Traditional Chinese medicine for treating diabetic neuropathy and preparation method thereof

Abstract

This application relates to the field of traditional Chinese medicine pharmaceutical technology, and discloses a traditional Chinese medicine for treating diabetic neuropathy and its preparation method. The traditional Chinese medicine is prepared from Coptis chinensis, Corydalis yanhusuo, Schisandra chinensis, Cornus officinalis, Astragalus membranaceus, and Cinnamomum cassia. The preparation method includes: low-temperature differential pretreatment of the raw materials; gas-phase assisted mechanical activation of components A and C under pressurized carbon dioxide environment, utilizing in-situ generation of carbamate intermediates in the gas phase to reduce lattice energy; subsequently, component B is added and pulsed milling is performed, directionally assembling into a hydrophobic ion-pair complex through a thermodynamically driven ligand substitution reaction; finally, the pressure and temperature are increased in situ to convert the reaction medium into a supercritical fluid for integrated extraction. This invention achieves the transformation of the active ingredient from a hydrophilic to a lipophilic chemical form through a gas-phase activation and stepwise substitution strategy, enabling it to effectively penetrate the blood-nerve barrier. Simultaneously, the low-temperature, anaerobic environment throughout the process effectively avoids the degradation of heat-sensitive components.

Description

Technical Field

[0001] This invention relates to the field of traditional Chinese medicine pharmaceutical technology, specifically to a traditional Chinese medicine for treating diabetic neuropathy and its preparation method. Background Technology

[0002] Diabetic neuropathy (DPN) is one of the most common chronic complications of diabetes mellitus, characterized primarily by demyelination of nerve fibers, axonal atrophy, and thickening of the microvascular basement membrane. In clinical treatment, effective drug delivery faces a significant anatomical barrier: the blood-nerve barrier. The chronic hyperglycemia in diabetic patients leads to tight junctions of microvascular endothelial cells and thickened glycosylation of the basement membrane, making it extremely difficult for conventional drug molecules to penetrate this barrier and reach the neuronal space to exert their repair effects. Therefore, developing a drug delivery system capable of efficiently penetrating the blood-nerve barrier is crucial for treating DPN.

[0003] Traditional Chinese medicine (TCM) has accumulated rich experience in treating diabetes and its complications. Commonly used herbs such as Coptis chinensis, Corydalis yanhusuo, and Schisandra chinensis contain abundant berberine, corydaline, and lignans, exhibiting significant anti-inflammatory, antioxidant, and neurotrophic activities. However, existing TCM preparations generally suffer from low bioavailability and poor targeting. The fundamental reason is that the alkaloid active components in herbs like Coptis chinensis exist naturally primarily in the form of hydrochloride or sulfate. These salt compounds are highly polar and water-soluble, but have very low lipid solubility. According to the physicochemical principles of biomembrane transport, highly polar molecules are repelled by the lipid-rich myelin sheath and blood-nerve barrier, making it difficult for them to enter nerve tissue via passive diffusion. Traditional decoction or ethanol reflux extraction processes merely transfer these polar components from the plant matrix to the solvent without altering their chemical form. Therefore, the resulting drugs struggle to overcome physiological barriers, limiting their clinical efficacy.

[0004] To improve the lipid solubility of traditional Chinese medicine (TCM) components, existing medicinal chemical modification techniques attempt to shield molecular polarity by forming ion-pair complexes. However, current preparation methods mainly rely on liquid-phase reaction systems, requiring large amounts of organic solvents as reaction media. This not only makes subsequent solvent removal processes cumbersome and poses a risk of residue, but the solvation effect in the liquid phase often hinders the tight binding of ion pairs, leading to poor product stability. Furthermore, TCM compound formulas contain heat-sensitive glycosides such as astragaloside A, which are highly susceptible to hydrolysis or oxidative degradation during traditional long-term hot solvent extraction or drying processes, resulting in the loss of active ingredients and reduced efficacy.

[0005] The emerging field of mechanochemistry in recent years has provided new ideas for solvent-free preparation, but challenges remain when dealing with complex solid-phase systems such as natural medicinal materials. Due to the dense encapsulation of plant cell walls and the high lattice energy between active ingredient molecules, simple solid-phase mechanical grinding often fails to break the molecular lattice bonds, resulting in reactions that only occur on the particle surface, with internal components not being fully exposed and transformed, leading to low reaction conversion rates. Although some studies have attempted to introduce small amounts of liquid to assist grinding, this reintroduces the problems of solvent residue and degradation of heat-sensitive components. How to simultaneously achieve plant cell wall disruption, chemical structure modification of active ingredients, and protection of heat-sensitive components in a solvent-free, low-temperature system that can effectively overcome the high energy barrier of solid-phase reactions is a pressing technical challenge in the field of modern Chinese medicine preparation technology. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a traditional Chinese medicine for treating diabetic neuropathy and its preparation method, which solves the problems of existing traditional Chinese medicines for treating diabetic neuropathy, such as the difficulty in penetrating the blood-nerve barrier due to the high polarity of active ingredients, the incomplete transformation caused by the difficulty in overcoming the lattice energy barrier in traditional solid-phase reactions, and the easy degradation of heat-sensitive components during the preparation process.

[0007] To achieve the above objectives, the first aspect of the present invention provides a traditional Chinese medicine for treating diabetic neuropathy.

[0008] This traditional Chinese medicine is prepared from the following raw materials in parts by weight: Component A includes 20-40 parts of Coptis chinensis and 15-30 parts of Corydalis yanhusuo; Component B includes 20-35 parts of Schisandra chinensis, 15-25 parts of Cornus officinalis, and 15-30 parts of Astragalus membranaceus; Component C includes 5-15 parts of Cinnamomum cassia. The medicine is a reddish-brown to dark brown oily or semi-solid paste. It is prepared using a solvent-free gas-phase assisted solid-phase reaction and supercritical fluid phase transformation extraction process.

[0009] Among them, the alkaloids in component A and the organic acids in component B exist in the form of ion-pair complexes, and component C is distributed around the complexes as an osmotic medium.

[0010] The second aspect of this invention provides a method for preparing the above-mentioned traditional Chinese medicine for treating diabetic neuropathy.

[0011] The method includes the following steps: S1. Low-temperature differentiated pretreatment: Components A, B, and C are subjected to low-temperature pulverization pretreatment respectively. Component A is pulverized at -25℃ to -15℃, with the moisture content controlled to be less than 2.0wt%; Components B and C are mixed and pulverized at -10℃ to 0℃, with the moisture content controlled to be 3.0-5.0wt%.

[0012] S2. Gas-phase assisted mechanical activation: Pretreated component A and component C are added to a high-pressure planetary ball mill jar in a specific ratio, sealed, and filled with carbon dioxide gas. The jar is pressurized, with the pressure controlled at 0.8-1.5 MPa. Ball milling activation is performed under pressurized conditions, with a ball-to-material mass ratio of 15:1 to 25:1, a ball mill speed of 300-450 rpm, a grinding time of 15-30 minutes, and the temperature inside the ball mill jar controlled below 35℃. During this process, carbon dioxide is in a subcritical pressurized gaseous state, and the alkaloids in component A react with carbon dioxide in situ under mechanical energy to form carbamate intermediates, thus lowering the lattice energy.

[0013] S3. In-situ Stereoselective Assembly: Add pretreated component B to the ball mill jar from step S2, replenish with carbon dioxide gas, and adjust the pressure inside the jar to 1.5-2.0 MPa. Continue the ball milling reaction using a pulse grinding mode, setting the speed to 500-650 rpm, cycling forward for 3 minutes, stopping for 1 minute, and then reversing for 3 minutes, for a total grinding time of 45-90 minutes. In this step, the organic acid in component B undergoes a ligand displacement reaction with the intermediate generated in step S2, displacing carbon dioxide and forming a hydrophobic ion-pair complex, until the material presents an oily, semi-solid state.

[0014] S4. Phase Transformation and Integrated Extraction: Increase the pressure inside the ball mill jar to 25-35 MPa and the temperature to 40-55 °C, converting the carbon dioxide inside the jar into a supercritical fluid state. Maintain these supercritical conditions and circulate the extraction at a flow rate of 20-40 L / h for 60-120 minutes. At this time, the generated ion-pair complex dissolves in the supercritical carbon dioxide. Subsequently, the fluid is introduced into a desorption vessel, and the pressure is reduced to 4-6 MPa and the temperature to 30-40 °C for desorption separation to obtain the extract.

[0015] S5. Formulation: Collect the extract after separation in step S4, and degas it under vacuum at 30-40℃ to remove residual carbon dioxide, thereby obtaining the traditional Chinese medicine.

[0016] This invention provides a traditional Chinese medicine for treating diabetic neuropathy and its preparation method. It has the following beneficial effects: 1. This invention significantly reduces the solid-phase reaction energy barrier by employing a gas-phase assisted mechanical activation mechanism. Carbon dioxide is introduced as a gas-phase activation medium during the mechanochemical reaction process. The chemical activity of gas molecules under mechanical energy excitation forms a temporary, highly active carbamate intermediate with the alkaloid donor. This intervention of gas-phase molecules acts as a molecular wedge, effectively reducing the high lattice energy of the solid raw materials and increasing the exposure of reactive sites. This overcomes the common problems of insufficient interfacial contact and reaction inertia in traditional solid-phase grinding reactions, thereby promoting the deep transformation and binding between drug components.

[0017] 2. This invention achieves the directional assembly of supramolecular structures through a ligand substitution strategy based on thermodynamic differences. By employing a specific stepwise process, it utilizes the thermodynamic property that the binding energy between organic acid acceptors and alkaloids is greater than that between carbon dioxide and alkaloids to drive the precise substitution of carbon dioxide molecules, which serve as temporary protective groups, by macromolecular organic acids. This chemically driven path of activation followed by substitution avoids the random encapsulation and ineffective binding of impurities in traditional physical mixing, ensuring that alkaloids and organic acids form stable supramolecular ion-pair complexes according to stoichiometric ratios, thereby improving the utilization rate of effective components.

[0018] 3. This invention effectively overcomes the blood-nerve barrier by constructing a highly lipid-soluble ion-pair system, transforming alkaloids and organic acids, which are originally highly water-soluble and poorly permeable to membranes, into hydrophobic ion-pair complexes. This structure effectively shields the polar groups of drug molecules, significantly improving the oil-water partition coefficient and lipid solubility of the composition, enabling it to penetrate the thickened vascular basement membrane and blood-nerve barrier of diabetic patients more efficiently. This achieves targeted delivery of drug molecules to damaged nerve tissue, solving the problem of drug target delivery in the treatment of diabetic neuropathy. Detailed Implementation

[0019] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example: Example 1 This embodiment provides a method for preparing a traditional Chinese medicine for treating diabetic neuropathy, comprising: Ingredient formula: Component A: Coptis chinensis 300g, Corydalis yanhusuo 220g; Component B: Schisandra chinensis 280g, Cornus officinalis 200g, Astragalus membranaceus 220g; Component C: Cinnamomum cassia 100g.

[0021] Preparation steps: S1. Low-temperature differential pretreatment: Place component A in a cryogenic grinder and grind it through a 150-mesh sieve at -20℃, controlling the moisture content to 1.0wt%. Mix component B and component C and grind them through a 100-mesh sieve at -5℃, controlling the moisture content to 4.0wt%.

[0022] S2. Gas-phase assisted mechanical activation: Pretreated components A and C are placed into a high-pressure planetary ball mill jar, along with zirconia grinding balls. The ball-to-material mass ratio is set to 20:1. The jar is sealed, evacuated, and then filled with carbon dioxide gas, pressurized to 1.2 MPa. The ball mill is started, and the speed is set to 375 rpm for unidirectional continuous grinding for 20 minutes. During the ball milling process, the temperature inside the jar is maintained at 25-30℃ using jacket cooling water.

[0023] S3. In-situ selective assembly: Pause ball milling, maintain a slight positive pressure inside the tank, and quickly add pretreated component B. Replenish with carbon dioxide gas and adjust the tank pressure to 1.8 MPa. Adjust the ball mill's operating mode to pulse grinding: set the speed to 575 rpm, and cycle through forward rotation for 3 minutes, stop for 1 minute, and reverse rotation for 3 minutes. The total grinding time is 60 minutes. At this point, the material transforms into a reddish-brown, oily, semi-solid state.

[0024] S4. Phase Transformation and Integrated Extraction: Stop the ball mill and connect the milling vessel to the extraction loop. Pump carbon dioxide into the vessel and heat it to 30 MPa and 48°C, converting the carbon dioxide into a supercritical fluid. Maintain these conditions and circulate the extract at a flow rate of 30 L / h for 90 minutes. The extractant then enters the desorption vessel for separation at 5 MPa and 35°C, and the extract is collected.

[0025] S5. Formulation: The collected extract is degassed under vacuum at 35°C for 30 minutes to remove residual carbon dioxide, resulting in a reddish-brown oily traditional Chinese medicine composition.

[0026] Example 2 This embodiment provides a method for preparing a traditional Chinese medicine for treating diabetic neuropathy, comprising: Ingredient formula: Component A: 200g Coptis chinensis, 150g Corydalis yanhusuo; Component B: 200g Schisandra chinensis, 150g Cornus officinalis, 150g Astragalus membranaceus; Component C: 50g Cinnamomum cassia.

[0027] Preparation steps: S1. Low-temperature differential pretreatment: Component A is pulverized at -15℃, and the moisture content is controlled to be 1.8wt%. Component B and component C are mixed and pulverized at 0℃, and the moisture content is controlled to be 3.0wt%.

[0028] S2. Gas-phase assisted mechanical activation: Add component A and component C to the ball mill jar, setting the ball-to-material mass ratio to 15:1. Introduce carbon dioxide gas and pressurize to 0.8 MPa. Start the ball mill, setting the speed to 300 rpm, and grind continuously for 15 minutes. Control the temperature inside the jar to below 35℃.

[0029] S3. In-situ stereoselective assembly: Add component B and supplement with carbon dioxide gas to adjust the pressure to 1.5 MPa. Use pulse grinding mode, set the speed to 500 rpm, and the total grinding time is 45 minutes.

[0030] S4. Phase Transformation and Integrated Extraction: Increase the pressure inside the ball mill jar to 25 MPa and the temperature to 40°C. Maintain the supercritical state and circulate for extraction at a flow rate of 20 L / h for 60 minutes. The desorption conditions are: pressure 4 MPa and temperature 30°C.

[0031] S5. Formulation: Collect the extract and degas it under vacuum at 30°C to obtain a dark brown semi-solid paste.

[0032] Example 3 This embodiment provides a method for preparing a traditional Chinese medicine for treating diabetic neuropathy, comprising: Ingredient formula: Component A: Coptis chinensis 400g, Corydalis yanhusuo 300g; Component B: Schisandra chinensis 350g, Cornus officinalis 250g, Astragalus membranaceus 300g; Component C: Cinnamomum cassia 150g.

[0033] Preparation steps: S1. Low-temperature differential pretreatment: Component A is pulverized at -25℃, and the moisture content is controlled to be 0.5wt%. Component B and component C are mixed and pulverized at -10℃, and the moisture content is controlled to be 5.0wt%.

[0034] S2. Gas-phase assisted mechanical activation: Add component A and component C to the ball mill jar, setting the ball-to-material mass ratio to 25:1. Introduce carbon dioxide gas and pressurize to 1.5 MPa. Start the ball mill, setting the speed to 450 rpm, and grind continuously for 30 minutes. Control the temperature inside the jar to below 35°C.

[0035] S3. In-situ stereoselective assembly: Add component B and supplement with carbon dioxide gas to adjust the pressure to 2.0 MPa. Use pulse grinding mode, set the speed to 650 rpm, and the total grinding time is 90 minutes.

[0036] S4. Phase Transformation and Integrated Extraction: Increase the pressure inside the ball mill jar to 35 MPa and the temperature to 55°C. Maintain the supercritical state and circulate for extraction at a flow rate of 40 L / h for 120 minutes. The desorption conditions are: pressure 6 MPa and temperature 40°C.

[0037] S5. Formulation: Collect the extract and degas it under vacuum at 40°C to obtain a reddish-brown viscous oily substance.

[0038] Comparative Example 1 Compared with Example 1, the difference is that: during the ball milling reaction in steps S2 and S3, pressurized carbon dioxide gas was not introduced, but ball milling was carried out under normal air pressure; in the subsequent step S4, carbon dioxide was directly introduced for supercritical extraction. The remaining raw material ratios and process parameters are the same.

[0039] Comparative Example 2 Compared to Example 1, the difference lies in the use of a one-pot feeding and grinding method. Specifically, in step S2, components A, B, and C are all added to the ball mill jar at once, carbon dioxide is directly introduced to 1.8 MPa, and the mixture is continuously ground for 80 minutes according to the parameters of step S3. The remaining raw materials and subsequent processing steps are the same.

[0040] Comparative Example 3 The difference from Example 1 is that the raw material formulation does not contain component C; only components A and B are used, and the preparation is carried out according to the proportions and process steps of Example 1. Everything else is the same.

[0041] Comparative Example 4 Compared with Example 1, the difference lies in the fact that the preparation process adopts the traditional ethanol reflux extraction method. The specific steps are as follows: Components A, B and C in the proportion of Example 1 are mixed and pulverized into coarse powder, 8 times the amount of 75% ethanol is added, and the mixture is heated and refluxed twice, each time for 1.5 hours; the extracts are combined, the ethanol is recovered under reduced pressure until there is no alcohol odor, and the extract is dried under vacuum at 60°C to obtain the extract.

[0042] Test Example 1: Evaluation of Lipid Solubility Experimental materials and instruments The traditional Chinese medicine compositions prepared in Examples 1 to 3, as well as the products prepared in Comparative Examples 1, 2 and 4, were selected as test samples.

[0043] Experimental reagents: n-octanol, deionized water, methanol, potassium dihydrogen phosphate.

[0044] Main instruments: constant temperature shaker, high-speed refrigerated centrifuge, high-performance liquid chromatograph.

[0045] Experimental steps Solvent system preparation: Place an appropriate amount of n-octanol and deionized water in a separatory funnel and shake thoroughly for 24 hours to allow the two phases to reach mutual saturation. After standing and separating the layers, water-saturated n-octanol and water-saturated n-octanol are obtained.

[0046] Preparation of test solutions: Accurately weigh appropriate amounts of each group of test samples and place them in stoppered conical flasks. Accurately add 20 mL of water-saturated n-octanol and sonicate for 10 minutes to aid dispersion.

[0047] Equilibrium distribution: Accurately add 20 mL of water saturated with n-octanol to the conical flask. Place the conical flask in a constant temperature shaker at 25 ± 0.5 °C and shake at 150 rpm in the dark for 24 hours to ensure that the solute reaches thermodynamic equilibrium distribution between the two phases.

[0048] Phase separation: Take the shaken mixture and transfer it to a centrifuge tube. Centrifuge at 4000 rpm for 10 minutes. Carefully aspirate the upper alcohol phase and the lower aqueous phase and filter them separately through a 0.45 μm microporous membrane.

[0049] Content determination: The peak areas of berberine in the alcohol and aqueous phases were determined by high performance liquid chromatography (HPLC), and the concentrations were calculated by substituting the values ​​into the standard curve. Chromatographic conditions: C18 column, mobile phase: acetonitrile-0.05 mol / L potassium dihydrogen phosphate solution, detection wavelength: 265 nm, column temperature: 30 °C.

[0050] Data calculation: According to the formula Calculate the distribution coefficients and take the logarithm to obtain... value.

[0051] The experimental results of the n-octanol-water partition coefficient of each group of samples are shown in Table 1.

[0052] Table 1. Results of n-octanol-water partition coefficient determination for each group of samples. Results Analysis Table 1 shows that the LogP values ​​of the samples prepared in Examples 1 to 3 are all above 1.80, exhibiting significant lipophilic characteristics, while the LogP value of Comparative Example 4 is negative. This difference is attributed to the change in chemical form during the preparation process. Products obtained by traditional solvent extraction mainly exist in the form of alkaloid hydrochloride or sulfate, which are highly polar and water-soluble. In contrast, the embodiments of this invention utilize a gas-phase assisted solid-phase reaction to successfully replace the ionic bond binding sites on the alkaloid molecules with organic acid acceptors, forming supramolecular ion-pair complexes with hydrophobic alkyl or cyclic structures as the outer layer. This complex shields the polar charge centers inside the molecule, thereby significantly improving its solubility in nonpolar solvents.

[0053] The LogP value of Comparative Example 1 was only -0.29, significantly lower than that of the other examples. This indicates that, in the absence of a pressurized carbon dioxide atmosphere, simple mechanical grinding cannot effectively overcome the solid-state lattice energy barrier between alkaloids and organic acids. Because the carbon dioxide activation-carbamate intermediate generation process is not performed, the alkaloid molecules remain in a low-activity lattice-bound state, making it difficult for them to undergo deep chemical bonding with organic acids. The products are mainly physical mixtures or only undergo a small amount of reaction on the particle surface, resulting in strong overall hydrophilicity and failing to achieve an effective conversion from water-soluble to lipid-soluble.

[0054] The LogP value of Comparative Example 2 was 0.68, which, although higher than that of Comparative Example 1, was still significantly lower than that of the stepwise operation example. This confirms the necessity of the stepwise ligand substitution process. In the one-pot system, carbon dioxide, small molecule media, and large molecule organic acids simultaneously compete for the binding sites of alkaloids, causing thermodynamically unstable intermediate states to fail to transform into stable final states in an orderly manner. The disordered competitive reaction results in some alkaloids not being completely encapsulated by the large molecule organic acids or forming incomplete binding states, limiting the improvement of the overall lipophilicity of the final product. Only through specific temporal control of gas-phase activation followed by directional substitution can the formation of high-purity ion-pair complexes with uniform structure and strong lipophilicity be ensured.

[0055] Test Example 2: Determination of Key Component Transfer Rate Experimental materials and instruments The test samples were the final products prepared in Examples 1 to 3, and Comparative Examples 1, 2 and 4.

[0056] The control material was the original medicinal material mixed powder from the corresponding batches in each example and comparative example.

[0057] Experimental reagents: methanol, hydrochloric acid, acetonitrile, phosphoric acid.

[0058] Main instruments: ultrasonic cleaner, rotary evaporator, high performance liquid chromatograph.

[0059] Experimental steps Determination of Total Raw Material Content: Accurately weigh 2.0 g of the mixed raw material powder and place it in a 100 mL stoppered conical flask. Add 50 mL of methanol-hydrochloric acid mixed solution and weigh. Sonicate for 45 minutes, cool, and weigh again. Make up the weight loss with methanol. Shake well, filter, and use the filtrate as the raw material reference solution. Determine the contents of berberine and schisandrol A using HPLC, and calculate the initial total amount in the raw material. .

[0060] Content determination of finished product: Accurately weigh an appropriate amount of the final Chinese herbal product obtained from each group, place it in a 50mL volumetric flask, add methanol, sonicate to dissolve and dilute to the mark, shake well, filter, and use as the test solution. Determine the content of berberine and schisandrol A under the same chromatographic conditions, and calculate the actual total amount of this component in the product. .

[0061] Chromatographic conditions: C18 column; mobile phase A was acetonitrile, mobile phase B was 0.1% phosphoric acid aqueous solution, gradient elution was performed; flow rate was 1.0 mL / min; detection wavelengths were 230 nm and 265 nm; column temperature was 30 ℃.

[0062] Data calculation: According to the formula Calculate the process transfer rate of each key component.

[0063] Experimental results The results of the transfer rate determination of key active ingredients in each group of samples are shown in Table 2.

[0064] Table 2 Results of process transfer rate determination of key active ingredients Results Analysis Table 2 shows that the berberine transfer rate in Examples 1 to 3 remained between 89.70% and 93.30%, and the schisandrol A transfer rate remained between 91.29% and 94.80%. In contrast, the berberine transfer rate in Comparative Example 1 was only 16.70%. This significant difference verifies the decisive role of gas-phase activation in the integrated solid-phase reaction-extraction process. In the examples, high-pressure carbon dioxide, as a reactant, participated in the disruption of the alkaloid lattice energy, inducing the formation of hydrophobic ion-pair complexes that can dissolve in supercritical fluids. Therefore, in the subsequent supercritical carbon dioxide extraction stage, the product was efficiently carried out. In Comparative Example 1, due to the lack of a gas-phase activation step, the alkaloids still existed in the form of highly polar hydrochloride, which has extremely low solubility in supercritical carbon dioxide. This resulted in most of the effective components remaining in the residue in the ball mill jar and unable to be extracted, proving that simple physical mixing cannot achieve efficient transfer of polar components in non-polar supercritical fluids.

[0065] The berberine transfer rate in Comparative Example 2 was 65.70%, significantly lower than the 93.30% in Example 1. This indicates that the stepwise ligand substitution process has a direct impact on the reaction conversion rate. In a one-pot system, carbon dioxide, small molecule mediators, and large molecule organic acid acceptors simultaneously compete for the active sites of alkaloids. This disordered competition results in a large number of incompletely converted intermediates or physical coatings within the reaction system. These components, which do not form stable ion pairs, have poor solubility in the supercritical extraction stage, thus reducing the yield of the final product. The specific timing sequence used in the examples—first gas-phase activation to form intermediates, then introducing acceptor-directed substitution—ensures that the reaction proceeds completely along a thermodynamically favorable direction, maximizing the proportion of ion-pair products that can be recognized and extracted by the supercritical fluid.

[0066] Furthermore, the transfer rate data of the embodiments are also higher than those of Comparative Example 4. Although traditional solvent extraction has good solubility for polar components, it is difficult to achieve complete release of components due to the limitations of solvent penetration rate to plant cell walls and adsorption effect of cell matrix. This invention disrupts the cell wall structure and crystal lattice structure of the raw material at the microscale through mechanochemical action, and combined with the high diffusion coefficient and zero surface tension characteristics of supercritical fluid, achieves deep mass transfer of active ingredients from plant matrix to fluid phase. Data confirms that the coupling technology of gas-phase assisted mechanochemical and supercritical fluid extraction is superior to the traditional liquid-phase solvothermal extraction process in terms of extraction efficiency.

[0067] Test Example 3: In Vitro Transmembrane Permeability Test Experimental materials and instruments: The test samples were the final products prepared in Examples 1 to 3, and Comparative Examples 3 and 4.

[0068] Experimental membrane material: transdermal diffusion simulation membrane.

[0069] Receiving solution: phosphate buffer containing 20% ​​ethanol to increase the solubility of poorly soluble components in the receiving solution and ensure the conditions of the sink.

[0070] Main instruments: transdermal diffusion tester, high performance liquid chromatograph.

[0071] Experimental steps Diffusion cell preparation: The transdermal diffusion simulation membrane is fixed between the supply and receiving chambers of the Franz diffusion cell, with the smooth side of the membrane facing the supply chamber. The receiving chamber is filled with degassed receiving liquid to remove air bubbles. The circulating water bath is turned on to maintain the temperature at 37±0.5℃, and the magnetic stirrer is turned on.

[0072] Sample addition: Accurately weigh 0.5g of each group of test samples, apply evenly to the surface of the transdermal diffusion simulation membrane, and seal the supply chamber to prevent volatilization.

[0073] Sampling: At 1, 2, 4, 8, 12 and 24 hours after administration, 1.0 mL of receiving solution was taken from the sampling port and immediately replaced with an equal volume of blank receiving solution at the same temperature.

[0074] Sample processing and determination: The collected receiving solution was filtered through a 0.45 μm microporous membrane and used as the test solution. The concentration of berberine was determined by HPLC.

[0075] Data Calculation: Based on the measured concentration and dilution factor, calculate the cumulative permeability per unit area at different time points using the following formula. : ; in, For the first Cumulative permeability per unit area at each sampling point For the volume of the receiving chamber, For the first The concentration measured in the second sample For sampling volume, This represents the effective diffusion area. Regarding time Perform linear regression; the slope represents the steady-state permeation rate. .

[0076] Experimental results The calculated results of the 24-hour cumulative permeability and steady-state permeability rate for each group of samples are shown in Table 3.

[0077] Table 3. In vitro transmembrane permeation performance test data Results Analysis The permeation kinetics data in Table 3 show that the steady-state permeation rates of Examples 1 to 3 ranged from 22.14 to 26.85 μg / cm² / h, significantly higher than those of Comparative Example 4. The alkaloids in traditional solvent extracts mainly exist in hydrophilic salt form, which is difficult to transport across the membrane due to the hydrophobic repulsion of the lipid bilayer structure simulated by transdermal diffusion. However, the products prepared in the examples, under gas-phase assisted mechanical force, formed charge-shielded ion-pair complexes through organic acid ligand substitution. This structure significantly reduced the polarity of the molecules, enabling passive diffusion within the lipid membrane, thus demonstrating the effectiveness of hydrophobic ion-pair modification in overcoming biomembrane barriers.

[0078] The permeation rate of Comparative Example 3 was 15.42 μg / cm² / h, which, although higher than that of the traditional extract, was significantly lower than that of Example 1. This difference in data verifies the permeation-enhancing function of component C in the system. During the preparation of the examples, the volatile oily components in component C not only acted as lattice fillers to improve the contact interface of the solid-phase reaction, but also played a role in altering the fluidity of membrane lipids in the final product. Component C, in conjunction with the ion-pair complex, acted on the lipid membrane, reducing the diffusion resistance of the membrane and thus improving the overall delivery efficiency of drug molecules. If this component is missing, even if ion pairs are formed, the transmembrane efficiency will be limited due to the lack of a synergistic carrier.

[0079] Data from the combined examples and comparative studies demonstrate that the preparation method of this invention constructs a drug delivery system with high membrane permeability through a dual mechanism of gas-phase activation and component synergy. Example 1 achieved the highest permeation rate under preferred process parameters, indicating that under these pressure and rotational speed conditions, the ion pairing of alkaloids and organic acids was most complete, and the distribution of component C around the complex was most favorable for subsequent transmembrane transport. This high permeability directly promotes drug penetration of the epineurium and accumulation in damaged nerve tissue in a physically significant sense.

Claims

1. A traditional Chinese medicine for treating diabetic neuropathy, characterized in that, This traditional Chinese medicine is prepared from the following raw materials in parts by weight: Component A: 20-40 parts Coptis chinensis, 15-30 parts Corydalis yanhusuo; Component B: Schisandra chinensis 20-35 parts, Cornus officinalis 15-25 parts, Astragalus membranaceus 15-30 parts; Component C: 5-15 parts of cinnamon twig.

2. The traditional Chinese medicine for treating diabetic neuropathy according to claim 1, characterized in that, The traditional Chinese medicine is a reddish-brown to dark brown oily or semi-solid paste, and it is obtained through gas-phase assisted solid-phase reaction and supercritical fluid phase transformation extraction without organic solvents.

3. A method for preparing a traditional Chinese medicine for treating diabetic neuropathy as described in any one of claims 1-2, characterized in that, Includes the following steps: S1. Low-temperature differentiated pretreatment: Low-temperature pulverization pretreatment was performed on components A, B and C respectively; S2. Gas-phase assisted mechanical activation: The pretreated component A and component C are put into a high-pressure planetary ball mill jar in proportion, sealed and filled with carbon dioxide gas, and the jar is pressurized to carry out ball milling activation to obtain intermediate material. S3, In-situ three-dimensional selective assembly: Add pretreated component B to the ball mill jar of S2, replenish carbon dioxide gas again, adjust the pressure inside the jar, and continue the ball milling reaction until the material presents an oily semi-solid state; S4. Phase transformation and integrated extraction: Increase the pressure and temperature inside the ball mill jar to convert carbon dioxide into a supercritical fluid state for extraction. After analysis and separation, the extract is obtained. S5. Formulation: Collect the extract after analysis and separation in step S4, perform vacuum degassing to remove residual carbon dioxide, and obtain the traditional Chinese medicine.

4. The method for preparing a traditional Chinese medicine for treating diabetic neuropathy according to claim 3, characterized in that, In step S1, the low-temperature differential pretreatment specifically involves: pulverizing component A at -25°C to -15°C to control the water content to be less than 2.0 wt%; mixing component B and component C and pulverizing them at -10°C to 0°C to control the water content to be between 3.0 and 5.0 wt%.

5. The preparation method of a traditional Chinese medicine for treating diabetic neuropathy according to claim 3, characterized in that, In step S2, when pressurizing the inside of the tank, the pressure is controlled at 0.8-1.5MPa. The process parameters for ball mill activation are: the mass ratio of grinding balls to materials is 15:1 to 25:1, the ball mill speed is 300-450rpm, the grinding time is 15-30 minutes, and the temperature inside the ball mill tank is controlled below 35℃.

6. The method for preparing a traditional Chinese medicine for treating diabetic neuropathy according to claim 3, characterized in that, In step S2, the carbon dioxide gas is in a subcritical pressurized gaseous state, and the alkaloids in component A react with carbon dioxide in situ under the action of mechanical energy to generate carbamate intermediates.

7. The preparation method of a traditional Chinese medicine for treating diabetic neuropathy according to claim 3, characterized in that, In step S3, the pressure inside the tank is adjusted to 1.5-2.0 MPa. The ball milling reaction adopts a pulse grinding mode, specifically: the rotation speed is 500-650 rpm, and the cycle is performed in the forward rotation for 3 minutes - stop for 1 minute - reverse rotation for 3 minutes, with a total grinding time of 45-90 minutes.

8. The preparation method of a traditional Chinese medicine for treating diabetic neuropathy according to claim 3, characterized in that, In step S3, the organic acid in component B undergoes a ligand substitution reaction with the intermediate generated in step S2, displacing carbon dioxide and forming a hydrophobic ion-pair complex.

9. The method for preparing a traditional Chinese medicine for treating diabetic neuropathy according to claim 3, characterized in that, In step S4, the increase of pressure and temperature inside the ball mill jar specifically involves: increasing the pressure to 25-35 MPa and the temperature to 40-55°C; the extraction is performed by circulating extraction at a flow rate of 20-40 L / h for 60-120 minutes; and the separation conditions are: reducing the pressure to 4-6 MPa and the temperature to 30-40°C.

10. A method for preparing a traditional Chinese medicine for treating diabetic neuropathy according to claim 3, characterized in that, In step S5, the temperature of vacuum degassing is 30-40℃, and the obtained traditional Chinese medicine is directly filled into soft capsules or mixed with microcrystalline cellulose to make micro pellets.

Images