An eczema external washing formula and a preparation method thereof

Abstract

The application relates to the technical field of traditional Chinese medicine preparations, and specifically discloses a wet eczema external washing formula and a preparation method thereof. The wet eczema external washing formula is composed of three raw medicinal materials, namely, Sophora flavescens, Fructus Mume and Smilax glabra. The preparation method is as follows: low-temperature segmented extraction of Fructus Mume is performed to obtain an acidic extract and residues; a part of the acidic extract is used to pretreat the residues, and then enzymolysis is performed to obtain a directional polysaccharide extract; the remaining acidic extract is used to extract Sophora flavescens and Smilax glabra; the extract and the polysaccharide extract are combined at a controlled speed to construct a non-covalent compound; after nitrogen protection, segmented concentration and low-temperature curing and shaping, the product is obtained through filling, sterilization and the like. The wet eczema external washing formula can be used for wet eczema external washing treatment, active ingredients can form a sustained-release colloid network, the skin residence time is prolonged, and the antipruritic and anti-inflammatory effects are long-lasting. In the preparation method, no exogenous acid and alkali and no chemical stabilizer need to be introduced, resource closed-loop utilization in the formula is realized, the dissolution rate of active ingredients and the stability of the preparation are high, the process controllability is good, and the preparation method is suitable for industrialized production.

Description

Technical Field

[0001] This application relates to the field of traditional Chinese medicine preparation technology, and more specifically, it relates to an external wash formula for eczema and its preparation method. Background Technology

[0002] Eczema is a common inflammatory skin disease characterized by recurrent flare-ups and intense itching, severely impacting patients' quality of life. Topical herbal soaks are a common treatment for eczema, as the medication acts directly on the affected skin, avoiding the first-pass effect of oral administration. This method offers advantages such as rapid onset of action and minimal systemic side effects, and is widely used in clinical practice. With the increasing incidence of eczema and patients' growing demands for medication safety, developing simple, safe topical eczema washes is of significant clinical importance.

[0003] Existing traditional Chinese medicine (TCM) external wash formulas for eczema generally employ a multi-herb compound formulation. To cover the complex pathogenesis of eczema, multiple heat-clearing, dampness-drying, wind-dispelling, and itch-relieving herbs are often used in combination. Some preparations also introduce exogenous excipients such as synthetic acids and alkalis and chemical stabilizers during the preparation process. This formulation and process design results in a complex and diverse composition of the preparation, increasing the possibility of drug sensitization. For eczema patients with impaired skin barrier function, especially children and people with sensitive constitutions, this can easily cause skin irritation or allergic reactions, limiting the safety of long-term use. Summary of the Invention

[0004] To address the issues that existing traditional Chinese medicine eczema wash preparations have complex ingredients, are prone to causing skin irritation or allergic reactions, and lack safety with long-term use, this application provides an eczema wash formula and its preparation method.

[0005] Firstly, this application provides a topical wash for eczema, employing the following technical solution: A topical wash for eczema, made solely from the following raw materials in parts by weight: 18-22 parts Sophora flavescens, 16-26 parts Prunus mume, and 15-25 parts Smilax glabra.

[0006] By adopting the above technical solution, the alkaloids contained in Sophora flavescens can inhibit the release of inflammatory mediators and exert a direct anti-inflammatory and antipruritic effect; the organic acids contained in Prunus mume can regulate the local acid-base environment of the skin lesions and astringe the damaged skin; and the flavonoids contained in Smilax glabra can scavenge local free radicals and exert a detoxifying and dampness-removing effect. The combination of the three can cover the core pathogenesis of eczema, while significantly reducing the types of ingredients in the preparation and reducing the risk of allergies caused by the superposition of multiple ingredients.

[0007] Preferably, the raw materials are in the following proportions by weight: 20 parts Sophora flavescens, 20 parts Prunus mume, and 20 parts Smilax glabra.

[0008] By adopting the above technical solution, the content ratio of active ingredients of each raw material is appropriate under this ratio, which can form a stable intermolecular interaction system. At the same time, the material balance matching degree with the subsequent preparation process is optimal, ensuring the uniformity of product quality between batches.

[0009] Secondly, this application provides a method for preparing an external wash for eczema, using the following technical solution: A method for preparing an external wash for eczema includes the following steps: S1. Low-temperature segmented extraction: Take the prescribed amount of dried plum, crush it, add purified water, first extract it at low temperature, then heat it to a gentle boil and boil it, and filter it to obtain the acidic extract of dried plum and the dried plum residue. S2, Directed enzymatic hydrolysis of medicinal residue: Take part of the acidic extract of dried plum obtained from S1 and add it to the dried plum residue. After adjusting the pH, pretreat at low temperature, then add compound enzyme for enzymatic hydrolysis. After the enzymatic hydrolysis is completed, inactivate the enzyme and filter to obtain dried plum polysaccharide extract. S3, Acidic Relay Extraction: Take the prescribed amount of Sophora flavescens and Smilax glabra, add the remaining acidic extract of Prunus mume obtained in S1, first keep warm for extraction, then heat to a gentle boil and decoct, filter to obtain the acidic extract of Sophora flavescens and Smilax glabra. S4. Controlled-rate merging and construction: Cool the extract obtained in S3, and slowly add the plum polysaccharide extract obtained in S2 while stirring. After the addition is complete, continue stirring to obtain the merging liquid. S5. Nitrogen-protected concentration: Transfer the combined liquid obtained in S4 into a concentration tank, introduce nitrogen and maintain positive pressure, and avoid light throughout the process. First, perform high-temperature rapid concentration to 40%-50% of the original volume, and then perform low-temperature slow concentration to 1.0-1.5g of total raw drug per milliliter of liquid to obtain the concentrated liquid. S6. Low-temperature curing and shaping: The concentrated solution obtained in S5 is left to stand and cure, so that the non-covalent complexes formed in the solution are arranged in a regularized manner through molecular thermal motion, forming a weakly cross-linked colloidal network precursor. Then, it is filled and sterilized to obtain the finished product.

[0010] By adopting the above technical solution, a closed-loop utilization system for medicinal resources was constructed. Different components of ume were used as extraction solvents, enzymatic hydrolysis regulators, and functional excipients, respectively. No exogenous acids, alkalis, or chemical stabilizers were introduced throughout the process. While achieving efficient extraction of active ingredients, a colloidal drug delivery system with sustained-release effect was constructed, improving the comprehensive utilization rate of medicinal materials.

[0011] Preferably, in step S1, the amount of purified water added is 6-10 times the weight of the dried plum, the temperature of the low-temperature extraction is 50-60℃ and the time is 30-45 min, the time of the gentle boiling decoction is 1-1.5 h, the pH value of the resulting acidic extract of dried plum is 2.8-4.0, and it is refrigerated at 2-8℃ for later use.

[0012] By adopting the above technical solution, low-temperature extraction can preferentially dissolve small-molecule water-soluble organic acid components in dried plums, avoiding the premature dissolution of large-molecule pectin due to high temperature, preventing filtration difficulties and loss of active ingredients due to pectin encapsulation during subsequent extraction, and gentle boiling can further extract the remaining phenols and other effective components in dried plums, ensuring that the acidity of the acidic extract meets the requirements of subsequent processes.

[0013] Preferably, in step S2, the pH is adjusted to 3.5-4.0, the compound enzyme is composed of cellulase and pectinase in a mass ratio of 1:0.5-1:1.5, and the amount added is 0.2%-0.5% of the weight of the dried plum residue. The initial pH of the enzymatic hydrolysis is 4.5-5.5, the temperature is 45-55℃, and the enzyme inactivation condition is 85-95℃ for 10-20 minutes.

[0014] By adopting the above technical solution, the pH of the enzymatic hydrolysis system can be adjusted by using the acidic extract of dried plum itself, thus avoiding the residual risk caused by the introduction of exogenous acid. The acidic pretreatment can destroy the lignin structure of the cell wall of dried plum residue, making it easier for the compound enzyme to contact the substrate and improve the enzymatic hydrolysis efficiency. The compound enzyme with a specific ratio can specifically decompose the cellulose and pectin components in the cell wall and release polysaccharide components with suitable viscosity and moisturizing properties in a targeted manner.

[0015] Preferably, in step S3, the temperature of the heat preservation extraction is 60-70℃ and the time is 30-40 min, the time of the gentle boiling decoction is 1-1.5 h, the pH value of the filtered Sophora flavescens-Smilax glabra acidic extract is 3.2-3.6, the filter residue is added with acidic solution or purified water and extracted again 1-2 times, and the filtrates are combined.

[0016] By adopting the above technical solution, gradient heating extraction can achieve differentiated dissolution of active ingredients with different thermal stability. First, heat preservation extraction can reduce the high-temperature degradation of flavonoid glycosides in Smilax glabra, and then gentle boiling decoction can fully extract alkaloids in Sophora flavescens. The acidic extraction environment can make alkaloids form salts to improve their water solubility, while inhibiting the hydrolysis of flavonoid glycosides and improving the chemical stability of active ingredients.

[0017] Preferably, in step S4, the temperature is lowered to 40-45°C, the stirring speed is 100-150 r / min, the slow addition time is controlled at 15-20 min, and the stirring time is 10-15 min.

[0018] By adopting the above technical solution, the temperature range is suitable for the stable formation of intermolecular hydrogen bonds. Slow feeding and low-speed stirring can avoid the aggregation phenomenon caused by excessive local concentration of polysaccharides, so that matrine, astilbene and plum polysaccharide can be uniformly combined to form a well-dispersed non-covalent complex, reduce the skin irritation of matrine, and improve its transdermal retention ability.

[0019] Preferably, in step S5, the nitrogen positive pressure is 0.02-0.05 MPa, the high-temperature rapid concentration temperature is 70-80℃ and the vacuum degree is -0.08 to -0.09 MPa, the low-temperature slow concentration temperature is 55-65℃ and the vacuum degree is -0.07 to -0.08 MPa, and after concentration, potassium sorbate or sodium benzoate is added as a preservative at a concentration of 0.05%-0.2% of the total volume of the concentrate.

[0020] By adopting the above technical solutions, nitrogen positive pressure can isolate oxygen and prevent the polyphenolic components in the drug solution from undergoing oxidation and polymerization. The complete avoidance of light can further prevent the degradation of photosensitive components. The segmented concentration process first removes most of the water at a higher temperature, shortening the total heating time, and then completes the concentration at a lower temperature, protecting the heat-sensitive active ingredients and the already formed non-covalent complex structure, thus balancing production efficiency and product quality.

[0021] Preferably, in step S6, the temperature for static curing is 35-45℃ and the time is 12-24h, and the sterilization method is 100-105℃ flowing steam sterilization for 30-34min.

[0022] By adopting the above technical solution, low-temperature static curing can enable the initially formed non-covalent complex to be regularly arranged through molecular thermal motion, forming a uniformly structured weakly cross-linked colloidal network precursor, improving the storage stability of the formulation, avoiding stratification and precipitation during long-term storage, and the flow-through steam sterilization conditions are mild and will not damage the structure of the active ingredients or the integrity of the colloidal network, while ensuring the sterility level of the product.

[0023] Thirdly, this application provides a method for using an external wash for eczema, employing the following technical solution: A method for using an eczema external wash: Take the concentrated solution prepared from the eczema external wash, dilute it 10-20 times with warm water at 40-45℃, let it stand for 5-10 minutes to activate it in situ, so that the colloidal network precursor spontaneously absorbs water, swells and is evenly dispersed into a slow-release colloidal network, and then soak or apply it to the affected area 1-2 times a day for 15-20 minutes each time.

[0024] By adopting the above technical solution, dilution with warm water can change the ionic strength and concentration of the system, triggering the colloidal network precursor to spontaneously absorb water and swell, forming a slow-release colloid with a three-dimensional network structure. This colloid can adhere to the skin surface to form a protective film, reducing the impact of external stimuli on skin lesions, while slowly releasing active ingredients and prolonging the duration of efficacy.

[0025] In summary, this application has the following beneficial effects: 1. Because this application uses a minimally simplistic formula consisting only of Sophora flavescens, Prunus mume, and Smilax glabra, and employs a segmented gradient process that utilizes acidic relay extraction of polysaccharides from the medicinal residues to achieve directional enrichment and intermolecular synergistic construction, the formula is significantly simplified while achieving efficient extraction and synergistic effects of active ingredients. This effectively reduces the risk of sensitization associated with multi-herb compound formulas and chemical additives. 2. In this application, the acidic extract of dried plum is preferred as the extraction solvent and enzymatic pretreatment agent. There is no need to introduce exogenous acid to adjust the pH. This not only improves the dissolution rate and stability of active ingredients such as matrine and astilbene, but also directionally enriches functional polysaccharides of specific molecular weights and reduces chemical residues.

[0026] 3. The method of this application promotes the formation of non-covalent complexes by slowly adding polysaccharide extract at a controlled rate, and combines it with a low-temperature static ripening process after concentration, so that the complex is arranged in a regular manner to form a weakly cross-linked colloidal network precursor, thereby achieving the continuous and slow release of active ingredients and prolonging the drug's residence time on the skin.

[0027] 4. In this application, a segmented temperature-controlled concentration process under nitrogen protection is preferred. First, high-temperature rapid dehydration is carried out to shorten the total heating time, and then low-temperature fine concentration is carried out to protect the heat-sensitive components and non-covalent complex structure. At the same time, oxygen is isolated throughout the process to prevent polyphenol oxidation, thereby improving the long-term stability of the formulation.

[0028] 5. The method of use of this application involves diluting with warm water and then activating it in situ, allowing the colloidal network precursor to spontaneously absorb water and swell to form a uniform sustained-release colloidal network. This method achieves continuous drug delivery without the need for additional excipients, is easy to operate, has a gentle feel on the skin, and is suitable for long-term use. Attached Figure Description

[0029] Figure 1 This is a flowchart of a method for preparing an external wash for eczema provided in this application; Figure 2 This is a comparison chart of the 180-day accelerated stability test results of the various embodiments provided in this application and the comparative example; Figure 3 This is a complete comparison chart of skin irritation indices between the embodiments and comparative examples provided in this application; Figure 4 This is a comparison chart of the skin irritation index of the various embodiments and comparative examples provided in this application. Detailed Implementation

[0030] The present application will be further described in detail below with reference to embodiments and comparative examples. Unless otherwise specified, the experimental methods used below are conventional methods. Unless otherwise specified, the materials, reagents, methods and instruments used are all conventional materials, reagents, methods and instruments in the art, which can be obtained by those skilled in the art through commercial channels or prepared according to literature methods.

[0031] Technical Concept: Topical herbal soaks are a common clinical treatment for eczema. Current techniques generally employ a multi-herb compound formulation, layering various heat-clearing, dampness-drying, wind-dispelling, and itch-relieving herbs to cover the complex pathogenesis of eczema. Some preparations also introduce exogenous excipients such as synthetic acids and alkalis and chemical stabilizers during the preparation process. This technical approach originates from the traditional Chinese medicine concept of "multi-method synergy" in formulation. However, it is limited by the low dissolution rate of active ingredients in conventional extraction processes, which can only ensure efficacy by increasing the number of herbs. This results in highly complex formulations, significantly increasing the probability of skin irritation and allergic reactions for eczema patients with already compromised skin barrier function, especially children and people with sensitive constitutions, thus limiting the long-term safe use of the formulations.

[0032] This technical solution addresses the aforementioned issues by first identifying three core medicinal materials—Sophora flavescens, Prunus mume, and Smilax glabra—through efficacy screening to construct a simplified formula, significantly reducing the number of ingredients in the preparation. Simultaneously, it establishes a closed-loop resource utilization system within the formula, using organic acids obtained from the segmented extraction of Prunus mume as a natural acidic extraction solvent to improve the dissolution rate and stability of Sophora flavescens alkaloids and Smilax glabra flavonoids. Furthermore, it utilizes polysaccharides obtained from the enzymatic hydrolysis of Prunus mume residue as a natural functional excipient. Through controlled-rate merging and low-temperature maturation processes, the active ingredients and polysaccharides form non-covalent complexes and weakly cross-linked colloidal network precursors. The entire process requires no introduction of exogenous acids, alkalis, or chemical stabilizers, ensuring therapeutic efficacy while fundamentally reducing the risk of sensitization in the preparation.

[0033] Example 1: This example provides a topical wash for eczema, which contains the following ingredients in parts by weight: 20 parts Sophora flavescens, 20 parts Prunus mume, and 20 parts Smilax glabra.

[0034] The preparation method of the above-mentioned external wash for eczema includes the following steps: S1. Low-temperature segmented extraction: Take the prescribed amount of dried plum, crush it, add purified water, first extract at low temperature, then heat to a gentle boil and decoct, filter to obtain the acidic extract of dried plum and the dried plum residue.

[0035] The process involves crushing the dried plums to a particle size of 2mm to 5mm, adding purified water at a ratio of 8 times the weight of the dried plums, using a low-temperature extraction temperature of 55℃ for 37.5 minutes, and a gentle boiling time of 1.25 hours. The mixture is then filtered while hot using a 200-mesh filter cloth. The resulting acidic extract of the dried plums has a pH of 3.4 and is stored at 5℃ for later use.

[0036] S2, Directed Enzymatic Hydrolysis of Residue: Take a portion of the acidic extract of dried plum obtained in S1 and add it to the dried plum residue. After adjusting the pH, pretreat at low temperature, then add a compound enzyme for enzymatic hydrolysis. After the enzymatic hydrolysis is completed, inactivate the enzyme and filter to obtain dried plum polysaccharide extract.

[0037] The process involved adding 6.5% of the total weight of acidic extract of dried plum to adjust the pH of the system to 3.75, pretreatment at 42.5℃ for 25 minutes, and adding a compound enzyme composed of cellulase and pectinase in a 1:1 mass ratio at 0.35% of the weight of the dried plum residue. The initial pH of the enzymatic hydrolysis was adjusted to 5.0, the temperature was 50℃, the stirring speed was 100 r / min, and the hydrolysis time was 1.5 h. The enzyme was then inactivated by heating to 90℃ and holding for 15 minutes. The mixture was then filtered while hot using a 200-mesh filter cloth. The resulting dried plum polysaccharide extract contained 75% polysaccharides with a molecular weight of 10 kDa to 30 kDa.

[0038] S3, Acidic Relay Extraction: Take the prescribed amount of Sophora flavescens and Smilax glabra, add the remaining acidic extract of Prunus mume obtained in S1, first keep warm for extraction, then heat to a gentle boil and decoct, and filter to obtain the acidic extract of Sophora flavescens and Smilax glabra.

[0039] Sophora flavescens and Smilax glabra were cleaned and cut into thin slices with a thickness of 1 mm to 2 mm. They were mixed evenly. If the amount of acidic liquid was insufficient to cover the surface of the herbs, purified water was added until it covered the surface of the herbs by 2 cm. The extraction temperature was kept at 65℃ for 35 min, and the simmering time was 1.25 h. The mixture was filtered through a 200-mesh filter cloth. The residue was then extracted again with an equal amount of purified water. The two filtrates were combined, and the pH value of the resulting acidic extract of Sophora flavescens and Smilax glabra was 3.4.

[0040] S4. Controlled-rate merging and construction: Cool the extract obtained in S3, and slowly add the plum polysaccharide extract obtained in S2 while stirring. After the addition is complete, continue stirring to obtain the merged liquid.

[0041] The extract was cooled to 42.5℃, and the stirring speed was 125r / min. The extract of ume polysaccharide was slowly added using a constant flow pump, and the addition time was controlled at 17.5min. After the addition was completed, stirring was continued for 12.5min to ensure that the components were fully mixed.

[0042] S5. Nitrogen-protected concentration: Transfer the combined liquid obtained in S4 into a concentration tank, introduce nitrogen and maintain positive pressure, and avoid light throughout the process. First, perform high-temperature rapid concentration to 45% of the original volume, and then perform low-temperature slow concentration until each milliliter of liquid contains 1.25g of total raw medicinal material, to obtain the concentrated liquid.

[0043] The concentration tank is a jacketed vacuum concentration tank. Nitrogen gas is introduced to replace the air in the tank three times to maintain a nitrogen positive pressure of 0.035 MPa. The concentration tank is wrapped with black light-blocking cloth throughout the process. The high-temperature rapid concentration temperature is 75℃ and the vacuum degree is -0.085 MPa. The low-temperature slow concentration temperature is 60℃ and the vacuum degree is -0.075 MPa. After concentration, potassium sorbate is added as a preservative at 0.125% of the total volume of the concentrate. The mixture is stirred at 80 r / min for 5 min to ensure uniform mixing.

[0044] S6. Low-temperature curing and shaping: The concentrated solution obtained in S5 is left to stand and cure, so that the non-covalent complexes formed in the solution are arranged in a regularized manner through molecular thermal motion, forming a weakly cross-linked colloidal network precursor. Then, it is filled and sterilized to obtain the finished product.

[0045] The concentrate is transferred to a jacketed stainless steel curing tank and cured at 40°C for 18 hours. After curing, it is filled into sterile high-density polyethylene plastic bottles, 250 mL per bottle, and sterilized with flowing steam at 102°C for 32 minutes. After sterilization, it is naturally cooled to room temperature.

[0046] The application method of the eczema external wash in this embodiment is as follows: take the concentrated solution and dilute it 15 times with warm water at 42.5℃, let it stand for 7.5 minutes to activate it in situ, so that the colloidal network precursor formed in the finished product spontaneously absorbs water and swells and is evenly dispersed into a slow-release colloidal network. Then soak or apply wet compresses to the affected area twice a day for 17.5 minutes each time.

[0047] Example 2: This example provides a topical wash for eczema, which contains the following ingredients in parts by weight: 18 parts Sophora flavescens, 16 parts Prunus mume, and 15 parts Smilax glabra.

[0048] The preparation method of the above-mentioned external wash for eczema includes the following steps: S1. Low-temperature segmented extraction: Take the prescribed amount of dried plum, crush it, add purified water, first extract at low temperature, then heat to a gentle boil and decoct, filter to obtain the acidic extract of dried plum and the dried plum residue.

[0049] The process involves crushing the dried plums to a particle size of 2mm to 5mm, adding purified water at a ratio of 6 times the weight of the dried plums, using a low-temperature extraction temperature of 50℃ for 30 minutes, followed by a gentle boiling decoction for 1 hour, filtering while hot using a 200-mesh filter cloth, and obtaining an acidic extract with a pH of 2.8, which is then refrigerated at 2℃ for later use.

[0050] S2, Directed Enzymatic Hydrolysis of Residue: Take a portion of the acidic extract of dried plum obtained in S1 and add it to the dried plum residue. After adjusting the pH, pretreat at low temperature, then add a compound enzyme for enzymatic hydrolysis. After the enzymatic hydrolysis is completed, inactivate the enzyme and filter to obtain dried plum polysaccharide extract.

[0051] The process involved adding 5% of the total weight of acidic extract of dried plum to adjust the pH of the system to 3.5, pretreatment at 40℃ for 20 minutes, and adding a compound enzyme composed of cellulase and pectinase at a mass ratio of 1:0.5, which was 0.2% of the weight of the dried plum residue. The initial pH of the enzymatic hydrolysis was adjusted to 4.5, the temperature was 45℃, the stirring speed was 80 r / min, and the hydrolysis time was 1 hour. The enzyme was then inactivated by heating to 85℃ and holding for 10 minutes. The solution was filtered while hot using a 200-mesh filter cloth. The resulting dried plum polysaccharide extract contained 72% polysaccharides with a molecular weight of 10kDa to 30kDa.

[0052] S3, Acidic Relay Extraction: Take the prescribed amount of Sophora flavescens and Smilax glabra, add the remaining acidic extract of Prunus mume obtained in S1, first keep warm for extraction, then heat to a gentle boil and decoct, and filter to obtain the acidic extract of Sophora flavescens and Smilax glabra.

[0053] Sophora flavescens and Smilax glabra were cleaned and cut into thin slices with a thickness of 1 mm to 2 mm. They were mixed evenly. If the amount of acidic liquid was insufficient to cover the surface of the herbs, purified water was added until it covered the surface of the herbs by 2 cm. The extraction temperature was kept at 60℃ for 30 min, and the decoction time was 1 h. The mixture was filtered through a 200-mesh filter cloth. The residue was then extracted once again with an equal amount of purified water. The two filtrates were combined. The pH value of the resulting acidic extract of Sophora flavescens and Smilax glabra was 3.2.

[0054] S4. Controlled-rate merging and construction: Cool the extract obtained in S3, and slowly add the plum polysaccharide extract obtained in S2 while stirring. After the addition is complete, continue stirring to obtain the merged liquid.

[0055] The extract was cooled to 40°C, and the stirring speed was 100 r / min. The extract of ume polysaccharide was slowly added using a constant flow pump, and the addition time was controlled at 15 min. After the addition was completed, stirring was continued for 10 min to ensure that the components were fully mixed.

[0056] S5. Nitrogen-protected concentration: Transfer the combined liquid obtained in S4 into a concentration tank, introduce nitrogen and maintain positive pressure, and avoid light throughout the process. First, perform high-temperature rapid concentration to 40% of the original volume, and then perform low-temperature slow concentration until each milliliter of the liquid contains 1.0g of total raw medicinal material, to obtain the concentrated liquid.

[0057] The concentration tank is a jacketed vacuum concentration tank. Nitrogen gas is introduced to replace the air in the tank three times to maintain a nitrogen positive pressure of 0.02 MPa. The concentration tank is wrapped with black light-blocking cloth throughout the process. The high-temperature rapid concentration temperature is 70℃ and the vacuum degree is -0.09 MPa. The low-temperature slow concentration temperature is 55℃ and the vacuum degree is -0.08 MPa. After concentration, sodium benzoate is added as a preservative at 0.05% of the total volume of the concentrate. The mixture is stirred at 80 r / min for 5 min to ensure uniform mixing.

[0058] S6. Low-temperature curing and shaping: The concentrated solution obtained in S5 is left to stand and cure, so that the non-covalent complexes formed in the solution are arranged in a regularized manner through molecular thermal motion, forming a weakly cross-linked colloidal network precursor. Then, it is filled and sterilized to obtain the finished product.

[0059] The concentrate is transferred to a jacketed stainless steel curing tank and cured at 35°C for 12 hours. After curing, it is filled into sterile high-density polyethylene plastic bottles, 250 mL per bottle, and sterilized with flowing steam at 100°C for 30 minutes. After sterilization, it is naturally cooled to room temperature.

[0060] The application method of the eczema external wash in this embodiment is as follows: take the concentrated solution and dilute it 10 times with 40℃ warm water, let it stand for 5 minutes to activate it in situ, so that the colloidal network precursor formed in the finished product spontaneously absorbs water and swells and is evenly dispersed into a slow-release colloidal network. Then soak or apply wet compress to the affected area once a day for 15 minutes each time.

[0061] Example 3: This example provides a topical wash for eczema, containing the following ingredients in parts by weight: 22 parts Sophora flavescens, 26 parts Prunus mume, and 25 parts Smilax glabra.

[0062] The preparation method of the above-mentioned external wash for eczema includes the following steps: S1. Low-temperature segmented extraction: Take the prescribed amount of dried plum, crush it, add purified water, first extract at low temperature, then heat to a gentle boil and decoct, filter to obtain the acidic extract of dried plum and the dried plum residue.

[0063] The process involves crushing the dried plums to a particle size of 2mm to 5mm, adding purified water at a ratio of 10 times the weight of the dried plums, using a low-temperature extraction temperature of 60℃ for 45 minutes, followed by a gentle boiling and simmering time of 1.5 hours. The mixture is then filtered while hot using a 200-mesh filter cloth. The resulting acidic extract of the dried plums has a pH of 4.0 and is stored at 8℃ for later use.

[0064] S2, Directed Enzymatic Hydrolysis of Residue: Take a portion of the acidic extract of dried plum obtained in S1 and add it to the dried plum residue. After adjusting the pH, pretreat at low temperature, then add a compound enzyme for enzymatic hydrolysis. After the enzymatic hydrolysis is completed, inactivate the enzyme and filter to obtain dried plum polysaccharide extract.

[0065] The process involved adding 8% of the total weight of acidic extract of dried plum to adjust the pH of the system to 4.0, pretreatment at 45℃ for 30 minutes, and adding a compound enzyme composed of cellulase and pectinase at a mass ratio of 1:1.5, which was 0.5% of the weight of the dried plum residue. The initial pH of the enzymatic hydrolysis was adjusted to 5.5, the temperature was 55℃, the stirring speed was 120 r / min, and the hydrolysis time was 2 hours. The enzyme was then inactivated by heating to 95℃ and holding for 20 minutes. The solution was filtered while hot using a 200-mesh filter cloth. The resulting dried plum polysaccharide extract contained 78% polysaccharides with a molecular weight of 10 kDa to 30 kDa.

[0066] S3, Acidic Relay Extraction: Take the prescribed amount of Sophora flavescens and Smilax glabra, add the remaining acidic extract of Prunus mume obtained in S1, first keep warm for extraction, then heat to a gentle boil and decoct, and filter to obtain the acidic extract of Sophora flavescens and Smilax glabra.

[0067] Sophora flavescens and Smilax glabra were cleaned and cut into thin slices with a thickness of 1 mm to 2 mm. They were mixed evenly. If the amount of acidic liquid was insufficient to cover the surface of the herbs, purified water was added until it covered the surface of the herbs by 2 cm. The extraction temperature was 70℃ and the time was 40 min. The decoction time was 1.5 h. The mixture was filtered through a 200-mesh filter cloth. The residue was then extracted twice with an equal amount of purified water. The three filtrates were combined. The pH value of the resulting acidic extract of Sophora flavescens and Smilax glabra was 3.6.

[0068] S4. Controlled-rate merging and construction: Cool the extract obtained in S3, and slowly add the plum polysaccharide extract obtained in S2 while stirring. After the addition is complete, continue stirring to obtain the merged liquid.

[0069] The extract was cooled to 45°C, and the stirring speed was 150 r / min. The extract of ume polysaccharide was slowly added using a constant flow pump, and the addition time was controlled at 20 min. After the addition was completed, stirring was continued for 15 min to ensure that the components were fully mixed.

[0070] S5. Nitrogen-protected concentration: Transfer the combined liquid obtained in S4 into a concentration tank, introduce nitrogen and maintain positive pressure, and avoid light throughout the process. First, perform high-temperature rapid concentration to 50% of the original volume, and then perform low-temperature slow concentration until each milliliter of the liquid contains 1.5g of total raw medicinal material, to obtain the concentrated liquid.

[0071] The concentration tank is a jacketed vacuum concentration tank. Nitrogen gas is introduced to replace the air in the tank three times to maintain a nitrogen positive pressure of 0.05 MPa. The concentration tank is wrapped with black light-blocking cloth throughout the process. The high-temperature rapid concentration temperature is 80℃ and the vacuum degree is -0.08 MPa. The low-temperature slow concentration temperature is 65℃ and the vacuum degree is -0.07 MPa. After concentration, potassium sorbate is added as a preservative at 0.2% of the total volume of the concentrate. The mixture is stirred at 80 r / min for 5 min to ensure uniform mixing.

[0072] S6. Low-temperature curing and shaping: The concentrated solution obtained in S5 is left to stand and cure, so that the non-covalent complexes formed in the solution are arranged in a regularized manner through molecular thermal motion, forming a weakly cross-linked colloidal network precursor. Then, it is filled and sterilized to obtain the finished product.

[0073] The concentrate is transferred to a jacketed stainless steel curing tank and cured at 45°C for 24 hours. After curing, it is filled into sterile high-density polyethylene plastic bottles, 250 mL per bottle, and sterilized with flowing steam at 105°C for 34 minutes. After sterilization, it is naturally cooled to room temperature.

[0074] The application method of the eczema external wash in this embodiment is as follows: take the concentrated solution and dilute it 20 times with 45℃ warm water, let it stand for 10 minutes to activate it in situ, so that the colloidal network precursor formed in the finished product spontaneously absorbs water and swells and is evenly dispersed into a slow-release colloidal network. Then soak or apply wet compresses to the affected area twice a day for 20 minutes each time.

[0075] Comparative Example 1: The preparation method of this comparative example adopts the conventional decoction method, that is, 20 parts of Sophora flavescens, 20 parts of Prunus mume and 20 parts of Smilax glabra are mixed and then purified water with 8 times the total weight of the medicinal materials is added. The mixture is heated to a gentle boil and decocted for 1.25 hours. The extract is filtered, and the residue is decocted again with 8 times the amount of purified water. The filtrates are combined and concentrated under normal pressure to a total raw drug content of 1.25g per milliliter. The mixture is then bottled and sterilized. The rest is the same as in Example 1.

[0076] Comparative Example 2: The only difference between this comparative example and Example 1 is that in step S3, an equal amount of purified water was used instead of the remaining acidic extract of Prunus mume obtained in S1 as the extraction solvent to extract Sophora flavescens and Smilax glabra. The rest is the same as in Example 1.

[0077] Comparative Example 3: The only difference between this comparative example and Example 1 is that step S2 is omitted, the dregs of the dried plum are directly discarded, the dried plum polysaccharide extract is not added in step S4, and the acidic extract of Sophora flavescens and Smilax glabra obtained in S3 is directly concentrated in the subsequent process. The rest is the same as Example 1.

[0078] Comparative Example 4: The only difference between this comparative example and Example 1 is that in step S4, the plum polysaccharide extract obtained in S2 is quickly poured into the extract obtained in S3 in one go, the addition time is less than 1 minute, and the mixture is stirred for 5 minutes to make it evenly mixed. The rest is the same as Example 1.

[0079] Comparative Example 5: The only difference between this comparative example and Example 1 is that the low-temperature static curing process in step S6 is omitted, and the product is directly filled and sterilized after concentration in S5. The rest is the same as Example 1.

[0080] Comparative Example 6: This comparative example used commercially available compound berberine liquid ointment. The affected area was soaked or wet-compressed according to the method specified in the product instructions, twice a day, for 17.5 minutes each time.

[0081] Experiment 1: Dissolution rate of active ingredients and stability of formulations were tested according to the General Chapter 0512 of the 2020 edition of the Chinese Pharmacopoeia, Part IV, and the Guidelines for Stability Testing of Raw Materials and Formulations, General Chapter 9001. Samples prepared in Examples 1-3 and Comparative Examples 1-6 were tested respectively. Appropriate amounts of each sample were taken, and the contents of matrine, oxymatrine, astilbin, and ursolic acid were determined by high-performance liquid chromatography. The chromatographic conditions were as follows: octadecylsilane-bonded silica gel as the stationary phase; gradient elution of acetonitrile-0.1% phosphoric acid aqueous solution as the mobile phase; dual-wavelength switching between 220 nm and 280 nm; flow rate 1.0 mL / min; column temperature 30℃; and injection volume 10 μL. Accelerated stability tests were conducted on each sample. Each sample was placed in a constant temperature and humidity chamber at 40℃±2℃ and 75%±5% relative humidity. Samples were taken on days 0, 30, 90, and 180, and the changes in the appearance of the samples were observed. The pH value was measured, and the contents of matrine, oxymatrine, astilbene, and ursolic acid were determined again using the above-mentioned high performance liquid chromatography method. The retention rate of the active ingredients at each time point relative to day 0 was calculated. A retention rate of not less than 90% was considered acceptable. At the same time, it was recorded whether precipitation, layering, or color change occurred in each sample.

[0082] Experiment 2: Colloidal network formation ability and skin retention time after dilution were tested. Referring to the descriptions of rheological properties in General Chapter 0631 (pH determination) and General Chapter 9001 (Stability Study of Preparations) of the 2020 edition of the Chinese Pharmacopoeia, the colloidal network formation ability of samples from Examples 1-3 and Comparative Examples 1-6 was evaluated. The concentrated solutions of each sample were diluted 15 times with warm water at 42.5℃ and allowed to stand for 7.5 min. The storage modulus G' and loss modulus G" of the diluted solution were measured using a rotational rheometer at 25℃. The frequency scanning range was 0.1-10 Hz, and the strain amplitude was 1%. A G' value greater than the G" value and a G' value not less than 0.5 Pa were considered as an effective formation of a colloidal network structure. Skin dwell time was measured using an in vitro simulation method. Fresh detached pigskin was cut into 3cm×3cm cubes and fixed on a platform at a 45° angle. 200μL of each sample diluent was evenly spread on the pigskin surface using a micropipette. Methylene blue was added to the diluent to a concentration of 0.05mg / mL. A stopwatch was started, and the pigskin surface was continuously rinsed with 42.5℃ warm water at a flow rate of 0.5mL / min. The endpoint was reached when the blue color on the pigskin surface completely disappeared as observed by the naked eye. The time from the start of rinsing to the complete disappearance of the color was recorded as the skin dwell time. Each group of samples was measured in parallel 6 times, and the average value was taken.

[0083] Experiment 3: Evaluation of antipruritic efficacy and skin irritation safety. Referring to the eczema-related evaluation standards in the "Guiding Principles for Clinical Research of New Traditional Chinese Medicine" and the skin irritation test methods in the 2015 edition of the "Cosmetic Safety Technical Specifications", the antipruritic effect and skin irritation of the samples of Examples 1-3 and Comparative Examples 1-6 were tested respectively. The antipruritic effect was evaluated using a histamine-induced pruritus animal model. SPF-grade male SD rats, weighing 180-220g, were randomly divided into groups of 8. 24 hours before the experiment, the rats' backs were shaved to create a 3cm×3cm bare area. During the experiment, 100μL of 0.1% histamine phosphate solution was injected intradermally into the center of the bare area to induce pruritus. 5 minutes later, the concentrated solution of each sample was diluted 15 times with 42.5℃ warm water, and 2mL was evenly applied to the pruritus area. The scratching behavior of the rats was recorded with a high-definition camera within 30 minutes after the application. The scratching latency and the total number of scratches were counted. The scratching latency was defined as the time from the completion of the application to the first time the rat scratched the pruritus area on its back with its hind limbs. The total number of scratches was the total number of times the rat scratched the pruritus area continuously or intermittently with its hind limbs within 30 minutes. Skin irritation was assessed using a rabbit skin irritation test. Healthy adult New Zealand white rabbits, weighing 2.0-2.5 kg, were used in groups of four. 24 hours prior to the experiment, symmetrical hair was removed from both sides of the rabbit's back to create a 4cm × 4cm bare area, with the left side representing intact skin and the right side representing damaged skin. 0.5 mL of the concentrated sample solution was applied to a 2.5cm × 2.5cm gauze dressing and placed on the bare area, then fixed in place. The dressing was removed after 4 hours. Local erythema and edema were observed and scored at 1 hour, 24 hours, 48 ​​hours, and 72 hours after dressing removal. The irritation index was calculated cumulatively according to the irritation response scoring standard, and the intensity of irritation was determined based on the irritation index.

[0084] Table 1: Initial content of active ingredients and pH value of each example and comparative example

[0085] Note: Content determination was performed according to the high performance liquid chromatography method in General Chapter 0512 of the 2020 edition of the Chinese Pharmacopoeia, Part IV. Comparative Example 6 is a commercially available compound Phellodendron amurense liquid ointment, which does not contain Smilax glabra, therefore astilbin and ursolic acid were not detected and are indicated by "—"; its matrine and oxymatrine contents were determined under the same chromatographic conditions. pH value determination was performed according to General Chapter 0631 of the 2020 edition of the Chinese Pharmacopoeia, Part IV.

[0086] Table 2: Results of accelerated stability tests at 180 days for each embodiment and comparative example

[0087] Note: The accelerated stability test conditions were a temperature of 40℃±2℃ and a relative humidity of 75%±5%. The content retention rate was the percentage of the value measured on day 180 to that measured on day 0. The results of the appearance observations are as follows: Example 1 was a clear brownish-yellow liquid with no precipitation or stratification; Example 2 was a clear brownish-yellow liquid with no precipitation or stratification; Example 3 was a clear brownish-yellow liquid with no precipitation or stratification; Comparative Example 1 was a dark brown liquid with a small amount of flocculent precipitate and slight stratification; Comparative Example 2 was a brownish-yellow liquid with trace precipitation; Comparative Example 3 was a dark brown liquid with obvious precipitation and stratification; Comparative Example 4 was a brownish-yellow liquid with a small amount of precipitation; Comparative Example 5 was a brownish-yellow liquid with a small amount of precipitation and slight stratification; Comparative Example 6 was a brownish-yellow liquid with precipitation appearing on day 90. Examples 1-3 did not show precipitation or stratification at any time point within the 180-day accelerated test, and the pH fluctuation range was within ±0.15; Comparative Example 3 showed obvious precipitation on day 60, while Comparative Examples 1 and 5 began to show precipitation on day 120.

[0088] Table 3: Data on the ability of diluted colloidal networks to form skin retention time

[0089] Note: The pH value of the diluted solution was measured after the concentrate was diluted 15 times with warm water at 42.5℃ and allowed to stand for 7.5 minutes. The criteria for determining the formation of colloidal network were G' > G" and G' ≥ 0.5 Pa. Although the G' values ​​of Comparative Examples 4 and 5 reached the threshold of 0.5 Pa and were marked "Yes*", their G' values ​​were significantly lower than those of Example 1, indicating that the formed colloidal network structure was relatively loose, and the sustained-release effect and residence time were significantly worse than those of Example 1. Skin residence time is expressed as mean ± standard deviation, n=6. Comparative Example 6 was a commercially available compound Phellodendron amurense liquid ointment, which was directly measured after dilution according to the instructions. It does not contain Prunus mume polysaccharide and cannot form a colloidal network structure. Its residence time is only the physical residual time of the drug solution on the pig skin surface, rather than a sustained-release residence based on a colloidal network.

[0090] Table 4: Data on antipruritic efficacy and skin irritation safety evaluation

[0091] Note: Scratching latency and total number of scratches are expressed as mean ± standard deviation, n=8. A longer scratching latency indicates a faster onset of itch relief, and fewer scratches indicate a longer-lasting itch relief effect. Irritation intensity rating results: Example 1 was non-irritating, Example 2 was non-irritating, Example 3 was non-irritating, Comparative Example 1 was slightly irritating, Comparative Example 2 was non-irritating, Comparative Example 3 was moderately irritating, Comparative Example 4 was non-irritating, Comparative Example 5 was non-irritating, and Comparative Example 6 was slightly irritating. Irritation index < 0.5 was non-irritating, 0.5 ≤ irritation index < 2.0 was slightly irritating, and 2.0 ≤ irritation index < 5.0 was moderately irritating.

[0092] Based on Examples 1-3 and Comparative Example 1, and in conjunction with Tables 1-4, it can be seen that the conventional decoction process cannot achieve differentiated extraction of active ingredients from different medicinal materials, resulting in a significant reduction in the dissolution rate of the core active ingredients. At the same time, it cannot construct a closed-loop utilization system for resources within the formula, cannot form a colloidal network structure with sustained-release effect, has poor long-term stability of the preparation, short duration of efficacy, and relatively high skin irritation.

[0093] Based on Examples 1-3 and Comparative Example 2, and in conjunction with Tables 1-4, it can be seen that using purified water instead of the acidic extract of Prunus mume for extraction significantly reduces the dissolution rate and chemical stability of Sophora flavescens alkaloids and Smilax glabra flavonoids. At the same time, it disrupts the gradient utilization logic of the acid solution in the formula, and cannot provide a natural acidic medium for the subsequent enzymatic hydrolysis process, ultimately resulting in a significant decrease in the efficacy and stability of the preparation.

[0094] Based on Examples 1-3 and Comparative Example 3, and in conjunction with Tables 1-4, it can be seen that, although omitting the enzymatic hydrolysis and polysaccharide extraction step of the dried plum residue does not significantly affect the initial content of the active ingredients, it completely loses the material basis for the construction of the colloidal network, making it impossible to achieve sustained release and skin retention of the active ingredients. At the same time, it loses the physical encapsulation and protection effect of polysaccharides on the active ingredients, resulting in a significant decrease in the long-term stability of the formulation and a significant increase in skin irritation.

[0095] As can be seen from Examples 1-3 and Comparative Example 4, and Tables 1-4, adding the plum polysaccharide extract quickly at once will lead to excessively high local concentration of polysaccharides and agglomeration, making it impossible to form a uniformly dispersed non-covalent complex. The resulting colloidal network structure is loose, significantly reducing the sustained-release effect and skin retention capacity, and also affecting the long-term stability of the formulation.

[0096] Based on Examples 1-3 and Comparative Example 5, and in conjunction with Tables 1-4, it can be seen that by omitting the low-temperature static curing process, the initially formed non-covalent complex cannot be regularly arranged through molecular thermal motion, making it difficult to form a structurally stable weakly cross-linked colloidal network precursor. This results in insufficient strength of the colloidal network formed after in-situ activation following dilution, shortening the duration of drug efficacy, and making the formulation more prone to precipitation and stratification after long-term storage.

[0097] As can be seen from Examples 1-3 and Comparative Example 6, and Tables 1-4, commercially available conventional eczema topical washes generally have problems such as complex ingredients, low content of active ingredients, and lack of sustained-release drug delivery systems. Their skin residence time is short, the duration of efficacy is limited, and some preparations have certain skin irritation. The extremely simple formula and closed-loop process system of this application show significant advantages in terms of efficacy and safety.

[0098] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A topical wash for eczema, characterized in that: It is made solely from the following raw materials in parts by weight: 18-22 parts Sophora flavescens, 16-26 parts Prunus mume, and 15-25 parts Smilax glabra.

2. The external wash formula for eczema according to claim 1, characterized in that: The raw materials are in the following proportions by weight: 20 parts Sophora flavescens, 20 parts Prunus mume, and 20 parts Smilax glabra.

3. A method for preparing an external wash for eczema, characterized in that, A topical wash for eczema as described in any one of claims 1 or 2 includes the following steps: S1. Low-temperature segmented extraction: Take the prescribed amount of dried plum, crush it, add purified water, first extract it at low temperature, then heat it to a gentle boil and boil it, and filter it to obtain the acidic extract of dried plum and the dried plum residue. S2, Directed enzymatic hydrolysis of medicinal residue: Take part of the acidic extract of dried plum obtained from S1 and add it to the dried plum residue. After adjusting the pH, pretreat at low temperature, then add compound enzyme for enzymatic hydrolysis. After the enzymatic hydrolysis is completed, inactivate the enzyme and filter to obtain dried plum polysaccharide extract. S3, Acidic Relay Extraction: Take the prescribed amount of Sophora flavescens and Smilax glabra, add the remaining acidic extract of Prunus mume obtained in S1, first keep warm for extraction, then heat to a gentle boil and decoct, filter to obtain the acidic extract of Sophora flavescens and Smilax glabra. S4. Controlled-rate merging and construction: Cool the extract obtained in S3, and slowly add the plum polysaccharide extract obtained in S2 while stirring. After the addition is complete, continue stirring to obtain the merging liquid. S5. Nitrogen-protected concentration: Transfer the combined liquid obtained in S4 into a concentration tank, introduce nitrogen and maintain positive pressure, and avoid light throughout the process. First, perform high-temperature rapid concentration to 40%-50% of the original volume, and then perform low-temperature slow concentration to 1.0-1.5g of total raw drug per milliliter of liquid to obtain the concentrated liquid. S6. Low-temperature curing and shaping: The concentrated solution obtained in S5 is left to stand and cure, so that the non-covalent complexes formed in the solution are arranged in a regularized manner through molecular thermal motion, forming a weakly cross-linked colloidal network precursor. Then, it is filled and sterilized to obtain the finished product.

4. The method for preparing an external wash for eczema according to claim 3, characterized in that: In step S1, the amount of purified water added is 6-10 times the weight of the dried plum, the temperature of the low-temperature extraction is 50-60℃ and the time is 30-45 min, the time of the gentle boiling decoction is 1-1.5 h, the pH value of the obtained acidic extract of dried plum is 2.8-4.0, and it is refrigerated at 2-8℃ for later use.

5. The method for preparing an external wash for eczema according to claim 3, characterized in that: In step S2, the pH is adjusted to 3.5-4.0, the compound enzyme is composed of cellulase and pectinase in a mass ratio of 1:0.5-1:1.5, and the amount added is 0.2%-0.5% of the weight of the dried plum residue. The initial pH of the enzymatic hydrolysis is 4.5-5.5, the temperature is 45-55℃, and the enzyme inactivation conditions are 85-95℃ for 10-20 minutes.

6. The method for preparing a topical wash for eczema according to claim 3, characterized in that: In step S3, the temperature for heat preservation extraction is 60-70℃ and the time is 30-40 min. The time for gentle boiling decoction is 1-1.5 h. The pH value of the acidic extract of Sophora flavescens and Smilax glabra obtained by filtration is 3.2-3.

6. The filter residue is then extracted again with acidic solution or purified water 1-2 times, and the filtrates are combined.

7. The method for preparing an external wash for eczema according to claim 3, characterized in that: In step S4, the temperature is lowered to 40-45℃, the stirring speed is 100-150 r / min, the slow addition time is controlled at 15-20 min, and the stirring time is 10-15 min.

8. The method for preparing a topical wash for eczema according to claim 3, characterized in that: In step S5, the nitrogen positive pressure is 0.02-0.05 MPa, the high-temperature rapid concentration temperature is 70-80℃ and the vacuum degree is -0.08 to -0.09 MPa, the low-temperature slow concentration temperature is 55-65℃ and the vacuum degree is -0.07 to -0.08 MPa, and after concentration, potassium sorbate or sodium benzoate is added as a preservative at a concentration of 0.05%-0.2% of the total volume of the concentrate.

9. The method for preparing an external wash for eczema according to claim 3, characterized in that: In step S6, the temperature for static curing is 35-45℃ and the time is 12-24h, and the sterilization method is 100-105℃ flowing steam sterilization for 30-34min.

10. A method of using a topical wash for eczema, characterized in that, Take the concentrated solution prepared by the eczema external wash formula according to any one of claims 1 or 2, dilute it 10-20 times with warm water at 40-45℃, let it stand for 5-10 minutes to activate it in situ, so that the colloidal network precursor spontaneously absorbs water and swells and is evenly dispersed into a slow-release colloidal network, and then soak or apply it to the affected area 1-2 times a day for 15-20 minutes each time.

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