CN111298187B

CN111298187B - Method and device for preparing degradable microspheres for embolism treatment

Info

Publication number: CN111298187B
Application number: CN202010104468.0A
Authority: CN
Inventors: 苏红清; 李建; 王栋
Original assignee: Shandong Guyuchun Biotechnology Technology Co ltd
Current assignee: Shandong Mining Medical Technology Co ltd
Priority date: 2020-02-20
Filing date: 2020-02-20
Publication date: 2021-12-10
Anticipated expiration: 2040-02-20
Also published as: CN111298187A

Abstract

The invention belongs to the technical field of medicine preparation, and particularly relates to a method and a device for preparing degradable microspheres for embolism treatment. The invention adopts alcohol as the mobile phase, accelerates the hardening speed of the microsphere surface, does not use water phase, only uses a small amount of mobile phase, does not need to treat sewage, is assisted by a corresponding device, recycles the mobile phase, can be finally recycled, reduces the amount of the mobile phase used for preparing the same amount of microspheres, and is easy for industrial production.

Description

Method and device for preparing degradable microspheres for embolism treatment

Technical Field

The invention belongs to the technical field of medicine preparation, and particularly relates to a method and a device for preparing degradable microspheres for embolism treatment.

Background

The embolism is to inject an embolic agent to block the nutrition blood vessel supplying to the focus, so as to achieve the effect of starving focus cells or changing the flow direction of the blood vessel. Under the guidance of medical imaging equipment, special precise instruments such as catheters, guide wires and the like are introduced into a human body to diagnose and locally treat in-vivo pathological conditions. The main application range of embolization includes hemostasis, treatment of vascular diseases, treatment of blood-rich tumors, organ inactivation, diversion of blood flow, and the like.

In recent years, domestic embolic materials are mainly classified into two categories: one is degradable material, such as iodized oil, sodium alginate microspheres, gelatin sponge and the like, but the embolization time is short, the iodized oil is quickly washed away by blood, and the sodium alginate microspheres and the gelatin sponge lose the effect due to degradation in less than 1 month.

The other is a material which is not degradable in vivo and forms permanent embolism, such as polyvinyl alcohol modifier microspheres, polyvinyl alcohol/sodium acrylate copolymer microspheres, triacrylate gelatin microspheres and the like, but the non-degradable material can cause chronic inflammation after the treatment is completed, and has unpredictable results.

The existing preparation methods of the degradable material microspheres include a solvent evaporation method, a melt extrusion method, a spray drying method, a high-speed homogeneous emulsification method, a coacervation method, a micro-jet method, a micro-pore extrusion method and the like. The process capable of realizing large-scale production only adopts a spray drying method and a high-speed homogeneous emulsification method, but the produced microspheres have large size difference of 0.2-200 mu m and wide microsphere distribution, and are not suitable for serving as an embolic agent. The microspheres prepared by the membrane emulsification method have small particle size distribution, but the particle size is only 50-1000 nm.

Disclosure of Invention

In order to solve the problems, the invention provides a method and a device for preparing degradable microspheres for embolism treatment, wherein the microspheres are Polycaprolactone (PCL) and Polyhydroxyalkanoate (PHA) microspheres which can be degraded in vivo.

The invention relates to a method for preparing degradable microspheres for embolism treatment, which comprises the following steps:

(1) dissolving PCL or PHA in organic solvent to form stationary phase;

(2) the method comprises the steps of extruding a stationary phase into a continuous circulating mobile phase through micropores by adopting pressure, separating the extruded stationary phase from the micropores to form microspheres insoluble in the mobile phase on an interface contacted with the mobile phase under the action of impulsive force of the mobile phase, collecting the microspheres, and recycling the mobile phase.

In the step (1), the organic solvent is dichloromethane or N, N-dimethylformamide or dimethyl sulfoxide or nitrogen-methyl pyrrolidone or ethyl acetate or propyl acetate or tetrahydrofuran or a mixture thereof, which has good solubility to PCL or PHA.

In the step (2), the mobile phase is selected from methanol or ethanol, PCL or PHA is insoluble in the solvent, and the solvent accelerates the hardening speed of the surface of the microsphere, so that the microsphere is not adhered.

In step (2), a surfactant, such as tween 80, sorbitol fatty acid ester, polyethylene glycol or a mixture thereof, is added to the mobile phase. The surfactant is added to promote the diffusion of the solvent for dissolving PCL or PLGA, accelerate the hardening of the microsphere surface and make the microsphere not sticky. The mass percent of the surfactant is 0.01-3.0%, and if the mass percent is too small, the surfactant cannot play a role, and if the mass percent is too large, the microspheres are easy to adhere.

In the step (1), the mass fraction of PCL or PHA in the stationary phase is 30-80%. The microspheres are not easy to form due to too small mass fraction, and the fixed phase is too viscous and easy to block micropores due to too large mass fraction.

In the step (2), the extrusion conditions are that the temperature is 10-35 ℃, the pressure is 0.1-0.8 MPa, the diameter of the micropore is 50-100 mu m, and the flow rate of the mobile phase is 1500-4000 mL/min. The temperature is too low, the solvent is not easy to volatilize, the microspheres are easy to adhere, and the temperature is too high and is close to the glass transition temperature of the microspheres, and the microspheres are easy to adhere. The pressure is too low, the stationary phase can not be extruded out, micropores are easy to block, and the particle size of the extruded microspheres is small due to overlarge pressure. The extruded microspheres with too low flow rate cannot be flushed off to block the microporous tube, and the particle size of the microspheres with too large flow rate is reduced.

In the preparation method, alcohol is used as the mobile phase, so that the hardening speed of the microsphere surface is accelerated, no water phase is used, sewage treatment is not needed, only a small amount of mobile phase is used, the mobile phase is recycled and can be finally recovered, the amount of the mobile phase used for preparing the same amount of microspheres is reduced, and the industrial production is easy.

In order to match the preparation method, the invention also provides a device for preparing the degradable microspheres for embolism treatment, which comprises a stationary phase storage tank, a microsphere forming device and a microsphere collecting device; a stationary phase outlet is arranged on the stationary phase storage tank; the microsphere forming device comprises an inner pipe and an outer pipe, the inner pipe is sleeved in the outer pipe, an annular cavity is formed between the inner pipe and the outer pipe, micropores are formed in the side wall of the inner pipe, a fixed phase inlet communicated with one end of the inner pipe is formed in one end of the inner pipe, and a microsphere outlet and a mobile phase inlet communicated with the annular cavity are formed in the outer pipe; the microsphere collecting device is provided with a microsphere inlet and a mobile phase outlet; the stationary phase outlet is communicated with the stationary phase inlet through a pipeline I, the microsphere outlet is communicated with the microsphere inlet through a pipeline III, and the mobile phase outlet is communicated with the mobile phase inlet through a pipeline II.

During specific production, PCL or PHA is dissolved in an organic solvent to form a stationary phase, the stationary phase is stored in a stationary phase storage tank, pressure is applied to the stationary phase storage tank, the stationary phase enters the inner tube through the pipeline I, and the stationary phase is extruded to the annular cavity from the micropores of the inner tube. At this time, the mobile phase stored in the microsphere forming device enters the annular cavity through the pipeline II, the extruded stationary phase is separated from the micropores to form microspheres insoluble in the mobile phase on an interface contacted with the mobile phase under the action of the impulsive force of the mobile phase, and the microspheres and the mobile phase enter the microsphere collecting device through the pipeline III. The microsphere collecting device is internally provided with a screen, the aperture of the screen is smaller than the diameter of the micropore, and the screen separates the microsphere-containing mobile phase and the microsphere-free mobile phase in the microsphere collecting device into two parts, so that the mobile phase can be recycled without influencing the prepared microspheres. The inner pipe and the outer pipe are preferably made of stainless steel.

And a valve and a pressure gauge are arranged on the pipeline I, so that the control of the pressure and the amount of the stationary phase entering the inner pipe can be realized.

And a valve is arranged on the pipeline II, so that the collection of microspheres and a mobile phase can be realized.

And a pump, a valve and a pressure gauge are arranged on the pipeline III, so that the mobile phase can be adjusted at any time.

Compared with the prior art, the invention has the following beneficial effects:

(1) PCL and PHA are biodegradable materials in vivo, the glass transition temperature is far lower than room temperature, the PCL and PHA are soft and extrusion-resistant in a human body, the original shape is recovered without deformation after the stress disappears, and PCL or PHA microspheres (D50: 100-500 μm) with large particle size are ideal embolization materials;

(2) the invention adopts alcohol as the mobile phase, accelerates the hardening speed of the microsphere surface, does not use water phase, does not need to treat sewage, only uses a small amount of mobile phase, recycles the mobile phase, can be finally recycled, reduces the amount of the mobile phase used for preparing the same amount of microspheres, and is easy for industrial production.

(3) The method has simple process, controls all parameters in the production process, is assisted by a corresponding device, ensures that the finally obtained product has narrow particle size distribution and large microsphere particle size of 100-500 mu m, has good repeatability of products in each batch, and is easy for industrial production.

Drawings

FIG. 1 is a schematic structural diagram of a device for preparing degradable microspheres for embolism therapy according to example 1 of the present invention;

FIG. 2 is a schematic structural diagram of a device for preparing degradable microspheres for embolism therapy according to example 1 of the present invention;

FIG. 3 is a top view of a microsphere formation apparatus according to the present invention;

FIG. 4 is a schematic view of the inner tube structure of the present invention;

in the figure: 1. a stationary phase storage tank 1-1, a stationary phase outlet 1-2, a pressure pipeline 1-3 and a pressure inlet; 2. 2-1 parts of a microsphere forming device, 2-2 parts of an inner pipe, 2-2 parts of an outer pipe, 2-3 parts of an annular cavity, 2-4 parts of micropores, 2-5 parts of a stationary phase inlet, 2-6 parts of a microsphere outlet, 2-7 parts of a mobile phase inlet; 3. 3-1 parts of a microsphere collecting device, 3-2 parts of a microsphere inlet, 3-2 parts of a mobile phase outlet, 3-3 parts of a screen mesh; 4. Pipeline I, 5, pipeline II, 6, pipeline III, 7, valve, 8, pressure gauge, 9, pump, 10, storage area I, 11, storage area II.

FIG. 5 is a microphotograph of microspheres prepared by method example 1;

FIG. 6 is a microphotograph of microspheres prepared by method example 2;

FIG. 7 is a microphotograph of microspheres prepared by method example 3;

FIG. 8 is a microphotograph of microspheres prepared by method example 4;

Detailed Description

Apparatus example 1

A device for preparing degradable microspheres for embolism treatment comprises a stationary phase storage tank 1, a microsphere forming device 2 and a microsphere collecting device 3; a stationary phase outlet 1-1 is arranged on the stationary phase storage tank 1; the microsphere forming device 2 comprises an inner tube 2-1 and an outer tube 2-2, wherein the inner tube 2-1 is sleeved in the outer tube 2-2, an annular cavity 2-3 is formed between the inner tube 2-1 and the outer tube 2-2, micropores 2-4 are formed in the side wall of the inner tube 2-1, one end of the inner tube 2-1 is provided with a stationary phase inlet 2-5 communicated with the inner tube, and the outer tube 2-2 is provided with a microsphere outlet 2-6 and a mobile phase inlet 2-7 communicated with the annular cavity 2-3; the fixed phase inlet 2-5 and the mobile phase inlet 2-7 are arranged at the same end of the microsphere forming device, and the fixed phase inlet 2-5 and the microsphere outlet 2-6 are arranged at two ends of the microsphere forming device; the microsphere collecting device 3 is provided with a microsphere inlet 3-1 and a mobile phase outlet 3-2; the stationary phase outlet 1-1 is communicated with a stationary phase inlet 2-5 through a pipeline I4, the microsphere outlet 2-6 is communicated with a microsphere inlet 3-1 through a pipeline III6, and the mobile phase outlet 3-2 is communicated with a mobile phase inlet 2-7 through a pipeline II 5. The stationary phase storage tank 1 is provided with a pressure pipeline 1-2 and a pressure inlet 1-3.

The microsphere collecting device 3 is internally and vertically provided with a screen 3-3, the screen 3-3 divides the microsphere collecting device 3 into a storage area I10 and a storage area II11 from left to right, a microsphere inlet 3-1 is communicated with the storage area I10, and a mobile phase outlet 3-2 is communicated with the storage area II 11. The aperture of the screen 3-3 is smaller than the diameter of the micropore 2-4; the inner pipe can be detachably connected with the outer pipe by adopting the known technology in the field, the diameter of the micropores 2-4 can be selected from 50-100 mu m according to the production condition, and the particle size is controlled by combining process parameters.

Be equipped with valve 7 and pressure gauge 8 on the pipeline I4, be equipped with valve 7 on the pipeline II5, be equipped with pump 9, valve 7 and pressure gauge 8 on the pipeline III 6.

Apparatus example 2

The microsphere collecting device 3 is internally provided with a screen 3-3, the screen 3-3 divides the microsphere collecting device 3 into an upper storage area I10 and a lower storage area II11, a microsphere inlet 3-1 is communicated with the storage area I10, and a mobile phase outlet 3-2 is communicated with the storage area II 11. The aperture of the screen 3-3 is smaller than the diameter of the micropore 2-4; the inner pipe can be detachably connected with the outer pipe by adopting the known technology in the field, the diameter of the micropores 2-4 can be selected from 50-100 mu m according to the production condition, and the particle size is controlled by combining process parameters.

Method example 1

A method of preparing degradable microspheres for embolization therapy, comprising the steps of:

(1) 100g of Polycaprolactone (PCL) (MW: 77454) is weighed and dissolved in dichloromethane to prepare a stationary phase, and the mass fraction of the PCL in the stationary phase is 40%;

(2) adopting micropore extrusion technology, the diameter of micropore on the inner tube is 50 μm, the mobile phase is ethanol solution (containing 1.5% Tween 80), extruding the fixed phase into the mobile phase of continuous circular flow by 0.33MPa pressure, on the interface contacting with the mobile phase, under the action of impact force of the mobile phase, the extruded fixed phase separates from micropore to form microsphere insoluble in mobile phase, after microsphere is solidified, collecting microsphere, volatilizing organic solvent in vacuum, observing by microscope, microsphere surface is smooth, shape is round, microsphere yield: 74.3 percent.

In the step (2), the extrusion condition is that the temperature is 35 ℃, the diameter of the micropore is 50 microns, the flow rate of the mobile phase is 4000mL/min, and the particle size of the microsphere is 100-500 microns.

Method example 2

(1) weighing 100g of PCL (MW: 33214), dissolving in N, N-dimethylformamide to prepare a stationary phase, wherein the mass fraction of the PCL in the stationary phase is 80%;

(2) adopting micropore extrusion process, using ethyl alcohol solution as mobile phase (containing 0.1% Tween 80 and 1.5% sorbitol fatty acid ester), making micropore diameter on inner tube be 100 micrometers, using 0.27MPa pressure to extrude stationary phase into continuous circulating mobile phase, on the interface contacted with mobile phase, under the action of impulsive force of mobile phase, the extruded stationary phase can be separated from micropore to form microsphere which is insoluble in mobile phase, after the microsphere is solidified, collecting microsphere, vacuum volatilizing organic solvent, and observing by microscope, the microsphere surface is smooth and its form is round, and its microsphere yield is: 77.1 percent.

In the step (2), the extrusion condition is that the temperature is 15 ℃, the diameter of the micropore is 100 microns, the flow rate of the mobile phase is 3000 mL/min, and the particle size of the microsphere is 100-500 microns.

Method example 3

(1) weighing 100g Polycaprolactone (PHA) (homemade, MW: 44201), dissolving in dimethyl sulfoxide to prepare a stationary phase, wherein the mass fraction of the PHA in the stationary phase is 30%;

(2) adopting micropore extrusion process, the diameter of micropore on the inner tube is 100 micrometers, the mobile phase is ethyl alcohol solution (containing 0.2% polyethylene glycol), using 0.38MPa pressure to extrude stationary phase into continuous circulating mobile phase, on the interface contacted with mobile phase, under the action of impulsive force of mobile phase the extruded stationary phase is separated from micropore to form microsphere insoluble in mobile phase, after the microsphere is solidified, collecting microsphere, vacuum volatilizing organic solvent, observing by microscope, the microsphere surface is smooth, form is round, microsphere yield is: 69.9 percent.

In the step (2), the extrusion condition is that the temperature is 20 ℃, the diameter of the micropore is 100 microns, the flow rate of the mobile phase is 1500mL/min, and the particle size of the microsphere is 100-500 microns.

Method example 4

(1) weighing 100g of PHA (self-made MW: 21910), and dissolving the PHA in N-methylpyrrolidone to prepare a stationary phase, wherein the mass fraction of the PHA in the stationary phase is 50%;

(2) adopting a micropore extrusion process, wherein a mobile phase is a methanol solution (containing 1.2 percent of Tween 80), the diameter of micropores on an inner tube is 100 microns, extruding a stationary phase into a continuous circulating mobile phase by using the pressure of 0.30MPa, separating the extruded stationary phase from the micropores to form microspheres which are insoluble in the mobile phase under the action of impulsive force of the mobile phase on an interface contacted with the mobile phase, collecting the microspheres after the microspheres are solidified, volatilizing an organic solvent in vacuum, and observing by a microscope, wherein the microspheres have smooth surfaces, round shapes and high microsphere yield: 71.4 percent.

In the step (2), the extrusion condition is that the temperature is 25 ℃, the diameter of the micropore is 100 microns, the flow rate of the mobile phase is 4000mL/min, and the particle size of the microsphere is 100-500 microns.

Claims

1. A method for preparing degradable microspheres for embolism treatment is characterized by comprising the following steps:

(1) dissolving PCL or PHA in organic solvent to form stationary phase;

(2) extruding the fixed phase into a continuous circulating mobile phase through micropores by adopting pressure, separating the extruded fixed phase from the micropores to form microspheres insoluble in the mobile phase on an interface contacted with the mobile phase under the action of impulsive force of the mobile phase, collecting the microspheres, and recycling the mobile phase;

in the step (2), the mobile phase is selected from methanol or ethanol.

2. The method for preparing degradable microspheres for embolism therapy according to claim 1, wherein in step (1), the organic solvent is dichloromethane or N, N-dimethylformamide or dimethyl sulfoxide or N-methylpyrrolidone or ethyl acetate or propyl acetate or tetrahydrofuran or a mixture thereof.

3. The method for preparing degradable microspheres for embolism treatment according to claim 1, wherein in the step (2), a surfactant is added into the mobile phase, and the mass percent of the surfactant is 0.01-3.0%.

4. The method for preparing degradable microspheres for embolism treatment according to claim 1, wherein in step (1), the mass fraction of PCL or PHA in the stationary phase is 30-80%.

5. The method for preparing degradable microspheres for embolism treatment according to claim 1, wherein in step (2), the extrusion conditions are 10-35 ℃ of temperature, 0.1-0.8 MPa of pressure, 50-100 μm of micropore diameter, 1500-4000 mL/min of flow rate of mobile phase, and the particle size of the microspheres is 100-500 μm.

6. The method for preparing degradable microspheres for embolism treatment according to claim 1, wherein the method is performed by using a device for preparing degradable microspheres for embolism treatment; the device comprises a stationary phase storage tank (1), a microsphere forming device (2) and a microsphere collecting device (3); a stationary phase outlet (1-1) is arranged on the stationary phase storage tank (1); the microsphere forming device (2) comprises an inner tube (2-1) and an outer tube (2-2), the inner tube (2-1) is sleeved in the outer tube (2-2), an annular cavity (2-3) is formed between the inner tube (2-1) and the outer tube (2-2), micropores (2-4) are formed in the side wall of the inner tube (2-1), one end of the inner tube (2-1) is provided with a stationary phase inlet (2-5) communicated with the inner tube, and the outer tube (2-2) is provided with a microsphere outlet (2-6) and a mobile phase inlet (2-7) communicated with the annular cavity (2-3); the microsphere collecting device (3) is provided with a microsphere inlet (3-1) and a mobile phase outlet (3-2); the stationary phase outlet (1-1) is communicated with the stationary phase inlet (2-5) through a pipeline I (4), the microsphere outlet (2-6) is communicated with the microsphere inlet (3-1) through a pipeline III (6), and the mobile phase outlet (3-2) is communicated with the mobile phase inlet (2-7) through a pipeline II (5).

7. The method for preparing degradable microspheres for embolism treatment according to claim 6, wherein the microsphere collecting device (3) is provided with a screen (3-3), the size of the screen (3-3) is smaller than the diameter of the micropores (2-4); the diameter of the micropores (2-4) is 50-100 μm.

8. The method for preparing degradable microspheres for embolism treatment according to claim 6, wherein a valve (7) and a pressure gauge (8) are arranged on the pipeline I (4), a valve (7) is arranged on the pipeline II (5), and a pump (9), a valve (7) and a pressure gauge (8) are arranged on the pipeline III (6).