Plant essential oil soothing repair emulsion and preparation method thereof

Abstract

This invention belongs to the field of cosmetic technology, specifically relating to a plant essential oil soothing and repairing emulsion and its preparation method. Rose essential oil, squalane, vitamin E, and rosehip oil are mixed to obtain an oil phase. This oil phase is then added to an aqueous phase and homogenized to obtain the plant essential oil soothing and repairing emulsion. In this invention, cyclodextrin succinate is used to modify zein, and the resulting composite particles serve as the first emulsion solid particles. Silk fibroin is used as the second emulsion particle. During emulsion preparation, the two particles bind at the oil-water interface through hydrogen bonds and electrostatic adsorption, improving the emulsion's stability. Furthermore, both are natural materials, reducing the risk of skin irritation and sensitization.

Description

Technical Field

[0001] This invention belongs to the field of cosmetic technology, specifically relating to a plant essential oil soothing and repairing lotion and its preparation method. Background Technology

[0002] Skin lotions typically require surfactants or traditional small-molecule emulsifiers to reduce the interfacial tension between oil and water in order to obtain a stable emulsion system. However, commonly used emulsifiers in existing technologies (such as polyoxyethylene ethers, polyglycerol esters, and ionic surfactants) have significant application drawbacks.

[0003] On the one hand, these emulsifiers have strong interfacial adsorption and permeability, which can easily disrupt the orderly lipid structure of the stratum corneum, leading to impaired skin barrier function, increased transepidermal water loss, and consequently, discomfort such as dryness, tightness, and stinging. On the other hand, some emulsifiers themselves or their impurities (such as byproducts like 1,4-dioxane and unreacted ethylene oxide) are sensitizing, activating skin immune cells and causing the release of inflammatory factors, manifesting as erythema, itching, or even allergic contact dermatitis.

[0004] Especially for people with sensitive skin, whose skin barrier function is already weak and whose nerve perception threshold is lowered, their tolerance to traditional emulsifiers is even worse, and the risk of allergic reactions after using regular skin care lotions is significantly increased.

[0005] To alleviate this problem, existing technologies have attempted to reduce the amount of emulsifier used, or to use alternatives such as high molecular weight polymers or solid particles (such as Pickering emulsifiers). However, these methods often suffer from problems such as insufficient emulsion stability, poor skin feel, complex processes, or unsatisfactory biocompatibility of raw materials.

[0006] Therefore, developing a skin lotion that not only has good emulsification stability but also significantly reduces the risk of skin irritation and sensitization (especially sensitive skin) and soothes and repairs sensitive skin remains a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to provide a plant essential oil soothing and repairing emulsion and its preparation method to solve the above-mentioned technical problems.

[0008] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows:

[0009] A method for preparing a plant essential oil soothing and repairing lotion includes the following steps:

[0010] S1. Dissolve zein in an aqueous ethanol solution and stir at room temperature until dissolved. Then add resveratrol and stir for 3-3.5 hours to obtain a resveratrol-loaded solution.

[0011] Add succinic acid cyclodextrin ester to deionized water, stir to dissolve, and adjust the pH to 4.5-5.0 to obtain succinic acid cyclodextrin ester solution;

[0012] The resveratrol-loaded solution was slowly added to the succinic acid cyclodextrin ester solution. After removing the ethanol by rotary evaporation, a composite particle dispersion was obtained. After dialyzing with deionized water, the dispersion was freeze-dried to obtain zein-succinic acid cyclodextrin ester composite particles loaded with resveratrol.

[0013] S2. Add the zein-succinate cyclodextrin ester composite particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A.

[0014] Silk fibroin was dissolved in deionized water to prepare a 2% (w / w) silk fibroin aqueous solution. Then, the silk fibroin aqueous solution was diluted with 1 mmol / L sodium chloride solution to a silk fibroin protein mass fraction of 1% to obtain solution B.

[0015] Adjust the pH of solution A to 5.6-6.0 and the pH of solution B to 4-4.2. Then mix solutions A and B and stir at room temperature to obtain the aqueous phase.

[0016] S3. Mix rose essential oil, squalane, vitamin E and rosehip oil to obtain the oil phase. Under stirring conditions, slowly add the oil phase to the aqueous phase and homogenize to obtain a plant essential oil soothing and repairing emulsion.

[0017] As a further improvement, in step S1, the preparation method of the succinic acid cyclodextrin ester is as follows: β-cyclodextrin, succinic acid, and sodium hypophosphite are fully dissolved in deionized water to prepare a mixed solution. The mixed solution is poured into a glass petri dish, dried, and then transferred to an oven at 140~145℃ for dry-heat esterification reaction. After the reaction is completed, the mixture is cooled to room temperature, the product is dissolved in deionized water, and then the precipitate is separated with anhydrous ethanol. After washing, the product is dried to obtain the succinic acid cyclodextrin ester.

[0018] As a further improvement, the molar ratio of β-cyclodextrin to succinic acid is 1:6.5~7.5, and the mass ratio of sodium hypophosphite to β-cyclodextrin is 1:1~1.1.

[0019] As a further improvement, the reaction time of the dry heat esterification reaction is 12-16 min.

[0020] As a further improvement, in step S1, the mass ratio of zein, resveratrol, and cyclodextrin succinate is 1:0.1:0.4~0.6, the volume fraction of the ethanol aqueous solution is 85%, and the molecular weight cutoff for dialysis is 15 kDa.

[0021] As a further improvement, in step S2, the mass ratio of solution A to solution B is 2~3:1.

[0022] As a further improvement, in step S3, the volume ratio of rose essential oil, squalane, vitamin E and rosehip oil is 0.05~0.1:2:0.05~0.1:1.

[0023] As a further improvement, in step S3, the volume ratio of the oil phase to the water phase is 4:6.

[0024] As a further improvement, in step S3, the stirring conditions are specifically 1500~2000 rpm, and the homogenization is specifically 17000 rpm for 2~5 minutes.

[0025] This invention also provides a plant essential oil soothing and repairing lotion.

[0026] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0027] This invention provides a plant essential oil soothing and repairing emulsion and its preparation method. The method involves using succinic acid cyclodextrin ester to modify zein protein, and the resulting composite particles are used as the first emulsion solid particles. Silk fibroin is used as the second emulsion particle. During the emulsion preparation process, the two particles are combined at the oil-water interface through hydrogen bonds and electrostatic adsorption, which improves the stability of the emulsion. Both particles are natural materials, which can reduce the risk of skin irritation and sensitization.

[0028] In this invention, succinic acid cyclodextrin ester is used to modify zein. Through non-covalent interactions such as hydrophobic interaction, hydrogen bonding and electrostatics, it binds to the zein molecular chain, induces secondary structure rearrangement, weakens the hydrophobic association between zein molecules, inhibits the molecular aggregation of zein, and makes the composite particles more stable at the oil-water interface, thus improving the stability of the emulsion.

[0029] In this invention, succinic acid cyclodextrin ester is used to introduce a carboxyl group into the β-cyclodextrin molecule. During the adsorption and binding of silk fibroin at the oil-water interface, the hydrogen bonding force between the ester and silk fibroin is stronger, which improves the interaction force between the first emulsified solid particles and the second emulsified solid particles, and further enhances the stability of the emulsion.

[0030] In this invention, during the preparation of succinic acid cyclodextrin ester, different reaction times affect the esterification reaction, which in turn affects the content of carboxyl groups in the succinic acid cyclodextrin ester. Grafting of succinic acid affects the hydrophilicity and hydrophobicity of the succinic acid cyclodextrin ester, which in turn affects the stability of the composite particles at the oil-water interface. At the same time, the content of carboxyl groups in the succinic acid cyclodextrin ester also affects the interaction force between the composite particles and silk fibroin.

[0031] Therefore, by setting a specific dry-heat esterification reaction time and setting a specific ratio of zein and cyclodextrin succinate during the preparation of composite particles, the present invention ensures the stability of the composite particles at the oil-water interface while maintaining the interaction force between the composite particles and silk fibroin, thereby achieving high stability of the emulsion.

[0032] In this invention, sodium chloride solution is added during the preparation of solution B. The addition of sodium ions can improve the stability of silk fibroin at the oil-water interface, thereby improving the overall stability of the emulsion. Attached Figure Description

[0033] Figure 1 This is the infrared spectrum of succinic acid cyclodextrin ester in Example 1;

[0034] Figure 2 The infrared spectra of zein (Z) and zein-succinate cyclodextrin ester composite particles (ZC) loaded with resveratrol in Example 1 are shown.

[0035] Figure 3 This is a graph showing the irritation results of the experimental group, negative control group, and positive control group in a cosmetic eye irritation test. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0037] In this invention, the method for adjusting pH can use substances permitted in cosmetic preparation, and the specific method can be selected as needed. It does not affect the stability of the plant essential oil soothing and repairing emulsion in this invention.

[0038] Example 1: A method for preparing a plant essential oil soothing and repairing lotion, comprising the following steps:

[0039] S1. Dissolve 5.68 g (5 mmol) β-cyclodextrin, 4.19 g (35.5 mmol) succinic acid and 5.68 g sodium hypophosphite in 60 mL of deionized water to prepare a mixed solution;

[0040] The mixed solution was poured into a glass petri dish and dried in an oven at 100°C for 3 hours. The dried material was then transferred to an oven at 140°C for a dry-heat esterification reaction. After 12 minutes, the reaction was completed and cooled to room temperature. The product was then dissolved in 20 mL of deionized water. The succinic acid cyclodextrin ester in the product was separated and precipitated with anhydrous ethanol. The product was washed three times with anhydrous ethanol and dried thoroughly at 50°C for 6 hours to obtain succinic acid cyclodextrin ester.

[0041] like Figure 1 The image shown is the infrared spectrum of succinic acid cyclodextrin ester. Figure 1 It can be seen that at 1730cm -1 A stretching vibration peak of the ester group appears at 3423 cm⁻¹. -1 and 1160cm -1 The peaks at these locations represent the stretching vibrations of -OH and COC, respectively.

[0042] S2. Dissolve 2.5g of zein (Z) in 250mL of 85% ethanol aqueous solution, stir at room temperature and 400rpm for 2h to dissolve, then add 0.25g of resveratrol and stir for 3h to obtain resveratrol loaded solution.

[0043] Add 1.0 g of cyclodextrin succinate to 50 mL of deionized water, stir to dissolve, and adjust the pH to 4.5 to obtain a cyclodextrin succinate solution.

[0044] The resveratrol loading solution was slowly added to the succinic acid cyclodextrin ester solution, the ethanol was removed by rotary evaporation at 50°C, the solution was dialyzed with deionized water (molecular weight cutoff of 15 kDa) for 48 h and then freeze-dried to obtain zein-succinic acid cyclodextrin ester composite particles loaded with resveratrol (ZC).

[0045] S3. Add the zein-succinate cyclodextrin ester composite particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A.

[0046] Silk fibroin was dissolved in deionized water to prepare a 2% (w / w) silk fibroin aqueous solution. The silk fibroin aqueous solution was then diluted with 1 mmol / L sodium chloride solution to a 1% (w / w) solution, which is solution B.

[0047] Adjust the pH of solution A to 5.6 and the pH of solution B to 4.0. Then mix solution A and solution B at a mass ratio of 3:1 and stir magnetically for 5 minutes at room temperature to obtain the aqueous phase.

[0048] S4. Rose essential oil, squalane, vitamin E and rosehip oil are mixed in a volume ratio of 0.05:2:0.05:1 to obtain an oil phase. The oil phase is then slowly added to the aqueous phase in a volume ratio of 4:6 under stirring at 1500 rpm. The mixture is then homogenized at 17000 rpm for 2 minutes to obtain a plant essential oil soothing and repairing emulsion.

[0049] In this embodiment, other moisturizing substances, such as glycerin and butylene glycol, may be added to the aqueous phase, all of which are existing technologies.

[0050] In this embodiment, the carboxyl group content of the prepared succinic acid cyclodextrin ester was 1.68 mmol / g, and the specific test method was as follows:

[0051] First, prepare a 0.1 mol / L NaOH solution and a 0.1 mol / L HCl solution. Dissolve 100 mg of cyclodextrin succinate in 40 mL of NaOH solution, and then titrate with HCl until the solution pH = 7.0.

[0052] The carboxyl content is calculated using the formula: Carboxyl content = (c1×v1-c2×v2) / w;

[0053] Where c1 and v1 are the concentration (mol / L) and volume (mL) of the NaOH solution, respectively; c2 and v2 are the concentration (mol / L) and volume (mL) of the HCl solution, respectively; and w is the mass (g) of succinic acid cyclodextrin ester.

[0054] like Figure 2 The image shows the infrared spectra of zein (Z) and zein-succinate cyclodextrin ester complex particles loaded with resveratrol (ZC). Figure 2 It can be seen that amide I of zein (approximately 1650 cm⁻¹) -1 ) and amide II band (approximately 1540cm) -1 The slight displacement and weakening of intensity in the composite particles indicate that some C=O and NH may interact with the hydroxyl groups of succinic acid cyclodextrin ester through hydrogen bonds.

[0055] In addition, composite particles are located at 3300~3400 cm⁻¹ -1 The OH / NH stretching vibration peak is wider than that of zein within the range, which also indicates that the hydroxyl groups of succinic acid cyclodextrin ester molecules have hydrogen bonding with the zein molecular chain.

[0056] Example 2: A method for preparing a plant essential oil soothing and repairing lotion, comprising the following steps:

[0057] S1. Dissolve 5.68 g (5 mmol) β-cyclodextrin, 3.84 g (32.5 mmol) succinic acid and 5.68 g sodium hypophosphite in 60 mL of deionized water to prepare a mixed solution;

[0058] The mixed solution was poured into a glass petri dish and dried in an oven at 100°C for 3 hours. The dried material was then transferred to an oven at 145°C for dry-heat esterification. After 16 minutes, the reaction was completed and cooled to room temperature. The product was then dissolved in 20 mL of deionized water. The succinic acid cyclodextrin ester in the product was separated and precipitated with anhydrous ethanol. The product was washed three times with anhydrous ethanol and dried thoroughly at 50°C for 6 hours to obtain succinic acid cyclodextrin ester.

[0059] S2. Dissolve 2.5g of zein in 250mL of 85% ethanol aqueous solution, stir at room temperature and 400rpm for 2h to dissolve, then add 0.25g of resveratrol and stir for 3.5h to obtain resveratrol loaded solution.

[0060] Add 1.5g of succinic acid cyclodextrin ester to 50mL of deionized water, stir to dissolve, and adjust the pH to 5.0 to obtain a succinic acid cyclodextrin ester solution.

[0061] The resveratrol loading solution was slowly added to the succinic acid cyclodextrin ester solution, the ethanol was removed by rotary evaporation at 50℃, the solution was dialyzed with deionized water (molecular weight cutoff of 15 kDa) for 48 h and then freeze-dried to obtain zein-succinic acid cyclodextrin ester composite particles loaded with resveratrol.

[0062] S3. Add the zein-succinate cyclodextrin ester composite particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A.

[0063] Silk fibroin was dissolved in deionized water to prepare a 2% (w / w) silk fibroin aqueous solution. The silk fibroin aqueous solution was then diluted with 1 mmol / L sodium chloride solution to a 1% (w / w) solution, which is solution B.

[0064] Adjust the pH of solution A to 6.0 and the pH of solution B to 4.2. Then mix solution A and solution B at a mass ratio of 2:1 and stir magnetically at room temperature for 10 minutes to obtain the aqueous phase.

[0065] S4. Rose essential oil, squalane, vitamin E and rosehip oil are mixed in a volume ratio of 0.1:2:0.1:1 to obtain an oil phase. The oil phase is then slowly added to the aqueous phase in a volume ratio of 4:6 under stirring at 2000 rpm. The mixture is then homogenized at 17000 rpm for 5 minutes to obtain a plant essential oil soothing and repairing emulsion.

[0066] In this embodiment, the carboxyl content in succinic acid cyclodextrin ester is 2.05 mmol / L, and the specific test method is the same as in Example 1.

[0067] Example 3: A method for preparing a plant essential oil soothing and repairing lotion, comprising the following steps:

[0068] S1. Dissolve 5.68 g (5 mmol) β-cyclodextrin, 4.43 g (37.5 mmol) succinic acid and 6.25 g sodium hypophosphite in 60 mL of deionized water to prepare a mixed solution;

[0069] The mixed solution was poured into a glass petri dish and dried in an oven at 100°C for 3 hours. The dried material was then transferred to an oven at 143°C for a dry-heat esterification reaction. After 14 minutes, the reaction was completed and cooled to room temperature. The product was then dissolved in 20 mL of deionized water. The succinic acid cyclodextrin ester in the product was separated and precipitated with anhydrous ethanol. The product was washed three times with anhydrous ethanol and dried thoroughly at 50°C for 6 hours to obtain succinic acid cyclodextrin ester.

[0070] S2. Dissolve 2.5g of zein in 250mL of 85% ethanol aqueous solution, stir at room temperature and 400rpm for 2h to dissolve, then add 0.25g of resveratrol and stir for 3.3h to obtain resveratrol loaded solution.

[0071] Add 1.25g of succinic acid cyclodextrin ester to 50mL of deionized water, stir to dissolve, and adjust the pH to 4.8 to obtain a succinic acid cyclodextrin ester solution.

[0072] The resveratrol loading solution was slowly added to the succinic acid cyclodextrin ester solution, the ethanol was removed by rotary evaporation at 50℃, the solution was dialyzed with deionized water (molecular weight cutoff of 15 kDa) for 48 h and then freeze-dried to obtain zein-succinic acid cyclodextrin ester composite particles loaded with resveratrol.

[0073] S3. Add the zein-succinate cyclodextrin ester composite particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A.

[0074] Silk fibroin was dissolved in deionized water to prepare a 2% (w / w) silk fibroin aqueous solution. The silk fibroin aqueous solution was then diluted with 1 mmol / L sodium chloride solution to a 1% (w / w) solution, which is solution B.

[0075] The pH of solution A was adjusted to 5.8, and the pH of solution B was adjusted to 4.1. Then, solutions A and B were mixed at a mass ratio of 2.5:1 and magnetically stirred at room temperature for 8 minutes to obtain the aqueous phase.

[0076] S4. Rose essential oil, squalane, vitamin E and rosehip oil are mixed in a volume ratio of 0.08:2:0.08:1 to obtain an oil phase. The oil phase is then slowly added to the aqueous phase in a volume ratio of 4:6 under stirring at 1800 rpm. The mixture is then homogenized at 17000 rpm for 3 minutes to obtain a plant essential oil soothing and repairing emulsion.

[0077] Comparative Example 1: A method for preparing a plant essential oil soothing and repairing lotion, differing from Example 1 in that silk fibroin is not added in step S3. The specific steps are as follows:

[0078] S1. Dissolve 5.68 g (5 mmol) β-cyclodextrin, 4.19 g (35.5 mmol) succinic acid and 5.68 g sodium hypophosphite in 60 mL of deionized water to prepare a mixed solution;

[0079] The mixed solution was poured into a glass petri dish and dried in an oven at 100°C for 3 hours. The dried material was then transferred to an oven at 140°C for a dry-heat esterification reaction. After 12 minutes, the reaction was completed and cooled to room temperature. The product was then dissolved in 20 mL of deionized water. The succinic acid cyclodextrin ester in the product was separated and precipitated with anhydrous ethanol. The product was washed three times with anhydrous ethanol and dried thoroughly at 50°C for 6 hours to obtain succinic acid cyclodextrin ester.

[0080] S2. Dissolve 2.5g of zein (Z) in 250mL of 85% ethanol aqueous solution, stir at room temperature and 400rpm for 2h to dissolve, then add 0.25g of resveratrol and stir for 3h to obtain resveratrol loaded solution.

[0081] Add 1.0 g of cyclodextrin succinate to 50 mL of deionized water, stir to dissolve, and adjust the pH to 4.5 to obtain a cyclodextrin succinate solution.

[0082] The resveratrol loading solution was slowly added to the succinic acid cyclodextrin ester solution, the ethanol was removed by rotary evaporation at 50°C, the solution was dialyzed with deionized water (molecular weight cutoff of 15 kDa) for 48 h and then freeze-dried to obtain zein-succinic acid cyclodextrin ester composite particles loaded with resveratrol (ZC).

[0083] S3. Add the zein-succinate cyclodextrin ester composite particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A.

[0084] A 0.5 mol / L sodium chloride solution was used as solution B;

[0085] Adjust the pH of solution A to 5.6 and the pH of solution B to 4.0. Then mix solution A and solution B at a mass ratio of 3:1 and stir magnetically for 5 minutes at room temperature to obtain the aqueous phase.

[0086] S4. Rose essential oil, squalane, vitamin E and rosehip oil are mixed in a volume ratio of 0.05:2:0.05:1 to obtain an oil phase. The oil phase is then slowly added to the aqueous phase in a volume ratio of 4:6 under stirring at 1500 rpm. The mixture is then homogenized at 17000 rpm for 2 minutes to obtain a plant essential oil soothing and repairing emulsion.

[0087] Comparative Example 2: A method for preparing a plant essential oil soothing and repairing lotion, differing from Example 1 in that it does not use succinic acid cyclodextrin ester to modify zein. The specific steps are as follows:

[0088] S1. Dissolve 2.5g of zein (Z) in 250mL of 85% ethanol aqueous solution, stir at room temperature and 400rpm for 2h to dissolve, then add 0.25g of resveratrol and stir for 3h to obtain resveratrol loaded solution.

[0089] S2. Resveratrol loading solution is used as solution A;

[0090] Silk fibroin was dissolved in deionized water to prepare a 2% (w / w) silk fibroin aqueous solution. The silk fibroin aqueous solution was then diluted with 1 mmol / L sodium chloride solution to a 1% (w / w) solution, which is solution B.

[0091] Adjust the pH of solution A to 5.6 and the pH of solution B to 4.0. Then mix solution A and solution B at a mass ratio of 3:1 and stir magnetically for 5 minutes at room temperature to obtain the aqueous phase.

[0092] S3. Rose essential oil, squalane, vitamin E and rosehip oil are mixed in a volume ratio of 0.05:2:0.05:1 to obtain an oil phase. The oil phase is then slowly added to the aqueous phase in a volume ratio of 4:6 under stirring at 1500 rpm. The mixture is then homogenized at 17000 rpm for 2 minutes to obtain a plant essential oil soothing and repairing emulsion.

[0093] Comparative Example 3: A method for preparing a plant essential oil soothing and repairing lotion, differing from Example 1 in that β-cyclodextrin is used instead of succinic acid cyclodextrin ester. The specific steps are as follows:

[0094] S1. Dissolve 2.5g of zein (Z) in 250mL of 85% ethanol aqueous solution, stir at room temperature and 400rpm for 2h to dissolve, then add 0.25g of resveratrol and stir for 3h to obtain resveratrol loaded solution.

[0095] Add 1.0 g of β-cyclodextrin to 50 mL of deionized water, stir to dissolve, and adjust the pH to 4.5 to obtain a β-cyclodextrin solution.

[0096] The resveratrol-loaded solution was slowly added to the β-cyclodextrin solution, the ethanol was removed by rotary evaporation at 50°C, the solution was dialyzed with deionized water (molecular weight cutoff of 15 kDa) for 48 h and then freeze-dried to obtain zein-cyclodextrin composite particles loaded with resveratrol.

[0097] S2. Add the zein-cyclodextrin complex particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A.

[0098] Silk fibroin was dissolved in deionized water to prepare a 2% (w / w) silk fibroin aqueous solution. The silk fibroin aqueous solution was then diluted with 1 mmol / L sodium chloride solution to a 1% (w / w) solution, which is solution B.

[0099] Adjust the pH of solution A to 5.6 and the pH of solution B to 4.0. Then mix solution A and solution B at a mass ratio of 3:1 and stir magnetically for 5 minutes at room temperature to obtain the aqueous phase.

[0100] S3. Rose essential oil, squalane, vitamin E and rosehip oil are mixed in a volume ratio of 0.05:2:0.05:1 to obtain an oil phase. The oil phase is then slowly added to the aqueous phase in a volume ratio of 4:6 under stirring at 1500 rpm. The mixture is then homogenized at 17000 rpm for 2 minutes to obtain a plant essential oil soothing and repairing emulsion.

[0101] Comparative Example 4: A method for preparing a plant essential oil soothing and repairing lotion, differing from Example 1 in that sodium chloride solution is not added during the preparation of solution B. The specific steps are as follows:

[0102] S1. Dissolve 5.68 g (5 mmol) β-cyclodextrin, 4.19 g (35.5 mmol) succinic acid and 5.68 g sodium hypophosphite in 60 mL of deionized water to prepare a mixed solution;

[0103] The mixed solution was poured into a glass petri dish and dried in an oven at 100°C for 3 hours. The dried material was then transferred to an oven at 140°C for a dry-heat esterification reaction. After 12 minutes, the reaction was completed and cooled to room temperature. The product was then dissolved in 20 mL of deionized water. The succinic acid cyclodextrin ester in the product was separated and precipitated with anhydrous ethanol. The product was washed three times with anhydrous ethanol and dried thoroughly at 50°C for 6 hours to obtain succinic acid cyclodextrin ester.

[0104] S2. Dissolve 2.5g of zein (Z) in 250mL of 85% ethanol aqueous solution, stir at room temperature and 400rpm for 2h to dissolve, then add 0.25g of resveratrol and stir for 3h to obtain resveratrol loaded solution.

[0105] Add 1.0 g of cyclodextrin succinate to 50 mL of deionized water, stir to dissolve, and adjust the pH to 4.5 to obtain a cyclodextrin succinate solution.

[0106] The resveratrol loading solution was slowly added to the succinic acid cyclodextrin ester solution, the ethanol was removed by rotary evaporation at 50℃, the solution was dialyzed with deionized water (molecular weight cutoff of 15 kDa) for 48 h and then freeze-dried to obtain zein-succinic acid cyclodextrin ester composite particles loaded with resveratrol.

[0107] S3. Add the zein-succinate cyclodextrin ester composite particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A.

[0108] Dissolve silk fibroin in deionized water to prepare a 1% (w / w) silk fibroin aqueous solution, which is solution B.

[0109] Adjust the pH of solution A to 5.6 and the pH of solution B to 4.0. Then mix solution A and solution B at a mass ratio of 3:1 and stir magnetically for 5 minutes at room temperature to obtain the aqueous phase.

[0110] S4. Rose essential oil, squalane, vitamin E and rosehip oil are mixed in a volume ratio of 0.05:2:0.05:1 to obtain an oil phase. The oil phase is then slowly added to the aqueous phase in a volume ratio of 4:6 under stirring at 1500 rpm. The mixture is then homogenized at 17000 rpm for 2 minutes to obtain a plant essential oil soothing and repairing emulsion.

[0111] Comparative Example 5: A method for preparing a plant essential oil soothing and repairing emulsion, which differs from Example 1 in that the dry heat esterification reaction time in the preparation process of succinic acid cyclodextrin ester is 20 min.

[0112] Comparative Example 6: A method for preparing a plant essential oil soothing and repairing emulsion, which differs from Example 1 in that the dry heat esterification reaction time is 6 minutes during the preparation of succinic acid cyclodextrin ester.

[0113] Stability tests were conducted on the plant essential oil soothing and repairing lotions of Example 1 and Comparative Examples 1-6.

[0114] Heat resistance test: Take three samples, place one at 60℃, one at 40℃, and one at room temperature, and store for 2 weeks, 4 weeks, and 6 weeks. After the storage period, take them out and allow them to return to room temperature. Compare the three samples and observe whether discoloration occurs. Centrifuge at 10000r / min for 30min and observe whether stratification occurs to evaluate the heat resistance performance of the product.

[0115] Cold resistance test: Take two samples, one placed at room temperature and the other stored at -20℃ in a refrigerator for 2 weeks, 4 weeks and 6 weeks. After the storage period, take them out and wait for them to return to room temperature. Compare the samples and observe whether discoloration occurs. Centrifuge at 10000r / min for 30min and observe whether stratification occurs.

[0116] Cold and heat cycling test: Take two samples, place one at room temperature and the other at -20°C in a refrigerator. After 24 hours, transfer the sample to 40°C and place it for another 24 hours. Repeat this process 3 times. After the sample returns to room temperature, compare the two samples and observe whether color change occurs. Centrifuge at 10000 r / min for 30 minutes and observe whether stratification occurs.

[0117] The results of the stability test are shown in Tables 1-3.

[0118] Table 1. Heat resistance test results of emulsions from Example 1 and Comparative Examples 1-6

[0119]

[0120] Table 2. Cold resistance test results of emulsions from Example 1 and Comparative Examples 1-6

[0121]

[0122] Table 3. Results of thermal cycling tests on emulsions from Example 1 and Comparative Examples 1-6

[0123]

[0124] As can be seen from Tables 1-3, the emulsion prepared by the present invention has the best stability. The stability of the emulsions prepared by Comparative Examples 1-6 all decreased to varying degrees, resulting in different degrees of stratification in the heat resistance test, cold resistance test and thermal cycling test.

[0125] The irritant properties of the emulsion prepared in Example 1 were tested according to the "Cosmetic Eye Irritation Test - Chicken Embryo Viral Allantoic Membrane Test" (T / SHRH011-2018). The test method was as follows:

[0126] Place the eggs in a fully automatic incubator, maintain humidity above 70%, turn the eggs every 2 hours, remove unfertilized eggs on the 7th day, and continue incubating fertilized eggs;

[0127] Test groups: 6 animals per group, divided into experimental group, negative control (0.9% NaCl) and positive control (0.1mol / L NaOH);

[0128] On day 9 of incubation, the experiment began. The air cell shell was carefully peeled off with dental tweezers. A few drops of physiological saline were dripped onto the surface of the shell membrane to moisten it. After pouring it out, the shell membrane was removed with tweezers, ensuring that the exposed allantoic membrane remained intact and undamaged. 0.3g of the emulsion prepared in Example 1 was applied to the sealing film in the experimental group, spreading it as widely as possible to ensure a coverage area of ​​at least 50%. After 3 minutes, it was gently rinsed with pure water, completing the rinsing within 30 seconds. The liquid was poured out, and the degree of change in each toxic effect was immediately observed under a stereomicroscope and scored (ES). The endpoint method was used to evaluate the effect of the test sample on the vascularity of the chicken embryo chorioallantoic membrane.

[0129] like Figure 3 The figure shown represents the irritation results for the experimental group, negative control group, and positive control group.

[0130] As shown in Tables 4 and 5, these are the scoring table and the result evaluation criteria, respectively. Based on the criteria in Tables 4 and 5, the emulsion prepared in Example 1 was evaluated and scored 3.14, which is considered "non-irritating / mildly irritating".

[0131] Table 4 Endpoint Method Scoring Table

[0132]

[0133] Table 5 Evaluation Criteria for Endpoint Method Results

[0134]

[0135] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a plant essential oil soothing repair emulsion, characterized in that, Includes the following steps: S1. Dissolve zein in an aqueous ethanol solution and stir at room temperature until dissolved. Then add resveratrol and stir for 3-3.5 hours to obtain a resveratrol-loaded solution. Add succinic acid cyclodextrin ester to deionized water, stir to dissolve, and adjust the pH to 4.5-5.0 to obtain succinic acid cyclodextrin ester solution; The resveratrol-loaded solution was slowly added to the succinic acid cyclodextrin ester solution. After removing the ethanol by rotary evaporation, a composite particle dispersion was obtained. After dialyzing with deionized water, the dispersion was freeze-dried to obtain zein-succinic acid cyclodextrin ester composite particles loaded with resveratrol. S2. Add the zein-succinate cyclodextrin ester composite particles loaded with resveratrol to deionized water to prepare a 1% (w / w) solution A. Silk fibroin was dissolved in deionized water to prepare a 2% (w / w) silk fibroin aqueous solution. Then, the silk fibroin aqueous solution was diluted with 1 mmol / L sodium chloride solution to a silk fibroin protein mass fraction of 1% to obtain solution B. Adjust the pH of solution A to 5.6-6.0 and the pH of solution B to 4-4.

2. Then mix solutions A and B and stir at room temperature to obtain the aqueous phase. S3. Mix rose essential oil, squalane, vitamin E and rosehip oil to obtain the oil phase. Under stirring conditions, slowly add the oil phase to the aqueous phase and homogenize to obtain a plant essential oil soothing and repairing emulsion.

2. The method of preparing a plant essential oil soothing repair emulsion according to claim 1, characterized in that, In step S1, the preparation method of the succinic acid cyclodextrin ester is as follows: β-cyclodextrin, succinic acid, and sodium hypophosphite are fully dissolved in deionized water to prepare a mixed solution. The mixed solution is poured into a glass petri dish, dried, and then transferred to an oven at 140~145℃ for dry-heat esterification reaction. After the reaction is completed, the mixture is cooled to room temperature, the product is dissolved in deionized water, and then the precipitate is separated with anhydrous ethanol. After washing and drying, succinic acid cyclodextrin ester is obtained.

3. The method of preparing a plant essential oil soothing repair emulsion according to claim 2, characterized in that, The molar ratio of β-cyclodextrin to succinic acid is 1:6.5~7.5, and the mass ratio of sodium hypophosphite to β-cyclodextrin is 1:1~1.

1.

4. The method of preparing a plant essential oil soothing repair emulsion according to claim 3, characterized in that, The reaction time for the dry heat esterification reaction is 12-16 min.

5. The method for preparing the plant essential oil soothing and repairing emulsion according to claim 1, characterized in that, In step S1, the mass ratio of zein, resveratrol, and cyclodextrin succinate is 1:0.1:0.4~0.6, the volume fraction of the ethanol aqueous solution is 85%, and the molecular weight cutoff for dialysis is 15 kDa.

6. The method for preparing the plant essential oil soothing and repairing emulsion according to claim 1, characterized in that, In step S2, the mass ratio of solution A to solution B is 2~3:

1.

7. The method for preparing the plant essential oil soothing and repairing emulsion according to claim 1, characterized in that, In step S3, the volume ratio of rose essential oil, squalane, vitamin E and rosehip oil is 0.05~0.1:2:0.05~0.1:

1.

8. The method for preparing the plant essential oil soothing and repairing emulsion according to claim 7, characterized in that, In step S3, the volume ratio of the oil phase to the water phase is 4:

6.

9. The method for preparing the plant essential oil soothing and repairing emulsion according to claim 8, characterized in that, In step S3, the stirring conditions are specifically 1500~2000 rpm, and the homogenization is specifically homogenization at 17000 rpm for 2~5 min.

10. A plant essential oil soothing and repairing lotion, characterized in that, The plant essential oil soothing and repairing lotion is prepared by the method described in claim 1.

Images