Eye protection patch and its preparation method and application

Abstract

The present invention discloses an eye patch and a preparation method and application thereof, belonging to the field of cosmetics. The eye patch is mainly composed of polyvinyl alcohol, polyethylene glycol, poly (N-isopropyl acrylamide), N,N'-methylene bis acrylamide, sodium dodecyl sulfate, an initiator combination, plant extracts, lutein, and hyaluronic acid, and is formed by a specific ratio and preparation process, and can control the release of plant extracts at body temperature.

Description

Technical Field

[0001] The invention belongs to the field of biomaterials and medical supplies, and specifically relates to an eye patch and a preparation method and application thereof, in particular to a hydrogel eye patch for eye care. Background Art

[0002] Eye care is an important part of personal care and beauty. With the accelerated pace of modern life, people are paying more and more attention to eye health and beauty. Existing eye care products on the market include eye creams, eye masks and eye massagers, which can relieve eye fatigue, improve dark circles and reduce eye puffiness to a certain extent. However, they usually have the following limitations:

[0003] Durability of Effect: The active ingredients in traditional eye care products may not work over time and require frequent use.

[0004] Penetration issues: The active ingredients in some eye care products have difficulty penetrating the surface layer of the skin, limiting their deep care effects.

[0005] In view of the above problems, researchers have been exploring new technologies for eye care that are safer, more effective and easier to use. In recent years, smart hydrogels, as a new type of material, have shown great potential in the fields of drug delivery, tissue engineering and wound dressing. In particular, temperature-sensitive hydrogels can responsively release encapsulated substances under conditions close to human body temperature, providing new design ideas for eye care products.

[0006] However, applying smart hydrogel technology to eye care products, especially in the form of eye patches, still faces challenges, such as how to ensure the biocompatibility and safety of hydrogels, how to achieve effective loading and controlled release of plant extracts, and how to ensure the comfort and fit of hydrogel eye patches.

[0007] The present invention aims to address the deficiencies of the prior art and provide a new type of intelligent temperature-controlled release hydrogel eye patch, which utilizes the synergistic effect of temperature-sensitive materials and plant extracts to provide users with a safe, effective and easy-to-use eye care solution. Summary of the invention

[0008] The invention provides an eye protection patch and a preparation method and application thereof, which can moisturize and soothe the skin through natural ingredients extracted from plants.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The present application provides an eye patch and a preparation method and application thereof. The eye patch is mainly composed of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly (N-isopropylacrylamide), N,N'-methylenebisacrylamide, an initiator composition, sodium dodecyl sulfate, a plant extract, lutein, and hyaluronic acid. It is formed by a specific ratio and preparation process and can control the release of the plant extract at 36-37°C.

[0011] The present invention provides a method for preparing the hydrogel eye patch, and the specific method is as follows:

[0012] A1: Add polyvinyl alcohol to deionized water, heat until completely dissolved, and then stir and cool to room temperature, add PEG to the cooled PVA solution and stir evenly; then dissolve poly(N-isopropylacrylamide) in deionized water, heat until completely dissolved, and then add the poly(N-isopropylacrylamide) solution to the PVA / PEG solution and stir evenly; wherein polyvinyl alcohol, polyethylene glycol, poly(N-isopropylacrylamide); mixing conditions: pH 6.0-7.5, temperature 25-35°C, mixing time 2-4h;

[0013] A2: Weigh N,N'-methylenebisacrylamide, initiator composition and sodium dodecyl sulfate, add to the mixed solution of A1, heat to 35-38°C, and stir for 1-4h.

[0014] A3: Add plant extracts, lutein and hyaluronic acid to A2 gel, and then stir for 1-2 hours at a stirring temperature of 37-38°C.

[0015] A4: Cool A3 to 20-25°C and rinse repeatedly with deionized water to obtain the target product.

[0016] In the present invention, poly(N-isopropylacrylamide), polyvinyl alcohol, polyethylene glycol, N,N'-methylenebisacrylamide, an initiator combination, a plant extract, lutein, and hyaluronic acid are used to form an eye patch that can control the release of plant extracts at body temperature through a specific ratio and preparation process. The specific principle is that below the critical solution temperature (LCST), which is 36-37°C in this application, the polymer remains in a swollen state, the drug cannot be released or the release rate is negligible, and when it is at or above the LCST, the hydrogel undergoes a phase change, shrinks, and changes the size of its voids, resulting in rapid release of the drug in the voids.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Temperature control: The temperature-sensitive material used in the hydrogel eye patch can undergo a phase change under conditions close to human body temperature, thereby achieving the controlled release of plant extracts and improving the targetedness and effectiveness of eye care.

[0019] High Loading: The hydrogel network structure provides high loading capacity for plant extracts. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : SEM structural diagram of Example 1 at 100μm (a), 40μm (b), 20μm (c), and 10μm (d) scales. DETAILED DESCRIPTION

[0021] In order to better understand the present invention, the present invention is further described below in conjunction with specific examples, wherein the terms used in the examples are for describing specific embodiments and do not constitute limitations on the scope of protection of the present invention.

[0022] The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. Unless otherwise specified, percentages and parts are calculated by weight.

[0023] Some raw materials and their sources are as follows:

[0024] Mung bean extract: purchased from Shanyang Lianfeng Biotechnology Co., Ltd.

[0025] Centella asiatica extract: purchased from Shanyang Lianfeng Biotechnology Co., Ltd.

[0026] Lutein: purchased from Aladdin Reagent (Shanghai) Co., Ltd.

[0027] Hyaluronic acid: purchased from Aladdin Reagent (Shanghai) Co., Ltd.

[0028] The chemical reagents used in the present invention were purchased from Aladdin Reagents (Shanghai) Co., Ltd.

[0029] Preparation, comprising the following steps:

[0030] Eye patch preparation process:

[0031] A1: Add polyvinyl alcohol to deionized water, heat until completely dissolved, and then stir and cool to room temperature, add PEG to the cooled PVA solution and stir evenly; then dissolve poly(N-isopropylacrylamide) in deionized water, heat until completely dissolved, and then add the poly(N-isopropylacrylamide) solution to the PVA / PEG solution and stir evenly for 2-4 hours; mixing conditions: pH 6.0-7.5, temperature 25-35°C;

[0032] A2: Weigh N,N'-methylenebisacrylamide, initiator composition and sodium dodecyl sulfate, add to the mixed solution of A1, heat to 35-38°C and stir for 0.5-1h.

[0033] A3: Add plant extracts, lutein, hyaluronic acid, etc. to A2 gel, and then stir for 1-2 hours at a stirring temperature of 37-38°C;

[0034] A4: Cool A3 to 20-25°C and rinse repeatedly with deionized water to obtain the target product.

[0035] Embodiment 1: Follow steps A1-A4; wherein the mass percentage of polyvinyl alcohol is 70%, the mass percentage of polyethylene glycol is 13%, the mass percentage of poly(N-isopropylacrylamide) is 4%, the mass percentage of N,N'-methylenebisacrylamide is 2%, the mass percentage of the initiator composition is 1.2%, the mass percentage of sodium dodecyl sulfate is 0.9%, the mass percentage of the plant extract is 1%, the mass percentage of lutein is 0.3%, and the mass percentage of hyaluronic acid is 0.3%; wherein the plant extract is mung bean extract; the initiator composition is ammonium persulfate and N,N,N',N'-tetramethylethylenediamine, wherein the mass fraction ratio of ammonium persulfate to N,N,N',N'-tetramethylethylenediamine is 1:3; A1 mixing conditions are pH 6.7, temperature 26°C, and time 2.7h; A2 condition parameters are temperature 37°C and stirring time 2h; A3 condition parameters are stirring 1.5h and stirring temperature 38°C.

[0036] Example 2: Follow steps A1-A4; wherein the mass percentage of polyvinyl alcohol is 65%, the mass percentage of polyethylene glycol is 15%, the mass percentage of poly(N-isopropylacrylamide) is 5%, the mass percentage of N,N'-methylenebisacrylamide is 3%, the mass percentage of the initiator composition is 2%, the mass percentage of sodium dodecyl sulfate is 0.5%, the mass percentage of the plant extract is 0.5%, the mass percentage of lutein is 0.5%, and the mass percentage of hyaluronic acid is 0.5%; wherein the plant extract is Centella asiatica extract; the initiator composition is ammonium persulfate and N,N,N',N'-tetramethylethylenediamine, wherein the mass fraction ratio of ammonium persulfate to N,N,N',N'-tetramethylethylenediamine is 1:4; A1 mixing conditions are pH 7.5, temperature 35°C, and time 2h; A2 condition parameters are temperature 38°C and stirring 1h; A3 condition parameters are stirring 1h and stirring temperature 37°C.

[0037] Example 3: Follow steps A1-A4; wherein the mass percentage of polyvinyl alcohol is 60%, the mass percentage of polyethylene glycol is 10%, the mass percentage of poly(N-isopropylacrylamide) is 3%, the mass percentage of N,N'-methylenebisacrylamide is 1%, the mass percentage of the initiator composition is 0.5%, the mass percentage of sodium dodecyl sulfate is 1.2%, the mass percentage of the plant extract is 2%, the mass percentage of lutein is 0.1%, and the mass percentage of hyaluronic acid is 0.1%; wherein the plant extract is mung bean extract; the initiator composition is ammonium persulfate and N,N,N',N'-tetramethylethylenediamine, wherein the mass fraction ratio of ammonium persulfate to N,N,N',N'-tetramethylethylenediamine is 1:2; A1 mixing conditions are pH 6.7, temperature 30°C, and time 4h; A2 condition parameters are temperature 37°C and stirring 4h; A3 condition parameters are stirring for 2h and stirring temperature 38°C.

[0038] Comparative Example 1: The difference from Example 1 is that the weight percentage of the raw materials used is 78% by weight of polyvinyl alcohol and 5% by weight of polyethylene glycol, and the remaining steps are the same as Example 1.

[0039] Comparative Example 2: The difference from Example 1 is that the percentage of sodium dodecyl sulfate used is 2%, and the remaining steps are the same as Example 1.

[0040] Comparative Example 3: The difference from Example 1 is that sodium lauryl sulfate is not added, and the remaining steps are the same as Example 1.

[0041] Comparative Example 4: The difference from Example 1 is that no poly(N-isopropylacrylamide) is added, and the rest is the same as Example 1.

[0042] In the above comparative example, the vacancies were replaced by deionized water of uniform quality.

[0043] Safety Test

[0044] With reference to the 2015 Technical Specifications for Safety of Cosmetics, the eye patches of Examples 1-3 were evaluated for cosmetic irritation. The test method was a skin patch test, and 30 randomly distributed people aged 16-65 years were tested.

[0045] Test method: Put the test substance into the patch tester, the dosage is 0.020-0.025g, cover the patch tester with the test substance on the back or forearm of the subject with non-irritating cloth-based tape, and gently press it with the palm to make it evenly adhere to the skin surface for 24 hours. After removing the test patch tester, observe the skin reaction after the indentation disappears 30 minutes later. If the result is negative, observe again 24 hours and 48 hours after the patch test.

[0046] Evaluation criteria:

[0047] Grade 0: negative reaction;

[0048] Grade 1: Suspicious reaction, only slight erythema;

[0049] Grade 2: weak positive reaction, erythema, infiltration, edema, and papules may be present;

[0050] Grade 3: Strong positive reaction, erythema, infiltration, edema, papules, and the reaction may extend beyond the test area;

[0051] Grade 4: Very strong positive reaction, obvious erythema, severe infiltration, edema, confluent herpes, and the reaction exceeds the test area.

[0052] Test results: Skin reactions were negative in all subjects.

[0053] The above test results show that the eye patch provided by the present invention is mild and non-irritating to the skin and is safe to use.

[0054] Encapsulation rate / release rate test

[0055] Accurately weigh the plant extract, lutein, and hyaluronic acid, dissolve them in water, mix them evenly, and use ultraviolet spectrophotometry to determine the lutein content in the aqueous solution at this time, record it as V1 (with lutein as the standard), and then follow steps A1-A4, and then combine the cleaning solution and the residual liquid in A4, determine the absorbance V2 (with lutein as the standard), and calculate the encapsulation rate based on V1 and V2.

[0056] The target product A4 is evenly divided into four parts E1, E2, E3, and E4, and E1, E2, E3, and E4 are placed in an aqueous solution, which is temperature-controlled (30°C, 36°C, 37°C, and 38°C) for 30 minutes, and the liquid is measured to obtain the lutein content X. According to the V package, X calculates the release rate.

[0057] Refer to the calculation formula: Packing rate Release rate

[0058] Table 1

[0059]

[0060]

[0061] The experimental results show that, by comparing the results of Example 1 to Example 3, it can be seen that the encapsulation rate is between 74% and 77%, the release rate is as high as 69.37%, and the release temperature is basically between 36 and 37°C.

[0062] Comparing Example 1 with Comparative Example 1, the encapsulation rate of Example 1 is significantly better than that of Comparative Example 1. This may be because the change in the feed ratio of polyvinyl alcohol to polyethylene glycol affects the strength of the gel. The increase in its strength leads to a tight texture, so that its voids are reduced, thereby affecting its encapsulation rate and release rate.

[0063] By comparing the results of Example 1 with Comparative Examples 2-3, it can be seen that the addition of sodium dodecyl sulfate has no significant effect on the encapsulation rate, but the amount of addition has a significant effect on the release temperature, and the amount of addition affects its temperature control critical point.

[0064] Comparing Example 1 with Comparative Example 2, the encapsulation rate of Example 1 is almost the same as that of Comparative Example 2, but the release temperature of Comparative Example 2 is significantly higher than 38°C, which is significantly higher than its usage scenario. Combined with its usage scenario, it is not practical.

[0065] Comparing Example 1 with Comparative Example 3, the encapsulation rate of the example is almost the same as that of Comparative Example 3, but the release temperature of Comparative Example 3 is significantly lower than 30°C, which is not conducive to the packaging, transportation, and storage of conventional commodities; out of considerations of practicality and transportation convenience, this solution is not selected as the preferred solution.

[0066] Comparing Example 1 with Comparative Example 4, the encapsulation efficiency of Example 1 is much higher than that of Comparative Example 4, which may be due to the lack of poly (N-isopropylacrylamide), resulting in a reduction in its internal voids, so that the encapsulation efficiency is lower than that of Example 1, and its release temperature is significantly lower than 30°C, so this scheme is not selected as the preferred scheme.

[0067] Subjective assessment test

[0068] Evaluate the effectiveness of eye patches in soothing, relieving fatigue, and reducing edema.

[0069] Test steps:

[0070] 1. Screen volunteers and select 30 people (half male and half female) who use their eyes frequently, such as copywriters and programmers. Randomly select 15 of them to use eye patches, and the other 15 to use placebo eye patches (pure gel, without plant extracts, lutein, or hyaluronic acid).

[0071] 2. Do not use other similar or similar products or make-up or skin care products before using the eye patch.

[0072] 3. The frequency of use is to apply the eye patch directly under the eyelid before going to bed every day. Be careful not to stick it on the root of the eyelashes to avoid affecting the effect. Apply it once a day for 30 minutes each time for 14 days. After each use, compare the fatigue, swelling and soothing effects before and after use, score and submit the score sheet after 14 days.

[0073] 4. Staff collected statistics, filtered out abnormal data, and calculated the average. The specific data is shown in Table 2

[0074] Table 2

[0075] Experimental Group Soothing (5 points) Relieve fatigue (5 points) Reduce swelling (5 points) Example 1 4.8** 4.5*** 4.1** Comfort Eye Patch 1.4 0.7 1.3

[0076] *(0.01<=p<0.05),**(0.001<=p<0.01),***(p<0.001)

[0077] The experimental results show that the eye patch prepared in the present application has the effects of soothing, relieving fatigue, and reducing edema.

[0078] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

Claims

1. A hydrogel eye patch, characterized in that: The hydrogel eye patch is made of the following raw materials in percentage by weight: Polyvinyl alcohol 60-70%; Polyethylene glycol 10-15%; Poly(N-isopropylacrylamide) 3-5%; N,N'-methylenebisacrylamide 1-3%; Initiator composition 0.5-2%; Sodium dodecyl sulfate 0.1-1.2% Plant extract 0.5-2%; Hyaluronic acid 0.1-0.5%; Lutein 0.1-0.5%; Make up the balance with water; The plant extract is at least one of mung bean extract and Centella asiatica extract; The initiator composition comprises ammonium persulfate and N,N,N',N'-tetramethylethylenediamine; the mass fraction ratio of the ammonium persulfate and N,N,N',N'-tetramethylethylenediamine is 1:2-4.

2. The hydrogel eye patch according to claim 1, characterized in that: The preparation method of the hydrogel eye patch comprises the following steps: A1: Mix polyvinyl alcohol, polyethylene glycol, and poly(N-isopropylacrylamide); mixing conditions: pH 6.0-7.5, temperature 25-35°C, time 2-4h; A2: Add N,N'-methylenebisacrylamide, initiator composition and sodium dodecyl sulfate to A1 to start polymerization reaction, followed by stirring; stirring time: 1-4h, stirring temperature: 35-38°C; A3: Add plant extract, lutein and hyaluronic acid to A2 gel, and then stir for 1-2 hours at a temperature of 37-38°C; A4: Cool A3 to 20-25°C to form a hydrogel eye patch.

3. The hydrogel eye patch according to any one of claims 1-2, characterized in that: The hydrogel eye patch can achieve controlled release of plant extracts, lutein, and hyaluronic acid at 36-37°C.

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