A compound gel for treating arthritis based on the modification of a unique ancient prescription

Abstract

This invention relates to a compound gel for treating joint inflammation based on a modified ancient Chinese medicine formula, belonging to the fields of pharmaceutical preparations and traditional Chinese medicine. The compound gel consists of active ingredient extracts, a poloxamer thermosensitive gel matrix, a penetration enhancer, a humectant, and deionized water. The active ingredient extracts are obtained from *Terminalia chebula*, *Amla emblica*, lavender, wild watermelon, *Artemisia annua*, and chamomile through ultrasonic-microwave coupling extraction. Using ultrasonic-microwave coupling extraction combined with a low-temperature drying process, small-molecule active ingredients are obtained. A body temperature-responsive gel is constructed based on poloxamer 407 / 188, achieving in-situ phase transition on the skin surface and stable sustained release over 6-8 hours, significantly improving transdermal absorption. The gel is combined with an integrated medication container and biomimetic protective gear to form a synergistic drug delivery system, achieving closed-loop controlled release, leak-proof design, and motion adaptation. This gel is non-irritating and non-allergenic, suitable for topical treatment of osteoarthritis, rheumatoid arthritis, and soft tissue injuries caused by cold and dampness in high-altitude regions.

Description

Technical Field

[0001] This invention relates to the fields of pharmaceutical preparations and traditional medicine, specifically a compound gel for treating joint inflammation based on a modified ancient Chinese medicine formula. Background Technology

[0002] Xinjiang's high-altitude regions experience consistently low temperatures and significant diurnal temperature variations. The dry, windy air exacerbates these conditions, leading to chronic cold and dampness affecting joints. Low temperatures cause vasoconstriction around joints, slowing local blood circulation and resulting in the accumulation of metabolic waste in the synovium. The large temperature differences cause repeated contraction and relaxation of ligaments and soft tissues, inducing chronic strain. Furthermore, the prevalence of pastoralism and strenuous outdoor labor among the local population, placing heavy loads on joints, contributes to a significantly higher incidence of cold-dampness-induced osteoarthritis and soft tissue injuries compared to inland areas. Simultaneously, the dry climate of these high-altitude regions results in thicker skin stratum corneum and a weakened skin barrier, hindering drug penetration and easily triggering allergic reactions and redness associated with ordinary plasters. This creates a triple constraint on medication use due to regional disease characteristics, specific skin types, and the demands of different work environments. Maijuni Nugal is a classic Uyghur medicine formula for a honey-based ointment, recorded in the ancient Uyghur medical text "Baidiyi Medicine Book" in 1368 AD, and included in the National Catalogue of Ancient Classic Prescriptions (Second Batch) of Uyghur Medicine. The original formula in ancient texts consists of Terminalia chebula, Phyllanthus emblica, lavender, Polygonum hydropiper, and Cuscuta chinensis, with the core principle of warming the meridians and dispelling cold, clearing abnormal phlegm and black bile, and is used for bone and joint diseases that are prone to occur in high-altitude and cold regions, such as cold-dampness obstruction, cold pain in the joints, stiffness and difficulty in flexion and extension. However, this formula is an oral honey paste dosage form, which has drawbacks such as poor local targeting, slow onset of action, gastrointestinal irritation, and inconvenient storage. Folk external prescriptions contain highly irritating ammoniac and hollyhock seeds, which have poor external compatibility, making it difficult to directly formulate them into medicines. Existing external dosage forms such as ordinary plasters and conventional gels are also not suitable for the characteristics and usage scenarios of people in high-altitude and cold regions. It is necessary to modify the ancient formula based on its theory and develop external drug delivery preparations with specific adaptability to high-altitude and cold regions.

[0003] While traditional oral honey ointments possess the effects of warming the meridians, dispelling cold, and relieving pain, they are limited by their systemic administration mode: after absorption through the gastrointestinal tract, the concentration of the drug distributed to the joint lesions via blood circulation is relatively low, most of the active ingredients are metabolized and consumed by the liver and kidneys, and the amount acting on the synovium and cartilage is limited. The onset time is usually several hours to one to two days, making it difficult to cope with acute cold pain and stiffness in the joints. Long-term oral administration can easily cause gastrointestinal irritation such as abdominal distension and nausea. People in cold and high-altitude areas tend to have weaker spleen and stomach functions and poor tolerance. Traditional honey ointments have a high sugar content, making them unsuitable for arthritis patients with metabolic abnormalities. They are prone to spoilage in high temperature and humidity environments, are inconvenient to store and carry, and have low compliance among people with irregular work schedules such as herding and outdoor labor. Existing pain relief patches have the following drawbacks: The large molecular weight of the drugs makes it difficult to penetrate the thickened stratum corneum barrier in cold regions, resulting in poor transdermal permeability and low bioavailability; traditional processes such as boiling and manual mixing lead to batch-to-batch fluctuations in active ingredient concentrations, making it difficult to guarantee formulation uniformity; flavonoids and volatile oils in the medicinal materials are sensitive to light, heat, and oxygen, and are prone to oxidative degradation or discoloration during room temperature storage, resulting in insufficient physicochemical stability; the adhesive base has poor breathability, easily causing irritation such as stuffiness, allergies, and erythema on dry skin, and is prone to curling and falling off during joint flexion and extension activities, making it unsuitable for herding and sports scenarios. Conventional topical gels lack a temperature-responsive phase change design, are prone to solidification at low temperatures, have poor spreadability, only provide medication through application, lack a closed-loop controlled-release structure, and are prone to drug volatilization and leakage; their formulations are highly versatile and have not been specifically optimized for cold-dampness syndromes or cold skin types, lacking specific adaptability. Therefore, it is necessary to develop a topical gel formulation and synergistic drug delivery system based on ancient prescriptions, which has body temperature-responsive phase change and closed-loop controlled release functions, and is suitable for the skin type and usage scenarios of people in high-altitude and cold regions. Summary of the Invention

[0004] In order to solve the problems of the prior art, the present invention provides a compound gel for treating joint inflammation based on the modification of ancient Chinese medicine prescriptions.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: Firstly, a compound gel for treating joint inflammation based on a modified ancient Chinese medicine formula, comprising the following components by mass percentage: Active ingredient extract 2%~8% Thermosensitive gel matrix 15%~35% Penetration enhancer 1%~5% Moisturizer 5%~15% Add an appropriate amount of pH adjuster to bring the pH to 5.5-6.5. Deionized water balance; The active ingredient extract is composed of the following six medicinal materials' ultrasonic-microwave coupled extracts: 5-10 parts by weight of Terminalia chebula, 5-10 parts by weight of Phyllanthus emblica, 3-8 parts by weight of Lavender, 8-15 parts by weight of wild watermelon, 5-12 parts by weight of Artemisia annua, and 3-8 parts by weight of Chamomile. The thermosensitive gel matrix is ​​a mixture of poloxamer 407 and poloxamer 188, wherein poloxamer 407 accounts for 12% to 25% of the total gel mass and poloxamer 188 accounts for 1% to 6% of the total gel mass.

[0006] In one specific embodiment of the first aspect, the penetration enhancer is selected from one or more of azone, propylene glycol, and menthol; the moisturizer is selected from one or more of glycerin, sorbitol, and sodium hyaluronate.

[0007] In one specific embodiment of the first aspect, the penetration enhancer is a mixture of azone and propylene glycol, wherein azone accounts for 1% to 3% of the total mass of the gel and propylene glycol accounts for 2% to 5% of the total mass of the gel; the moisturizer is glycerin, accounting for 5% to 15% of the total mass of the gel.

[0008] In one specific embodiment of the first aspect, the phase transition temperature of the compound gel is 30~34℃, which enables it to change from a liquid gel phase to a semi-solid gel at body surface temperature, thereby achieving in-situ solidification and stable sustained release for 6~8 hours.

[0009] In one specific embodiment of the first aspect, the process conditions for the ultrasonic-microwave coupled extraction are: extraction temperature of 50~70℃, ultrasonic power of 200~400W, microwave power of 100~300W, and extraction time of 20~60 minutes.

[0010] Secondly, a method for preparing a compound gel includes the following steps: Step 1: Weigh out the following six medicinal herbs according to the specified ratio: Terminalia chebula, Phyllanthus emblica, lavender, wild watermelon, Artemisia annua, and chamomile. Mix them together and then grind them into powder. Step 2: Add the medicinal powder to an ethanol solution with a volume fraction of 50%~80%, with a material-to-liquid ratio of 1:10~1:20 g / mL, and soak for 1~3 hours; Step 3: Use ultrasonic-microwave coupled extraction, with an extraction temperature of 50~70℃, ultrasonic power of 200~400W, microwave power of 100~300W, and extraction time of 20~60 minutes. Filter to obtain the extract. Step 4: Concentrate the extract under reduced pressure to a density of 1.05~1.15 g / mL, dry, and obtain the active ingredient extract powder; Step 5: Under low temperature conditions of 0~8℃, take deionized water, add poloxamer 407 and poloxamer 188, stir until completely dissolved, and obtain a temperature-sensitive gel matrix solution. Step Six: Add humectant and penetration enhancer to the matrix solution obtained in Step Five, and stir until well mixed; Step 7: Dissolve the active ingredient extract powder obtained in Step 4 in deionized water, add it to the mixture obtained in Step 6, and stir until homogeneous; Step 8: Adjust the pH of the system to 5.5-6.5 with a pH adjuster, add deionized water to the total mass, and stir at a low temperature of 0-8℃ until a uniform and transparent gel is formed.

[0011] In one specific embodiment of the second aspect, the gel solution obtained in step eight changes from a liquid phase to a semi-solid gel under conditions ranging from room temperature to body surface temperature.

[0012] Thirdly, a synergistic drug delivery system comprising a compound gel includes: Compound thermosensitive gel; An integrated medication container includes a container body, a medication inlet located on one side of the container body, a replaceable breathable and drug-permeable membrane, a leak-proof sealing structure, and an ergonomic fit surface. The compound gel is contained inside the container body. Bionic protective gear is used to fix the medication container to the joint area.

[0013] In one specific embodiment of the third aspect, the replaceable breathable and drug-permeable membrane is a microporous membrane with a pore size of 0.1~1.0μm; the bionic protective gear is an elastic fabric protective gear with breathable and pressure-fixing functions, and is adapted to the flexion and extension activities of the knee joint, elbow joint, shoulder joint, and ankle joint.

[0014] Fourthly, the application of compound gels or synergistic drug delivery systems in the preparation of drugs for treating osteoarthritis, rheumatoid arthritis, and soft tissue injuries caused by cold-dampness obstruction.

[0015] The beneficial effects of this invention are as follows: 1. Guided by the core principles of the classic Uyghur medical formula, Maijuni Nugal, this invention scientifically modifies and combines six medicinal herbs—Prunus armeniaca, Phyllanthus emblica, lavender, wild watermelon, Artemisia annua, and chamomile—to create a compound formula. These herbs work synergistically to warm the meridians, dispel cold, eliminate dampness, promote blood circulation, reduce inflammation and pain, and moisturize and soothe the skin. Using ultrasound-microwave coupling extraction technology, the cell walls of the herbs are efficiently broken down under mild conditions, promoting the full dissolution of small-molecule flavonoids, tannins, and sesquiterpenes. Combined with low-temperature vacuum concentration and freeze-drying processes, the bioactivity of heat-sensitive components is preserved to the maximum extent. Based on this, the active ingredient extract is uniformly dispersed in a thermosensitive gel matrix composed of poloxamer 407 and poloxamer 188. This matrix is ​​a free-flowing liquid at low temperatures, facilitating infusion and coating. Upon contact with body surface temperature, it rapidly undergoes a sol-gel phase transition, forming a semi-solid gel network. The three-dimensional network structure of the gel can uniformly encapsulate the active ingredients, effectively inhibiting the oxidative degradation of flavonoids and volatile oils, and significantly improving the physicochemical stability and batch-to-batch uniformity of the formulation. On the other hand, combined with the synergistic permeation-enhancing effect of azone and propylene glycol, it reversibly regulates the lipid arrangement of the stratum corneum, reduces the resistance to transdermal drug diffusion, and enables the active ingredients to efficiently penetrate the thickened stratum corneum barrier in cold regions and form a drug reservoir in the epidermis, achieving stable and continuous transdermal release. This overcomes the shortcomings of traditional oral ointments with poor local targeting, ordinary plasters with low transdermal penetration, and conventional gels with no controlled-release capability.

[0016] Secondly, this invention further provides a synergistic drug delivery system composed of a temperature-sensitive gel, an integrated drug delivery chamber, and a biomimetic protective garment. The drug delivery chamber features an injection port, a replaceable breathable and drug-permeable membrane, and a leak-proof sealing structure. Before use, a low-temperature liquid gel is injected into the chamber, and the release rate is precisely controlled through a microporous membrane in a zero-order kinetic mode, preventing leakage and loss of volatile components. The ergonomic fit of the chamber, combined with the pressure-fixing function of the biomimetic elastic protective garment, ensures the drug delivery system fits snugly against frequently flexed and extended areas such as the knees and elbows, preventing slippage and curling even in dynamic scenarios such as herding in cold regions or outdoor work. It also avoids the stuffiness and sensitization caused by ordinary adhesive tape bases on dry and sensitive skin. The gel system itself has high water content and biocompatibility, does not damage the skin barrier, and has shown no adverse reactions after skin irritation and allergy testing, effectively solving the applicability problem of traditional topical preparations to the special skin types in cold regions. This collaborative system combines body temperature-responsive in-situ gelation, closed-loop controlled release, and mechanical fixation, achieving full-chain optimization from drug release and transdermal absorption to secure wearing, significantly improving treatment adherence and clinical efficacy for cold-dampness obstruction type osteoarthritis and soft tissue injuries. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 The image shows a compound gel for treating joint inflammation based on a modified version of a traditional Chinese medicine formula.

[0020] I. Preparation of active ingredient extracts.

[0021] Example 1 (Active ingredient extract A).

[0022] Ingredient ratio: 80g of Terminalia chebula, 80g of Phyllanthus emblica, 50g of lavender, 120g of wild watermelon, 80g of Artemisia annua, and 50g of chamomile.

[0023] Input conditions: Origin of medicinal materials: Terminalia chebula and Phyllanthus emblica are produced in Kashgar, Xinjiang; Lavender is produced in Yili, Xinjiang; Wild watermelon is produced in Turpan, Xinjiang; Artemisia argyi is produced in Altay, Xinjiang; Chamomile is produced in Hotan, Xinjiang.

[0024] Medicinal herb quality requirements: The herbs must meet the relevant provisions of the "Xinjiang Uygur Autonomous Region Uygur Medicinal Herb Standards" after inspection, with a moisture content of ≤12%, a total ash content of ≤8%, and free from mold and insect infestation.

[0025] Preparation steps: Step 1: Take the above six medicinal materials, crush them separately and pass them through a 40-mesh sieve, mix them evenly to obtain medicinal material powder (particle size ≤380μm after sieving).

[0026] Step 2: Add the mixed medicinal powder to a 60% ethanol aqueous solution at a ratio of 1:15 (g / mL), that is, add 15mL of ethanol solution to every 1g of medicinal powder, and soak for 2 hours (room temperature 25℃) to allow the medicinal materials to fully swell.

[0027] Step 3: Use an ultrasonic-microwave coupled extraction device. Set the extraction parameters as follows: extraction temperature 60℃, ultrasonic power 300W (frequency 40kHz), microwave power 200W (frequency 2450MHz), and extraction time 30 minutes. During the extraction process, maintain the temperature inside the extraction tank at 60±2℃ using a circulating water bath, and keep the stirring speed at 100rpm.

[0028] Step 4: After extraction, filter with a 200-mesh filter cloth and collect the filtrate; repeat the extraction of the residue under the same conditions (solid-to-liquid ratio 1:10, extraction for 20 minutes) and combine the two filtrates.

[0029] Step 5: The combined filtrate was concentrated under reduced pressure at 55℃ and a vacuum of -0.08MPa to a relative density of 1.10±0.02 (measured at 60℃) to obtain the concentrate.

[0030] Step 6: Freeze-dry the concentrate: pre-freeze at -40℃ for 2 hours; sublimation drying stage with vacuum <20Pa and temperature -20℃~0℃ for 24 hours; desorption drying stage with temperature 25℃ and vacuum <10Pa for 6 hours. The resulting active ingredient extract powder A has a yield of approximately 22.5% (relative to the total mass of the medicinal materials).

[0031] Output product: Active ingredient extract A, appearing as a light brownish-yellow loose powder with a moisture content ≤5%. HPLC analysis showed that the total flavonoid content (calculated as rutin) was 16.8%, and the total tannin content (calculated as gallic acid) was 11.2%.

[0032] Example 2 (Active Ingredient Extract B) Ingredient ratio: 50g of Terminalia chebula, 50g of Phyllanthus emblica, 30g of lavender, 80g of wild watermelon, 50g of Artemisia annua from Xinjiang, and 30g of chamomile.

[0033] Preparation steps: It was crushed and passed through a 30-mesh sieve.

[0034] Use 50% ethanol by volume, a material-to-liquid ratio of 1:10 (g / mL), and soak for 1 hour.

[0035] Ultrasonic-microwave coupled extraction: temperature 50℃, ultrasonic power 200W, microwave power 100W, extraction time 60 minutes, extraction once.

[0036] After filtration, the sample was concentrated under reduced pressure to a density of 1.05 ± 0.02 (measured at 60℃), and then spray-dried: inlet air temperature 180℃, outlet air temperature 80℃, feed flow rate 50 mL / min. Active ingredient extract B was obtained, with a yield of approximately 20.1%.

[0037] Output: Active ingredient extract B, pale yellow powder, with a total flavonoid content of 14.2% and a total tannin content of 9.5%.

[0038] Example 3 (Active Ingredient Extract C) Ingredient ratio: 100g of Terminalia chebula, 100g of Phyllanthus emblica, 80g of lavender, 150g of wild watermelon, 120g of Artemisia annua, and 80g of chamomile.

[0039] Preparation steps: It was crushed and passed through a 60-mesh sieve.

[0040] Use 80% ethanol by volume, a material-to-liquid ratio of 1:20 (g / mL), and soak for 3 hours.

[0041] Ultrasonic-microwave coupled extraction: temperature 70℃, ultrasonic power 400W, microwave power 300W, extraction time 20 minutes, extraction once.

[0042] The solution was concentrated under reduced pressure to a density of 1.15 ± 0.02 and then freeze-dried (as in Example 1). Active ingredient extract C was obtained, with a yield of approximately 24.3%.

[0043] Output: Active ingredient extract C, dark yellow powder, with a total flavonoid content of 18.3% and a total tannin content of 12.8%.

[0044] II. Preparation of thermosensitive gel, including preferred formulation examples.

[0045] Example 4 (preferred formulation, corresponding to active ingredient extract A).

[0046] Formula composition (total mass 1000g): ; Preparation method (all operations are carried out in an ice-water bath or a cryogenic constant temperature bath at 0~8℃): Step 1: Take approximately 60% of the total volume of deionized water (about 600 mL), place it in a low-temperature environment of 2-6℃, and while stirring, add 200 g of poloxamer 407 and 25 g of poloxamer 188. Stir at 300-500 rpm for 30-60 minutes until completely dissolved into a clear and transparent solution, obtaining the thermosensitive gel matrix solution. Input: Deionized water, P407, P188; Output: Clear matrix solution (low-temperature liquid state).

[0047] Step 2: Add 80g of glycerin, 15g of azone, and 30g of propylene glycol to the above matrix solution in sequence, and continue stirring for 10-15 minutes until homogeneous to obtain mixed solution A. Input: humectant, penetration enhancer; Output: mixed solution A.

[0048] Step 3: Take 50g of active ingredient extract A, add it to a small amount (about 100mL) of deionized water, and dissolve it with ultrasonic assistance (100W power, 25℃ temperature, 5 minutes) to obtain an active ingredient solution. Input: Extract powder, deionized water; Output: Active ingredient solution.

[0049] Step 4: Slowly add the active ingredient solution to mixed solution A while stirring. Control the stirring speed at 300 rpm and the temperature at 2-6℃. Stir for 15 minutes to ensure thorough mixing. Input: Active ingredient solution, mixed solution A; Output: Mixed solution B.

[0050] Step 5: Add triethanolamine dropwise to adjust the pH of mixed solution B to 6.0 ± 0.1 (measured with a precision pH meter). Input: Triethanolamine; Output: Mixed solution with pH 6.0.

[0051] Step 6: Add deionized water to a total mass of 1000g, and continue stirring at 2~6℃ for 30 minutes until a homogeneous, transparent, and bubble-free gel solution is formed. Output: Finished temperature-sensitive gel solution.

[0052] Product characteristics: Appearance: Pale yellow transparent viscous liquid (below 25℃), no visible particles.

[0053] pH value: 6.0±0.1.

[0054] Phase transition temperature determination: The test tube inversion method was used. The gel solution was placed in a test tube, and the temperature was slowly increased in a water bath. The phase transition temperature was defined as the temperature at which the gel stopped flowing within 30 seconds of the test tube being inverted. The measured phase transition temperature was 32±1℃.

[0055] Gel strength: The hardness (maximum compressive force) measured by a texture analyzer at 37℃ is 0.28±0.03N.

[0056] Viscosity (25℃, Brookfield DV2T, rotor S64, speed 20rpm): 1800±200 mPa·s.

[0057] Example 5, low concentration formulation.

[0058] Formula composition (total mass 1000g): Active ingredient extract B 20g, P407 150g, P188 15g, azone 10g, propylene glycol 20g, glycerin 50g, deionized water to make up, pH 6.0.

[0059] Preparation method: Same as in Example 4.

[0060] Product characteristics: Phase change temperature 33±1℃; viscosity (25℃) 1200±150 mPa·s.

[0061] Example 6, high-concentration formulation.

[0062] Formula composition (total mass 1000g): Active ingredient extract C 80g, P407 250g, P188 60g, azone 30g, propylene glycol 50g, glycerin 150g, deionized water to make up, pH 6.0.

[0063] Preparation method: Same as in Example 4 (note that the solvent volume should be increased appropriately when dissolving the active ingredient).

[0064] Product characteristics: Phase change temperature 30±1℃; viscosity (25℃) 2800±250 mPa·s.

[0065] III. Quality control methods, HPLC fingerprint chromatogram.

[0066] To ensure the batch-to-batch quality stability and component uniformity of the compound gels prepared in Examples 4-6, an HPLC fingerprint control standard was established.

[0067] 3.1 Preparation of the test solution.

[0068] Accurately weigh 1.0 g of the gel from Example 4, place it in a 10 mL volumetric flask, add methanol-water (1:1) and sonicate to dissolve and dilute to volume. Filter through a 0.45 μm microporous membrane and collect the filtrate. Prepare the test solutions for Examples 5 and 6 using the same method.

[0069] 3.2 Preparation of reference solution.

[0070] Accurately weigh appropriate amounts of rutin reference standard, gallic acid reference standard, and artemisinin reference standard, and add methanol to prepare mixed reference standard solutions containing 0.2 mg, 0.1 mg, and 0.1 mg per 1 mL, respectively.

[0071] 3.3 Chromatographic conditions.

[0072] Column: Agilent HC-C18 (4.6 mm × 250 mm, 5 μm); Mobile phase: acetonitrile (A) — 0.2% phosphoric acid aqueous solution (B), gradient elution program as follows: ; Detection wavelengths: 0~35min 280nm (flavonoids), 35~50min 272nm (tannins), 50~60min 210nm (volatile oils and sesquiterpenes); Flow rate: 1.0 mL / min; Column temperature: 30℃; Injection volume: 10 μL.

[0073] 3.4 Fingerprint pattern determination and similarity evaluation.

[0074] Ten batches of samples prepared continuously in Example 4 were analyzed and chromatograms were recorded under the conditions described above. The relative retention time and relative peak area were calculated using the rutin reference peak (retention time approximately 22.5 min). A total of 13 common fingerprint peaks were identified. Similarity was calculated using the "Similarity Evaluation System for Chromatographic Fingerprints of Traditional Chinese Medicine" (2012 version). The similarity between the fingerprint chromatograms of all 10 batches of samples and the reference fingerprint chromatogram was greater than 0.95. Output: Fingerprint chromatogram quality standard.

[0075] 3.5 Content determination (total flavonoids, total tannins).

[0076] Using ultraviolet spectrophotometry: For total flavonoids, rutin was used as the reference, and the NaNO2 - Al(NO3)3 color development method was used for determination at 510 nm; for total tannins, gallic acid was used as the reference, and the phosphomolybdic tungstic acid color development method was used for determination at 760 nm. The determination results of three batches of samples in Example 4 were: total flavonoids (calculated as rutin) 0.82% - 0.88% (that is, every 100 g of gel contains 5 g of active ingredient extract, equivalent to 16.8% of flavonoid content in the extract, and the total flavonoids in the gel are about 0.84%), RSD ≤ 2.5%; total tannins (calculated as gallic acid) 0.55% - 0.59%, RSD ≤ 2.8%. It meets the internal control standards (total flavonoids ≥ 0.75%, total tannins ≥ 0.50%).

[0077] IV. In vitro percutaneous absorption experiment, Franz diffusion cell method.

[0078] 4.1 Experimental materials. Test samples: gels of Example 4, Example 5, and Example 6; reference substance: a commercially available diclofenac diethylamine emulsion of a certain brand (positive control); blank gel matrix (without active ingredients).

[0079] Experimental animals: SD rats, male, weighing 200 - 220 g, purchased from the Experimental Animal Center of Xinjiang Medical University (license number: SYXK(Xin)2020 - 0003), and raised in a SPF - level environment.

[0080] Main instruments: Improved Franz diffusion cell (effective diffusion area 1.77 cm 2 , receiving pool volume 12 mL); HPLC instrument (Agilent 1260).

[0081] 4.2 Preparation of excised skin. The rats were sacrificed, the abdominal hair was removed with an electric hair clipper, the abdominal skin was dissected, subcutaneous fat and adherent tissues were removed, and it was rinsed thoroughly with normal saline. The integrity of the skin was checked (no damage), and it was stored at -20 °C and used within 1 week. It was thawed naturally at room temperature before use.

[0082] 4.3 Percutaneous absorption experiment operation. The thawed rat skin was fixed between the supply pool and the receiving pool of the Franz diffusion cell, with the stratum corneum facing the supply pool. pH 7.4 phosphate buffer solution (containing 20% ethanol to maintain the sink condition) was added to the receiving pool, air bubbles were exhausted, the magnetic stirring rotor speed was 300 rpm, and the water bath circulation was maintained at 37 ± 0.5 °C. After pre - equilibration for 30 min, 1.0 g of gels of Example 4, 5, 6 and the positive control were respectively added to the supply pool (uniformly coated on the skin surface), and 1.0 g of the gel matrix was coated in the blank control group. Each group had 3 parallel diffusion cells.

[0083] Samples of 1.0 mL were taken from the receiving cell at 1, 2, 4, 6, 8, 12, and 24 hours (with simultaneous replenishment of isothermal and equal-volume fresh receiving solution). After passing through a 0.45 μm filter membrane, the content of active ingredients (calculated as the sum of rutin, gallic acid, and artemisinin) was determined by HPLC. The cumulative permeate flow rate Q (μg / cm³) was calculated. 2 ) and transdermal permeability J (μg·cm -2 ·h -1 ).

[0084] 4.4 Experimental Results.

[0085] ; Transdermal transdermal rate J (linear regression from 0 to 12 h): Example 4: 29.8 μg·cm -2 ·h -1 (R) 2 =0.996) Example 5: 19.6 μg·cm -2 ·h -1 (R) 2 =0.991) Example 6: 33.5 μg·cm -2 ·h -1 (R) 2 =0.998) Positive control: 14.8 μg·cm -2 ·h -1 (R) 2 =0.989) Conclusion: The transdermal permeation rates of Examples 4-6 of this invention were significantly higher than those of the positive control (P<0.01). The cumulative permeation amount of Example 4 over 24 hours was 2.07 times that of the positive control, indicating that the thermosensitive gel significantly improved the transdermal absorption of the drug.

[0086] 4.5 Determination of skin retention. After the transdermal test, the skin was removed, the surface residual gel was washed off with physiological saline, the skin was cut into small pieces, and methanol was added for ultrasonic extraction for 30 min. The supernatant was collected by centrifugation, and the content of active ingredients in the skin tissue was determined by HPLC. The skin retention in Group 4 of Example 4 was 42.5 ± 5.2 μg / cm³. 2 The positive control group had a concentration of 18.3 ± 3.1 μg / cm³. 2 The drug concentration in Example 4 was 2.32 times that of the positive control group. This indicates that the gel of the present invention can form drug reservoirs in the stratum corneum and epidermis, which is beneficial for sustained release.

[0087] V. Evaluation of anti-inflammatory activity of cells (LPS-induced RAW264.7 macrophage model).

[0088] 5.1 Experimental Materials. Cell line: RAW264.7 mouse macrophages (purchased from the Cell Bank of the Chinese Academy of Sciences Type Culture Collection Committee).

[0089] Test samples: Gel from Example 4, diluted to different concentrations (12.5, 25, 50, 100, 200 μg / mL, based on extract) with DMEM high-glucose medium. Blank control: DMEM medium; Model control: LPS (1 μg / mL); Positive control: Dexamethasone (1 μM).

[0090] Detection indicators: NO content (Griess method), TNF-α and IL-1β (ELISA kit), cell viability (CCK-8 method).

[0091] 5.2 Experimental Methods. Logarithmically growing RAW264.7 cells were selected and their density adjusted to 5 × 10⁻⁶ cells / year. 4 Cells were seeded at a concentration of 100 μL / mL in 96-well plates and cultured for 24 h (37℃, 5% CO2). The supernatant was discarded, and culture medium containing different concentrations of the test sample was added, with three replicates per group. After 2 h of pretreatment, except for the blank control group, LPS was added to each well to a final concentration of 1 μg / mL, and cultured for another 24 h. The supernatant was collected, and the levels of NO, TNF-α, and IL-1β were determined according to the kit instructions. A blank control group without LPS and a model group with only LPS were also included. Cell viability was measured using the CCK-8 assay: parallel plates were used, and after treatment, 10 μL of CCK-8 solution was added to each well, incubated for 2 h, and the OD value was measured at 450 nm.

[0092] 5.3 Experimental Results.

[0093] ; Note: *P<0.05 compared with the model control group.

[0094] Conclusion: The gel extract of this invention inhibited LPS-induced release of NO, TNF-α, and IL-1β in a dose-dependent manner within the range of 12.5–100 μg / mL, with an IC50 concentration of [missing value]. 50 The concentration was approximately 42 μg / mL (as NO). At 100 μg / mL, the inhibition rate reached 79.4%, comparable to the dexamethasone group. All concentrations (≤100 μg / mL) had no significant effect on cell viability (>90%), while at 200 μg / mL, cell viability decreased slightly but remained above 85%, indicating a wide safety window.

[0095] VI. Animal in vivo anti-inflammatory pharmacodynamic experiments.

[0096] 6.1 Xylene-induced ear swelling experiment in mice.

[0097] Experimental animals: Kunming mice, male, weighing 20-25g, 50 mice, were randomly divided into 5 groups (n=10): model control group (physiological saline), positive control group (diclofenac diethylamine emulsion, commercially available), Example 4 group, Example 5 group, and Example 6 group.

[0098] Experimental Procedure: Mice in each group had 0.05 g of the corresponding drug evenly applied to both the anterior and posterior surfaces of their right ear. The left ear was left untreated as a self-control. Thirty minutes after drug administration, 0.05 mL of xylene was applied to both sides of the right ear of each group to induce inflammation. One hour after inflammation induction, mice were euthanized by cervical dislocation. Both ears were cut off along the auricular baseline, and ear pieces were accurately weighed from the same location using an 8 mm diameter punch. The degree of swelling (right ear weight - left ear weight) and inhibition rate were calculated: Inhibition rate (%) = (average swelling of the model group - average swelling of the drug-treated group) / average swelling of the model group × 100%.

[0099] Experimental results: ; Compared with the model control group, *P<0.01.

[0100] Conclusion: The inhibition rates of xylene-induced ear swelling in mice in Examples 4 and 6 were 64.8% and 67.2%, respectively, which were not statistically different from the positive control (68.0%) (P>0.05). The inhibition rate of Example 5 was 51.6%, which was still significantly higher than that of the model group (P<0.01).

[0101] 6.2 Carrageenan-induced rat paw edema experiment.

[0102] Experimental animals: 50 male SD rats, weighing 180-220g, were randomly divided into 5 groups (n=10), with the grouping method as described in 6.1.

[0103] Experimental procedure: For each group of rats, with the right hind paw facing upwards, 0.3 g / paw of the corresponding drug was evenly applied to the plantar area 30 min before inflammation induction. Then, 0.1 mL of 1% carrageenan was subcutaneously injected into the right hind paw to induce inflammation. The plantar circumference was measured before inflammation and at 0.5, 1, 2, 4, 6, 8, and 12 h after inflammation induction using a plantar circumference measuring instrument. The swelling degree (post-inflammatory circumference - pre-inflammatory circumference) and swelling inhibition rate (%) were calculated as follows: (average swelling degree of the model group - average swelling degree of the drug-treated group) / average swelling degree of the model group × 100%.

[0104] Experimental results (swelling degree, mm, x̄±SD): ; Compared with the model control group, *P<0.05.

[0105] Inhibition rate (at 4h): positive control 56.4%, Example 4 group 55.3%, Example 5 group 43.4%, Example 6 group 57.9%.

[0106] Conclusion: The gel of the present invention significantly inhibited carrageenan-induced rat paw edema within 2-8 hours after inflammation (P<0.05). The effects of Examples 4 and 6 were comparable to the positive control and lasted for 12 hours, showing good long-lasting anti-inflammatory effects.

[0107] 6.3 Acetic acid-induced writhing response test in mice (analgesia test).

[0108] Experimental animals: Kunming mice, male, weighing 20-25g, 50 mice, randomly divided into 5 groups (n=10): model control group (physiological saline), positive control group (diclofenac diethylamine emulsion), Example 4 group, Example 5 group, and Example 6 group.

[0109] Experimental procedure: Mice in each group were given 0.1g of the corresponding drug applied to their abdomen. 30 minutes after administration, each mouse was injected intraperitoneally with 0.2mL of 0.6% acetic acid solution. The number of writhing responses observed in the mice within 15 minutes of injection was immediately observed and recorded (one writhing response was defined as abdominal concavity, hind limb extension, and hip elevation). The writhing inhibition rate (%) was calculated as: (Average number of writhing responses in the model group - Average number of writhing responses in the drug-treated group) / Average number of writhing responses in the model group × 100%.

[0110] Experimental results: ; Compared with the model control group, *P<0.01.

[0111] Conclusion: The inhibition rates of the writhing response to acetic acid-induced visceral pain in Examples 4 and 6 were 59.6% and 62.1%, respectively, indicating that the gel of the present invention has a significant analgesic effect.

[0112] VII. Skin Safety Evaluation 7.1 Acute skin irritation test Laboratory animals: New Zealand rabbits, standard grade, weighing 2.0~2.5kg, half male and half female, 6 rabbits in total. Hair was removed from both sides of the spine on the back 24 hours before the experiment, covering an area of ​​approximately 3cm × 3cm, and the skin was examined and found to be undamaged.

[0113] Experimental Methods: Self-control was used, applying 0.5g of the gel from Example 4 to the dehaired area on the left side, and an equal amount of blank gel matrix (without active ingredients) to the right side as a negative control. The area was covered with non-irritating medical gauze and then secured with non-irritating tape. Each animal was housed separately. The drug was administered once daily for 7 consecutive days. Before each administration, the erythema and edema at the administration site were observed and recorded, and scored according to the skin irritation response scoring criteria in the "Cosmetic Safety Technical Specifications" (2015 edition). A second observation was conducted 72 hours after the last administration. The average score for each animal was calculated daily, and the animals were graded according to the intensity of irritation.

[0114] Scoring criteria: Erythema: No erythema 0 points, mild erythema (barely visible) 1 point, moderate erythema (clearly visible) 2 points, severe erythema (purplish-red) 3 points, severe erythema (mild eschar) 4 points; Edema: No edema 0 points, mild edema (barely visible) 1 point, moderate edema (obviously raised) 2 points, severe edema (skin raised about 1mm) 3 points, severe edema (skin raised >1mm) 4 points.

[0115] Experimental Results: After 7 days of continuous administration and 72 hours after the last administration, no irritant reactions such as erythema or edema were observed in either the Example 4 group or the blank matrix group; the irritation response score was 0. Pathological Histological Examination: Skin samples were taken from the administration site, stained with hematoxylin and eosin (HE), and observed under a light microscope. The stratum corneum of the skin in the Example 4 group was intact, with no thickening or thinning of the epidermis and no inflammatory cell infiltration in the dermis, showing no difference from the blank matrix group and normal skin.

[0116] Conclusion: The compound gel of this invention is non-irritating to rabbit skin.

[0117] 7.2 Skin allergy test Experimental animals: White guinea pigs, standard grade, weighing 300-400g, half male and half female, 30 animals in total. Hair was removed from the left side of the back, approximately 3cm x 3cm, 24 hours before the experiment.

[0118] Experimental methods: The Buehler test (closed patch test) was used. Participants were randomly divided into three groups (n=10): negative control group (blank gel matrix), positive control group (1% 2,4-dinitrochlorobenzene, DNCB), and Example 4 group.

[0119] Induction phase: On days 0, 7, and 14, 0.2g of the corresponding sample was applied to the hairless area of ​​each group of animals, covered with two layers of gauze, and sealed and fixed with non-irritating adhesive tape for 6 hours. The same procedure was performed on days 7 and 14 after hairless treatment at the same location (right side of the back).

[0120] Challenge phase: 14 days after the last induction (day 28), hair was removed from the untreated area on the animal's back, and 0.2g of the corresponding sample was applied and sealed for 6 hours. Skin reactions were observed 24 hours and 48 hours after removal of the test substance, and the sensitization rate was recorded according to the skin sensitization reaction scoring standard of the "Cosmetic Safety Technical Specifications".

[0121] Sensitization rate assessment: 0-8% is weak sensitization, 9-28% is mild sensitization, 29-64% is moderate sensitization, 65-80% is high sensitization, and 81-100% is extreme sensitization.

[0122] Experimental results: ; No allergic reactions such as erythema or edema were observed in the Example 4 group and the negative control group at 24h and 48h after stimulation, while obvious erythema and edema were observed in the positive control group.

[0123] Conclusion: The compound gel of this invention has no sensitizing effect on guinea pig skin.

[0124] VIII. Stability Test 8.1 Accelerated Testing The gel from Example 4 (filled into an integrated medication container and sealed) was placed under accelerated testing conditions (temperature 40℃±2℃, relative humidity 75%±5%) for 6 months. Samples were taken at 0, 1, 2, 3, and 6 months to test appearance, pH value, phase transition temperature, gel viscosity, content of active ingredients (total flavonoids, total tannins) and microbial limits.

[0125] result: ; Conclusion: After 6 months of accelerated testing, all indicators remained within acceptable ranges (total flavonoids decreased by 4.0%, and total tannins decreased by 6.5%). Microbial limits met the requirements of the 2020 edition of the Chinese Pharmacopoeia, Part IV (aerobic bacteria count ≤10). 2 cfu / g, mold and yeast count ≤10 1 (The cfu / g concentration should be within acceptable limits, and Staphylococcus aureus and Pseudomonas aeruginosa should not be detected.) This indicates that the gel of this invention has good stability.

[0126] 8.2 Long-term test The gel from Example 4 was placed under long-term test conditions (temperature 25℃±2℃, relative humidity 60%±5%) for 12 months, with samples taken and tested every 3 months. The results showed that all indicators met the internal control standards. The predicted shelf life is up to 24 months.

[0127] IX. Comparative Trial (Comparison with Traditional Formulations) 9.1 Comparison Group Settings Control Group 1 (Traditional Oral Honey Paste): Prepare Majoon Nujul according to the method recorded in the ancient medical book "Badiyi Medicine Book". Take equal parts of Terminalia chebula Retz., Phyllanthus emblica L. (nucleus removed and milk-bubbled), Lavandula angustifolia Mill., Polypodiodes niponica (Mett.) Ching, and Cuscuta chinensis Lam., crush them, and make pills with honey, each pill weighing about 10 g. Dissolve it in warm water and take orally before use.

[0128] Control Group 2 (Ordinary Adhesive Plaster): A commercially available joint pain relief plaster of a certain brand (the main ingredients are capsicum tincture, belladonna tincture, menthol oil, methyl salicylate, etc.), and the matrix is rubber, zinc oxide, rosin, vaseline, etc.

[0129] Control Group 3 (Conventional Gel): Use a common carbomer matrix (without thermosensitive components), the active ingredient extract is the same as in Example 4, without adding poloxamer, and prepare a common gel.

[0130] Group of the Invention: The thermosensitive gel of Example 4 + drug reservoir + bionic protective device synergistic drug delivery system.

[0131] 9.2 In Vitro Transdermal Comparison Perform Franz diffusion cell transdermal experiments in the same method (n = 3), and measure the 24-hour cumulative permeation amount.

[0132] ; Compared with the conventional gel, *P < 0.01.

[0133] Conclusion: The transdermal absorption amount of the gel of the present invention is 2.55 times that of the conventional gel and 7.56 times that of the ordinary adhesive plaster, with significant advantages.

[0134] 9.3 Pharmacodynamic Comparison (Rat Plantar Swelling Model, 4-hour Inhibition Rate) ; Compared with the conventional gel, *P < 0.05.

[0135] Conclusion: The anti-inflammatory effect of the group of the present invention is significantly better than that of the oral honey paste and the ordinary adhesive plaster (P < 0.01), and also better than that of the conventional gel (P < 0.05). The oral honey paste has a slow onset of action, and the systemic distribution leads to a low local concentration; the ordinary adhesive plaster has poor transdermal penetration; the conventional gel has no body temperature phase change and airtight controlled release, and the drug efficacy is easily lost; the present invention realizes efficient transdermal and sustained release through thermosensitive phase change + airtight chamber + protective device.

[0136] 9.4 Skin Adaptability and User Evaluation Recruit 30 patients with knee osteoarthritis of cold-dampness obstruction type (aged 45 - 65 years, disease course ≥ 1 year) in Altay Region, Xinjiang, and randomly divide them into 3 groups (n = 10): ordinary adhesive plaster group, conventional gel group, and group of the present invention. Continuously use for 7 days, and evaluate skin irritation and use convenience.

[0137] Skin irritation (number of cases with erythema / itching): In the ordinary adhesive plaster group, 5 cases (50%) experienced local redness and itching, and 2 of them were forced to discontinue the medication.

[0138] In the standard gel group: 2 cases (20%) had mild itching without erythema.

[0139] In this invention group: 0 cases (0%) of discomfort.

[0140] Ease of use rating (out of 10, higher is better): Regular adhesive bandage: 6.2±1.5 (easily curls at the edges, falls off, and is inconvenient during exercise) Regular gel group: 7.5±1.2 (requires application, easily rubbed off by clothing) The invention group: 9.1±0.8 (the protective gear is fixed and will not fall off, allowing for normal grazing and work). Conclusion: This invention has significant advantages in terms of skin safety and ease of use in cold regions.

[0141] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A compound gel for treating joint inflammation based on a modified ancient Chinese medicine formula, characterized in that, It consists of the following components by mass percentage: Active ingredient extract 2%~8% Thermosensitive gel matrix 15%~35% Penetration enhancer 1%~5% Moisturizer 5%~15% Add an appropriate amount of pH adjuster to bring the pH to 5.5-6.

5. Deionized water balance; The active ingredient extract is composed of the following six medicinal materials' ultrasonic-microwave coupled extracts: 5-10 parts by weight of Terminalia chebula, 5-10 parts by weight of Phyllanthus emblica, 3-8 parts by weight of Lavender, 8-15 parts by weight of wild watermelon, 5-12 parts by weight of Artemisia annua, and 3-8 parts by weight of Chamomile. The thermosensitive gel matrix is ​​a mixture of poloxamer 407 and poloxamer 188, wherein poloxamer 407 accounts for 12% to 25% of the total gel mass and poloxamer 188 accounts for 1% to 6% of the total gel mass.

2. The compound gel according to claim 1, characterized in that, The penetration enhancer is selected from one or more of azone, propylene glycol, and menthol; the moisturizer is selected from one or more of glycerin, sorbitol, and sodium hyaluronate.

3. The compound gel according to claim 2, characterized in that, The penetration enhancer is a mixture of azone and propylene glycol, wherein azone accounts for 1% to 3% of the total mass of the gel and propylene glycol accounts for 2% to 5% of the total mass of the gel; the moisturizer is glycerin, accounting for 5% to 15% of the total mass of the gel.

4. The compound gel according to claim 1, characterized in that, The phase transition temperature of the compound gel is 30~34℃, which can change from a liquid gel to a semi-solid gel at body surface temperature, achieving in-situ solidification and stable slow release for 6~8 hours.

5. The compound gel according to claim 1, characterized in that, The process conditions for ultrasonic-microwave coupled extraction are as follows: extraction temperature is 50~70℃, ultrasonic power is 200~400W, microwave power is 100~300W, and extraction time is 20~60 minutes.

6. A method for preparing the compound gel according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Weigh out the following six medicinal herbs according to the specified ratio: Terminalia chebula, Phyllanthus emblica, lavender, wild watermelon, Artemisia annua, and chamomile. Mix them together and then grind them into powder. Step 2: Add the medicinal powder to an ethanol solution with a volume fraction of 50%~80%, with a material-to-liquid ratio of 1:10~1:20 g / mL, and soak for 1~3 hours; Step 3: Use ultrasonic-microwave coupled extraction, with an extraction temperature of 50~70℃, ultrasonic power of 200~400W, microwave power of 100~300W, and extraction time of 20~60 minutes. Filter to obtain the extract. Step 4: Concentrate the extract under reduced pressure to a density of 1.05~1.15 g / mL, dry, and obtain the active ingredient extract powder; Step 5: Under low temperature conditions of 0~8℃, take deionized water, add poloxamer 407 and poloxamer 188, stir until completely dissolved, and obtain a temperature-sensitive gel matrix solution. Step Six: Add humectant and penetration enhancer to the matrix solution obtained in Step Five, and stir until well mixed; Step 7: Dissolve the active ingredient extract powder obtained in Step 4 in deionized water, add it to the mixture obtained in Step 6, and stir until homogeneous; Step 8: Adjust the pH of the system to 5.5-6.5 with a pH adjuster, add deionized water to the total mass, and stir at a low temperature of 0-8℃ until a uniform and transparent gel is formed.

7. The preparation method according to claim 6, characterized in that, The gel solution obtained in step eight changes from a liquid phase to a semi-solid gel under conditions ranging from room temperature to body surface temperature.

8. A synergistic drug delivery system comprising the compound gel according to any one of claims 1 to 5, characterized in that, include: Compound thermosensitive gel; An integrated medication container includes a container body, a medication inlet located on one side of the container body, a replaceable breathable and drug-permeable membrane, a leak-proof sealing structure, and an ergonomic fit surface. The compound gel is contained inside the container body. Bionic protective gear is used to fix the medication container to the joint area.

9. The synergistic drug delivery system according to claim 8, characterized in that, The replaceable breathable and drug-permeable membrane is a microporous membrane with a pore size of 0.1~1.0μm; the bionic protective gear is an elastic fabric protective gear with breathable and pressure-fixing functions, and is adapted to the flexion and extension activities of the knee, elbow, shoulder and ankle joints.

10. The use of the compound gel according to any one of claims 1 to 5 or the synergistic drug delivery system according to any one of claims 8 to 9 in the preparation of a medicament for treating osteoarthritis of the cold-dampness obstruction type, rheumatoid arthritis and soft tissue injury.

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