Preparation method and application of uremia clearing extract

Abstract

The invention belongs to the technical field of pharmaceutical preparations, and particularly relates to a preparation method and application of uremia clearing extract. The preparation method comprises the following steps: mixing rheum officinale, astragalus membranaceus, white mulberry root-bark, radix sophorae flavescentis, codonopsis pilosula, bighead atractylodes rhizome, poria cocos, radix polygoni multiflori preparata, radix paeoniae alba, salvia miltiorrhiza, ligusticum wallichii, chrysanthemum, ginger processed pinellia, plantain herb, radix bupleuri and liquorice, and soaking in water to obtain a mixture; carrying out microwave extraction, filtering, collecting an extracting solution, and concentrating to obtain clear paste; and adding ethanol into the clear paste for alcohol precipitation, sequentially separating and purifying the supernatant through DM130 and LS-100 macroporous resins, collecting the eluent, and concentrating to obtain the traditional Chinese medicine composition. The preparation method of the uremia clearing extract is optimized, the extracting solution is obtained through microwave extraction, and then the specific purification process is adopted, so that the content of effective components such as paeoniflorin, astragaloside, stilbene glucoside and salvianolic acid B in the extract is obviously increased.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical preparation technology, specifically relating to a method for preparing uremic toxin extract and its application. Background Technology

[0002] Chronic renal failure is a common kidney disease characterized by a gradual decline in kidney function, eventually leading to uremia.

[0003] Uremic Clearing is a traditional Chinese medicine, mainly used to clear the bowels and reduce turbidity, strengthen the spleen and promote diuresis, and promote blood circulation and remove blood stasis. It is used to treat chronic renal failure, azotemia, early uremia, and those with spleen deficiency and dampness syndrome or spleen deficiency and blood stasis syndrome according to traditional Chinese medicine diagnosis. It can reduce creatinine and blood urea nitrogen, stabilize renal function, and delay dialysis time. It also has a certain effect on improving renal anemia, increasing blood calcium and reducing blood phosphorus. In addition, it has the effects of clearing heat and dampness, promoting blood circulation and relieving pain, dissolving stones and expelling stones. It is mainly used to treat kidney stones, bladder stones and ureteral stones.

[0004] The basic formula of Uremic Clearing Granules uses rhubarb and astragalus as the main ingredients, combined with mulberry bark, sophora flavescens, codonopsis, atractylodes macrocephala, poria cocos, prepared he shou wu, white peony root, salvia miltiorrhiza, chuanxiong rhizome, chrysanthemum, ginger-processed pinellia, plantain, bupleurum, and licorice. In existing technologies, such as Chinese invention patent publication number CN119139412A, a method for preparing Uremic Clearing Capsules is provided. The method for preparing Uremic Clearing Extract mainly involves mixing the raw materials rhubarb, astragalus, mulberry bark, sophora flavescens, codonopsis, atractylodes macrocephala, poria cocos, prepared he shou wu, white peony root, salvia miltiorrhiza, chuanxiong rhizome, chrysanthemum, ginger-processed pinellia, plantain, bupleurum, and licorice, soaking in water, extracting, filtering, and concentrating to obtain the extract. However, in actual production, it is impossible to extract all the effective components of the entire formula when extracting large quantities of Chinese medicinal materials with water, resulting in poor efficacy of the finished product.

[0005] The composition of uremic toxin extract is complex, and how to improve its efficacy through process improvement has been a key research focus for those skilled in the art. Summary of the Invention

[0006] This invention addresses the problems existing in the prior art by providing a method for preparing uremic toxin extract and its application.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for preparing uremic extract, comprising the following steps: (1) Rhubarb, Astragalus, Mulberry bark, Sophora flavescens, Codonopsis pilosula, Atractylodes macrocephala, Poria cocos, processed Polygonum multiflorum, Paeonia lactiflora, Salvia miltiorrhiza, Ligusticum chuanxiong, Chrysanthemum, Pinellia ternata, Plantago asiatica, Bupleurum chinense and Glycyrrhiza uralensis are mixed and soaked in water to obtain a mixture; (2) The mixture is then subjected to microwave extraction, filtered, the extract is collected and concentrated to obtain a clear extract; (3) Add ethanol to the clear extract for alcohol precipitation, and then separate and purify the upper layer by passing it through DM130 and LS-100 macroporous resins in sequence. Collect the eluent, concentrate it, and you will get the product.

[0008] Preferably, the mass ratio of rhubarb, astragalus, mulberry bark, sophora flavescens, codonopsis, atractylodes macrocephala, poria cocos, prepared he shou wu, white peony root, salvia miltiorrhiza, chuanxiong rhizome, chrysanthemum, ginger pinellia, plantain, bupleurum and licorice in step (1) is 1:3-5:2-5:1-4:2-5:3-7:4-6:3-6:2-4:3-6:2-4:2-3:1-2:4-6:1-2:0.5-1.5.

[0009] Preferably, the soaking process in step (1) includes: first, separately pulverizing rhubarb, astragalus, mulberry bark, sophora flavescens, codonopsis, atractylodes macrocephala, poria cocos, prepared he shou wu, white peony root, salvia miltiorrhiza, chuanxiong rhizome, chrysanthemum, ginger-processed pinellia, plantain, bupleurum, and licorice, passing them through a 120-180 mesh sieve, then mixing them, and adding 2-10 times their weight of water to soak for 30-120 min. More preferably, adding 5-10 times their weight of water to soak for 60-120 min.

[0010] Preferably, the microwave extraction temperature in step (2) is 40-60℃, the microwave extraction power is 100-200W, and the microwave extraction time is 30-60 min.

[0011] More preferably, the microwave extraction temperature in step (2) is 45-55℃, the microwave extraction power is 150-180W, and the microwave extraction time is 30-50 min.

[0012] Preferably, the concentration in step (2) adopts double-effect concentration, and the process parameters of the double-effect concentration include the temperature of the first-effect concentration being 50-60℃, the pressure of the first-effect concentration being -0.07~-0.06 MPa, and the time of the first-effect concentration being 4-5 h; the temperature of the second-effect concentration being 40-50℃, the pressure of the second-effect concentration being -0.09~-0.08 MPa, and the time of the second-effect concentration being 6-7 h.

[0013] More preferably, the process parameters for the dual-effect concentration include a first-effect concentration temperature of 55-60℃, a first-effect concentration pressure of -0.07 to -0.06 MPa, and a first-effect concentration time of 4.5-5 h; and a second-effect concentration temperature of 45-50℃, a second-effect concentration pressure of -0.09 to -0.08 MPa, and a second-effect concentration time of 6.5-7 h.

[0014] Preferably, the relative density of the extract in step (2) is 1.1-1.3 g / mL.

[0015] Preferably, the volume fraction of ethanol in step (3) is 60-90%.

[0016] More preferably, the volume fraction of ethanol in step (3) is 60-80%.

[0017] Preferably, the mass ratio of the ointment to ethanol in step (3) is 1:4-8.

[0018] Preferably, the alcohol precipitation time in step (3) is 8-12 h.

[0019] Preferably, the separation and purification process in step (3) includes: the upper layer is first passed through DM130 macroporous resin with a sample volume of 2-4 Bv and a sample flow rate of 1-3 Bv / h, and then eluted sequentially with 3-5 Bv of water and 4-6 Bv of ethanol with a volume fraction of 50-80%. The ethanol eluent is collected, and then the ethanol eluent is concentrated to a relative density of 1.1-1.3 g / mL and passed through LS-100 macroporous resin with a sample volume of 1-2 Bv and a sample flow rate of 1-2 Bv / h, and then eluted sequentially with 1-3 Bv of water and 1-2 Bv of ethanol with a volume fraction of 60-80%, with an elution flow rate of 1-2 Bv / h for both elutions.

[0020] Preferably, the concentration in step (3) is vacuum concentration or reduced pressure concentration.

[0021] Preferably, the relative density of the uremic extract in step (3) is 1.1-1.5 g / mL.

[0022] The present invention also provides the application of the uremic extract prepared by the above preparation method in the preparation of drugs for treating chronic nephritis.

[0023] Compared with the prior art, the present invention has the following beneficial effects: This invention optimizes the preparation method of uremic toxin extract. The extract is obtained by microwave extraction of raw medicinal materials, and then a specific purification process is adopted to significantly increase the content of effective components such as paeoniflorin, astragaloside A, stilbene glycoside and salvianolic acid B in the extract. Detailed Implementation

[0024] It is worth noting that the raw materials used in this invention are all commercially available products.

[0025] Example 1 A method for preparing a uremic extract, comprising the following steps: (1) Weigh out 30 parts of rhubarb, 120 parts of astragalus, 120 parts of mulberry bark, 60 parts of sophora flavescens, 90 parts of codonopsis, 180 parts of atractylodes macrocephala, 150 parts of poria cocos, 120 parts of processed fleeceflower root, 90 parts of white peony root, 150 parts of salvia miltiorrhiza, 90 parts of chuanxiong rhizome, 60 parts of chrysanthemum, 30 parts of ginger-processed pinellia, 150 parts of plantain, 30 parts of bupleurum and 30 parts of licorice. Grind the 16 medicinal materials into powder, pass them through a 150-mesh sieve, and then mix them. Soak them in 8 times their weight of water for 90 minutes to obtain the mixture.

[0026] (2) The mixture was then placed in a microwave reactor and extracted at 50°C and 180 W for 30 min. After filtration, the extract was collected and placed in a double-effect concentrator. The temperature of the first-effect concentration was controlled at 55°C and the pressure at -0.07 MPa for 5 h. The temperature of the second-effect concentration was controlled at 50°C and the pressure at -0.08 MPa for 7 h, to obtain a clear extract with a relative density of 1.2 g / mL.

[0027] (3) After adding 65% ethanol (volume fraction) to the extract and precipitating for 10 h (mass ratio of extract to ethanol is 1:6), the supernatant is first passed through DM130 macroporous resin with a sample volume of 3 Bv and a sample flow rate of 2 Bv / h. It is then eluted with 4 Bv of water and 5 Bv of 60% ethanol, and the ethanol eluent is collected. The ethanol eluent is then concentrated to a relative density of 1.2 g / mL and passed through LS-100 macroporous resin with a sample volume of 1.5 Bv and a sample flow rate of 2 Bv / h. It is then eluted with 2 Bv of water and 2 Bv of 60% ethanol, with an elution flow rate of 1 Bv / h for both. The eluent is collected and concentrated under vacuum to obtain uremic extract with a relative density of 1.2 g / mL.

[0028] Example 2 A method for preparing a uremic extract, comprising the following steps: (1) Weigh out 30 parts of rhubarb, 150 parts of astragalus, 150 parts of mulberry bark, 120 parts of sophora flavescens, 60 parts of codonopsis, 90 parts of atractylodes macrocephala, 120 parts of poria cocos, 90 parts of processed fleeceflower root, 60 parts of white peony root, 90 parts of salvia miltiorrhiza, 120 parts of chuanxiong rhizome, 90 parts of chrysanthemum, 60 parts of ginger-processed pinellia, 180 parts of plantain, 60 parts of bupleurum, and 45 parts of licorice. Grind the 16 medicinal materials into powder, pass them through a 120-mesh sieve, mix them, and soak them in 5 times their weight of water for 60 minutes to obtain a mixture.

[0029] (2) The mixture was then placed in a microwave reactor and extracted for 40 min at 40℃ and 200 W. After filtration, the extract was collected and placed in a double-effect concentrator. The temperature of the first-effect concentration was controlled at 60℃ and the pressure at -0.06 MPa for 4 h. The temperature of the second-effect concentration was controlled at 40℃ and the pressure at -0.09 MPa for 6 h, to obtain a clear extract with a relative density of 1.1 g / mL.

[0030] (3) After adding 60% ethanol (volume fraction) to the extract for 8 h (mass ratio of extract to ethanol is 1:8), the supernatant is first passed through DM130 macroporous resin with a sample volume of 2 Bv and a sample flow rate of 1 Bv / h. It is then eluted with 3 Bv of water and 4 Bv of 50% ethanol, and the ethanol eluent is collected. The ethanol eluent is then concentrated to a relative density of 1.3 g / mL and passed through LS-100 macroporous resin with a sample volume of 2 Bv and a sample flow rate of 1 Bv / h. It is then eluted with 2 Bv of water and 1 Bv of 60% ethanol, with a flow rate of 2 Bv / h for both elutions. The eluent is collected and concentrated under vacuum to obtain uremic extract with a relative density of 1.5 g / mL.

[0031] Example 3 A method for preparing a uremic extract, comprising the following steps: (1) Weigh out 30 parts of rhubarb, 90 parts of astragalus, 60 parts of mulberry bark, 30 parts of sophora flavescens, 150 parts of codonopsis, 210 parts of atractylodes macrocephala, 180 parts of poria cocos, 180 parts of processed fleeceflower root, 120 parts of white peony root, 180 parts of salvia miltiorrhiza, 60 parts of chuanxiong rhizome, 60 parts of chrysanthemum, 30 parts of ginger-processed pinellia, 120 parts of plantain, 30 parts of bupleurum and 15 parts of licorice. Grind the 16 medicinal materials into powder, pass them through a 180-mesh sieve, mix them, and soak them in 10 times their weight of water for 120 minutes to obtain the mixture.

[0032] (2) The mixture was then placed in a microwave reactor and extracted at 60°C and 100 W for 60 min. After filtration, the extract was collected and placed in a double-effect concentrator. The temperature of the first-effect concentration was controlled at 50°C and the pressure at -0.07 MPa for 5 h. The temperature of the second-effect concentration was controlled at 50°C and the pressure at -0.09 MPa for 7 h, to obtain a clear extract with a relative density of 1.3 g / mL.

[0033] (3) After adding 90% ethanol (volume fraction) to the extract and precipitating for 12 h (mass ratio of extract to ethanol is 1:4), the supernatant is first passed through DM130 macroporous resin with a loading volume of 4 Bv and a loading flow rate of 3 Bv / h. It is then eluted with 5 Bv of water and 6 Bv of 80% ethanol, and the ethanol eluent is collected. The ethanol eluent is then concentrated to a relative density of 1.1 g / mL and passed through LS-100 macroporous resin with a loading volume of 1 Bv and a loading flow rate of 2 Bv / h. It is then eluted with 3 Bv of water and 1 Bv of 80% ethanol, with a elution flow rate of 1 Bv / h for both. The eluent is collected and concentrated under vacuum to obtain uremic extract with a relative density of 1.1 g / mL.

[0034] Comparative Example 1 A method for preparing a uremic extract, comprising the following steps: Weigh out 30 parts by weight of rhubarb, 120 parts by astragalus, 120 parts by mulberry bark, 60 parts by sophora flavescens, 90 parts by codonopsis, 180 parts by atractylodes macrocephala, 150 parts by poria cocos, 120 parts by processed fleeceflower root, 90 parts by white peony root, 150 parts by salvia miltiorrhiza, 90 parts by chuanxiong rhizome, 60 parts by chrysanthemum, 30 parts by ginger-processed pinellia, 150 parts by plantain, 30 parts by bupleurum, and 30 parts by licorice. Grind the 16 herbs into powder, pass them through a 150-mesh sieve, mix them together, and decoct them three times with 8 times their weight of water. The first and second decoctions are 2 hours each, and the third decoction is 1 hour. Combine the decoctions, filter them, and concentrate the filtrate to obtain a uremic toxin-clearing extract with a relative density of 1.2 g / mL.

[0035] Comparative Example 2 Compared with Example 1, the only difference is that in step (2), the temperature of the first-effect concentration is controlled at 90°C, the pressure is -0.04 MPa, and the concentration is 5 h; the temperature of the second-effect concentration is controlled at 80°C, the pressure is -0.06 MPa, and the concentration is 7 h, resulting in a clear paste with a relative density of 1.5 g / mL.

[0036] Comparative Example 3 Compared with Example 1, the only difference is that alcohol precipitation is not performed in step (3).

[0037] Comparative Example 4 Compared with Example 1, the only difference is that the volume fraction of ethanol in step (3) is 50%.

[0038] Comparative Example 5 Compared with Example 1, the only difference is that the upper liquid in step (3) passes only through DM130 macroporous resin.

[0039] Comparative Example 6 Compared with Example 1, the only difference is that the upper liquid in step (3) is passed only through LS-100 macroporous resin.

[0040] Comparative Example 7 Compared with Example 1, the only difference is that the LS-100 macroporous resin in step (3) is replaced with HPD-400 macroporous resin.

[0041] Test Example 1 The contents of the active ingredients (paeoniflorin, astragaloside A, stilbene glycoside, and salvianolic acid B) in the uremic extracts prepared in Examples 1-3 and Comparative Examples 1-7 were determined by the following methods: 1. Reagents and reference standards: Acetonitrile, methanol and phosphoric acid were all of analytical grade. The purity of paeoniflorin, astragaloside A, stilbene glycoside and salvianolic acid B reference standards was ≥98%.

[0042] 2. Preparation of reference solutions: Accurately weigh 10 mg of each of the following reference standards: paeoniflorin, astragaloside A, stilbene glycoside, and salvianolic acid B, dried to constant weight at 80℃. Place them in a 50 mL volumetric flask, add water to dissolve and dilute to the mark. Accurately measure 5 mL of each reference standard and place it in a 25 mL volumetric flask. Add water to the mark and shake well to obtain the reference solution.

[0043] Preparation of test solution: Take 3 g each of the uremic extract prepared in Examples 1-3 and Comparative Examples 1-7, weigh accurately, place in a stoppered conical flask, add 25 mL of water accurately, shake well, sonicate for 30 min (power 120 W, frequency 40 kHz), cool and weigh again, make up the lost weight with water, shake well, filter with a 0.45 μm microporous membrane, and use the filtrate as the test solution.

[0044] 3. HPLC conditions Column: Agilent Zorbax SB-C18 (250×4.6mm, 5μm).

[0045] Mobile phase: A: 0.1% aqueous phosphoric acid solution; B: acetonitrile. Gradient elution program is shown in Table 1.

[0046] Detection wavelengths: paeoniflorin: 230 nm; astragaloside A: 203 nm; stilbene glycoside: 320 nm; salvianolic acid B: 286 nm.

[0047] Flow rate: 1.0 mL / min.

[0048] Column temperature: 25℃.

[0049] Injection volume: 10 μL.

[0050] Table 1 Gradient elution program

[0051] The yield calculation formula is as follows: Yield (%) = (M)实际 ÷M 理论 ) × 100% Where: M 实际 This refers to the detected content of the active ingredient, M. 理论 This refers to the theoretical content of the active ingredient.

[0052] 4. Experimental Results: The results are shown in Table 2. As can be seen from Table 2, the yields and purity of paeoniflorin, astragaloside A, stilbene glycoside, and salvianolic acid B in the uremic extract of Examples 1-3 were higher than those in Comparative Examples 1-7, indicating that the extraction method of the present invention can effectively improve the yield and purity of the active ingredients, thereby enhancing the pharmacological activity of the uremic extract.

[0053] Table 2 Test Data

[0054] Test Example 2 Animal experiments were conducted on the uremic extract prepared in Example 1 and Comparative Examples 1-7 to treat chronic nephritis.

[0055] 1. Laboratory animals One hundred and ten Wistar rats were used, each weighing 200 ± 10 g.

[0056] 2. Experimental drugs The uremic extract prepared in Example 1 and Comparative Examples 1-7.

[0057] 3. Grouping and Modeling One hundred and ten rats were randomly divided into 11 groups: blank control group, model group, positive control group, Example 1, and comparative examples 1-7. Except for the blank control group, the other groups of rats were given adenine 300 mg / kg daily according to their body weight, while the blank control group was given a normal diet. The model of glomerulonephritis was induced after 15 days. The appearance of proteinuria after modeling indicated that the model was successful.

[0058] 4. Experimental Methods In Example 1 and Comparative Examples 1-7, rats were administered the corresponding drugs by gavage at a dose of 0.5 g / 100 g body weight. Rats in the positive control group were administered Uremic Clearing Granules (purchased from Guangzhou Kangchen Pharmaceutical) by gavage at a dose of 0.5 g / 100 g body weight once daily. The blank control group and model group were administered an equal volume of physiological saline by gavage. The administration was continued for 6 weeks. Blood samples were collected 1 hour after the last administration for the determination of biochemical indicators, including urinary creatinine, blood urea nitrogen, and urinary protein levels.

[0059] 5. Experimental Results The biochemical index content is shown in Table 3. As can be seen from Table 3, the uremic toxin extract of the present invention has better efficacy in treating chronic nephritis than commercially available uremic toxin granules, and has good social and economic benefits.

[0060] Table 3 Biochemical index content

[0061] Note: Compared with the model group, # express p <0.05, ## express p <0.01, ### express p <0.001.

[0062] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a uremic extract, characterized in that, Includes the following steps: (1) Rhubarb, Astragalus, Mulberry bark, Sophora flavescens, Codonopsis pilosula, Atractylodes macrocephala, Poria cocos, processed Polygonum multiflorum, Paeonia lactiflora, Salvia miltiorrhiza, Ligusticum chuanxiong, Chrysanthemum, Pinellia ternata, Plantago asiatica, Bupleurum chinense and Glycyrrhiza uralensis are mixed and soaked in water to obtain a mixture; (2) The mixture is then subjected to microwave extraction, filtered, the extract is collected and concentrated to obtain a clear extract; (3) Add ethanol to the extract for alcohol precipitation, and then separate and purify the upper layer by passing it through DM130 and LS-100 macroporous resins. Collect the eluent, concentrate it, and you will get the uremic extract.

2. The preparation method according to claim 1, characterized in that, The mass ratio of rhubarb, astragalus, mulberry bark, sophora flavescens, codonopsis, atractylodes macrocephala, poria cocos, prepared he shou wu, white peony root, salvia miltiorrhiza, chuanxiong rhizome, chrysanthemum, ginger pinellia, plantain, bupleurum and licorice in step (1) is 1:3-5:2-5:1-4:2-5:3-7:4-6:3-6:2-4:3-6:2-4:2-3:1-2:4-6:1-2:0.5-1.

5.

3. The preparation method according to claim 1, characterized in that, The soaking process described in step (1) includes: first, pulverizing rhubarb, astragalus, mulberry bark, sophora flavescens, codonopsis, atractylodes macrocephala, poria cocos, prepared he shou wu, white peony root, salvia miltiorrhiza, chuanxiong rhizome, chrysanthemum, ginger pinellia, plantain, bupleurum and licorice, passing them through a 120-180 mesh sieve, then mixing them, and adding 2-10 times their weight of water to soak for 30-120 minutes.

4. The preparation method according to claim 3, characterized in that, The microwave extraction temperature in step (2) is 40-60℃, the microwave extraction power is 100-200 W, and the microwave extraction time is 30-60 min.

5. The preparation method according to claim 1, characterized in that, In step (2), the concentration adopts double-effect concentration. The process parameters of the double-effect concentration include the temperature of the first-effect concentration being 50-60℃, the pressure of the first-effect concentration being -0.07~-0.06Mpa, and the time of the first-effect concentration being 4-5 h. The temperature of the second-effect concentration is 40-50℃, the pressure of the second-effect concentration is -0.09~-0.08Mpa, and the time of the second-effect concentration is 6-7 h.

6. The preparation method according to claim 1, characterized in that, The relative density of the ointment described in step (2) is 1.1-1.3 g / mL.

7. The preparation method according to claim 1, characterized in that, In step (3), the volume fraction of ethanol is 60-90%; the mass ratio of the extract to ethanol is 1:4-8; and the alcohol precipitation time is 8-12 h.

8. The preparation method according to claim 1, characterized in that, In step (3), the separation and purification process includes: the upper layer is first passed through DM130 macroporous resin with a sample volume of 2-4 Bv and a sample flow rate of 1-3 Bv / h, and then eluted sequentially with 3-5 Bv of water and 4-6 Bv of ethanol with a volume fraction of 50-80%. The ethanol eluent is collected, and then the ethanol eluent is concentrated to a relative density of 1.1-1.3 g / mL and then passed through LS-100 macroporous resin with a sample volume of 1-2 Bv and a sample flow rate of 1-2 Bv / h, and then eluted sequentially with 1-3 Bv of water and 1-2 Bv of ethanol with a volume fraction of 60-80%, with an elution flow rate of 1-2 Bv / h for both elutions.

9. The preparation method according to claim 8, characterized in that, In step (3), the concentration is vacuum concentration or reduced pressure concentration; the relative density of the uremic extract is 1.1-1.5 g / mL.

10. The application of the preparation method according to any one of claims 1-9 in the preparation of a medicament for treating chronic nephritis.

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