Patent Publication Number: US-2018043099-A1

Title: Barrel with needle and syringe including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No, 2015-044877, filed on Mar. 6, 2015, the disclosure of which is incorporated herein by reference in its entirety. 
     FIELD 
     The present invention relates to a barrel with needle including an injection needle, and a syringe including the barrel with needle. 
     BACKGROUND 
     Conventionally a syringe including a barrel with needle including an injection needle (hereinafter, referred to as syringe) has been provided as one of medical devices used for injection. As shown in  FIG. 6  and  FIG. 7 , a syringe  9  generally includes a barrel with needle  90  including a barrel body  92  configured to contain a formulation and an injection needle  91  with a proximal end  94  opening into the barrel body  92 , and a plunger  93  configured to expel the formulation contained in the barrel body  92  to the outside of the barrel with needle  90  through a distal end  96  of the injection needle  91  (Patent Literature 1). 
     In the barrel with needle  90 , the barrel body  92  has a cylindrical body wall  99 , and an end wall  98  closing one opening  993  of the body wall  99 . The end wall  98  includes an inner wall surface  981  located on the body wall  99  side, and the injection needle  91  is inserted and attached thereto. Thus, the barrel body  92  can contain the formulation. 
     The plunger  93  is formed into a rod shape with substantially the same outer diameter as the inner diameter of the body wall  99  so as to be movable in the axial direction of the body wall  99 . The plunger  93  is inserted into the barrel with needle  90  through the other opening  994  of the body wall  99 . 
     Thus, in the syringe  9  of this type, when the plunger  93  is pushed toward the injection needle  91  side, the formulation in an internal space A  1 . 0  defined by the barrel body  92  and the plunger  93  is expelled to the outside of the barrel with needle  90  through the distal end  96  of the injection needle  91 , following an increase in pressure in the internal space A. Thus, the formulation is injected to an injection target. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: WO2008/139982 
     Meanwhile, in the syringe  9  of this type, the inner wall surface  981  of the end wall  98  expands in the radial direction of the body wall  99  from an outer circumferential surface  95  of a proximal end part  941  of the injection needle  91  while curving toward the distal end  96  side of the injection needle  91  to form a recess. Therefore, the outer circumferential surface  95  of the injection needle  91  and the inner wall surface  981  of the end wall  98  form a recess Q recessed toward the distal end  96  side of the injection needle  91  along the outer circumferential surface  95  of the proximal end part  941  of the injection needle  91 . 
     Accordingly in the syringe  9  of this type, even if the plunger  93  is pushed into the barrel body  92  to the limit position of pushing, and the formulation contained in the barrel body  92  is expelled to the outside of the barrel with needle  90 , the formulation remains in the recess Q. 
     The syringe  9  used as a medical device is mostly discarded after the use as it is, and therefore in the syringe  9  of this type, the useful formulation is discarded without being injected. 
     SUMMARY 
     Technical Problem 
     In view of such an actual situation, it is therefore an object of the present invention to provide a barrel with needle that allows the formulation contained therein to be used without waste, and a syringe including the barrel with needle. 
     Solution to Problem 
     A barrel with needle according to the present invention includes: a barrel body defining an internal space configured to contain a formulation; and an injection needle with its proximal end opening into the internal space of the barrel body, wherein the barrel body includes: a cylindrical body wall; and an end wall closing one opening of the body wall and having an inner wall surface located on the body wall side, the injection needle is inserted and attached to the end wall, and the inner wall surface of the end wall expands in a radial direction of the body wall or in a direction intersecting an axial direction of the body wall and inclined toward the other opening side of the body wall, with any one of an outer circumferential edge, an inner circumferential edge, and a specific position between the outer circumferential edge and the inner circumferential edge on a proximal end surface of the injection needle serving as a starting point. 
     According to one embodiment of the present invention, the inner wall surface of the end wall may expand in a direction intersecting the axial direction of the body wall and inclined toward the other opening side of the body wall, from the inner circumferential edge or a specific position between the outer circumferential edge and the inner circumferential edge on the proximal end surface of the injection needle. 
     A syringe according to the present invention includes: the aforementioned barrel with needle; and a plunger configured to be inserted into the barrel with needle and to expel the formulation contained in the barrel body to the outside of the barrel with needle through a distal end of the injection needle. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of a syringe according to an embodiment of the present invention. 
         FIG. 2A  is an enlarged partial view of part α of the syringe according to the aforementioned embodiment in  FIG. 1 . 
         FIG. 2B  is an enlarged partial view of the syringe according to the aforementioned embodiment in  FIG. 2A . 
         FIG. 3A  is an enlarged partial view of part α of a syringe according to another embodiment in  FIG. 1 . 
         FIG. 3B  is an enlarged partial view of the syringe according to the aforementioned embodiment in  FIG. 3A . 
         FIG. 4A  is an enlarged partial view of part α of a syringe according to still another embodiment in  FIG. 1 . 
         FIG. 4B  is an enlarged partial view of the syringe according to the aforementioned embodiment in  FIG. 4A . 
         FIG. 5A  is a modification of the barrel with needle according to the present invention. 
         FIG. 5B  is another modification of the barrel with needle according to the present invention. 
         FIG. 5C  is a still another modification of the barrel with needle according to the present invention. 
         FIG. 6  is a front view of a conventional syringe. 
         FIG. 7  is an enlarged partial view of part β in  FIG. 6 . 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     A barrel with needle according to this embodiment includes: a barrel body defining an internal space configured to contain a formulation; and an injection needle with its proximal end opening into the internal space of the barrel body wherein the barrel body includes: a cylindrical body wall; and an end wall closing one opening of the body wall and having an inner wall surface located on the body wall side, the injection needle is inserted and attached to the end wall, and the inner wall surface of the end wall expands in a radial direction of the body wall or in a direction intersecting an axial direction of the body wall and inclined toward the other opening side of the body wall, with any one of an outer circumferential edge, an inner circumferential edge, and a specific position between the outer circumferential edge and the inner circumferential edge on a proximal end surface of the injection needle serving as a starting point. 
     In the barrel with needle with such a configuration, the inner wall surface of the end wall is not located more on the distal end side of the injection needle than the proximal end surface of the injection needle. Therefore, a recess recessed toward the distal end side of the injection needle is not formed along the outer circumferential surface of the proximal end part of the injection needle by the outer circumferential surface of the injection needle and the inner wall surface of the end wall. As a result, the formulation does not accumulate in the recess, and the formulation contained in the barrel body can be used without waste. 
     According to one embodiment of the present invention, the inner wall surface of the end wall may expand in a direction intersecting the axial direction of the body wall and inclined toward the other opening side of the body wall, from the inner circumferential edge or a specific position between the outer circumferential edge and the inner circumferential edge on the proximal end surface of the injection needle. 
     In the barrel with needle with such a configuration, the inner wall surface of the end wall can partially or entirely cover the proximal end surface of the injection needle. Therefore, even if the distal end of the injection needle is pierced into the injection target, and the injection needle is pressed toward the barrel body side, the inner wall surface of the end wall can receive the proximal end surface of the injection needle. Accordingly the barrel with needle with such a configuration can allow the injection needle to be firmly inserted and attached. 
     Further, since the inner wall surface of the end wall partially or entirely covers the proximal end surface of the injection needle, even if the formulation is pushed toward the injection needle side, the total pressure of the formulation is not applied to the proximal end surface of the injection needle. Accordingly, the barrel with needle with such a configuration has a strength that can sufficiently withstand the hydraulic pressure of the formulation since the proximal end surface of the injection needle is less likely to be pressed toward the distal end side of the injection needle. 
     A syringe according to the present invention includes: the aforementioned barrel with needle; and a plunger configured to be inserted into the barrel with needle and to expel the formulation contained in the barrel body to the outside of the barrel with needle through a distal end of the injection needle. 
     In the syringe with such a configuration, the inner wall surface of the end wall is not located more on the distal end side of the injection needle than the proximal end surface of the injection needle. Therefore, a recess recessed toward the distal end side of the injection needle is not formed along the outer circumferential surface of the proximal end part of the injection needle by the outer circumferential surface of the injection needle and the inner wall surface of the end wall. Accordingly, the formulation does not accumulate in the recess, and the formulation contained in the barrel body can be used without waste. 
     Further, in the syringe with such a configuration, the inner wall surface of the end wall can partially or entirely cover the proximal end surface of the injection needle. Therefore, even if the distal end of the injection needle is pierced into the injection target, and the injection needle is pressed toward the barrel body side, the inner wall surface of the end wall can receive the proximal end surface of the injection needle. Accordingly, the syringe with such a configuration can allow the injection needle to be firmly inserted and attached. 
     Further, since the inner wall surface of the end wall partially or entirely covers the proximal end surface of the injection needle, the total pressure of the formulation is not applied to the proximal end surface of the injection needle when the plunger expels the formulation from the barrel with needle. Accordingly the syringe with such a configuration has a strength that can sufficiently withstand the hydraulic pressure of the formulation since the proximal end surface of the injection needle is less likely to be pressed toward the distal end side of the injection needle. 
     As can be seen from the above, this embodiment can provide a barrel with needle and a syringe including the barrel with needle, in which the formulation contained therein can be used without waste. 
     Hereinafter, a syringe including a barrel with needle according to an embodiment of the present invention will be described with reference to the drawings. 
     As shown in  FIGS. 1 and 2 , the syringe including the barrel with needle according to this embodiment (hereinafter, referred to as syringe) includes a barrel with needle  2  including a barrel body  21  defining an internal space S configured to contain a formulation and an injection needle  22  with its proximal end  222  opening into the internal space S of the barrel body  21 , and a plunger  3  configured to be inserted into the barrel with needle  2  and to expel the formulation contained in the barrel body  21  to the outside of the barrel with needle  2  through a distal end  221  of the injection needle  22 . The syringe  1  further includes a cap (not shown) configured to cover the distal end  221  of the injection needle  22 . 
     The barrel with needle  2  further includes a needle fixing part  23  configured to fix the injection needle  22  at the distal end. 
     The barrel body  21  has a cylindrical body wall  201 , and an end wall  211  closing one opening  207  of the body wall  201 . The end wall  211  has an inner wall surface  213  located on the body wall  201  side, and the injection needle  22  is inserted and attached thereto. 
     The barrel body  21  is formed using a rigid material. The barrel body  21  is formed, for example, using a resin such as COP (cycloolefin polymer), COC (cycloolefin copolymer), PP (polypropylene), or PE (polyethylene), or a glass. 
     The body wall  201  is formed into a cylindrical shape. The body wall  201  is formed with a constant diameter from one end  203  to the other end  204 . The one opening  207  of the body wall  201  is closed by the end wall  211 , and the other opening  205  is open. Accordingly, the barrel body  21  has one end closed and the other end open, so that the plunger  3  can be inserted thereinto. 
     The end wall  211  is formed with a specific thickness so as to withstand the hydraulic pressure during injection. In the end wall  211 , an insertion hole  214  through which the injection needle  22  is inserted is formed. Accordingly, the end wall  211  is formed into an annular shape. The end wall  211  has a body  215  expanding from the insertion hole  214  toward the end edge of the end wall  211 , and an end edge part  216  forming the end edge. 
     The end wall  211  is formed into a tapered shape with the center of the insertion hole  214  serving as the starting point. Accordingly, the body  215  projects from the end edge part  216  in a direction in which the center line of the insertion hole  214  extends. Further, the end edge part  216  is formed into a substantially circular shape. Accordingly the inner wall surface  213  of the end wall  211  is an annular surface having an inner circumferential edge  213   a  and an outer circumferential edge  213   b.    
     The inner wall surface  213  of the end wall  211  expands in the radial direction of the body wall  201  or a direction intersecting the axial direction of the body wall  201  and inclined toward the other opening  205  side of the body wall  201 , with any one of an outer circumferential edge  223 , an inner circumferential edge  224 , and a specific position on a proximal end surface  225  of the injection needle  22  between the outer circumferential edge  223  and the inner circumferential edge  224  serving as a starting point. 
     The inner circumferential edge  213   a  of the inner wall surface  213  is located on the proximal end surface  225  of the injection needle  22 . Specifically, the inner circumferential edge  213   a  is located within a region including the outer circumferential edge  223  and the inner circumferential edge  224  on the proximal end surface  225  of the injection needle  22 . The outer circumferential edge  213   b  of the inner wall surface  213  is located at the same position as the inner circumferential edge  213   a  or is located more on the other opening  205  side of the body wall  201  than the inner circumferential edge  213   a , in the axial direction of the body wall  201 . Further, the inner wall surface  213  is located at the same position as the outer circumferential edge  223  of the injection needle  22  or is located more on the other opening  205  side of the body wall  201  than the outer circumferential edge  223 , in the axial direction of the body wall  201 . Thus, the inner wall surface  213  is not located more on the distal end  221  side of the injection needle  22  than the proximal end surface  225  of the injection needle  22 . 
     In this embodiment, the inner wall surface  213  of the end wall  211  expands in a direction intersecting the axial direction of the body wall  201  and inclined toward the other opening  205  side of the body wall  201 , from a specific position between the outer circumferential edge  223  and the inner circumferential edge  224  on the proximal end surface  225  of the injection needle  22 . 
     Specifically as shown in  FIG. 2A  and  FIG. 2B , the inner circumferential edge  213   a  of the inner wall surface  213  is located between the outer circumferential edge  223  and the inner circumferential edge  224  on the proximal end surface  225  of the injection needle  22 . Accordingly the inner wall surface  213  of the end wall  211  expands from the center of the proximal end surface  225  of the injection needle  22 . Thus, the inner wall surface  213  of the end wall  211  constitutes a supporting part  217  configured to support (receive) the proximal end surface  225  of the injection needle  22  in the body  215 . 
     The inner wall surface  213  of the end wall  211  constitutes a curved surface R extending from a connection point P with the injection needle  22  to a specific position. The curved surface R is curved radially inwardly of the insertion hole  214  of the end wall  211  to form a projection. Thereby the supporting part  217  is formed to be thick. The curved surface R has a specific radius of curvature. 
     The inner wall surface  213  of the end wall  211  constitutes a smooth surface from the inner circumferential edge  213   a  to the outer circumferential edge  213   b . That is, corners, projections, and the like are not formed on the inner wall surface  213  of the end wall  211 . 
     The injection needle  22  is formed into a cylindrical shape so as to allow the formulation to circulate therethrough. The injection needle  22  is formed with a constant inner diameter and a constant outer diameter from the distal end  221  to the proximal end  222 . The proximal end surface  225  of the injection needle  22  is constituted by a flat surface without unevenness from the outer circumferential edge  223  to the inner circumferential edge  224 . The proximal end surface  225  of the injection needle  22  is orthogonal to the axial direction of the injection needle  22 . 
     The injection needle  22  has the distal end  221  that is sharpened so as to be capable of piercing an injection target. The injection needle  22  is rigid. The injection needle  22  is formed, for example, by wire drawing of a steel tube made of stainless steel. Further, the injection needle  22  is formed, for example, using aluminum, aluminum alloy, titanium, titanium alloy, and other metals. 
     The injection needle  22  has a proximal end part inserted and attached into the insertion hole  214  of the end wall  211 . The injection needle  22  has an outer circumferential surface  226  in close contact with an inner circumferential surface  218  of the insertion hole  214 . The injection needle  22  has the distal end  221  projecting from the needle fixing part  23 . 
     The needle fixing part  23  is provided continuously with the end wall  211 . In the needle fixing part  23 , an insertion hole  231  into which the injection needle  22  is inserted and attached is formed. The needle fixing part  23  is provided continuously with the end wall  211  on the side on which the body  215  projects. 
     The needle fixing part  23  is arranged so that the center line of the insertion hole  231 , the center line of the insertion hole  214  of the end wall  211 , and the axis of the body wall  201  coincide with one another. The insertion hole  231  of the needle fixing part  23  has substantially the same diameter as the insertion hole  214  of the end wall  211 . The needle fixing part  23  of this embodiment is formed into a cylindrical shape. The needle fixing part  23  is formed with an outer diameter smaller than the outer diameter of the barrel body  21 . 
     The needle fixing part  23  fixes the injection needle  22  by bringing an inner circumferential surface  232  of the insertion hole  231  into contact with the outer circumferential surface  226  of the injection needle  22 . 
     The needle fixing part  23  is formed using a rigid material. The needle fixing part  23  is formed using the same material as the barrel body  21 . 
     The plunger  3  includes an expelling part  31  configured to be inserted into the barrel with needle  2  and to be slidable within the barrel body  21 , and a plunger body  32  having the expelling part  31  at the distal end. The plunger body  32  is formed into a rod shape. The plunger body  32  is formed to be longer than the barrel body  21 . That is, when the expelling part  31  is inserted into the barrel body  21  to the limit position of pushing, a proximal end part  321  of the plunger body  32  projects from the opening of the barrel body  21 . 
     The outer diameter of the expelling part  31  is formed to be substantially the same as the inner diameter of the body wall  201  of the barrel body  21 . The distal end of the expelling part  31  is formed in conformity with the shape of the inner wall surface  213  of the end wall  211 . That is, when the distal end of the plunger  3  is pushed into the barrel body  21  to the limit position of pushing, the distal end of the plunger  3  is fitted to the inner wall surface  213  of the end wall  211 . 
     Since the end wall  211  is formed into a tapered shape, the distal end of the plunger  3  of this embodiment is formed into the tapered shape. 
     As described above, the barrel with needle  2  according to this embodiment includes: a barrel body  21  defining an internal space S configured to contain a formulation; and an injection needle  22  with its proximal end  222  opening into the internal space S of the barrel body  21 , wherein the barrel body  21  includes: a cylindrical body wall  201 ; and an end wall  211  closing one opening  207  of the body wall  201  and having an inner wall surface  213  located on the body wall  201  side, the injection needle  22  is inserted and attached to the end wall  211 , and the inner wall surface  213  of the end wall  211  expands in a direction intersecting the axial direction of the body wall  201  and inclined toward the other opening  205  side of the body wall  201 , from an inner circumferential edge  224  or a specific position between an outer circumferential edge  223  and the inner circumferential edge  224  on a proximal end surface  225  of the injection needle  22 . 
     The syringe  1  according to this embodiment includes: the barrel with needle  2 ; and a plunger  3  configured to be inserted into the barrel with needle  2  and to expel the formulation contained in the barrel body  21  to the outside of the barrel with needle  2  through a distal end  221  of the injection needle  22 . 
     According to the aforementioned configuration, the inner wall surface  213  of the end wall  211  is not located more on the distal end  221  side of the injection needle  22  than the proximal end surface  225  of the injection needle  22 . Therefore, a recess recessed toward the distal end  221  side of the injection needle  22  is not formed along the outer circumferential surface  226  of the proximal end part of the injection needle  22  by the outer circumferential surface  226  of the injection needle  22  and the inner wall surface  213  of the end wall  211 . As a result, the formulation does not accumulate in the recess, and the formulation contained in the barrel body  21  can be used without waste. 
     Further, the inner wall surface  213  of the end wall  211  can partially or entirely cover the proximal end surface  225  of the injection needle  22 . Therefore, even if the distal end  221  of the injection needle  22  is pierced into the injection target, and the injection needle  22  is pressed toward the barrel body  21  side, the inner wall surface  213  of the end wall  211  can receive the proximal end surface  225  of the injection needle  22 . Accordingly, the aforementioned configuration can allow the injection needle  22  to be firmly inserted and attached. 
     Further, since the inner wall surface  213  of the end wall  211  partially or entirely covers the proximal end surface  225  of the injection needle  22 , even if the formulation is pushed toward the injection needle  22  side, the total pressure of the formulation is not applied to the proximal end surface  225  of the injection needle  22  (when the plunger  3  expels the formulation from the barrel with needle  2 ). Accordingly the aforementioned configuration gives a strength that can sufficiently withstand the hydraulic pressure of the formulation since the proximal end surface  225  of the injection needle  22  is less likely to be pressed toward the distal end  221  side of the injection needle  22 . 
     According to the aforementioned configuration, the inner wall surface  213  of the end wall  211  expands with any one of the outer circumferential edge  223 , the inner circumferential edge  224 , and a specific position between the outer circumferential edge  223  and the inner circumferential edge  224  on the proximal end surface  225  of the injection needle  22  serving as a starting point, and therefore the proximal end part of the injection needle  22  is not exposed to the internal space S. Therefore, even if impurities such as oils adhere onto the outer circumferential surface  226  of the injection needle  22  when forming the injection needle  22 , such impurities are not entrained into the formulation. Accordingly injection of such impurities to the injection target together with the formulation can be prevented. 
     Further, since the proximal end part of the injection needle  22  is not exposed to the internal space S, the hydraulic pressure of the formulation is not applied to the outer circumferential surface  226  of the injection needle  22  when the plunger  3  expels the formulation to the outside of the barrel with needle  2 . Accordingly breaking and cracking are less likely to occur in the injection needle  22 . 
     According to the aforementioned configuration, the inner wall surface  213  of the end wall  211  is not located more on the distal end  221  side of the injection needle  22  than the proximal end surface  225  of the injection needle  22 . Therefore, the flow of the formulation is less likely to be disturbed on the proximal end surface  225  of the injection needle  22  when the formulation is expelled from the barrel body  21 . Specifically, a recess recessed toward the distal end  221  side of the injection needle  22  is not formed along the outer circumferential surface  226  of the proximal end part of the injection needle  22 , and therefore the formulation does not enter the recess. Accordingly when the formulation is expelled from the barrel body  21 , there is no formulation flowing out around the recess, and therefore the formulation can be rectified. Following this, during the expelling from the barrel with needle  2 , the resistance in the plunger  3  can be reduced. 
     According to the aforementioned configuration, the supporting part  217  is formed to be thick, and therefore the strength of the supporting part  217  is increased. Accordingly the syringe  1  with the aforementioned configuration allows the injection needle  22  to be firmly inserted and attached. 
     According to the aforementioned configuration, the distal end of the expelling part  31  of the plunger  3  is formed in conformity with the shape of the inner wall surface  213  of the end wall  211 . Therefore, when the plunger  3  is inserted into the barrel body  21  to be pushed into the barrel body  21  to the limit position of pushing, most of the formulation contained in the barrel body  21  can be expelled to the outside of the barrel with needle  2 . 
     The barrel with needle  2  and the syringe  1  of the present invention are not limited to the aforementioned embodiment. Further, the barrel with needle  2  and the syringe  1  according to the present invention are not limited to the aforementioned operational effects. In the barrel with needle  2  and the syringe  1  according to the present invention, various modifications can of course be made without departing from the gist of the present invention. 
     In the aforementioned embodiment, there is no particular mention of the methods for forming the barrel with needle  2  and the syringe  1 , the barrel with needle  2  and the syringe  1  according to the present invention can be formed by insert molding by integrally injection-molding the injection needle  22 , the needle fixing part  23 , and the barrel body  21 . Further, the barrel with needle  2  and the syringe  1  according to the present invention can be formed also by a method of integrally injection-molding the needle fixing part  23  and the barrel body  21  in advance, thereafter inserting the injection needle  22  into the needle fixing part  23 , and fixing the injection needle  22  and the needle fixing part  23  together with an adhesive or by heat welding. 
     In the case of integrally forming the injection needle  22 , the needle fixing part  23 , and the barrel body  21  together by insert molding, a gap is less likely to be formed between the injection needle  22  and the needle fixing part  23 . That is, in insert molding, the barrel with needle  2  is formed by allowing a resin or the like to flow around the outer circumferential surface  226  of the injection needle  22 , and therefore it is possible to allow the outer circumferential surface  226  of the injection needle  22  to be in close contact with the inner circumferential surface  232  of the insertion hole  231  formed in the needle fixing part  23 . Therefore, the formulation does not accumulate between the injection needle  22  and the needle fixing part  23 , and the formulation does not remain between the injection needle  22  and the needle fixing part  23 . Accordingly, in the aforementioned case, the formulation contained in the barrel body can be used without waste. Further, when the formulation is expelled from the barrel body  21 , there is no formulation flowing out not only around the recess but also around the gap between the injection needle  22  and the needle fixing part  23 , and therefore the formulation can be rectified during the injection. 
     In the aforementioned embodiment, the case where the inner wall surface  213  of the end wall  211  expands from the center of the proximal end surface  225  of the injection needle  22  has been described, but there is no limitation to this. As shown in  FIG. 4A  and  FIG. 4B , the inner wall surface  213  of the end wall  211  may expand from the outer circumferential edge  223  of the injection needle  22 . 
     Further, as shown in  FIG. 3A  and  FIG. 3B , the inner wall surface  213  of the end wall  211  may expand from the inner circumferential edge  224  of the injection needle  22  toward an inner wall surface  202  of the body wall  201 . In this case, the entire region of the proximal end surface  225  of the injection needle  22  is covered by the inner wall surface  213  of the end wall  211 . Accordingly the barrel with needle  2  can allow the injection needle  22  to be inserted and attached more firmly. 
     In the aforementioned embodiment, the inner wall surface  213  of the end wall  211  is formed to be substantially flat from the inner circumferential edge  213   a  to the outer circumferential edge  213   b , but there is no limitation to this. The inner wall surface  213  may be curved in the radial direction of the body wall  201  to be concave or convex. That is, the inner wall surface  213  of the end wall  211  may be an arcuate surface extending from the inner circumferential edge  213   a  to the outer circumferential edge  213   b.    
     In the aforementioned embodiment, the case where the inner wall surface  213  of the end wall  211  expands in a direction intersecting the axial direction of the body wall  201  and inclined toward the other opening  205  side of the body wall  201  from a specific position between the outer circumferential edge  223  and the inner circumferential edge  224  has been described, but there is no limitation to this. The inner wall surface  213  of the end wall  211  may expand in the radial direction of the body wall  201 . Further, as shown in  FIG. 4A  and  FIG. 4B , the inner wall surface  213  of the end wall  211  may partially expand in the radial direction of the body wall  201  and expand continuously therewith in a direction intersecting the axial direction of the body wall  201  and inclined toward the other opening  205  side of the body wall  201 . 
     In the aforementioned embodiment, the case where the end wall  211  is formed into a tapered shape has been described, but there is no limitation to this. For example, the end wall  211  may be formed stepwise. Further, it may have an uneven surface. 
     Further, the end edge of the end wall  211  may be elliptical, triangular quadrangular, or the like. Following this, the body wall  201  may be formed into elliptical, triangular, and quadrangular cylindrical shapes and the like, corresponding to the shape of the end edge part  216  of the end wall  211 . 
     In the aforementioned embodiment, the case where the inner wall surface  213  of the end wall  211  constitutes the curved surface R from the connection point P with the injection needle  22  to the specific position has been described, but there is no limitation to this. As shown in  FIG. 5A  to  FIG. 5C , the inner wall surface  213  of the end wall  211  may be formed straight from the connection point P with the injection needle  22  to the inner wall surface  202  of the body wall  201 . 
     In the aforementioned embodiment, the case where the proximal end surface  225  of the injection needle  22  is constituted by a flat surface without unevenness has been described, but there is no limitation to this. The proximal end surface  225  of the injection needle  22  may be a convex surface projecting toward the other end  204  side of the body wall  201  or may be a concave surface recessed toward the distal end  221  side. Further, the proximal end surface  225  may be an uneven surface. 
     In the aforementioned embodiment, the case where the injection needle  22  is formed with a constant inner diameter and a constant outer diameter from the distal end  221  to the proximal end  222  has been described, but there is no limitation to this. The injection needle  22  may be tapered to have a larger diameter in the proximal end part than in the distal end part. Further, the injection needle  22  is not limited to one having a cylindrical shape, and may have a polygonal sectional shape such as a triangular shape. 
     In the aforementioned embodiment, there is no particular mention of the shape of the outer circumferential surface  226  of the injection needle  22 , but the outer circumferential surface  226  of the injection needle  22  may be provided with a rib or a groove or may be provided with an uneven part formed by blasting. The uneven part may be formed from the proximal end surface  225  or may be formed from a position away from the proximal end surface  225  on the distal end  221  side. 
     In the aforementioned embodiment, the case where the end wall  211  is formed into a tapered shape, and therefore the distal end of the plunger  3  is formed into the tapered shape has been described, but there is no limitation to this. The distal end of the plunger  3  needs only to be formed in conformity with the shape of the inner wall surface  213  of the end wall  211 . In the case where the end wall  211  is formed into a plate shape, and the inner wall surface  213  is not inclined toward the other opening  205  side of the body wall  201 , it may be formed flat, accordingly. 
     REFERENCE SIGNS LIST 
     
         
           1 : Syringe 
           2 : Barrel with needle 
           21 : Barrel body 
           201 : Body wall 
           202 : Inner wall surface 
           203 : One end 
           204 : The other end 
           211 : End wall 
           213 : Inner wall surface 
           213   a : Inner circumferential edge 
           213   b : Outer circumferential edge 
           214 : Insertion hole 
           215 : Body 
           216 : End edge part 
           217 : Supporting part 
           218 : Inner circumferential surface 
           22 : Injection needle 
           221 : Distal end 
           222 : Proximal end 
           223 : Outer circumferential edge 
           224 : Inner circumferential edge 
           225 : Proximal end surface 
           226 : Outer circumferential surface 
           23 : Needle fixing part 
           231 : Insertion hole 
           232 : Inner circumferential surface 
           3 : Plunger 
           31 : Expelling part 
           32 : Plunger body 
         P: Connection point 
         S: Internal space 
         R: Curved surface