Pharmaceutical composition for treating damp-heat accumulation type allergic contact dermatitis and preparation method and application thereof

Abstract

The invention provides application of a pharmaceutical composition to preparation of an external medicine for treating allergic contact dermatitis, wherein the pharmaceutical composition is prepared from the following raw material medicines in parts by weight: 25-35 parts of purslane, 25-35 parts of fructus cnidii, 15-25 parts of fructus kochiae, 15-25 parts of nidus vespae, 5-15 parts of cortex dictamni, 5-15 parts of pepper, 10-20 parts of rheum officinale and 10-20 parts of senecio scandens. The invention also provides a preparation method of the pharmaceutical composition. The composition has the effects of clearing heat and drying dampness, cooling blood and diminishing swelling, and dispelling wind and arresting itching, is externally washed on an affected part, effective components directly reach the affected part after being absorbed by skin, has the characteristics of direct action, quick response, convenience and simplicity, small toxic and side effects and the like, has the effects of clearing heat and drying dampness, cooling blood and diminishing swelling, and dispelling wind and arresting itching together, and has a remarkable effect on treating the allergic contact dermatitis.

Description

Technical Field

[0001] The invention relates to a pharmaceutical composition for treating damp-heat accumulation type allergic contact dermatitis, and a preparation method and application thereof. Background Art

[0002] Allergic contact dermatitis is a common inflammatory skin disease, usually caused by contact between the skin and specific external substances. Its pathogenesis mainly involves the immune response or direct stimulation induced by skin contact with allergens or irritants, which leads to various skin lesions such as erythema, papules, blisters, erosions, exudation and scabs, accompanied by subjective symptoms such as itching, burning and pain. The etiology of this disease is complex and diverse. Common allergens include plants (such as lacquer trees, poison ivy, etc.), metals (such as nickel, chromium, etc.), cosmetics, detergents and rubber products, while irritants mainly include strong acids, strong alkalis, hot water and soap. Allergic contact dermatitis has a wide range of patients, affecting about 7% of the general population, 13.3% to 24.5% of pediatric patients and 33% to 64% of the elderly population. In addition, there are significant differences in the incidence of this disease among different populations, and the incidence rate in women is generally higher than that in men.

[0003] In traditional Chinese medicine, allergic contact dermatitis belongs to the category of "lacquer sore", "plaster wind" and "toilet ringworm". It is named according to the different pathogenic substances. For example, those caused by contact with raw lacquer are called "lacquer sore", those caused by contact with plasters are called "plaster wind", and those caused by using toilets are called "toilet ringworm". "Surgery Authentic" records: "Lacquer sore: caused by foreign bodies. Lacquer is a pungent, hot, fire-like and toxic substance. The skin and fur of people are not dense, so they are affected by the poison." This shows that insufficient congenital endowment and abnormal skin barrier function are the main reasons for the body's inability to resist foreign toxins and the onset of the disease. In addition, dampness and heat evil accumulate on the skin surface. Long-term illness will consume yin blood, and the skin will lose nourishment, resulting in symptoms such as dryness, roughness, thickening and scaling. Traditional Chinese medicine believes that the etiology and pathogenesis of this disease are the invasion of foreign toxins, wind, dampness and heat evils invading the skin, coupled with the intolerance of the body endowment, disharmony of qi and blood, and skin loss, which work together to cause the disease. Clinically, drugs such as clearing away heat and detoxifying, dispelling wind and dampness, nourishing blood and moistening dryness are often used for treatment, and can be combined with external application of Chinese medicine, acupuncture and other therapies to enhance the efficacy.

[0004] At present, the treatment options for allergic contact dermatitis are diversified. Western medicine clinical treatment mainly uses glucocorticoids, immunomodulators, topical calcineurin inhibitors, antihistamines and moisturizers. Although they can quickly control symptoms, long-term use may cause adverse reactions such as hypercorticism syndrome, central nervous system depression, cardiotoxic reactions and recurrence after drug withdrawal, posing potential risks to patients' physical and mental health. In contrast, traditional Chinese medicine therapy has shown the advantages of definite efficacy, mild adverse reactions, low irritation and low recurrence rate in the treatment of this disease, and has high patient compliance. Relevant studies in recent years have shown that the application of Chinese medicine external treatment in the treatment of allergic contact dermatitis has increased significantly. Evidence-based medical research has confirmed that commonly used prescriptions are mostly combined with heat-clearing, wind-dispelling and dampness-drying and insecticidal drugs. The characteristics of their medicinal properties are mainly bitter and pungent drugs, and the medicinal properties are mostly warm, flat and cold. The meridians are mainly liver, lung and spleen.

[0005] CN202210181804.0, invention name: a pharmaceutical composition for treating damp-heat accumulation type skin pruritus, provides a pharmaceutical composition for treating damp-heat accumulation type skin pruritus, which is prepared from the following raw materials in parts by weight: 25-35 parts of purslane, 25-35 parts of cnidium monnieri, 15-25 parts of kochia scoparia, 15-25 parts of fried honeycomb, 5-15 parts of Dictamni, 5-15 parts of Zanthoxylum bungeanum, 10-20 parts of raw rhubarb, and 10-20 parts of Senecio radix. The composition of the present invention has the effects of clearing away heat and dampness, cooling blood and reducing swelling, and dispelling wind and relieving itching. It is washed externally on the affected area, and the effective ingredients are absorbed by the skin and reach the affected area directly. It has the characteristics of direct action, quick effect, convenience and simplicity, and small toxic and side effects. The whole recipe plays the role of clearing heat and dampness, cooling blood and reducing swelling, and dispelling wind and relieving itching, and is used to treat skin pruritus. The effect is remarkable. This patent is mainly used to treat skin pruritus, including skin-related pruritus, especially inflammatory skin diseases such as atopic dermatitis and psoriasis.

[0006] Allergic contact dermatitis and atopic dermatitis are both common inflammatory skin diseases, but they differ significantly in etiology, pathogenesis, clinical manifestations, and course of disease. The specific differences are as follows:

[0007] 1. Etiology and pathogenesis

[0008] Allergic contact dermatitis:

[0009] It is a delayed hypersensitivity reaction (type IV allergy) mediated by T cells.

[0010] The onset of the disease is related to contact with specific allergens, such as metals (nickel, chromium), fragrances, dyes, etc.

[0011] There is usually an incubation period of 1 to 2 weeks after the first contact with the allergen, and the disease will not occur until the next contact.

[0012] Atopic dermatitis:

[0013] It is a chronic, relapsing, inflammatory skin disease associated with genetic allergies.

[0014] The pathogenesis is complex and involves genetics, immune abnormalities (such as increased serum IgE levels), and impaired skin barrier function.

[0015] Patients often have a family history of allergies, such as asthma, allergic rhinitis, etc.

[0016] 2. Clinical manifestations

[0017] Allergic contact dermatitis:

[0018] The skin lesions are mainly limited to the areas that come into contact with allergens and have clear boundaries.

[0019] The acute phase is manifested by erythema, papules, blisters, and itching, while the chronic phase may present with lichenification.

[0020] The onset of symptoms usually occurs within 24 to 72 hours after exposure to the allergen.

[0021] Atopic dermatitis:

[0022] The skin lesions are polymorphic, including erythema, papules, blisters, lichenification, etc., with unclear boundaries.

[0023] Dry skin and itching are the core symptoms, often accompanied by desquamation, scratches and pigmentation.

[0024] The manifestations are different in different age groups: infancy is mostly acute eczema, while in childhood and adulthood it is mostly subacute or chronic eczema.

[0025] 3. Disease course and susceptible population

[0026] Allergic contact dermatitis:

[0027] The course of the disease is relatively short, and symptoms can be quickly relieved after the allergen is removed.

[0028] Susceptible groups are individuals who are exposed to specific allergens.

[0029] Atopic dermatitis:

[0030] The disease has a long course, is prone to recurrence, and is often a chronic process.

[0031] It is common in people with a family history of allergies, especially in children and adolescents.

[0032] 4. Diagnosis and treatment

[0033] Allergic contact dermatitis:

[0034] Diagnosis is based mainly on medical history, contact history, and patch testing.

[0035] Treatment involves removal of the allergen and use of topical corticosteroids or nonhormonal anti-inflammatory drugs.

[0036] Atopic dermatitis:

[0037] Diagnosis is based on medical history, family history, and clinical manifestations.

[0038] The goal of treatment is to relieve symptoms, repair the skin barrier, and reduce recurrences, and long-term use of topical medications is often required.

[0039] 5. Other features

[0040] Allergic contact dermatitis:

[0041] The lesions are the same shape as the objects they come into contact with, such as a rash of the same shape after wearing metal jewelry.

[0042] Atopic dermatitis:

[0043] It is often accompanied by other allergic diseases, such as asthma and allergic rhinitis.

[0044] Systemic symptoms may occur, such as sleep disturbances and mental health problems

[0045] Although both allergic contact dermatitis and atopic dermatitis manifest as skin inflammation, the former is mainly caused by contact with allergens, with rapid onset and limited to the contact site; the latter is a chronic, recurrent skin disease that is closely related to genetic and immune abnormalities, with more complex symptoms and a longer course of disease.

[0046] At present, there is no report that the prescription involved in patent application number CN202210181804.0 is used to treat allergic contact dermatitis, nor is there any report on process research for allergic contact dermatitis. Summary of the invention

[0047] The present invention provides a new use of the prescription involved in patent application number CN202210181804.0, specifically, for treating allergic contact dermatitis of damp-heat accumulation type. The present invention also provides a method for preparing the pharmaceutical composition.

[0048] The present invention provides the use of a pharmaceutical composition prepared from the following raw materials in a weight ratio in the preparation of an external medicine for treating allergic contact dermatitis:

[0049] 25-35 parts of Portulaca Oleracea, 25-35 parts of Cnidium monnieri, 15-25 parts of Kochia scoparia, 15-25 parts of Nasturtium officinale, 5-15 parts of Dictamni, 5-15 parts of Zanthoxylum bungeanum, 10-20 parts of Rhubarb, and 10-20 parts of Senecio grandiflora.

[0050] Preferably, the weight ratio of the raw material is:

[0051] 30 parts of purslane, 30 parts of cnidium monnieri, 20 parts of kochia scoparia, 20 parts of apis nigra, 10 parts of dittany, 10 parts of zanthoxylum bungeanum, 15 parts of rhubarb, and 15 parts of senecio; the apis nigra is fried apis nigra; and the rhubarb is raw rhubarb.

[0052] Wherein, the medicine is used to treat allergic contact dermatitis of damp-heat accumulation type.

[0053] The present invention also provides a method for preparing a pharmaceutical composition for treating damp-heat accumulation type allergic contact dermatitis, which comprises the following steps:

[0054] a. Weigh the APIs of various weight ratios:

[0055] 25-35 parts of purslane, 25-35 parts of cnidium monnieri, 15-25 parts of kochia scoparia, 15-25 parts of nectarine, 5-15 parts of dittany, 5-15 parts of zanthoxylum bungeanum, 10-20 parts of rhubarb, and 10-20 parts of senecio;

[0056] b. Add vegetable oil to the raw material medicine, soak, steam and filter to obtain the product.

[0057] The vegetable oil is one of olive oil, sesame oil, camellia oil, peanut oil, soybean oil, rapeseed oil, sunflower oil, corn oil and linseed oil, or a mixture of two or more thereof.

[0058] Preferably, the vegetable oil is olive oil.

[0059] Wherein, the mass volume ratio of the raw material drug to the vegetable oil is: 1:2-4.

[0060] Preferably, the mass volume ratio of the bulk drug to the vegetable oil is 1:2.

[0061] Wherein, the soaking time described in step b is 0.5-1.5h; and the steaming time is 0.5-1h.

[0062] Preferably, the soaking time in step b is 1 hour; the steaming time is 1 hour. The pharmaceutical composition of the present invention is formed based on the prescriptions of famous traditional Chinese medicine practitioners, clinical efficacy, data mining, medication rules and other aspects.

[0063] Clinical trials have found that using vegetable oil as a solvent is effective in treating allergic contact dermatitis.

[0064] Compared with the original patent method, the pharmaceutical composition of the present invention has the following improvements: (1) Promote drug absorption: Olive oil contains a high level of oleic acid, and its long-lasting penetration-enhancing effect can selectively increase the permeability of the skin. Compared with aqueous solutions, its active ingredients are more easily absorbed by the skin, thereby improving the efficacy of the drug. (2) Improve drug stability: Olive oil itself has certain antioxidant properties, which can reduce the oxidation and degradation of the active ingredients in traditional Chinese medicine preparations, help maintain the stability of the drug, and extend the shelf life of the preparation. In order to extend the shelf life of the drug, the original patent method used a certain amount of preservatives, which have a certain irritating effect on the skin. (3) Compared with water solvents, olive oil has the effects of moisturizing, repairing the skin barrier, etc., and compared with the original patent method, it has increased the effect of skin care.

[0065] In addition, the present invention selects olive oil as the base oil, which has the following advantages compared with sesame oil and camellia oil: (3) Compared with sesame oil, olive oil has the advantages of less greasiness, mildness and non-irritation, and no special smell; compared with camellia oil, the polyphenol compounds in olive oil have stronger anti-inflammatory effects. For some inflammatory skin diseases, such as eczema and dermatitis, olive oil can relieve inflammatory symptoms and reduce skin itching and redness.

[0066] The composition of the present invention has the effects of clearing away heat and dampness, cooling blood and reducing swelling, dispelling wind and relieving itching. It is applied to the affected area externally, and the effective ingredients are absorbed through the skin and directly reach the affected area. It has the characteristics of direct action, quick effect, convenience and simplicity, and small toxic and side effects. The whole formula has the effects of clearing away heat and dampness, cooling blood and reducing swelling, dispelling wind and relieving itching, and is significantly effective in treating allergic contact dermatitis. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 Pictures of mouse skin lesions;

[0068] Figure 2 Mouse serum IL-4, IL-13, and IL-31 protein levels (*: p<0.05, **: p<0.005, ***: p<0.0005, ****: p<0.0001);

[0069] Figure 3 Histopathological images of mouse skin lesions stained with HE. DETAILED DESCRIPTION

[0070] Example 1. Preparation of the drug of the present invention

[0071] Recipe: 30g purslane, 30g cnidium monnieri, 20g fried beehive, 10g dactylic acid, 10g zanthoxylum bungeanum, 15g rhubarb, 15g eupatorium, 20g kochia scoparia, and 300ml olive oil.

[0072] Preparation method: Put the formula pieces into a bowl with 300ml olive oil, seal with plastic wrap and soak for 1 hour, then steam in a steamer for 1 hour. Then let it stand and cool, filter with gauze, and you are done.

[0073] Example 2, Preparation of the drug of the present invention

[0074] Recipe: 30g purslane, 30g cnidium monnieri, 20g fried beehive, 10g dactylic acid, 10g zanthoxylum bungeanum, 15g rhubarb, 15g semen armeniaca, 20g kochia scoparia, and 300ml sesame oil.

[0075] Preparation method: Put the formula pieces into a bowl with 300ml sesame oil, seal with plastic wrap and soak for 1 hour, then steam in a steamer for 1 hour. Then let it stand and cool, filter with gauze, and you are done.

[0076] Example 3, Preparation of the drug of the present invention

[0077] Recipe: 30g purslane, 30g cnidium monnieri, 20g fried beehive, 10g dactylic acid, 10g zanthoxylum bungeanum, 15g rhubarb, 15g senecio, 20g kochia scoparia, 300ml camellia oil.

[0078] Preparation method: Put the formula slices into a bowl with 300ml camellia oil, seal with plastic wrap and soak for 1 hour, then steam in a steamer for 1 hour. Then let it stand and cool, filter with gauze, and you are done.

[0079] Comparative Example 1: prepared according to the method of Example 1 of the disclosed text of patent application No. CN202210181804.0.

[0080] The beneficial effects of the present invention and comparative therapeutic effects are described below through animal experiments.

[0081] Experimental Example 1 Experimental study on the treatment of allergic contact dermatitis with the drug of the present invention

[0082] 1. Materials and Methods

[0083] 1.1 Experimental materials and instruments

[0084] 1.1.1 Experimental animals

[0085] During the experiment, male SPF-grade KM mice were selected as research subjects, which were sourced from Chengdu Dashuo Company.

[0086] 1.1.2 Main reagents and instruments

[0087] Reagents: 2,4-dinitrochlorobenzene, Hefei Bomei Biotechnology Co., Ltd.; acetone, Hefei Bomei Biotechnology Co., Ltd., 500 / bottle; Veet Pure Hair Removal Cream; Yibao Pure Water, Hefei Bomei Biotechnology Co., Ltd., net content 350ml / bottle. Mouse TNF-α ELISA kit, Chengdu Changlian Chemical Reagent Co., Ltd., specification: 96T; mouse IL-1β ELISA kit, Chengdu Changlian Chemical Reagent Co., Ltd., specification: 96T; mouse IL-6 ELISA kit, Chengdu Changlian Chemical Reagent Co., Ltd., specification: 96T.

[0088] 2. Experiment

[0089] 2.1 Establishment of mouse ACD model

[0090] During the experimental study, all 21 mice were fed in a specific environment according to the requirements. They were fed for 3 days to adapt to the environment, and then divided into blank group, model group, positive control group, olive oil group, sesame oil group, camellia oil group, solution group (prepared in comparative example 1) based on different treatment methods. The number of each group was equal for comparative analysis. Before the experiment, all experimental subjects were depilated in the middle of the back, and the depilation area was about 2×2cm; on the first day of the experiment (sensitization period), 50μL of 5% DNCB solution was measured with a pipette and applied to the depilated area on the back of the mouse for sensitization; on the second day of the experiment, the operation of the first day was repeated once. On the sixth day of the experiment (induction period), 5μL of 1% DNCB solution was measured with a pipette and applied to the outer side of the right ear of the mouse for stimulation; thereafter, stimulation was performed every 3 days, for a total of 4 times.

[0091] 2.2 Method of administration

[0092] Drug administration started from the sensitization period, and each group was stimulated with 1% DNFB acetone solution for 60 minutes before administration, with an administration area of ​​2×2cm, once a day, until the end of stimulation. The blank group and the model group were coated with distilled water inside and outside the right ear with a pipette, the positive control group was coated with hydrocortisone cream 30mg / mouse / time, and the rest were coated with the corresponding vegetable oil drugs, and the corresponding doses were controlled at 30μl / mouse / time. The mice in the solution group were bathed in solution, and the amount of water was appropriate to completely immerse the itchy area, and the bathing was 15-20min.

[0093] 2.3 Observation indicators and methods

[0094] 2.3.1 Observation of skin lesions

[0095] 24 hours after each application of DNFB, pictures of the mouse skin were taken to record skin lesions such as erythema, edema, ulceration, and scab.

[0096] 2.3.2 Detection of IL-4, IL-13, and IL-31 protein levels in mouse serum

[0097] Five minutes before killing young mice by dislocating the neck, the eyeballs of the mice were removed and blood was collected. After being stored at room temperature for 1 hour, the blood was centrifuged and centrifuged at 3000 rpm for fifteen minutes. The serum was then taken out and tested by enzyme-linked immunosorbent assay in strict accordance with the instructions of the kit to determine the protein content of serum IL-4, IL-13, and IL-31.

[0098] 2.3.3 Histopathological observation of mouse skin lesions by HE staining

[0099] The back lesional skin of mice in the model group, blank group and olive oil group were selected for HE staining, and the stained sections were observed under an optical microscope to observe pathological changes such as the thickness of the epidermis, degree of keratinization, and inflammatory cell infiltration.

[0100] 2.4 Experimental Results

[0101] 2.4.1 Observation results of skin lesions ( Figure 1 )

[0102] The mice in the blank group had no skin lesions, while the mice in the model group showed skin lesions such as erythema, edema, ulceration, and scabs. The severity of the lesions worsened with the extension of modeling time. The skin lesions in the positive control group and the olive oil group were significantly alleviated compared with those in the model group. The skin lesions in the sesame oil group were obvious with scratches. The skin lesions in the camellia oil and solution groups showed a trend of alleviation compared with those in the model group.

[0103] 2.4.2 IL-4, IL-13, and IL-31 protein levels in mouse serum

[0104] The results are shown in the following table: Figure 2 :

[0105] Table 1 IL-4 protein content in mouse serum

[0106]

[0107] Table 2 IL-13 protein content in mouse serum

[0108]

[0109] Table 3 IL-31 protein content in mouse serum

[0110]

[0111] p-value: p-value compared with the blank group, p-value: p-value compared with the model group

[0112] The serum IL-4, IL-13, and IL-31 protein levels of mice in the model group were significantly higher than those in the positive control group and the olive oil group; the serum IL-13 and IL-31 protein levels of mice in the blank group, the positive control group, and the olive oil group were low and had no significant difference; there was no significant difference in the serum IL-4 protein content between the positive control group and the olive oil group; the serum IL-4, IL-13, and IL-31 protein levels of mice in the sesame oil group, the camellia oil group, and the solution group showed a downward trend compared with the model group, but there was no statistical difference.

[0113] 2.4.3 Pathological observation of mouse skin lesions by HE staining ( Figure 3 )

[0114] HE staining showed that the epidermis of the model mice had obvious hyperplasia, hyperkeratosis and parakeratosis, thickening of the stratum acantholyticum, and the epidermal thickness was significantly higher than that of the blank group. Compared with the model group, the epidermal hyperplasia and cell edema of the mice in the olive oil group were significantly reduced, and the epidermal thickness was significantly lower than that of the model group.

[0115] There are literature reports that olive oil induces contact dermatitis (http: / / derm.dxy.cn / article / 510494,

[0116] https: / / www.sohu.com / a / 129959782_464459), the present invention uses olive oil as the extraction solvent, which can exert the best activity in treating allergic contact dermatitis, and is safe and effective to use. Test Example 2 Clinical case of the drug of the present invention treating allergic contact dermatitis

[0117] The patient, male, 53 years old, had red wheals on his upper limbs for 20 days. 20 days ago, the patient developed red wheals the size of a coin at the site of application after applying an external plaster. He felt itchy and had local skin edema. Red wheals were visible, some of which merged into pieces. The lesions were slightly higher than the skin surface. Both upper limbs were swollen. Obvious strip-shaped scratches and blood scabs were visible at the lesions. The skin temperature was high, and he felt severe itching, which affected his sleep at night. The total area of ​​lesions was about 200cm 2 , erosion area is about 70cm 2 . No other discomfort. Diagnosed as "allergic contact dermatitis" and "plaster wind". The drug of the present invention was applied to the skin lesions on the upper limbs twice a day for 2 consecutive weeks. The patient's itching was gradually alleviated, sleep improved at night, and the strip scratches on the limbs decreased. After 2 weeks of treatment, compared with before treatment, the FIIQ scale score decreased by 6.3 points, and the itching VAS score decreased by 4.7 points. The patient was satisfied with the treatment effect.

[0118] The patient, a 65-year-old female, had widespread facial erythema and papules with itching for 1 month. One month ago, the patient developed erythema and papules on her face after applying a facial mask, accompanied by severe itching, especially in the middle of the face, cheeks on both sides, and chin. The patient had widespread facial erythema and papules, mild swelling, obvious burning and tightness, obvious itching, no pain or other discomfort, and the total area of ​​lesions was about 200cm 2 The drug of the present invention was applied to the face twice a day for 2 consecutive weeks. The area of ​​facial lesions of the patient gradually decreased, the skin gradually returned to normal skin color, and the pruritus symptoms were relieved. After 2 weeks of treatment, the FIIQ scale score decreased by 5.5 points and the pruritus VAS score decreased by 4.5 points compared with before treatment. The patient was satisfied with the treatment effect.

Claims

1. Use of a pharmaceutical composition prepared from the following raw materials in a weight ratio in the preparation of an external medicine for treating allergic contact dermatitis: 25-35 parts of Portulaca Oleracea, 25-35 parts of Cnidium monnieri, 15-25 parts of Kochia scoparia, 15-25 parts of Nasturtium officinale, 5-15 parts of Dictamni, 5-15 parts of Zanthoxylum bungeanum, 10-20 parts of Rhubarb, and 10-20 parts of Senecio grandiflora.

2. The use according to claim 1, characterized in that: The weight ratio of the raw material is: 30 parts of purslane, 30 parts of cnidium monnieri, 20 parts of kochia scoparia, 20 parts of apis nigra, 10 parts of dittany, 10 parts of zanthoxylum bungeanum, 15 parts of rhubarb, and 15 parts of senecio; the apis nigra is fried apis nigra; and the rhubarb is raw rhubarb.

3. The use according to claim 1 or 2, characterized in that: The medicine is used for treating allergic contact dermatitis of damp-heat accumulation type.

4. A method for preparing a pharmaceutical composition for treating allergic contact dermatitis of damp-heat accumulation type, characterized in that: It includes the following steps: a. Weigh the APIs of various weight ratios: 25-35 parts of purslane, 25-35 parts of cnidium monnieri, 15-25 parts of kochia scoparia, 15-25 parts of nectarine, 5-15 parts of dittany, 5-15 parts of zanthoxylum bungeanum, 10-20 parts of rhubarb, and 10-20 parts of senecio; b. Add vegetable oil to the raw material medicine, soak, steam and filter to obtain the product.

5. The method for preparing the pharmaceutical composition for treating allergic contact dermatitis of damp-heat accumulation type according to claim 4, characterized in that: The vegetable oil is one of olive oil, sesame oil, camellia oil, peanut oil, soybean oil, rapeseed oil, sunflower seed oil, corn oil and linseed oil, or a mixture of two or more thereof.

6. The method for preparing the pharmaceutical composition for treating skin pruritus of damp-heat accumulation type according to claim 5, characterized in that: The vegetable oil is olive oil.

7. A method for preparing a pharmaceutical composition for treating allergic contact dermatitis of damp-heat accumulation type according to any one of claims 4 to 6, characterized in that: The mass volume ratio of the raw material drug to the vegetable oil is 1:2-4.

8. The method for preparing the pharmaceutical composition for treating allergic contact dermatitis of damp-heat accumulation type according to claim 7, characterized in that: The mass volume ratio of the raw material drug to the vegetable oil is 1:

2.

9. The method for preparing the pharmaceutical composition for treating allergic contact dermatitis of damp-heat accumulation type according to claim 4, characterized in that: The soaking time in step b is 0.5-1.5h; the steaming time is 0.5-1h.

10. The method for preparing the pharmaceutical composition for treating allergic contact dermatitis of damp-heat accumulation type according to claim 9, characterized in that: The soaking time described in step b is 1 hour; the steaming time is 1 hour.

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