JPH1057483A - Syringe and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a syringe and a manufacturing method capable of fluid-tightly filling a sterilized injection agent inside an outer jacket even without performing a sterilization processing by autoclave sterilization by closing a passage by thermal melt-sticking after filling the injection agent for the filling passage of the injection agent. SOLUTION: After the outer jacket 2 of this syringe 1 is assembled and a gasket 4A and a plug body 5 are completely combined, the inside of the outer jacket 2 is sterilized and also, the injection agent 3 is sterilely filled inside the outer jacket 2 after the processing through the filling passage 14. At the time of the filling, since the injection agent 3 is sterilely filled inside the outer jacket 2 without being in contact with an external environment at all, the sterilization guarantee is improved. For the filling passage, since the passage is closed by the thermal melt-sticking after filling the injection agent, even without performing the sterilization processing completely by the autoclave sterilization, the sterilized injection agent is fluid-tightly filled inside the outer jacket. In this manufacturing method of the syringe 1, though there is the possibility of being in contact with the external environment only at the moment of connecting a supply nozzle to the filling passage 14, the tip part of the supply nozzle is chemically processed or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a syringe (pre-field syringe) or the like pre-filled with an injection (medical solution), and more particularly, to a syringe filled with an injection in a state of assurance of high sterility. And a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, there has been provided a syringe in which a drug solution to be administered is previously aseptically filled in a syringe (pre-field syringe). Such syringes are expected to prevent hospital-acquired infections at medical sites and eliminate administration errors. The syringe generally comprises an outer cylinder and a plunger, and the injection solution is one that is aseptically filled between a gasket and a stopper, or one that is autoclaved together with the outer cylinder after filling. Also, the plug is of a structure attached to the injection port of the outer cylinder, or a slidable inner plug is provided in the outer cylinder, and between the inner wall surface of the outer cylinder and the outer wall surface of the inner plug. A device having a structure provided with bypass means has been proposed. As for a syringe having a structure provided with an inner plug, a two-component or more multi-component syringe filled with a drug solution and a mixed drug (solid or liquid) has been proposed.

[0003]

However, the conventional syringe has the following problems. First, it is difficult to guarantee sterility of the injection. When aseptically filling a syringe, at least one of a stopper and a gasket is attached to the outer cylinder, and the injection is filled into the outer cylinder through a sterilization filter from the other outer cylinder filling port. And closed liquid-tight. Such an operation is always performed in a sterile room, particularly in a clean room with high cleanliness. But,
Even with such aseptic filling, the injection has a long contact period with the outside world during the operation, so that sterility cannot be assured. In particular, in the case of a two-component syringe, aseptic filling is indispensable when one drug is filled with a lyophilized product, but further aseptic filling of an injection after filling the lyophilized product is difficult. Accompany. Second, in the case where an injection is liquid-tightly filled in an outer cylinder and then subjected to autoclave sterilization, sterilization is sufficiently guaranteed, but the amount of filler is limited. In particular, it is difficult to fill a drug that is weak to heat treatment. In recent years, the outer cylinder has been changed from glass to resin. This is because the resin outer cylinder is lightweight, has less damage, and is easy to dispose and incinerate. However, some resin outer tubes are deformed by heating during autoclave sterilization, and may not be used. Accordingly, an object of the present invention is to provide a syringe capable of reliably filling an outer cylinder with a sterile-treated injection liquid-tight without performing a complete sterilization treatment by autoclave sterilization and a method of manufacturing the same. .

[0004]

According to the present invention, there is provided a syringe in which an injection is previously aseptically filled in an outer cylinder, wherein at least a part of the outer cylinder is made of resin, and The above-mentioned object has been achieved by providing a syringe characterized by forming a filling passage for the injection, wherein the filling passage is closed by heat welding after filling the injection. is there. Further, the present invention provides the method for manufacturing a syringe, wherein a gasket and a plug for liquid-tightly filling the injection are attached to the outer cylinder, assembled, and then the inside of the outer cylinder is sterilized. A method of manufacturing a syringe, wherein the injection nozzle is aseptically filled into the outer cylinder from the supply nozzle, and the filling passage is closed by heat welding after the filling. Thereby, the above object has been achieved.

[0005] The outer cylinder is entirely or at least partially made of a resin member. For example, the entire outer cylinder may be formed by injection molding of resin, or the cylinder may be made of glass and the injection port may be made of resin. However, in the present invention, a passage for filling the injection is formed in the resin part. The resin member is made of a transparent resin molding, and the resin molding is a thermoplastic resin. The resin molded article may have a single structure or a laminated structure of a plurality of materials. As the thermoplastic resin, polyethylene, polypropylene, 4-methylpentene-1, styrene-based resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyacrylonitrile , A cyclic gen-based polymer, an acrylic resin, a polyamide, a polyester, a polycarbonate, a polyacetal, a fluorine-based resin and the like. Especially,
For accommodating the drug, an olefin-based resin free of eluted substances such as chlorine and metal is desirable. Among them, polyethylene, polypropylene, 4-methylpentene-1, and a cyclic gen-based polymer having safety and transparency are the innermost layers. Is desirable.

There is no limitation on the size or shape of the filling passage formed in the resin member as long as the inside and outside of the outer tube communicate with each other. The passage is closed in a liquid-tight manner without contacting air or a jig. Further, even when a plunger or the like is pushed into the outer cylinder, the melted closing portion is not broken. Therefore, the filling passage must have a certain length as long as it can be blown out of the resin member. The length of the filling passage depends on the diameter and shape of the passage, but considering contact of the jig, at least 2.0 mm
The above length is required. The injection solution to be administered is aseptically filled into the outer cylinder through a sterilizing filter or the like. good. When the injection is classified, it may be a liquid-liquid or liquid-solid filled drug solution.
The plunger is composed of a rod and a gasket, and the gasket and the plug are composed of an elastic material such as rubber, elastomer or the like in order to accommodate the injection liquid-tightly.

In the method for manufacturing a syringe according to the present invention,
First, after molding the outer cylinder, plunger and stopper, etc.
dry. Then, a gasket and a plug of the plunger are inserted or attached to a predetermined position of the outer cylinder. The assembled syringe is sterilized and supplied to a sterile filling chamber. Examples of the sterilization process of the assembled syringe include a heat sterilization process such as auto-cooling sterilization, a chemical sterilization process of exposing to a sterilizing gas and a sterilizing liquid, and an irradiation sterilization process. Examples of the sterilizing gas include ethylene oxide and hydrogen peroxide, and examples of the liquid include alcohol and formalin. Further, examples of the irradiation sterilization treatment include γ-rays, electron beams, and ultraviolet rays. In such a case, it is preferable that a sterilization filter or the like is provided in the filling passage in advance to perform sterilization processing, and the inside of the outer cylinder for filling is maintained aseptically. According to such a configuration, there is no possibility that the inside of the outer cylinder is contaminated with the outside air during the transfer to the aseptic filling chamber.

After sterilization, the assembled syringe is transported to a sterile filling chamber, and a supply nozzle of the filling chamber is aseptically connected to the filling passage. Then, the injection is filled from the supply nozzle into the inside of the outer cylinder between the gasket and the plug via the filling passage. When there is a sterilization filter in the filling passage, the sterilization filter can be broken and connected by the supply nozzle, and the supply nozzle is connected between the sterilization filters to fill the solution. Next, although the supply nozzle may be left attached, the intermediate portion of the filling passage is thermally melted by a heating cutting jig or the like, and the filling passage is closed. At the time of thermal fusing, it is performed so that the outside air does not touch the filling passage and the jig and the like do not touch. Thereby, the syringe according to the present invention can be manufactured. In the syringe configured as described above, after the inside of the outer cylinder is completely sterilized, the injection is filled as aseptically as possible, and since the injection does not come into contact with the outside world, the aseptic assurance is guaranteed. It will be more reliable. Also, when the syringe is used, even if the gasket is pressed, the filling passage is securely closed by heat welding, so that no liquid leakage or the like occurs at the time of sliding.

A third aspect of the present invention is directed to a method of manufacturing a syringe, which aims to further enhance sterilization assurance when filling an injection. That is, a method of manufacturing a syringe according to claim 3 is characterized in that a sterilization filter is provided at the opening of the filling passage, and the supply nozzle is connected via the sterilization filter. By providing such a filter, the inside of the outer cylinder for filling the injection is reliably kept aseptic until it enters the aseptic filling chamber. A fourth aspect of the present invention is directed to a method for manufacturing a syringe, which improves air bleeding in an outer cylinder when an injection is filled. That is, in the manufacturing method according to claim 4, in addition to the filling passage, a discharge passage for discharging gas in the outer cylinder at the time of filling is further provided in the outer cylinder, and the discharge passage is the same as the filling passage. After the agent is filled, the discharge passage is closed by a heat welding means. The method for producing a syringe according to claim 5 of the present invention aims at performing a specific sterilization treatment in an assembled outer cylinder,
In the method of manufacturing a syringe according to the fifth aspect, the sterilization in the outer cylinder is irradiation sterilization, heat sterilization, or chemical sterilization.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a syringe according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a side sectional view of a first embodiment of a syringe according to the present invention. FIG.
(A) thru | or (C) are sectional drawings of each member in the syringe of 1st Example. 3 to 6 are cross-sectional views showing the steps of manufacturing the syringe of the first embodiment. The syringe 1 of the first embodiment shown in FIGS. 1 to 6 is a syringe in which an injection 3 is previously aseptically filled in an outer cylinder 2. In the syringe 1, the outer cylinder 2
Is formed of a resin, and a filling passage 14 for the injection agent 3 is formed in the outer cylinder 2 of the resin portion 2B.
In 4, the passage 14 is closed by heat welding after the injection 3 is filled.

The syringe 1 of the first embodiment will be described in more detail. The syringe 1 comprises an outer cylinder 2, a filling injection 3, a plunger 4, and a stopper 5. The outer cylinder 2 includes a distal cylinder member 2A and a proximal cylinder member 2B, and both members 2A and 2B are injection-molded products made of polypropylene. Tip tube member 2
An injection port 11 is formed in A, and a plug 5 made of an elastic material is detachably attached to the injection port 11, and the plug 5 closes the injection port 11 in a liquid-tight manner. A joining port 12 is formed in the distal end cylindrical member 2A, and the joining port 12 has an inner wall surface whose diameter is enlarged. A finger hook 13 is formed on the base tube member 2 </ b> B, and the finger hook 13 is disposed at a base end opening of the outer cylinder 2.
A filling passage 14 and a gas discharge passage 15 are provided in the proximal end cylindrical member 2B.
Are formed, and the two passages 14 and 15 are fused at an intermediate portion thereof to form closed portions 16 and 16. Base tube member 2B
Is formed with a joining port 17, and the joining port 17 is formed with a thin-walled outer wall surface.
The inner wall 2 is heat-sealed in a liquid-tight manner. A plunger 4 is inserted into the outer cylinder 2, and the plunger 4 includes a gasket 4A made of an elastic body and a rod 4B made of a resin molded product. The gasket 4A is made of each member 2A, 2B of the outer cylinder 2.
The base end cylindrical member 2A is slid liquid-tightly on the inner wall surface of the base when not in use.
It is arranged within. The rod 4B has a threaded portion formed at the tip, and is detachably attached to the gasket 4A via the threaded portion. The injection 3 from the filling passage 14 is aseptically filled in the outer cylinder 2 between the gasket 4A and the plug of the injection port 11. The injection 3 contains nutrients such as vitamins and carbohydrates in addition to the therapeutic agent.

Next, a method for manufacturing a syringe according to the present invention will be described with reference to FIGS. As shown in FIGS. 2A to 2C, in the manufacturing method of the syringe 1, the gasket 4A and the plug 5 for liquid-tightly filling the injection agent 3 with the outer cylinder 2 are assembled and assembled. Is sterilized, and then a supply nozzle 19 is connected to the filling passage 14 and the supply nozzle 19
The injection 3 is aseptically filled in the outer cylinder 2 and the filling passage 14 is closed by the heat welding means 20 after filling. More specifically, the distal end tubular member 2A and the proximal end tubular member 2B are manufactured by injection molding of polypropylene. Further, the gasket 4A and the plug 5 are formed from silicon rubber, and the plunger rod 4B is manufactured by injection molding of polypropylene. Each of these members is washed, dried, and the surface is sterilized by gas sterilization. Next, the distal end cylindrical member 2A and the proximal end cylindrical member 2B are joined at the joining ports 12 and 17, and the inner wall surface of the joining port 12 and the outer wall surface of the joining port 17 are liquid-tightly fixed by ultrasonic welding. Cover the injection port 11 with the plug 5 and the base end cylindrical member 2B
Gasket 4A is inserted into the inside. And the filling passage 14
In addition, air filters 18, 18, which are impermeable to bacteria, are attached to the opening at the end of the gas discharge passage 15, and each opening is covered with the air filter 18 so that only air can flow through the outer cylinder 2. As shown in FIG. 3, the assembled outer cylinder 2 is transported to a γ-ray sterilizing chamber, and the outer cylinder 2 is irradiated with γ-ray, and the surface and the inside of the outer cylinder 2 are sterilized. After the sterilization process, the outer cylinder 2 is transferred to the aseptic filling chamber,
A supply nozzle 19 heated while opening the air filter 18 is connected to the filling passage 14 of the outer cylinder 2. Supply nozzle 19
First, the nitrogen gas that has passed through a sterilization filter (not shown) is filled into the outer cylinder 2, and then the injection 3 that has passed through the sterilization filter is filled into the outer cylinder 2 as shown in FIG. 4. in this case,
The nitrogen gas in the outer cylinder 2 is gradually discharged from the discharge passage 16 at the time of filling. As shown in FIG. 5, when the filling of the outer cylinder 2 is completed, the fusing jigs 20 and 20 are respectively approached to the intermediate portions of the filling passage 14 and the discharge passage 15 while the supply nozzle 19 is connected. After the intermediate portion of each of the filling passage 14 and the discharge passage 15 is heated to some extent by the fusing jig 20, the jig 20 is pressed against the intermediate portion to close the fusing closing portions 16, 16.
Is formed, and the passages 14 and 15 are closed in a liquid-tight manner as shown in FIG. After such treatment, the plunger rod 4A is attached, and the entire syringe 1 is packaged in a gas barrier package to obtain a product.

In the syringe 1 thus manufactured, the outer cylinder 2 is assembled, the gasket 4A and the plug 5 are completely assembled, and then the inside of the outer cylinder 2 is sterilized. Can be aseptically filled with the injection agent 3 through the filling passage 14. At the time of such filling, the injection 3 is aseptically filled into the outer cylinder 2 without touching the outside world at all, so that the sterilization assurance is increased. Also, a sterilization filter or an air filter 18 is provided in the filling passage 14 or the like.
Is attached, the inside of the outer cylinder 2 is easily maintained in a sterile state even after the sterilization process, and the sterility is guaranteed until filling. Also,
In the method of manufacturing the syringe 1 of the first embodiment, the supply nozzle 19
There is a possibility that only the moment when is connected to the filling passage 14 is affected by the outside world, but also in this case, if the tip of the supply nozzle 19 is subjected to chemical treatment or heat treatment, no problem occurs. still,
In the above embodiment, the base cylinder member 2A of the outer cylinder 2 is made of resin, but may be made of glass if necessary. The glass is preferable because it does not adversely affect the injection 3 except for the problem of disposal.

Next, a second embodiment of the syringe according to the present invention and a method of manufacturing the same will be described with reference to FIGS. FIG. 7 is a side sectional view of a second embodiment of the syringe according to the present invention. 8 to 10 are sectional views showing the steps of manufacturing the syringe of the second embodiment. The syringe 21 of the second embodiment is a syringe in which an injection 23 is aseptically filled in an outer cylinder 22 in advance. In the syringe 21, at least a part 2 of the outer cylinder 22
2A is made of resin, a filling passage 24 for the injection 23 is formed in the resin portion 22A, and the filling passage 24 is closed by heat welding after the injection 23 is filled.
This is the same as the syringe 1 of the first embodiment in FIG. The differences are found in the following parts.

The tip tube member 22A of the outer tube 22 is formed as a freeze-drying container, and a filling passage 24 and a discharge passage 25 are formed in the tip tube member 22A. FIG. 8 (A)
As shown in (1), the filling passage 24 and the discharge passage 25 are formed to have a length of 10 mm before being blown. Tip tube member 22
An injection port 27 is formed in A, and a liquid-tight plug 28 is detachably attached to the injection port 27. Tip tube member 22A
A groove 29 is formed in the groove, and when a plug described below is located in the groove 29, 29, the liquid flows into the groove 2 outside the plug 41.
9 can be distributed. That is, the groove portion 29
Are formed as bypass means for liquid circulation.
A connection port 30 is formed in the distal end cylindrical member 22A, and the connection port 30 is liquid-tightly fixedly bonded to a connection port of the base member 22B described later. The inner plug 31 described above is provided in the distal end cylindrical member 22A.
Is slidably inserted into the inner wall surface while maintaining the liquid tightness, and a freeze-drying agent 32 is filled in the distal end tubular member 22A.
The freeze-dried agent 32 can be dissolved in the injection 23.
A finger hook 33 is formed at the base end of the base tube member 22B of the outer tube 22, and the joint port 3 of the above-described end tube member 22A is formed at the front end.
A joining port 34 for joining with the “0” is formed. A gasket 35 is slidably disposed in the proximal end tubular member 22B, and the injection 23 is aseptically filled between the gasket 35 and the inner plug 31. A plunger rod 36 is attached to the gasket 35, and the entire syringe 21 is packaged with a packaging material 37 made of a gas barrier film.

Next, a method of manufacturing the syringe 21 according to the second embodiment will be described in detail. First, each member of the outer cylinder 2, each member of the plunger, and the plug are formed of a predetermined resin and an elastic material, and these are washed and dried. After washing and drying, each member is subjected to a gas sterilization process or the like, and is carried into the aseptic filling room. FIG.
As shown in (A), a plug 28 is attached to the injection port 27 of the distal end tubular member 22A, and the distal end tubular member 22A is filled with a chemical solution 32A for freeze-drying. The chemical solution 32A is filled at the previous stage through a sterilization filter (not shown). As shown in FIG. 8B, the inner plug 31 is inserted in a liquid-tight and slidable manner from the joint port 30 of the distal end tubular member 22B, and the filling passage 24 and the discharge passage 2 are inserted.
The inner plug 31 is arranged so as not to block 5. That is, the inner plug 31 is placed in a half-plugged state. Then, in such a state, the medicinal solution 32A is freeze-dried in a freeze dryer. FIG.
As shown in (C), when the freeze-drying of the chemical solution 32A is completed, the inner plug 31 is further pushed into the distal end tubular member 22B,
The inner plug 31 prevents communication between the filling chamber for the lyophilized agent 32 and the filling passage 24 and the discharge passage 25. Also,
In this state, a sterilization filter 38 is connected to the filling passage 24, and a sterilization air filter 39 is attached to the discharge passage 25.

As shown in FIG. 9, the outer cylinder 22 is formed by liquid-tight heat welding of the joint port 30 of the distal cylinder member 22A and the joint port 34 of the proximal cylinder member 22B. Then, the gasket 35 is inserted into a predetermined position of the proximal end tubular member 22B in a liquid-tight and slidable manner. Next, in order to protect the freeze-drying agent 32 of the tip cylinder member 22A, a part of the tip cylinder member 22B is shielded with a shielding material,
The inside of the outer cylinder 22, the inside of the filling passage 24, the inside of the discharge passage 25, and the inside of each of the filters 38 and 39 between the inner plug 31 and the gasket 35 are subjected to γ-ray sterilization. As shown in FIG.
The injection nozzle 23 as a solution is filled into the outer cylinder 22 from the supply nozzle 40 by a predetermined amount. Then, after filling, the respective intermediate portions of the filling passage 24 and the discharge passage 25 are blown off by a fusing jig while the supply nozzle 40 is attached, so that the closing portions 26 of the passages 24 and 25 are formed. Then, the disinfection filter 3
8, and the air filter 39 are separated for reuse.
On the other hand, after the plunger rod 36 is attached to the gasket 35 in the outer cylinder 22 and the syringe 21 is completely assembled,
This is packaged with a gas barrier film 37 to obtain a product.

The thus constructed syringe 21 is provided with the outer cylinder 2.
Since the second end cylindrical member 22A is used as a lyophilization container for the lyophilization agent 32, it is possible to easily achieve economy and labor saving in the manufacturing process. Since the outer cylinder 22 is assembled and sterilized inside the outer cylinder 22 to be filled with the injection 23, no contact is made with the outside world until the final manufacturing process. Is almost completely done. When using the syringe 21, first, the stopper 28 is removed from the injection port 26, and the injection needle is attached to the injection port 26. Hold the syringe 21 with the injection port 26 up, and slowly push the plunger rod 41. Thereby, the gasket 35 slides in the outer cylinder 22 and the inner plug 31 slides. When the inner plug 31 is located in the groove 29 serving as the bypass means, the inner plug 31 stops but the gasket 35 slides as it is. By such sliding, the space between the inner plug 31 and the gasket 35 is contracted, and first, the air accumulated between the inner plug 31 and the gasket 35 flows to the injection port 27 through the groove 29, Then, the injection 23 as a solution flows toward the injection port 27. Thereby, the freeze-dried agent 32 dissolves in the injection 23. After dissolution,
After the air in the syringe 21 is evacuated, it is applied to the patient. Therefore, in the present invention, the bypass means of the distal end tubular member 22B is not limited to the structure of the groove portion 29, and may have an enlarged inner wall surface. It may be. Further, the number of the inner plugs 31 is not limited to one as in the present embodiment, and a plurality of them may be provided to be used as a multi-component syringe, or a liquid-liquid component may be used. Further, in each of the above embodiments, the sterilization in the outer cylinders 2 and 22 is γ-ray sterilization. However, in the present invention, chemical sterilization with ethylene oxide gas, or chemical sterilization with a liquid such as alcohol or formalin may be used. If a member having heat resistance is used, heat drying sterilization or heat steam sterilization may be used. Further, the sterilization may be performed not only by the γ-ray sterilization as described above but also by an electron beam or ultraviolet rays.

[0019]

As described above, in the syringe according to the present invention in which the injection is previously aseptically filled in the outer cylinder, at least a part of the outer cylinder is made of resin, and the outer cylinder of the resin-made portion is made. The filling passage for the injection is formed in the outer tube without filling the passage with autoclave sterilization because the passage is closed by heat welding after filling the injection. Aseptically processed injections can be reliably filled in a liquid-tight manner

[Brief description of the drawings]

FIG. 1 is a side sectional view of a first embodiment of a syringe according to the present invention.

FIGS. 2A to 2C are cross-sectional views of each member in the syringe of the first embodiment.

FIG. 3 is a sectional view showing a manufacturing process of the syringe of the first embodiment.

FIG. 4 is a sectional view showing a manufacturing process of the syringe of the first embodiment.

FIG. 5 is a sectional view showing a manufacturing process of the syringe of the first embodiment.

FIG. 6 is a sectional view showing a manufacturing process of the syringe of the first embodiment.

FIG. 7 is a side sectional view of a second embodiment of the syringe according to the present invention.

FIG. 8 is a sectional view showing a manufacturing process of the syringe of the second embodiment.

FIG. 9 is a sectional view showing a manufacturing process of the syringe of the second embodiment.

FIG. 10 is a sectional view showing a manufacturing process of the syringe of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Syringe 2 Outer cylinder 2A Tip cylinder member 2B Base cylinder member 3 Injection 4 Plunger 4A Gasket 4B Rod 5 Plug 11 Injection port 14 Filling passage 16 Closed part

Claims (5)

[Claims] 1. A syringe in which an injection is previously aseptically filled in an outer cylinder, wherein at least a part of the outer cylinder is made of resin, and a filling passage for the injection is formed in the outer cylinder of the resin part. The filling passage is closed by heat welding after the filling of the injection. 2. The method for manufacturing a syringe according to claim 1, wherein a gasket and a plug for liquid-tightly filling the injection are attached to the outer cylinder and assembled, and then the inside of the outer cylinder is sterilized. Connect the supply nozzle to the filling passage opening,
A method for manufacturing a syringe, wherein the injection is aseptically filled into an outer cylinder from a supply nozzle, and the filling passage is closed by a heat welding means after the filling. 3. The method for manufacturing a syringe according to claim 2, wherein a sterilization filter is provided at an opening of the filling passage, and the supply nozzle is connected through the sterilization filter. 4. In addition to the filling passage, a discharging passage for discharging gas in the outer cylinder at the time of filling is further provided in the outer cylinder, and the discharging passage is, like the filling passage, discharged after filling the injection. 4. The method for manufacturing a syringe according to claim 2, wherein the passage is closed by a heat welding means. 5. The method for manufacturing a syringe according to claim 2, wherein the sterilization in the outer cylinder is irradiation sterilization, heat sterilization, or chemical sterilization.