JP2001095825A - Powder medicine spray for animal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably give the powder medicine to the lung of a small animal by diffusing the powder medicine in granule. SOLUTION: A spray nozzle 10 is long and small in diameter, and the spray nozzle 10 can be inserted in the trachea, the lung, etc., of a small animal. In addition, the powder medicine in a powder medicine storage chamber 4 can be diffused in granule by the turbulence or the swirl formed by the air from a pump 5. The powder medicine can be distributed even in the spray nozzle long and small in diameter. The powder medicine becomes the air flow with the powder medicine mixed therein, and the powder medicine can be stably given in the lung even when the air flow to be fed from the pump 5 is weakened. In addition, a powder medicine spray substantially comprises a spray body 1, the pump 5 and the spray nozzle 10, the number of part items is reduced, the manufacturing cost is reduced, and the powder medicine spray can be used in a disposable manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medicine powder sprayer suitable for use in administering medicine powder to the lungs of small animals, for example.

[0002]

2. Description of the Related Art Generally, when a new drug is produced, various tests are performed. One of the tests is a test using small animals.

[0003] Here, for example, when a medicinal powder is administered to the lungs or the like, if the animal has a certain size such as a dog, the medicinal powder can be administered to the lungs. However, it is difficult to administer drug powder to the lungs of small animals such as rats and hamsters.

Therefore, when administering powder to the lungs of these small animals, since the target lung is very small, a special syringe having a cock at the tip is used, and the powder is applied to this syringe. After filling, the air in the syringe is compressed by the piston. Then, the needle tip of the syringe is inserted into the lungs via the trachea, etc., and by opening the cock in this state, the medicinal powder is ejected from the needle tips using the force of the compressed air to be administered into the lungs. ing.

[0005]

However, in the above-mentioned prior art, the medicine powder is administered to the lungs using the air compressed by the piston, so that the medicine powders flow into the lungs of small animals at once. There is a problem that the lungs may be damaged.

Further, when air is compressed by the piston, the filled powder is also compressed, so that some powder remains in the syringe without being diffused, and a prescribed amount of powder is administered. There is a problem that you can not.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to stably administer a drug powder to the lungs of an animal by diffusing and atomizing the drug powder. An object of the present invention is to provide a veterinary medicine powder sprayer which can be used.

[0008]

According to a first aspect of the present invention, there is provided a medicine sprayer for an animal, which is provided with a medicine storage chamber therein, and a sprayer body. A pump that is provided on the base end side and supplies air toward the medicine powder storage chamber, and a spray nozzle that is provided on the distal end side of the sprayer main body and sprays medicine powder in the medicine powder storage chamber, The spray nozzle is configured to be elongated in the axial direction and formed to have a small diameter in order to administer the medicinal powder to the lungs of the animal.

With this configuration, when the medicament powder is to be administered to the trachea, lungs, etc. of an animal, the tip of the spray nozzle is inserted into the lungs of the animal, and the pump is pressed in this state. The air supplied from the pump to the powder storage chamber is
The medicine powder accommodated in the medicine accommodation chamber is diffused and atomized. With this, even if the spray nozzle is long and small,
The atomized medicine powder can be distributed in the spray nozzle, and the medicine powder can be administered to the lung. In addition, since the atomized powder is mixed with air, the powder can be stably sprayed from the spray nozzle even when the force of the air supplied from the pump is weakened.

According to the invention of claim 2, the spray nozzle is
The inner tube is provided on the outer peripheral side of the inner tube, the inner tube being a medicine powder passage through which the medicinal powder from the medicinal powder accommodating chamber flows, and the tip side protruding from the inner tube, being provided between the inner tube. It is constituted by an outer tube having an annular passage, and an air communication hole that opens the annular passage to the atmosphere in order to reduce the flow rate of the air when air is supplied by a pump.

With this configuration, when the distal end of the outer tube is inserted into the trachea, lungs, etc. of the animal and the pump is pressed, the powder from the powder container in the inner tube is discharged by the air from the pump. It flows into the outer tube through the passage and is administered to the lungs from the outer tube.
At this time, the atmosphere is sucked from the atmosphere communication hole through the annular passage, so that the atmosphere reduces the flow velocity of the medicine powder air flow containing the medicine powder, and suppresses the force of the sprayed medicine powder.

According to the third aspect of the present invention, the spray nozzle comprises:
An inner tube whose inner peripheral side is a medicine powder passage through which the medicinal powder from the medicament powder accommodating chamber flows, and a distal end side which is shorter than the inner tube and is provided on the outer peripheral side of the inner tube,
An outer tube having an annular passage between the inner tube and the inner tube, and an atmosphere communication hole for opening the annular passage to the atmosphere in order to release breath from the lungs to the atmosphere.

With this configuration, when the tips of the inner tube and the outer tube are inserted into the trachea, lungs, and the like of the animal and the pump is pressed, the powder from the powder container in the powder container is released by the air from the pump. Is administered to the lungs through the powder passage. Also, when the medicinal powder is administered, the lungs are breathing, but the exhaled air from the lungs flows into the annular passage and is discharged from the atmosphere communication hole to the atmosphere. Therefore, the medicine powder can be stably administered to the lungs even when the timing between the respiratory action and the medication is shifted.

According to the fourth aspect of the present invention, the sprayer main body is provided with an air inflow passage through which air flows from the pump toward the medicine powder accommodating chamber, and the air inflow passage is formed by bending a middle portion of the passage. There is provided a powder backflow prevention passage for preventing the powder in the powder chamber from flowing back to the pump side.

[0015] With this configuration, even if the expiration of the animal flows in from the spray nozzle, the medicine powder backflow prevention means prevents the medicine powder in the medicine powder storage chamber from flowing back to the pump side through the air inflow passage. Can be prevented.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a medicine powder sprayer for animals according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example the case where a medicine powder is administered to small animals such as rats.

First, FIGS. 1 and 2 show a first embodiment of the present invention. Reference numeral 1 denotes a sprayer main body which constitutes a main part of an animal powder sprayer. It is composed of a powder container 2 and a lid 3.

Reference numeral 2 denotes a medicine powder accommodating cylinder which forms the lower half of the sprayer main body 1. The medicine powder accommodating cylinder 2 comprises a cylinder 2A and a cylinder 2A.
A is formed in a bottomed cylindrical shape with a bottom 2B that closes the lower side of A. Also, the upper part of the cylindrical portion 2A has a small diameter,
A male screw 2C is engraved on the outer peripheral side. A valve housing 2D for accommodating a discharge valve 7 described below is formed below the bottom 2B, and an air supply for communicating the valve housing 2D with a pump 5 described below is formed below the valve housing 2D. A passage 2E is formed.

Reference numeral 3 denotes a lid for closing the upper side of the powder storage cylinder 2. The lid 3 is composed of a cylinder 3A and a lid 3B, and a nozzle holder extending upward on the upper surface of the lid 3B. A cylinder 3C is provided, and the inside is a discharge passage 3D. In addition, cylindrical part 3
On the inner peripheral side of A, a female screw 3E screwed to the male screw 2C of the chemical powder storage cylinder 2 is engraved.

Reference numeral 4 denotes a medicine powder storage chamber provided extending in the axial direction between the medicine powder storage cylinder 2 and the lid 3, and the medicine powder storage chamber 4 contains, for example, a powdery medicine (hereinafter referred to as a medicine). Powder).

Reference numeral 5 denotes a pump having a cylindrical shape with a bottom made of a rubber material. The opening side of the pump 5 is air-tightly fitted to the outer peripheral side of the chemical powder container 2. A suction valve 6 is provided on the bottom side of the pump 5 when the outside air is sucked into the pump 5, and a discharge valve 7 is provided on a valve body housing portion 2 </ b> D of the chemical powder housing cylinder 2. ing.

Numerals 8 and 8 designate two chemical powder backflow prevention passages provided in the chemical powder storage cylinder 2. Each of the chemical powder backflow prevention passages 8 is provided with the chemical powder in the chemical powder storage chamber 4 on the pump 5 side. To prevent backflow to Each of the powder backflow prevention passages 8 has an axial passage 8A extending upward from the valve body housing portion 2D, and a lower side gradually inclined downward and outward from the tip of the axial passage 8A toward the outside in the radial direction. The inclined passage 8B and the lower inclined passage 8
An intermediate passage 8C extending upward from the front end of B, and an upper inclined passage 8D gradually inclined downward toward the inside in the radial direction from the front end of the intermediate passage 8C, and is formed to be bent substantially in a crank shape; The distal end of the upper inclined passage 8D communicates with the lower part of the chemical powder storage chamber 4 from the radial direction.

Here, the upper inclined passages 8D, 8D of the powder backflow prevention passages 8, 8 are opened toward the center of the axis, for example, on the inner surface of the powder storage chamber 4. As a result, the air flowing into the powder storage chamber 4 from the powder backflow prevention passage 8 collides with each other or collides with the inner surface of the powder storage chamber 4 to generate a turbulent flow. The chemical powder in the chamber 4 is dispersed and atomized. When the upper inclined passages 8D, 8D of the powder backflow preventing passages 8, 8 are opened in the inner surface of the powder storage chamber 4, for example, at positions eccentric from the axis center, the respective powder backflow preventing passages 8 Since the air flowing into the chemical powder storage chamber 4 generates a swirl flow in the chemical powder storage chamber 4, the chemical powder in the chemical powder storage chamber 4 can be diffused and atomized by the swirl flow.

The valve housing 2 of the chemical powder housing cylinder 2
D, an air supply passage 2E and a chemical powder backflow prevention passage 8 constitute an air inflow passage 9. This air inflow passage 9
Is for flowing air supplied from the pump 5 toward the chemical powder storage chamber 4.

On the other hand, reference numeral 10 denotes a spray nozzle attached to the tip of the nozzle holding cylinder 3C of the lid 3, and the spray nozzle 10
As shown in FIG. 2, it is long in the axial direction, for example, has a length L of 70 so that it can be inserted into the trachea, lungs, etc. of a small animal.
mm and a small diameter, for example, the diameter D1 is 1 m
m. The inner peripheral side of the spray nozzle 10 communicates with the discharge passage 3D, and the medicine powder passage 11 (passage inner diameter D) through which the medicine powder airflow containing the medicine powder from the medicine powder storage chamber 4 flows.
2 is about 0.7 mm).

The animal medicine sprayer according to the present embodiment is
It is configured as described above. Next, its use operation will be described.

First, the medication preparation operation will be described. In this medication preparation operation, the lid 3 is detached from the powder storage cylinder 2, the powder is filled in the drug powder storage chamber 4, and then the lid 3 is attached to the powder storage cylinder 2 again.

Next, a description will be given of a dosing operation for administering a medicinal powder. In this dispensing operation, the tip of the spray nozzle 10 is inserted into the trachea, lungs, etc. of the small animal, and the pump 5 is pressed in this state. As a result, the air supplied from the pump 5 opens the discharge valve 7 to open the air supply passage 2E,
The fluid flows through the valve body housing portion 2D and each of the medicine powder backflow prevention passages 8 and flows into the medicine powder housing chamber 4. The air that has flowed into the chemical powder storage chamber 4 generates a turbulent flow or a swirling flow in the chemical powder storage chamber 4, and diffuses and atomizes the chemical powder. The atomized medicine powder is mixed into the air to form a medicine powder air flow, and is administered into the lung from the discharge passage 3D of the lid 3 and the medicine powder passage 11 of the spray nozzle 10.

Thus, according to the present embodiment, since the spray nozzle 10 is formed to be long and small in the axial direction, the spray nozzle 10 can be inserted into the lungs of a small animal.
Moreover, the chemical powder filled in the chemical powder storage chamber 4 can be dispersed and atomized by a turbulent flow and a swirling flow formed by the air supplied from the pump 5, so that a long, small-diameter spray nozzle is used. Even with 10, the medicine powder can be distributed.
Further, since the medicine powder is administered as a medicine powder air stream mixed into the air, it is possible to stably administer the medicine powder into the lungs even in a state where the force of the air supplied from the pump 5 is weakened. it can.

As a result, when the medicinal powder is administered to the lungs of a small animal, the medicinal powder can be prevented from flowing at once and can be administered gently to the lungs. Further, a prescribed amount of the medicinal powder can be administered without leaving the medicinal powder in the medicinal powder accommodating chamber 4, and the efficacy of the medicinal powder can be enhanced.

Further, since the chemical powder backflow prevention passage 8 for supplying air to the chemical powder storage chamber 4 is provided so as to be bent in a crank shape, the chemical powder flows backward from the chemical powder storage chamber 4 to the pump 5 side. Can be prevented and most medicine powder can be administered.

Further, the chemical powder sprayer can be substantially constituted by the sprayer body 1, the pump 5, and the spray nozzle 10, and the number of parts can be reduced. As a result, the manufacturing cost can be reduced, so that the chemical sprayer according to the present embodiment can be used as a disposable type.

Next, FIG. 3 shows a second embodiment of the present invention. The feature of this embodiment is that the spray nozzle has an inner peripheral side on which the powder from the powder storage chamber flows. An inner tube serving as a passage, an outer tube having a leading end protruding beyond the inner tube and provided on an outer peripheral side of the inner tube, and having an annular passage between the inner tube and the inner tube; In order to reduce the flow velocity of the air, the annular passage is constituted by an air communication hole that opens to the atmosphere. In the present embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

A spray nozzle 21 according to the present embodiment is used in place of the spray nozzle 10 according to the first embodiment.
2, the outer tube 24 and the atmosphere communication hole 26.

Reference numeral 22 denotes an inner tube. The inner tube 22 has its proximal end fitted to the nozzle holding cylinder 3C.
The distal end side is opened at an intermediate position in the length direction of the outer tube 24. The inner tube 22 has a discharge passage 3D.
Is formed as a chemical powder passage 23 communicating with.

Numeral 24 denotes an outer tube provided on the outer peripheral side of the inner tube 22. The outer tube 24 has a base end fitted to the nozzle holding tube 3C and a distal end protruding from the inner tube 22. . An annular passage 25 is formed in the outer tube 24 between the outer tube 24 and the inner tube 22.

Numerals 26, 26 are provided in the nozzle holding cylinder 3C and are air communication holes communicating with the annular passage 25. The air communication holes 26 are used to supply air when a pump (not shown) supplies air. The air is introduced into the annular passage 25 to reduce the flow velocity.

The spray nozzle 21 configured as described above is
When the distal end of the outer tube 24 is inserted into the lungs of a small animal or the like to administer the drug powder, a drug powder air flow containing the drug powder flows out into the outer tube 24 through the drug powder passage 23 in the inner tube 22. Is administered to the lung from the outer tube 24.

At this time, when the chemical powder air flow flows out to the outer tube 24, the air flows into the outer tube 24 through the air communication hole 26 and the annular passage 25 as shown by an arrow A in FIG. Therefore, the flow rate of the chemical powder air flow can be reduced by this atmosphere, and the force of the sprayed chemical powder can be suppressed.

Thus, according to the present embodiment configured as described above, the force of the air flow of the medicinal powder can be further reduced, so that the medicinal powder can be more gently administered to the lungs of the small animal.

Next, FIG. 4 shows a third embodiment of the present invention. The feature of this embodiment is that the spray nozzle has an inner peripheral side in which the powder from the powder storage chamber flows. An inner tube serving as a passage; an outer tube having a distal end side shorter than the inner tube and provided on an outer peripheral side of the inner tube, having an annular passage between the inner tube and the inner tube; And an atmosphere communication hole that opens the annular passage to the atmosphere for escape to the atmosphere. In the present embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 31 denotes a spray nozzle according to this embodiment which is used in place of the spray nozzle 10 according to the first embodiment.
2. It is composed of an outer tube 34 and an atmosphere communication hole 36.

Reference numeral 32 denotes an inner tube. The inner tube 32 has a proximal end fitted to the nozzle holding cylinder 3C and a distal end extending longer than the outer tube. The inside of the inner tube 32 is a chemical powder passage 33 communicating with the discharge passage 3D.

Reference numeral 34 denotes an outer tube provided on the outer peripheral side of the inner tube 32. The outer tube 34 has a proximal end fitted to the nozzle holding tube 3C and a distal end shorter than the inner tube 32. An annular passage 35 is formed in the outer tube 34 between the outer tube 34 and the inner tube 32.

Numerals 36, 36 are provided in the nozzle holding cylinder 3C and are air communication holes which communicate with the annular passage 35. The air communication holes 36 indicate the expiration from the lung supplied through the annular passage 35 from the lungs B. The air is released to the atmosphere as shown by.

The spray nozzle 31 configured as above is
When the tips of the inner tube 32 and the outer tube 34 are inserted into the lungs or the like of a small animal to administer the medicine powder, the medicine powder is administered to the lung through the medicine powder passage 33 in the inner tube 32. At the time of this medication, the lungs are breathing, but the expiration from the lungs is as shown by arrow B.
5 and can be discharged from the atmosphere communication hole 36 to the atmosphere.

Thus, according to the present embodiment configured as described above, the medicine powder can be stably administered irrespective of the respiratory movement of the lungs, so that the administration operation can be easily performed. In addition, it is possible to prevent the medicine powder from flowing backward due to exhalation.

[0048]

As described in detail above, according to the first aspect of the present invention, the sprayer main body provided with the chemical powder storage chamber therein, and the chemical powder storage chamber provided at the base end side of the sprayer main body. And a spray nozzle provided on the tip side of the sprayer body and spraying the powder in the powder storage chamber, wherein the spray nozzle administers the powder to the animal's lungs. Therefore, it is configured to be long and small in the axial direction. Therefore, when administering a powder to the lungs of a small animal, the tip of the spray nozzle is inserted into the trachea, lungs, etc. of the small animal, and by pressing the pump in this state, the powder supplied from the pump is stored by the air supplied from the pump. The medicine powder stored in the room can be diffused and atomized. Thus, even if the spray nozzle is long and small in diameter, the atomized medicine powder can be circulated in the spray nozzle, and the medicine powder can be administered to the lung. Further, since the chemical powder can be atomized and mixed into the air, the chemical powder can be stably sprayed from the spray nozzle even in a state where the force of the air supplied from the pump is weakened.

As a result, when the medicinal powder is administered to the lungs of a small animal or the like, the force of the air can be reduced to gently administer the medicinal powder, and the lung damage can be reduced. In addition, a prescribed amount of the medicinal powder can be administered without leaving the medicinal powder in the medicinal powder accommodating chamber, and the efficacy of the medicinal powder can be enhanced. Further, the chemical powder sprayer is constituted by the sprayer body, the pump, and the spray nozzle, so that the number of parts can be reduced, the manufacturing cost can be reduced, and the chemical powder sprayer can be used as a disposable type.

According to the second aspect of the present invention, the spray nozzle is
The inner tube has an inner tube that is a medicine powder passage through which the medicine powder from the medicine-powder accommodating chamber flows, and the tip side is provided on the outer periphery of the inner tube so as to protrude beyond the inner tube, and between the inner tube and the inner tube. Since the outer tube has an annular passage and an air communication hole that opens the annular passage to the atmosphere to reduce the flow velocity of the air when air is supplied by the pump, the distal end of the outer tube is used for a small animal. By inserting it into the lungs and pressing the pump,
By the air from the pump, the medicinal powder in the medicament powder accommodating chamber flows out into the outer tube through the medicament powder passage in the inner tube, and can be administered to the lungs from the outer tube.
At the time of this medication, the atmosphere is sucked from the atmosphere communication hole through the annular passage, so that the flow rate of the medicine powder air flow containing the medicine powder can be reduced by this atmosphere, and the force of the sprayed medicine powder can be suppressed. As a result, the air can reduce the flow of the powder air, and the powder can be gently administered to the lungs of the animal.

According to the third aspect of the present invention, the spray nozzle
An inner tube whose inner peripheral side is a medicine powder passage through which the medicinal powder from the medicament powder accommodating chamber flows, and a distal end side which is shorter than the inner tube and is provided on the outer peripheral side of the inner tube,
An outer tube having an annular passage between the inner tube and the inner tube, and an atmosphere communication hole that opens the annular passage to the atmosphere to release the breath from the lungs to the atmosphere. By inserting the tip into the lungs of a small animal or the like and pressing the pump, it is possible to administer the medicinal powder in the medicinal powder storage chamber to the lungs from the medicinal powder passage in the inner tube by the air from the pump. Also,
When the medicament powder is administered, the lungs are performing respiratory action, but exhalation from the lungs can flow into the annular passage and be discharged from the atmosphere communication hole to the atmosphere. Therefore, even when the timing between the respiratory operation and the medication is shifted, the medicine powder can be stably administered to the lung, and the medication operation can be easily performed. In addition, it is possible to prevent the medicine powder from flowing backward due to exhalation.

According to the fourth aspect of the present invention, the sprayer main body is provided with an air inflow passage through which air flows from the pump toward the chemical powder storage chamber, and the air inflow passage is formed by bending a part of the passage. The medicine powder backflow prevention passage is provided to prevent the medicine powder in the medicine powder accommodating chamber from flowing back to the pump side. It is possible to prevent the medicine powder in the room from flowing back to the pump side through the air inflow passage, and to administer most of the medicine powder filled in the medicine powder storage chamber.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an animal medicine sprayer according to a first embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of a main part showing a spray nozzle and the like in FIG. 1 in an enlarged manner.

FIG. 3 is an enlarged vertical sectional view of a main part at a position similar to FIG. 2 showing a spray nozzle according to a second embodiment of the present invention.

FIG. 4 is an enlarged vertical sectional view of a main part at a position similar to FIG. 2 showing a spray nozzle according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sprayer main body 2 Chemical powder accommodating cylinder 4 Chemical powder accommodating chamber 5 Pump 8 Chemical powder backflow prevention passage 9 Air inflow passage 10, 21, 31 Spray nozzle 11, 23, 33 Chemical powder passage 22, 32 Inner tube 24, 34 Outer Tube 25, 35 Annular passage 26, 36 Atmospheric communication hole

Continuing from the front page (72) Inventor Yoshiyuki Tanizawa 1370 Onna, Atsugi-shi, Kanagawa Prefecture Inside Unisia Gex Co., Ltd. Inventor Shigemi Nakamura 1370 Onna, Atsugi-shi, Kanagawa Prefecture Inside Unisia Gex Co., Ltd. (72) Inventor Akira Yanagawa 5-3 Fujimigaoka, Tsuzuki-ku, Yokohama-shi, Kanagawa Prefecture

Claims (4)

[Claims] 1. A sprayer main body having a medicine powder storage chamber provided therein, a pump provided at a base end side of the sprayer main body and supplying air to the medicine powder storage chamber, and a distal end side of the sprayer main body. And a spray nozzle for spraying the medicinal powder in the medicament powder accommodating chamber, wherein the spray nozzle is long in the axial direction to administer the medicinal powder to the lungs of an animal, and has a small diameter. Animal powder sprayer. 2. The spray nozzle has an inner tube on the inner peripheral side serving as a medicine powder passage through which the medicinal powder from the medicinal powder storage chamber flows, and an outer peripheral side of the inner tube protruding from a tip end side of the inner tube. And an outer tube having an annular passage between the inner tube and the inner tube, and an atmosphere communication hole that opens the annular passage to the atmosphere in order to reduce the flow rate of the air when air is supplied by the pump. The animal medicine powder sprayer according to claim 1, wherein the sprayer comprises: 3. The spray nozzle has an inner tube having an inner peripheral side serving as a medicine powder passage through which the medicinal powder from the medicinal powder storage chamber flows, and a distal end having a shorter length than the inner tube. An outer tube provided on an outer peripheral side and having an annular passage between the inner tube and the inner tube, and an atmosphere communication hole which opens the annular passage to the atmosphere to release breath from the lungs to the atmosphere. 2. The animal medicine sprayer according to item 1. 4. An air inflow passage through which air flows from the pump to the powder storage chamber in the sprayer main body, and the air inflow passage is bent at an intermediate portion of the passage so that the inside of the powder storage chamber is bent. The animal medicine sprayer according to claim 1, 2, or 3, further comprising a medicine powder backflow prevention passage for preventing the medicine powder from flowing back to the pump side.