A preparation process of human immunoglobulin preparation for intravenous injection

Abstract

The present invention provides a preparation process of a human immunoglobulin preparation for intravenous injection, which belongs to the field of protein production technology. The preparation process provided by the present invention comprises: dissolving the component II+III precipitate with a precipitation dissolving solution containing 0.8%-1.2% sodium dihydrogen phosphate and 0.66%-1.0% sodium citrate, adding low-temperature ethanol, adding a filter-aid mixed powder for filter pressing, wherein the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4-5:2-3:1-1.5. The human immunoglobulin preparation for intravenous injection prepared by the present invention has an anti-complement activity of only 5%-7%, has good thermal stability, and a purity of up to 99.3%-100%.

Description

Technical Field

[0001] The invention belongs to the technical field of protein production, and specifically relates to a preparation process of a human immunoglobulin preparation for intravenous injection. Background Art

[0002] Intravenous immunoglobulin (IVIG) is prepared by mixing plasma collected from a large number of healthy blood donors using apheresis technology and then separated and purified by different methods. IVIG is mainly used to treat primary immunodeficiency, immune-mediated thrombocytopenia, Kawasaki disease, hematopoietic stem cell transplant patients, chronic lymphocytic B-cell leukemia, and pediatric HIV-1 infection. It also has certain therapeutic effects on blood system diseases, gynecological diseases, kidney diseases, rheumatism, and neurological disorders. As people's understanding of IVIG continues to improve, its clinical application is becoming more and more extensive. In recent years, with the continuous increase in clinical indications and the application of new technologies, the demand for IVIG has maintained a high growth momentum among plasma protein products, and this trend continues. Therefore, it is crucial to improve the quality of IVIG products and control the preparation process of IVIG.

[0003] The traditional immunoglobulin production process is a low-temperature ethanol protein separation process. This technology separates component II from component I+II+III precipitation by adjusting the five elements of the low-temperature ethanol method in multiple steps: ionic strength, pH value, temperature, ethanol concentration and protein content, and then further purifies to obtain intravenous human immunoglobulin. This traditional production process uses a two-step method to extract intravenous human immunoglobulin. Its biggest drawback is that the purity of the intravenous human immunoglobulin produced is low, and the content of polymers is high, which is easy to cause adverse reactions after infusion.

[0004] Patent CN101648998A discloses a method for preparing intravenous human immunoglobulin from component I+III or component III, which uses a three-step low-temperature ethanol method to purify human immunoglobulin from components I+III. It has many steps, requires a low temperature operating environment, has high energy consumption, and has many defects such as flammable and explosive ethanol solvents. Ethanol has a certain effect on the structure and function of IgG.

[0005] With the increasing market demand for intravenous human immunoglobulin, the product purity of the existing intravenous human immunoglobulin preparation technology is no longer ideal. Therefore, finding a preparation process for intravenous human immunoglobulin with high product purity, low anti-complement activity and good safety is an urgent problem that needs to be solved. Summary of the invention

[0006] In view of the above shortcomings, the present invention provides a preparation process of a human immunoglobulin preparation for intravenous injection. The preparation process provided by the present invention comprises: dissolving the component II + III precipitate with a precipitation dissolving solution containing 0.8%-1.2% sodium dihydrogen phosphate and 0.66%-1.0% sodium citrate, adding low-temperature ethanol, adding a filter-aid mixed powder for filter pressing, wherein the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4-5:2-3:1-1.5. The human immunoglobulin preparation for intravenous injection prepared by the present invention has an anti-complement activity of only 5%-7%, has good thermal stability, and a purity of up to 99.3%-100%.

[0007] It should be noted that: Component I supernatant, Component I precipitate, Component II + III precipitate, and Component II + III supernatant are common classification methods in the technical field, and in the present invention are names of specific substances; they do not refer to simple serial numbers.

[0008] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0009] In one aspect, the present invention provides a process for preparing a human immunoglobulin preparation for intravenous injection, the process comprising: dissolving component II + III precipitate with a precipitate dissolving solution, adding low-temperature ethanol to obtain a reaction solution, and filtering;

[0010] Specifically, the precipitation dissolving solution contains 0.8%-1.2% sodium dihydrogen phosphate and 0.66%-1.0% sodium citrate.

[0011] Preferably, the precipitation dissolving solution contains 0.9% sodium dihydrogen phosphate and 0.74% sodium citrate.

[0012] Specifically, the ratio of the component II + III precipitate to the precipitate dissolving solution is 1:10-15 w / v.

[0013] Preferably, the ratio of the component II + III precipitate to the precipitate dissolving solution is 1:10 w / v.

[0014] Specifically, the filter pressing requires adding a filter-aid mixed powder to the reaction solution, and the filter-aid mixed powder is a mixture of diatomaceous earth, cellulose and silicon dioxide.

[0015] Preferably, the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4-5:2-3:1-1.5.

[0016] Further preferably, the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4.2:2.5:1.

[0017] Preferably, the amount of the filter aid mixed powder added is 12-15 g / L of reaction solution.

[0018] Specifically, the preparation process also includes using a DEAE-Sepharose FF chromatography column to purify the protein solution loaded on the chromatography column.

[0019] Preferably, the equilibrium solution of the DEAE-Sepharose FF chromatography column is 0.05 mol / L glycine-sodium hydroxide buffer.

[0020] Preferably, the pH of the chromatographic loading protein solution is adjusted to 6.4-6.6 by 0.05 mol / L glycine-sodium hydroxide buffer, and the conductivity is adjusted to 2.05-2.75 s / m by 5% sodium chloride solution.

[0021] Specifically, the preparation process comprises the following steps:

[0022] S1, component II + III precipitate is dissolved with precipitation dissolving solution, and after adding low temperature ethanol, it is filtered by pressure and deep filtration;

[0023] S2, collecting the filtered supernatant, ultrafiltration and dialyzing to obtain dialysate;

[0024] S3, after adjusting the pH and conductivity of the dialysate, a DEAE-Sepharose FF chromatography column was performed;

[0025] S4, collecting the flow-through liquid, dialyzing after ultrafiltration, adding maltose as a protective agent, and obtaining a protein solution;

[0026] S5. After incubation, the protein solution is filtered and packaged to obtain a human immunoglobulin preparation for intravenous injection.

[0027] Preferably, the precipitation dissolving solution in step S1 contains 0.8%-1.2% sodium dihydrogen phosphate and 0.66%-1.0% sodium citrate.

[0028] More preferably, the precipitation dissolving solution in step S1 contains 0.9% sodium dihydrogen phosphate and 0.74% sodium citrate.

[0029] Preferably, the ratio of the component II + III precipitate to the precipitate dissolving solution in step S1 is 1:8-10 w / v.

[0030] Further preferably, the ratio of the component II + III precipitate to the precipitate dissolving solution in step S1 is 1:8 w / v.

[0031] More specifically, the low-temperature ethanol described in step S1 is 90%-95% ethanol at a temperature of -15 to -20°C.

[0032] Preferably, the low-temperature ethanol is 95% ethanol at -15°C.

[0033] Preferably, the volume ratio of ethanol to the supernatant of component I is 17%, and the flow rate of adding ethanol is no more than 1.5 L / min.

[0034] Further preferably, the flow rate of adding ethanol is comprised between 1.0 and 1.5 L / min.

[0035] More specifically, the filter pressing in step S1 requires the addition of a filter-aid mixed powder, wherein the filter-aid mixed powder is a mixture of diatomaceous earth, cellulose and silicon dioxide.

[0036] Preferably, the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4-5:2-3:1-1.5.

[0037] Further preferably, the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4.2:2.5:1.

[0038] Preferably, the amount of the filter aid mixed powder added is 12-15 g / L of reaction solution.

[0039] Further preferably, the amount of the filter aid mixed powder added is 12 g / L of reaction solution.

[0040] Preferably, step S2 comprises adjusting the pH of the supernatant to 3.8-4 with 1 mol / L HCl, concentrating it to 5% by ultrafiltration, and continuously dialyzing it with 5 volumes of 4° C. water for injection, adjusting the protein content to 5%, and obtaining a dialysate.

[0041] Preferably, the pH in step S3 is adjusted to 6.4-6.6 using 0.05 mol / L glycine-sodium hydroxide buffer.

[0042] Preferably, the conductivity is adjusted in step S3 by using 0.5% sodium chloride solution to adjust the conductivity to 2.05-2.75 s / m.

[0043] Preferably, the equilibrium solution of the DEAE-Sepharose FF chromatography column in step S3 is 0.05 mol / L glycine-sodium hydroxide buffer.

[0044] Preferably, step S4 comprises adjusting the pH of the flow-through liquid to 3.8-4.0 with 1 mol / L HCl, concentrating it to 5% by ultrafiltration, continuously dialyzing it with 5 volumes of 4° C. water for injection, adjusting the protein content to 5%, adding maltose, and adjusting the pH with 1 mol / L HCl to make the maltose content 10%, the pH 3.8-4.4, and the protein content %, to obtain a prepared protein solution.

[0045] Preferably, step S5 includes filtering the prepared protein solution through a 0.2 μm sterilizing filter element, placing it in an incubation room, and incubating it at 24°C±1°C for 21 days; after the incubation, filtering the virus with a 20nm nano-membrane filter element, filtering and packaging with a 0.2 μm sterilizing filter element, and sending the packaged products for inspection and light inspection, and packaging and storage after passing the inspection.

[0046] The beneficial effects of the present invention are:

[0047] The preparation process provided by the present invention comprises: dissolving the component II + III precipitate with a precipitate dissolving solution containing 0.8%-1.2% sodium dihydrogen phosphate and 0.66%-1.0% sodium citrate, adding low-temperature ethanol, adding a filter-aid mixed powder for filter pressing, wherein the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4-5:2-3:1-1.5. The human immunoglobulin preparation for intravenous injection prepared by the present invention has an anti-complement activity of only 5%-7%, has good thermal stability, and a purity of up to 99.3%-100%. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0049] The preparation method of the basic solution used in the present invention is as follows:

[0050] 1. pH 4.0 acetate buffer: Take 65.6g of anhydrous sodium acetate, add 244.9mL of glacial acetic acid, fully dissolve with appropriate amount of water for injection, add water for injection to make up to 1L and mix well;

[0051] 2. 0.05 mol / L glycine-sodium hydroxide buffer: Take 250 mL of 0.2 mol / L glycine and 20 mL of 0.2 mol / L NaOH, dilute to 1 L with water for injection, pH 8.6.

[0052] Example 1

[0053] 1. Preparation of precipitation solution and filter-aid mixed powder

[0054] Preparation of precipitation dissolving solution: The precipitation dissolving solution contains 0.9% sodium dihydrogen phosphate and 0.74% sodium citrate. The preparation method of the precipitation dissolving solution is to dissolve sodium dihydrogen phosphate and sodium citrate in water for injection, stir evenly, and add 1 mol / L HCl to adjust the pH to 5.0-5.5.

[0055] Filter aid mixed powder: Mix diatomaceous earth, cellulose and silicon dioxide in a weight ratio of 4.5:2.5:1.

[0056] 2. Preparation method of intravenous human immunoglobulin

[0057] Raw plasma collection and inspection shall be carried out strictly in accordance with the provisions of "Human Plasma for Blood Product Production" in Part III of the 2020 edition of the "Chinese Pharmacopoeia" and the requirements of the "Technical Guidelines for Implementing the Quarantine Management of Raw Plasma".

[0058] (1) Soak the raw plasma in 75% alcohol for 2-3 minutes, then rinse the surface with water for injection, and then break the bag of raw plasma and transfer it to the melting tank, and use 10-37℃ water for interlayer circulation melting. After melting, stop the circulation, control the plasma temperature between 0-4℃, centrifuge and separate the cold precipitate, and transfer the plasma after removing the cold precipitate to the reaction tank for extraction and separation;

[0059] (2) The plasma temperature was controlled between 0 and 4°C, and an acetate buffer solution of pH 4.0 was added to adjust the pH to 6.8-7.2. 95% ethanol at -15°C was added to make the volume ratio of ethanol to plasma 10%. The flow rate of ethanol addition was 1 L / min, and the final temperature of the reaction solution was controlled between -1 and -3°C. After the addition of ethanol, the mixture was centrifuged continuously at 10,000 rpm, and the supernatant was collected to obtain the supernatant of component I.

[0060] (3) Using an acetate buffer solution of pH 4.0, the pH of the supernatant of component I was adjusted to 6.8-7.0, and 95% ethanol at -15°C was added to make the volume ratio of ethanol to the supernatant of component I 20%. The flow rate of adding ethanol was 1.5 L / min, and the final temperature of the reaction solution was controlled at -4 to -6°C. After stirring for 30 minutes, the mixture was allowed to stand for 60 minutes and filtered to obtain component II + III precipitate and component II + III supernatant;

[0061] (4) Add the precipitate dissolving solution to the precipitate of components II + III in a ratio of 1:10 (w / v) of component II + III precipitate: precipitate dissolving solution, start stirring, control the temperature at 0-3°C, slowly add pH 4.0 acetic acid buffer solution to the reaction solution at a flow rate of 0.5 L / min during stirring, adjust the pH of the reaction solution to 5.0-5.3, control the temperature of the reaction solution to 0-1°C, stop stirring when the precipitate is completely dissolved, and obtain a dissolving solution;

[0062] (5) Add 95% ethanol at -15°C to the dissolved solution, control the flow rate to 1.5 L / min, and make the final ethanol volume ratio concentration of the reaction solution 17%; the final temperature of the reaction solution is controlled at -4 to -6°C, continue stirring for 2 hours after adding ethanol, and let it stand for 4 hours for compression filtration; add 12 g of filter-aid mixed powder per liter of reaction solution, stir for 10 minutes, and then perform pressure filtration and deep filtration, collect the supernatant, and obtain the filtered supernatant;

[0063] (6) Filter the supernatant and adjust the pH to 3.8-4 with 1 mol / L HCl, perform ultrafiltration and concentrate to 5%, and dialyze continuously with 5 volumes of 4°C water for injection to adjust the protein content to 5% to obtain a dialysate; adjust the pH of the dialysate to 6.4-6.6 with 0.05 mol / L glycine-sodium hydroxide buffer, add 5% sodium chloride solution to adjust the conductivity of the dissolved solution to 2.05 s / m, and obtain a chromatographic protein solution;

[0064] (7) Equilibrate the DEAE-Sepharose FF column with 3-5 column volumes of 0.05 mol / L glycine-sodium hydroxide buffer, load the column with the protein solution at a linear flow rate of 200 cm / h, collect the flow-through, and perform further processing;

[0065] (8) The flow-through liquid was adjusted to pH 3.8-4.0 with 1 mol / L HCl, concentrated to 5% by ultrafiltration, and dialyzed continuously with 5 volumes of 4°C water for injection. The protein content was adjusted to 5%. Maltose was added, and the pH was adjusted with 1 mol / L HCl to a maltose content of 10%, a pH of 3.8-4.4, and a protein content of 5%, thereby obtaining the prepared protein solution.

[0066] (9) The prepared protein solution is filtered through a 0.2μm sterilizing filter cartridge, placed in an incubation room, and incubated at 24℃±1℃ for 21 days. After the incubation, the virus is filtered through a 20nm nano-membrane, and the solution is filtered and packaged through a 0.2μm sterilizing filter cartridge. The packaged products are sent for inspection and light inspection. After passing the inspection, they are packaged and put into storage.

[0067] Example 2

[0068] 1. Preparation of precipitation solution and filter-aid mixed powder

[0069] Preparation of precipitation dissolving solution: The precipitation dissolving solution contains 1.2% sodium dihydrogen phosphate and 1.0% sodium citrate. The preparation method of the precipitation dissolving solution is to dissolve sodium dihydrogen phosphate and sodium citrate in water for injection, stir evenly, and add 1mol / L HCl to adjust the pH to 5.0-5.5.

[0070] Filter aid mixed powder: Mix diatomaceous earth, cellulose and silicon dioxide in a weight ratio of 4:2:1.

[0071] 2. Preparation method of intravenous human immunoglobulin

[0072] Raw plasma collection and inspection shall be carried out strictly in accordance with the provisions of "Human Plasma for Blood Product Production" in Part III of the 2020 edition of the "Chinese Pharmacopoeia" and the requirements of the "Technical Guidelines for Implementing the Quarantine Management of Raw Plasma".

[0073] (1) Soak the raw plasma in 75% alcohol for 2-3 minutes, then rinse the surface with water for injection, and then break the bag of raw plasma and transfer it to the melting tank, and use 10-37℃ water for interlayer circulation melting. After melting, stop the circulation, control the plasma temperature between 0-4℃, centrifuge and separate the cold precipitate, and transfer the plasma after removing the cold precipitate to the reaction tank for extraction and separation;

[0074] (2) The plasma temperature was controlled between 0 and 4°C, and an acetate buffer solution of pH 4.0 was added to adjust the pH to 6.8-7.2. 95% ethanol at -15°C was added to make the volume ratio of ethanol to plasma 10%. The flow rate of ethanol addition was 1 L / min, and the final temperature of the reaction solution was controlled between -1 and -3°C. After the addition of ethanol, the mixture was centrifuged continuously at 10,000 rpm, and the supernatant was collected to obtain the supernatant of component I.

[0075] (3) Using an acetic acid buffer solution of pH 4.0, the pH of the supernatant of component I was adjusted to 6.8-7.0, and 95% ethanol at -15°C was added to make the volume ratio of ethanol to the supernatant of component I 20%. The flow rate of adding ethanol was 1.5 L / min, and the final temperature of the reaction solution was controlled at -4 to -6°C. After stirring for 30 minutes, the mixture was allowed to stand for 60 minutes and filtered to obtain component II + III precipitate and component II + III supernatant;

[0076] (4) Add the precipitate dissolving solution to the precipitate of components II + III in a ratio of 1:15 (w / v) of component II + III precipitate: precipitate dissolving solution, start stirring, control the temperature at 0-3°C, slowly add pH 4.0 acetic acid buffer solution to the reaction solution at a flow rate of 0.5 L / min during stirring, adjust the pH of the reaction solution to 5.0-5.3, control the temperature of the reaction solution to 0-1°C, stop stirring when the precipitate is completely dissolved, and obtain a dissolving solution;

[0077] (5) Add 95% ethanol at -15°C to the dissolved solution, control the flow rate to 1.5 L / min, and make the final ethanol volume ratio concentration of the reaction solution 17%; the final temperature of the reaction solution is controlled at -4 to -6°C, continue stirring for 2 hours after adding ethanol, and let it stand for 4 hours for compression filtration; add 15 g of filter-aid mixed powder per liter of reaction solution and stir for 10 minutes, then perform pressure filtration and deep filtration, collect the supernatant, and obtain the filtered supernatant;

[0078] (6) Filter the supernatant and adjust the pH to 3.8-4.0 with 1 mol / L HCl, perform ultrafiltration and concentrate to 5%, and continuously dialyze with 5 volumes of 4°C water for injection to adjust the protein content to 5% to obtain a dialysate; adjust the pH of the dialysate to 6.4-6.6 with 0.05 mol / L glycine-sodium hydroxide buffer, add 5% sodium chloride solution to adjust the conductivity of the dissolved solution to 2.75 s / m, and obtain a chromatographic protein solution;

[0079] (7) Equilibrate the DEAE-Sepharose FF column with 3-5 column volumes of 0.05 mol / L glycine-sodium hydroxide buffer, load the column with the protein solution at a linear flow rate of 200 cm / h, collect the flow-through, and perform further processing;

[0080] (8) The flow-through liquid was adjusted to pH 3.8-4 with 1 mol / L HCl, concentrated to 5% by ultrafiltration, and dialyzed continuously with 5 volumes of 4°C water for injection. The protein content was adjusted to 5%. Maltose was added, and the pH was adjusted with 1 mol / L HCl to a maltose content of 11%, a pH of 3.8-4.4, and a protein content of 5%, thereby obtaining the prepared protein solution.

[0081] (9) The prepared protein solution is filtered through a 0.2μm sterilizing filter cartridge, placed in an incubation room, and incubated at 24℃±1℃ for 21 days. After the incubation, the virus is filtered through a 20nm nano-membrane filter cartridge, and then filtered and packaged through a 0.2μm sterilizing filter cartridge. The packaged products are sent for inspection and light inspection, and packaged and stored after passing the inspection.

[0082] Example 3

[0083] The difference between Example 3 and Example 1 is that the preparation methods of the precipitation dissolving solution and the filter-aid mixed powder are different.

[0084] Preparation of precipitation dissolving solution: The precipitation dissolving solution contains 0.8% sodium dihydrogen phosphate and 0.67% sodium citrate. The preparation method of the precipitation dissolving solution is to dissolve sodium dihydrogen phosphate and sodium citrate in water for injection, stir evenly, and add 1 mol / L HCl to adjust the pH to 5.0-5.5.

[0085] Filter aid mixed powder: Mix diatomaceous earth, cellulose and silicon dioxide in a weight ratio of 5:3:1.5.

[0086] Comparative Examples 1-6

[0087] Comparative Examples 1-6 are set with reference to Example 1. The differences between Comparative Examples 1-6 and Example 1 are shown in Table 1:

[0088] Table 1 Differences between Comparative Examples 1-6 and Example 1

[0089]

[0090] Experimental Example 1

[0091] The pH, purity, anti-complement activity and thermal stability of Examples 1-3 and Comparative Examples 1-6 were measured. The measurement method is as follows:

[0092] pH determination: refer to General Chapter 0631 of the 2020 edition of the Chinese Pharmacopoeia.

[0093] Purity determination: refer to the second method of general chapter 0541 of the 2020 edition of the Chinese Pharmacopoeia.

[0094] Anti-complement activity determination: refer to General Chapter 3410 of the 2020 edition of the Chinese Pharmacopoeia.

[0095] Thermal stability determination: After the test sample is kept in a water bath at 57℃±0.5℃ for 4 or 8 hours, it should be observed with naked eyes using a visible foreign matter inspection device to find no gelation or floccules.

[0096] The test results of Examples 1-3 and Comparative Examples 1-6 are shown in Table 2:

[0097] Table 2 Test results of Examples 1-3 and Comparative Examples 1-6

[0098]

[0099] The above detailed description is a specific description of one of the feasible embodiments of the present invention, and the embodiment is not intended to limit the scope of the present invention. It should be pointed out that any equivalent implementation or change that does not deviate from the present invention should be included in the scope of the technical solution of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached requirements.

Claims

1. A process for preparing a human immunoglobulin preparation for intravenous injection, characterized in that: The preparation process comprises: S1. The fraction II + III of human plasma is dissolved with a precipitation dissolving solution, and after adding low-temperature ethanol, pressure filtration and deep filtration are performed; S2, collecting the filtered supernatant, ultrafiltration and dialyzing to obtain dialysate; S3, after adjusting the pH and conductivity of the dialysate, a DEAE-Sepharose FF chromatography column was performed; S4, collecting the flow-through liquid, dialyzing after ultrafiltration, adding maltose as a protective agent, and obtaining a protein solution; S5. After the protein solution is incubated, it is filtered and packaged to obtain a human immunoglobulin preparation for intravenous injection; The step S1 wherein the component II + III precipitate is dissolved with a precipitate dissolving solution comprises: adding the component II + III precipitate to the precipitate dissolving solution, starting stirring, controlling the temperature at 0-3° C., adding a pH 4.0 acetate buffer solution to the reaction solution at a flow rate of 0.5 L / min during stirring, adjusting the pH of the reaction solution to 5.0-5.3, controlling the temperature of the reaction solution to 0 to 1° C., and stopping stirring until the precipitate is completely dissolved to obtain a dissolving solution; The precipitate dissolving solution described in step S1 is composed of 0.8%-1.2% sodium dihydrogen phosphate, 0.66%-1.0% sodium citrate and the remainder of water for injection; the ratio of the component II + III precipitate to the precipitate dissolving solution is 1:10-15 w / v; The step S1 of adding low-temperature ethanol and then performing filter pressing and deep filtration comprises: adding low-temperature ethanol to the dissolved solution, controlling the flow rate to 1.5 L / min, so that the final ethanol volume ratio concentration of the reaction solution is 17%; controlling the final temperature of the reaction solution at -4 to -6°C, continuing to stir for 2 hours after adding ethanol, and standing for 4 hours for compression filtration; adding 12-15 g of the filter-aid mixed powder per liter of the reaction solution, stirring for 10 minutes, and then performing filter pressing and deep filtration, collecting the supernatant to obtain a filtered supernatant; The low-temperature ethanol is 95% ethanol at -15°C; the filter-aid mixed powder is a mixture of diatomaceous earth, cellulose and silicon dioxide; the weight ratio of diatomaceous earth, cellulose and silicon dioxide in the filter-aid mixed powder is 4-5:2-3:1-1.5; The pH value in step S3 is adjusted to 6.4-6.6 by using 0.05 mol / L glycine-sodium hydroxide buffer.

2. The preparation process according to claim 1, characterized in that: The concentration ratio of sodium dihydrogen phosphate to sodium citrate in the precipitation dissolving solution described in step S1 is 1.2:

1.

3. The preparation process according to claim 1, characterized in that: The equilibrium solution of the DEAE-Sepharose FF chromatography column described in step S3 is 0.05 mol / L glycine-sodium hydroxide buffer.

4. The preparation process according to claim 1, characterized in that: In step S3, the conductivity is adjusted to 2.05-2.75 s / m using 5% sodium chloride solution.

Images