Preparation method of medicinal crystal powder
By using standstill settler, nitrogen filtration and washing, intermittent nitrogen replacement and drying and flip-off methods in the preparation of drug crystal powder, the problems of complex operation, low yield and poor particle size control in the traditional preparation methods are solved, and high-quality, uniform particle size and high yield drug crystal powder preparation is achieved.
Patent Information
- Application Number
- CN202411780587.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-03-07
AI Technical Summary
The preparation method of traditional drug crystal powders has problems such as high operational complexity, low product yield, insufficient particle size control and poor drying uniformity.
By transferring the drug crystal suspension to a filter washing drying tank, after standing, filtering and washing with nitrogen, controlling the nitrogen pressure between 0.03 and 0.25MPa, drying with intermittent nitrogen replacement, and turning the tank body and purging during discharge to reduce residue.
It realizes high-quality preparation of drug crystal powder, with uniform particle size distribution, small changes in crystal particle size during drying, loose and uncaking of products, high yield, and simple operation of equipment.
Smart Images
Figure BDA0005172684200000071
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of pharmaceuticals, and in particular to a method for preparing a drug crystal powder. Background Art
[0002] In the pharmaceutical industry, the preparation of drugs into crystalline powders is crucial to ensure drug stability, consistency, bioavailability, and adaptability to different formulation processes and routes of administration. The physical properties of crystalline powders directly affect the dissolution rate and efficacy of drugs.
[0003] The preparation of crystalline powder refers to the process of washing and drying the crystal suspension obtained by crystallization into powder. The traditional preparation method has great limitations, including high operational complexity, low product yield, inadequate particle size control and poor drying uniformity, which affect the quality and production efficiency of drug crystal powder. Among them, due to the lack of precise particle size control, the particle size distribution of the obtained powder may be wide, thus affecting the solubility and consistency of the drug; due to the uneven drying of the product, the stability and yield of the drug are affected, limiting the improvement of production efficiency and product quality.
[0004] To this end, a method for preparing a drug crystal powder is now provided. Summary of the invention
[0005] The present invention aims to solve the technical problems of high operational complexity, low product yield, poor particle size control and poor drying uniformity in the traditional preparation method of crystalline powder, and aims to provide a preparation method of drug crystal powder, which can effectively improve the product quality and yield of drug crystal powder, and the product particle size distribution is uniform, the crystal particle size changes little during the drying process, the drug crystal powder obtained after drying is loose and does not agglomerate, and the equipment is simple and easy to operate.
[0006] The present invention is achieved through the following technical solutions:
[0007] A method for preparing a drug crystal powder comprises the following steps:
[0008] Transfer the drug crystal suspension to a filter, wash and dry tank and allow to settle;
[0009] The pressure was controlled at 0.03-0.25 MPa by nitrogen, and the mother liquor was filtered to obtain a crude drug crystal cake;
[0010] The nitrogen gas is passed through to control the pressure at 0.03-0.25 MPa, and the drug crystal coarse filter cake is washed multiple times;
[0011] Pressing and filtering to obtain drug crystal filter cake;
[0012] De-cake the drug crystal filter cake by stirring;
[0013] Heat and evacuate the tank, intermittently introduce nitrogen for replacement, and stop replacing when no water droplets are observed in the tank visually, thus completing pre-drying;
[0014] Keep heating and vacuuming, start stirring, and introduce nitrogen intermittently for 24-60 hours to complete drying;
[0015] Cooling and discharging to obtain drug crystal powder.
[0016] Furthermore, the static sedimentation time is 2-10 minutes.
[0017] Furthermore, the filter pressing process includes: introducing nitrogen into the tank, controlling the pressure at 0.03-0.25 MPa, and filter pressing for 5-30 minutes to obtain a drug crystal filter cake.
[0018] Furthermore, during the pre-drying and drying process, the heating temperature is 70-95° C., and the pressure in the tank is controlled at -0.06 to -0.09 MPa.
[0019] Furthermore, the heating during the pre-drying and drying process refers to: passing hot water into the tank jacket for heating.
[0020] Furthermore, during the pre-drying process, nitrogen is introduced into the tank every hour until the pressure reaches 0.1 MPa for nitrogen replacement.
[0021] Furthermore, during the drying process, nitrogen is introduced into the tank every 5-6 hours until the pressure reaches 0.1 MPa for nitrogen replacement.
[0022] Furthermore, during the drying process, the stirring paddle is stirred at 2 to 6 rpm for 60 seconds every 1 to 2 hours, and is intermittently stirred by rotating clockwise.
[0023] Furthermore, the cooling process includes: stopping vacuuming, passing nitrogen into the tank to restore the pressure to normal, cooling the tank to a temperature of ≤30°C, and completing the cooling of the drug powder crystals.
[0024] Furthermore, the discharging process includes: turning over the tank body, intermittently introducing nitrogen to purge and peel off the drug powder adhering to the tank wall and the stirring paddle, and transferring all of them to the receiving storage tank.
[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0026] 1. In the crystal collection stage, the present invention forms a crystal bond bridge by static sedimentation, effectively preventing the loss of small-size crystals and maintaining the stability of the particle size. In the filtering and washing stages, nitrogen is introduced and the nitrogen pressure is controlled at 0.03-0.25 MPa to protect the integrity of the crystals. By adopting nitrogen cold pressing and controlling the pressure at 0.03-0.25 MPa, the integrity of the crystals can be effectively protected and the consistency of the crystal particle size can be ensured. In the drying stage, intermittent nitrogen replacement is adopted to achieve uniform drying, prevent crystal agglomeration and increase of particle size. At the same time, when discharging, the discharging is turned over and purged, which further reduces the residue and loss of crystals and ensures a high yield.
[0027] 2. The method of the present invention can effectively improve the product quality and yield of drug crystal powder, the product particle size distribution is uniform, the crystal particle size changes little during the drying process, the drug crystal powder obtained after drying is loose and does not agglomerate, and the filtering, washing and drying integrated machine is used, and the equipment operation is simple. DETAILED DESCRIPTION
[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the embodiments. Obviously, the schematic implementation modes of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.
[0029] The following is a detailed description of an embodiment of a method for preparing a pharmaceutical crystal powder of the present invention. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions and repeated descriptions of well-known matters are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art.
[0030] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range.
[0031] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.
[0032] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.
[0033] Unless otherwise specified, the terms "include" and "comprising" mentioned in this application may be open-ended or closed-ended. For example, the terms "include" and "comprising" may mean that other substances not listed may also be included or only the listed substances may be included.
[0034] If there is no special explanation, all the steps of the present application can be performed sequentially or randomly, preferably sequentially.
[0035] In order to solve the problems of high operation complexity, low product yield, imprecise particle size control and uneven drying in the preparation process of drug crystal powder in the prior art, the technical solution of the present invention is to provide a method for preparing drug crystal powder, comprising the following steps:
[0036] (1) Crystal collection: The drug crystal suspension is transferred to a filter, washing and drying tank and allowed to settle for 2-10 minutes. This step uses gravity to promote the settling of drug crystals, forming crystal bond bridges and preventing the loss of small-size crystals. During this process, the stirring paddle in the tank is lowered to the lowest position to avoid destroying the crystal structure.
[0037] (2) Nitrogen filtration: Pass nitrogen into the tank and control the pressure at 0.03-0.25 MPa. Filter the mother liquor into the mother liquor collection tank until there is no continuous water column in the sight glass at the bottom of the tank. A coarse filter cake of drug crystals is obtained and then turn off the nitrogen flow.
[0038] (3) Washing: Use the cleaning liquid and the coarse filter cake to fully stir and mix, let it stand for a period of time, then introduce nitrogen again, control the pressure at 0.03-0.25MPa, filter the cleaning liquid into the cleaning liquid collection tank, and repeat the washing several times until the residual solvent test meets the standard. This step can effectively reduce the residual solvent and improve the washing effect by washing in small amounts and multiple times. At the same time, during the nitrogen filtering and washing process, nitrogen is introduced and the pressure is maintained at 0.03-0.25MPa, which achieves gentle treatment and is beneficial to protecting the integrity of the crystal.
[0039] (4) Filtration: nitrogen is introduced into the tank, the pressure is controlled at 0.03-0.25 MPa, and filtration is performed for 5-30 minutes to obtain a drug crystal filter cake. This step can effectively protect the integrity of the crystals and ensure the consistency of the crystal particle size by using nitrogen cold pressing and controlling the pressure at 0.03-0.25 MPa.
[0040] (5) De-cake: De-cake the drug crystal filter cake by stirring.
[0041] (6) Pre-drying: Pass 70-95°C hot water into the tank jacket for heating, evacuate the tank, and control the pressure in the tank at -0.06 to -0.09 MPa. Pass nitrogen into the tank every hour until the pressure reaches 0.1 MPa for nitrogen replacement. Stop replacement when no water droplets are visible in the tank, and pre-drying is completed.
[0042] (7) Drying: Keep heating and vacuuming, stir with a stirring paddle at 2-6 rpm for 60 seconds every 1-2 hours, rotate clockwise for intermittent stirring, and introduce nitrogen into the tank every 5-6 hours until the pressure reaches 0.1 MPa for nitrogen replacement. Continue for 24-60 hours to complete drying.
[0043] During the pre-drying and drying process, uniform drying is achieved by using intermittent nitrogen replacement, preventing crystal agglomeration and particle size increase.
[0044] (8) Cooling: Stop vacuuming, pass nitrogen into the tank to restore the pressure to normal, pass room temperature water or cold water into the tank jacket to cool the tank to a temperature of ≤30°C, and complete the cooling of the drug powder crystals.
[0045] (9) Discharging: Turn the tank to the discharge port, and introduce nitrogen intermittently to purge the drug powder adhering to the tank wall and the stirring paddle, and transfer all of it to the receiving storage tank to obtain drug crystal powder.
[0046] In the crystal collection stage, the present invention forms a crystal bond bridge by static sedimentation, effectively prevents the loss of small-diameter crystals, and maintains the stability of the particle size. In the filtering and washing stages, nitrogen is introduced and the nitrogen pressure is controlled at 0.03-0.25 MPa to protect the integrity of the crystal. By adopting nitrogen cold pressing and controlling the pressure at 0.03-0.25 MPa, the integrity of the crystal can be effectively protected and the consistency of the crystal particle size can be ensured. In the drying stage, intermittent nitrogen replacement is adopted to achieve uniform drying, prevent crystal agglomeration and increase of particle size. At the same time, when discharging, turning discharging and purging are adopted to further reduce the residue and loss of crystals and ensure a high yield.
[0047] In summary, the method of the present invention can effectively improve the product quality and yield of drug crystal powder, the product particle size distribution is uniform, the crystal particle size changes little during the drying process, the drug crystal powder obtained after drying is loose and does not agglomerate, and the filtering, washing and drying integrated machine is used, and the equipment operation is simple.
[0048] The technical solution of the present invention is further described in detail below in conjunction with embodiments.
[0049] It should be noted that the experimental methods used in the examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained by those skilled in the art through commercial channels.
[0050] Example 1
[0051] Raw materials: brepazine crystal suspension, with an initial particle size distribution of 1-20 μm and a volume average particle size (DV50) of 10 μm.
[0052] Equipment: Filter, wash and dryer. Manufacturer: Shanghai Dongfulong Technology Co., Ltd., Model: PFD650.
[0053] A method for preparing a drug crystal powder comprises the following steps:
[0054] (1) Crystal collection: The drug crystal suspension was transferred to a filtration, washing and drying machine and allowed to stand for 5 minutes to promote the settling of the drug crystals. During this process, the stirring paddle in the tank was lowered to 0 mm to avoid destroying the crystal structure.
[0055] In this embodiment, the drug crystal suspension is 80 kg in total, including 4 kg of raw material input, and the rest is auxiliary materials and solvent. After final washing and drying, the yield is calculated according to the raw material input.
[0056] (2) Nitrogen filtration: Introduce nitrogen into the tank and control the pressure at 0.1 MPa. Filter until there is no continuous water column in the sight glass at the bottom of the tank and a coarse filter cake of drug crystals is obtained. Then turn off the nitrogen flow.
[0057] (3) Washing: Stir the cleaning solution (sterile water for injection) prepared in advance in the washing tank with the coarse filter cake, let it stand for 15 minutes, then introduce nitrogen again, control the pressure at 0.1 MPa, and filter for 15 minutes. Repeat this process more than 3 times until the residual solvent test meets the control standard.
[0058] (4) Filtration: Introduce nitrogen into the tank, control the pressure at 0.1 MPa, and filter for 15 minutes to obtain a drug crystal filter cake.
[0059] (5) De-cake: Turn the tank to a horizontal position slightly downward in the direction of the discharge port (110°), lift the stirring paddle 20 mm, rotate it clockwise at 3 rpm for one circle and then stop. Lower the stirring paddle to 0 mm, rotate it clockwise at 3 rpm for one circle and then stop. De-cake is completed.
[0060] (6) Pre-drying: Heat the tank jacket with 85℃ hot water, start the vacuum system, and control the pressure in the tank at -0.07MPa. About every hour, introduce nitrogen into the tank until the pressure in the tank reaches 0.1MPa for nitrogen replacement. Stop the replacement when there are no water droplets in the tank visually.
[0061] (7) Drying: Keep heating and vacuuming, stir with a stirring paddle at 3 rpm for 60 seconds every 1.5 hours, and rotate clockwise. About every 6 hours, introduce nitrogen into the tank until the pressure inside the tank reaches 0.1 MPa for nitrogen replacement. Continue for 48 hours to complete drying.
[0062] (8) Cooling: Stop vacuuming and pass nitrogen into the tank to restore the pressure to normal. Pass normal temperature water into the tank jacket to displace and cool the tank to a temperature of ≤30°C.
[0063] (9) Discharging: Turn the tank body to about 150 degrees in the direction of the discharge port, and use gravity and a stirring paddle to discharge the material. Introduce nitrogen into the tank for 5-10 seconds every 5 minutes, and control the gas supply pressure to 0.1-0.25 MPa. Blow away the drug powder adhering to the tank wall and the stirring paddle, and transfer all of it to the storage tank to obtain the drug crystal powder.
[0064] Example 2
[0065] Raw materials: brepazine crystal suspension, with an initial particle size distribution of 1-20 μm and a volume average particle size (DV50) of 10 μm.
[0066] Equipment: Filter, wash and dryer all in one.
[0067] A method for preparing a drug crystal powder comprises the following steps:
[0068] (1) Crystal collection: The drug crystal suspension was transferred to a filtration, washing and drying machine and allowed to stand for 10 minutes to promote the settling of the drug crystals. During this process, the stirring paddle in the tank was lowered to 0 mm to avoid destroying the crystal structure.
[0069] (2) Nitrogen filtration: Introduce nitrogen into the tank and control the pressure at 0.25 MPa. Filter until there is no continuous water column in the sight glass at the bottom of the tank and a coarse filter cake of drug crystals is obtained. Then turn off the nitrogen flow.
[0070] (3) Washing: Stir the cleaning liquid prepared in advance in the washing tank and the coarse filter cake thoroughly, let it stand for 30 minutes, then introduce nitrogen again, control the pressure at 0.25 MPa, and filter for 5 minutes. Repeat this process more than 3 times until the residual solvent test meets the control standard.
[0071] (4) Filtration: Introduce nitrogen into the tank, control the pressure at 0.25 MPa, and filter for 5 minutes to obtain a drug crystal filter cake.
[0072] (5) De-cake: Turn the tank to a horizontal position slightly downward in the direction of the discharge port (110°), lift the stirring paddle 20 mm, rotate it clockwise at 3 rpm for one circle and then stop. Lower the stirring paddle to 0 mm, rotate it clockwise at 3 rpm for one circle and then stop. De-cake is completed.
[0073] (6) Pre-drying: Heat the tank jacket with 95°C hot water, start the vacuum system, and control the pressure in the tank at -0.09MPa. About every hour, introduce nitrogen into the tank until the pressure in the tank reaches 0.1MPa for nitrogen replacement. Stop the replacement when there are no water droplets in the tank visually.
[0074] (7) Drying: Keep heating and vacuuming, stir with a stirring paddle at 3 rpm for 60 seconds every 1.5 hours, and rotate clockwise. About every 6 hours, introduce nitrogen into the tank until the pressure inside the tank reaches 0.1 MPa for nitrogen replacement. Continue for 48 hours to complete drying.
[0075] (8) Cooling: Stop vacuuming and pass nitrogen into the tank to restore the pressure to normal. Pass normal temperature water into the tank jacket to displace and cool the tank to a temperature of ≤30°C.
[0076] (9) Discharging: Turn the tank body to about 150 degrees in the direction of the discharge port, and use gravity and a stirring paddle to discharge the material. Introduce nitrogen into the tank for 5-10 seconds every 5 minutes, and control the gas supply pressure to 0.25 MPa to blow away the drug powder adhering to the tank wall and the stirring paddle, and transfer all of it to the storage tank to obtain the drug crystal powder.
[0077] Example 3
[0078] Raw materials: brepazine crystal suspension, with an initial particle size distribution of 1-20 μm and a volume average particle size (DV50) of 10 μm.
[0079] Equipment: Filter, wash and dryer all in one.
[0080] A method for preparing a drug crystal powder comprises the following steps:
[0081] (1) Crystal collection: The drug crystal suspension was transferred to a filtration, washing and drying machine and allowed to stand for 10 minutes to promote the settling of the drug crystals. During this process, the stirring paddle in the tank was lowered to 0 mm to avoid destroying the crystal structure.
[0082] (2) Nitrogen filtration: Introduce nitrogen into the tank and control the pressure at 0.05 MPa. Filter until there is no continuous water column in the sight glass at the bottom of the tank and a coarse filter cake of drug crystals is obtained. Then turn off the nitrogen flow.
[0083] (3) Washing: Stir the cleaning liquid prepared in advance in the washing tank and the coarse filter cake thoroughly. After standing for 30 minutes, introduce nitrogen again, control the pressure at 0.05MPa, and filter for 30 minutes. Repeat this process more than 3 times until the residual solvent test meets the control standard.
[0084] (4) Filtration: Introduce nitrogen into the tank, control the pressure at 0.05 MPa, and filter for 30 minutes to obtain a drug crystal filter cake.
[0085] (5) De-cake: Turn the tank to a horizontal position slightly downward in the direction of the discharge port (110°), lift the stirring paddle 20 mm, rotate it clockwise at 3 rpm for one circle and then stop. Lower the stirring paddle to 0 mm, rotate it clockwise at 3 rpm for one circle and then stop. De-cake is completed.
[0086] (6) Pre-drying: Heat the tank jacket with 70°C hot water, start the vacuum system, and control the pressure in the tank at -0.09MPa. About every hour, introduce nitrogen into the tank until the pressure in the tank reaches 0.1MPa for nitrogen replacement. Stop the replacement when there are no water drops in the tank visually.
[0087] (7) Drying: Keep heating and vacuuming, stir with a stirring paddle at 3 rpm for 60 seconds every 1.5 hours, and rotate clockwise. About every 6 hours, introduce nitrogen into the tank until the pressure inside the tank reaches 0.1 MPa for nitrogen replacement. Continue for 48 hours to complete drying.
[0088] (8) Cooling: Stop vacuuming and pass nitrogen into the tank to restore the pressure to normal. Pass normal temperature water into the tank jacket to displace and cool the tank to a temperature of ≤30°C.
[0089] (9) Discharging: Turn the tank body to about 150 degrees in the direction of the discharge port, and use gravity and a stirring paddle to discharge the material. Introduce nitrogen into the tank for 5-10 seconds every 5 minutes, and control the gas supply pressure to 0.15 MPa to blow away the drug powder adhering to the tank wall and the stirring paddle, and transfer all of it to the storage tank to obtain the drug crystal powder.
[0090] Comparative Example 1
[0091] The difference between this comparative example and Example 1 is that during the nitrogen filtering and washing process, the pressure is controlled at 0.3 MPa, and the rest is the same as Example 1.
[0092] Comparative Example 2
[0093] The difference between this comparative example and Example 1 is that hot nitrogen at 70° C. is passed during the pressure filtration, and the rest is the same as Example 1.
[0094] Comparative Example 3
[0095] The difference between this comparative example and Example 1 is that nitrogen replacement is not introduced during the pre-drying and drying process, and the rest is the same as Example 1.
[0096] The products prepared in Example 1 and Comparative Examples 1-3 were tested, and the results are shown in Table 1.
[0097] Table 1. Test results of products prepared in Example 1 and Comparative Examples 1-3
[0098]
[0099] It can be seen from the data in Table 1 that the method of the present invention successfully prepares a drug crystal powder with high particle size consistency and high yield by accurately controlling key parameters and adopting key means such as nitrogen cold pressing and nitrogen replacement. In contrast, Comparative Examples 1-3 lack precise control and do not adopt means such as nitrogen cold pressing and nitrogen replacement, resulting in poor drying uniformity, difficult particle size control, uneven particle size distribution, low product yield, reduced product yield and product quality, and affected production efficiency.
[0100] Finally, it should be noted that the above specific embodiments are only used to explain in detail the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific implementation method of the present invention and is not used to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the above specific embodiments, ordinary technicians in this field should understand that it is still possible to modify the technical solutions recorded in the above embodiments, or to replace or improve some or all of the technical features therein. These modifications, equivalent replacements and improvements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.
Claims
1. A method for preparing a drug crystal powder, characterized in that: The following steps are involved: Transfer the drug crystal suspension to a filter, wash and dry tank and allow to settle; The pressure was controlled at 0.03-0.25 MPa by nitrogen, and the mother liquor was filtered to obtain a crude drug crystal cake; The nitrogen gas is passed through to control the pressure at 0.03-0.25 MPa, and the drug crystal coarse filter cake is washed multiple times; Pressing and filtering to obtain drug crystal filter cake; De-cake the drug crystal filter cake by stirring; Heat and evacuate the tank, intermittently introduce nitrogen for replacement, and stop replacing when no water droplets are observed in the tank visually, thus completing pre-drying; Keep heating and vacuuming, start stirring, and introduce nitrogen intermittently for 24-60 hours to complete drying; Cooling and discharging to obtain drug crystal powder.
2. The method for preparing a drug crystal powder according to claim 1, characterized in that: The static sedimentation time is 2-10 minutes.
3. The method for preparing a drug crystal powder according to claim 1, characterized in that: The filter pressing process comprises: introducing nitrogen into the tank, controlling the pressure at 0.03-0.25 MPa, and filter pressing for 5-30 minutes to obtain a drug crystal filter cake.
4. The method for preparing a drug crystal powder according to claim 1, characterized in that: During the pre-drying and drying process, the heating temperature is 70-95° C. and the pressure in the tank is controlled at -0.06 to -0.09 MPa.
5. The method for preparing a drug crystal powder according to claim 4, characterized in that: The heating during the pre-drying and drying process refers to: passing hot water into the tank jacket for heating.
6. The method for preparing a drug crystal powder according to claim 1, characterized in that: During the pre-drying process, nitrogen was introduced into the tank every hour until the pressure reached 0.1 MPa for nitrogen replacement.
7. The method for preparing a drug crystal powder according to claim 1, characterized in that: During the drying process, nitrogen was introduced into the tank every 5-6 hours until the pressure reached 0.1 MPa for nitrogen replacement.
8. The method for preparing a drug crystal powder according to claim 1, characterized in that: During the drying process, the stirring paddle is stirred at 2-6 rpm for 60 seconds every 1-2 hours, and is intermittently stirred by rotating clockwise.
9. The method for preparing a drug crystal powder according to claim 1, characterized in that: The cooling process includes: stopping vacuuming, passing nitrogen into the tank to restore the pressure to normal, cooling the tank to a temperature of ≤30°C, and completing the cooling of the drug powder crystals.
10. The method for preparing a drug crystal powder according to claim 1, characterized in that: The discharging process includes: turning over the tank body, intermittently introducing nitrogen to purge and peel off the drug powder adhering to the tank wall and the stirring paddle, and transferring all of them to the receiving storage tank.