Traditional Chinese medicine microemulsion gel for treating acne and preparation method thereof

Abstract

This invention belongs to the field of traditional Chinese medicine preparation technology, and relates to a traditional Chinese medicine microemulsion gel for treating acne and its preparation method. The traditional Chinese medicine microemulsion gel is made from raw materials and excipients. The raw materials include 65% ethanol extracts of six traditional Chinese medicines—Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii—mixed in a mass ratio of 3:3:3:6:2:3, and lavender essential oil, patchouli essential oil, and peppermint essential oil mixed in a mass ratio of 9:4:3. The excipients include baobab oil, polyoxyethylene (40) hydrogenated castor oil, Span 80, 1,3-propanediol, carbomer U20, preservatives, triethanolamine, and purified water. This invention is the first to combine extracts from traditional Chinese medicine formulas with essential oils in a microemulsion gel system, constructing a two-component functional system of "extract + essential oil". This microemulsion gel exerts its therapeutic effect by upregulating MFGE8 protein expression, inhibiting the release of pro-inflammatory factors TNF-α, IL-6, and IL-1β, and reducing acne inflammation through a complete pathway, achieving a multi-target synergistic anti-acne effect. Animal experiments show that the anti-acne efficacy of this microemulsion gel is comparable to that of adapalene gel, without skin or eye irritation.

Description

Technical Field

[0001] This invention belongs to the field of traditional Chinese medicine preparation technology, specifically relating to a traditional Chinese medicine microemulsion gel for treating acne and its preparation method. More specifically, this invention relates to an O / W type microemulsion gel formulation containing extracts of traditional Chinese medicine compound and essential oils of traditional Chinese medicine, and the application of this microemulsion gel in the preparation of topical medications for treating acne. Background Technology

[0002] Acne is a chronic inflammatory skin disease affecting the pilosebaceous unit (Phaseolus). Clinically, it manifests as various types of skin lesions, including comedones, papules, pustules, nodules, and cysts, and commonly occurs on the face, chest, and back—areas with high sebum secretion. Epidemiological surveys show that the global prevalence of acne ranges from 9.4% to 93.3%, with an average prevalence as high as 46.8%, especially among adolescents where the incidence exceeds 85%. This disease not only affects the appearance of the skin but also easily triggers problems such as appearance anxiety, low self-esteem, and social avoidance, seriously damaging physical and mental health, making clinical treatment urgently needed. The currently accepted pathogenesis of acne involves multiple steps, including abnormally elevated androgen levels leading to excessive sebum secretion, abnormal keratinization of the pilosebaceous duct leading to follicular blockage, massive colonization and proliferation of Propionibacterium acnes under anaerobic conditions, and the resulting amplified local inflammatory response and immune dysregulation. Among these, excessive proliferation of Propionibacterium acnes is the core trigger for initiating the inflammatory cascade. Based on the above pathological mechanisms, antibacterial, anti-inflammatory, regulation of follicular keratinization, and improvement of the skin microenvironment have become the core strategies for the clinical treatment of acne.

[0003] Currently, the mainstream topical treatments in clinical practice are mainly retinoids and antibiotics. Retinoids (represented by adapalene gel) exert their therapeutic effects by regulating the differentiation of follicular keratinocytes and improving ductal keratinization. However, their clinical safety is poor. Pharmacological and clinical studies have confirmed that they easily cause irritating adverse reactions such as local dryness, erythema, desquamation, burning, and stinging. The incidence of skin irritation exceeds 60% in clinical practice, especially in the early stages of treatment, leading to poor patient tolerance and low medication adherence. Furthermore, these drugs have a single mechanism of action, regulating keratinocyte differentiation only through the retinoic acid receptor, and cannot effectively intervene in the inflammatory microenvironment or block the inflammatory cascade, thus having limited efficacy for moderate to severe inflammatory acne. Topical antibiotics (represented by clindamycin) can directly inhibit Propionibacterium acnes, showing significant short-term efficacy. However, long-term use has led to increasingly serious problems of cross-resistance and the widespread transmission of multidrug-resistant strains, becoming a major challenge in acne treatment worldwide. Clinical practice has gradually restricted their long-term monotherapy.

[0004] Traditional Chinese medicine topical preparations have become an important direction for the research and development of acne treatment preparations due to their potential advantages such as multiple components, multiple targets, mild and low irritation, and low likelihood of developing drug resistance. Regarding traditional Chinese medicine (TCM) acne-removing preparations, Chinese patent CN104523473A discloses an anti-acne microemulsion system containing patchouli extract and small molecule peptides. However, this technology has a single active component, does not combine with TCM essential oils for synergistic formulation, and lacks systemic in vivo pharmacodynamic data such as rabbit ear acne models, histopathological detection, and quantitative analysis of inflammatory factors. Chinese patent CN113425670A discloses an acne-removing microemulsion gel with curcumin, berberine, and resveratrol as functional components. However, it only physically mixes known single active monomers, does not follow the TCM compound formulation theory, and does not introduce essential oil components. The scientific compatibility of the components is insufficient, and it also lacks in vivo efficacy verification in animal models. Chinese patent CN121015748A discloses a TCM compound acne treatment cold compress mask, but this preparation is a non-residual topical product and cannot achieve long-term drug delivery. It also lacks standardized animal model efficacy evaluation and mechanism exploration. In terms of academic research, existing literature has reported that Dragon's Blood Gel can improve the skin lesion status of rabbit ear acne model by regulating serum TNF-α, IL-6 inflammatory factors and tissue MFGE8 protein expression. However, this study only detected macroscopic changes in a few indicators and did not clarify the intrinsic relationship between the MFGE8 signaling pathway and the clearance of inflammatory cells and inflammation resolution. It also did not conduct a systematic efficacy comparison and non-inferiority evaluation with first-line clinical drugs such as adapalene. The depth of mechanism and clinical reference value are both limited.

[0005] In summary, existing TCM acne treatments and research generally suffer from the following shortcomings: First, the formulation system is incomplete, failing to establish a stratified synergistic combination of "TCM compound extracts + TCM essential oils," making it difficult to fully leverage the multi-component, multi-target comprehensive regulatory efficacy advantages of TCM. Second, an in vivo efficacy evaluation system is lacking; most techniques lack multi-dimensional efficacy data supported by standardized animal models, including quantitative analysis of skin lesion swelling, HE staining histopathological assessment, and quantitative analysis of inflammatory factors. Third, research on the mechanism of action is superficial, failing to delve into the MFGE8 key molecule-mediated mechanism of inflammatory cell clearance and immune balance regulation, thus failing to fully elucidate the core pharmacological principles of the formulation's antibacterial, anti-inflammatory, and skin lesion repair effects. Fourth, a systematic non-inferiority comparative evaluation with first-line clinical drugs (such as adapalene) is lacking, making it difficult to confirm the clinical translational value of the technology. Summary of the Invention

[0006] To address the numerous shortcomings of existing technologies, the primary objective of this invention is to provide a traditional Chinese medicine microemulsion gel for treating acne, along with its preparation method and application. This formulation is based on the traditional Chinese medicine theory of "clearing heat and detoxifying, cooling blood and dispersing nodules." It involves extracting six traditional Chinese medicines—Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii—with 65% ethanol to prepare a herbal extract. Lavender essential oil, patchouli essential oil, and peppermint essential oil are mixed and compounded with baobab oil as the oil phase matrix. A suitable composite surfactant system is added to prepare an O / W type microemulsion gel. This invention verifies its effectiveness in treating acne through in vivo pharmacodynamic evaluations, including skin lesion improvement, histopathology, and regulation of inflammatory factors and MFGE8 protein expression in a rabbit ear acne model. It demonstrates the complete pathway of action: "upregulating MFGE8 protein expression → inhibiting the release of pro-inflammatory factors TNF-α, IL-6, and IL-1β → reducing acne inflammation." A non-inferiority comparison with adapalene gel was also conducted, providing a safe and highly effective new topical traditional Chinese medicine formulation for acne treatment.

[0007] In view of this, the present invention provides a traditional Chinese medicine microemulsion gel for treating acne. This traditional Chinese medicine microemulsion gel uses 65% ethanol extracts of six traditional Chinese medicines—Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii—as the components of the traditional Chinese medicine compound extract. It uses lavender essential oil, patchouli essential oil, and peppermint essential oil as the components of the traditional Chinese medicine essential oil. Baobab oil is used as the oil phase matrix. Polyoxyethylene (40) hydrogenated castor oil and Span 80 (sorbitan monooleate) are used as surfactants. 1,3-propanediol is used as a co-surfactant. Carbomer U20 is used as the gel matrix. Triethanolamine is used as a pH adjuster. Preservatives and purified water are added to prepare the gel.

[0008] Another objective of this invention is to provide a method for preparing the above-mentioned traditional Chinese medicine microemulsion gel, comprising five steps: preparation of traditional Chinese medicine compound extract, preparation of oil phase containing traditional Chinese medicine essential oil, preparation of mixed surfactant, preparation of O / W type microemulsion, and preparation of microemulsion gel.

[0009] Another object of the present invention is to provide the application of the above-mentioned traditional Chinese medicine microemulsion gel in the preparation of pharmaceutical formulations for treating acne.

[0010] To achieve the above objectives, the present invention adopts the following technical solution.

[0011] A traditional Chinese medicine microemulsion gel for treating acne, comprising the following raw and excipient materials for preparing 100 parts by weight: 1.0-5.0 parts of traditional Chinese medicine compound extract, 0.5-1.0 parts of traditional Chinese medicine essential oil, 2.0-8.0 parts of oil phase matrix, 5.0-20.0 parts of surfactant A, 2.0-10.0 parts of surfactant B, 2.0-10.0 parts of co-surfactant, 0.5-2.0 parts of gel matrix, and 1.5 parts of preservative. Triethanolamine is added to adjust the pH to 5.5-6.5, and water is added to bring the total to 100 parts. It should be noted that "parts" in this application refer to parts by weight, while in specific embodiments, "g" is used as the unit of measurement for material addition, and the proportions of the two are corresponding.

[0012] The traditional Chinese medicine compound extract is obtained by mixing six traditional Chinese medicines, namely Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii, and extracting, concentrating, drying, and pulverizing them with 65% ethanol; the mass ratio of the six traditional Chinese medicines, namely Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii, is 3:3:3:6:2:3.

[0013] Furthermore, the preparation method of the traditional Chinese medicine compound extract is as follows: Weigh six herbs—Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii—in a mass ratio of 3:3:3:6:2:3; add 10 times the amount of 65% ethanol and soak for 1 hour; extract by reflux three times, 2 hours each time, using 10 times the amount of 65% ethanol each time; filter the extract and combine the filtrates; concentrate under reduced pressure to a concentration equivalent to 0.42-0.46 g of raw herbs per ml; refrigerate at 3℃-5℃ for 24 hours. Remove the insoluble precipitate at the bottom, place in an evaporating dish, freeze-dry, pulverize, and seal for storage to obtain the final product.

[0014] The herbal essential oil is made by mixing lavender essential oil, peppermint essential oil and patchouli essential oil, with a mass ratio of 9:4:3.

[0015] Furthermore, the lavender essential oil, peppermint essential oil, and patchouli essential oil are obtained by pre-extracting lavender, peppermint slices, and patchouli slices respectively using ultrasonic pre-extraction and then extracting them by steam distillation.

[0016] The oil phase matrix is ​​baobab oil; the surfactant A is polyoxyethylene (40) hydrogenated castor oil, and the surfactant B is Span 80; the co-surfactant is 1,3-propanediol; the gel matrix is ​​carbomer U20; and the preservative is one or any combination of two or three of p-hydroxyacetophenone, 1,2-hexanediol, and 1,2-pentanediol.

[0017] As a preferred embodiment, the raw and auxiliary materials used to prepare 100 parts of the aforementioned traditional Chinese medicine microemulsion gel, by weight, include: 4.0 parts of traditional Chinese medicine compound extract, 0.64 parts of traditional Chinese medicine essential oil, 3.36 parts of oil phase matrix, 9.6 parts of surfactant A, 3.2 parts of surfactant B, 3.2 parts of co-surfactant, 1.0 part of gel matrix, and 1.5 parts of preservative. Triethanolamine is added to adjust the pH value to 6.0, and water is added to make up to 100 parts.

[0018] A further preferred embodiment is that, by weight, the raw and auxiliary materials used to prepare 100 parts of the aforementioned traditional Chinese medicine microemulsion gel include: 4.0 parts of traditional Chinese medicine compound extract, 0.64 parts of traditional Chinese medicine essential oil, 3.36 parts of baobab oil, 9.6 parts of polyoxyethylene (40) hydrogenated castor oil, 3.2 parts of Span 80, 3.2 parts of 1,3-propanediol, 1.0 part of carbomer U20, 1.5 parts of preservative, and triethanolamine to adjust the pH to 6.0, and water to make up to 100 parts.

[0019] Based on this, a further technical solution is that the traditional Chinese medicine microemulsion gel of the present invention is used to treat acne. The traditional Chinese medicine microemulsion gel is a topical preparation.

[0020] Furthermore, the herbal microemulsion gel exerts its therapeutic effect on acne by upregulating MFGE8 protein expression and inhibiting the release of pro-inflammatory factors.

[0021] Preferably, the pro-inflammatory factors include TNF-α, IL-6, and IL-1β.

[0022] Based on this, a further technical solution is a method for preparing a traditional Chinese medicine microemulsion gel for treating acne, which specifically includes the following steps.

[0023] S01. Preparation of compound extract of traditional Chinese medicine: six Chinese herbs, namely Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorn and Trichosanthes kirilowii, were weighed according to the mass ratio of 3:3:3:6:2:3. They were extracted with 65% ethanol. The extract was freeze-dried to obtain freeze-dried powder of compound extract of traditional Chinese medicine. S02. Preparation of the oil phase containing Chinese herbal essential oils: Take lavender essential oil, peppermint essential oil and patchouli essential oil in a mass ratio of 9:4:3 and mix them evenly to obtain a mixed essential oil; take 0.5-1.0 parts of the mixed essential oil, add 2.0-8.0 parts of baobab oil, mix evenly to obtain the oil phase containing Chinese herbal essential oils; S03. Preparation of mixed surfactant: Take 5.0-20.0 parts of polyoxyethylene (40) hydrogenated castor oil, 2.0-10.0 parts of Span 80, and 2.0-10.0 parts of co-surfactant (1,3-propanediol), mix them evenly to obtain mixed surfactant; Preparation of S04.O / W type microemulsion: Under stirring conditions, take the mixed surfactant obtained in step S03, add the oil phase containing Chinese herbal essential oil obtained in step S02 dropwise to it, mix well, and then add the resulting oil phase mixture dropwise to 20 parts of purified water to form O / W type microemulsion. S05. Preparation of microemulsion gel: Under stirring conditions, add 0.5-2.0 parts of gel matrix (carbomer U20) to the O / W type microemulsion obtained in step S04 in portions, stir thoroughly, and let it swell fully at room temperature for 48 hours. Then add 1.0-5.0 parts of lyophilized powder of traditional Chinese medicine compound extract obtained in step S01, stirring while adding until completely dissolved. Add triethanolamine to adjust the pH to 5.5-6.5, then add 1.5 parts of preservative, and finally add water to 100 parts. Stir evenly to obtain an orange-yellow, semi-transparent, clear, semi-solid microemulsion gel.

[0024] As a preferred embodiment, the preparation method specifically includes: S01. Preparation of compound extract of traditional Chinese medicine: six Chinese herbs, namely Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorn and Trichosanthes kirilowii, were weighed according to the mass ratio of 3:3:3:6:2:3. They were extracted with 65% ethanol. The extract was freeze-dried to obtain freeze-dried powder of compound extract of traditional Chinese medicine. S02. Preparation of the oil phase containing Chinese herbal essential oils: Take lavender essential oil, peppermint essential oil and patchouli essential oil in a mass ratio of 9:4:3 and mix them evenly to obtain a mixed essential oil; take 0.64 parts of the mixed essential oil, add 3.36 parts of baobab oil, mix evenly to obtain the oil phase containing Chinese herbal essential oils; S03. Preparation of mixed surfactant: Take 9.6 parts of polyoxyethylene (40) hydrogenated castor oil, 3.2 parts of Span 80 and 3.2 parts of 1,3-propanediol, mix them evenly to obtain mixed surfactant; Preparation of S04.O / W type microemulsion: Under stirring conditions, take 16 parts of the mixed surfactant obtained in step S03, add 4 parts of the oil phase containing Chinese herbal essential oil obtained in step S02, mix well, and then add the resulting mixture dropwise to 20 parts of purified water to form an O / W type microemulsion. S05. Preparation of microemulsion gel: Under stirring conditions, add 1.0 part of carbomer U20 to the O / W type microemulsion obtained in step S04 in portions, stir thoroughly, and let it swell fully at room temperature for 48 hours. Then add 4.0 parts of lyophilized powder of traditional Chinese medicine compound extract while stirring until completely dissolved. Add triethanolamine to adjust the pH to 6.0, then add 1.5 parts of preservative, and finally add water to 100 parts. Stir evenly to obtain microemulsion gel.

[0025] The particle size of the herbal microemulsion gel described in this invention is 20nm-100nm.

[0026] The preparation method of the traditional Chinese medicine microemulsion gel of the present invention, and the optimized experimental results of the main processes of traditional Chinese medicine extraction and formulation are as follows.

[0027] 1. Comparative test results of the antibacterial effects of Chinese herbal extracts and mixed essential oils obtained by water extraction and alcohol precipitation method and alcohol extraction method.

[0028] (1) Method for preparing traditional Chinese medicine extract by water extraction and alcohol precipitation and its antibacterial effect: Weigh 45g of Coptis chinensis, 45g of Forsythia suspensa, 45g of Paeonia lactiflora, 90g of Taraxacum mongolicum, 30g of Gleditsia sinensis thorns, and 45g of Trichosanthes kirilowii (total 300g), add 8 times the amount of water, soak for 1 hour, decoct for 30 minutes, add 7 times the amount of water for the second and third decoctions respectively, decoct for 30 minutes, combine the decoctions and concentrate at low temperature to 300mL to obtain a concentrated decoction. Add 975ml of 85% ethanol to the concentrated decoction with slow and fast stirring to make the final concentration of ethanol in the decoction 65%, and refrigerate at 4℃ for 48 hours to precipitate impurities. Filter out the supernatant, wash the precipitate 5 times with 65% ethanol, sonicate with 45ml of 65% ethanol for 15 minutes each time, centrifuge, combine the supernatants, and concentrate under reduced pressure to 150mL. The concentrate was placed in a 50℃ water bath for 1 hour, sonicated for 10 minutes, then placed in a water bath for 2 hours and sonicated for 10 minutes. The black insoluble matter was removed, and the concentrate was freeze-dried to obtain a freeze-dried powder of the water-extracted and alcohol-precipitated herbal extract, with a dry powder yield of 20.99%. The freeze-dried powder was prepared into a microemulsion. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the freeze-dried powder microemulsion of the water-extracted and alcohol-precipitated herbal extract against Staphylococcus aureus, Propionibacterium acnes, and Staphylococcus epidermidis were quantitatively determined using the 2-fold dilution method. The MICs of the positive control drug clindamycin hydrochloride gel against Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis were 0.0195, 0.039, and 0.156 mg / ml, respectively, and the MBCs were 1.25, 2.5, and 0.625 mg / ml, respectively. The MICs of the freeze-dried powder microemulsion of the water-extracted and alcohol-precipitated herbal extract against the three bacteria were 93.75, 187.5, and 50 mg / ml, respectively.

[0029] (2) Method for preparing traditional Chinese medicine extract by alcohol extraction and its antibacterial effect: 200g of the prescribed amount of Paeonia lactiflora, Coptis chinensis, Taraxacum mongolicum, Gleditsia sinensis thorns, Forsythia suspensa, and Trichosanthes kirilowii were added to 10 times the amount of 65% ethanol, soaked for 1 hour, and refluxed three times; each time for 2 hours, each time using 10 times the amount of 65% ethanol; the extract was filtered, and the filtrates were combined; concentrated under reduced pressure to 0.42g-0.46g of raw herbs per ml; refrigerated at 3℃-5℃ for 24 hours; the bottom precipitate and insoluble matter were removed, placed in an evaporating dish, freeze-dried, pulverized, and sealed for storage. The dry extract rate was 24.93%. The lyophilized powder obtained by alcohol extraction was made into a microemulsion, and the minimum inhibitory concentration (MIC) of the lyophilized powder microemulsion of the alcohol-extracted traditional Chinese medicine extract against Propionibacterium acnes was quantitatively determined using the 2-fold dilution method: 10mg / ml, and the minimum bactericidal concentration was 20mg / ml.

[0030] Based solely on the comparison of antibacterial activity against Propionibacterium acnes, the traditional Chinese medicine extract prepared by alcohol extraction has a better antibacterial effect than the traditional Chinese medicine extract prepared by water extraction and alcohol precipitation.

[0031] (3) Antibacterial effects of herbal essential oils: The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of patchouli, lavender, peppermint essential oils and the positive control clindamycin phosphate gel against Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis were qualitatively determined using the 2-fold dilution method. The results were as follows: The MICs of the positive control clindamycin phosphate gel against Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis were 0.3125, 1.25, and 0.625 mg / ml, respectively, and the MBCs were 2.5, 10, and 5 mg / ml, respectively. The MICs of patchouli essential oil against the three bacteria were 0.3125, 0.15625, and 0.3125 mg / ml, respectively, and the MBCs were 1.25, 1.25, and 5 mg / ml, respectively. The MICs of lavender essential oil against the three bacteria were 10, 5, and 20 mg / ml, respectively, and the MBC against Propionibacterium acnes was 20 mg / ml. The MICs of peppermint essential oil against the three bacteria were 5, 1.25, and 5 mg / ml, respectively, and the MBCs were 10, 1.25, and 5 mg / ml, respectively. The MBC against Propionibacterium acnes was 10 mg / ml.

[0032] 2. Optimization of formulation forming process.

[0033] Two plant oils with certain effects on acne were selected: baobab oil and rosehip oil, as well as chemical oils such as polyethylene glycol glyceride (Labrafil M1944CS) as the oil phase. Twelve surfactants were selected: Tween-80, Tween-20, Tween-65, Cremophor RH-40 (RH40), Span 20 (Span20), Span 40 (Span40), Span 80 (Span80), Span 85 (Span85), polyoxyethylene (4) lauryl ether (Brij 30), polyoxyethylene (35) castor oil (CremophorEL), octanoic acid caprylic acid glyceride (Labrasol), and octylphenol polyoxyethylene ether (Triton X-100); three co-surfactants: anhydrous ethanol, 1,3-propanediol, and polyethylene glycol 400 (PEG-400) were selected as emulsifiers. Different ratios were selected, and the total mass was fixed at 1g. The mixture was mixed evenly and then emulsified dropwise into 10mL of distilled water at room temperature while stirring. The mixture was then thoroughly mixed and evaluated using the evaluation indicators in Table 1 to assess the compatibility of the oil phase, surfactant, and co-surfactant.

[0034] Table 1 Scoring Indicators for Acne-Clearing Microemulsion Formation Ⅰ 700nm transmittance (T%) 26-30 points: 100%-91%; 21-25 points: 90%-86%; 16-20 points: 85%-80%; 11-15 points: 80%-70%; 5-10 points: 70%-60%; 0 points: below 60%. Ⅱ Appearance and shape 26-30 points: Clear and transparent (or with a milky sheen); 21-25 points: Semi-transparent and milky; 16-20 points: Light white and semi-transparent; 11-15 points: Milky and semi-transparent; 6-10 points: Milky and opaque; 1-5 points: Thick white milk; 0 points: Layered, oil droplets, flocculent matter. Ⅲ <![CDATA[12000r.min -1 Stability after centrifugation for 20 minutes 20 points: No change; 0 points: Layering, oil droplets, flocculent matter Ⅳ Appearance after standing at room temperature, away from light for 24 hours 20 points: Clear, no layering; 11-19 points: Turbid, no layering; 0 points: Layering, oil droplets, flocculent matter. First, the oil phase was fixed as baobab oil, the co-surfactant was 1,3-propanediol, the oil:emulsifier ratio was 2:8, and the surfactant:co-surfactant ratio was 2:1. Twelve surfactants were prepared individually or in pairs to form microemulsions, which were then evaluated and screened. Based on the results, Brij 30, Labrasol, Span20, and Span80 were selected to be further screened with RH40.

[0035] The results showed that the Span80:RH40:1,3-propanediol combination was better. Further screening was conducted using this combination for the oil phase: baobab oil, rosehip oil, polyethylene glycol glycerol oleate, and polyethylene glycol glycerol oleate. The emulsifier was Span80:RH40:1,3-propanediol at a ratio of 1.5:1.5:1. The results again showed that baobab oil was the most effective. Therefore, baobab oil was chosen as the oil phase, and RH40:Span80:1,3-propanediol was used as the ratio for surfactant and co-surfactant selection.

[0036] Considering the comprehensive scores, transmittance trends, and long-term stability of the formulation under different oil-emulsifier ratios, the final ratio of Span80:RH40:1,3-propanediol was determined to be 3:1:1. Finally, with the RH40:Span80:co-emulsifier ratio fixed at 3:1:1, 1,3-propanediol, PEG400, and ethanol were selected as co-emulsifiers for screening. The formulations of 1,3-propanediol and PEG400 were clearer than those of ethanol. 1,3-propanediol was clearer at lower oil:emulsifier ratios, while PEG400 was clearer at higher oil:emulsifier ratios. Considering all factors, 1,3-propanediol was chosen as the co-emulsifier. The final microemulsion oil phase was determined to be baobab oil, and the emulsifier was determined to be RH40:Span80:1,3-propanediol 3:1:1. By measuring the transmittance of the microemulsion at different dilution ratios, an oil:emulsifier ratio of 2:8 was selected.

[0037] Table 2 Preliminary Screening Results of Surfactant Types and Compound Formulations 1 Span20 1,3-Propanediol 2:1 Milk-like translucent milk 35 2 Span40 1,3-Propanediol 2:1 White thick milk 25 3 Brij 30 1,3-Propanediol 2:1 Milk-like translucent milk 35 4 Transcutol HP 1,3-Propanediol 2:1 Light white semi-transparent milk 40 5 Triton X-100 1,3-Propanediol 2:1 Layering 0 6 Tween-65 1,3-Propanediol 2:1 Milk-like milk 30 7 Cremophor EL 1,3-Propanediol 2:1 Milk-like milk 30 8 Cremophor EL, Span85 1,3-Propanediol 1:1:1 Milk-like milk 30 9 Cremophor EL, Span20 1,3-Propanediol 1:1:1 Milk-like milk 30 10 Cremophor EL, Span80 1,3-Propanediol 1:1:1 Milk-like milk 30 11 RH40, Span80 1,3-Propanediol 1:1:1 translucent opalescent solution 85 12 RH40, Span80, Span20 1,3-Propanediol 2:1:1:2 clear opalescent solution 95 13 Span40, RH40 1,3-Propanediol 1:1:1 clear opalescent solution 90 14 RH40, Span20 1,3-Propanediol 1:1:1 clear opalescent solution 90 15 Brij 30, RH40 1,3-Propanediol 1:1:1 clear opalescent solution 95 16 Labrasol, RH40 1,3-Propanediol 1:1:1 clear opalescent solution 93 17 Cremophor EL, RH40 1,3-Propanediol 1:1:1 Milk-like translucent milk 35 18 Triton X-100, RH40 1,3-Propanediol 1:1:1 Milk-like translucent milk 35 19 Span85, RH40 1,3-Propanediol 1:1:1 Milk-like milk 30 20 Tween 65, RH40 1,3-Propanediol 1:1:1 Milk-like translucent milk 35 Table 3. Compatibility of emulsifiers Brij 30, Labrasol, and Span 20 with RH40 1 Brij 30:RH40:1,3-Propanediol 1:1:1 1:9 translucent solution 90 2:8 clear opalescent solution 85 3:7 Milk-like milk 34 4:6 Milk-like milk 32 2 Labrasol:RH40:1,3-Propanediol 1:1:1 1:9 translucent solution 91 2:8 clear opalescent solution 86 3:7 Light white semi-transparent milk 40 4:6 Milk-like milk 33 3 Span20:RH40:1,3-Propanediol 1:1:1 1:9 clear opalescent solution 92 2:8 clear opalescent solution 87 3:7 Light white semi-transparent milk 40 4:6 Milk-like milk 33 4 Brij 30: Span80: RH40: 1,3-Propanediol 1:1:1:1 1:9 Light white semi-transparent milk 40 2:8 Light white semi-transparent milk 48 3:7 clear opalescent solution 87 4:6 translucent opalescent solution 83 5 Span40: Span80: RH40: 1,3-Propanediol 1:1:1:1 1:9 Opalescent solution 80 2:8 Milk-like translucent milk 40 3:7 Milk-like milk 33 4:6 Milk-like milk 32 6 Span80:RH40:1,3-Propanediol 1.5:1.5:1 1:9 clear opalescent solution 95 2:8 clear opalescent solution 94 3:7 clear opalescent solution 90 4:6 translucent opalescent solution 85 7 RH40:Brij 30:1,3-Propanediol 1.5:1.5:1 1:9 translucent opalescent solution 83 2:8 milky lotion 34 3:7 milky lotion 32 Table 4 Screening Table for Span80:RH40:1,3-Propanediol Ratio 1 1.5:1.5:1 1:9 clear solution 94 2:8 clear opalescent solution 88 3:7 clear opalescent solution 87 4:6 A bright, transparent, yellowish solution 76 5:5 milky 35 2 2:1:1 1:9 clear solution 95 2:8 clear opalescent solution 89 3:7 clear opalescent solution 83 4:6 A bright, transparent, yellowish solution 67 5:5 milky 37 3 2:2:1 1:9 clear solution 91 2:8 clear opalescent solution 88 3:7 clear opalescent solution 87 4:6 Opaque and clearly transparent solution 71 5:5 Opacity and translucent solution 48 4 2.4:1.6:1 1:9 clear opalescent solution 88 2:8 clear opalescent solution 88 3:7 opalescence solution 87 4:6 solutions with obvious opalescence 77 5:5 opalescent translucent solution 50 5 1.8:1.2:1 1:9 clear opalescent solution 92 2:8 clear opalescent solution 90 3:7 opalescence solution 87 4:6 solutions with obvious opalescence 75 6 3:1:1 1:9 clear opalescent solution 95 2:8 clear opalescent solution 94 3:7 opalescence solution 85 4:6 solutions with obvious opalescence 73 5:5 opalescent translucent solution 39 7 4:1:1 1:9 clear opalescent solution 98 2:8 clear opalescent solution 87 3:7 opalescence solution 81 4:6 solutions with obvious opalescence 79 5:5 lotion 39 Table 5 Screening table for co-emulsifiers when the ratio of RH40:Span80:co-emulsifier is 3:1:1. 1 ethanol 1:9 clear solution 90 2:8 clear opalescent solution 80 3:7 clear opalescent solution 72 4:6 A bright, transparent, yellowish solution 63 5:5 milky 35 2 PEG400 1:9 clear solution 93 2:8 clear opalescent solution 86 3:7 clear opalescent solution 78 4:6 A bright, transparent, yellowish solution 67 5:5 milky 53 3 1,3-Propanediol 1:9 clear solution 95 2:8 clear opalescent solution 88 3:7 clear opalescent solution 75 4:6 Opaque and clearly transparent solution 64 5:5 Opacity and translucent solution 48 4 1,3-Propanediol:PEG400 (mass ratio 1:1) 1:9 clear opalescent solution 94 2:8 clear opalescent solution 87 3:7 opalescence solution 78 4:6 solutions with obvious opalescence 65 5:5 opalescent translucent solution 50 Table 6. Transmittance of Microemulsions at Different Dilution Factors 1 2.4:1.6:1 1:9 Original solution 75.7 Dilute 2 times 84.0 2:8 Dilute 4 times 91.3 Diluted 8 times 95.9 3:7 Dilute 6 times 75.9 Diluted 7 times 78.5 4:6 Diluted 8 times 63.5 2 3:1:1 1:9 Original solution 79.5 2:8 Original solution 88.3 Dilute 4 times 92.8 3:7 Dilute 6 times 87.3

[0038] Acne due to heat-toxin and blood stasis is a common skin disease among adolescents. Clinically, it is mainly characterized by facial papules, red pustules, and nodules and cysts, often accompanied by local redness, swelling, heat, pain, excessive sebum secretion, red tongue, and yellow tongue coating. The core pathogenesis of this disease is the stagnation of heat-toxin in the blood, which obstructs the flow of qi and blood, accumulates in the skin, and eventually leads to pus formation. The basic treatment principle is to clear heat and detoxify, cool the blood and dissipate nodules, and promote pus drainage.

[0039] This invention's prescription is based on the traditional Chinese medicine theories of clearing heat and detoxifying, cooling blood and dispersing nodules, and combined with the antibacterial, anti-inflammatory, sebum-regulating and penetration-promoting principles of modern aromatherapy. It aims to act directly on facial skin to clear heat toxins (inflammation and infection) in hair follicles, dredge blood stasis (improve redness and swelling and nodules), and regulate sebum secretion.

[0040] The original prescription of the compound herbal extract used in this invention originates from the clinical experience of Gao Ruhong, a renowned traditional Chinese medicine doctor at the Ningxia Hui Autonomous Region Traditional Chinese Medicine Hospital. This prescription is based on the principles of "for those with skin conditions, induce sweating" from the *Huangdi Neijing Suwen* and the surgical treatment philosophy of "valuing elimination and fearing stagnation" from Wang Weide's *Wai Ke Zheng Zhi Quan Sheng Ji* (Complete Collection of Surgical Treatments) from the Qing Dynasty. It is modified from the "Xian Fang Huo Ming Yin" (Life-Saving Decoction for Women) in Xue Ji's *Jiao Zhu Fu Ren Liang Fang* (Annotated Collection of Effective Prescriptions for Women) from the Ming Dynasty. The formula retains the original three herbs: red peony root, soapberry thorn, and trichosanthes root, replacing components such as honeysuckle with coptis root, forsythia fruit, and dandelion. It possesses the effects of clearing heat and detoxifying, reducing swelling and promoting pus drainage, cooling blood and promoting blood circulation. This formula has a well-structured composition and rigorous logic, and long-term clinical application has verified its stable therapeutic effect on acne of the heat-toxin and blood stasis type. The original formula is a clinically proven topical prescription, traditionally used as a decoction for external washing. While it has potential efficacy for local skin lesions such as acne, it suffers from limitations including low transdermal absorption of active ingredients, slow onset of action, inconvenience for patients, and poor patient compliance. To address these issues, this invention optimizes the dosage form while retaining the original topical administration route. It combines extracts from the traditional Chinese medicine compound with essential oils to create a proprietary topical preparation for the symptomatic treatment of acne.

[0041] The formula uses Coptis chinensis and Taraxacum mongolicum as the principal herbs to clear heat and detoxify, and to purge the fire toxins from sores and ulcers. Coptis chinensis is bitter and cold in nature, and enters the heart, spleen, stomach, liver, and gallbladder meridians. It can clear damp-heat and fire toxins from the upper and middle jiao, and is particularly good at clearing excess heat from the heart and stomach meridians, removing accumulated heat toxins from the body. Its drying and detoxifying effects can improve the local inflammatory state of acne. Taraxacum mongolicum is sweet and slightly bitter, and cold in nature, and enters the liver and stomach meridians. Its heat-clearing and detoxifying effects are stable and definite, and it also has the effects of reducing swelling and dissipating nodules, and promoting diuresis and relieving strangury. The two herbs complement each other and make up a large proportion of the formula. The dosage of dandelion is higher than that of Coptis chinensis, mainly clearing the accumulated toxins in the Yangming stomach and Jueyin liver meridians. Its target is concentrated and can act on the core lesions.

[0042] Forsythia and Paeonia lactiflora are used as assistant herbs to work together to cool the blood, promote blood circulation, disperse nodules, and reduce swelling. Forsythia is bitter and slightly cold in nature, entering the heart and small intestine meridians. It is a commonly used herb in surgery for treating sores, clearing heat from the heart and detoxifying sores. It has a good effect on dispersing carbuncles and swellings. Its light and penetrating nature can assist the principal herb in dispersing the stagnant heat on the surface of the skin. Paeonia lactiflora is bitter and slightly cold in nature, entering the liver meridian. It is good at clearing heat, cooling the blood, dispersing blood stasis, and relieving pain. It directly enters the blood and improves the pathological manifestations such as subcutaneous induration and local redness and swelling caused by blood heat stagnation, flesh necrosis, swelling and pain. The combination of these two herbs assists the principal herb in enhancing the effect of clearing heat and detoxifying, and specifically improves the pathogenesis of excess syndromes such as blood stasis and phlegm accumulation. When heat is cleared, the stagnant heat in the blood is relieved and the flow of qi and blood is smooth. When blood stasis is dispersed, the meridians are unblocked and local swelling and pain are relieved.

[0043] Using Gleditsia sinensis thorns and Trichosanthes kirilowii as adjuvant herbs, this formula combines the functions of promoting pus drainage and eliminating toxins, moisturizing dryness and protecting yin, and harmonizing the overall formula. Gleditsia sinensis thorns are pungent and warm in nature, entering the liver and stomach meridians. Their medicinal properties are penetrating and permeable, reducing swelling and eliminating toxins, draining pus and dispersing nodules, guiding the medicine to act on deep lesions in the skin, promoting the discharge of pus and clearing the pathogenesis of pathogens. Trichosanthes kirilowii thorns are bitter and slightly sweet in nature, cold in nature, entering the lung and stomach meridians. They can clear heat and purge fire, reduce swelling and drain pus, assisting Gleditsia sinensis thorns in clearing deep pus. Furthermore, their sweet and cold properties of generating fluids and moisturizing dryness can restrain the bitter, cold, and drying properties of Coptis chinensis and Taraxacum mongolicum, avoiding the problems of long-term use depleting yin fluids and damaging the skin. Simultaneously, they moisten the wound surface, improving dryness, tightness, and cracking of the sores. The two herbs, one warm and one cold, one penetrating and one moisturizing, can work synergistically with the principal and assistant herbs to clear local pathological products, while also harmonizing the overall formula and reducing imbalances. The formula's composition and compatibility are logically sound.

[0044] Gleditsia sinensis thorns also serve as an adjuvant, guiding and directing the other herbs. This formula does not use licorice to harmonize the herbs; instead, Gleditsia sinensis thorns fulfill this adjuvant function. Gleditsia sinensis thorns are pungent, warming, and penetrating, effectively clearing the skin and pores, guiding the entire formula's effects onto the facial skin's meridians and hair follicle lesions, thus enhancing the targeted efficacy of the drugs. The entire formula combines warming and cooling properties, with cooling and clearing as the primary mechanism of action. The warming nature of Gleditsia sinensis thorns balances the cooling properties of the other herbs, preventing the bitter and cold herbs from stagnating qi and blood, and hindering the flow of pathogenic factors. The cooling herbs clear heat and toxins, dissipate blood stasis, and their pungent and warming properties are contained within the clearing and dispersing action, achieving a cooling without stagnation and a clearing without congestion, ultimately achieving the therapeutic effects of clearing heat and toxins, cooling blood and removing blood stasis, and promoting pus drainage and dissipating nodules.

[0045] This formula combines warming and cooling properties, with a focus on cooling, clearing and eliminating, and treating both the symptoms and the root cause. It is specifically designed to treat acne caused by heat toxins and blood stasis (symptoms include red papules and pustules on the face, or nodules and cysts, local redness, swelling, heat and pain, excessive sebum secretion, red tongue or petechiae, and yellow tongue coating), corresponding to moderate to severe inflammatory acne in modern medicine.

[0046] This invention is the first to discover and verify that the obtained traditional Chinese medicine microemulsion gel exerts its therapeutic effect on acne through the following complete pathway: upregulating MFGE8 protein expression → inhibiting the release of pro-inflammatory factors TNF-α, IL-6, and IL-1β → alleviating the inflammatory response of acne. This mechanism is reported for the first time in topical traditional Chinese medicine preparations for treating acne.

[0047] Building upon this foundation, this invention, based on modern natural drug research and transdermal drug delivery theory, further scientifically combines the aforementioned traditional Chinese medicine compound extract with traditional Chinese medicine essential oils, overcoming the limitations of traditional topical Chinese medicine preparations. The traditional Chinese medicine compound extract is primarily composed of large-molecule, highly polar, water-soluble components, while the traditional Chinese medicine essential oil is primarily composed of small-molecule, highly volatile, lipid-soluble terpenes. The two are not simply superimposed, but rather, based on complementary pharmacodynamics, synergistic pharmacokinetics, and regulation of the skin microenvironment, construct a multi-dimensional treatment system. Its technical characteristics and application value can be described from the following four aspects.

[0048] (1) Pharmacokinetic level: Opening channels to promote infiltration and storage for slow release, achieving a balance between rapid and long-term effects.

[0049] From the perspective of mechanism of action, the ethanol extracts of traditional Chinese medicine compound preparations contain active ingredients such as berberine alkaloids, flavonoid glycosides, and organic acids. These ingredients have relatively large molecular weights and strong water solubility, making it difficult for them to penetrate the stratum corneum barrier, resulting in low transdermal efficiency. The peppermint essential oil used in this invention has menthol as its main active ingredient, a widely used natural transdermal permeation enhancer that can reversibly alter the lipid arrangement of the stratum corneum, increase intercellular spaces, and open skin permeation channels. The terpenoid components in patchouli and lavender essential oils can enhance the solubility of active ingredients in the stratum corneum, further improving the transdermal performance of the drug.

[0050] From the perspective of compatibility analysis, this formulation uses a microemulsion system with a particle size of less than 100nm as a carrier. Menthol can promote the penetration of the compound extract into the deep lesions such as hair follicles and sebaceous glands. At the same time, the mixed essential oils composed of lavender essential oil, peppermint essential oil, and patchouli essential oil in the formula, together with baobab oil, form an oil phase matrix that can form a drug reservoir on the epidermis, allowing the active ingredients to be released slowly and continuously, reducing the stimulation of the skin by instantaneous high concentrations of drugs, and balancing the speed of drug onset and duration of action.

[0051] (2) Pharmacodynamics: Multi-target coverage, addressing both symptoms and root cause, achieving synergistic effects of anti-inflammatory, antibacterial, and oil-controlling effects.

[0052] Targeting the core inflammatory and infectious pathological mechanisms of acne: Compound extracts of Coptis chinensis and Taraxacum mongolicum can regulate cellular inflammatory signaling pathways, inhibit NF-κB activation, and reduce the expression of inflammatory factors such as TNF-α and IL-6. They also exhibit certain antibacterial activity against Propionibacterium acnes, with the antibacterial effect mainly related to the alkaloid components in the formula. Lavender essential oil and patchouli essential oil can downregulate the expression of the COX-2 inflammatory pathway and disrupt bacterial biofilms, thus alleviating the problem of bacterial resistance. The combined use of these two ingredients can broaden the scope of anti-inflammatory and antibacterial effects, while inhibiting bacterial proliferation and abnormal inflammatory responses, reducing the limitations and risk of drug resistance associated with single-drug use.

[0053] For issues such as abnormal sebum secretion and excessive follicular keratosis: Patchouli alcohol in patchouli essential oil has 5α-reductase inhibitory activity, which can reduce the production of dihydrotestosterone, decrease its stimulating effect on sebaceous glands, and regulate abnormal sebum secretion; pollen protein in trichosanthes root pollen and paeoniflorin in peony root can regulate skin lipid metabolism and improve follicular keratosis by modulating the IGF-1 signaling pathway. Baobab oil contains more than 30% linoleic acid, which can supplement essential fatty acids for the skin, repair damaged skin barriers, and alleviate excessive follicular keratosis. The synergistic effect of these components can form a step-by-step intervention model of "traditional Chinese medicine regulating metabolism, essential oil inhibiting secretion, and lipid barrier repair".

[0054] (3) Safety aspect: Reduced toxicity and increased efficacy, improved skin feel, natural ingredients replace chemical excipients to reduce the risk of irritation.

[0055] Traditional topical transdermal formulations often use chemical penetration enhancers such as azone and dimethyl sulfoxide, which may cause skin irritation such as redness, stinging, and peeling with long-term use. This invention uses a natural compound system of menthol and 1,3-propanediol to replace chemical penetration enhancers, effectively reducing skin irritation. The high proportion of lavender essential oil in the formula has calming and anti-inflammatory effects, promotes epithelial cell repair, alleviates the mild skin warming reaction caused by peppermint and patchouli, repairs minor skin damage, reduces pigmentation, and lowers the probability of acne scars.

[0056] Analysis of the micro-regulatory mechanism of the formulation shows that saponins from Gleditsia sinensis can help unclog hair follicles and promote the discharge of pus, while pollen polysaccharides can form a bioadhesive protective film on the skin surface and repair wounds. The synergistic effect of the two can alleviate discomfort such as dry skin, peeling, and tightness caused by long-term external use of potent heat-clearing ingredients, and improve the tolerability and safety of the preparation for external use.

[0057] This invention extends the traditional Chinese medicine concept of "prevention of disease" to the fields of skin repair and mental well-being. The aromatic components of lavender essential oil can regulate the human HPA axis through the olfactory pathway, alleviating anxiety in acne patients and improving neurogenic inflammation induced by emotional stress, thus achieving simultaneous intervention in skin lesions and mental and physical well-being. The formulation uses carbomer U20 and triethanolamine to prepare a microemulsion gel form, which has good spreadability and breathability, a gentle and comfortable feel on the skin, and can improve patient compliance. Compared with traditional powders and ointments, it has certain dosage form advantages.

[0058] In summary, this invention is based on the traditional Chinese medicine theory of "combining clearing and penetrating, and using both cold and warming methods" in its formulation, and combines modern natural product chemistry and nano-transdermal delivery technology to construct a novel topical intervention system for acne. Specifically, the extracts of the traditional Chinese medicine compound exert long-lasting detoxifying, blood-cooling, and stasis-removing effects, focusing on treating the root cause; the essential oil components of the traditional Chinese medicine exert rapid transdermal, purifying, and repairing effects, focusing on symptomatic improvement of local symptoms; and baobab oil and the microemulsion system serve as carriers for barrier repair and targeted delivery.

[0059] This formulation improves upon the shortcomings of traditional Chinese medicine topical preparations, such as low transdermal efficiency, slow onset of action, and high irritation. Through multi-target and multi-pathway synergistic intervention, it achieves comprehensive effects of anti-inflammation, antibacterial activity, oil control, and skin repair. The formulation uses all natural components to replace chemical penetration enhancers, combined with the skin-repairing properties of essential oils. While ensuring therapeutic efficacy, it also improves the safety and comfort of long-term topical use, providing a feasible technical approach for the modernization and precision development of traditional Chinese medicine topical preparations.

[0060] (4) Advantages of microemulsion gel formulation.

[0061] Microemulsion gels, as a novel transdermal drug delivery system, combine the advantages of both microemulsions and gels: they significantly improve the solubility and formulation stability of traditional Chinese medicine essential oils and extracts, effectively preventing the loss of volatile components; and their three-dimensional network structure forms a protective film on the skin surface, prolonging drug retention time for sustained release and ensuring stable and lasting efficacy. Simultaneously, this dosage form improves the adhesion and spreadability of microemulsions, exhibiting high transdermal absorption, large dermal storage capacity, high drug loading, and excellent biocompatibility. Furthermore, it is convenient to use, easy to clean, and simple to prepare, thereby enhancing efficacy while improving patient compliance and providing an efficient carrier for the transdermal delivery of active ingredients in traditional Chinese medicine.

[0062] As verified by the in vitro antibacterial experiment in Example 2, the minimum inhibitory concentration (MIC) of the herbal microemulsion gel of the present invention against Propionibacterium acnes, calculated as the herbal compound extract, is 10 mg / mL (see Table 8 for the results of combined drug use), confirming that it has definite anti-Propionibacterium acnes activity.

[0063] In a rabbit ear acne model, the high-dose group of the microemulsion gel (200µL / time / day) significantly reduced the serum levels of TNF-α, IL-6, and IL-1β (P values ​​<0.0001, <0.01, and <0.01, respectively), and the inhibitory effect on the three factors was not statistically different from that of the positive control drug adapalene gel (P>0.05).

[0064] Western blot analysis showed that the microemulsion gel could dose-dependently restore the significantly reduced MFGE8 protein level in acne lesions, with the medium-dose group (100 µL / time / day) P<0.05 and the high-dose group (200 µL / time / day) P<0.01. Moreover, the upregulation effect of the high-dose group was not significantly different from that of the positive control drug adapalene gel (P>0.05). Beneficial effects

[0065] Compared with the prior art, the present invention has the following outstanding substantive features and significant progress.

[0066] (1) Prescription innovation: For the first time, Chinese herbal compound extracts and Chinese herbal essential oils are combined in a microemulsion gel system to achieve synergistic function of the two components of "extract + essential oil". The Chinese herbal compound extract provides systemic anti-inflammatory and immunomodulatory activities, while the Chinese herbal essential oil provides antibacterial and transdermal penetration-enhancing activities. The two components complement each other and enhance each other's effects, reflecting the scientific connotation of the traditional Chinese medicine "compound formulation" and the organic combination of modern formulation technology.

[0067] (2) Mechanism innovation: This invention fully verifies that topical Chinese medicine preparations treat acne through the pathway of "MFGE8 upregulation → inhibition of pro-inflammatory factor release → reduction of acne inflammation". As a key inflammatory remission bridging molecule, the pharmacological role of MFGE8 in acne treatment has not been fully explored and verified before, and this invention fills this gap.

[0068] (3) Efficacy advantages: In the rabbit ear acne model, the efficacy indicators of the Chinese herbal microemulsion gel of the present invention were systematically confirmed by multiple dimensions, from ear swelling, histopathology, serum inflammatory factors (TNF-α, IL-6, IL-1β) to MFGE8 protein expression, which reached the non-inferiority level of the first-line drug adapalene gel, providing high-quality evidence support for the clinical application of Chinese herbal external preparations.

[0069] (4) Comprehensive performance advantages: The performance comparison of the microemulsion gel of traditional Chinese medicine in this invention with conventional external preparations of traditional Chinese medicine and adapalene in the prior art is shown in Table 7.

[0070] Table 7. Performance comparison of the herbal microemulsion gel of the present invention with existing technology products. Dosage form Ointments, lotions, regular gels gel Microemulsion gel Transdermal efficiency Low medium High (microemulsion solubilization and penetration enhancement + intradermal reservoir) Targeted pore cleansing none none have Mechanism of action Vague, mostly based on experience Single target (RAR receptor) Multi-target (antibacterial + anti-inflammatory + MFGE8↑) Irritation and safety Different Common symptoms include dryness, erythema, and desquamation. No stimulation was observed in any of the three stimulation tests. Drug resistance risk Low none Low

[0071] As shown in Table 7, the herbal microemulsion gel of the present invention is superior to conventional herbal topical preparations and adapalene in terms of transdermal efficiency, pore targeting, irritation and safety, and has a low risk of drug resistance.

[0072] In summary, this invention provides a traditional Chinese medicine microemulsion gel with a scientifically formulated composition, standardized preparation process, clear mechanism of action, and efficacy that is non-inferior to first-line clinical drugs while exhibiting significantly superior safety. It effectively overcomes the shortcomings of existing acne treatment agents, such as high irritation, easy drug resistance, and unclear mechanism of action, and possesses significant clinical application and industrial transformation value. Attached Figure Description

[0073] Figure 1 This is a particle size distribution diagram of the traditional Chinese medicine microemulsion gel obtained in Example 1 of the present invention.

[0074] Figure 2a This is a bar chart showing the thickness of rabbit ears in each group during the early stage (day 0) of rabbit ear acne model creation in Example 3 of the present invention.

[0075] Figure 2bThis is a bar chart showing the thickness of rabbit ears in each group during the mid-stage of modeling the rabbit ear acne model in Example 3 of the present invention (day 14, i.e., after the coal tar coating was completed).

[0076] Figure 2c This is a bar chart showing the thickness of rabbit ears in each group during the later stage of rabbit ear acne model establishment (after drug administration) in Example 3 of the present invention.

[0077] Figure 3a This is a micrograph (×400x) of HE-stained pathological section of rabbit ear tissue from the blank group in Example 3 of the present invention.

[0078] Figure 3b This is a micrograph (×400x) of HE-stained pathological section of rabbit ear tissue from the model group in Example 3 of this invention.

[0079] Figure 3c This is a micrograph (×400x) of HE-stained pathological section of rabbit ear tissue from the adapalene gel positive control group in Example 3 of the present invention.

[0080] Figure 3d This is a micrograph (×400x) of HE-stained pathological section of rabbit ear tissue from the low-dose group treated with microemulsion gel in Example 3 of the present invention.

[0081] Figure 3e This is a micrograph (×400x) of HE-stained pathological section of rabbit ear tissue from the medium-dose group treated with microemulsion gel in Example 3 of the present invention.

[0082] Figure 3f This is a micrograph (×400x) of HE-stained pathological section of rabbit ear tissue from the high-dose group treated with microemulsion gel in Example 3 of the present invention.

[0083] Figure 4a The bar chart shows the ELISA detection of TNF-α levels in rabbit serum in each group in Example 3 of this invention (compared with the model group, ****P<0.0001).

[0084] Figure 4b The bar chart shows the ELISA detection of IL-6 levels in rabbit serum in each group in Example 3 of this invention (**P<0.01 compared with the model group).

[0085] Figure 4c The bar chart shows the ELISA detection of IL-1β levels in rabbit serum of each group in Example 3 of this invention (**P<0.01 compared with the model group).

[0086] Figure 5a This is a Western blot diagram showing the expression of MFGE8 protein in rabbit ear tissues of each group in Example 3 of the present invention (repeated 1).

[0087] Figure 5b This is a Western blot diagram showing the expression of MFGE8 protein in rabbit ear tissues of each group in Example 3 of the present invention (repeated 2 times).

[0088] Figure 5c This is a Western blot diagram showing the expression of MFGE8 protein in rabbit ear tissues of each group in Example 3 of the present invention (repeated 3 times).

[0089] Figure 6 The image shows a gray-scale quantitative bar chart of MFGE8 protein expression in rabbit ear tissues of each group in Example 3 of this invention (compared with the model group, **P<0.01, *P<0.05). Detailed Implementation

[0090] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but the implementation of the present invention is not limited thereto. The embodiments are for illustrative purposes only and do not constitute any limitation on the scope of protection of the present invention. After reading this specification, those skilled in the art can make appropriate adjustments or modifications to the present invention, all of which are covered within the scope defined by the claims of this application. Example

[0091] Example 1 Preparation of microemulsion gels made from traditional Chinese medicine.

[0092] The formulation composition is as follows, based on the preparation of 100g of microemulsion gel: 4.0g of freeze-dried powder of compound Chinese medicine extract, 0.64g of Chinese medicine essential oil, 3.36g of oil phase matrix (baobab oil), 9.6g of polyoxyethylene (40) hydrogenated castor oil, 3.2g of Span 80, 3.2g of co-surfactant (1,3-propanediol), 1.0g of gel matrix (carbomer U20), 1.5g of preservative, appropriate amount of triethanolamine, and purified water added to 100g.

[0093] The above-mentioned 0.64g Chinese herbal essential oil is composed of 0.36g lavender essential oil, 0.16g patchouli essential oil, and 0.12g peppermint essential oil.

[0094] The above-mentioned preservative is a mixture of p-hydroxyacetophenone, 1,2-hexanediol and 1,2-pentanediol in a mass ratio of 3:8:9.

[0095] S01: Weigh 30g of Coptis chinensis, 30g of Forsythia suspensa, 30g of Paeonia lactiflora, 60g of Taraxacum mongolicum, 20g of Gleditsia sinensis thorns, and 30g of Trichosanthes kirilowii (total 200g). Add 10 times the amount of 65% ethanol, soak for 1 hour, and reflux extract three times, 2 hours each time, using 10 times the amount of 65% ethanol each time. Filter the extract and combine the filtrates. Concentrate under reduced pressure to 0.42-0.46g of raw herbs per mL. Refrigerate at 3℃-5℃ for 24 hours. Remove the insoluble precipitate at the bottom, place in an evaporating dish, freeze-dry, pulverize, and seal for storage. Three parallel extractions (200g of herbs each) were performed using this method, yielding 50.6g, 49.2g, and 49.8g of freeze-dried powder, respectively, with an average extraction rate of 24.93%.

[0096] S02: Take 0.36g of lavender essential oil, 0.16g of patchouli essential oil and 0.12g of peppermint essential oil and mix them evenly. Add 3.36g of baobab oil and stir well to obtain 4.0g of oil phase containing Chinese herbal essential oils.

[0097] Lavender essential oil was prepared in-house as follows: Lavender herbs cut into 0.5cm sections were soaked in 10 times their volume of water at 50℃ for 1 hour, followed by ultrasonic extraction at 50℃ and 200W for 20 minutes, and then steam distillation for 90 minutes. The essential oil was collected and dehydrated using anhydrous Na2SO4. Three parallel extractions were performed using this method, yielding 1.20mL, 1.25mL, and 1.25mL of lavender essential oil respectively, with an average extraction rate of 2.47%.

[0098] Peppermint essential oil was prepared by the following method: 100g of peppermint herbs were coarsely ground and placed in a 3L round-bottom flask. 1650mL of water was added and the mixture was soaked for 1 hour. The mixture was then ultrasonically extracted for 30 minutes at 45℃ and 300W, followed by steam distillation for 5 hours. The essential oil was collected and dehydrated using anhydrous Na2SO4. Three parallel extractions yielded 0.41mL, 0.40mL, and 0.42mL of peppermint essential oil, respectively, with an average extraction rate of 0.41%.

[0099] Patchouli essential oil was prepared by the following method: 100g of patchouli herb was crushed into coarse powder and placed in a 3L round-bottom flask. 1650mL of water was added and the mixture was soaked for 1 hour. The mixture was then ultrasonically extracted for 30 minutes at 45℃ and 300W, followed by steam distillation for 5 hours. The essential oil was collected and dehydrated with anhydrous Na2SO4. Three parallel extractions yielded 0.62mL, 0.64mL, and 0.61mL of patchouli essential oil, respectively, with an average extraction rate of 0.623%.

[0100] S03: Take 9.6g of polyoxyethylene (40) hydrogenated castor oil, 3.2g of Span 80 and 3.2g of 1,3-propanediol, mix them evenly to obtain 16.0g of mixed surfactant.

[0101] SO4: Under stirring conditions, 16.0g of the mixed surfactant obtained in step S03 was placed in a container, and 4.0g of the oil phase containing Chinese herbal essential oil obtained in step S02 was slowly added dropwise. After stirring evenly, the resulting oil phase mixture was added dropwise to 20g of purified water and stirred continuously to form a transparent and clear O / W microemulsion.

[0102] S05: Under stirring conditions, add 1.0g of carbomer U20 in portions to the O / W microemulsion obtained in step S04, stir thoroughly to disperse, and let it swell at room temperature for 48 hours. Then add 4.0g of the lyophilized powder of the traditional Chinese medicine compound extract obtained in step S01, stirring continuously until completely dissolved. Add an appropriate amount of triethanolamine to adjust the pH to 5.5-6.5, add 1.5g of preservative (a mixture of p-hydroxyacetophenone, 1,2-hexanediol, and 1,2-pentanediol in a mass ratio of 3:8:9), and finally add purified water to 100g. Stir evenly to obtain an orange-yellow, semi-transparent, clear, semi-solid microemulsion gel with a characteristic aromatic odor.

[0103] An appropriate amount of the herbal microemulsion gel obtained in Example 1 was taken, and its particle size distribution was determined using a dynamic light scattering particle size analyzer. The results are shown in the figure. Figure 1 .Depend on Figure 1 It can be seen that the particle size distribution of the herbal microemulsion gel obtained by the present invention is concentrated, with a particle size of 20nm-100nm.

[0104] Example 2 In vitro antibacterial activity test.

[0105] Preparation of the combined microemulsion of traditional Chinese medicine and essential oil: Following the method of Example 1, in step S05, purified water was added to a final volume of 50g to obtain the combined microemulsion gel of traditional Chinese medicine and essential oil (containing 80mg / g of traditional Chinese medicine extract and 12.8mg / g of traditional Chinese medicine essential oil).

[0106] Preparation of microemulsion containing only traditional Chinese medicine compound extract: A mixed surfactant was prepared according to step S03 of Example 1; under stirring conditions, 20g of water was added to the obtained mixed surfactant and stirred continuously. Then, 4.0g of the lyophilized powder of the traditional Chinese medicine compound extract prepared according to step S01 of Example 1 was added while stirring until completely dissolved. An appropriate amount of triethanolamine was added dropwise to adjust the pH to 5.5-6.5, and 1.5g of preservative (a mixture of p-hydroxyacetophenone, 1,2-hexanediol, and 1,2-pentanediol in a mass ratio of 3:8:9) was added. Finally, purified water was added to a final volume of 50g, and the mixture was stirred evenly to obtain a microemulsion containing only the traditional Chinese medicine extract (containing 80mg / g of traditional Chinese medicine extract).

[0107] Preparation of single-use mixed essential oil microemulsion: Prepare mixed surfactant and O / W type microemulsion according to the steps S03 and SO4 in Example 1; add water to make up to 50g, stir evenly, and obtain single-use mixed essential oil microemulsion (containing 12.8mg / g of Chinese herbal essential oil).

[0108] The effects of the following microemulsions on Propionibacterium acnes (TCM) were determined and compared using the 96-well plate micro-broth dilution method (6 concentration gradients per group, 4 replicates). These microemulsions included: a combined TCM-essential oil microemulsion (containing 80 mg / g of TCM extract and 12.8 mg / g of TCM essential oil), a TCM extract microemulsion (containing only 80 mg / g of TCM extract), and an essential oil microemulsion (containing only 12.8 mg / g of TCM essential oil). Propionibacterium acnes ATCC 11827, final concentration of bacterial suspension approximately 6.8 × 10⁻⁶ 5 The minimum inhibitory concentration (MIC) of clindamycin hydrochloride gel (CFU / mL, anaerobic culture at 37℃ for 48 h) was determined by visual observation, with the lowest concentration showing no visible bacterial growth as the MIC. The effect of combined drug therapy was evaluated using clindamycin hydrochloride gel as a positive control. The results are shown in Table 8.

[0109] Table 8. Comparison of the minimum inhibitory concentration (MIC) of the herbal microemulsion gel of the present invention (microemulsion of herbal compound extract-mixed essential oil), microemulsion of herbal compound extract alone, and microemulsion of mixed essential oil alone against Propionibacterium acnes. Positive test result (clindamycin hydrochloride gel) 0.0195 1.25 Microemulsion of Chinese herbal compound extracts and mixed essential oils 10g of compound extract of traditional Chinese medicine; 1.6g of essential oil. combination therapy Microemulsion of Chinese herbal compound extracts 20 Calculated by Chinese herbal extracts Single use of blended essential oil microemulsion 6.4 Based on blended essential oils

[0110] As shown in Table 8, the minimum inhibitory concentration (MIC) of the combined microemulsion of traditional Chinese medicine compound extract and essential oil obtained in Example 1 against Propionibacterium acnes was 10 mg / mL, based on the traditional Chinese medicine compound extract, confirming that the traditional Chinese medicine microemulsion gel of the present invention has definite anti-Propionibacterium acnes activity.

[0111] FIC Index Calculation and Joint Effect Determination Calculated according to the internationally accepted FIC index formula: FIC = MIC of combined Chinese herbal medicine / MIC of single Chinese herbal medicine + MIC of combined essential oils / MIC of single or mixed essential oils In this experiment, FIC = 10 / 20 + 1.6 / 6.4 = 0.5 + 0.25 = 0.75, which is determined to be an additive effect.

[0112] Based on the above experimental results, the traditional Chinese medicine compound microemulsion gel of the present invention has the following substantial technical breakthroughs and significant progress.

[0113] 1. A technological breakthrough was achieved in "reducing quantity without reducing efficiency". While maintaining equivalent antibacterial efficacy, this invention, in combination with microemulsions, achieves a significant dose reduction compared to single-drug administration: The effective dose of the herbal extract was reduced by 50% (from 20 mg / g to 10 mg / g). The amount of blended essential oils added was reduced by 75% (from 6.4 mg / g to 1.6 mg / g). Four independent repeated experiments verified that the reduced-dose combination group had the same antibacterial efficacy as the single-dose group (FIC=0.75, which is an additive effect), proving that the reduction in dosage of the present invention is a scientific reduction that does not reduce efficacy, rather than a simple dilution.

[0114] 2. Solved the problems of safe use of facial essential oils and the solubility of traditional Chinese medicine extracts in microemulsion gels. While essential oils are recognized for their anti-inflammatory, repairing, and soothing properties, their use on the face, especially in the form of a face mask, is strictly limited. Unlike regular creams, face masks are applied to the face for extended periods, over large areas, and in a closed manner, increasing skin permeability and requiring far gentler ingredients than ordinary skincare products. Therefore, using high concentrations of essential oils in face masks can easily cause skin irritation, allergic reactions, and other adverse reactions.

[0115] Using essential oils alone for antibacterial purposes requires a concentration as high as 6.4 mg / g, which may exceed the skin's tolerance threshold in mask formulations. This invention, through the scientific blending of traditional Chinese medicine and essential oils, reduces the amount of essential oil added to 1.6 mg / g, only one-quarter of the MIC of a single ingredient, and far lower than the commonly used amount for facial application in the industry. At this low concentration, the essential oil avoids the risk of irritation while retaining its independent skincare functions of soothing and repairing, successfully solving the dilemma in mask formulations where "low concentrations of essential oils are ineffective, while high concentrations are irritating."

[0116] Regarding the solubility of traditional Chinese medicine (TCM) extracts: TCM extracts exhibit a definite upper limit of solubility in microemulsion gel systems. Experimental results show that when the concentration of the six-herb compound extract used in this invention exceeds 40 mg / g in this system, a small amount of precipitation occurs, leading to decreased product stability, uneven distribution of active ingredients, and consequently affecting the accuracy and reproducibility of efficacy. However, in vitro experiments indicate that a concentration of 20 mg / g is required to achieve the minimum inhibitory concentration (MIC) when using TCM extracts alone. While this concentration is within the upper limit of solubility, it is close to the saturation boundary, leaving very limited room for formulation design. This invention, through the additive effect of TCM and essential oils (FIC=0.75), reduces the effective inhibitory concentration of the TCM extract from 20 mg / g to 10 mg / g, only 50% of the MIC of a single herb. This reduction ensures that the working concentration of the TCM extract in the formulation is far below its solubility limit, fundamentally avoiding the risk of precipitation and ensuring the long-term stability and dosage uniformity of the microemulsion gel product.

[0117] Overall Results: By simultaneously addressing the two technical challenges mentioned above, the herbal-essential oil microemulsion gel mask of this invention achieves a dual reduction in both essential oil concentration (1.6 mg / g) and herbal concentration (10 mg / g, based on MIC). The reduction in essential oil usage ensures the mask's skin safety and gentleness, while the reduction in herbal concentration guarantees the product's physical stability and batch-to-batch consistency within the microemulsion gel system. This synergy allows the product to maintain equivalent or even superior antibacterial efficacy while possessing the comprehensive advantages of high safety, high stability, and multifunctionality—a breakthrough that existing single-ingredient or simply mixed products cannot achieve.

[0118] 3. It achieves a combined function of "antibacterial + repair". The herbal compound microemulsion gel of this invention, containing extracts of traditional Chinese medicine and mixed essential oils, is not a simple superposition of two known ingredients, but rather a multi-layered efficacy system constructed based on a deep division of the functional roles of each component. Traditional Chinese medicine extracts: These extracts play a crucial role in antibacterial and anti-inflammatory function. Berberine, the main active ingredient in Coptis chinensis, has been shown to significantly downregulate the levels of pro-inflammatory factors such as TNF-α and IL-6 by inhibiting the NF-κB signaling pathway. Forsythia suspensa contains forsythoside A, which can simultaneously inhibit the activation of the NF-κB pathway and the NLRP3 inflammasome, exerting a dual anti-inflammatory effect. Dandelion is rich in phenolic acids such as chlorogenic acid, which has a clear inhibitory effect on inflammatory mediators such as COX-2. Paeonia lactiflora contains paeoniflorin, which exhibits significant anti-inflammatory activity in various inflammatory models by regulating the NF-κB pathway. The combined use of these herbs, through multi-target and multi-pathway synergy, achieves potent inhibition of Propionibacterium acnes and comprehensive regulation of related inflammatory responses.

[0119] Blended essential oils: At extremely low concentrations, through their independent molecular mechanisms, they impart additional functions that single-use herbal extracts or blended essential oils lack or have only slightly enhanced properties. Linalool, the main component of lavender essential oil, can alleviate skin discomfort by inhibiting TRPV1 receptors, producing analgesic and antipruritic effects. Simultaneously, lavender essential oil itself has been shown to promote wound healing by accelerating granulation tissue formation. Patchouli essential oil's core component, patchouli alcohol, effectively inhibits the expression of COX-2 and iNOS, exerting anti-inflammatory effects. Peppermint essential oil's core component, menthol, is a specific agonist of the TRPM8 cold receptor, producing an immediate cooling sensation. As a recognized natural penetration enhancer, it can also assist in the transdermal absorption of other active ingredients.

[0120] This complementary design, which uses traditional Chinese medicine as the main antibacterial agent and essential oils as the auxiliary repair agent, enables the single product of the present invention, a traditional Chinese medicine compound microemulsion gel containing traditional Chinese medicine compound extracts and mixed essential oils, to simultaneously cover the two key aspects of acne treatment: "antibacterial and anti-inflammatory" and "soothing and repairing." This is a comprehensive treatment solution that cannot be achieved by single-ingredient products or simple mixed products in the prior art.

[0121] 4. The experimental design is rigorous, and the results are reproducible. This invention uses three parallel microemulsion systems for comparison. The excipient systems of the three microemulsions are completely identical (baobab oil, polyoxyethylene hydrogenated castor oil, 1,3-propanediol, and Span 80), with consistent particle size and stability, thus minimizing the interference of formulation factors on the experimental results. Furthermore, the MIC experiment was independently verified four times, with stable and reliable data and a consistent FIC value of 0.75, demonstrating the scientific rigor and reproducibility of the experimental results.

[0122] Example 3 In vivo pharmacodynamic experiments of a rabbit ear acne model.

[0123] 3.1 New Zealand rabbits were used. Except for the control group, each group applied 0.5 mL of 3% coal tar solution to a 2 cm × 2 cm area on the inner side of the left ear daily for 14 consecutive days. Starting from the 15th day, Propionibacterium acnes solution was injected intradermally every other day until visible cysts appeared on the auricle, indicating successful modeling.

[0124] 3.2 New Zealand rabbits that successfully developed the model were randomly divided into the following 6 groups, with 4 rabbits in each group: blank group (no treatment), model group (no drug administration), positive control group (administered adapalene gel), low-dose microemulsion gel group (L group), medium-dose group (M group), and high-dose group (H group). Each group was administered the drug for 14 consecutive days, once daily, 200 μL each time. Specifically, group H was directly administered the finished microemulsion gel prepared in Example 1 (concentration 40 mg / mL), group M was administered the drug after diluting the blank gel matrix 2 times (concentration 20 mg / mL), and group L was administered the drug after diluting the blank gel matrix 10 times (concentration 4 mg / mL). The positive control group was administered commercially available adapalene gel, with the same administration volume and frequency as the treatment group.

[0125] 3.3 Main Results:

[0126] 3.3.1 Rabbit ear thickness: The thickness of the central part of the drug-coated area in the rabbit ears of each group was measured using vernier calipers at the early stage of modeling (day 0), the middle stage of modeling (day 14, i.e., after the coal tar coating was completed), and the late stage of modeling (after the drug administration was completed). The results are shown in […]. Figure 2a , Figure 2b , Figure 2c .Depend on Figure 2a It can be seen that there was no significant difference in the basic thickness of the rabbit ears among the groups before modeling, making them comparable. Figure 2b It can be seen that after 14 days of continuous application of coal tar, the thickness of rabbit ears in each modeling group was significantly increased compared with the control group, indicating that the modeling was successful. Figure 2c It can be seen that after treatment, the thickness of rabbit ears in group H was significantly reduced compared with that in the model group (P<0.05), and there was no statistical difference compared with the positive control group (P>0.05), indicating that the herbal microemulsion gel of the present invention can effectively improve the swelling of acne lesions.

[0127] 3.3.2 HE Pathology: After drug administration, full-thickness skin tissue from the drug-treated area of ​​rabbit ears in each group was collected, fixed, dehydrated, embedded, sectioned, and stained with hematoxylin and eosin (HE). Histopathological changes were observed under a light microscope (×400x). The results are shown in the figure. Figures 3a-3f .Depend on Figure 3a It can be seen that the epidermal layers of the rabbit ears in the control group were clear, the hair follicles and sebaceous glands had normal structures, and no inflammatory cell infiltration was observed. Figure 3b It can be seen that the ear epidermis of the model group rabbits was significantly thickened, hair follicles were significantly dilated, and there was extensive inflammatory cell infiltration in the dermis. Figure 3c It can be seen that in the positive control group, the epidermal thickness was close to normal, hair follicle dilation was significantly reduced, and inflammatory infiltration was significantly decreased. From Figure 3d It can be seen that the epidermis in the low-dose group still showed some degree of thickening, and while follicular dilation and inflammatory infiltration were reduced compared to the model group, the improvement was limited. Figure 3e and Figure 3f It was found that the epidermal thickening, follicular dilation, and inflammatory infiltration were significantly improved in both the medium and high dose groups, and the skin tissue structure tended to be normal. Furthermore, the improvement effect in the high dose group was superior to that in the medium dose group. These results indicate that the herbal microemulsion gel of this invention can dose-dependently reduce the local inflammatory response and histopathological damage in acne lesions.

[0128] 3.3.3 ELISA Serum Inflammatory Factors: After drug administration, blood was collected from the heart and serum was separated. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the serum of rabbits in each group were detected by enzyme-linked immunosorbent assay (ELISA). Results are shown below. Figure 4a , Figure 4b , Figure 4c .Depend on Figures 4a-4c It can be seen that the levels of the three inflammatory factors in the model group were significantly higher than those in the blank group; the H group could significantly or significantly inhibit the release of TNF-α (P<0.0001), IL-1β (P<0.01) and IL-6 (P<0.01), and the inhibitory effect of the H group on the three factors was not statistically different from that of the positive control group (P>0.05), indicating that the herbal microemulsion gel of the present invention can exert anti-inflammatory effect by inhibiting the level of systemic inflammatory factors.

[0129] 3.3.4 Western blot MFGE8: After drug administration, skin tissue from the drug-treated areas of rabbit ears in each group was collected, and total protein was extracted. The expression level of epidermal growth factor 8 (MFGE8) protein in milk fat globules was detected by Western blot, with GAPDH as an internal control, and quantitative analysis was performed using grayscale values. Representative bands from the Western blot are shown below. Figures 5a-5c (Three repeated experiments), the quantitative statistical results of grayscale are shown in [the table]. Figure 6 .Depend on Figures 5a-5c and Figure 6 It can be seen that the expression level of MFGE8 protein in the model group was significantly lower than that in the blank group. After treatment, the expression of MFGE8 protein in the M group (P<0.05) and the H group (P<0.01) was significantly upregulated in a dose-dependent manner, and the upregulation effect in the H group was not significantly different from that in the positive control group (P>0.05). This indicates that the herbal microemulsion gel of the present invention can promote the resolution of inflammation by restoring the downregulated MFGE8 protein level in acne lesions.

[0130] Example 4 Safety evaluation experiment.

[0131] In accordance with the relevant requirements of the "Biological Evaluation of Medical Devices" series of standards and the "Cosmetic Safety Technical Specifications", the traditional Chinese medicine microemulsion gel obtained in Example 1 was subjected to multiple skin irritation tests, acute skin irritation tests, and acute eye irritation tests to evaluate its topical safety. The results are shown in Table 9.

[0132] Repeated skin irritation experiments: An appropriate amount of the herbal microemulsion gel prepared in Example 1 of this invention was applied to the skin of six clean-grade healthy New Zealand rabbits once a day for 14 consecutive days. The degree of erythema, keratosis, and edema at the application site was observed and scored daily to evaluate its irritation.

[0133] Acute skin irritation test: Take an appropriate amount of the traditional Chinese medicine microemulsion gel prepared in Example 1 of this invention, apply it to the skin of 6 clean-grade healthy New Zealand rabbits, cover with gauze and cellophane, leave for 4 hours, remove the residual test substance with warm water after application, and observe its irritation after 1 hour, 24 hours, 48 ​​hours and 72 hours respectively.

[0134] Acute eye irritation test: Take an appropriate amount of the herbal microemulsion gel prepared in Example 1 of this invention and instill it into the eye of a domestic rabbit without eye disease. Close the eye for 1 second, and at 30 seconds, rinse with a sufficient amount of water at a relatively fast flow rate that will not cause damage to the animal's eye for 30 seconds. Examine the animal's eye with a handheld slit lamp at 1, 24, 48, and 72 hours after instillation, as well as on the 4th and 7th days. After 24 hours of observation and recording, further examination is performed using sodium fluorescein.

[0135] Table 9 Safety Evaluation Test Results Multiple skin irritation tests Six New Zealand rabbits were treated with the treatment for 14 consecutive days. Non-irritating (score 0) Acute skin irritation test Six New Zealand rabbits were treated with the patch for 4 hours and observed for 3 days. Non-irritating (score 0) Acute eye irritation test Six New Zealand rabbits were given eye drops and observed for seven days. Non-irritating (score 0) As shown in Table 9, the herbal microemulsion gel of the present invention exhibited no irritation in multiple skin irritation, acute skin irritation and acute eye irritation tests, demonstrating good external safety.

[0136] Example 5 Preliminary quality evaluation of traditional Chinese medicine microemulsion gel.

[0137] Three batches of the traditional Chinese medicine microemulsion gel described in this invention were continuously prepared according to the method in Example 1 of this application, with batch numbers 20260119, 20260120, and 20260121, respectively. Preliminary quality evaluation was conducted in accordance with the relevant provisions (General Rule 0114) of the "Product Quality Standard (Draft)" and the Gel Subsection of Part IV of the 2025 Edition of the Chinese Pharmacopoeia.

[0138] 1. Appearance: This product should be an orange-yellow, semi-transparent gel. Test results: At room temperature, all three batches were orange-yellow, semi-transparent, with a fine texture, uniform gloss, no layering, no visible particles, and moderate fluidity—a microemulsion gel. Result: All three batches met the requirements.

[0139] 2. Uniformity: Take appropriate amounts of samples from three batches of products at room temperature and apply them to the skin. There is no gritty feeling. Then apply them to a glass plate. The gel is fine and glossy, with no visible particles, and the gel consistency is moderate, making it easy to spread. Meets the requirements.

[0140] 3. Acidity: Take 1g of each of three batches of this product and place them in measuring cups. Determine the acidity according to Appendix VI H of the Chinese Pharmacopoeia (2020 Edition), Part IV. The results showed that the pH values ​​of the three batches of samples were 6.16, 6.17, and 6.17, respectively, which were within the range of 5.5-6.5 and met the requirements.

[0141] 4. Content determination.

[0142] Referring to the methods for determining the content of paeoniflorin, forsythoside, and berberine hydrochloride in the microemulsion gel of this invention, as described in Part I of the 2025 edition of the Chinese Pharmacopoeia, a method for determining the content of paeoniflorin, forsythoside, and berberine hydrochloride in the microemulsion gel of this invention was established, and the method was validated. The contents of paeoniflorin, forsythoside, and berberine hydrochloride in three batches of microemulsion gel of this invention produced in successive trials were determined, and the results are shown in Table 10.

[0143] Table 10 shows the content determination results of samples from 10 batches.

[0144] 5. Stability test (influencing factor test).

[0145] 5.1 Centrifugal Stability Two portions each of the three batches of traditional Chinese medicine microemulsion gel samples from this application (batch numbers 20260119, 20260120, and 20260121, 1.40 g each) were placed in centrifuge tubes and centrifuged at 12000 r·min⁻¹. -1 After centrifugation for 15 minutes, no stratification was observed in any of the three batches of products.

[0146] 5.2 Heat and Cold Resistance Tests: Six samples of the herbal microemulsion gel from batch number 20260119, each weighing 1.4 g, were taken and placed in centrifuge tubes. Three samples were placed in a 40℃ incubator for 24 hours and then allowed to cool to room temperature naturally. The other three samples were placed in a -20℃ refrigerator for 24 hours and then allowed to warm to room temperature naturally. The centrifuge tubes were then heated at 12000 r·min. -1 After centrifugation for 15 minutes, the samples were observed. Results: No changes or stratification were observed in the six samples. The pH values ​​were measured to be 6.163±0.0058 and 6.173±0.00093, respectively, and no significant changes were observed.

[0147] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Any technical solution implemented within the scope of the claims of this application, or any solution made by those skilled in the art using the methods disclosed above, shall fall within the protection scope of the present invention.

Claims

1. A traditional Chinese medicine microemulsion gel for treating acne, characterized in that, The raw and excipient materials used to prepare 100 parts of the aforementioned traditional Chinese medicine microemulsion gel by weight include: 1.0-5.0 parts of traditional Chinese medicine compound extract, 0.5-1.0 parts of traditional Chinese medicine essential oil, 2.0-8.0 parts of oil phase matrix, 5.0-20.0 parts of surfactant A, 2.0-10.0 parts of surfactant B, 2.0-10.0 parts of co-surfactant, 0.5-2.0 parts of gel matrix, and 1.5 parts of preservative. Triethanolamine is added to adjust the pH value to 5.5-6.5, and water is added to make up to 100 parts. The traditional Chinese medicine compound extract is obtained by mixing six traditional Chinese medicines, namely Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii, and extracting, concentrating, drying, and pulverizing them with 65% ethanol; the mass ratio of the six traditional Chinese medicines, namely Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii, is 3:3:3:6:2:

3. The herbal essential oil is made by mixing lavender essential oil, peppermint essential oil and patchouli essential oil, with a mass ratio of 9:4:

3. The oil phase matrix is ​​baobab oil; The surfactant A is polyoxyethylene (40) hydrogenated castor oil, and the surfactant B is Span 80; The co-surfactant is 1,3-propanediol; The gel matrix is ​​Carbomer U20; The preservative is one or any two or three of p-hydroxyacetophenone, 1,2-hexanediol, and 1,2-pentanediol.

2. The traditional Chinese medicine microemulsion gel as described in claim 1, characterized in that, The raw materials and excipients used to prepare 100 parts of the traditional Chinese medicine microemulsion gel by weight include: 4.0 parts of traditional Chinese medicine compound extract, 0.64 parts of traditional Chinese medicine essential oil, 3.36 parts of baobab oil, 9.6 parts of polyoxyethylene (40) hydrogenated castor oil, 3.2 parts of Span 80, 3.2 parts of 1,3-propanediol, 1.0 part of carbomer U20, 1.5 parts of preservative, and added triethanolamine to adjust the pH to 6.0, and water to make up to 100 parts; the preservative is a mixture of p-hydroxyacetophenone, 1,2-hexanediol and 1,2-pentanediol in a mass ratio of 3:8:

9.

3. The traditional Chinese medicine microemulsion gel as described in claim 1, characterized in that, The preparation method of the traditional Chinese medicine compound extract is as follows: Weigh six herbs (Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorns, and Trichosanthes kirilowii) according to a mass ratio of 3:3:3:6:2:3; add 10 times the amount of 65% ethanol and soak for 1 hour; extract by reflux three times, 2 hours each time, using 10 times the amount of 65% ethanol each time; filter the extract and combine the filtrates; concentrate under reduced pressure to a concentration equivalent to 0.42-0.46 g of raw herbs per ml; refrigerate at 3℃-5℃ for 24 hours. Remove the insoluble precipitate at the bottom, place in an evaporating dish, freeze-dry, pulverize, and seal for storage to obtain the final product.

4. The traditional Chinese medicine microemulsion gel as described in claim 1, characterized in that, The lavender essential oil, peppermint essential oil, and patchouli essential oil were obtained by pre-extracting lavender, peppermint slices, and patchouli slices respectively using ultrasonic pre-extraction followed by steam distillation.

5. The traditional Chinese medicine microemulsion gel as described in claim 1, characterized in that, The particle size of the herbal microemulsion gel is 20nm-100nm.

6. The use of the traditional Chinese medicine microemulsion gel as described in claim 1 in the preparation of a medicament for treating acne.

7. The application as described in claim 6, characterized in that, The herbal microemulsion gel exerts its therapeutic effect on acne by upregulating MFGE8 protein expression and inhibiting the release of pro-inflammatory factors TNF-α, IL-6, and IL-1β.

8. A method for preparing a traditional Chinese medicine microemulsion gel as described in claim 1, characterized in that, The steps include: S01. Preparation of compound extract of traditional Chinese medicine: six Chinese herbs, namely Coptis chinensis, Forsythia suspensa, Paeonia lactiflora, Taraxacum mongolicum, Gleditsia sinensis thorn and Trichosanthes kirilowii, were weighed according to the mass ratio of 3:3:3:6:2:

3. They were extracted with 65% ethanol. The extract was freeze-dried to obtain freeze-dried powder of compound extract of traditional Chinese medicine. S02. Preparation of the oil phase containing Chinese herbal essential oils: Take lavender essential oil, peppermint essential oil and patchouli essential oil in a mass ratio of 9:4:3 and mix them well to obtain a mixed essential oil; take 0.5-1.0 parts of the mixed essential oil and add 2.0-8.0 parts of baobab oil to obtain the oil phase containing Chinese herbal essential oils; S03. Preparation of mixed surfactant: Take 5.0-20.0 parts of polyoxyethylene (40) hydrogenated castor oil, 2.0-10.0 parts of Span 80, and 2.0-10.0 parts of co-surfactant (1,3-propanediol), mix them evenly to obtain mixed surfactant; Preparation of S04.O / W type microemulsion: Under stirring conditions, take the mixed surfactant obtained in step S03, add the oil phase containing Chinese herbal essential oil obtained in step S02 dropwise to it, mix well, and then add the resulting mixture dropwise to 20 parts of water to form O / W type microemulsion. S05. Preparation of microemulsion gel: Under stirring conditions, add 0.5-2.0 parts of gel matrix (carbomer U20) to the O / W type microemulsion obtained in step S04 in portions, stir thoroughly, and let it swell fully at room temperature for 48 hours. Then add 1.0-5.0 parts of lyophilized powder of traditional Chinese medicine compound extract obtained in step S01, stirring while adding until completely dissolved. Add triethanolamine to adjust the pH to 5.5-6.5, then add 1.5 parts of preservative, and finally add water to 100 parts. Stir evenly to obtain microemulsion gel.

9. The preparation method according to claim 8, characterized in that, In step S02, the amount of mixed essential oil is 0.64 parts, and the amount of baobab oil is 3.36 parts; in step S03, the amount of polyoxyethylene (40) hydrogenated castor oil is 9.6 parts, the amount of Span 80 is 3.2 parts, and the amount of 1,3-propanediol is 3.2 parts; in step S04, the amount of oil phase containing Chinese herbal essential oil is 4.0 parts, and the total amount of mixed surfactants obtained in step S03 is 16.0 parts; in step S05, the amount of carbomer U20 is 1.0 part, the amount of lyophilized powder of Chinese herbal compound extract is 4.0 parts, and triethanolamine is added to adjust the pH to 6.

0.

10. The preparation method according to claim 8, characterized in that, The particle size of the obtained herbal microemulsion gel is 20nm-100nm.

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