CN1644184A - Medicinal coating production for vascular stand and electrostatic spraying apparatus - Google Patents

Abstract

A drug coating preparation method for a vascular stent in the field of medical devices and an electrostatic spraying device thereof, comprising: a vascular stent and a drug coating, characterized in that the preparation steps are: the first step is cleaning and drying; the second step is to mix the drug with the polymer Carrier materials are mixed into paint with a mass ratio of 1:1 to 1:100; the third step is grounding of the vascular stent, and the paint is pressurized by a high-pressure pump at 0.4 to 7 MPa and atomized to form mist droplets, which are discharged by an electrostatic generator Electric charge, charged droplets are adsorbed on the surface of the vascular stent under the combined action of the electric field and high-voltage thrust; the fourth step is to dry and sterilize and package; electrostatic spraying device, features: the power source is connected to the high-pressure pump through the switching valve, and the suction of the high-pressure pump The material valve is connected with the paint container, the discharge valve of the high-pressure pump passes through the pressure accumulation filter and the paint delivery pipe to the nozzle of the spray gun, and the nozzle is connected with the electrostatic generator with a voltage of 1-60kv through a cable. Advantages: uniform surface coating; controllable thickness; high utilization rate of coating; high efficiency of coating preparation.

Description

Preparation method of drug coating for vascular stent and electrostatic spraying device thereof

technical field

The present invention relates to a drug coating preparation method for a vascular stent and an electrostatic spraying device thereof, more precisely, an efficient drug coating method for preparing a vascular stent by electrostatic spraying and an electrostatic spraying device thereof, belonging to medical devices field.

Background technique

In 1987, Sigwart (Sigwart U, et al. Intravascular stents to preventocclusion and restenosis after transluminal angioplasty. N Engl J Med, 1987, 316: 701) etc. implanted coronary artery stents into the human body for the first time, providing a great deal for the treatment of coronary heart disease. good way. However, in-stent restenosis caused by vascular stent implantation largely limits its curative effect. The cause of restenosis is that blood vessels are damaged after being expanded by stents, which induces excessive proliferation of vascular smooth muscle cells and migrates to the intima, resulting in vascular restenosis. Cardiovascular pharmacology studies have found that a variety of drugs can produce significant inhibitory effects on vascular intima and smooth muscle cells in vitro, but the effect of systemic drugs is not good. The reason may be related to the low blood drug concentration in the systemic circulation. The delivery of effective drugs to vascular injuries through drug-coated stents will be beneficial to the treatment of complications.

At present, drug-coated vascular stents have been used clinically at home and abroad. For example, U.S. Pat. No. 6,099,562, U.S. Pat. No. 5,879,697, U.S. Pat. No. 5,092,877 and U.S. Pat. No. 5,304,121 and the like.

The drug coating preparation methods of vascular stents mainly fall into two categories: dip coating and spray coating. Spraying is widely used due to its remarkable advantages—high efficiency and controllable amount of coating. However, due to the fine mesh structure of the vascular stent, the traditional spraying technology usually has dead angles that cannot be sprayed, making it difficult to coat the inner and outer surfaces of the vascular stent uniformly, such as U.S. Pat. Nos. The surface coating is thinner than the outer surface coating. In addition, the paint utilization rate of the traditional spraying method is very low. In fact, only 5% of the paint solution is sprayed on the surface of the bracket in the traditional spraying method, and most of the rest is wasted.

Another spraying technique is electrostatic spraying. The traditional electrostatic spraying method is to ground the surface of the medical device, and the compressed air flows through the nozzle of the spray gun at a high flow rate to form a partial vacuum around the nozzle. When the paint is sucked up by the compressed air flow and sprayed into the vacuum space , is atomized by high-speed airflow to form mist droplets, which are charged after passing through the spraying device connected to the high-voltage power supply. The nozzle of the spraying device and the surface of the grounded support form an electrostatic field, and the charged mist droplets are deposited on the medical instrument surface. For example, U.S. Pat. Nos, 5,824,049 and 6,096,070 describe the preparation of bioactive materials on the surface of medical devices by electrostatic spraying. The disadvantage of this traditional electrostatic spraying technology is that the pressure of the gas is difficult to control, and it is inevitable to lose a large amount of paint in order to obtain a uniform coating on the surface of the medical device. An improved electrostatic spraying method (Method forspray-coating medical devices) mentioned in U.S.Pat.No. 6,669,980 also grounds the surface of the medical device, but the atomization of the coating is completed by pure static electricity. That is, the paint is subjected to the action of a high-voltage electrostatic field, and the paint droplets are split into fine mist droplets. The higher the applied voltage, the stronger the cracking effect of the electric field, and the better the effect of electrostatic atomization. The disadvantages of this method are: ①The coating is purely electrostatically atomized, it is difficult to achieve complete atomization of the coating, and the atomization rate of the coating is low; ②Due to the electrostatic repulsion between the droplets, only a thin layer can be formed on the surface of the stent. layer, it is difficult to meet the requirements of the thickness of the drug coating; ③The formation of the coating depends entirely on electrostatic adsorption, and the speed at which the mist reaches the surface of the vascular stent is extremely slow, which reduces the efficiency of coating preparation.

Therefore, there is a need for a drug coating preparation method for vascular stents, the method makes the surface coating of vascular stents uniform, the thickness can be controlled and can meet the requirements, the coating utilization rate is high, and the coating preparation efficiency is high.

Contents of the invention

Purpose and task of the present invention are to overcome prior art existence: 1. coating atomization rate is low; 2. coating thickness does not meet requirement; The technical solution of the present invention is specially proposed for the drug coating preparation method and electrostatic spraying device of the blood vessel stent that meet the use requirements, have high atomization rate and utilization rate of the coating, and have high coating preparation efficiency.

The technical idea of the present invention is to use a high-pressure pump to increase the pressure of the paint, the pressurized paint is sprayed out from the nozzle rapidly, the pressure is reduced instantaneously, the violent expansion is atomized into very fine mist droplets, and the electrostatic generator is discharged to be charged. , under the combined action of electric field attraction and high-voltage thrust, it is adsorbed on the surface of the vascular stent.

The invention provides a method for preparing a drug coating of a vascular stent, mainly comprising: a vascular stent [2] and a coating [5] mixed with a polymer carrier material and its solvent and a drug, and a drug coating prepared by an electrostatic spraying method, Its polymer carrier materials are polylactide (PLA), polycaprolactone (PCL), poly(lactide-glycolide) (PLGA), poly(lactide-caprolactone) (PGA) or poly (Lactide-glycolide-caprolactone) (PGLC) random or block copolymer; solvents include chloroform, methylene chloride, acetone, tetrahydrofuran, and dioxane; drugs include rapamycin, paclitaxel , heparin, cyclosporin A, dactinomycin, dexamethasone, anti-platelet receptors, traditional Chinese medicine anti-proliferation, anti-coagulant drugs, characterized in that: during electrostatic spraying, the high-pressure pump [7] is also used for coating [5 ] apply pressurized pressure relief spraying, the pressure is 0.4 ~ 7MPa; the steps of coating preparation are:

The first step, cleaning of vascular stent

Place the self-expandable vascular stent or the balloon-expandable vascular stent in acetone, ethanol and distilled water for ultrasonic vibration cleaning for 15-20 minutes; dry in a vacuum drying oven at 60-80°C for 20-30 minutes;

The second step, the preparation of paint

At room temperature, the polymer carrier material and its solvent are mixed and dissolved to form a uniform solution with a concentration range of 1% to 15%, and then the drug is dissolved in the above solution to prepare a coating. The mass ratio of the drug to the polymer carrier material is 1:1 ~1:100;

The third step, the preparation of the drug coating

One or more vascular stents are used in series, the distance between vascular stents is 2-5cm, and then grounded by wires to become electrically neutral; inject the prepared paint into the paint container of the electrostatic spraying device [4], and the paint container [6] and The high-pressure pump [7] is connected, and the high-pressure pump pressurizes the paint, and the pressurized paint is sent to the nozzle [10] of the spray gun through the paint delivery pipe [8], and the paint is sprayed out rapidly from the nozzle connected to the electrostatic generator. Step down, violently expand and atomize into very fine mist droplets [13], and be charged by the discharge of the electrostatic generator, forming an electrostatic field between the nozzle and the vascular stent, the distance between the two is 1-20cm, and the charged paint Under the joint action of electric field attraction and high-voltage thrust, it is adsorbed on the inner and outer surfaces of the stent and forms a uniform coating. The spraying time is 5-30 seconds, and the thickness of the coating is 1-100 μm;

The fourth step, drug coating drying and disinfection

After the drug coating of the stent is prepared, it is placed in a vacuum drying oven, dried at 30-40° C. for 48 hours, sterilized with ethylene oxide, and packaged.

The present invention provides a method for preparing a drug coating for vascular stents, which is further characterized in that: the drugs in the coating [5] are used in combination of one or more.

The present invention provides an electrostatic spraying device for a drug coating preparation method of a vascular stent, mainly comprising: a spray gun [9], a nozzle [10], a paint container [6], an electrostatic generator [11] and a cable [12]. It is characterized in that: in the electrostatic spraying device [4], there is also a high-pressure pump [7] that works through a power source [14], and its spray gun [9] is connected to the paint container [6] through a high-pressure pump [7], The suction valve [21] of the high-pressure pump is connected to the paint container, and the discharge valve [20] of the high-pressure pump passes through the pressure accumulation filter [23] and then passes through the paint delivery pipe [8] to the nozzle [10] of the spray gun. The nozzle is connected with an electrostatic generator [11] with a voltage of 1-60kv through a cable [12].

The present invention provides an electrostatic spraying device for a drug coating preparation method of a vascular stent, which is further characterized in that: the power source [14] of the high-pressure pump adopts a compressed air source, or an oil pressure source, or a power supply, and the pressure of the power source is 0.4 ~7MPa; the power source of the high-pressure pump sends power to the high-pressure pump through the switching valve [15], drives the high-pressure pump piston [18], and pushes the plunger [19] to apply pressure increase and release pressure changes to the paint [5] .

When implementing the technical scheme of the present invention, the parameters adopted should be determined according to the following principles: when the size of the cerebrovascular stent is less, the thickness of the drug coating is thinner, and the coating thickness should take the lower limit, and the concentration of the polymer carrier material, the drug The mass ratio to the polymer carrier material, the pressure of the high-pressure pump, the voltage of the electrostatic generator, the distance between the nozzle and the stent, and the spraying time all take the lower limit; when the size of the peripheral vascular stent is large, the thickness of the drug coating is relatively thick , the coating thickness should take the upper limit, and the polymer carrier material concentration, the mass ratio of the drug to the polymer carrier material, the high pressure pump pressure, the voltage of the electrostatic generator, the distance between the nozzle and the bracket and the spraying time all go to the upper limit; When the size of the coronary artery stent is between the above-mentioned two, the thickness of the coating is also between the above-mentioned two, and other technical parameters are provided according to the intermediate value of the present invention; in order to realize the functionalization of the vascular stent, multiple options can be selected. layer coating.

The main advantages of the present invention are: ① charged fine droplets are deposited on the surface of the vascular stent under the action of an electrostatic field, so that the coating is uniform, and the thickness of the coating can be controlled to 1-100 μm, which has met the requirements for use; ② paint mist The atomization of the paint is not done purely by static electricity, but through the joint action of the high-pressure pump and static electricity to completely atomize the paint, and the atomization rate of the paint can be as high as 100%. 5% of the present invention is increased to 70% of the present invention, and the utilization rate of coating has improved; 3. under the joint effect of high-voltage thrust and electrostatic attraction, droplet has increased the rate that is deposited on support surface, finishes the time of each support coating preparation From 240 to 360 seconds of pure electrostatic adsorption to 5 to 30 seconds of the present invention, the working efficiency is greatly improved.

Description of drawings

Below in conjunction with accompanying drawing, the details of the present invention will be further described:

Fig. 1 is the drug coating surface topography diagram of the vascular stent obtained by the present invention

The photo in the figure is a sine wave tube network type coronary artery stent, after coating the drug coating by the method of the present invention, magnify 100 times with SZX-12 Olympus stereoscopic microscope, the observed vascular stent drug coating [1] local Surface topography.

The figure also shows that the surface coating of the stent [1] is smooth and uniform.

Fig. 2 adopts the schematic diagram of the overall structure state in the pressurization process of the electrostatic spraying device proposed by the present invention

The electrostatic spraying device [4] includes: a high-pressure pump [7], a paint delivery pipe [8], a spray gun [9], a nozzle [10], an electrostatic generator [11] and a cable [12].

The figure shows that the vascular stent [2] is electrically neutral through the wire [3]; the paint [5] is contained in the paint container [6], and the paint container [6] is connected to the spray gun [9] through the high-pressure pump [7] , the paint [5] is pressurized by the high-pressure pump [7] and reaches the nozzle [10] of the spray gun [9] through the paint delivery pipe [8], and the nozzle [10] is connected to the electrostatic generator [11] through the cable [12] .

Also shown in the figure, the power sent by the power source [14] passes through the switching valve [15], the switching valve A port [16] enters, and the switching valve B port [17] exits, so that the piston [18] is lowered, and the plunger [19] is pushed. ] drops, at this time, the suction valve [21] of the high-pressure pump is closed, and the discharge valve [20] of the high-pressure pump is opened. 22] output, through the pressure accumulator filter [23] and the paint delivery pipe [8] to the nozzle [10] of the spray gun [9], it is sprayed out rapidly, the pressure is reduced instantaneously and expanded and atomized into very fine mist droplets [13]. And it is charged by the discharge of the electrostatic generator [11], and is adsorbed on the inner and outer surfaces of the vascular stent [2]. Thin arrows indicate the movement direction of power when the power source [14] acts to lower the piston; thick arrows indicate the movement direction of the plunger [19] pressurizing the paint [5] under the push of the piston; After pressure, the discharge valve [20] of the high-pressure pump is jacked up, and the paint enters the pressure accumulation filter [23] through the high-pressure paint outlet [22], and then enters the direction of the spray gun [9] through the paint delivery pipe [8], the dotted line The structure in the box represents the electrostatic spraying setup [4].

Figure 3 is a schematic diagram of the overall structural state in Figure 2 during the pressure relief process

As shown in the figure, the power sent by the power source [14] passes through the switching valve [15], the switching valve B port [17] enters, and the switching valve A port [16] exits, so that the piston [18] rises and drives the plunger [19] At this time, the suction valve [21] of the high-pressure pump is opened, the discharge valve [20] of the high-pressure pump is closed, and the paint [5] in the paint container [6] enters the high-pressure pump from the suction valve [21] of the high-pressure pump. pump [7], at this time, the discharge valve [20] of the high-pressure pump is closed, and no paint enters the pressure accumulation filter [23] through the high-pressure paint outlet [22], and then enters the spray gun [9] through the paint delivery pipe [8] , that is, no droplets are formed. The thin line arrow indicates the movement direction of the power when the power source [14] acts to make the piston rise; the thick line arrow indicates the upward pressure relief movement direction of the plunger [19] driven by the piston; the dotted line arrow indicates the paint in the paint container [5] Enter the direction of the high-pressure pump through the suction valve [21] of the high-pressure pump.

Fig. 4 is the cross-sectional schematic view of coating multi-layer drug coating on vascular stent by adopting the present invention

As shown in the figure, the vascular stent [2], the inner surface of the vascular stent [25], the outer surface of the vascular stent [24], the coating containing rapamycin [26] and the coating containing heparin [27] are the In order to realize the functionalization of the vascular stent, a specific embodiment of coating a multi-layer drug coating.

Detailed ways

According to the needs of clinical lesions, determine the drug content of the stent, and then determine the ratio of drug and carrier and the thickness of the coating.

Example 1

In order to meet the clinical needs of XX Hospital, and to prepare small-sized drug-coated vascular stents, the technical solution of the present invention is adopted, and the preparation steps are as follows: the first step is to place the vascular stents in acetone, ethanol and distilled water for ultrasonic vibration cleaning for 15 minutes , dried in a vacuum oven at 80°C for 20 minutes; the second step is to prepare the coating, the ratio of the drug to the polymer carrier is 1:1 (mass ratio), and the concentration of the polymer carrier in its solvent is 1%, wherein the drug For paclitaxel, the polymer carrier is poly(lactide-glycolide) (PLGA) and solvent is chloroform; the preparation of the third step drug coating, high pressure pump pressure is 0.4MPa, and the voltage of electrostatic generator is 1kv , the distance between the nozzle and the stent is 1cm. After the paint is atomized, the charged droplets are deposited on the surface of the stent under the joint action of high-voltage thrust and electrostatic attraction. The spraying time is 5 seconds; the fourth step is to dry and sterilize the blood vessel with drug coating After the stent coating is prepared, it is dried in a vacuum drying oven at 30° C. for 48 hours to remove the solvent. After the drug coating is dried, it is sterilized and packaged with ethylene oxide. According to JEOL JSM-5600LV scanning electron microscope, the thickness of the coating is 1.04 μm, and the coating is uniform.

Example 2

The drug-eluting vascular stents prepared in Dalian ×× Hospital for animal experiments are as follows: the first step is to select 32 316L stainless steel balloon-expandable vascular stents (3.0×20cm), and place the vascular stents in acetone , ethanol and distilled water for 20 minutes, and dried in a vacuum oven at 70°C for 25 minutes; the second step is to prepare the coating, the ratio of drug to polymer carrier is 1:10 (mass ratio), and the polymer carrier is in the The concentration in the solvent is 5%, wherein the drug is rapamycin, the polymer carrier is poly(lactide-glycolide) (PLGA) and the solvent is tetrahydrofuran; the preparation of the third step drug coating, 32 The vascular stents are divided into two batches, with a batch of 16. In each batch, the distance between each vascular stent in series is 2cm, the pressure of the high-pressure pump is 1MPa, the voltage of the electrostatic generator is 25kv, and the distance between the nozzle and the stent is 10cm. After the paint is atomized, Charged droplets are deposited on the surface of the stent under the joint action of high-voltage thrust and electrostatic attraction, and the spraying time is 10 seconds; the fourth step is to dry and sterilize the drug coating. Dry at ℃ for 48 hours and remove the solvent; the fifth step is to preload the prepared drug-eluting stent on the balloon delivery system, sterilize it with ethylene oxide and package it; the sixth step is to scan the electron through JEOL JSM-5600LV The coating thickness was 10.06 μm observed under a microscope, and the drug-eluting vascular stent prepared according to the present invention was tested by animal experiments to be qualified products.

Example 3

For the treatment of peripheral vascular lesions, a NiTi shape memory alloy self-expanding vascular stent was selected, and a total of 10 preparation steps were as follows: the NiTi shape memory alloy self-expanding vascular stent was placed in acetone, ethanol and distilled water for ultrasonic vibration cleaning for 20 minutes. Dry at 60°C for 30 minutes in a drying oven; the second step is to prepare the coating, the ratio of the drug to the polymer carrier is 1:100 (mass ratio), the concentration of the polymer carrier in its solvent is 15%, and the drug is Rapa Enzyme, polymer carrier are polylactide (PLA) and solvent are dichloromethane; The preparation of the 3rd step drug coating, 10 vascular stents are connected in series and the distance is 5cm, the high pressure pump pressure is 7MPa, the voltage of electrostatic generator It is 60kv, and the distance between the nozzle and the bracket is 20cm. After the paint is atomized, the charged droplets are deposited on the surface of the bracket under the combined action of high-voltage thrust and electrostatic attraction. The spraying time is 30 seconds; the fourth step is to dry the drug coating and After the sterilized stent coating is prepared, dry it in a vacuum drying oven at 40°C for 48 hours to remove the solvent; the fifth step is to sterilize the prepared drug-eluting stent with ethylene oxide at high temperature and package it, and pass it through JEOL JSM -5600LV scanning electron microscope observation coating thickness of 99μm is confirmed as a qualified product.

Example 4

In order to realize the functionalization of the vascular stent, a two-layer drug-eluting vascular stent was prepared according to the present invention. The preparation steps are as follows: the first step is to select a 316L stainless steel balloon-expanded vascular stent, and place the vascular stent in acetone, ethanol and distilled water respectively. Ultrasonic vibration cleaning for 20 minutes, drying in a vacuum drying oven at 80°C for 20 minutes; the second step is to prepare coatings, two coatings are prepared, the first: the ratio of drug to polymer carrier is 1:50 (mass ratio), The concentration of the polymer carrier in its solvent is 10%, wherein the drug is rapamycin, the polymer carrier is poly(lactide-glycolide) (PLGA) and the solvent is dioxane, the second: The ratio of the drug to the polymer carrier is 1:50 (mass ratio), and the concentration of the polymer carrier in its solvent is 10%, wherein the drug is heparin, and the polymer carrier is poly(lactide-glycolide) (PLGA ) and the solvent are dioxane; the preparation of the third step drug coating, first prepare the coating containing rapamycin on the vascular stent, the high pressure pump pressure is 5MPa, the voltage of the electrostatic generator is 40kv, the nozzle and the stent The distance is 15cm. After the paint is atomized, the charged droplets are deposited on the surface of the bracket under the joint action of high-voltage thrust and electrostatic attraction. The spraying time is 20 seconds, and then a layer of heparin-containing paint is sprayed. The process parameters are the same as above. Obtain a layer of uniform coating [27] on the surface of the coating [26]; the fourth step is to dry the drug coating and sterilize the vascular stent coating, dry it in a vacuum drying oven at 40°C for 48 hours, and remove the solvent; In the fifth step, the prepared drug-eluting stent is pre-installed on the balloon delivery system, sterilized with ethylene oxide and packaged; in the sixth step, the inner and outer layers are observed by JEOL JSM-5600LV scanning electron microscope, and the inner layer The thickness was 49.04 μm, and the thickness of the outer layer was 50.01 μm. Afterwards, it was sent to Beijing XX Hospital for inspection.

Claims (4)

1. A drug coating preparation method for a vascular stent, mainly comprising: a vascular stent [2] and a coating [5] mixed by a polymer carrier material and its solvent and medicine, and a drug coating prepared by an electrostatic spraying method, which Polymer carrier materials are polylactide (PLA), polycaprolactone (PCL), poly(lactide-glycolide) (PLGA), poly(lactide-caprolactone) (PGA) or poly( Lactide-glycolide-caprolactone) (PGLC) random or block copolymers; solvents include chloroform, dichloromethane, acetone, tetrahydrofuran, and dioxane; drugs include rapamycin, paclitaxel, Heparin, cyclosporin A, dactinomycin, dexamethasone, platelet receptor antagonists, traditional Chinese medicine anti-proliferation, anticoagulant drugs, characterized in that: a) During electrostatic spraying, pressurized pressure relief spraying is also applied to the coating [5] through the high-pressure pump [7], and the pressure is 0.4-7MPa; b), the steps of coating preparation are: The first step, cleaning of vascular stent Place the self-expandable vascular stent or the balloon-expandable vascular stent in acetone, ethanol and distilled water for ultrasonic vibration cleaning for 15-20 minutes; dry in a vacuum drying oven at 60-80°C for 20-30 minutes; The second step, the preparation of paint At room temperature, the polymer carrier material and its solvent are mixed and dissolved to form a uniform solution with a concentration range of 1% to 15%, and then the drug is dissolved in the above solution to prepare a coating. The mass ratio of the drug to the polymer carrier material is 1:1 ~1:100; The third step, the preparation of the drug coating One or more vascular stents are used in series, the distance between vascular stents is 2-5cm, and then grounded by wires to become electrically neutral; inject the prepared paint into the paint container of the electrostatic spraying device [4], and the paint container [6] and The high-pressure pump [7] is connected, and the high-pressure pump pressurizes the paint, and the pressurized paint is sent to the nozzle [10] of the spray gun through the paint delivery pipe [8], and the paint is sprayed out rapidly from the nozzle connected to the electrostatic generator. Step down, violently expand and atomize into very fine mist droplets [13], and be charged by the discharge of the electrostatic generator, forming an electrostatic field between the nozzle and the vascular stent, the distance between the two is 1-20cm, and the charged paint Under the joint action of electric field attraction and high-voltage thrust, it is adsorbed on the inner and outer surfaces of the stent and forms a uniform coating. The spraying time is 5-30 seconds, and the thickness of the coating is 1-100 μm; The fourth step, drug coating drying and disinfection After the drug coating of the stent is prepared, it is placed in a vacuum drying oven, dried at 30-40° C. for 48 hours, sterilized with ethylene oxide, and packaged. 2. The method for preparing a drug coating for a vascular stent according to claim 1, wherein the drug in the coating [5] is used in combination of one or more. 3. An electrostatic spraying device for the drug coating preparation method of vascular stents, mainly including: spray gun [9], nozzle [10], paint container [6], electrostatic generator [11] and cable [12]. Because: in the electrostatic spraying device [4], there is also a high-pressure pump [7] that works through the power source [14], and its spray gun [9] is connected to the paint container [6] through the high-pressure pump [7]. The suction valve [21] of the pump is connected to the paint container, while the discharge valve [20] of the high-pressure pump passes through the pressure accumulation filter [23] and then passes through the paint delivery pipe [8] to the nozzle [10] of the spray gun. Connect with the electrostatic generator [11] whose voltage is 1～60kv through the cable [12]. 4. The electrostatic spraying device of a drug coating preparation method for vascular stents according to claim 3, characterized in that: the power source [14] of the high-pressure pump adopts a compressed air source, or an oil pressure source, or a power supply, power The pressure of the source is 0.4-7MPa; the power source of the high-pressure pump sends power to the high-pressure pump through the switching valve [15], drives the high-pressure pump piston [18], and pushes the plunger [19] to apply paint [5]. Increase and decrease pressure conversion.

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