Pre-encapsulation protective cap assembly with sublimation channel, drug delivery device and drug delivery method

Abstract

The invention discloses a pre-encapsulation protective cap assembly with a sublimation channel and a drug delivery device and method, the pre-encapsulation protective cap assembly comprises a shell and a rubber plug located in the shell, the hard shell is provided with a fastening structure, an anti-skid structure, an exhaust channel, a rubber plug inner cavity, a limiting buckle and a limiting boss, and the rubber plug is provided with a sealing lantern ring, a first limiting clamping groove and a second limiting clamping groove. The elastic body rubber plug sealing lantern ring keeps elastic contact and friction connection with the medicine outlet to form sealing, the hard shell protectively seals the elastic body rubber plug in an elastic contact, friction connection and clamping groove limiting mode, and meanwhile a fastening structure of the hard shell is connected with a needle head connecting part of the medicine outlet to guarantee sealing. When administration is needed, the shell is separated from the connecting part of the needle head, and the rubber plug can be separated from the medicine outlet of the needle tube at the same time.

Description

Technical Field

[0001] The invention belongs to medical equipment, and in particular relates to a pre-filled protective cap assembly with a sublimation channel, a drug delivery device and a method. Background Art

[0002] Conventional syringes generally include a needle tube assembly having an open proximal end and an opposite distal end, a cylindrical barrel wall extending between the proximal end and the distal end, and the interior thereof is called a drug storage chamber. The drug outlet extends from the distal end of the needle tube, and the interior thereof is a narrow passage connected to the drug storage chamber. A plunger can be inserted into the proximal end of the needle tube opening to seal the drug in the drug storage chamber. The sliding movement of the plunger in the distal direction causes the drug in the drug storage chamber to flow out of the drug outlet. Conversely, the sliding movement of the plunger in the proximal direction will cause the drug to flow into the drug outlet and enter the drug storage chamber of the needle tube.

[0003] This type of syringe is generally matched with a needle assembly, which includes an injection needle and a base. The injection needle has a proximal end, a sharp distal end and a cylindrical cavity penetrating inside. The base has a proximal end connected to the injection needle and a distal end connected to the mounting position on the needle tube. The distal end of the base is used to connect the cylindrical cavity penetrating inside the injection needle with the drug outlet of the needle tube.

[0004] The connecting device connecting the syringe and the needle assembly is generally a Luer ring coaxially arranged around the drug outlet. The Luer ring is provided with a structure for fastening the connection, and a corresponding connecting mechanism is provided on the base of the needle assembly. Depending on the material of the needle tube, the Luer ring has different structural forms. A needle tube made of plastic can be made into a Luer ring with an integrated structure. In order to avoid the manufacturing process being too complicated for a glass needle tube, the Luer ring is generally a split structure, which is connected to the drug outlet of the needle tube by means of a snap connection or the like.

[0005] The drug pre-filled into the syringe must be sealed to prevent drug contamination or loss. The sealing device includes a plunger and a protective cap assembly installed at the drug outlet of the syringe. Furthermore, for the convenience of storage, some drugs use a vacuum freeze-drying process to sublimate the drug solvent from a solid state to a gas state without destroying the original chemical structure and morphology. After re-dissolving, the biologically active material can still restore the conformation and biological function before freeze-drying. In order to meet the above needs, a double-chamber prefilled syringe has appeared in recent years. This structure integrates drug storage, mixing and administration. The interior of the syringe is divided into two independent chambers by two plungers. The chamber near the drug outlet stores the freeze-dried powder, and the chamber away from the drug outlet stores the diluent. When in use, the diluent is pushed into the chamber near the drug outlet to mix with the freeze-dried powder, and then injected. However, for syringes with a Luer ring at the drug outlet, after the syringe is filled with medicine and enters the freeze dryer, the sublimated gas needs a sufficient sublimation channel to be discharged from the drug storage chamber. The existing protective cap cannot be assembled to the needle tube drug outlet before entering the freeze dryer, and adding a protective cap assembly station in the freeze dryer is too complicated. Therefore, it is necessary to transfer the medicine to the outside for protective cap assembly after freeze drying. However, the medicine will absorb moisture during the transfer process, causing the medicine to clump or even fail. Summary of the invention

[0006] Purpose of the invention: In order to solve the contradiction between the freeze-drying process and sealed storage of drugs in a double-chamber prefilled syringe with a Luer ring at the drug outlet, the present invention provides a prefilled cap assembly with a sublimation channel, and also provides an application method of the prefilled cap assembly.

[0007] Technical solution: A pre-filled protective cap assembly with a sublimation channel, the protective cap assembly is located at the drug outlet end of the needle tube, and the drug outlet end is provided with a drug outlet. The protective cap assembly includes a shell and a rubber plug. The rubber plug is located at different positions in the shell to achieve sealing or exhaust of the drug storage cavity during the freeze-drying operation, forming a sublimation channel for the solution freeze-drying process;

[0008] The shell is provided with an exhaust channel, a rubber plug inner cavity and a limit buckle, and the rubber plug is provided with a first limit slot and a second limit slot;

[0009] The limit buckle cooperates with the first limit slot, and the medicine storage cavity formed by the plunger in the syringe can be vented through the exhaust channel; when the limit buckle cooperates with the second limit slot, the medicine outlet is blocked and the medicine storage cavity is closed.

[0010] Furthermore, the needle tube is provided with a needle connection part at the medicine outlet end, including a coaxial arrangement, and the two are used for fastening the housing;

[0011] The shell is also provided with a fastening structure and a limiting boss. The fastening structure is used to fit with the needle connecting part, and the limiting boss is used to fit with the end of the rubber plug to achieve sealing.

[0012] Furthermore, the fastening structure in the housing is located in a groove formed by the liquid outlet and the needle connecting portion, and the outer side of the needle connecting portion can be connected to the needle;

[0013] A convex ring is arranged between the fastening structure and the exhaust channel, and is used to abut against the needle connecting part for sealing.

[0014] The fastening structure is provided with a threaded structure and matches the internal thread of the Luer lock syringe;

[0015] Furthermore, a sealing ring is provided at the position where the plunger contacts the inner wall of the needle tube.

[0016] Furthermore, the needle tube includes block polymers including polypropylene, polyethylene, polystyrene, polycarbonate, polymethyl methacrylate, cycloolefin copolymer, cycloolefin polymer and cycloolefin.

[0017] The rubber plug is made of elastic material, including polyisoprene, brominated butyl rubber, chlorinated butyl rubber, fluororubber and thermoplastic elastomer, and the hardness ranges from 20 to 80HA.

[0018] The plunger is made of polyisoprene, brominated butyl rubber, chlorinated butyl rubber, fluororubber and thermoplastic elastomer, and has a hardness range of 20 to 80 HA.

[0019] Furthermore, the sealing collar in the rubber plug of the assembly forms a seal by maintaining elastic contact and friction connection with the drug outlet; the shell protectively closes the rubber plug by elastic contact, friction connection and card slot limiting, and the drug outlet and the needle connecting part are separately arranged, and the fastening structure in the shell is connected with the drug outlet and the needle connecting part to ensure sealing;

[0020] The outer shell and the needle connecting part in the assembly are separated, and the rubber plug and the medicine outlet on the needle tube can be separated at the same time.

[0021] A dual-chamber drug delivery device capable of storing liquid or solid at the same time, the drug delivery device comprises the above-mentioned pre-filled protective cap assembly with a sublimation channel, the drug storage chamber in the needle tube is separated by a separation piston in the needle tube for storing different forms of drugs, and the separation piston is provided with a bypass flow channel along the inner wall of the needle tube;

[0022] The drug storage chamber near the drug outlet is used for filling liquid and storing or freeze-drying the drug.

[0023] Furthermore, the bypass flow channel is provided by grooving on the inner wall of the needle tube, including a long strip or a racetrack shape, whose length is greater than the thickness or length of the separation piston. The separation piston moves under pressure in the rear end chamber. When in the bypass flow channel, the solvent in the rear chamber can enter the front chamber through the bypass flow channel for mixing, thereby completing the administration or injection of the drug.

[0024] In combination with the above-mentioned prefilled protective cap assembly, the present invention also provides an application method thereof, specifically an application method of the prefilled protective cap assembly,

[0025] Before the medicine is ready to be poured into the medicine storage cavity, the housing is connected to the needle connection device of the needle tube through a fastening structure, the plunger is set to the designated position of the medicine storage cavity by the filling device, and then the liquid medicine is filled from the medicine outlet;

[0026] After the liquid medicine is filled, the elastic plug is pressed down, and the first limit card slot cooperates with the limit card buckle of the shell, and then the freeze-drying process is carried out, during which the sublimated gas of the liquid medicine is discharged through the exhaust channel of the shell;

[0027] After the liquid medicine is converted into freeze-dried powder, the elastomeric plug is pressed down, and the second limiting groove cooperates with the limiting buckle of the shell. At this time, the sealing ring and the drug outlet are sealed through elastic contact and friction connection, and the elastomeric plug fits tightly with the plug inner cavity and limiting boss of the shell to ensure reliable connection.

[0028] Furthermore, for a dual-chamber drug delivery device that can store liquid or solid at the same time, the method includes first fixing the separation piston, then assembling the outer shell, filling the solvent to be freeze-dried from the drug outlet, and then sealing by pressing the rubber plug to perform the freeze-drying sublimation operation of the solvent; and then filling the liquid solvent through the end where the plunger is located, and after the filling is completed, the plunger is used to push the drug delivery operation.

[0029] Beneficial effects: The prefilled cap assembly provided by the present invention firstly has a sublimation channel for the medicine during the freeze-drying process, and can eliminate the need to replace the cap assembly during the entire prefilling and subsequent use process, and when removing the cap assembly, it can be removed together with the sealing structure, which is convenient and more importantly, considering the shortcomings of the existing caps of double-chamber prefilled syringes with Luer rings at the drug outlet, the prefilled cap assembly provided by the present invention can be assembled before entering the freeze dryer, and after freeze-drying is completed, it only needs to be pressed into place in the freeze dryer to complete the sealing, and there is no need to transfer it outside the freeze dryer for additional cap assembly, which greatly reduces the risk of moisture absorption or agglomeration of the medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the needle tube;

[0031] Figure 2 It is a schematic diagram of the outer shell structure of the protective cap assembly of the present invention;

[0032] Figure 3 It is a schematic diagram of the rubber plug structure in the protective cap assembly of the present invention;

[0033] Figure 4 is a schematic diagram of the plunger structure of the present invention;

[0034] Figure 5 It is a schematic diagram of the relative position relationship of the overall structure of the present invention before installation;

[0035] Figure 6 This is a schematic diagram of the structure of the present invention after filling and preparation for freeze-drying;

[0036] Figure 7 It is a schematic diagram of the structure of the present invention completing freeze-drying and preparing for transfer. DETAILED DESCRIPTION

[0037] To illustrate the technical solution disclosed in the present invention in detail, a further introduction is given below in conjunction with the accompanying drawings.

[0038] In order to facilitate the preservation of certain drugs, a vacuum freeze-drying process is used to sublimate the drug solvent from a solid state to a gaseous state without destroying the original chemical structure and morphology of the solute. After being redissolved, biologically active materials can still restore their pre-freeze-drying conformation and biological function. After the syringe needle completes the drug filling and enters the freeze dryer, the solvent needs sufficient sublimation channels to be discharged from the drug storage cavity, which means that the existing protective cap cannot be assembled to the needle outlet before entering the freeze dryer, and adding a protective cap assembly station in the freeze dryer is too complicated. Therefore, it is necessary to transfer the protective cap to the outside for protective cap assembly after the freeze drying is completed. However, during the transfer process, the drug will absorb moisture, causing the drug to agglomerate or even fail. In response to this technical problem, the present invention provides a pre-filled protective cap assembly with a sublimation channel, which can enable the protective cap assembly to be completed in the freeze dryer while minimizing the impact on the freeze drying process.

[0039] The medicine pre-filled into the needle tube must be sealed to prevent drug contamination or loss. The sealing device includes a plunger and a protective cap assembly installed at the drug outlet of the needle tube to prevent leakage and avoid drug contamination. The protective cap assembly generally includes a hard shell and an elastomeric plug. The hard shell has a fastening structure, an anti-slip structure, a plug inner cavity, a limit buckle and a limit boss. The elastomeric plug has a sealing ring and a limit slot. The hard shell is fastened with the limit slot of the elastomeric plug through the limit boss and the limit buckle. The protective cap assembly is locked to the proximal end of the needle tube through the hard shell fastening structure, and the elastomeric plug sealing ring maintains elastic contact and friction connection with the drug outlet of the needle tube at this time. Before using the syringe, the protective cap is removed from the drug outlet of the needle tube, and then the base of the needle assembly can be fastened with the Luer ring. For example, the base of the needle assembly can be engaged with the inner thread of the Luer ring so that the cylindrical cavity passing through the injection needle of the needle assembly is connected to the drug outlet of the needle tube.

[0040] Combination Figure 1-Figure 7 The structure shown, the syringe needle tube associated therewith has an open proximal end and an opposite distal end, a cylindrical barrel wall extends between the proximal end and the distal end, and the interior thereof is called a drug storage chamber. The drug outlet extends from the distal end of the needle tube, and the interior thereof is a narrow passage connected to the drug storage chamber. The drug outlet is provided with a needle mounting device, and the needle mounting device is fastened to the connecting structure on the needle assembly base. The needle mounting device can be an annular structure integrally formed with the syringe barrel, or a split annular structure firmly mounted on the drug outlet. Preferably, such an annular structure can be a Luer lock.

[0041] The protective cap assembly provided by the present invention includes a hard shell and an elastomeric plug, the shell having a fastening structure, an anti-slip structure, an exhaust channel, an inner cavity of the plug, a limit buckle and a limit boss, and the elastomeric plug having a sealing collar, a first limit slot and a second limit slot. The sealing collar of the elastomeric plug forms a seal by maintaining elastic contact and friction connection with the drug outlet, while the hard shell protectively seals the elastomeric plug by elastic contact, friction connection and slot limitation, and at the same time, the fastening structure of the hard shell is connected to the needle connection part of the drug outlet to ensure sealing. Therefore, by separating the hard shell from the needle connection part, the elastomeric plug can be separated from the drug outlet of the needle tube at the same time.

[0042] Before entering the freeze dryer, the plunger enters the drug storage chamber through the proximal end of the needle tube opening, the fastening structure of the hard shell is fastened to the needle mounting device of the drug outlet, and at the same time, the first limit slot of the elastomeric plug is connected to the limit buckle of the hard shell. After entering the freeze dryer to complete freeze drying, the elastomeric plug is pressed down by the pressing mechanism until the second limit slot is connected to the limit buckle of the hard shell. At this time, the drug outlet of the needle tube and the sealing ring of the elastomeric plug form a seal through elastic contact and friction connection.

[0043] Specifically, if Figure 1 As shown, the needle tube 1 includes a proximal end 101, a drug storage cavity 102, a needle connection portion 103 and a drug outlet 104. The needle tube 1 is formed of a single material, such as glass or plastic, and can be set to be transparent. Preferably, the material of the needle tube includes but is not limited to polypropylene, polyethylene, polystyrene, polycarbonate, polymethyl methacrylate, cycloolefin copolymer, cycloolefin polymer and cycloolefin block polymer.

[0044] like Figure 2 As shown, the outer shell 2 in the protective cap assembly includes a fastening structure 201, an anti-slip structure 202, an exhaust channel 203, a limit buckle 204, a rubber plug cavity 205 and a limit boss 206. The material of the outer shell includes but is not limited to polypropylene, polyethylene, polystyrene, polycarbonate, polymethyl methacrylate, etc., and is hard.

[0045] More specifically, the fastening structure 201 can be set as a threaded column, which can be embedded in the groove between the needle connection part 103 and the drug outlet 104. Its depth is flush with the height of the needle connection part 103. A convex ring is set at the flush position to achieve limiting, but the convex ring does not affect the external installation of the needle and the needle connection part 103. An exhaust channel 203 is set on the upper part of the convex ring, and an anti-slip structure 202 can be set on the outer side to remove the shell 2 as a whole or rotate it out. The interior of the shell 2 is used to accommodate the rubber plug 3. A limiting boss 206 is also set on the shell 2 for preliminary positioning (pre-filling preliminary sealing). Combined with the internal setting of the limiting buckle 204, the position control of the rubber plug 3 is achieved, including the exhaust volume control of the exhaust channel. The control accuracy includes thread and spiral methods to improve the control accuracy.

[0046] like Figure 3 As shown, the rubber plug 3 in the protective cap assembly includes a sealing ring 301, a first limit slot 302 and a second limit slot 303. The material of the elastomeric rubber plug includes but is not limited to polyisoprene, brominated butyl rubber, chlorobutyl rubber, fluororubber and thermoplastic elastomer, and the hardness ranges from 20 to 80HA.

[0047] like Figure 4 As shown, the plunger is a cylindrical structure as a whole, and a sealing ring 401 is provided on the side wall. Preferably, the plunger is made of materials including but not limited to polyisoprene, brominated butyl rubber, chlorobutyl rubber, fluororubber and thermoplastic elastomer, and the hardness ranges from 20 to 80 HA.

[0048] like Figure 5 and Figure 6 As shown, before the medicine is ready to be filled into the medicine storage cavity 102, the shell 2 is connected to the needle connection part 103 of the needle tube 1 through the fastening structure 201, and the plunger 4 is set to the specified position of the medicine storage cavity 102 by the filling device, and then the liquid medicine 5 is filled through the medicine outlet 104. After the liquid medicine 5 is filled, the elastic plug 3 is pressed down, and the first limiting card groove 302 cooperates with the limiting buckle 204 of the hard shell 2, and then the freeze-drying process is carried out, and the sublimated gas is discharged through the exhaust channel 203 of the hard shell 2.

[0049] like Figure 7 As shown, after the freeze-drying process is completed, the liquid medicine 5 becomes a freeze-dried powder 6. The rubber plug 3 is pressed down, and the second limiting groove 303 cooperates with the limiting buckle 204 of the hard shell 2. At this time, the sealing ring 301 and the drug outlet 104 are sealed by elastic contact and friction connection. The elastic rubber plug 3 and the rubber plug inner cavity 205 and the limiting boss 206 of the shell 2 are tightly fitted to ensure reliable connection. Then the whole is transferred out of the freeze dryer for subsequent processes.

[0050] In the existing freeze-drying process, the same components are generally used for freeze-drying and storage after freeze-drying, otherwise the drug will absorb moisture. The present invention is quite different from the existing drug storage container, freeze-drying steps and drug administration methods. A needle tube (which can be directly used for drug administration and storage) and the protective cap assembly of the present invention are used to pre-fill the syringe of the drug, including the function of a double-chamber pre-filled syringe. At the same time, the pre-filling method is to fix the outer shell 2, combine the rubber plug to form a drug storage cavity, and then pre-fill from the drug outlet, combining the initial seal and the secondary seal to avoid contamination.

[0051] Further combined with the above-mentioned application method, it can be known that before the freeze-drying of the medicine, the shell of the present invention is fastened to the internal thread of the Luer lock syringe through the lower end threaded structure, and the elastomeric plug is fixed at the first limit slot through the upper end buckle of the shell, which can achieve preliminary sealing and positioning, and the exhaust volume can be controlled well. In combination with this structure, it can be convenient for batch application, and the corresponding position is set according to the exhaust characteristics of different medicines in the sublimation process, so as to avoid the existing unlimited and fixed position pressing, which will cause the exhaust volume to be too large or too small (too large will cause the solvent to overflow easily during the operation, too small will hinder the exhaust during the freeze-drying operation, and it is also possible that the exhaust cannot be performed due to inaccurate operation). After the freeze-drying operation is completed, the present invention makes the elastomeric plug contact the hard shell limit boss first for preliminary limit by pressing down the plate layer, and further presses down, so that the elastomeric plug is deformed so that the second limit slot of the elastomeric plug cooperates with the hard shell buckle, thereby pressing the elastomeric plug tightly, and sealing the drug outlet of the Luer lock prefilled syringe.

Claims

1. A pre-filled protective cap assembly with a sublimation channel, wherein the protective cap assembly is located at the drug outlet end of a needle tube (1), and the drug outlet end is provided with a drug outlet (104), characterized in that: The protective cap assembly comprises a shell (2) and a rubber plug (3), and the rubber plug (3) is placed at different positions in the shell (2) to achieve sealing or exhaust of the drug storage cavity (102) during the freeze-drying operation, thereby forming a sublimation channel required in the freeze-drying process of the solution; The shell (2) is provided with an exhaust passage (203), a rubber plug inner cavity (205) and a limit buckle (204), and the rubber plug (3) is provided with a first limit slot (302) and a second limit slot (303); When the position-limiting buckle (204) cooperates with the first position-limiting slot (302), the medicine storage chamber (102) formed by the plunger (4) in the needle tube (1) can be vented through the exhaust channel (203); when the position-limiting buckle (204) cooperates with the second position-limiting slot (303), the medicine outlet (104) is blocked and the medicine storage chamber (102) is closed.

2. The prefilled protective cap assembly according to claim 1, characterized in that: The needle tube (1) is provided with a needle connection part (103) at the drug outlet (104) end, and the two are coaxially arranged, and the housing (2) is fastened therebetween; The housing (2) is further provided with a fastening structure (201) and a limiting boss (206), wherein the fastening structure (201) is used to fit with the needle connecting portion (103), and the limiting boss (206) is used to fit with the end of the rubber plug (3) to achieve sealing.

3. The prefilled protective cap assembly according to claim 2, characterized in that: The fastening structure (201) in the housing (2) is located in a groove formed by the liquid outlet (104) and the needle connecting portion (103), and the outer side of the needle connecting portion (103) is capable of connecting a needle; A convex ring is provided between the fastening structure (201) and the exhaust channel (203) and is used to abut against the needle connection part (103) for sealing.

4. The prefilled protective cap assembly according to claim 2, characterized in that: The fastening structure (201) is provided with a threaded structure and matches the internal thread of the Luer lock syringe.

5. The prefilled protective cap assembly according to claim 1, characterized in that: The plunger (4) is provided with a sealing ring (401) at a position where it contacts the inner wall of the needle tube (1).

6. The prefilled protective cap assembly according to claim 1, characterized in that: The needle tube (1) comprises a block polymer including polypropylene, polyethylene, polystyrene, polycarbonate, polymethyl methacrylate, cycloolefin copolymer, cycloolefin polymer and cycloolefin; The rubber plug (3) is made of elastic material, including polyisoprene, brominated butyl rubber, chlorobutyl rubber, fluororubber and thermoplastic elastomer, and has a hardness range of 20 to 80 HA; The material of the plunger (4) includes polyisoprene, brominated butyl rubber, chlorinated butyl rubber, fluororubber and thermoplastic elastomer, and the hardness ranges from 20 to 80 HA.

7. The prefilled protective cap assembly according to claim 1, characterized in that: The prefilled protective cap assembly according to claim 1 is characterized in that the sealing ring (301) in the rubber plug (3) of the assembly forms a seal by maintaining elastic contact and friction connection with the drug outlet (104); the shell (2) protectively closes the rubber plug (3) by means of elastic contact, friction connection and slot limiting, and the drug outlet (104) and the needle connecting part (103) are separately arranged, and the fastening structure (201) in the shell (2) is connected to the drug outlet (104) and the needle connecting part (103) to ensure sealing; In the assembly, the housing (2) and the needle connection portion (103) are separated, which can simultaneously separate the rubber plug (3) from the drug outlet (104) on the needle tube (1).

8. A dual-chamber drug delivery device capable of storing liquid or solid at the same time, characterized in that: The drug delivery device comprises a pre-filled protective cap assembly with a sublimation channel as claimed in any one of claims 1 to 7, wherein the drug storage chamber (102) in the needle tube (1) is separated by a separation piston for storing drugs in different forms, and the separation piston is provided with a bypass flow channel along the inner wall of the needle tube; The drug storage chamber near the drug outlet (104) includes a chamber for filling liquid for storing or freeze-drying drugs.

9. A method for applying a pre-filled protective cap assembly, characterized in that: Using the pre-filled protective cap assembly as described in any one of claims 1 to 7; Before the medicine is ready to be poured into the medicine storage chamber (102), the housing (2) is connected to the needle connection device (103) of the needle tube (1) via the fastening structure (201), the plunger (4) is set to a designated position in the medicine storage chamber (102) by the filling device, and then the liquid medicine is filled from the medicine outlet (104); After the liquid medicine is filled, the elastic plug (3) is pressed downward, and the first limit groove (302) cooperates with the limit buckle (204) of the shell (2), and then the freeze-drying process is carried out, during which the sublimated gas of the liquid medicine is discharged through the exhaust channel (203) of the shell (2); After the liquid medicine is converted into a lyophilized powder, the elastomeric plug (3) is pressed downward, and the second limiting groove (303) cooperates with the limiting buckle (204) of the shell (2). At this time, the sealing ring (301) and the drug outlet (104) are sealed by elastic contact and friction connection, and the elastomeric plug (3) and the plug inner cavity (205) and the limiting boss (206) of the shell (2) are tightly fitted to ensure reliable connection.

10. The method for applying the prefilled protective cap assembly according to claim 9, characterized in that: For a dual-chamber drug delivery device capable of storing liquid or solid at the same time, the method comprises first fixing the separation piston, then assembling the housing (2), filling the to-be-lyophilized solvent from the drug outlet (104), and then sealing by pressing the rubber plug (3) to perform a lyophilization and sublimation operation of the solvent; and then filling the liquid solvent through the end where the plunger (4) is located, and after the filling is completed, the plunger (4) is used to push the drug delivery operation.

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