Liposome hydrogel patch based on African plant essential oil and eutectic solvent

Abstract

The invention provides a formula and a preparation method of a multifunctional composite component skin hydrogel patch. The patch is fused with the Argan nut essential oil, the South African passion flower essential oil and the eutectic solvent in the optimal proportion, the Argan nut essential oil-South African passion flower essential oil-eutectic solvent nano-liposome is prepared by adopting an injection method firstly, then the hydrogel patch is prepared through crosslinking and gelation, and finally a homogeneous film which is smooth in surface and transparent in appearance is formed. The related preparation process is simple, mild in condition, free of special equipment and easy for large-scale production. When the film is used as a body surface patch, good elasticity and adhesiveness are shown, meanwhile, obvious swelling property and moisturizing capacity are shown, the potential of serving as a plant essential oil release carrier is shown, and the film can nourish and improve the skin. The whole system makes full use of the special nursing effect of the African plant essential oil, cooperates with multiple effects of the eutectic solvent, and ensures the stability of the nano-liposome under different environmental conditions at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of health care, and in particular relates to a composite component nanoliposome hydrogel patch containing plant essential oil with skin-improving function and a preparation method thereof. Background Art

[0002] The skin is not only the body's largest organ, but also performs multiple functions, including protection, perception, and regulation. Despite the continuous improvement of modern living standards, skin health faces increasing challenges. Environmental pollution, dietary habits, electromagnetic radiation, and mental stress can all negatively impact the skin, making it increasingly important to maintain healthy skin. In today's lifestyle and living environment, skin problems are increasing, such as dryness, pigmentation, aging, darkening, keratinization, sensitivity, and more complex skin diseases, all of which require effective maintenance, care, and treatment options. While there are already some daily chemical products, health supplements, pharmaceuticals, and medical devices targeting skin problems on the market, there is still room for improvement in terms of functional diversity, basic formulas, stability, ease of use, duration of use, absorption and utilization, and preparation methods.

[0003] Many natural plant essential oils have been found to possess excellent skin care properties, particularly in terms of antioxidant, anti-inflammatory, antibacterial, and neoplastic properties. These essential oils positively impact wound healing through a variety of mechanisms, including improving local blood circulation, inhibiting the growth of pathogenic microorganisms, and modulating immune responses. Africa is a vast continent, with significant geographical and climatic differences between the north and south. The continent boasts a rich variety of plant species, found across diverse geographical regions. Many of these are rare or unique natural resources, but due to limited resources, they have not been efficiently developed and utilized. Argan oil (also known as argan oil) is a precious oil found in the kernels of the Argania spinosa tree, a species endemic to Morocco in North Africa. It is rich in vitamin E, essential fatty acids (such as linoleic and oleic acid), and antioxidants. Argan oil has been used for centuries and is considered a beauty secret for Moroccan women. It has the effects of moisturizing the skin, reducing wrinkles, treating acne, and eliminating scars (D. Guillaume, Z. Charrouf, Argan oil and other argan products: Use in dermocosmetology, European Journal of Lipid Science and Technology, 2011, 113(4), 403-408). South African passionflower essential oil is a light oil extracted from the seeds of South African passionflower (Passiflora caerulea L.). It is rich in polyphenols, vitamins A and C, minerals, and essential fatty acids, especially linoleic acid. Existing research shows that it has strong anti-aging properties, especially the proanthocyanidins and flavonoids it contains, which exhibit significant antioxidant capacity and collagenase inhibitory activity (K. Bravo, L. Duque, F. Ferreres, et al., Passiflora tarminiana fruits reduce UVB-induced photoaging in human skin fibroblasts, Journal of Photochemistry and Photobiology B, 2017, 168, 78-88). These African plant essential oils are highly favored in skin health products due to their rich active ingredients and significant skin care effects. On the other hand, although these essential oils have shown great potential in improving skin, they are currently mainly applied directly to the body surface. How to scientifically compound them and effectively deliver them to deep tissues to exert their effects remains a major challenge. The volatility, stability, and compatibility of the components contained in natural essential oils with the body are all issues that need to be addressed.

[0004] As an emerging green solvent, deep eutectic solvent (DES) is a new multi-purpose green solvent composed of a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) in a specific molar ratio. It exists in liquid form at room temperature and is currently in its infancy in the field of comprehensive health. Compared with traditional media, DES has demonstrated significant advantages in structural designability, versatility, broad solubility, ideal stability, and biocompatibility (many HBDs and HBAs are derived from natural sources). The latest generation of DES, due to the use of natural compounds with various bioactive properties as HBDs and HBAs, also has certain care or therapeutic effects, some of which have the effect of improving skin (such as phytic acid-betaine DES, C. Chen, Y. Wang, W. Jiang, et al., Transdermal release behaviors of bioactive deep eutectic solvents as natural skin care and mechanism, Journal of Molecular Liquids, 2022, 367, 120412). Thanks to its aforementioned properties, DES has been used to prepare functional materials with potential clinical applications (e.g., T. Huang, YB Zhang, L. Zhao, et al., Sodium hyaluronate hydrogel for wound healing and human health monitoring based on deep eutectic solvent, International Journal of Biological Macromolecules, 2024, 257, 128801). Combined with its advantages as a green solvent and its ability to promote the delivery and penetration of active ingredients, DES shows great potential in enhancing topical transdermal absorption and the activity of functional substances, indicating its broad application prospects in the current field of skin care and nursing. Its multifunctionality, i.e., multi-purpose use of a single substance, can simplify the system composition and play multiple roles.

[0005] Nanostructured lipid carriers are the second generation of lipid nanoparticles, which can effectively overcome the shortcomings of solid lipid nanoparticles. Liposomes have inherent characteristics such as biocompatibility and degradability, and their nanoscale size has attracted much attention in many fields such as life sciences, biomedicine, cosmetics and food (Y. Panahi, M. Farshbaf, M. Mohammadhosseini, et al., Recent advances on liposomal nanoparticles: synthesis, characterization and biomedical applications, Artificial Cells, Nanomedicine, and Biotechnology, 2017, 45, 788-799). Nanoliposomes are spherical vesicles with a lipid bilayer membrane. They can encapsulate lipophilic functional components in the lipid bilayer and hydrophilic functional components in the aqueous compartment. This feature makes them compatible with different types of active substances. In particular, it has also attracted attention in the field of cosmeceuticals and has been used in many aspects such as acne treatment, improvement of pigmentation and chloasma treatment, and promotion of scar healing. It can effectively increase the retention of various active substances in the skin (S. Rohilla, A. Rohilla, S. Narwal, et al., Global trends of cosmeceutical in nanotechnology: A review, 2023, 11(5), 410-424).

[0006] Hydrophilic gels, also known as hydrogels, are networks composed of polymer chains, sometimes also appearing in the form of colloidal gels, with water as the dispersion medium. Hydrogels can lock a large amount of water in their structure and can respond to the actual application environment. These hydrogels can be prepared by cross-linking water-soluble polymers or converting hydrophobic polymers into hydrophilic polymers, and then forming a network by cross-linking. Hydrogels have a range of different application forms, including microneedles, microparticles, nanoparticles, coatings, sponges, and membranes. With their unique moisturizing and responsive properties, hydrogels have shown ideal application effects in many fields such as beauty, medicine, and health (TCHo, CCChang. HPChan, et al., Hydrogels: Properties and applications in biomedicine, Molecules, 2022, 27(9): 2902). Among them, acrylamide-based hydrogels are a network structure formed by the polymerization of acrylamide monomers (or their derivatives), usually prepared by free radical polymerization reactions. They are a type of hydrophilic gel that can absorb and retain a large amount of water in their network structure and have shown excellent and stable performance in applications in this field.

[0007] In the current health care and beauty field, although transdermal permeation systems are often used for skin treatment and daily maintenance, they are often faced with problems such as unstable effect, inconvenient use, limited effect, low absorption and utilization efficiency, or irritation to sensitive skin. These limitations hinder the relevant products from achieving optimal efficacy, safety, and user experience, affect their potential in promoting skin health and nursing effects, and the development and utilization of characteristic natural products with a long history of use in different parts of the world is also urgently needed to be expanded. The present invention is a scientific combination of argan oil, passionflower essential oil, and a deep eutectic solvent, and is simultaneously prepared into a nanoliposome hydrogel patch in a convenient and effective manner, providing a useful reference for the design and creation of existing health care products. The entire system combines the natural antioxidant and skin regeneration properties of argan oil and the anti-inflammatory and whitening effects of passionflower essential oil, collaborates with the various advantages of deep eutectic solvents in enhancing dissolution, dispersion, molding, penetration, and ingredient efficacy, and realizes the stabilization and effective release of functional substances using nanoliposome hydrogel as a carrier, so that it can better play the role of responding to multiple daily care needs such as skin tissue regeneration, pigmentation repair, anti-aging, and moisturizing. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for preparing a multifunctional composite component skin hydrogel patch, wherein the core components involved include argan essential oil, South African passion fruit essential oil, low eutectic solvent, etc.; the preparation process involved is simple, the conditions are mild, and no special equipment is required. When used as a surface patch, the film exhibits good elasticity and adhesion, while showing obvious swelling and moisturizing ability, which can provide nourishment and improvement for the skin. The entire system fully exerts the unique care effects of African plant essential oils, while ensuring the stability of nanoliposomes under different environmental conditions. The good physical and chemical properties of each component in the preparation process reflect obvious combination advantages. The overall properties, functional integration and mechanical strength of the nanoliposome composite film prepared from two plant essential oils and low eutectic solvents are good. The composite film has a smooth appearance and good uniformity; it is easy to cut and easy to achieve large-scale preparation. It has good basic performance during use and also reflects the characteristics of being a release carrier for plant essential oils.

[0009] Technical solution: In order to achieve the above objectives, a liposome hydrogel patch based on African plant essential oils and a low eutectic solvent and a preparation method thereof are proposed.

[0010] The liposome hydrogel patch based on African plant essential oil and deep eutectic solvent described in the present invention is characterized in that the liposome hydrogel patch first uses African plant essential oil and deep eutectic solvent as key components to prepare nanoliposomes, and then obtains the final product hydrogel patch through crosslinking and gelation.

[0011] The above-mentioned liposome hydrogel patch based on African plant essential oils and deep eutectic solvents is characterized in that argan essential oil and South African passionflower essential oil are mixed and compounded in a volume ratio of 2:1 to 1:2 as the functional material of the liposome hydrogel patch.

[0012] The above-mentioned liposome hydrogel patch based on African plant essential oil and deep eutectic solvent is characterized in that the deep eutectic solvent used is composed of phytic acid and betaine, and the molar ratio of the two components is 3:1 to 1:3, and it plays multiple roles as an essential oil solvent, film-forming aid, penetration enhancer and auxiliary functional substance at the same time.

[0013] The above-mentioned liposome hydrogel patch based on African plant essential oils and deep eutectic solvents is characterized in that a compound of argan essential oil and South African passionflower essential oil is mixed with a phytic acid-betaine deep eutectic solvent in a volume ratio of 1:1 to 1:2.

[0014] The above-mentioned liposome hydrogel patch based on African plant essential oils and deep eutectic solvents is characterized in that the nanoliposomes are prepared by an injection method, and the specific steps are:

[0015] (1) dissolving soybean lecithin and cholesterol in a mixed solvent of ethanol and methanol to prepare a saturated solution as a lipid solution, wherein the mass ratio of the soybean lecithin to the cholesterol is 1:1 to 1:2, and the volume ratio of the ethanol to the methanol is 2:1 to 3:1;

[0016] (2) a mixture of the above two African plant essential oils and a deep eutectic solvent was prepared into a saturated solution in phosphate PBS buffer as an aqueous medium, and heated to 60° C. in a water bath;

[0017] (3) adding the aqueous medium obtained in step (2) dropwise to the lipid solution obtained in step (1), and then subjecting the entire system to ultrasonic dispersion, wherein the ultrasonic power is 300 to 500 W and the ultrasonic time is 10 to 20 min; removing the volatile solvent under reduced pressure, and standing at 4° C. to obtain a nanoliposome product.

[0018] The above-mentioned liposome hydrogel patch based on African plant essential oil and deep eutectic solvent is characterized in that the obtained nanoliposomes are mixed with sodium alginate and bentonite aqueous solution, and then acrylamide, ammonium peroxide dicarboxylate and N,N,N',N'-tetramethylethylenediamine solution are added in sequence, and a transparent film patch is prepared by crosslinking and gelation. The specific steps are:

[0019] (1) Sodium alginate and ultrapure water were mixed at a mass ratio of 1:50 and stirred to obtain a clear sodium alginate solution. Bentonite and ultrapure water were then mixed at a mass ratio of 1:100, added to the sodium alginate aqueous solution, and stirred thoroughly in a 40°C water bath until the mixture was uniformly mixed.

[0020] (2) adding the prepared nanoliposomes to the mixed solution in step (1) at a volume ratio of 1:100, and then adding acrylamide at a volume mass ratio of 1:7.5 (mL / g) to the nanoliposomes to the mixed solution and mixing thoroughly;

[0021] (3) adding a 1 mg / mL N,N-methylenebisacrylamide aqueous solution at a volume mass ratio of 1:0.005 (mL / g) to the nanoliposomes to the mixed solution obtained in step (2), stirring thoroughly, adding a 10 mg / mL ammonium peroxide dicarboxylate aqueous solution at a volume mass ratio of 1:0.05 (mL / g) to the nanoliposomes and a 0.76 mg / mL N,N,N',N'-tetramethylethylenediamine aqueous solution at a volume mass ratio of 1:0.05-0.10 (mL / g), and crosslinking and gelation were carried out in a 60°C water bath for 0.5-1h;

[0022] (4) Pour the reaction product obtained in step (3) into a mold while it is hot, cool and let it stand until it is completely formed, then open the film, dry it under reduced pressure at 50°C for 3 hours, sterilize it with ultraviolet light for 60 minutes, slice it, package it, and store it in a vacuum. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more completely illustrate the technical solutions of the specific embodiments of the present invention, the following briefly describes the drawings required in the embodiments. The drawings described are only part of the embodiments of the present invention. Those skilled in the art should be able to derive other drawings of the embodiments based on these drawings. Among them:

[0024] Figure 1 This is the antioxidant activity (AA%) test result of the Argan essential oil-Passiflora edulis essential oil compound of the present invention.

[0025] Figure 2 This is the encapsulation efficiency measurement result of the Argan Oil-Passiflora Essential Oil-deep eutectic solvent nanoliposome in the present invention.

[0026] Figure 3 This is a scanning electron micrograph (×15000) of the argan essential oil-South African passionflower essential oil-deep eutectic solvent nanoliposomes of the present invention.

[0027] Figure 4 The figure shows the appearance of the nanoliposome hydrogel patch of the present invention and its adhesion state on the skin.

[0028] Figure 5 This is a cross-sectional photograph (×1200) of the nanoliposome hydrogel patch of the present invention observed under a scanning electron microscope.

[0029] Figure 6This is the infrared spectrum (FT-IR) of the nanoliposome hydrogel patch of the present invention.

[0030] Figure 7 The swelling results of the nanoliposome hydrogel patch of the present invention are shown in the figure (37° C., standard PBS solution; 1 to 7 h).

[0031] Figure 8 The results are the moisturizing ability test results of the nanoliposome hydrogel patch of the present invention (37° C.; 1 to 7 h). DETAILED DESCRIPTION

[0032] The following is a detailed description of the present invention. Although specific embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0033] This specification and claims do not distinguish components based on differences in terminology, but rather on differences in their functions. The terms "including" and "comprising" used in this application are open-ended and should be interpreted as meaning "including but not limited to." The examples described later in this specification are preferred embodiments of the present invention and are intended to serve as general guidelines for the purposes of this specification and are not intended to limit the scope of the invention.

[0034] Example 1

[0035] Argan oil and passionflower oil were mixed at a volume ratio of 2:1 and stirred at 500 rpm at room temperature until fully mixed to obtain an essential oil compound.

[0036] Example 2

[0037] Argan oil and passionflower oil were mixed at a volume ratio of 1:1 and stirred at 500 rpm at room temperature until fully mixed to obtain an essential oil compound.

[0038] Example 3

[0039] Argan oil and passionflower oil were mixed at a volume ratio of 1:2 and stirred at 500 rpm at room temperature until fully mixed to obtain an essential oil compound.

[0040] Example 4

[0041] Betaine and phytic acid were heated and stirred in a water bath at a molar ratio of 3:1 at 60°C. After a transparent liquid was formed, the mixture was dried under reduced pressure to obtain a deep eutectic solvent, which was then stored in a vacuum for later use.

[0042] Example 5

[0043] Betaine and phytic acid were heated and stirred in a water bath at 60° C. in a molar ratio of 1:1. After a transparent liquid was formed, the mixture was dried under reduced pressure to obtain a deep eutectic solvent, which was then stored in a vacuum for later use.

[0044] Example 6

[0045] Betaine and phytic acid were heated and stirred in a water bath at a molar ratio of 1:3 at 60° C., and after a transparent liquid was formed, the mixture was dried under reduced pressure to obtain a deep eutectic solvent, which was then stored in a vacuum for later use.

[0046] Example 7

[0047] (1) Soybean lecithin and cholesterol in a mass ratio of 1:1 were dissolved in a mixed solvent of ethanol and methanol in a volume ratio of 7:3 to prepare a saturated lipid solution;

[0048] (2) 1 g of the essential oil compound obtained in Example 2 and 1 g of the DES obtained in Example 4 were added to 50 mL of PBS buffer and mixed uniformly to prepare an aqueous medium, which was then heated to 60° C. in a water bath;

[0049] (3) The aqueous medium was added dropwise to the lipid solution, and the solution was ultrasonically treated at 500 W for 15 min. The volatile solvent was removed under reduced pressure, and the solution was allowed to stand at 4°C to obtain the nanoliposome product.

[0050] Example 8

[0051] (1) Soybean lecithin and cholesterol in a mass ratio of 1:2 were dissolved in a mixed solvent of ethanol and methanol in a volume ratio of 7:3 to prepare a saturated lipid solution;

[0052] (2) 1 g of the essential oil compound obtained in Example 2 and 1 g of the DES obtained in Example 4 were added to 50 mL of PBS buffer and mixed uniformly to prepare an aqueous medium, which was then heated to 60° C. in a water bath;

[0053] (3) The aqueous medium was added dropwise to the lipid solution, and the solution was ultrasonically treated at 500 W for 15 min. The volatile solvent was removed under reduced pressure, and the solution was allowed to stand at 4°C to obtain the nanoliposome product.

[0054] Example 9

[0055] (1) Weigh 2 g of sodium alginate and mix it with 100 mL of ultrapure water for 30 min. Then, mix 0.1 g of bentonite with 10 mL of ultrapure water and add it to the sodium alginate solution. Stir thoroughly in a 40°C water bath until the mixture is uniform.

[0056] (2) Add 2 mL of the nanoliposomes prepared in Example 7, and then add 15 g of acrylamide and stir to mix;

[0057] (3) adding 0.01 g of 1 mg / mL N,N-methylenebisacrylamide aqueous solution to the system in step (2), and finally adding 0.10 g of 10 mg / mL ammonium peroxide dicarboxylate aqueous solution and 0.16 g of 0.76 mg / mL N,N,N',N'-tetramethylethylenediamine aqueous solution, and performing crosslinking and gelation at 60°C for 0.5 h;

[0058] (4) Pour the reaction product obtained in step (3) into the mold while it is hot, cool and let it stand until it is completely formed, then open the film, dry it under reduced pressure at 50°C for 3 hours, and sterilize it under ultraviolet light for 60 minutes. Cut the finished product into 1 mm thin slices, package them, and store them in a vacuum.

[0059] Example 10

[0060] (1) Weigh 2 g of sodium alginate and mix it with 100 mL of ultrapure water for 30 min. Then, mix 0.1 g of bentonite with 10 mL of ultrapure water and add it to the sodium alginate solution. Stir thoroughly in a 40°C water bath until the mixture is uniform.

[0061] (2) Add 2 mL of the nanoliposomes prepared in Example 8, and then add 15 g of acrylamide and stir to mix;

[0062] (3) adding 0.01 g of 1 mg / mL N,N-methylenebisacrylamide aqueous solution to the system in step (2), and finally adding 0.10 g of 10 mg / mL ammonium peroxide dicarboxylate aqueous solution and 0.20 g of 0.76 mg / mL N,N,N',N'-tetramethylethylenediamine aqueous solution, and performing crosslinking and gelation at 60°C for 1 hour;

[0063] (4) Pour the reaction product obtained in step (3) into the mold while it is hot, cool and let it stand until it is completely formed, then open the film, dry it under reduced pressure at 50°C for 3 hours, and sterilize it under ultraviolet light for 60 minutes. Cut the finished product into 1 mm thin slices, package them, and store them in a vacuum.

[0064] Based on the recognized T / SHRH006-2018 Cosmetics - Free Radical (DPPH) Scavenging Test Method, 2,2′-diphenyl-1-picrylhydrazyl (DPPH) reagent was used to evaluate and compare the antioxidant activities (AA%) of the essential oil compounds prepared in Examples 1, 2, and 3, pure argan essential oil, and South African passionflower essential oil. The specific procedures are as follows:

[0065] Mix 200 μL of sample with 2.8 mL of ethanol, then add 2 mL of 0.004% DPPH ethanol solution. Shake thoroughly and store at room temperature in the dark for 30 minutes. Measure the absorbance of the sample at a wavelength of 517 nm using UV-visible spectrophotometry, using pure ethanol as a negative control. Calculate the free radical scavenging activity (DPPH, %) using the following formula: DPPH%=(A c -A s ) / A c ×100 Where Ac is the absorbance of the control group and As is the absorbance of the sample.

[0066] The results of the free radical scavenging activity (DPPH,%) of the above samples are shown in the attached Figure 1 As shown in the results, the antioxidant activity of Argan oil and South African passionflower oil was the best when mixed in a ratio of 1:1.

[0067] The nanoliposomes prepared in Example 7 and Example 8 were measured for encapsulation efficiency based on conventional ultracentrifugation-ultraviolet spectrophotometry; first, a full-wavelength scan (200-400 nm) was performed for the mixed system of the two essential oil compounds and DES, and it was found that there was obvious absorption at 280 nm. The nanoliposomes were then added to sterilized water, fully mixed with ultrasound, and then placed in a centrifuge tube for ultracentrifugation; after centrifugation, the ultraviolet absorption of the supernatant at 280 nm originated from the unencapsulated essential oil compound-DES, while the ultraviolet absorption of the remainder at 280 nm originated from the encapsulated essential oil compound-DES, thereby determining the encapsulation efficiency of the nanoliposomes.

[0068] The results of the nanoliposome encapsulation efficiency test prepared in Example 7 and Example 8 are shown in the attached figure. Figure 2 As shown, it can be seen that the encapsulation efficiency of the two is above 99% and very close, which not only fully meets the application requirements, but also shows that the change of lecithin dosage will not significantly affect the encapsulation efficiency of nanoliposomes.

[0069] The nanoliposomes prepared in Example 8 were observed by scanning electron microscopy (SEM). During the operation, 100 μL of the nanoliposome aqueous suspension was mixed with 900 μL of PBS buffer to obtain a diluted sample. A drop of the prepared sample was dropped on a glass slide to complete gold plating. The microscopic observation results are shown in the attached figure. Figure 3 As shown, it can be seen that its shape is round and the edges are smooth.

[0070] The appearance of the liposome hydrogel patch based on African plant essential oil and deep eutectic solvent prepared in Example 10 and its fitting effect on the wrist skin are shown in the attached figure. Figure 4 As shown, the whole is in a transparent state, which is convenient for observing the body state and easy to fit; in addition, the cross-sectional SEM photo is shown in the attached Figure 5 As shown, there are no obvious bubbles, grooves, stratification or cracks, and the overall structure is relatively uniform.

[0071] The liposome hydrogel patch based on African plant essential oil and deep eutectic solvent prepared in Example 10 was tested by infrared spectroscopy. The results are shown in the attached figure. Figure 6As shown in the figure, the characteristic signals of essential oil components all appear in the patch; among them, 1658cm -1 The absorption peak at 1444 cm corresponds to the C=O group. -1 The absorption peaks at 1020 and 550 cm-1 correspond to those at CHOH. -1 The two peaks at correspond to the bending vibrations of NH and aromatic hydrogen, respectively, indicating that the essential oil has been successfully loaded.

[0072] Based on the method for determining the swelling degree of concentrated natural rubber latex and vulcanized latex in GB / T 14797.3-2008, the swelling property of the liposome hydrogel patch based on African plant essential oil and deep eutectic solvent prepared in Example 10 was evaluated. The specific operation was as follows:

[0073] The swelling test was performed gravimetrically. The dried sample was prepared into a 1-cm diameter disc, weighed, and immersed in 37°C PBS buffer (pH 7.4) for 1 to 7 hours. The sample was removed, centrifuged, and the residual surface moisture was removed with filter paper. The sample was weighed again. The experiment was repeated three times, and the results were recorded and averaged. The swelling ratio (SR, %) was calculated as follows: SR%=(m s -m d ) / m d ×100 where m s Mass of sample after swelling, m d is the mass of the sample before swelling.

[0074] The swelling test results of the above samples are shown in the attached Figure 7 It can be seen that this patch has the swelling property commonly found in hydrogels, which is consistent with the common characteristics of the latter.

[0075] Based on the T / SHRH022-2019 cosmetic moisturizing efficacy evaluation in vitro reconstructed 3D epidermal model test method, the moisturizing performance of the liposome hydrogel patch based on African plant essential oils and deep eutectic solvent prepared in Example 10 was evaluated. The specific procedures are as follows:

[0076] The dry sample was made into a disc sample with a diameter of 1 cm, immersed in ultrapure water until equilibrium was reached, and excess water on the surface was removed. The weight of the sample was measured and marked as W. eq Then store the sample in a 37℃ oven, weigh it at different intervals and record the results, perform the operation three times in parallel and take the average value; the moisture retention rate is calculated as follows: WR%=(W eq -W t ) / W eq ×100% Where W eq Represents the initial weight, W tRepresents the weight of the hydrogel at different time points within 1 to 8 hours.

[0077] The swelling test results of the above samples are shown in the attached Figure 8 It can be seen that this patch has the moisturizing properties that a skin care material should have, and will not cause the skin to lose water and dry out after being attached to the skin.

[0078] Based on GB / T6344-2008, the tensile strength and folding strength tests of the liposome hydrogel patch based on African plant essential oils and deep eutectic solvents prepared in Example 10 were conducted. The specific content and results are as follows:

[0079] The specific operation of the tensile strength test is to install the patch in a tensile testing machine and apply controllable stress until the hydrogel patch breaks. The results show that the tensile strength of this patch is ≥5N / 500g, and it has ideal toughness.

[0080] The specific operation of the folding strength test is to manually fold the hydrogel patch repeatedly at the same position until it breaks or visible cracks appear. The results show that the patch has good elasticity after being folded repeatedly for more than 10 times without any cracks.

Claims

1. A liposome hydrogel patch based on African plant essential oils and a deep eutectic solvent, characterized in that: First, nanoliposomes are prepared using African plant essential oils and low eutectic solvents as key components, and then the final product, a hydrogel patch, is obtained through cross-linking and gelation.

2. The liposome hydrogel patch based on African plant essential oil and deep eutectic solvent according to claim 1, characterized in that: The African plant essential oils include argan essential oil and South African passionflower essential oil, and the two African plant essential oils are compounded in a volume ratio of 2:1 to 1:2 and serve as functional substances of the liposome hydrogel patch.

3. The liposome hydrogel patch based on African plant essential oil and deep eutectic solvent according to claim 1, characterized in that: The low eutectic solvent used is composed of phytic acid and betaine, and the molar ratio of the two components is 3:1 to 1:

3. It serves as an essential oil solvent, a film-forming aid, a penetration enhancer and an auxiliary functional substance, and plays multiple roles at the same time.

4. The liposome hydrogel patch based on African plant essential oil and deep eutectic solvent according to claim 1, characterized in that: The compound of argan essential oil and South African passionflower essential oil is mixed with a phytic acid-betaine deep eutectic solvent in a volume ratio of 1:1 to 1:

2.

5. The liposome hydrogel patch based on African plant essential oil and deep eutectic solvent according to claim 1, characterized in that: Nanoliposomes were prepared by injection method, with the following specific steps: (1) dissolving soybean lecithin and cholesterol in a mixed solvent of ethanol and methanol to prepare a saturated lipid solution, wherein the mass ratio of the soybean lecithin to cholesterol is 1:1 to 1:2, and the volume ratio of the ethanol to methanol is 2:1 to 3:1; (2) a mixture of the above two African plant essential oils and a deep eutectic solvent was prepared into a saturated solution in phosphate PBS buffer as an aqueous medium, and heated to 60° C. in a water bath; (3) adding the aqueous medium obtained in step (2) dropwise to the lipid solution obtained in step (1), and then subjecting the entire system to ultrasonic dispersion, wherein the ultrasonic power is 300 to 500 W and the ultrasonic time is 10 to 20 min; removing the volatile solvent under reduced pressure, and standing at 4° C. to obtain a nanoliposome product.

6. The liposome hydrogel patch based on African plant essential oil and deep eutectic solvent according to claim 1, characterized in that: The obtained nanoliposomes are mixed with an aqueous solution of sodium alginate and bentonite, and then acrylamide, ammonium peroxide dicarboxylate and N,N,N',N'-tetramethylethylenediamine solution are added in sequence to form a transparent film patch through cross-linking and gelation. The specific steps are as follows: (1) Sodium alginate and ultrapure water were mixed at a mass ratio of 1:50 and stirred to obtain a clear sodium alginate solution. Bentonite and ultrapure water were then mixed at a mass ratio of 1:100, added to the sodium alginate aqueous solution, and stirred thoroughly in a 40°C water bath until the mixture was uniformly mixed. (2) adding the prepared nanoliposomes to the mixed solution in step (1) at a volume ratio of 1:100, and then adding acrylamide at a volume mass ratio of 1:7.5 (mL / g) to the nanoliposomes to the mixed solution and mixing thoroughly; (3) adding a 1 mg / mL N,N-methylenebisacrylamide aqueous solution at a volume mass ratio of 1:0.005 (mL / g) to the nanoliposomes to the mixed solution obtained in step (2), stirring thoroughly, adding a 10 mg / mL ammonium peroxide dicarboxylate aqueous solution at a volume mass ratio of 1:0.05 (mL / g) to the nanoliposomes and a 0.76 mg / mL N,N,N',N'-tetramethylethylenediamine aqueous solution at a volume mass ratio of 1:0.05-0.10 (mL / g), and crosslinking and gelation were carried out in a 60°C water bath for 0.5-1h; (4) Pour the reaction product obtained in step (3) into a mold while hot, cool and let it stand until it is completely formed, then open the film, dry it under reduced pressure at 50°C for 3 hours, sterilize it with ultraviolet light for 60 minutes, slice it, package it, and store it in a vacuum.

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