An environmentally friendly plant gum-containing cataplasm and its application

Abstract

The present invention belongs to the technical field of gel plaster preparation, and particularly relates to a gel plaster containing an environmentally friendly plant gum and its application. The present invention uses rice roots as raw materials to extract rice root plant gum, and uses the extracted rice root plant gum as a raw material to prepare a gel plaster, which can effectively increase the viscosity of the gel plaster and solve the problems of low viscosity and easy detachment of gel plasters in the prior art; at the same time, this gel plaster has no irritation and allergy to the skin. Secondly, the present invention makes full use of rice roots, turning waste into treasure and realizing resource recycling.

Description

Technical Field

[0001] The present invention belongs to the technical field of gel plaster preparation, and particularly relates to a gel plaster containing an environment-friendly plant gum and its application. Background Art

[0002] Gel plaster is a new dosage form developed based on traditional plasters by combining new excipients and modern technologies. Compared with traditional plasters, it has obvious advantages such as good air permeability, strong penetration, rapid transdermal absorption, being reusable without cold flow, and not easily staining clothes. However, at the present stage, there are still various problems to be solved in many aspects to promote the development of gel plasters. For example, some gel plaster varieties have poor viscoelasticity, poor skin followability, and are easy to fall off. Especially when gel plasters are used on joints, the above problems of gel plasters are more likely to be prominent.

[0003] Since the transdermal absorption of most transdermal drug delivery dosage forms is basically a rate-limiting process of the skin, the improvement of viscosity will affect the drug release performance of the paste to varying degrees, but will not have an obvious impact on the transdermal effect. To address the problem of poor viscoelasticity, new materials can be developed and combined with the preparation process to obtain the best formulation and process. At the same time, in the development of gel plasters, the development and application of new excipients play a decisive role. Based on this, in order to promote the development and optimization of gel plasters, it is crucial to develop domestic polymer materials and broaden the variety of matrix excipients for gel plasters according to market demand. Summary of the Invention

[0004] The purpose of the present invention is to provide a gel plaster containing an environment-friendly plant gum and its application. The gel plaster has good viscoelasticity, is not easy to fall off, has good skin followability, and has no irritation and allergy to the skin.

[0005] The present invention provides a rice root plant gum. The preparation method of the rice root plant gum includes the following steps: mixing rice root particles with water and heating, standing and filtering the obtained rice root solution to obtain a supernatant;

[0006] Mixing the supernatant with absolute ethanol and stirring until white flocculates precipitate to obtain the rice root plant gum.

[0007] Preferably, the mass-volume ratio of the rice root particles to water is 1 g:(15 - 25) mL; the particle size of the rice root particles is 65 - 100 mesh.

[0008] Preferably, the heating temperature is 60 - 90 °C, and the heating time is 1 - 3 h.

[0009] Preferably, the volume ratio of the absolute ethanol to the supernatant is (1 - 2):1.

[0010] The present invention also provides a method for preparing rice root plant gum, which comprises the following steps: mixing rice root particles with water and heating, standing and filtering the obtained solution to obtain a supernatant;

[0011] Mixing the supernatant with absolute ethanol and stirring until white flocculates precipitate to obtain the rice root plant gum.

[0012] The present invention also provides a gel plaster containing an environment-friendly plant gum, and the gel plaster comprises the rice root plant gum described in the above technical solution.

[0013] Preferably, the gel plaster further comprises partially neutralized sodium polyacrylate, aluminum glycinate, disodium edetate, tartaric acid, glycerol, water, polyvinylpyrrolidone and benzoic acid.

[0014] Preferably, by mass percentage, it comprises 0.3-3% of rice root plant gum, 4-8% of partially neutralized sodium polyacrylate, 0.05-0.5% of aluminum glycinate, 0.05-0.3% of disodium edetate, 0.1-0.6% of tartaric acid, 20-40% of glycerol, 50-70% of water, 0.2-2% of polyvinylpyrrolidone and 0.1-0.5% of benzoic acid.

[0015] Preferably, by mass percentage, it comprises 1.01% of rice root plant gum, 5.0% of partially neutralized sodium polyacrylate, 0.15% of aluminum glycinate, 0.1% of disodium edetate, 0.26% of tartaric acid, 35.68% of glycerol, 56.38% of water, 1.22% of polyvinylpyrrolidone and 0.2% of benzoic acid.

[0016] The present invention also provides the application of the rice root plant gum or the gel plaster described in the above technical solution in the preparation of plasters.

[0017] Beneficial effects:

[0018] The present invention provides a gel plaster containing an environment-friendly plant gum. The present invention uses rice roots as raw materials to extract rice root plant gum, and uses the extracted rice root plant gum as raw materials to prepare a gel plaster, which can effectively increase the viscosity of the gel plaster and solve the problems of low viscosity and easy detachment of the gel plaster in the prior art; at the same time, this gel plaster has no irritation and allergy to the skin.

[0019] Secondly, the present invention makes full use of rice roots, turning waste into treasure and realizing resource recycling. Brief description of the drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments.

[0021] Figure 1 Schematic diagram for initial adhesion force measurement;

[0022] Figures 2-1 to 2-3 For the initial adhesion force measurement diagram in Example 17, where Figure 2-1 is Sample No. ①, Figure 2-2 is Sample No. ②, Figure 2-3 is Sample No. ③;

[0023] Figure 3 is the schematic diagram of the holding adhesion force measurement;

[0024] Figures 4-1 to 4-2 For the result diagram of the single-dose skin irritation experiment, where Figure 4-1 is the control group, Figure 4-2 is the gel plaster group prepared in Example 15;

[0025] Figures 5-1 to 5-2 For the result diagram of the multiple-dose skin irritation experiment, where Figure 5-1 is the control group, Figure 5-2 is the gel plaster group prepared in Example 15;

[0026] Figures 6-1 to 6-3 For the result diagram of the skin allergy experiment, where 6-1 is the blank control group, Figure 6-2 is the test drug group, Figure 6-3 is the positive control group. Detailed implementation method

[0027] The present invention provides a rice root plant gum, and the preparation method of the rice root plant gum includes the following steps: Mix rice root particles with water and then heat, let the obtained rice root solution stand and filter to obtain a supernatant; Mix the supernatant with absolute ethanol and stir until white flocculates precipitate to obtain the rice root plant gum.

[0028] The present invention mixes rice root particles with water and then heats to obtain a rice root solution. Before mixing the rice root particles with water, the present invention preferably further includes pulverizing the rice roots to obtain rice root particles. The present invention has no special limitation on the pulverizing method and process, and conventional pulverizing methods in the art can be used. The particle size of the rice root particles of the present invention is preferably 65-100 mesh, more preferably 65-80 mesh, and even more preferably 80 mesh. The mass-volume ratio of the rice root particles to water of the present invention is preferably 1 g:(15-25) mL, more preferably 1 g:(15-20) mL, and even more preferably 1 g:20 mL. The heating temperature of the present invention is preferably 60-90 °C, more preferably 70-80 °C, and even more preferably 70 °C; the heating time is preferably 1-3 h, more preferably 2-3 h, and even more preferably 2 h.

[0029] After obtaining the rice root solution, the present invention allows the rice root solution to stand and filter to obtain a supernatant. The standing in the present invention is preferably overnight. The present invention has no special limitation on the filtering method, and conventional filtering methods in the art can be used.

[0030] After obtaining the supernatant, the present invention mixes the supernatant with absolute ethanol and stirs until white flocculates precipitate to obtain the rice root plant gum. The volume ratio of the absolute ethanol to the supernatant in the present invention is preferably (1-2):1, more preferably 1.5:1. The present invention preferably pours the absolute ethanol into the supernatant, and more preferably slowly pours the absolute ethanol into the supernatant while stirring; the way of pouring the absolute ethanol into the supernatant has the effect of uniformly precipitating white flocculates. After stirring until white flocculates precipitate, the present invention preferably further includes centrifugation to obtain white flocculates. The present invention has no special limitation on the centrifugation method, and conventional centrifugation methods in the art can be used.

[0031] After obtaining the white flocculates, the present invention preferably further includes drying and pulverizing the white flocculates to obtain the rice root plant gum. The present invention preferably flattens the white flocculates before drying. The drying temperature in the present invention is preferably 40-60°C, more preferably 50°C. The drying time is preferably 4-6h, more preferably 5h. The present invention has no special limitation on the pulverization process, and conventional pulverization steps in the art can be used. The particle size of the rice root plant gum after pulverization is preferably 80-120 mesh, more preferably 100 mesh.

[0032] The preparation raw material of the rice root plant gum in the present invention is the unwanted roots of rice, realizing waste utilization and resource recycling; the rice root plant gum obtained by using the preparation method and parameters of the present invention has stronger viscosity, improving its utilization value.

[0033] The present invention also provides a preparation method of rice root plant gum, including the following steps: mixing rice root particles with water and heating, allowing the obtained solution to stand and filter to obtain a supernatant; mixing the supernatant with absolute ethanol and stirring until white flocculates precipitate to obtain the rice root plant gum. The preparation method of the rice root plant gum in the present invention is the same as that in the above technical solution, and will not be elaborated here.

[0034] The present invention also provides a gel plaster containing an environment-friendly plant gum, and the gel plaster includes the rice root plant gum described in the above technical solution. The rice root plant gum in the present invention can increase the viscosity of the gel plaster, solving the problems of low viscosity and easy detachment of the existing gel plaster.

[0035] The gel plaster in the present invention preferably further includes partially neutralized sodium polyacrylate, glyceryl aluminum hydroxide, disodium edetate, tartaric acid, glycerol, water, polyvinylpyrrolidone and benzoic acid.

[0036] In terms of mass percentage, the gel patch of the present invention preferably comprises 0.3-3% rice root plant gum, more preferably 0.71-1.32%, and even more preferably 1.01%. The rice root plant gum of the present invention can increase the viscosity of the gel patch.

[0037] The gel patch of the present invention preferably comprises 4-8% partially neutralized sodium polyacrylate, more preferably 3.5-6.5%, and even more preferably 5.0%. The partially neutralized sodium polyacrylate of the present invention has the function of forming a gel skeleton matrix.

[0038] The gel patch of the present invention preferably comprises 0.05-0.5% aluminum glycol hydroxide, more preferably 0.1-0.2%, and even more preferably 0.15%. The aluminum glycol hydroxide of the present invention acts as a cross-linking agent.

[0039] The gel patch of the present invention preferably comprises 0.05-0.3% edetate disodium, more preferably 0.07-0.13%, and even more preferably 0.1%.The edetate disodium of the present invention has the function of a chelating agent.

[0040] The gel patch of the present invention preferably comprises 0.1-0.6% tartaric acid, more preferably 0.18-0.34%, and even more preferably 0.26%.The tartaric acid of the present invention has the function of regulating pH.

[0041] The gel patch of the present invention preferably comprises 20-40% glycerol, more preferably 35.68%. The glycerol of the present invention has the effect of moisturizing the gel patch.

[0042] The gel patch of the present invention preferably comprises 50-70% water, more preferably 56.38%. The gel patch of the present invention preferably comprises 0.2-2% povidone, more preferably 1.22%; the povidone acts as an adhesive.

[0043] The gel patch of the present invention preferably comprises 0.1-0.5% benzoic acid, more preferably 0.1-0.3%, and even more preferably 0.2%.

[0044] The present invention uses rice root plant gum, partially neutralized sodium polyacrylate, aluminum glyoxylate, disodium edetate, tartaric acid, glycerin, water, povidone, and benzoic acid as raw materials to prepare a gel patch. The raw materials are simple and easily available. By rationally controlling the mass fractions of the raw materials, the prepared gel patch is more viscous than conventional gel patches, has no adhesive residue, has good skin-adherence, can be repeatedly removed, and improves the user experience of the patch.

[0045] The present invention also provides a method for preparing the above-mentioned hydrogel patch, which includes the following steps: Dissolve tartaric acid, disodium edetate, and benzoic acid in water to obtain Phase A; Disperse rice root gum, partially neutralized sodium polyacrylate, glycohydroxyaluminum, and povidone in glycerol to obtain Phase B; Mix Phase A and Phase B to obtain a hydrogel paste; Coat the hydrogel paste on non-woven fabric, cover it with a film, and let it stand at room temperature to obtain the hydrogel patch.

[0046] In the present invention, tartaric acid, disodium edetate, and benzoic acid are dissolved in water to obtain Phase A. There is no special limitation on the dissolution method in the present invention, and the conventional dissolution method in the art can be used.

[0047] In the present invention, rice root gum, partially neutralized sodium polyacrylate, glycohydroxyaluminum, and povidone are dispersed in glycerol to obtain Phase B. After dispersing the rice root gum, partially neutralized sodium polyacrylate, glycohydroxyaluminum, and povidone in glycerol, it is preferably further included to fully mix the above components. There is no special limitation on the mixing method in the present invention, and the conventional mixing method in the art can be used.

[0048] After obtaining Phase A and Phase B, in the present invention, Phase A and Phase B are mixed to obtain a hydrogel paste. Preferably, Phase B is added to Phase A in the present invention to better transfer the liquid and prevent the liquid from splashing due to the transfer. The hydrogel paste in the present invention is preferably a hydrophilic hydrogel paste.

[0049] After obtaining the hydrogel paste, in the present invention, the hydrogel paste is coated on non-woven fabric, covered with a film, and left to stand at room temperature to obtain the hydrogel patch. The film in the present invention is preferably a polyethylene film. The time for standing at room temperature in the present invention is preferably 3 to 7 days, more preferably 5 days. There is no special limitation on the amount of the hydrogel paste coated on the non-woven fabric in the present invention, and the amount of the hydrogel paste can be adjusted according to actual production needs.

[0050] The present invention also provides the application of the rice root gum or the hydrogel patch described in the foregoing technical solution in the preparation of a plaster.

[0051] In order to further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but they cannot be understood as limiting the protection scope of the present invention.

[0052] Example 1

[0053] A kind of rice root gum is prepared by the following preparation steps:

[0054] The rice roots were crushed by a pulverizer to a particle size of 80 mesh. The rice root powder was taken, and distilled water was added according to a solid-liquid ratio (g / mL) of 1:20. The mixture was stirred evenly, heated at 70 °C for 2 h, allowed to stand, filtered, and the supernatant was taken. 1.5 times the volume of anhydrous ethanol of the supernatant was slowly poured into the supernatant while stirring to precipitate white flocculants. After centrifugation, the white flocculants were taken out, flattened, dried at 50 °C, and pulverized to obtain rice root plant gum.

[0055] Examples 2-3, Comparative Examples 1-2

[0056] The rice root plant gum was prepared using the preparation steps in Example 1, except that the particle sizes of the rice root powder in Examples 2-3 and Comparative Examples 1-2 were 65 mesh, 100 mesh, 50 mesh, and 120 mesh in sequence.

[0057] The extraction rates of the rice root plant gum obtained by using the preparation methods in Examples 1-3 and Comparative Examples 1-2 were calculated. The calculation formula was: rice root plant gum extraction rate = amount of rice root plant gum / amount of rice root powder × 100%

[0058] The extraction rates of the rice root plant gum in Examples 1-3 and Comparative Examples 1-2 were 3.6%, 3.1%, 3.0%, 2.6%, and 2.4% in sequence.

[0059] Examples 4-5, Comparative Examples 3-4

[0060] The rice root plant gum was prepared using the preparation steps in Example 1, except that the solid-liquid ratios (g / mL) of the rice root powder to water in Examples 4-5 and Comparative Examples 3-4 were 1:15, 1:25, 1:10, and 1:30 in sequence.

[0061] The extraction rates of the rice root plant gum in Examples 4-5 and Comparative Examples 3- were 2.7%, 3.1%, 1.5%, and 2.5% in sequence.

[0062] Examples 6-8, Comparative Examples 5-6

[0063] The rice root plant gum was prepared using the preparation steps in Example 1, except that the heating temperatures in Examples 6-8 and Comparative Examples 5-6 were 60 °C, 80 °C, 90 °C, 40 °C, and 50 °C.

[0064] The extraction rates of the rice root plant gum in Examples 6-8 and Comparative Examples 5-6 were 2.9%, 3.4%, 3.2%, 0.9%, and 1.6% in sequence.

[0065] Examples 9-12, Comparative Example 7

[0066] Examples 9 to 12 and Comparative Example 7 prepared the rice root plant gum using the preparation steps in Example 1, except that the heating time in Examples 9 to 12 and Comparative Example 7 was 1 h, 1.5 h, 2.5 h, 3 h, and 0.5 h.

[0067] The extraction rates of the rice root plant gum in Examples 9 to 12 and Comparative Example 7 were 2.5%, 2.7%, 3.2%, 3.2%, and 1.3% in sequence.

[0068] Examples 13 to 15 and Comparative Example 8

[0069] Examples 13 to 15 and Comparative Example 8 prepared the rice root plant gum using the preparation steps in Example 1, except that the volume ratio of anhydrous ethanol to the supernatant in Examples 13 to 15 and Comparative Example 8 was 1, 1.2, 2, and 0.8 in sequence.

[0070] The extraction rates of the rice root plant gum in Examples 13 to 15 and Comparative Example 8 were 2.7%, 2.9%, 3.1%, and 2.1% in sequence.

[0071] Example 16

[0072] A gel plaster containing an environment-friendly plant gum is composed of the following components:

[0073] 1.01% rice root plant gum, 5.0% partially neutralized sodium polyacrylate, 0.15% glycollate aluminum, 0.1% disodium edetate, 0.26% tartaric acid, 35.68% glycerol, 56.38% water, 1.22% povidone, and 0.2% benzoic acid.

[0074] Specifically: 11.5 g of rice root plant gum, 56.8 g of partially neutralized sodium polyacrylate, 1.7 g of glycollate aluminum, 1.1 g of disodium edetate, 3 g of tartaric acid, 405 g of glycerol, 640 g of water, 13.8 g of povidone, and 2.3 g of benzoic acid.

[0075] The preparation method consists of the following steps: Dissolve the prescription amounts of tartaric acid, disodium edetate, and benzoic acid in water as Phase A; Disperse the rice root plant gum, partially neutralized sodium polyacrylate, glycollate aluminum, and povidone together in glycerol, and mix well to form Phase B; Add Phase B to Phase A, mix well, and then obtain a hydrophilic gel paste. Coat it on a non-woven fabric and simultaneously cover it with a polyethylene film, and it can be used after standing at room temperature for 3 to 7 days.

[0076] Example 17

[0077] Select the main matrix, rice root plant gum, partially neutralized sodium polyacrylate, glycollate aluminum, tartaric acid, and povidone for optimization. The test method is according to the orthogonal design table L

[0074] , 5 ,

[0077] ,

[0076] ,

[0075] , , , 16 , , (4 5)Arrange the experiment as shown in Table 2 "Factor-Level Table". The contents of other components for preparing the gel patch remain unchanged in each test, specifically 1.1 g of disodium edetate, 405 g of glycerol, 640 g of water, and 2.3 g of benzoic acid. The parameters of the preparation method were optimized with the comprehensive sensory evaluation score as the inspection index, and the specific requirements for the sensory score are shown in Table 1. The results are shown in Table 3 "Orthogonal Test Results".

[0078] Table 1 Specific requirements for comprehensive sensory score

[0079]

[0080]

[0081] Note: For the corresponding sensory scores, "very good" is 10 points, "normal" is 8 points, "average" is 6 points, "poor" is 5 points, "very poor" is 3 points, and "no such property" is 0 points.

[0082] Table 2 Factor-Level Table

[0083]

[0084] Table 3 Orthogonal Test Results

[0085]

[0086]

[0087] It can be seen from the results in Table 3 that A2B1C2D3E4 is the combination with a higher score, and the largest range difference is in rice root plant gum, partially neutralized sodium polyacrylate, and glyceryl aluminum hydroxide, that is, the components that have the greatest impact on the process are rice root plant gum, partially neutralized sodium polyacrylate, and glyceryl aluminum hydroxide.

[0088] Example 17

[0089] Determination of the adhesion of the gel patch

[0090] The adhesion of the gel patch containing rice root plant gum (No. ①) prepared in Example 16, the gel patch without plant gum (No. ②), and the commercially available plaster (No. ③) is as follows:

[0091] 1) Determination of tack

[0092] The determination method of tack refers to the first method in the Determination of Adhesion Method 0952 in the General Principles of the Chinese Pharmacopoeia 2020 Edition.

[0093] Before the test, place the experimental plaster (together with the packaging material) at 18 - 25°C and relative humidity of 40% - 70% for more than 2 hours. Scrub the surface of the inclined plate and the stainless steel ball with a wiping material dipped in anhydrous ethanol, and carefully dry it with a clean dust-free cloth. Repeat the cleaning process more than 3 times until the surfaces of the inclined plate and the stainless steel ball are visually inspected to be clean.

[0094] Adjust the inclined plate to an inclination angle of 15°C as required. Take 3 pieces of each of the above-mentioned plasters ① - ③ respectively, and fix the back lining of the test sample on the inclined plate with double-sided tape. The upper end of the test sample should be located at the lower line position of the horizontal line of the inclined plate, with the sticky surface facing up and the experimental length along the inclined plane not exceeding 5 cm. The test sample should be evenly attached to the plate. Place steel balls of different weights at the upper line position of the horizontal line and let them freely fall from the inclined plane, and record the ball number of the largest steel ball that each test sample can stick to; the schematic diagram for the determination of initial adhesiveness is as Figure 1 shown.

[0095] Result judgment: Among the steel balls stuck by each of the 3 test samples of each type, if all 3 are the ball numbers of the largest steel balls, or 2 are the ball numbers of the largest steel balls and the other steel ball number is only one number smaller, it meets the requirements; if one is the ball number of the largest steel ball and the other two steel ball numbers are only one number smaller, then another three pieces should be taken for retest, and if all 3 can stick to the steel ball with the largest ball number, it meets the requirements. The test results are as Figures 2-1 to 2-3 and shown in Table 4:

[0096] Table 4 Record of Initial Adhesiveness Determination

[0097]

[0098] Note: ① - 1, ① - 2, and ① - 3 represent three replicates of plaster ①, and the same applies to others, which will not be elaborated further.

[0099] From Table 4 and Figures 2-1 to 2-3 it can be concluded that: The largest steel ball that plaster ① (gel plaster prepared in Example 15) can stick to is No. 19, which is the largest among the steel ball numbers stuck by the 3 experimental samples. The largest steel ball that plaster ③ can stick to is No. 7, which is the smallest among the steel ball numbers stuck by the 3 experimental samples, indicating that the gel plaster containing plant gum has better initial adhesiveness.

[0100] 2) Determination of holding adhesiveness

[0101] The determination method of holding adhesiveness refers to the second method in Appendix 0952 Adhesion Determination Method in the Chinese Pharmacopoeia 2020 Edition.

[0102] Stick the sticky surface of the test sample on the surface of the test plate, place it vertically, and hang a weight of a specified mass along the length direction of the test sample, and record the time when the test sample slips until it falls off or the distance of displacement within a certain time.

[0103] Before the test, the experimental plaster (together with the packaging material) should be placed at 18 - 25°C and relative humidity of 40% - 70% for more than 2 hours.

[0104] Wipe the test plate and loading plate with a wiping material dipped in anhydrous ethanol, and carefully dry it with a clean dust-free cloth. Repeat the cleaning process more than 3 times until the surfaces of the test plate and loading plate are visually inspected to be clean. After cleaning, the test plate and loading plate should not be touched by hand or other objects. Take 3 pieces of the above-mentioned plasters ① - ③ respectively, and stick the test samples parallel to the longitudinal direction of the plate in the middle of the adjacent test plate and loading plate. Roll a roller back and forth over the test sample three times. After the test sample is stuck on the plate, let it stand at room temperature for 20 minutes, fix it on the test rack, and record the starting time or position of the test. The schematic diagram of the holding force measurement is as Figure 3 shown.

[0105] Result judgment: The displacement amount or the peeling time should comply with the regulations under each variety item. The test result is expressed as the arithmetic mean of the displacement amount or the peeling time of a group of test samples. The results are shown in Table 5.

[0106] Table 5 Record of Holding Force Measurement

[0107]

[0108] It can be seen from Table 5 that the displacement distance of Plaster No. ①, i.e., the gel plaster containing plant gum, after testing is 5.3 mm, which is the smallest among the 3 experimental samples, indicating that the gel plaster containing plant gum has better holding force.

[0109] 3) Irritation test

[0110] The irritation of the gel plaster prepared in Example 16 was measured, and a control group was set up. The control group was a gel plaster without rice root plant gum, and the contents of other components were the same as those in Example 16.

[0111] 3.1 Single-dose rabbit intact skin irritation test

[0112] Take 3 New Zealand rabbits (2 - 2.5 kg). 24 hours before dosing, depilate the skin on both sides of the spine of the rabbits, divide it into 4 parts, and the area of each depilated part is about 3 cm × 3 cm. Check whether the depilated skin is damaged due to depilation before dosing. Rabbits with damaged skin are not suitable for the test. Stick a blank matrix and a gel plaster containing plant gum on the depilated part of each experimental animal respectively, and fix them with non-irritating adhesive tape. 24 hours after dosing, wash the drug clean with warm water. Observe and record the presence of erythema, edema, etc. at the drug application site, and the recovery of the above changes at 1, 24, 48, and 72 hours after drug removal.

[0113] 3.2 Multiple-dose Skin Irritation Test in Rabbits with Intact Skin

[0114] Select 3 New Zealand rabbits (2 - 2.5 kg). Twenty-four hours before drug administration, depilate the skin on both sides of the spine of the rabbits, divide it into 4 parts, and the area of each depilated part is about 3 cm × 3 cm. Check whether the depilated skin is damaged before the experiment. Rabbits with damaged skin are not suitable for the experiment. Apply blank matrix and gel plaster containing plant gum to each rabbit respectively, and fix them with non-irritating tape. Twenty-four hours after drug administration, wash the residual drug with warm water, and continue to apply the drug 1 hour later. Repeat the above steps, apply the drug continuously for 3 days, once a day for 24 hours each time, and observe at the same time. Twenty-four hours after the third drug administration, wash the drug clean with warm water, and observe and record whether there are erythema, edema and other conditions at the drug application site, as well as the recovery of the above changes at 1, 24, 48 and 72 hours after drug removal.

[0115] 3.3 Evaluation Criteria

[0116] Score according to the "Skin Irritation Reaction Scoring" and "Skin Irritation Intensity Evaluation" methods in the "Technical Guidelines for the Study of Irritation and Hemolysis of Traditional Chinese Medicines and Natural Medicines", calculate the average integral of the irritation reaction according to the formula: Average integral of each group of animals = Total integral of erythema and edema / Number of test animals, and conduct an evaluation of the irritation intensity. The scoring criteria for skin irritation reaction and the evaluation criteria for skin irritation intensity are shown in Tables 6 - 7 respectively.

[0117] Table 6 Scoring Criteria for Skin Irritation Reaction

[0118]

[0119] Table 7 Evaluation Criteria for Skin Irritation Intensity

[0120]

[0121] 3.4 Experimental Results

[0122] The results of the single-dose skin irritation experiment are shown in Table 8 and Figure 4-1 and Figure 4-2 as shown

[0123] Table 8 Skin Reaction Integral Values in the Single-dose Test on Intact Skin

[0124]

[0125]

[0126] From Table 8 and Figures 4-1 to 4-2It can be concluded that in the single-dose administration test of the hydrogel patch prepared in Example 16, no phenomena such as erythema and edema were observed in the tested area of the intact skin on the back of New Zealand rabbits at 1, 24, 48, and 72 hours after drug removal. That is, in the single-dose administration test on the intact skin of New Zealand rabbits, the hydrogel patch containing rice root gum did not show obvious irritating effects on the skin of New Zealand rabbits.

[0127] The results of the multiple-dose administration skin irritation test are shown in Tables 9-10 and Figure 5-1 and Figure 5-2 as follows.

[0128] Table 9 Cumulative values of skin reactions in the multiple-dose administration test on intact skin

[0129]

[0130] Table 10 Average integral values of skin reactions and irritation intensity in the multiple-dose administration test on intact skin

[0131]

[0132]

[0133] From Tables 9-10 and Figure 5-1 and Figure 5-2 it can be seen that in the multiple-dose administration test of the hydrogel patch prepared in Example 16, no phenomena such as erythema and edema were observed in the tested area of the intact skin on the back of New Zealand rabbits at 24 hours after the first and second administrations and at 1, 24, 48, and 72 hours after drug removal. That is, in the multiple-dose administration test on the intact skin, the hydrogel patch containing rice root gum did not show obvious irritating effects on the skin of New Zealand rabbits.

[0134] 4) Hypersensitivity test

[0135] The hydrogel patch prepared in Example 16 was used as the tested drug group for hypersensitivity test determination, and a blank control group and a positive control group were designed. In the blank control group, except for the absence of rice root gum, the other components were the same as those in Example 16; the positive control group was 1% 2,4-dinitrochlorobenzene.

[0136] Nine guinea pigs (220±10 g) were taken and divided into 3 groups, with 3 in each group, namely the tested drug group, the positive control group, and the blank control group. 24 hours before the test, the hair on the symmetric two sides of their backs was removed, and the hair removal area on each side was 3 cm×3 cm, and the following test was carried out.

[0137] 4.1 Sensitizing contact

[0138] On the left depilated areas of the above three groups of animals, apply a blank matrix, a gel patch containing rice root gum, and 0.2 mL of a positive sensitizer (1% 2,4-dinitrochlorobenzene). After administration to the positive control group, cover it with a layer of sterilized oil paper and two layers of sterilized gauze, and fix with adhesive tape. The contact time lasts for 6 hours, and repeat the above administration process on the 7th and 14th days after administration.

[0139] 4.2 Provocative contact

[0140] On the 14th day after the last administration in the sensitization contact stage, repeat the above administration process. The administration site is the right depilated area, and the concentration of the positive sensitizer is 0.2 mL of 1% 2,4-dinitrochlorobenzene. Wash off the drug 6 hours after provocation, observe immediately, and then observe the skin allergic reaction again at 24, 48, and 72 hours. Evaluate according to the scoring criteria in the "Technical Guidelines for the Study of Immunotoxicity (Allergic and Photoallergic Reactions) of Traditional Chinese Medicines and Natural Medicines".

[0141] Average value of allergic reaction = (total score of erythema formation + total score of edema formation) / total number of animals Incidence of sensitization = number of animals with erythema, edema or systemic allergic reaction / total number of animals

[0142] *Note: The number of animals with erythema, edema or systemic allergic reaction should be counted regardless of the severity.

[0143] The scoring criteria for the degree of skin allergic reaction and the evaluation criteria for skin lethality are shown in Tables 11 - 12.

[0144] Table 11 Scoring criteria for the degree of skin allergic reaction

[0145]

[0146] Table 12 Evaluation criteria for skin sensitization

[0147]

[0148] 4.4 During the experiment, no severe systemic allergic reactions such as asthma, unsteady standing or shock occurred in each group of animals. The specific experimental results are as Figures 6-1 to 6-3 shown.

[0149] It can be Figures 6-1 to 6-3 concluded that: the average scores of the sensitization reactions in the positive control group at 0 h, 24 h, 48 h and 72 h were 1.35, 3.7, 4, 5, and the sensitization rate was 100%. The average values of the sensitization reactions in the blank control group and the test drug group were both 0, and the sensitization rate was 0%. There was no skin allergy or edema formation in the gel patch group containing rice root gum and the blank matrix control group.

[0150] It can be concluded from the above embodiments that the gel patch containing rice root plant gum of the present invention has good overall formability, and the prepared gel patch has relatively good initial adhesion and lasting adhesion. It is generally shown that the gel patch containing rice root plant gum of the present invention has high viscosity, good skin followability, is not easy to fall off, and can be repeatedly peeled and used, which solves the problem of low viscosity of gel patches in the industry. In addition, the results of skin allergy and irritation experiments show that the gel patch containing rice root plant gum has no allergy or irritation to the skin, has better breathability, and is safer to use.

[0151] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A gel plaster containing an environment-friendly plant gum, characterized in that, The gel plaster comprises 0.3 - 3% of rice root plant gum; The preparation method of the rice root plant gum comprises the following steps: mixing rice root particles with water and heating, standing and filtering the obtained rice root solution to obtain a supernatant; Mixing the supernatant with absolute ethanol, stirring until white flocculates precipitate, centrifuging to obtain white flocculates, drying and pulverizing the white flocculates to obtain the rice root plant gum; The particle size of the rice root plant gum is 80 - 120 mesh; The particle size of the rice root particles is 80 mesh; The mass - volume ratio of the rice root particles to water is 1 g:20 mL; The temperature of the heating is 70 °C; the time of the heating is 2 h; The volume ratio of the absolute ethanol to the supernatant is 1.5:

1.

2. The hydrogel patch according to claim 1, wherein The gel plaster further comprises partially neutralized sodium polyacrylate, aluminum glycinate, disodium edetate, tartaric acid, glycerol, water, polyvinylpyrrolidone and benzoic acid.

3. The hydrogel patch according to claim 2, wherein, By mass percentage, it comprises 0.3 - 3% of rice root plant gum, 4 - 8% of partially neutralized sodium polyacrylate, 0.05 - 0.5% of aluminum glycinate, 0.05 - 0.3% of disodium edetate, 0.1 - 0.6% of tartaric acid, 20 - 40% of glycerol, 50 - 70% of water, 0.2 - 2% of polyvinylpyrrolidone and 0.1 - 0.5% of benzoic acid.

4. The hydrogel patch according to claim 3, wherein By mass percentage, it comprises 1.01% of rice root plant gum, 5.0% of partially neutralized sodium polyacrylate, 0.15% of aluminum glycinate, 0.1% of disodium edetate, 0.26% of tartaric acid, 35.68% of glycerol, 56.38% of water, 1.22% of polyvinylpyrrolidone and 0.2% of benzoic acid.

5. Use of the gel plaster according to any one of claims 1 - 4 in the preparation of a plaster.

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