Water-based enteric resin medicine multi-dosage form adaptive efficient coating pan

Abstract

The invention relates to the field of medicine preparation equipment, discloses a multi-dosage-form adaptive efficient coating pan for water-based enteric-coated resin medicines, and aims to solve the problems of poor coating uniformity and low drying efficiency of existing related equipment. The coating pan comprises an airtight tank, a rotary coating pan is arranged in the tank, and spiral stirring blades are arranged on the inner wall of the rotary coating pan; a diaphragm vacuum pump and a servo motor are mounted at the bottom of the tank, the servo motor can drive the rotary coating pan to rotate and the diaphragm vacuum pump to operate to form a negative pressure environment, a metal feeding pipe penetrates through a sealing cover at the top of the tank, a coating material pipe and a hot air pipe are integrated in the metal feeding pipe, and a double-channel electromagnetic valve and an air heating tank are externally connected; a coating material injection pipe and a hot air injection pipe are symmetrically arranged on the side edge of the metal feeding pipe, fan-shaped nozzles are arranged at the tail ends, and a stirring rod is further arranged at the lower end of the metal feeding pipe; the equipment is suitable for various medicine dosage forms, can improve the coating uniformity and the drying efficiency, and has the advantage of energy conservation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pharmaceutical equipment, in particular to a water-soluble enteric resin drug multi-dosage form adaptive high-efficiency coating pan. BACKGROUND

[0002] In the production of pharmaceutical preparations, especially when coating drugs, the uniformity, efficiency and adaptability to different dosage forms of the coating are key indicators to measure the performance of the coating equipment. Traditional drug coating equipment, such as rotary pan coater or fluidized bed coater, often faces some problems when processing water-soluble enteric resin drugs.

[0003] The existing coating pan has deficiencies in the synergistic effect of vacuum degree and hot air. Some equipment only emphasizes high-temperature rapid drying, but ignores the promotion effect of vacuum environment on water evaporation rate and the influence of uniform distribution of hot air on drying effect. After the coating liquid is sprayed, if the water vapor cannot be quickly and uniformly removed, a high-humidity environment may be formed in the local area, which may further cause defects in the coating layer. In addition, the mixing and turning effect of the tablets, granules or pellets in the equipment is not good, which further limits the uniformity and drying efficiency of the coating, for example, some equipment simply relies on the rotation of the pan body, but lacks effective stirring structure inside, so that the drugs in the lower layer cannot be fully contacted with the coating material and hot air, resulting in uneven coating. SUMMARY

[0004] The technical problem to be solved by the present application is that the existing water-soluble enteric resin drug coating equipment has the disadvantages of poor coating uniformity and low drying efficiency. Therefore, the present application provides a water-soluble enteric resin drug multi-dosage form adaptive high-efficiency coating pan.

[0005] To achieve the above purpose, the following technical scheme is adopted in the present application: a water-soluble enteric resin drug multi-dosage form adaptive high-efficiency coating pan, comprising: a gas-tight tank, which is a cylindrical sealed cavity, and the inner wall thereof is provided with a corrosion-resistant coating; a rotary coating pan is rotationally connected in the gas-tight tank through a bearing assembly, and the sidewall of the pan body of the rotary coating pan is provided with dense micropores with a pore size of 0.1-1mm and a porosity of 30%-50%; a diaphragm vacuum pump is fixedly installed at the bottom center of the gas-tight tank, and the suction end of the diaphragm vacuum pump is in sealed communication with the inside of the gas-tight tank; a servo motor is fixedly connected to the bottom of the diaphragm vacuum pump through a flange, the drive shaft of the servo motor extends along the axial direction and is drivingly connected to a connecting main shaft through a shaft coupling, the connecting main shaft penetrates the central shaft hole of the diaphragm vacuum pump and is fixedly connected to the bottom center of the rotary coating pan, and a mechanical seal is arranged between the connecting main shaft and the shaft hole of the diaphragm vacuum pump; The top opening of the airtight container is detachably connected to a sealing cap via a sealing ring. A metal feed pipe runs vertically through the center of the sealing cap, and the metal feed pipe is welded to and sealed to the sealing cap. A coating material pipe and a hot air pipe are arranged axially side-by-side inside the metal feed pipe. The input ends of both the coating material pipe and the hot air pipe extend outside the sealing cap and are connected to a dual-channel solenoid valve. The input end of the hot air pipe is sealed to the air outlet of the air heating tank via a pipe. At least three coating material injection pipes are radially fixedly connected to one side of the metal feed pipe inside the airtight container, and their input and output ends are sealed to each other. At least three hot air injection pipes are radially fixedly connected to the other side of the metal feed pipe, and their input and output ends are sealed to each other. At least two stirring rods are symmetrically fixedly connected to the lower end of the metal feed pipe inside the airtight container.

[0006] Furthermore, the rotary coating pan is an inverted cone with a cone angle of 60°-120°; spiral stirring blades are uniformly fixedly connected to the inner wall of the rotary coating pan along the generatrix direction, and the spiral direction of the spiral stirring blades is adapted to the rotation direction of the rotary coating pan.

[0007] Furthermore, the diaphragm vacuum pump has four independent working chambers evenly distributed circumferentially. Each working chamber is equipped with a one-way suction valve at the top, and the diaphragm vacuum pump is connected to the inside of the airtight tank through the one-way suction valve. Each working chamber is equipped with a one-way exhaust valve at the bottom, which is connected to the outside atmosphere. An elastic diaphragm is sealed inside the working chamber. The elastic diaphragm is made of aging-resistant rubber. An eccentric shaft is fixedly connected to the end of the output shaft of the servo motor. Four sets of push-pull linkages are rotatably connected to the eccentric part of the eccentric shaft through bearings. The other end of each set of push-pull linkages is rotatably connected to the center position of the elastic diaphragm in the corresponding working chamber.

[0008] Furthermore, both the coating material pipe and the hot air pipe pass through the interior of the metal feed pipe along its axial direction, and the two are arranged in parallel; thermally conductive silicone grease is provided between the coating material pipe and the hot air pipe and the inner wall of the metal feed pipe.

[0009] Furthermore, the coating tube, hot air tube, and metal feed tube are all made of copper, and the inner wall of the coating tube is coated with a polytetrafluoroethylene non-stick coating.

[0010] Furthermore, the dual-channel solenoid valve includes two independent solenoid control valve bodies, which are respectively connected to the input ends of the coating material pipe and the hot air pipe, and independently control the feed flow rate of the coating material pipe and the air intake of the hot air pipe, with a control accuracy of ±5%.

[0011] Furthermore, the air heating tank includes a double-layered insulated tank body. The inner layer of the insulated tank body is made of stainless steel, and the outer layer is an insulation material layer. One end of the insulated tank body is provided with an air inlet, and an air inlet filter screen is fixedly installed at the air inlet. The air inlet filter screen is a HEPA-grade filter screen. The other end of the insulated tank body is provided with an air outlet, which is sealed and connected to a hot air pipe through a pipeline. Spiral heating wires are evenly distributed in the airflow direction inside the insulated tank body. The power of the heating wires is adjustable, and the heating temperature range is 30-80℃.

[0012] Furthermore, the coating material injection pipes are perpendicular to the axis of the metal feed pipe and are spaced apart along the axial direction of the metal feed pipe; four coating material injection pipes are provided, with the length decreasing sequentially from top to bottom, and the length difference between adjacent pipes being 5-10 mm; each coating material injection pipe has a fan-shaped nozzle at its end, with the nozzle spraying angle being 45°-60°, and the shortest distance from the outlet end of all nozzles to the inner wall of the rotating coating pan is consistent, being 10-30 mm.

[0013] Furthermore, the hot air jet pipes are perpendicular to the axis of the metal feed pipe and are spaced apart along the axial direction of the metal feed pipe; four hot air jet pipes are provided, with the length decreasing sequentially from top to bottom, and the length difference between adjacent pipes is 5-10 mm; each hot air jet pipe has a fan-shaped nozzle at its end, with a nozzle orifice diameter of 2-5 mm, and the shortest distance from the outlet end of all nozzles to the inner wall of the rotating coating pan is consistent, which is 10-30 mm.

[0014] Furthermore, the coating material spray pipe and the hot air spray pipe are symmetrically arranged on the front and rear sides of the metal feed pipe along its axis, and their spraying directions are opposite; stirring rods are symmetrically arranged on the left and right sides of the metal feed pipe, and a gap of 5-15mm is left between the rotation trajectory of the stirring rods and the inner wall of the rotating coating pan.

[0015] The technical effects and advantages of this invention are as follows: 1. This invention utilizes the centrifugal force of a rotating coating pan to evenly disperse and spread the drug chips on the conical inner wall. Combined with the microporous design of the pan, this facilitates the adhesion of the coating material and the uniform penetration of hot air. Furthermore, the inclusion of spiral stirring blades and a fixed stirring rod effectively mixes the drug, preventing accumulation and adhesion, and ensuring the uniformity of coating for different dosage forms, especially small-sized drugs such as microcapsules. Simultaneously, the symmetrical and staggered arrangement of the coating material spray pipes and hot air spray pipes, along with the fan-shaped design of the nozzles, ensures that the coating material and hot air can comprehensively and evenly cover the drug surface, avoiding dead zones.

[0016] 2. This invention uses a diaphragm vacuum pump to create a vacuum inside the airtight container, forming a negative pressure environment that significantly lowers the boiling point of water, accelerates the evaporation rate of moisture in the coating material, and improves drying efficiency. At the same time, the air heating tank provides precisely temperature-controlled hot air, which, together with the hot air jet pipe, directly heats and dries the drug coating, and allows the hot air to penetrate the drug layer, quickly carrying away water vapor, thereby achieving highly efficient drying.

[0017] 3. This invention integrates a coating material pipe and a hot air pipe within the metal feed pipe, and uses thermally conductive silicone grease for heat transfer. This allows the hot air to preheat the coating material, helping to maintain the temperature stability of the coating material, preventing nozzle clogging, and improving the spraying effect. Simultaneously, a dual-channel solenoid valve integrates the control of the coating material and hot air, simplifying the pipeline layout. Furthermore, vacuum drying technology lowers the temperature required for drying, and the use of an insulated container reduces heat loss. The preheating of the coating material within the coating material pipe by the hot air also utilizes thermal energy, improving overall energy efficiency. Attached Figure Description

[0018] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of the external structure of the present invention; Figure 2 This is a schematic diagram of the opening structure of the sealing cap of the present invention; Figure 3 This is a cross-sectional view of the present invention. Figure 1 ; Figure 4 This is a cross-sectional view of the present invention. Figure 2 ; Figure 5 This is a schematic diagram of the metal feed tube structure of the present invention; Figure 6 This is a cross-sectional view of the air heating tank of the present invention; Figure 7 For the present invention Figure 4 Enlarged structural diagram at point A in the middle; Figure 8 This is a cross-sectional view of the metal feed tube of the present invention.

[0019] Legend: 1. Airtight container; 2. Rotary coating pan; 3. Spiral stirring blade; 4. Diaphragm vacuum pump; 401. Working chamber; 402. One-way suction valve; 403. One-way exhaust valve; 404. Elastic diaphragm; 405. Eccentric shaft; 406. Push-pull connecting rod; 5. Servo motor; 6. Connecting spindle; 7. Sealing cover; 8. Metal feed pipe; 9. Coating material pipe; 10. Hot air pipe; 11. Dual-channel solenoid valve; 12. Air heating tank; 1201. Insulated tank body; 1202. Air inlet filter; 1203. Air outlet; 1204. Heating wire; 13. Coating material injection pipe; 14. Hot air injection pipe; 15. Stirring rod. Detailed Implementation

[0020] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] Example 1, please refer to Figure 1 - Figure 8 This invention provides a high-efficiency coating pan adapted to multiple dosage forms of water-based enteric resin drugs, which mainly includes an airtight tank 1, a rotary coating pan 2, a diaphragm vacuum pump 4, a servo motor 5, a connecting spindle 6, a sealing cover 7, a metal feed pipe 8, a coating material pipe 9, a hot air pipe 10, a dual-channel solenoid valve 11, an air heating tank 12, a coating material spray pipe 13, a hot air spray pipe 14, and a stirring rod 15.

[0022] Among them, the airtight container 1 is a conical sealed cavity with a corrosion-resistant coating on its inner wall to prevent chemical substances from corroding the inside of the container during the coating process, ensuring the service life of the equipment and the purity of the drug. This conical sealed cavity provides a stable low-pressure or even vacuum environment.

[0023] Inside the airtight container 1, a rotating coating pan 2 is rotatably connected via a bearing assembly. The rotating coating pan 2 is the core component for holding drugs for coating treatment. Its side wall has dense micropores with a pore size of 0.1 to 1 mm and a porosity of 30% to 50%. This range of pore size and porosity design allows hot air to penetrate the drug layer evenly inside the pan and effectively remove water vapor generated during the coating process, while preventing drug particles from escaping from the micropores.

[0024] A diaphragm vacuum pump 4 is fixedly installed at the bottom center of the airtight container 1. The pumping end of the diaphragm vacuum pump 4 is sealed and connected to the inside of the airtight container 1, and is responsible for extracting the air from the airtight container 1 to form a negative pressure environment, thereby accelerating the evaporation of moisture. A servo motor 5 is fixedly connected to the bottom of the diaphragm vacuum pump 4 through a flange. The drive shaft of the servo motor 5 extends axially and is connected to the connecting main shaft 6 through a coupling. The connecting main shaft 6 passes through the central shaft hole of the diaphragm vacuum pump 4 and is fixedly connected to the bottom center of the rotating coating pan 2. The servo motor 5 drives the connecting main shaft 6, thereby driving the rotating coating pan 2 to rotate. In order to ensure the airtightness of the airtight container 1, a mechanical seal is provided between the connecting main shaft 6 and the shaft hole of the diaphragm vacuum pump 4 to effectively prevent external air from entering and maintain the vacuum state inside the container.

[0025] The top opening of the airtight container 1 is detachably connected to a sealing cover 7 via a sealing ring. This detachable design facilitates the cleaning and maintenance of the inside of the airtight container 1, as well as the loading and unloading of drugs. A metal feed pipe 8 is vertically inserted through the center of the sealing cover 7. The metal feed pipe 8 is fixed and sealed to the sealing cover 7 by welding, ensuring the sealing performance and structural stability.

[0026] Inside the metal feed pipe 8, a coating material pipe 9 and a hot air pipe 10 are arranged side-by-side along the axial direction. The coating material pipe 9 is used to transport the coating liquid, and the hot air pipe 10 is used to transport drying hot air. The input ends of both the coating material pipe 9 and the hot air pipe 10 extend outside the sealing cover 7 and are connected to a dual-channel solenoid valve 11. The dual-channel solenoid valve 11 is used to independently control the flow rate of the coating material and the hot air. The input end of the hot air pipe 10 is sealed and connected to the air outlet of the air heating tank 12 through a pipe. The air heating tank 12 is used to filter and heat the incoming hot air.

[0027] The metal feed pipe 8 is located on one side of the inner wall of the airtight container 1, and at least three coating material spray pipes 13 are fixedly connected radially. The input end of these coating material spray pipes 13 is sealed and connected to the output end of the coating material pipe 9, and is responsible for spraying the coating material evenly onto the surface of the drug in the rotating coating pan 2. On the other side of the metal feed pipe 8, at least three hot air spray pipes 14 are fixedly connected radially. The input end of these hot air spray pipes 14 is sealed and connected to the output end of the hot air pipe 10, and is used to spray heated hot air onto the drug to accelerate drying.

[0028] To further improve the uniformity of drug mixing, the metal feed pipe 8 is located at the lower end inside the airtight container 1, and at least two stirring rods 15 are symmetrically fixedly connected to it. These stirring rods 15 remain relatively stationary when the rotating coating pan 2 rotates, and generate relative motion with the rotating drug, thereby effectively stirring the drug, preventing agglomeration and adhesion, and ensuring the uniformity of coating.

[0029] When using the aforementioned coating pan, first pour the drug chip into the rotary coating pan 2, then cover it with the sealing cap 7, and connect the coating material tube 9 to the container holding the coating material. After preparation, start the servo motor 5 to drive the rotary coating pan 2 to rotate. When the rotary coating pan 2 rotates, the centrifugal force causes the drug chip to be evenly dispersed on the conical inner wall of the rotary coating pan 2. At the same time, the servo motor 5 also drives the diaphragm vacuum pump 4 to extract the air from the airtight container 1, so that the air pressure in the airtight container 1 is lower than the external atmospheric pressure, forming a vacuum. At this time, the dual-channel solenoid valve 11 opens the coating pan. The connection between the coating tube 9 and the hot air tube 10 allows the external atmospheric pressure to push the coating material from the coating tube 9 into the metal feed tube 8, and then evenly spray it out from the coating material spray tube 13 to cover the surface of the drug chip. At the same time, outside air is also drawn in, filtered and heated by the air heating tank 12, and then sprayed out from the hot air spray tube 14 opposite to the coating material spray tube 13 to heat and dry the drug coating. Meanwhile, the spiral stirring blade 3 rotates with the rotating coating pan 2, and works with the stationary stirring rod 15 to stir the drug, making it more uniform. Then, the hot air carrying steam enters the airtight tank 1 through the micropores on the rotating coating pan 2, and is then extracted by the diaphragm vacuum pump 4. The conical shape and micropores of the rotating coating pan 2 allow the drug to be evenly dispersed and spread out when the rotating coating pan 2 rotates, which is beneficial for coating adhesion and drying. After the hot air is blown out, it passes through the pores between the drug chips and flows out through the micropores on the rotating coating pan 2, making the drying effect more thorough and uniform.

[0030] Example 2, based on Example 1, further optimizes the structure and stirring effect of the rotary coating pan 2.

[0031] Please see Figure 3 and Figure 4 The rotating coating pan 2 is an inverted cone with a cone angle of 60°-120°. This inverted cone design allows the drug to be better dispersed and rolled during rotation under the combined action of centrifugal force and gravity, avoiding drug accumulation at the bottom or edge of the pan, ensuring the uniformity of coating, and maximizing the coating area while ensuring that the drug is fully rolled.

[0032] More preferably, spiral stirring blades 3 are uniformly fixedly connected to the inner wall of the rotary coating pan 2 along the generatrix direction. The spiral direction of these spiral stirring blades 3 is adapted to the rotation direction of the rotary coating pan 2. When the rotary coating pan 2 rotates, the spiral stirring blades 3 can effectively lift the drug at the bottom of the pan upward and make the drug at the top of the pan descend to the bottom of the pan, thereby achieving full mixing and tumbling in three dimensions. This greatly enhances the relative movement between drug particles, ensuring that each drug can fully contact the coating material and hot air, further improving the uniformity of coating and drying efficiency. This active stirring combined with passive centrifugal force dispersion method enables this coating pan to be efficiently adapted to various dosage forms of drugs, including microcapsules and granules that are easy to accumulate.

[0033] Example 3, based on Example 1 or Example 2, further refines the structure of the diaphragm vacuum pump 4, the metal feed pipe 8 and its internal pipelines, and the air heating tank 12.

[0034] Please see Figure 7 The diaphragm vacuum pump 4 has four independent working chambers 401 evenly distributed circumferentially. Each working chamber 401 has a one-way suction valve 402 at its top, connecting the diaphragm vacuum pump 4 to the inside of the airtight tank 1, ensuring only suction and no retraction. Each working chamber 401 also has a one-way exhaust valve 403 at its bottom, connecting to the outside atmosphere to discharge the gas extracted by the vacuum pump. An elastic diaphragm 404 is sealed inside each working chamber 401. The elastic diaphragm 404 is made of aging-resistant rubber, ensuring the diaphragm's sealing performance and lifespan during long-term operation. An eccentric shaft 405 is fixedly connected to the output shaft end of the servo motor 5. Four sets of push-pull connecting rods 406 are rotatably connected to the eccentric part of the eccentric shaft 405 through bearings. The other end of each set of push-pull connecting rods 406 is rotatably connected to the center position of the elastic diaphragm 404 in the corresponding working chamber 401. When the servo motor 5 drives the eccentric shaft 405 to rotate, the push-pull connecting rods 406 drive the four elastic diaphragms 404 to reciprocate, thereby realizing continuous evacuation of the airtight tank 1 and providing a stable vacuum environment. This multi-chamber diaphragm pump has the advantages of simple structure, stable operation, convenient maintenance and no oil pollution.

[0035] Please see Figure 5 and Figure 8Both the coating material pipe 9 and the hot air pipe 10 pass through the interior of the metal feed pipe 8 along its axial direction and are arranged in parallel, so that the coating material and hot air can be transported through the same path, resulting in a compact structure. Thermally conductive silicone grease is provided between the coating material pipe 9 and the hot air pipe 10 and the inner wall of the metal feed pipe 8. This thermally conductive silicone grease can effectively transfer the heat in the hot air pipe 10 to the coating material pipe 9, preheating the coating material. This helps to reduce the viscosity of the coating material, improve its atomization effect, and prevent the coating material from solidifying or clogging the nozzle at low temperatures. Especially when processing water-based enteric resin drugs, maintaining a suitable temperature is crucial for coating quality.

[0036] Furthermore, the coating material pipe 9, the hot air pipe 10, and the metal feed pipe 8 are all made of copper. Copper has excellent thermal conductivity, which can better achieve heat transfer. In addition, the inner wall of the coating material pipe 9 is provided with a polytetrafluoroethylene anti-stick coating. This coating can effectively prevent the coating material from adhering to the pipe wall during the conveying process, ensuring smooth material flow and reducing cleaning difficulty.

[0037] Please see Figure 5 The dual-channel solenoid valve 11 includes two independent solenoid control valve bodies, which are respectively connected to the input ends of the coating material pipe 9 and the hot air pipe 10. It can independently control the feed flow rate of the coating material pipe 9 and the air intake of the hot air pipe 10. Its control accuracy is ±5%, which ensures that the supply of coating material and hot air can be precisely adjusted according to process requirements, and the coating process can be finely managed to obtain high-quality coating film.

[0038] Please see Figure 6 The air heating tank 12 includes a double-layered insulated tank body 1201. The inner layer of the insulated tank body 1201 is made of stainless steel, and the outer layer is an insulation material layer. The stainless steel inner layer ensures the corrosion resistance and cleanliness of the tank body, while the insulation material layer effectively reduces heat loss and improves energy efficiency. An air inlet is provided at one end of the insulated tank body 1201, and an air inlet filter 1202 is fixedly installed at the air inlet. The air inlet filter 1202 is a HEPA-grade filter to ensure that the incoming hot air meets the cleanliness requirements and avoids contamination. The drug causes secondary pollution; the other end of the heat-insulating tank 1201 is provided with an air outlet 1203, which is sealed and connected to the hot air pipe 10 through a pipe; the heat-insulating tank 1201 has a spiral heating wire 1204 evenly distributed along the airflow direction. The power of the heating wire 1204 is adjustable, and the heating temperature range is 30-80℃. It is suitable for the gentle drying of water-based enteric resin drugs, preventing high temperature from damaging the drug activity or coating film structure. At the same time, its adjustable power and spiral distribution ensure uniform heating of the hot air.

[0039] Please see Figure 5The coating material spraying pipes 13 are perpendicular to the axis of the metal feed pipe 8 and are spaced apart along the axial direction of the metal feed pipe 8. There are four coating material spraying pipes 13, with the length decreasing from top to bottom. The length difference between two adjacent pipes is 5-10 mm, which allows the coating material spraying to cover the drug at different heights in the rotating coating pan 2, providing more comprehensive spraying. Each coating material spraying pipe 13 has a fan-shaped nozzle at its end. The nozzle spraying angle is 45°-60°. The fan-shaped nozzle can form a wide and thin atomization surface to achieve uniform coverage of the coating material. The shortest distance from the outlet end of all nozzles to the inner wall of the rotating coating pan 2 is the same, which is 10-30 mm. This ensures that the drug can receive uniform coating material spraying intensity at different positions and avoids uneven coating thickness caused by distance differences.

[0040] Please refer to it again. Figure 5 The hot air jet pipes 14 are perpendicular to the axis of the metal feed pipe 8 and are spaced apart along the axial direction of the metal feed pipe 8. There are four hot air jet pipes 14, with the length decreasing from top to bottom. The length difference between two adjacent pipes is 5-10 mm, which corresponds to the layout of the coating material jet pipes 13 to ensure the coverage of hot air. Each hot air jet pipe 14 has a fan-shaped nozzle at its end. The nozzle orifice diameter is 2-5 mm. The fan-shaped nozzles can form a concentrated hot air flow to effectively dry the drug area after the coating material is sprayed. The shortest distance from the outlet end of all nozzles to the inner wall of the rotating coating pan 2 is the same, which is 10-30 mm, ensuring the uniformity and consistency of hot air drying.

[0041] Please see Figure 5 and Figure 8 The coating material spray pipe 13 and the hot air spray pipe 14 are symmetrically arranged on the front and rear sides of the metal feed pipe 8 along its axis. The two spray directions are opposite, which can form an alternating spraying and drying of the drug, realizing the synergistic process of coating and drying, and avoiding mutual interference between the coating material and the hot air, thus improving the coating efficiency and quality. Stirring rods 15 are symmetrically arranged on the left and right sides of the metal feed pipe 8. The rotation trajectory of the stirring rod 15 leaves a gap of 5-15mm between itself and the inner wall of the rotating coating pan 2. This ensures that the stirring rod 15 can fully agitate the drug, while avoiding friction with the inner wall of the rotating coating pan 2, protecting the equipment and extending its service life. The stirring rod 15 and the spiral stirring blade 3 work together to significantly enhance the mixing effect of the drug and ensure the uniformity of the coating.

[0042] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs, characterized in that, include: An airtight container is a cylindrical sealed cavity with a corrosion-resistant coating on its inner wall. A rotating coating pan is rotatably connected to the airtight container via a bearing assembly. The side wall of the rotating coating pan has dense micropores. A diaphragm vacuum pump is fixedly installed at the center of the bottom of the airtight container, and the pumping end of the diaphragm vacuum pump is in sealed communication with the inside of the airtight container. A servo motor is fixedly connected to the bottom of the diaphragm vacuum pump via a flange. The drive shaft of the servo motor extends axially and is connected to a connecting main shaft via a coupling. The connecting main shaft passes through the central shaft hole of the diaphragm vacuum pump and is fixedly connected to the center of the bottom of the rotating coating pan. The top opening of the airtight container is detachably connected to a sealing cap via a sealing ring. A metal feed pipe vertically penetrates the center of the sealing cap, and the metal feed pipe is welded and sealed to the sealing cap. A coating material pipe and a hot air pipe are arranged axially side-by-side inside the metal feed pipe. The input ends of both the coating material pipe and the hot air pipe extend outside the sealing cap and are connected to a dual-channel solenoid valve. The input end of the hot air pipe is sealed to the air outlet of the air heating tank via a pipe. At least three coating material injection pipes are radially fixedly connected to one side of the metal feed pipe inside the airtight container, and the input and output ends of the coating material injection pipes are sealed to each other. At least three hot air injection pipes are radially fixedly connected to the other side of the metal feed pipe, and the input and output ends of the hot air injection pipes are sealed to each other. At least two stirring rods are symmetrically fixedly connected to the lower end of the metal feed pipe inside the airtight container.

2. The high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs according to claim 1, characterized in that, The rotating coating pan is in the shape of an inverted cone; spiral stirring blades are uniformly fixedly connected to the inner wall of the rotating coating pan along the generatrix direction, and the spiral direction of the spiral stirring blades is adapted to the rotation direction of the rotating coating pan.

3. The high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs according to claim 1, characterized in that, The diaphragm vacuum pump has four independent working chambers evenly distributed circumferentially. Each working chamber is equipped with a one-way suction valve at the top, and the diaphragm vacuum pump is connected to the inside of the airtight tank through the one-way suction valve. Each working chamber is equipped with a one-way exhaust valve at the bottom, and the one-way exhaust valve is connected to the outside atmosphere. An elastic diaphragm made of aging-resistant rubber is sealed inside each working chamber. An eccentric shaft is fixedly connected to the end of the output shaft of the servo motor. Four sets of push-pull linkages are rotatably connected to the eccentric part of the eccentric shaft through bearings. The other end of each set of push-pull linkages is rotatably connected to the center position of the elastic diaphragm in the corresponding working chamber.

4. The high-efficiency coating pan for multi-dosage form adaptation of aqueous enteric resin drugs according to claim 1, characterized in that, Both the coating material pipe and the hot air pipe pass through the interior of the metal feed pipe along its axial direction and are arranged in parallel. Thermally conductive silicone grease is provided between the coating material pipe and the hot air pipe and the inner wall of the metal feed pipe.

5. The high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs according to claim 4, characterized in that, The coating tube, hot air tube, and metal feed tube are all made of copper, and the inner wall of the coating tube is coated with a polytetrafluoroethylene anti-stick coating.

6. The high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs according to claim 1, characterized in that, The dual-channel solenoid valve includes two independent solenoid control valve bodies, which are respectively connected to the input ends of the coating material pipe and the hot air pipe, and independently control the feed flow rate of the coating material pipe and the air intake volume of the hot air pipe.

7. The high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs according to claim 1, characterized in that, The air heating tank includes a double-layered insulated tank body. The inner layer of the insulated tank body is made of stainless steel, and the outer layer is a heat insulation material layer. One end of the insulated tank body is provided with an air inlet, and an air filter screen is fixedly installed at the air inlet. The other end of the insulated tank body is provided with an air outlet, which is sealed and connected to a hot air pipe through a pipeline. Spiral heating wires are evenly distributed in the insulated tank body along the airflow direction.

8. The high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs according to claim 1, characterized in that, The coating material injection pipes are perpendicular to the axis of the metal feed pipe and are spaced apart along the axial direction of the metal feed pipe; there are four coating material injection pipes, with the length decreasing sequentially from top to bottom; each coating material injection pipe has a fan-shaped nozzle at its end, and the shortest distance from the outlet end of all nozzles to the inner wall of the rotating coating pan is the same.

9. The high-efficiency coating pan adapted for multiple dosage forms of aqueous enteric resin drugs according to claim 1, characterized in that, The hot air jet pipes are perpendicular to the axis of the metal feed pipe and are spaced apart along the axial direction of the metal feed pipe; four hot air jet pipes are provided, with their lengths decreasing sequentially from top to bottom; each hot air jet pipe has a fan-shaped nozzle at its end, and the shortest distance from the outlet end of all nozzles to the inner wall of the rotating coating pan is the same.

10. The high-efficiency coating pan for multi-dosage form adaptation of aqueous enteric resin drugs according to claim 1, characterized in that, The coating material spray pipe and the hot air spray pipe are symmetrically arranged on the front and rear sides of the metal feed pipe along its axis, and their spraying directions are opposite; stirring rods are symmetrically arranged on the left and right sides of the metal feed pipe.

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