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CN-121971745-A - Double-cavity prefilled syringe

CN121971745ACN 121971745 ACN121971745 ACN 121971745ACN-121971745-A

Abstract

The invention relates to a double-cavity pre-filling and sealing injector, wherein a needle cylinder is formed by sealing connection of a front cylinder body and a rear cylinder body, a front end sealing cap is detachably arranged on a luer connector at the front end of the front cylinder body, a push rod piston and a middle sealing piston are slidably arranged in a needle cylinder cavity in sequence, the middle sealing piston separates the needle cylinder cavity to form a liquid medicine storage cavity and a powder storage cavity, a bypass structure surface with a bypass groove is formed on the inner wall of the needle cylinder cavity, an axial blocking convex rib is arranged in the middle of the bypass structure surface, the middle sealing piston is blocked and kept positioned by the axial blocking convex rib in the liquid medicine mixing stage, the middle sealing piston can respond to the thrust of the push rod piston, passes over the blocking convex rib and enters a medicine injection stage, the front end sealing cap comprises a shell, one end of the assembly shell part of the shell is provided with a plug part, the other end of the assembly shell part is provided with an exhaust port opened and closed by a sealing end cap, and a filter element component for realizing liquid stopping and exhaust is arranged in the installation cavity of the assembly shell part. Has the advantages of safe, reliable and convenient drug mixing operation.

Inventors

  • ZHANG LIANGLIANG
  • Ni Nakai

Assignees

  • 浙江好博药业有限公司

Dates

Publication Date
20260505
Application Date
20260313

Claims (9)

  1. 1. A double-cavity prefilled syringe, which comprises a syringe, a push rod piston, a middle sealing piston and a front sealing cap, The syringe comprises a rear barrel and a front barrel, the front end of the front barrel is provided with a luer connector, a front end sealing cap is detachably arranged on the luer connector of the front barrel, the rear end of the front barrel is connected with the front end of the rear barrel in a sealing way, a cylindrical syringe cavity is formed, the syringe cavity is provided with a rear end opening corresponding to the rear end of the rear barrel, the front end of the syringe cavity is connected with a liquid outlet of the luer connector, The push rod is inserted into the needle cylinder along the rear end opening, the push rod piston and the middle sealing piston are sequentially and slidably arranged in the needle cylinder cavity, the push rod piston is arranged at a position closer to the rear end opening and is connected with the push rod, the middle sealing piston separates the needle cylinder cavity to form a liquid medicine storage cavity and a powder storage cavity, the liquid medicine storage cavity is positioned between the push rod piston and the middle sealing piston, the powder storage cavity is positioned between the middle sealing piston and the luer connector, The inner wall of the needle cylinder cavity is provided with a bypass structural surface at the joint end of the powder storage cavity and the liquid medicine storage cavity, a bypass groove is concavely arranged on the bypass structural surface, the axial length of the bypass groove is larger than that of the airtight sealing surface on the middle sealing piston, The working state of the middle sealing piston at least comprises an initial plugging stage, a liquid medicine mixing stage and a medicine injection stage, In the initial plugging stage, the middle sealing piston is configured to be positioned at the sealing position of the front port of the rear cylinder body, so that the mutual isolation of the liquid medicine storage cavity and the powder storage cavity is realized, In the liquid medicine mixing stage, the middle sealing piston moves to the bypass structural surface and forms a powder storage cavity which is communicated with the liquid medicine storage cavity through the bypass groove, The middle sealing piston responds to the axial thrust exerted by the push rod piston in contact with the middle sealing piston and moves in the powder storage cavity in the medicine injection stage, and is characterized in that an axial blocking convex rib is arranged in the middle of the bypass structural surface, the axial blocking convex rib is staggered with the bypass groove in the circumferential direction of the bypass structural surface, and the middle sealing piston is blocked and kept positioned by the axial blocking convex rib in the medicine liquid mixing stage; The front end sealing cap comprises a shell, the shell comprises an assembly shell part with an installation cavity, one end of the assembly shell part is provided with a plugging part connected with a luer connector, the other end of the assembly shell part is provided with an exhaust port, one end of the installation cavity is communicated with a needle cylinder cavity through the plugging part, the other end of the installation cavity is connected with the exhaust port, a filter element component for realizing liquid stopping and exhaust is arranged in the installation cavity, and a sealing end cover is arranged on the shell and is arranged to selectively close and open the exhaust port.
  2. 2. The dual-cavity pre-filled and sealed syringe according to claim 1, wherein the filter element member comprises a columnar filter element body and a rubber sleeve, the filter element body is plugged into a sleeve hole of the rubber sleeve, the filter element body comprises a buffer layer made of hydrophilic material and a breathable isolation layer made of hydrophobic material, the isolation layer and the buffer layer are arranged in an axial stacking mode, the isolation layer is configured at one end close to the exhaust port, the buffer layer faces one end of the syringe cavity, the sleeve hole of the rubber sleeve is an axial variable-cross-section hole, the sleeve hole is formed with a maximum inner diameter part in the axial middle section, the inner diameter value of the maximum inner diameter part is larger than the inner diameter value of opening areas at two ends of the sleeve hole, the isolation layer and the buffer layer of the filter element body are arranged in the maximum inner diameter part, the rubber sleeve is in sealing fit in the mounting cavity, and two ends of the filter element body are in interference fit with the opening areas at two ends of the sleeve hole respectively.
  3. 3. The dual chamber prefilled syringe of claim 2, wherein said mounting housing portion is barrel-shaped, said mounting housing portion defines an axial open end and a bottom opposite said open end, said mating portion is integrally formed on said bottom, said vent port is disposed at said axial open end of said mounting housing portion, said mounting chamber has a stepped axial cross section, said mounting chamber includes an inner chamber section and an outer chamber section coaxially disposed, wherein said outer chamber section is disposed adjacent said vent port, an inner diameter of said inner chamber section is greater than an inner diameter of said outer chamber section, an axially positioned step surface is formed between adjacent ones of said inner chamber section and said outer chamber section, said rubber sleeve includes a large diameter contour portion, a small diameter contour portion and an axially positioned step surface, said large diameter contour portion outer contour is configured to mate with an inner wall of said inner chamber section of said mounting chamber, said axially positioned step surface is formed between said large diameter contour portion and said small diameter contour portion, said rubber sleeve is inserted into said rubber sleeve along said axial end, and said rubber sleeve is mounted against said step surface, and said rubber sleeve is mounted against said axial support surface.
  4. 4. The syringe of claim 1, wherein the luer fitting comprises a central inner cone and an internally threaded sleeve disposed around the central inner cone, the connector comprises a ferrule and a plug core tube, the ferrule is sleeved outside the central inner cone and screwed with the internally threaded sleeve, and the plug core tube is inserted into the internal flow passage of the central inner cone.
  5. 5. The syringe of claim 1, wherein the outer circumference of the front part of the rear barrel is provided with an external thread and a sealing external conical surface, the sealing external conical surface is positioned between the front end of the external thread and the front end face of the rear barrel, the front barrel is integrally provided with a plug-in sleeve part at the rear end thereof, the plug-in sleeve part is provided with a plug-in sleeve hole, the inner diameter of the plug-in sleeve hole is larger than the inner diameter of the syringe cavity, a shaft shoulder is defined at the joint of the plug-in sleeve part and the front barrel, the plug-in sleeve hole of the plug-in sleeve part is internally provided with an internal thread and a sealing internal conical surface which are respectively correspondingly matched with the external thread on the rear barrel and the sealing external conical surface matched with the external thread, and the bypass structural surface is formed in the front barrel, and one axial end of the bypass groove penetrates through the shaft shoulder.
  6. 6. The syringe of claim 1, wherein the rear end of the rear barrel is provided with a finger grip member, the finger grip member comprises a cylindrical part and a flange part, the cylindrical part is sleeved on the rear end of the rear barrel, the flange part extends along the radial outward direction of the base end of the cylindrical part, the push rod is axially provided with a ratchet surface, and the cylindrical part is provided with a push rod locking member, and the push rod locking member is configured to allow the push rod to move towards the front end of the syringe to prevent the push rod from withdrawing by unidirectional engagement of the locking head and the ratchet surface.
  7. 7. The dual chamber pre-filled syringe of claim 6 wherein said pushrod locking member is received in an interior bore of said barrel.
  8. 8. The syringe of claim 7, wherein the push rod locking member has a fixed base fixed on the inner wall of the cylindrical portion, the inner end of the fixed base is integrally formed with an elastically deformable elastic arm, and the free end of the elastic arm is formed with a locking head engaged with the ratchet surface.
  9. 9. The syringe of claim 8, wherein the barrel is further provided with a positioning guide seat, the positioning guide seat and the push rod locking member are circumferentially distributed along the inner hole of the barrel, the positioning guide seat is fixed on the inner hole wall of the barrel and is provided with an axially-through guide groove, the push rod comprises a proximal backing plate, a push rod main body and a distal piston connector, the distal piston connector and the proximal backing plate are respectively formed at two axial ends of the push rod main body, the push rod piston is connected to the distal piston connector, the push rod main body comprises a main body and a plurality of wings, the wings radially extend from the periphery of the main body and are radially arranged around the axis of the main body, the wings comprise locking wings and guiding wings, the outer diameter side of the locking wings is provided with ratchet teeth surfaces for being matched with corresponding push rod locking members, the guiding wings are received in the guide groove of the positioning guide seat, the guiding wings are matched with the guide groove and are configured to guide the push rod to slide axially while limiting the rotation of the push rod around the axis thereof.

Description

Double-cavity prefilled syringe Technical Field The invention relates to a medical apparatus, in particular to a double-cavity prefilled syringe. Background Conventional syringes and prefilled syringes have some limitations in use. Specifically, the traditional injector needs to dispense medicines in advance aiming at powder injection preparations, and is matched with a plurality of accessories such as a penicillin bottle, a disposable sterile injector and the like for use, so that the use process is complex and complicated, and pollution is easy to cause in the secondary suction and puncture processes of the sterile injector. To solve the above problems, a modified double-chamber prefilled syringe has been developed and used, in which powder and liquid components are kept separate during storage, and an existing modified design is disclosed in CN 101873872A, CN1750852A, CN113855933A, CN119345532 a and the like. The main functional structure is that the liquid component and the powder are arranged in the same cartridge or injection barrel, wherein one or more sealing elements are arranged for separating the two components. In use, the sealing element is pushed to a bypass position on the syringe, the two medicament storage chambers are in communication, and the liquid components enter the powder storage chambers for mixing. According to the prior art, the double-cavity pre-filled and sealed injector has an integrated design scheme, but has the problem of inconvenient molding, the process of dispensing is time-consuming and labor-consuming, a certain pollution risk exists, and medicine waste or inaccurate dosage can be caused in the operation process. The double-cavity pre-filling and sealing injector in a combined mode is more convenient to mold, is easy to separate and load liquid medicine and powder, cannot pollute each other in the liquid filling and powder adding processes, and has the advantages of lower cost and the like as disclosed in CN 113855933A. However, in the existing split type double-cavity pre-filling and sealing injector scheme, during the drug mixing operation, in order to ensure that liquid is smoothly pushed into a powder storage cavity, a sealing cap at the front end of the powder storage cavity is removed, so that sterility during drug mixing cannot be ensured. Although the integral injector (such as the scheme disclosed in CN 1750852A) is provided with a front end sealing plunger for plugging, the additional sealing plunger is inevitably introduced into the cavity of the syringe, so that the structure is complex, inconvenience is brought to assembly and processing, and the operation of liquid medicine pushing injection is more laborious and inconvenient. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a split-type double-cavity pre-filling and sealing syringe which has the advantages of safe, reliable and convenient medicine mixing operation. In order to achieve the above purpose, the present invention provides the following technical solutions: a double-cavity prefilled syringe, which comprises a syringe, a push rod piston, a middle sealing piston and a front sealing cap, The syringe comprises a rear barrel and a front barrel, the front end of the front barrel is provided with a luer connector, a front end sealing cap is detachably arranged on the luer connector of the front barrel, the rear end of the front barrel is connected with the front end of the rear barrel in a sealing way, a cylindrical syringe cavity is formed, the syringe cavity is provided with a rear end opening corresponding to the rear end of the rear barrel, the front end of the syringe cavity is connected with a liquid outlet of the luer connector, The push rod is inserted into the needle cylinder along the rear end opening, the push rod piston and the middle sealing piston are sequentially and slidably arranged in the needle cylinder cavity, the push rod piston is arranged at a position closer to the rear end opening and is connected with the push rod, the middle sealing piston separates the needle cylinder cavity to form a liquid medicine storage cavity and a powder storage cavity, the liquid medicine storage cavity is positioned between the push rod piston and the middle sealing piston, the powder storage cavity is positioned between the middle sealing piston and the luer connector, The inner wall of the needle cylinder cavity is provided with a bypass structural surface at the joint end of the powder storage cavity and the liquid medicine storage cavity, a bypass groove is concavely arranged on the bypass structural surface, the axial length of the bypass groove is larger than that of the airtight sealing surface on the middle sealing piston, The working state of the middle sealing piston at least comprises an initial plugging stage, a liquid medicine mixing stage and a medicine injection stage, In the initial plugging stage, the middle sealing piston is configu