier.

[0129] Comparative Example 5: Replacement of Wild Soybean Extract

[0130] An essential oil nanocarrier, comprising, by weight percentage: 1.3% lavender essential oil, 4.6% hydroxypropyl-β-cyclodextrin, 1.7% polysorbate-80, 1.2% cocamidopropyl hydroxysulfonate betaine, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0131] The preparation method of the above-mentioned essential oil nano-delivery carrier includes the following steps:

[0132] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-80, cocamidopropyl hydroxysulfonate betaine, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0133] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 400 rpm until completely dissolved for 5 minutes to obtain solution a;

[0134] C. Mix polysorbate-80 with cocamidopropyl hydroxysulfonate betaine and stir at 100 rpm for 5 min to obtain solution b.

[0135] D. Add lavender essential oil dropwise to solution a at a rate of 0.6 mL per minute while stirring at a speed of 600 rpm for 30 minutes to obtain solution c.

[0136] E. Add solution b to solution c at a rate of 4.0 mL per minute while stirring at 400 rpm for 120 minutes to obtain solution d.

[0137] F. Solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 500W, and the ultrasonic time was 10 min. Each ultrasonic on-time was 2.0-3.0 s, and the ultrasonic off-time was 2.0-3.0 s. After treatment, preservatives methylpropanediol, capryloyl hydroxamic acid, glyceryl caprylate, and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier. The obtained essential oil nano-delivery carrier was white and opaque, and showed stratification and oil exudation, indicating that it was extremely unstable.

[0138] Comparative Example 6: Replacement of Wild Soybean Extract

[0139] An essential oil nanocarrier, comprising, by weight percentage: 1.3% lavender essential oil, 4.6% hydroxypropyl-β-cyclodextrin, 1.7% polysorbate-80, 1.2% potassium cetyl phosphate, 0.4785% methyl propylene glycol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0140] The preparation method of the above-mentioned essential oil nano-delivery carrier includes the following steps:

[0141] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-80, potassium cetyl phosphate, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0142] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 400 rpm until completely dissolved for 5 minutes to obtain solution a;

[0143] C. Mix polysorbate-80 with potassium cetyl phosphate and stir at 100 rpm for 5 min to obtain solution b.

[0144] D. Add lavender essential oil dropwise to solution a at a rate of 0.6 mL per minute while stirring at a speed of 600 rpm for 30 minutes to obtain solution c.

[0145] E. Add solution b to solution c at a rate of 4.0 mL per minute while stirring at 400 rpm for 120 minutes to obtain solution d.

[0146] F. Solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 500W, and the ultrasonic time was 10 min. Each ultrasonic on-time was 2.0-3.0 s, and the ultrasonic off-time was 2.0-3.0 s. After treatment, preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier. The obtained essential oil nano-delivery carrier was white and opaque, and exhibited layering, oil exudation, and precipitation, indicating that it was extremely unstable.

[0147] Comparative Example 7: Replacement of Wild Soybean Extract

[0148] An essential oil nanocarrier, comprising, by weight percentage: 1.3% lavender essential oil, 4.6% hydroxypropyl-β-cyclodextrin, 1.7% polysorbate-80, 1.2% hexadecyltrimethylammonium chloride, 0.4785% methylpropanediol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0149] The preparation method of the above-mentioned essential oil nano-delivery carrier includes the following steps:

[0150] A. Weigh out the following ingredients according to the formula: lavender essential oil, hydroxypropyl-β-cyclodextrin, polysorbate-80, hexadecyltrimethylammonium chloride, methylpropanediol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0151] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 400 rpm until completely dissolved for 5 minutes to obtain solution a;

[0152] C. Mix polysorbate-80 with hexadecyltrimethylammonium chloride and stir at 100 rpm for 5 min to obtain solution b;

[0153] D. Add lavender essential oil dropwise to solution a at a rate of 0.6 mL per minute while stirring at a speed of 600 rpm for 30 minutes to obtain solution c.

[0154] E. Add solution b to solution c at a rate of 4.0 mL per minute while stirring at 400 rpm for 120 minutes to obtain solution d.

[0155] F. Solution d was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 500W, and the ultrasonic time was 10 min. Each ultrasonic on-time was 2.0-3.0 s, and the ultrasonic off-time was 2.0-3.0 s. After treatment, preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, and 1,2-hexanediol were added to prepare the essential oil nano-delivery carrier. The obtained essential oil nano-delivery carrier was white and opaque, and exhibited oil exudation, indicating that it was extremely unstable.

[0156] Comparative Example 8: Hollow Nanoparticle Delivery Carrier

[0157] A hollow nanodelivery carrier, by weight percentage, comprises the following components: 4.6% hydroxypropyl-β-cyclodextrin, 1.7% polysorbate-80, 1.2% wild soybean extract, 0.4785% methylpropanediol, 0.066% capryloyl hydroxamic acid, 0.0055% glyceryl caprylate, 0.55% 1,2-hexanediol, with the balance being deionized water.

[0158] The preparation method of the above-mentioned hollow nanodelivery carrier includes the following steps:

[0159] A. Weigh out the following ingredients according to the formula: hydroxypropyl-β-cyclodextrin, polysorbate-80, wild soybean extract, methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate, 1,2-hexanediol, and deionized water.

[0160] B. Mix hydroxypropyl-β-cyclodextrin with deionized water and stir with a stirrer at 400 rpm until completely dissolved for 5 minutes to obtain solution a;

[0161] C. Mix polysorbate-80 with wild soybean extract and stir at 100 rpm until the mixed emulsion is clear and transparent. The stirring time is 5 min to obtain solution b.

[0162] D. Add solution b to solution a at a rate of 4.0 mL per minute while stirring at 400 rpm for 120 minutes to obtain solution c.

[0163] E. Solution c was ultrasonically treated using an ultrasonic cell disruptor. The ultrasonic power was controlled at 500W and the ultrasonic time was 10min. The ultrasonic on time was 2.0-3.0s and the ultrasonic off time was 2.0-3.0s. After the treatment, the preservatives methyl propylene glycol, capryloyl hydroxamic acid, glyceryl caprylate and 1,2-hexanediol were added to prepare the hollow nanodelivery carrier.

[0164] Comparative Example 9: Lavender Essential Oil

[0165] Comparative Example 10:

[0166] To conduct efficacy comparison tests, Comparative Example 10 was set up. Comparative Example 10 was a mixed dilution of Comparative Example 8 and Comparative Example 9, with EpiGrowth culture medium containing 0.1% DMSO as the solvent. The final concentration of lavender essential oil / hollow nano-delivery carrier was consistent with that of the individual test solutions of Comparative Example 8 and Comparative Example 9 during the efficacy test.

[0167] Experimental example:

[0168] (I) Particle Size Testing: Particle size was tested and analyzed using a multi-angle particle size analyzer (Omni, Brookhaven, USA). The polydispersity index (PDI) is one of the important parameters characterizing the uniformity of particle distribution. The value is usually obtained by dynamic light scattering (DLS) measurement, reflecting the width and uniformity of particle size distribution. The following are descriptions of the particle size and appearance results of the nano-delivery carriers prepared in various embodiments and comparative examples of this invention. The test conditions for appearance stability are as follows: room temperature: 20-25℃, high temperature: 45℃, low temperature: -18℃ and 4℃, high and low temperature cycling: thermal cycling at -18℃, 4℃, and 45℃ for 24 hours at each temperature, and illumination: 4500±500 Lux.

[0169] Table 1. Appearance, stability, and particle size results of nanodelivery carriers

[0170]

[0171]

[0172] Table 1 (continued). Appearance, stability, and particle size results of nanodelivery carriers.

[0173]

[0174] As shown in Table 1, Examples 1-4 exhibit significant advantages over Comparative Examples 1-7 in terms of appearance, stability, and particle size. Specifically:

[0175] Comparing Example 2 and Comparative Example 1, it can be seen that without the addition of wild soybean extract, under the same preparation conditions and processes, the resulting nanodelivery carrier has a larger particle size and higher PDI (particulate density). Initially, it appears white and opaque. Stability tests also revealed layering and oil exudation. This is attributed to the fact that the high surface activity and spatial interaction of polysorbate emulsifiers at the O / W interface weaken over time, leading to accelerated aggregation of interfacial oil droplets and ultimately oil exudation. These results demonstrate that simply relying on the host-guest interaction between polysorbate emulsifiers and hydroxypropyl-β-cyclodextrin is insufficient to prepare stable and transparent nanodelivery carriers.

[0176] Comparing Example 3 and Comparative Example 2, it can be seen that when no ultrasonic treatment is performed during the preparation of the nanodelivery carrier, the resulting nanodelivery carrier exhibits a pale yellow, semi-transparent appearance, and shows layering and oil exudation. This is attributed to the fact that ultrasound can precisely control the intensity and frequency of liquid cavitation by controlling the frequency, thereby controlling the particle size and stability of the nanodelivery carrier. Ultrasonic treatment can also improve the solubility and thermal stability of the encapsulation formed by essential oil and hydroxypropyl-β-cyclodextrin by improving the complex structure and increasing molecular interactions (such as hydrogen bonds and hydrophobic interactions). Therefore, the preparation of the nanodelivery carrier of the present invention requires ultrasonic assistance with specific parameters.

[0177] Comparing Example 1 and Comparative Example 3, it can be seen that when the feed rate is not controlled during the preparation of the nanodelivery carrier, the final nanodelivery carrier has a larger particle size and an initial appearance of yellowish-white semi-transparent. This indicates that the fine emulsion and monodisperse emulsion formed by an appropriate feed rate can prevent oil droplets from agglomerating during the preparation process, ensuring that the oil phase entering the system is fully and uniformly dispersed, increasing the contact area between the two phases, increasing the emulsification rate, and forming a kinetically and thermodynamically stable nanodelivery carrier through high-energy homogenization and low-energy spontaneous emulsification. Therefore, a transparent and stable nanodelivery carrier requires strict control of the feed rate.

[0178] Comparing Examples 1 and 4-7, it is evident that, compared to mixed emulsifiers composed of other types of emulsifiers and polysorbate emulsifiers, the nanodelivery carrier prepared by the mixed emulsifier of wild soybean extract and polysorbate emulsifier exhibits better and more thorough emulsification. The resulting nanodelivery carrier has a smaller particle size, a lower PDI value, and is more stable and transparent. This may be because the soybean lecithin contained in wild soybean extract readily forms a buffer elastic layer with low surface tension at the O / W interface, promoting the establishment of a "channel" between the polysorbate emulsifier and the guest essential oil molecules. This self-assembles into a stable three-phase system of host, guest, and emulsifier, facilitating the rapid entry of the guest essential oil molecules into the hydrophobic cavity of the host. Ultimately, this results in an essential oil nanodelivery carrier with small particle size, high stability, high transparency, simple operation, high repeatability, and time and labor saving.

[0179] On the other hand, comparing Examples 3 and 4, both initially appeared transparent with particle sizes of 10-15 nm and PDI values ​​of 0.160 and 0.084, respectively. This indicates that the essential oil nanoparticle delivery carrier preparation method of this application is effective for one or more essential oils and has general applicability.

[0180] The above results demonstrate that the essential oil nano-delivery carrier of the present invention has a particle size of 10-30 nm, is transparent, and is stable.

[0181] (II) Morphological Characterization: The following is a description of the microstructure of the essential oil nanocarrier based on wild soybean extract prepared in Example 3 of this invention:

[0182] The microstructure of the essential oil nanocarrier was characterized by transmission electron microscopy (JEOL JEM-F200, Japan), such as... Figure 1 As shown, from Figure 1 It can be seen that the essential oil nano-delivery carrier prepared in Example 3 has a particle size of about 10-30 nm and a round or elliptical morphology, which confirms that the essential oil has been successfully encapsulated and further confirms the accuracy of the particle size test results.

[0183] (III) Surface Tension: The following is an explanation of the surface tension of the nano-delivery carriers prepared in Example 1 and Comparative Example 4 of this invention:

[0184] Surface tension refers to the force per unit length at the interface between a liquid and another phase (which can be a gas or another liquid) caused by the imbalance of molecular attraction at the surface of a liquid. It is mainly applicable to liquids. The lower the surface tension, the more conducive it is to the formation of essential oil nanoparticle delivery carriers, and the stronger the stability of the system. Surface tension is tested using the pendant drop method with a contact angle meter (Biolin Theta flex, Sweden). The basic principle of the pendant drop method for measuring surface tension is that when a droplet is suspended statically at the opening of a capillary tube, the shape of the droplet mainly depends on the balance between gravity and surface tension. Therefore, the surface tension of the liquid can be calculated by measuring the shape of the droplet. In the experiment, the sample volume was set to 8 μL, the droplet was suspended in the air, and the test was conducted for 1 minute. Under the control of software, a pendant droplet of appropriate volume was automatically formed, and after waiting for 60 seconds, the surface tension value was obtained by image analysis and calculation of the formed droplet.

[0185] Depend on Figure 2 It can be seen that the emulsifiers in Examples 1 and 4 migrated rapidly on the droplet surface, quickly reaching equilibrium before the droplets were fully formed. This allowed for sufficient distribution of emulsifier molecules on the surface. This is mainly due to the relatively low proportion of emulsifier in both examples, with deionized water being the dominant solvent, resulting in a near-monolithic structure without a significant content difference. Therefore, the process of emulsifier molecules migrating and adsorbing from the solvent to the surface did not occur, leading to a stable surface tension curve. Within the first 60 seconds, the surface tension scatter plot of Example 1 showed better overall stability than that of Comparative Example 4, and the surface tension values ​​of Example 1 were generally lower than those of Comparative Example 4.

[0186] The above results confirm that the soybean lecithin contained in wild soybean extract can easily form a buffer elastic layer with low surface tension at the O / W interface, which further reduces the surface tension of the entire essential oil nano-delivery carrier system and enhances its stability.

[0187] (iv) Encapsulation efficiency: The following describes the thermal stability and sustained-release performance of the essential oil nanocarriers based on wild soybean extract prepared in various embodiments of the present invention:

[0188] The thermal stability and sustained-release properties of the essential oil nanocarriers were analyzed using a thermogravimetric analyzer (Netzsch STA449F3, Germany). Approximately 3–5 mg of samples were heated at a rate of 10 °C / min within the range of 30–800 °C under constant nitrogen flow to investigate the thermal stability of Examples 1 / 2 / 3, Comparative Example 1, and lavender essential oil, as well as the sustained-release properties of Examples 1 / 2 / 3.

[0189] Thermogravimetric analysis (TG) curves represent the weight change of a sample with temperature during a programmed temperature process, while derivative thermogravimetric analysis (DTG) curves are the differential equations of the TG curves, representing the rate of weight change with temperature. The peaks of the DTG curve correspond to the inflection points of the TG curves, representing the points where the rate of weight loss is at its maximum. The number of peaks in the DTG curve is equal to the number of steps in the TG curve. Figure 3 It can be seen that the thermal decomposition process of the essential oil nanocarrier prepared in Example 2 is mainly divided into four stages: the 30-100℃ stage is mainly due to the volatilization of water and a small amount of impurities; the weight loss peak that appears at 180-250℃ is mainly due to the gradual carbonization and decomposition of polysorbate emulsifiers, and the essential oil encapsulated in the nanocarrier also begins to be gradually released at this stage; the small amount of weight loss that appears at 300-350℃ is mainly attributed to the decomposition of wild soybean extract; at a temperature of about 380℃, the wall material hydroxypropyl-β-cyclodextrin is finally carbonized and decomposed. In contrast, the thermogravimetric analysis results of Comparative Example 1 showed only two main weight loss peaks, at approximately 30–100℃ and 350–400℃, which may be attributed to the decomposition of moisture and a small amount of impurities, and the carbonization and decomposition of hydroxypropyl-β-cyclodextrin, respectively. This also confirms the instability of the encapsulation system in Comparative Example 1. The sample had already released oil during the thermogravimetric analysis test, and the tested sample mainly contained water and hydroxypropyl-β-cyclodextrin, consistent with its stability appearance results. This further indicates that the nano-delivery carrier containing wild soybean extract has good thermal stability.

[0190] Depend on Figure 4 It can be seen that the trend of the thermogravimetric analysis results in Examples 1 / 2 / 3 is basically consistent with that of the other examples. Figure 3The thermogravimetric analysis results of Example 2 are consistent with those of Examples 1, 2, and 3. The final weight loss rates (wt.%) of Examples 1, 2, and 3 were 86.90%, 71.65%, and 80.35%, respectively. The difference in weight loss rates among the three is mainly attributed to the volatilization of moisture and a small amount of impurities in the first 100°C, which is also consistent with the order of solid content in the preparation conditions of Examples 1, 2, and 3. The thermogravimetric analysis results of lavender essential oil show that the essential oil volatilizes rapidly and continuously within the range of 30–200°C until it is almost completely decomposed. In contrast, the essential oil encapsulated in Examples 1, 2, and 3 is gradually released mainly in the range of 180–400°C, further indicating that the nano-delivery carrier delays the release of the essential oil and has a sustained-release effect.

[0191] The above results demonstrate that the essential oil nano-delivery carrier has excellent thermal stability and a long-lasting sustained-release effect.

[0192] (V) Efficacy Testing: The following are descriptions of the efficacy testing of the nanodelivery carriers prepared in the various embodiments and comparative examples of this invention:

[0193] Efficacy testing was conducted using the following experimental method: a skin photoaging model was established by irradiating isolated skin tissue with a combination of UVA and UVB rays. A blank control group and a negative control group (30 J / cm²) were included in the experiment. 2 UVA +50mJ / cm 2 UVB) and sample group (30J / cm) 2 UVA +50mJ / cm 2 UVB+ Examples 1 / Comparative Examples 3 / 4 / 8 / 9 / 10), with 3 replicates per group. After culturing ex vivo skin tissue for 2 days, except for the blank control group, the other groups began irradiation and drug administration, with a daily irradiation dose of UVA 30 J / cm². 2 and UVB 50mJ / cm 2 During irradiation, the culture medium was discarded and replaced with PBS buffer. UVA irradiation was performed first, followed by UVB irradiation, for four consecutive days. After each irradiation, the culture medium was replaced with fresh medium, and surface drug administration was performed. Different groups of test solutions were added to the surface of the ex vivo skin tissue, with a volume of 10 μL. After four days of continuous irradiation, the ex vivo skin tissue was cultured for another three days, receiving only drug administration without irradiation. After culture, the surface of the ex vivo skin tissue was washed to remove any remaining test solution and residual liquid. The tissue was fixed with 4% paraformaldehyde, then embedded and sectioned. After dewaxing, loricrin (LOR) was immunofluorescently stained, and photographs were taken under a microscope within 24 hours. Three images from different fields of view were acquired. The relative IOD of the target signal in the images was analyzed using Ipwin32 image analysis software, and the average value was calculated. Using the blank control group as a baseline, the relative IOD / area average was calculated to characterize the relative protein expression level.

[0194] The test solution was a dilution of the samples from Example 1 and Comparative Examples 3 / 4 / 8, diluted 10 times, and the dilution solvent was EpiGrowth culture medium; the test solution for Comparative Example 9 was 0.13% lavender essential oil, and the solvent was EpiGrowth culture medium containing 0.1% DMSO; Comparative Example 10 was the stock solution test; the test solutions for the blank control group and the negative control group were blank EpiGrowth culture medium.

[0195] Lobelin (LOR) is a major component of the keratin capsule in final differentiated keratinocytes. In the stratum corneum, LOR is cross-linked to the keratin capsule by transglutaminase, playing a crucial role in the barrier repair function of the epidermis. (See Table 2 and...) Figure 5 It was found that, compared with the blank control group, the LOR content in the negative control group was significantly reduced under ultraviolet irradiation (P<0.01), indicating that ultraviolet irradiation damages proteins related to skin barrier structure, causing skin damage. Compared with the negative control group, the use of Examples 1 / Comparative Examples 3 / 4 / 8 / 9 / 10 after ultraviolet irradiation significantly increased the LOR content (P<0.05), playing a certain repair role in the skin barrier, but the improvement ability varied. The improvement rates of LOR for Examples 1 / Comparative Examples 3 / 4 / 8 / 9 / 10 were 267.30%, 159.39%, 98.81%, 53.03%, 74.83%, and 138.52%, respectively. Comparative Examples 8 and 9 were hollow nano-delivery carrier and lavender essential oil, respectively, both of which had a certain LOR improvement effect, indicating that the use of wild soybean extract and lavender essential oil alone can improve LOR to a certain extent. Example 1 showed the highest improvement in LOR (Leakage Rate). Comparative Example 3 showed a lower LOR improvement than Example 1, mainly because Example 1 had a suitable dripping rate, resulting in a stable and intact nano-delivery carrier system with more significant repair performance. Comparative Example 4 showed a lower LOR improvement than Example 1, attributed to the presence of wild soybean extract in Example 1, indicating that the wild soybean extract in the nano-delivery carrier has a good barrier repair effect. Comparative Example 10 showed a lower LOR improvement than Example 1, possibly due to the volatile nature of essential oils; unencapsulated essential oils easily dissipate, resulting in a short duration of action on the skin, directly affecting the barrier repair effect. The LOR improvement rates of Examples 1 and Comparative Examples 3 / 10 were higher than those of Comparative Examples 8 / 9, indicating a synergistic effect between wild soybean extract and lavender essential oil in barrier repair.

[0196] Table 2. Effect of the test solutions of Example 1 / Comparative Examples 3 / 4 / 8 / 9 / 10 on the relative content of phlotoxin

[0197]

[0198] The above results further verify that the essential oil nanodelivery carrier based on wild soybean extract has good barrier repair effects, and that the essential oil and wild soybean extract in the essential oil nanodelivery carrier have a synergistic effect in repair.

[0199] (vi) Formulation Application: The following is a description of the transparent aqueous formulation of the essential oil nano-delivery carrier based on wild soybean extract prepared using Example 3 of the present invention:

[0200] Prepare aqueous solutions according to the aqueous formulations in Table 3, and test the stability of the aqueous solutions.

[0201] Table 3. Formulation and stability test results of aqueous products

[0202]

[0203] As shown in Table 3, the aqueous products prepared by the essential oil nano-delivery carrier provided in this application have the characteristics of good stability and high transparency.

[0204] The above demonstrates that it is feasible to apply the essential oil nano-delivery carrier based on wild soybean extract provided in this application to the formulation of transparent aqueous cosmetics.

Claims

1. A nanodelivery carrier of essential oils based on Glycine max extract, characterized in that, The essential oil nano delivery carrier based on wild soybean extract comprises the following components: essential oil, hydroxypropyl-β-cyclodextrin, polysorbate emulsifier, wild soybean extract, and water; the polysorbate emulsifier is selected from one or more of polysorbate-20, polysorbate-60, and polysorbate-80; and the effective component of the wild soybean extract is mainly soybean lysophosphatidylcholine. The mass percentage of the hydroxypropyl-β-cyclodextrin is 4.0-9.0%; the mass percentage of the essential oil is 0.001-2.5%; the mass percentage of the polysorbate emulsifier is 1.5-7.0%; the mass percentage of the wild soybean extract is 0.2-2.0%; and the balance is deionized water; and the essential oil nano delivery carrier further comprises a preservative, and the mass percentage of the preservative is 0.005-1.2%. The preparation method of the essential oil nano delivery carrier based on wild soybean extract comprises the following steps: (a) mixing hydroxypropyl-β-cyclodextrin with water, stirring until completely dissolved to obtain solution a; (b) mixing polysorbate emulsifier with wild soybean extract, stirring until the mixed emulsifier is in a clear and transparent state to obtain solution b; (c) dropping essential oil into solution a at a dropping speed of 0.6-0.8 mL per minute, and stirring while dropping to obtain solution c; (d) dropping solution b into solution c at a dropping speed of 3.0-5.0 mL per minute, and stirring while dropping to obtain solution d; (e) performing ultrasonic treatment on solution d, controlling the ultrasonic power to be 400-500 W, the ultrasonic time to be 5-10 min, the ultrasonic opening time to be 2.0-3.0 s, and the ultrasonic closing time to be 2.0-3.0 s, and then adding a preservative to prepare the essential oil nano delivery carrier.

2. The nano-delivery carrier of essential oils as claimed in claim 1, wherein, The mass percentage of the essential oil is 1.0-2.5%.

3. The nano-delivery vehicle of essential oils as claimed in claim 1, wherein, The essential oil comprises one or more of essential oils of lavender, rose, rose geranium, sandalwood, bergamot, patchouli, clary sage, complete ylang-ylang, sweet orange, pink grapefruit, peppermint, organic cranberry berry, atlantic cedar, orange flower, lemon grass, lemon, tea tree, jasmine, rosemary, frankincense, myrrh, thyme, heather, storax, scots pine, silk pine, wintergreen, eucalyptus, oregano, ginger, cinnamon, laurel, nutmeg, anise, clove, and roman chamomile.

4. The nano-delivery carrier of essential oils as claimed in claim 1, wherein, The preservative comprises one or more of chlorphenesin, methylpropanediol, caprylyl oxyhydroxamic acid, glyceryl caprylate, phenoxyethanol, p-hydroxyacetophenone, 1,2-hexanediol, propylene glycol, pentylene glycol, caprylyl glycol, ethylhexylglycerin, methylisothiazolinone, methylchloroisothiazolinone, magnesium nitrate, magnesium chloride, benzalkonium bromide, benzalkonium chloride, glutaraldehyde, isopentyldiol, o-cymen-5-ol, diazolidinyl urea, iodopropynyl butylcarbamate, sodium hydroxymethylglycinate, DMDM hydantoin, sorbic acid and its salts, benzoic acid and its salts and esters, and benzyl alcohol.

5. The nano-delivery vehicle for essential oils of claim 1, wherein, The preservative comprises methylpropanediol, caprylyl oxyhydroxamic acid, glyceryl caprylate, and 1,2-hexanediol.

6. The nano-delivery vehicle for essential oils of claim 1, wherein, The essential oil nano-delivery carrier is a transparent liquid with light yellow to dark yellow color, and the microstructure is round or oval with a particle size of 10-30 nm.

7. The nano-delivery vehicle for essential oils of claim 1, wherein, The preparation method of the essential oil nano-delivery carrier based on wild soybean extract meets one or more of the following conditions: i. In step (a), the stirring speed is 400-600 rpm, and the stirring time is 5-10 min; ii. In step (b), the stirring speed is 100-200 rpm, and the stirring time is 5-10 min; iii. In step (c), the stirring speed is 400-600 rpm, and the stirring time is 20-30 min; iv. In step (d), the stirring speed is 400-600 rpm, and the stirring time is 60-120 min.

8. Use of the essential oil nano-delivery carrier based on wild soybean extract of claim 1 as a fragrance or moisturizing and repairing active substance in the preparation of skin care products, wherein the essential oil nano-delivery carrier has the functions of moisturizing, barrier repairing, skin-friendly penetration promoting, and aroma slow release, and the wild soybean extract and the essential oil have a synergistic effect in repairing.

9. Use of the essential oil nano-delivery carrier based on wild soybean extract of claim 1 in the preparation of transparent aqueous cosmetic products.

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