Syringe assembly and filling method

Abstract

The application discloses a syringe assembly and a filling method. The syringe assembly comprises a straight needle tube, an injection cavity is formed in the straight needle tube, the injection cavity is open through a first opening arranged at one end of the straight needle tube, and an outlet bypass is formed on the inner wall of the injection cavity and adjacent to the first opening. A top piston is arranged at the first opening, and the top piston can move relative to the straight needle tube. After the top piston moves to a first opening degree position and a second opening degree position, at least part of the top piston is staggered with the outlet bypass to keep the outlet bypass open at the first opening degree position, and at least part of the top piston is accommodated in the injection cavity and the outlet bypass is closed at the second opening degree position. The syringe assembly of the application can complete freeze-drying in the syringe, can be sealed after freeze-drying, effectively prevents environmental pollution, and can meet the process requirements of freeze-drying.

Description

Technical Field

[0001] This invention relates to the field of syringes, and more particularly to a syringe assembly and filling method. Background Technology

[0002] In related technologies, injectable solutions are difficult to preserve stably for long periods in solution form, and are often converted into lyophilized powders using a vacuum freeze-drying process. However, traditional syringes are not compatible with the freeze-drying process, requiring the lyophilized powder to be loaded into the syringe, which poses a risk of contamination during transport. Traditional syringes cannot meet the requirements of the freeze-drying process. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, one object of this invention is to provide a syringe assembly that enables freeze-drying to be completed inside the syringe, and can be sealed after freeze-drying, effectively preventing environmental pollution, while the injection chamber can meet the process requirements of freeze-drying.

[0004] This application also proposes a filling method for the above-mentioned syringe assembly.

[0005] The syringe assembly according to this application includes: a straight needle tube having an injection chamber formed therein, the injection chamber being open through a first opening at one end of the straight needle tube, and an outlet bypass forming on the inner wall of the injection chamber adjacent to the first opening; and a top piston disposed at the first opening, the top piston being movable relative to the straight needle tube, and moving to a first opening position and a second opening position after the top piston is moved, wherein at least a portion of the top piston intersects with the outlet bypass to keep the outlet bypass open, and at least a portion of the top piston is received within the injection chamber and closes the outlet bypass in the second opening position.

[0006] According to the syringe assembly of this application, the top piston is designed to maintain the injection chamber in communication with the outside during the freeze-drying process. After freeze-drying, the top piston is used to close the injection chamber to maintain its sealed state. During subsequent injection, the top piston can still be actuated to open the outlet bypass to allow the syringe assembly to perform the injection process. The syringe assembly of this application only needs to be designed with a top piston, which takes into account the freeze-drying process of the syringe assembly without affecting the subsequent injection process, and reduces external environmental pollution.

[0007] According to some embodiments of this application, at least a portion of the inner wall of the injection chamber is recessed to form the outlet bypass, and at least a portion of the inner wall of the injection chamber is configured as an abutment wall, the abutment wall being located on the outer periphery of the outlet bypass; the top piston is actuated to the second opening position, and at least a portion of the outer peripheral wall of the top piston abuts against the abutment wall to close the outlet bypass.

[0008] According to some embodiments of this application, the outlet bypass extends along the generatrix of the straight-through needle, and a seal is formed on the outer periphery of the top piston for contacting the abutment wall. In a first opening position, the seal is staggered with the outlet bypass to keep the outlet bypass open, and in a second opening position, the seal contacts the abutment wall and separates the outlet bypass from the injection chamber.

[0009] According to some embodiments of this application, the syringe assembly further includes: a locking cap assembly, which is disposed at the end of the straight needle tube and covers the outer periphery of the first opening, and the locking cap assembly is provided with a drug outlet; wherein after the top piston moves to the first opening position, a piston cavity communicating with the outlet bypass is formed between the top piston and the locking cap assembly, and the drug liquid is communicated to the drug outlet through the piston cavity.

[0010] According to some embodiments of this application, a protruding protrusion is formed on at least one of the top end face of the top piston and the bottom end face of the locking cover assembly. When the top piston moves to a first opening position, the protrusion abuts against the top end face of the top piston or the bottom end face of the locking cover assembly to maintain the piston cavity formed between the top end face of the top piston and the bottom end face of the locking cover assembly.

[0011] According to some embodiments of this application, the locking cap assembly includes: a locking cap body, the locking cap body forming a receiving cavity and covering the end of the through needle tube, and a first locking engagement member formed on the locking cap body; a Luer cone, the Luer cone being disposed on the locking cap body and forming a drug dispensing channel communicating with the receiving cavity; and a Luer lock cap, the Luer lock cap being provided with a second locking engagement member, the Luer lock cap covering the Luer cone and being locked to the first locking engagement member by the second locking engagement member.

[0012] According to some embodiments of this application, the syringe assembly further includes: an injection device that can replace the Luer lock cap on the lock cover body, and the injection device is provided with a third locking engagement member that is detachably connected to the first locking engagement member.

[0013] According to some embodiments of this application, the other end of the straight needle tube is provided with a second opening; the injection chamber assembly further includes: a middle piston and a bottom piston, the middle piston being disposed in the injection chamber and located above the bottom piston and dividing the injection chamber into a first chamber and a second chamber, the bottom piston being close to the second opening; the first chamber communicating with the first opening and adapted to contain liquid drugs or powder media, the second chamber being adapted to contain liquid media, and the first chamber and the second chamber being selectively connected.

[0014] According to some embodiments of this application, the inner wall of the injection cavity is formed with a recessed inner flow channel, the central piston is movable to the inner flow channel, and the outer peripheral wall of the central piston is spaced apart from the inner wall of the inner flow channel to form a gap that connects the first cavity and the second cavity.

[0015] The following is a brief description of a filling method for a syringe assembly used in any of the above embodiments.

[0016] The filling method includes: filling a first cavity with liquid medication through a first opening and installing a top piston; adjusting the top piston to a first opening position and then performing vacuum freeze-drying on the inside of the straight-through syringe; and closing the first opening by moving the top piston from the first opening position to a second opening position after the vacuum freeze-drying operation is completed. The filling method of this application has low process complexity in vacuum freeze-drying liquid medication, eliminates the need for additional locking cap structures, and the top piston is compatible with other locking cap assemblies, eliminating the need to remove the top piston.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of a syringe structure according to an embodiment of this application;

[0020] Figure 2 This is a schematic diagram of the structure of a straight-through needle according to an embodiment of this application;

[0021] Figure 3 This is a schematic diagram of the bottom piston according to an embodiment of this application;

[0022] Figure 4 This is a schematic diagram of the structure of the central piston according to an embodiment of this application;

[0023] Figure 5 This is a schematic diagram of the top piston according to an embodiment of this application;

[0024] Figure 6 This is a schematic diagram of the structure of a lock cover body according to an embodiment of this application;

[0025] Figure 7 This is a schematic diagram of the structure of a booster according to an embodiment of this application;

[0026] Figure 8 This is a schematic diagram of the piston push rod according to an embodiment of this application;

[0027] Figure 9 This is a schematic diagram of the operation of the top piston according to an embodiment of this application;

[0028] Figure 10 This is a schematic diagram of the engagement between the locking cover body and the top piston according to an embodiment of this application;

[0029] Figure 11 This is a schematic diagram of a structure in which a protrusion is provided on the top piston according to an embodiment of this application;

[0030] Figure 12 This is a schematic diagram of a structure in which a protrusion is provided on the top piston according to another embodiment of this application;

[0031] Figure 13 This is a filling schematic diagram of a syringe assembly according to an embodiment of this application.

[0032] Figure label:

[0033] Syringe assembly 100;

[0034] Straight needle tube 1, needle tube outer wall 101, needle tube inner wall 102, inner flow channel 103, bottom groove 104, bottom guide slope 105, bottom end face 106, top end face 107, top guide slope 108, top inner flow channel 109;

[0035] Bottom piston 2, waterproof line 201, internal thread 202, top protrusion 203, bottom boss 204

[0036] 3. Middle piston, 301. Waterproof line, 302. End face protrusion.

[0037] Top piston 4, waterproof line 401, end face boss 402

[0038] Locking cap assembly 5, guide bevel 501, annular clamp 502, sealing concave flange 503, piston inner cavity 504, Luer cone 505, medicine outlet 506, Luer lock thread 507, inner cavity protrusion 508;

[0039] Ruhr lock cap 6,

[0040] Booster 7, claw 701, slot 702, deformation cavity 703, outer contour 704;

[0041] Piston push rod 8, flange 801, rod body 802, external thread 803, reinforcing rib 804. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0043] The following is for reference. Figures 1-12 The syringe assembly 100 according to an embodiment of the present invention includes a straight needle tube 1 and a top piston 4. An injection chamber is formed in the straight needle tube 1 and is opened through a first opening provided at one end of the straight needle tube 1. An outlet bypass is formed on the inner wall of the injection chamber adjacent to the first opening. The top piston 4 is disposed at the first opening and is movable relative to the straight needle tube 1. After the top piston 4 is moved, it moves to a first opening position and a second opening position. In the first opening position, at least a portion of the top piston 4 is intersected with the outlet bypass to keep the outlet bypass open. In the second opening position, at least a portion of the top piston 4 is received in the injection chamber and closes the outlet bypass.

[0044] According to the syringe assembly 100 of this application, the injection chamber can be used to contain the drug to be lyophilized. The outlet bypass provided on the straight needle tube 1 is used to allow the gas in the injection chamber to be discharged through the outlet bypass during the lyophilization process. The liquid drug generates sublimation gas in the vacuum freeze-drying process, and the gas is discharged through the outlet bypass, so that the liquid drug can be converted into lyophilized powder through the vacuum freeze-drying process.

[0045] By setting the top piston 4, in the first opening position, the top piston 4 is staggered with the outlet bypass, allowing the top piston 4 to connect the injection chamber with the external airflow, enabling the syringe assembly 100 to freeze-dry the liquid drug in the injection chamber, thus realizing the freeze-drying process. The second opening position allows the syringe assembly 100 to be completely sealed from the external space, ensuring that the freeze-dried powder is isolated from the outside environment and preventing drug contamination after the freeze-drying process is completed. During subsequent injection, the freeze-dried powder dissolves in the injection chamber, and the top piston 4 can still move. After moving, it moves from the second opening position to the first opening position, allowing the injection chamber to connect with the outside through the outlet bypass for further injection.

[0046] According to the syringe assembly 100 of this application, the top piston 4 is positioned to satisfy the requirement of maintaining the injection chamber in communication with the outside during the freeze-drying process. After freeze-drying, the top piston 4 is used to close the injection chamber to maintain its sealed state. In subsequent injection processes, the top piston 4 can still be moved to open the outlet bypass so that the syringe assembly 100 can perform the injection process. The syringe assembly 100 of this application only needs to be set with a top piston 4, which takes into account the freeze-drying process of the syringe assembly 100 without affecting the subsequent injection process, reducing external environmental pollution. The action of the top piston 4 on the syringe assembly 100 corresponds to the process flow, simplifying the structure and eliminating the need to adjust the original structural form.

[0047] According to some embodiments of this application, an outer wall 101 is formed on the outer periphery of the straight needle tube 1, and an inner wall 102 is formed inside the straight needle tube 1. At least a portion of the inner wall 102 of the injection chamber is recessed to form an outlet bypass. At least a portion of the inner wall of the injection chamber is constructed as an abutment wall, and the abutment wall is located on the outer periphery of the outlet bypass. The top piston 4 is actuated to the second opening position, and at least a portion of the outer peripheral wall of the top piston 4 abuts against the abutment wall to close the outlet bypass.

[0048] The outlet bypass is constructed as a top inner flow channel 109 recessed in the inner wall of the injection chamber. The top piston 4 remains in contact with the inner wall of the injection chamber during its movement within the injection chamber. A space is formed inside the top inner flow channel 109 that is spaced apart from the outer peripheral wall of the top piston 4. This space extends to the first opening position of the injection chamber to form the aforementioned outlet bypass.

[0049] The top inner flow channel 109 is radially open, maintaining radial communication with the injection chamber. When the top piston 4 moves to completely overlap with the groove radially, the top piston 4 closes the groove. At this time, the top piston 4 remains in the second opening position, using the contact between the top piston 4 and the inner wall of the injection chamber surrounding the groove to completely close the outlet bypass. Therefore, the injection chamber cannot communicate with the outside through the outlet bypass. When the top piston 4 moves to a position where it intersects with the opening direction of the groove, the opening direction of the groove no longer overlaps with the top piston 4, and the injection chamber can then communicate with the outside through the outlet bypass.

[0050] According to one embodiment of this application, the outlet bypass extends along the generatrix of the straight-through needle tube 1, and a seal for contacting the wall is formed on the outer periphery of the top piston 4. In a first opening position, the seal is staggered with the outlet bypass to keep the outlet bypass open, and in a second opening position, the seal contacts the wall and separates the outlet bypass from the injection chamber.

[0051] By extending the outlet bypass along the busbar direction, the outlet bypass can be extended in a straight line to maintain smooth flow, reduce flow resistance, and increase the flow velocity of liquid and gas within the outlet bypass. In some embodiments, multiple outlet bypasses are provided in the injection chamber at circumferential intervals. Multiple outlet bypasses can be used to increase the total flow area to improve the flow rate of gas and liquid.

[0052] A seal formed on the outer periphery of the top piston 4 is used to fit against the inner wall of the injection chamber. When the top piston 4 is in the first open position, the seal abuts against the wall portion surrounding the groove structure. An outlet bypass forms an outlet communicating with the injection chamber at a position staggered from the seal, thus connecting the injection chamber to the first opening. In the second open position, the top piston 4 abuts against the wall surrounding the groove structure, completely surrounding the opening of the groove, thus completely disconnecting the outlet bypass from the injection chamber and separating them.

[0053] By setting a seal on the outer periphery of the top piston 4, the contact between the top piston 4 and the inner wall of the injection chamber is made tighter, which improves the sealing effect of the corresponding outlet bypass and effectively prevents environmental pollutants from entering the injection chamber.

[0054] In some embodiments of this application, the seal may be configured as a raised sealing rib formed on the outer periphery of the top piston 4, which can maintain the interference between the top piston 4 and the inner wall of the injection chamber.

[0055] In some embodiments of this application, the length of the seal is greater than the length of the outlet bypass, which extends along the generatrix direction. The top piston 4 is constructed in a columnar shape, and the seal is located on the outer periphery of the top piston 4 and also extends along the generatrix direction of the top piston 4. The seal is used to close the radial opening of the groove. The length of the seal in the generatrix direction of the top piston 4 is greater than the length of the outlet bypass, so that the second opening position of the top piston 4 has a large range of movement within the injection chamber, while still maintaining the closure of the outlet bypass.

[0056] In some embodiments, the seal may be configured as a rectangular protrusion protruding from the outer periphery of the top piston 4, the width of which is greater than the width of the outlet bypass.

[0057] In some embodiments, the seal may be configured as a strip protrusion protruding from the top inner piston, the strip protrusion extending around the edge of a rectangle, the width of which is greater than the width of the outlet bypass, the strip protrusion surrounding the edge of a groove, and the strip protrusion also achieving a complete seal on the outlet bypass after the top piston 4 moves to the second opening position.

[0058] In some embodiments, the syringe assembly 100 further includes a locking cap assembly 5, which is disposed at the end of the straight needle tube 1 and covers the outer periphery of the first opening. The locking cap assembly 5 is provided with a drug outlet 506. After the top piston 4 moves to the first opening position, a piston cavity 504 communicating with the outlet bypass is formed between the top piston 4 and the locking cap assembly 5, and the drug solution is communicated to the drug outlet 506 through the piston cavity 504.

[0059] The locking cap assembly 5 is fitted over the end of the straight needle tube 1. The locking cap assembly 5 can be used to further seal the straight needle tube 1. At the same time, the locking cap assembly 5 can serve as a connection end for injection or infusion. The drug outlet 506 provided on the locking cap assembly 5 can discharge the drug solution. The locking cap assembly 5 can be used to match the syringe needle or other injection device.

[0060] During injection, the top piston 4 can move under the internal pressure of the injection chamber or driven by other pushing devices. After the top piston 4 moves back to the first opening position, the outlet bypass opens, and the top piston 4 moves towards the first opening and enters the locking cap assembly 5. A piston cavity 504 communicating with the outlet bypass is formed between the locking cap assembly 5 and the top piston 4. The piston cavity 504 connects the injection chamber and the drug outlet 506 through the outlet bypass. In the injection chamber assembly of this application, the top piston 4 does not affect the conduction of the drug solution during the injection process, and the piston cavity 504 still maintains the flow of the drug solution.

[0061] In some embodiments, a protruding protrusion is formed on at least one of the top end face 107 of the top piston 4 and the bottom end face 106 of the locking cover assembly 5. When the top piston 4 moves to a first opening position, the protrusion abuts against the top end face 107 of the top piston 4 or the bottom end face 106 of the locking cover assembly 5 to maintain a piston cavity 504 between the top end face 107 of the top piston 4 and the bottom end face 106 of the locking cover assembly 5.

[0062] After the top piston 4 moves to the first opening position, in order to avoid complete contact between the top end face 107 of the top piston 4 and the bottom end face 106 of the locking cap assembly 5, a protrusion is provided to maintain a certain gap between the top end face 107 of the top piston 4 and the bottom end face 106 of the locking cap assembly 5 at any position for the flow of the medicine.

[0063] In some embodiments, the protrusion is configured such that an inner cavity protrusion 508 is formed on the bottom end face 106 of the locking cover assembly 5.

[0064] like Figure 11 , 12As shown, the protrusion can be constructed as an end face protrusion 402 surrounding the medicine outlet 506. The end face protrusion 402 is constructed as multiple arc segments, with adjacent arc segments spaced apart to reserve a passage for the flow of medicine liquid.

[0065] In some embodiments of this application, the locking cap assembly 5 includes a locking cap body, a Luer cone 505, and a Luer lock cap 6. The locking cap body forms a receiving cavity and covers the end of the straight needle tube 1. A first locking fitting is formed on the inner surface of the locking cap body. The Luer cone 505 is disposed on the locking cap body and forms a drug dispensing channel communicating with the receiving cavity. A drug outlet 506 is provided on the locking cap body, and the drug dispensing channel communicates with the drug outlet 506. The Luer lock cap 6 is provided with a second locking fitting, and the Luer lock cap 6 covers the Luer cone 505 and is locked with the first locking fitting through the second locking fitting.

[0066] The receiving cavity of the locking cover body is located at one end of the straight needle tube 1. A certain space is left between the internal receiving cavity and the end of the straight needle tube 1 to serve as the piston cavity 504. When the top piston 4 moves to the first opening position, at least part of the top piston 4 is received in the receiving cavity.

[0067] The first locking engagement member provided on the lock cover body can be constructed as a sleeve structure surrounding the outer periphery of the Luer cone 505, with a Luer lock thread 507 provided inside the sleeve structure, while the second locking engagement member on the outer periphery of the Luer lock cap 6 is constructed as an external thread for engaging with the Luer lock thread 507 inside the sleeve.

[0068] According to some embodiments of this application, the syringe assembly 100 further includes an injection device that can alternatively mount the Luer lock cap 6 to the lock cover body. The injection device is provided with a third locking engagement member that is detachably connected to the first locking engagement member. The third locking engagement member on the injection device can be configured with an external thread, which engages with the Luer lock thread 507 to achieve a detachable connection with the lock cover body.

[0069] According to some embodiments of this application, the other end of the straight needle tube 1 is provided with a second opening; the injection chamber assembly further includes: a middle piston 3 and a bottom piston 2, the middle piston 3 is disposed in the injection chamber and located above the bottom piston 2 and divides the injection chamber into a first chamber and a second chamber, the bottom piston 2 is close to the second opening; the first chamber is in communication with the first opening and is adapted to contain liquid drugs or powder media, the second chamber is adapted to contain liquid media, and the first chamber and the second chamber are selectively in communication.

[0070] An injection chamber is formed inside the straight-through needle tube 1. The inner wall 102 of the injection chamber has a closed section and a through section. A middle piston 3 is disposed within the injection chamber and defines a first cavity between itself and the front cavity of the injection chamber. A bottom piston 2 is disposed at the bottom of the injection chamber and defines a second cavity between itself and the middle piston 3. The first and second cavities are used to accommodate two different mixtures to be prepared. By placing the two different mixtures to be prepared in the first and second cavities, the drug can be effectively preserved.

[0071] An inner flow channel 103 is formed in the through-tube section. The middle piston 3 moves within the straight needle tube 1 to selectively move to cooperate with the through-tube section or with the closed tube section. The bottom piston 2 can selectively move toward the middle piston 3. The pressure of the bottom piston 2 pushes the middle piston 3 from the closed tube section to the through-tube section. When the middle piston 3 moves to the through-tube section, the bottom piston 2 approaches the middle piston 3, causing the volume of the second cavity to gradually decrease.

[0072] In this application, in the initial state, the middle piston 3 is in contact with the closed tube section, and the first cavity and the second cavity remain sealed. During the process of pushing the bottom piston 2, since the second cavity remains closed, the pressure is transmitted to the middle piston 3 through the action of air pressure or hydraulic pressure to drive the middle piston 3 to move, so that the middle piston 3 cooperates with the connecting tube section, thereby using the internal flow channel 103 provided on the connecting tube section to connect the first cavity and the second cavity. The two different mixtures located in the first cavity and the second cavity are fully mixed to form a prepared drug for injection.

[0073] After the middle piston 3 moves to the mating tube section, the pressure inside the second chamber changes because it is connected to the first chamber through the internal flow channel 103. Under the continuous action of the bottom piston 2, the volume of the second chamber gradually decreases until the bottom piston 2 and the middle piston 3 come into contact, thus completely mixing the media in the first and second chambers. Further pushing the bottom piston 2 will drive the middle piston 3 to move, pushing the mixed drug in the first chamber and injecting it.

[0074] In this application, by setting the middle piston 3 and the bottom piston 2, and under the action of the inner flow channel 103, the mixture to be mixed in the first chamber and the second chamber can be completely mixed. The two different mixtures can correspond to the drug and the solvent respectively. On the one hand, it reduces the contamination during the mixing process. On the other hand, the syringe of this application does not need to carry excessive solvent, and the dosage control of the solvent is more precise. After the bottom piston 2 and the middle piston 3 stop, the medium to be mixed in the second chamber will completely enter the first chamber through the inner flow channel 103. In large batches of drugs, reducing the excessive filling dosage of a single syringe assembly 100 can reduce the overall cost and reduce unnecessary waste.

[0075] According to some embodiments of this application, a first stop surface is formed at the bottom of the middle piston 3, and a second stop surface is formed at the top of the bottom piston 2. The bottom piston 2 moves toward the middle piston 3 until the first stop surface contacts the second stop surface, thus introducing the second chamber medium into the first chamber. The bottom of the middle piston 3 and the top of the bottom piston 2 are respectively provided with a first stop surface and a second stop surface. The stop surface between the first stop surface and the second stop surface compresses all the agent in the second chamber into the first chamber, thereby discharging all the mixture to be mixed in the first and second chambers, further improving the accuracy of agent control.

[0076] In some embodiments, the face-to-face contact between the first stop surface and the second stop surface can be understood as complete contact between the first stop surface and the second stop surface, reducing the space of the second cavity to a state with almost no space, thereby squeezing the mixture to be mixed in the second cavity into the first cavity. Through the face-to-face contact between the first stop surface and the second stop surface, the mixture to be mixed in the second cavity can be fully introduced into the first cavity. Therefore, the syringe assembly 100 of this application greatly reduces the overfilling dosage of the mixture to be mixed in the second cavity, thereby reducing the cost.

[0077] In some embodiments of this application, the first and second abutment surfaces are constructed as flat walls perpendicular to the extension direction of the injection cavity. Setting the first and second abutment surfaces as flat walls allows for sufficient contact between them, reducing the gap between them after abutment, minimizing the residual amount of the mixture in the second cavity, and helping to reduce the amount of overfilled drug. Simultaneously, constructing the first and second abutment surfaces as flat walls effectively pushes the drug in the second cavity, ensuring effective pressure transmission, allowing the central piston 3 to be fully compressed and move from the position cooperating with the closed section to the position cooperating with the open section.

[0078] According to some embodiments of this application, at least one of the first stop surface and the second stop surface is provided with an end face protrusion 302. The end face protrusion 302 provided between the first stop surface and the second stop surface can increase the stop sealing between the first stop surface and the second stop surface, and can maintain the end face seal after the volume of the second cavity is completely reduced, preventing the medium in the first cavity from flowing back.

[0079] In some embodiments of this application, the middle piston 3 and the bottom piston 2 are constructed as flexible members, and end face protrusions 302 are provided on at least one of the first stop surface and the second stop surface, which can help to provide a better sealing effect after they come into contact with each other.

[0080] In some other embodiments of this application, the first stop surface and the second stop surface may also be constructed as conical surfaces or curved surfaces with exactly the same shape and angle.

[0081] According to some embodiments of this application, the outer peripheral walls of the middle piston 3 and the bottom piston 2 are respectively formed with protruding waterproof lines 301. The waterproof lines 301 can be used to contact the wall of the injection chamber to maintain the sealing between the middle piston 3 and the injection chamber, so that when the middle piston 3 is engaged with the closed tube section, the first chamber does not leak, ensuring reliable sealing between the first chamber and the second chamber and preventing drug deterioration; ensuring the sealing between the bottom piston 2 and the injection chamber, so that the bottom piston 2 effectively seals the second chamber, and at the same time, reducing leakage during the pushing of the bottom piston 2, so that pressure is reliably transmitted to the middle piston 3, improving the reliability of the syringe assembly 100.

[0082] In some embodiments of this application, the waterproof line 301 may be configured as an annular first waterproof line 301 surrounding the outer periphery of the central piston 3, and the first waterproof line 301 may be configured as a plurality of such lines spaced apart in the axial direction; the waterproof line 301 may be configured as an annular second waterproof line 301 surrounding the outer periphery of the bottom piston 2, and the second waterproof line 301 may be configured as a plurality of such lines spaced apart in the axial direction.

[0083] In some embodiments of this application, the syringe assembly 100 further includes a piston rod 8, one end of which is connected to the bottom piston 2 and adapted to push the bottom piston 2 toward the central piston 3. The other end of the piston rod 8 extends out of the injection chamber, and the length of the piston rod 8 can be set slightly longer than the length of the injection chamber, so that when pushing the bottom piston 2, the piston rod 8 can completely push the bottom piston 2 to the front end of the injection chamber.

[0084] In some embodiments of this application, a bottom boss 204 is provided on the side of the bottom piston 2 away from the middle piston 3. The bottom boss 204 is used to improve the strength of the connecting piston push rod 8.

[0085] In some embodiments of this application, the other end of the straight needle tube 1 is provided with a bottom groove 104 on its outer periphery, which can be used to install the booster 7. The other end of the straight needle tube 1 is provided with a bottom guide slope 105, which is configured such that its diameter gradually decreases in the direction toward the other end. The claw 701 of the booster 7 is guided and fixed to the straight needle tube 1 by the bottom guide slope 105.

[0086] In some embodiments of this application, the material of the straight needle 1 may be borosilicate glass, polypropylene, polyethylene, polystyrene, polycarbonate, polymethyl methacrylate, cyclic olefin copolymer, cyclic olefin polymer and cyclic olefin block polymer. Preferably, the material of the straight needle is a cyclic olefin copolymer or a cyclic olefin polymer.

[0087] In some embodiments of this application, the booster 7 may be made of polypropylene, polyethylene, polystyrene, polycarbonate, polymethyl methacrylate, or acrylonitrile-butadiene-styrene copolymer. The inner edge of the booster 7 is provided with a claw 701, which is guided and fixed to the straight needle tube 1 by a guide slope 105 at the bottom of the straight needle tube 1. The claw 701 may be a single-ring claw 701, a two-ring claw 701, a three-ring claw 701, or a four-ring claw 701.

[0088] The bottom surface of the booster 7 has a groove 702, which should be in an interference fit or clearance fit with the bottom guide slope 105 of the straight needle tube 1, with a clearance not exceeding 1mm. The outer contour 704 of the booster 7 can be designed in various shapes according to ergonomics, such as circular, square, oval, etc. The interior of the booster 7 has a deformable cavity 703 to facilitate deformation under stress and prevent damage.

[0089] In some embodiments of this application, one end of the straight-through needle tube 1 forms a top end face 107. After vacuum freeze drying, the freeze dryer plates press down, pressing the end face boss 402 of the top piston 4 flush with the top end face 107 of the straight-through needle tube 1. One end of the straight-through needle tube 1 forms a top guide slope 108 whose diameter gradually decreases in the direction towards the other end. A corresponding guide slope 501 is also provided on the Luer lock cap. The top guide slope 108 of the straight-through needle tube 1 fixes the sealing recess 503 of the Luer lock cap to the straight-through needle tube 1, and the annular clamp 502 of the Luer lock cap is tightly fastened to the outer wall of the straight-through needle tube 1.

[0090] In some embodiments of this application, a waterproof line 201 is provided on the outer periphery of the bottom piston 2. The waterproof line 201 protrudes from the outer periphery of the bottom piston 2 to stop against the inner wall of the straight needle tube 1. An internal thread 202 is provided inside the bottom piston 2. A top protrusion 203 is formed on the top of the bottom piston 2 to prevent the middle piston 3 and the bottom piston 2 from sticking together during the manufacturing process.

[0091] A bottom boss 204 can be provided at the bottom of the bottom piston 2. The bottom boss 204 is used to improve the connection strength between the bottom piston 2 and the bottom piston 2 push rod.

[0092] In some embodiments of this application, a waterproof line 301 is provided on the outer periphery of the middle piston 3, and an end face protrusion 302 is provided on the bottom of the middle piston 3, which can prevent the middle piston 3 and the bottom piston 2 from sticking together during the manufacturing process.

[0093] In some embodiments of this application, a waterproof line 401 is provided on the outer periphery of the top piston 4.

[0094] In some embodiments of this application, the Luer lock cap may be made of polypropylene, polyethylene, polystyrene, polycarbonate, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer, and acrylic-butadiene-styrene copolymer, etc., and the Luer lock cap may be made of a transparent material. The guide slope 501 of the Luer lock cap, through the guide slope 108 at the top of the straight needle tube 1, fixes the sealing recess 503 of the Luer lock cap to the straight needle tube 1. The Luer lock cap is provided with an annular clamp 502, which is tightly fastened to the outer wall of the straight needle tube 1.

[0095] The diameter of the piston cavity 504 of the Luer lock cap should be larger than the diameter of the waterproof line 401 of the top piston 4. Preferably, when the top piston 4 is fully inserted into the piston cavity 504 of the Luer lock cap, the waterproof line 301 of the top piston 4 cannot cover the height of the top inner flow channel 109 of the straight needle tube 1. The mixed medicine can communicate with the outside through the path of the top inner flow channel 109 of the straight needle tube 1, the gap between the piston cavity 504 of the Luer lock cap and the waterproof line 301 of the top piston 4, the gap between the end face of the top piston 4 and the end face of the piston cavity 504 of the Luer lock cap, and the medicine outlet 506 of the Luer lock cap.

[0096] The gap between the end face of the top piston 4 and the end face of the inner cavity 504 of the Luer lock cover piston can be formed by the boss 402 on the end face of the top piston 4, or by the protrusion 508 in the inner cavity of the Luer lock cover.

[0097] In some embodiments of this application, the bottom piston 2 push rod 8 includes a flange 801, a rod body 802, an external thread 803, and a reinforcing rib 804. The internal thread 202 of the bottom piston 2 matches the external thread 803 of the bottom piston 2 push rod.

[0098] In some embodiments of this application, the bottom piston 2, the middle piston 3, and the top piston 4 may be made of polyisoprene, brominated butyl rubber, chlorinated butyl rubber, fluororubber, and thermoplastic elastomer, with a hardness range of 20 to 80 HA. Preferably, the bottom piston 2, the middle piston 3, and the top piston 4 are made of chlorinated butyl or brominated butyl rubber, with a hardness range of 35 to 55 HA.

[0099] The following is a brief description of a filling method for the syringe assembly 100 used in any of the above embodiments.

[0100] The filling method includes: filling the first cavity with liquid medicine through the first opening and installing the top piston 4; adjusting the top piston 4 to the first opening position and then performing vacuum freeze-drying on the inside of the straight needle tube 1.

[0101] At the position where vacuum freeze-drying is completed, the top piston 4 moves from the first opening position to the second opening position to close the first opening.

[0102] The filling method of this application has low process complexity for vacuum freeze-drying of liquid drugs, does not require additional locking cap structures, and the top piston 4 is compatible with other locking cap components 5, so there is no need to remove the top piston 4.

[0103] In some specific embodiments, during the filling of the syringe assembly of the present invention, the top end face 107 of the straight needle tube 1 faces upward, and the middle piston 3 is installed from above by mechanical stoppering. The pre-freeze-drying drug solution 12 is then filled from above. Subsequently, the top piston 4 is installed to the designated position from the top end face of the straight needle tube 1. At this time, the cavity of the straight needle tube 1 near the drug outlet can still communicate with the outside through the top internal flow channel 109, and the gas channel is open. The product is fed into the freeze dryer to begin vacuum freeze-drying. After vacuum freeze-drying is completed, the freeze dryer plates are pressed down, pressing the end face boss 402 of the top piston 4 flush with the top end face 107 of the straight needle tube 1. At this time, the cavity of the straight needle tube near the drug outlet cannot communicate with the outside through the outlet bypass, and the product is removed from the freeze dryer. The product is flipped over, with the bottom end face 106 of the straight needle tube 1 facing upward, and the solvent 9 is filled from above. The bottom piston 2 is then installed from above by vacuum stoppering or mechanical stoppering.

[0104] like Figure 10 As shown, when using the syringe assembly of the present invention, the Luer lock cap 6 is unscrewed and removed, and the injection needle is installed through the Luer lock thread 507 of the Luer lock cap 5. The bottom piston push rod 8 is installed, and the external thread 803 of the bottom piston push rod 8 engages with the internal thread 202 of the bottom piston 2. Pushing the bottom piston push rod 8 pushes all the solvent 9 in the cavity away from the drug outlet into the cavity near the drug outlet, where it is fully mixed with the lyophilized powder 10 to form a mixed drug solution 11. At the same time, the top piston 4 is fully inserted into the piston cavity 504 of the Luer lock cap 5. At this time, the mixed drug solution 11 communicates with the outside through the top internal flow channel 109 of the straight needle tube 1, the gap in the piston cavity 504, and the drug outlet 506. Pushing the bottom piston push rod 8 expels the gas in the cavity near the drug outlet, preparing for injection.

[0105] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0106] In the description of this invention, "first feature" and "second feature" may include one or more of the features.

[0107] In the description of this invention, "a plurality of" means two or more.

[0108] In the description of this invention, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0109] In the description of this invention, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature.

[0110] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0111] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A syringe assembly, characterized in that, include: A straight-through needle tube has an injection chamber formed inside. The injection chamber is opened through a first opening provided at one end of the straight-through needle tube. An outlet bypass is formed on the inner wall of the injection chamber adjacent to the first opening. The outlet bypass is used to allow gas in the injection chamber to be discharged through the outlet bypass during the freeze-drying process. A top piston is disposed at the first opening and is movable relative to the through needle. After the top piston moves, it moves to a first opening position and a second opening position. At the first opening position, at least a portion of the top piston intersects with the outlet bypass to keep the outlet bypass open. At the second opening position, at least a portion of the top piston is received within the injection chamber and closes the outlet bypass. At least a portion of the inner wall of the injection chamber is recessed to form the outlet bypass. The at least a portion of the inner wall of the injection chamber is configured as an abutment wall, and the abutment wall is located on the outer periphery of the outlet bypass. The top piston moves to the second opening position, at least a portion of the outer peripheral wall of the top piston abuts against the abutting wall to close the outlet bypass; the outlet bypass extends along the generatrix of the straight-through needle tube, and the outer periphery of the top piston is formed with a seal for contacting the abutting wall. In the first opening position, the seal and the outlet bypass are staggered to keep the outlet bypass open, and in the second opening position, the seal contacts the abutting wall and separates the outlet bypass from the injection chamber; The syringe assembly further includes: a locking cap assembly, which is disposed at the end of the straight needle tube and covers the outer periphery of the first opening, and the locking cap assembly is provided with a drug outlet; in After the top piston moves to the first opening position, a piston cavity communicating with the outlet bypass is formed between the top piston and the locking cap assembly, and the liquid medicine is communicated to the medicine outlet through the piston cavity; a protruding protrusion is formed on at least one of the top end face of the top piston and the bottom end face of the locking cap assembly. When the top piston moves to the first opening position, the protrusion abuts against the top end face of the top piston or the bottom end face of the locking cap assembly to maintain the piston cavity formed between the top end face of the top piston and the bottom end face of the locking cap assembly.

2. The syringe assembly according to claim 1, characterized in that, The locking cover assembly includes: A locking cover body, wherein the locking cover body has a receiving cavity and covers the end of the straight needle tube, and a first locking engagement member is formed on the upper part of the locking cover body; Luer cone, wherein the Luer cone is disposed on the locking cap body and forms a drug dispensing channel communicating with the receiving cavity; A Luer lock cap, wherein the Luer lock cap is provided with a second locking engagement member, and the Luer lock cap is placed over the Luer cone and locked to the first locking engagement member by the second locking engagement member.

3. The syringe assembly according to claim 2, characterized in that, Also includes: An injection device is provided, which can replace the Luer lock cap on the lock cover body, and the injection device is provided with a third locking engagement member that is detachably connected to the first locking engagement member.

4. The syringe assembly according to claim 1, characterized in that, The other end of the straight-through needle tube is provided with a second opening; The syringe assembly also includes: A middle piston and a bottom piston are provided. The middle piston is disposed in the injection chamber and located above the bottom piston, dividing the injection chamber into a first chamber and a second chamber. The bottom piston is close to the second opening. The first chamber is in communication with the first opening and is adapted to contain liquid drugs or powder media. The second chamber is adapted to contain liquid media. The first chamber and the second chamber are in communication.

5. The syringe assembly according to claim 4, characterized in that, The inner wall of the injection chamber has a recessed inner flow channel, the central piston is movable to the inner flow channel, and the outer peripheral wall of the central piston is spaced apart from the inner wall of the inner flow channel to form a gap that connects the first cavity and the second cavity.

6. A filling method for the syringe assembly according to any one of claims 4-5, characterized in that, include: Liquid drugs are filled into the first cavity through the first opening and the top piston is installed. After the top piston is adjusted to the first opening position, vacuum freeze-drying is performed on the inside of the straight needle tube. At the position where vacuum freeze-drying is completed, the top piston is moved from the first opening position to the second opening position to close the first opening.

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