CN114712618A - Double-chamber syringe and charging method - Google Patents

Abstract

The invention belongs to the field of medicines and medical instruments, and relates to a double-chamber syringe and a charging method. Specifically, include injection head (21), syringe (10), plug (16) and push rod (32), wherein: the injection cylinder (10) comprises a front chamber cylinder (11) and a rear chamber cylinder (13), wherein the front chamber cylinder (11) is detachable. The invention reduces the preparation process flow of the solid powder after the freeze-drying of the medicine, realizes that the solid medicine and the injection are pre-filled in the same injector, can realize the one-time completion of the medicine dispensing and the injection, has simple and convenient operation, avoids the pollution of the medicine packaging and the medicine dispensing process, and obviously reduces the preparation and use cost.

Description

Double-chamber syringe and charging method

Technical Field

The invention belongs to the field of medicines and medical instruments, and relates to a double-chamber syringe and a charging method. In particular, the present invention relates to a dual chamber syringe prefilled with a lyophilized drug. The invention also relates to a method for filling the double-chamber syringe.

Background

For powder injection medicines with unstable chemical state and heat sensitivity, penicillin bottles are usually adopted as containers for containing the medicines, and the medicines are freeze-dried and then packaged by rolling covers, so that long-time preservation can be realized. When in use, a hospital nurse usually uses the injection to dissolve the medicine according to the proportion, and the configuration of the injection medicine is completed. This method requires professional, skilled operators (such as nurses) and a clean environment, and the configuration process takes a certain amount of time, which is not suitable for use by out-of-hospital patients or emergency situations.

At present, some solid-liquid double-chamber syringes in the market can solve the problems, and can rapidly mix injection liquid and medicine powder when in use, so as to realize one-time completion of medicine dispensing and injection. Although the operation process of the syringe is simple, the processes of medicine production and preparation and split charging of the syringe are complex, the environmental requirement is high, and the quality control is difficult. The common medicine split charging mode of this type of syringe is to fill the injection in advance, then sterilize at high temperature, and finally fill the medicine powder manually. In the method, because of high-temperature sterilization, some water can remain in sealing parts such as rubber plugs and the like, and the water can easily permeate into medicine powder to influence the stability of the medicine; and the operation of manual accurate quantitative filling is relatively complicated, and the medicine subpackaging operability of the injector is poor. In addition, the preparation process of the medicine powder is complex, and the medicine is required to be crushed and collected on the basis of freeze-drying of the medicine, so that on one hand, strict clean environment is required to ensure the sterility of the medicine preparation process; secondly, the medicine needs to be exposed in the air for a long time in the process of crushing and quantitative subpackaging, and the environment needs to be dried, so that the influence on the stability of the medicine caused by the exposure of the medicine in humid air is avoided. Therefore, the conventional solid-liquid dual-chamber syringe is easy to operate, but has a complicated process for filling the drug and poor operability.

At present, there is a need to develop new dual chamber syringes.

Disclosure of Invention

The inventor prepares a drug-preloaded double-chamber syringe with a front chamber and a rear chamber in a cylindrical structure through intensive research and creative labor, wherein the front chamber is a container for a drug and is lyophilized together with a liquid drug, and the syringe is directly assembled after the lyophilization is finished; the rear chamber cartridge is loaded with a fixed amount of a solvent for injection. When the medicine is not used, the front chamber cylinder and the rear chamber cylinder are mutually isolated, and the medicine in the front chamber is kept in a dry solid state; when in use, the front chamber cylinder is communicated with the rear chamber cylinder, and the injection enters the front chamber cylinder to be mixed with the solid medicine. The following invention is thus provided:

one aspect of the invention relates to an injector comprising an injector head (21), a syringe (10), a plunger (16) and a push rod (32), wherein:

the injection cylinder (10) comprises a front chamber cylinder (11) and a rear chamber cylinder (13), wherein the front chamber cylinder (11) is detachable;

preferably, the front cartridge (11) can be used for containing a liquid and for lyophilization.

In some embodiments of the invention, the injector is provided with a rubber plug (14) in the front chamber cylinder (11).

In some embodiments of the invention, the syringe is characterized in that a partition plug (15) is arranged in the rear chamber cylinder (13) and close to the proximal end (13a) of the rear chamber cylinder (13) for partitioning the front chamber cylinder (11) and the rear chamber cylinder (13); and a plunger (16) located at the distal end (13b) of the rear chamber barrel (13).

In some embodiments of the invention, the syringe is described wherein the vertical distance from the plug (14) to the proximal end (11a) of the anterior chamber tube (11) is denoted as L, L being 1-3 times the thickness of the stopper plug 15;

preferably, L is 1.2 to 1.8 times (e.g., 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, or 1.8 times) the thickness of the partition plug 15;

more preferably, L is 1.4 to 1.6 times the thickness of the partition plug 15.

In some embodiments of the invention, the injector is provided, wherein the front chamber cylinder (11) and the rear chamber cylinder (13) have the same diameter and are both independent tubes.

In some embodiments of the invention, the syringe is one in which the distal end (11b) of the front barrel (11) and the proximal end (13a) of the rear barrel (13) are connected by a connecting barrel (12), the connecting barrel (12) having the same diameter as the front barrel (11) and the rear barrel (13).

In some embodiments of the invention, the syringe is described wherein the length of the central portion of the connecting barrel (12) is expressed as H, which is 1.2 to 1.8 times (e.g., 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, or 1.8 times) the thickness of the stopper 15, preferably 1.4 to 1.6 times, more preferably 1.5 times;

preferably, H is less than the sum of the thicknesses of the partition plug 15 and the push plug 16.

In some embodiments of the invention, the injector is provided with one or more communication grooves (12a) at the middle part of the connecting cylinder (12); the communicating groove (12a) is used for communicating the front chamber cylinder (11) and the rear chamber cylinder (13), and when the partition plug (15) slides to the middle part of the connecting cylinder (12), the front chamber cylinder (11) is communicated with the rear chamber cylinder (13);

preferably, the number of communication channels (12a) is 1-6, more preferably 2, 3 or 4.

In some embodiments of the invention, the syringe is provided with one or more damping ribs (12b) in the middle of the connecting cylinder (12);

preferably, the number of damping ribs (12b) is 1-6, more preferably 2, 3 or 4.

In some embodiments of the invention, the syringe is described wherein the vertical distance from the stopper (15) to the proximal end (13a) of the rear chamber barrel (13) is denoted as M, M being 0.5 to 1 times the thickness of the stopper (15).

In some embodiments of the invention, the injector is described wherein the proximal end (10a) of the barrel (10) is connected to an injector head (21).

In some embodiments of the invention, the syringe, wherein,

the inner diameter D of the inner cavity of the injection head (21) is 5 to 10 percent larger than the outer diameter of the rubber plug (14); and

the height N of the inner cavity of the injection head (21) is larger than the thickness of the rubber plug (14), and preferably N is 1.2-1.4 times of the thickness of the rubber plug (14).

In some embodiments of the invention, the syringe, wherein,

the periphery and the bottom of the inner cavity of the injection head (21) are provided with grooves (21a), the grooves (21a) are communicated with a needle nozzle (21c),

preferably, the number of grooves (21a) is 1-6, preferably 2, 3 or 4;

in some embodiments of the invention, the injector is characterized in that at least 2 ribs (21b) are arranged around the inner cavity of the injection head (21), the ribs are arranged at equal intervals circumferentially, and the diameter of the inner circle surrounded by all the ribs is equal to the diameter of the rubber plug (14);

preferably, the number of ribs is 3-12, preferably 3-6.

In some embodiments of the invention, the injector is provided, wherein the injection head (21) is connected with the injection needle seat (22); an injection needle seat (22) is used for fixing an injection needle (23);

preferably, the injection head (21) is connected with the injection needle seat (22) in a threaded mode;

preferably, the injection needle holder (22) is also connected to an injection needle sleeve (24).

In some embodiments of the invention, the injector is described wherein a plunger (16) within the rear chamber barrel (13) is connected to a pushrod (32);

preferably, the push rod (32) is connected with the push plug (16) through a thread form;

preferably, a finger grip (31) is connected to the distal end (10b) of the syringe (10);

preferably, the finger grip (31) and the push rod (32) constitute the structure of the single-hand injection operation of the injector;

preferably, a water sucking ring (33) is arranged on one side of the push rod (32) close to the push plug (16), and the push rod (32) penetrates through the finger handle (31) to be connected with the water sucking ring (33) and the push plug (16);

preferably, the diameter of the middle opening of the finger handle (31) is smaller than the diameters of the water suction ring (33) and the push plug (16).

In some embodiments of the invention, the syringe is characterized in that the container (101) formed by the front chamber tube (11) and the rubber plug (14) can be used for containing liquid medicine and freeze-drying;

preferably, the solid drug obtained after lyophilization can be used directly for packaging of syringes.

In some embodiments of the invention, the syringe, wherein the rear chamber barrel (13) and the container (102) of the shut off plug (15) and the push plug (16) are used for pre-filling with injectate.

Another aspect of the invention relates to a method of charging a syringe according to any of the invention, comprising the steps of:

filling a container (101) formed by a sterilized front chamber tube (11) or the sterilized front chamber tube (11) and a rubber plug (14) with a solid medicine or a liquid medicine; preferably, the liquid medicament is lyophilized in a sterile clean environment to obtain a solid medicament;

assembling the sterilized rear chamber cylinder (13), a push plug (16), an optional finger handle (31), a push rod (32) and an optional water absorption ring (33) to form a container (102);

thirdly, under the sterile clean environment, the container (102) is filled with injection, and after liquid transfer, a partition plug (15) is arranged.

In some embodiments of the invention, the syringe is a medical syringe.

In some embodiments of the present invention, the drug in the pre-chamber is a solid drug or a liquid drug, preferably a liquid drug suitable for lyophilization or a solid drug obtained after lyophilization, such as a lyophilized formulation, preferably a lyophilized powder injection.

In some embodiments of the invention, the front chamber contains an injection solution.

In the present invention, the term "proximal" means an end near an injection head or needle, if not otherwise specified; the term "distal" refers to the end distal to the injection head or needle.

In the present invention, the term "diameter" means a passable diameter, which is equal to the inner diameter in many cases, unless otherwise specified. The inner diameter of the cylinder for 11 and 13; 12 are internally ribbed with a diameter equal to the diameter (or internal diameter) of the internal main circle. The size of the drift diameter is not particularly limited, and can be designed according to requirements, for example, the drift diameter can be larger, the dosage can be smaller and the drift diameter can be smaller if the dosage is larger. In some embodiments of the invention, each of said channels independently has a diameter of from 3 to 30mm, preferably from 5 to 20mm, more preferably from 5 to 15mm, particularly preferably from 8 to 12mm, for example 8mm, 9mm, 10mm, 11mm or 12 mm.

In some embodiments of the invention, the pre-chamber cartridge is 1-10cm, preferably 2-8cm, more preferably 3-6cm in length in order to facilitate lyophilization and containment of a quantity of drug.

In some embodiments of the invention, the rear chamber barrel is approximately 1-6cm, preferably 2-5cm, more preferably 3-4cm in length in order to accommodate the injection vehicle in which the drug is dissolved.

In the present invention, the term "injection solution" may contain an active ingredient or may be an injection vehicle containing no active ingredient, if not otherwise specified; preferably, the vehicle for injection does not contain an active ingredient.

The injection cylinder for pre-loading the medicament consists of a front cylinder, a connecting cylinder and a rear cylinder, wherein the front cylinder is used for loading freeze-dried solid medicament, and the rear cylinder is loaded with injection solvent for dissolving or dispersing the solid medicament; the front chamber cylinder and the rear chamber cylinder are connected through the connecting cylinder, a plurality of rubber plugs are arranged in the middle of the connecting cylinder and used for separating the front chamber cylinder from the rear chamber cylinder, and the rubber plugs can slide in the whole injection cylinder and ensure the front-back air tightness; the other end of the front chamber cylinder is connected with an injection needle kit, and the other end of the rear chamber cylinder is connected with an injector push rod and a finger handle; the connecting cylinder is provided with a plurality of side channels, when the push rod pushes the injection liquid to move forwards, the middle rubber plug reaches the connecting sleeve, the front cylinder is communicated with the rear cylinder, and the injection liquid enters the front cylinder from the rear cylinder to be mixed with the solid medicine, so that the preparation of the medicine before injection is finished. The front cylinder can be directly placed into a freeze dryer as a container for containing liquid medicines, and can be directly assembled with other components to form an injector after freeze drying is finished. The invention reduces the preparation process flow of the solid powder after the freeze-drying of the medicine, realizes that the solid medicine and the injection are pre-filled in the same injector, and can realize the one-time completion of medicine dispensing and injection. The operation is simple, the pollution in the process of medicine packaging and dispensing is avoided, and the preparation and use costs are low.

Advantageous effects of the invention

The double-chamber injector can mix the injection with the freeze-dried medicine when in use, realizes one-time completion of medicine dispensing and injection, and simultaneously solves the difficulty of medicine split charging of the solid-liquid double-chamber injector.

Drawings

In the following FIGS. 1 to 7E, unless otherwise specified, the reference numerals have the following meanings:

1, a drug; 1a, liquid medicine; 1b, a solid drug;

2, injection;

10, an injection cylinder; 10a, a syringe barrel proximal end; 10b, a distal barrel end;

11, a front chamber cylinder; 11a, the anterior barrel proximal end (same as 10 a); 11b, the front barrel distal end;

12, connecting the cylinder; 12a, a communication groove; 12b, damping ribs;

13, a rear chamber cylinder; 13a, a rear chamber barrel proximal end; 13b, rear chamber barrel distal end (same as 10 b);

14, a rubber plug; 15, a partition plug; 16, a plunger;

21, an injection head; 21a, a groove; 21b, ribs; 21c, a needle mouth;

22, an injection needle seat; 23, an injection needle; 24, injecting needle sleeve;

31, a finger grip; 32, a push rod; 33, a water absorption ring;

101, a space for containing medicine in the front cylinder; 102, a space for containing injection liquid in the rear chamber cylinder;

l, the distance of the plug 14 from the proximal end 11a of the anterior barrel 11;

m, the distance between the partition plug 15 and the port of the rear chamber cylinder 13;

n, the height of the cavity of the injection head 21;

d: the inner diameter of the lumen of the injector head 21.

FIG. 1: in one embodiment of the invention, the dual chamber syringe is shown in longitudinal cross-section.

FIG. 2A: the front chamber cylinder is a schematic longitudinal section before the medicament is lyophilized (containing liquid medicament). A front chamber tube 11 and a rear chamber tube 13.

FIG. 2B: the front cylinder is a schematic longitudinal section of the medicament after freeze-drying (containing solid medicament).

FIG. 3A: a schematic longitudinal cross-section of the connector barrel.

FIG. 3B: a schematic cross-sectional view of the connector barrel.

FIG. 4: a schematic longitudinal section of a rear chamber barrel loaded with injectate.

FIG. 5A: the injection head is shown in longitudinal section.

FIG. 5B: fig. 5A is a partially enlarged view.

FIG. 5C: a schematic cross-sectional view of an injection head.

FIG. 6: the connecting cylinder connects the front and rear chambers in a longitudinal cross-sectional view.

FIG. 7A: the syringe is in a state before use (longitudinal cross-sectional view).

FIG. 7B: the state in which the front chamber tube 11 and the rear chamber tube 13 of the syringe communicate with each other (schematic longitudinal sectional view).

FIG. 7C: the injection liquid 2 in the rear chamber tube 13 is completely introduced into the front chamber tube 11 (longitudinal cross-sectional view).

FIG. 7D: the injector is in a state of being evacuated of the internal gas (longitudinal sectional view).

FIG. 7E: syringe conditions (longitudinal cross-sectional schematic) available for injection.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following detailed description is illustrative of the present invention only and should not be taken as limiting the scope of the present invention.

(1) Structure related to syringe

As shown in fig. 1, a syringe 10 for pre-loading a medicament consists of a front chamber barrel 11, a connecting barrel 12 and a rear chamber barrel 13; the distal end 11b of the front chamber tube 11 and the proximal end 13a of the rear chamber tube 13 are connected by a connecting tube 12; a rubber plug 14 is arranged in the front cylinder 11, and the distance from the near end 11a of the front cylinder 11 is L; two rubber plugs are arranged in the rear chamber tube 13, one is a partition plug 15 close to the proximal end 13a of the rear chamber tube 13 and is used for partitioning the front chamber tube 11 and the rear chamber tube 13; the other is a plunger 16 located at the distal end 13b of the rear chamber barrel 13; the drift diameters of the front chamber tube 11, the connecting tube 12 and the rear chamber tube 13 are the same, and the rubber plug 14, the partition plug 15 and the push plug 16 can slide in the front chamber tube 11, the connecting tube 12 and the rear chamber tube 13 and can keep air tightness.

The proximal end 10a of barrel 10 (also proximal end 11a of front barrel 11) is connected to injector head 21; the injection head 21 is connected with the injection needle seat 22, and the two are connected in a threaded mode; the needle holder 22 holds the needle 23 and is also connected to a needle sheath 24 for protecting the needle 23.

Distal end 10b of barrel 10 (and also distal end 13b of rear chamber barrel 13) is connected to finger grip 31; the push plug 16 in the rear chamber barrel 13 is connected with a push rod 32, and the finger handle 31 and the push rod 32 form a structure for single-hand injection operation of the injector; the push rod 32 is connected with the push plug 16 through threads and the like; a water-absorbing ring 33 is provided on the side of the plunger 32 adjacent the plunger 16.

The more detailed structural scheme is described as follows:

as shown in fig. 2A and 2B, the container 101 formed by the front cartridge 11 and the rubber plug 14 can be used for containing the liquid medicine 1a and freeze-drying; the freeze-dried solid medicine 1b can be directly used for packaging a syringe; the distance between the rubber plug 14 and the near end 11a of the front cylinder 11 is L; preferably, L is 1-3 times the thickness of the partition plug 15, more preferably, L is 1.2-1.8 times, e.g., 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, or 1.8 times the thickness of the partition plug 15; particularly preferably 1.5 times.

Without being limited by theory, the plug 14 also moves forward when the partition plug 15 moves forward, and it is required to ensure that the plug 14 is completely or partially still in the front chamber tube 11 when the partition plug 15 just completely enters the connecting tube 12, so as to prevent the front chamber tube 11 from being communicated with the injection head 21 in the front and rear chamber mixing process. If L is too short, the rubber plug 14 enters the injection head 21, and the front chamber tube 11 is communicated with the injection head 21; if L is too long, although the function is not affected, the useless length of the front chamber cylinder is increased, and the whole injector becomes long.

In some embodiments of the invention, L is such that the plug 14 is fully or partially still in the front chamber tube 11 just prior to the full entry of the plug 15 into the connector tube 12.

In some embodiments of the present invention, L is such that the front cylinder 11 is not in communication with the injector head 21 just when the shut-off plug 15 has fully entered the connector cylinder 12.

As shown in fig. 3A and 3B, the connecting cylinder 12 is used to connect the front cylinder 11 and the rear cylinder 13, and the length H of the middle portion of the connecting cylinder 12 is greater than the thickness of the blocking plug 15 (for example, the length H is 1.2-1.8 times, preferably 1.5 times, the thickness of the blocking plug 15); preferably, the length H is less than the sum of the thicknesses of the shut-off plug 15 and the push plug 16. A communication groove 12a and a damping rib 12b are arranged in the middle of the connecting cylinder 12; the communicating groove 12a is used for communicating the front chamber cylinder 11 and the rear chamber cylinder 13, and when the isolating plug 15 slides to the middle part of the connecting cylinder 12, the front chamber cylinder 11 is communicated with the rear chamber cylinder 13; the number of the communicating grooves 12a is 2 to 4, excessive or insufficient is not suitable, if the number is excessive, the residual injection liquid in the communicating grooves is excessive, if the number is insufficient, the flow of the injection liquid is slow, and the operation needs to be performed by great force; the damping ribs 12b are used for increasing the resistance of the partition plug 15 passing through the connecting cylinder 12, so that the phenomenon that the partition plug 15 directly rushes through the connecting cylinder 12 to play a role of communicating the front chamber cylinder with the rear chamber cylinder when too much force is applied during operation is avoided; the number of the damping ribs 12b is preferably 4.

Without being limited by theory, the diameter of the inner ring encircled by the damping rib 12b of the connecting cylinder 12 is smaller than the outer diameter of the partition plug 15, and the main function is to slow down the movement of the partition plug and prevent the partition plug 15 from moving to rush through the connecting cylinder 12 at a stroke.

FIG. 4 shows a container 102 consisting of a rear chamber tube 13, a blocking plug 15 and a pushing plug 16, which can be used for prefilling the injection solution 2; the blocking plug 15 is positioned at the near end 13a of the rear chamber cylinder 13 and has a length M from the port 13a of the rear chamber cylinder 13; preferably, the length M is 0.5 to 1 times the thickness of the partition plug 15.

Without being limited by theory, in the assembling process of the injector, M is not suitable to be 0, otherwise the partition plug 15 is easy to fall out due to error touch, or the partition plug 15 enters the connecting cylinder 12 due to error touch, so that the front chamber and the rear chamber are communicated; m should not be too long, otherwise cause the syringe overall length too long. It is preferable that the length M is 0.5 to 1 times the thickness of the blocking plug 15.

As shown in figure 1, the push rod 32 passes through the finger handle 31 to be connected with the water sucking ring 33 and the push plug 16, and the diameter of the middle opening of the finger handle 31 is smaller than the diameters of the water sucking ring 33 and the push plug 16, so that the push rod 32 can be prevented from being pulled out by mistake; when the plunger 16 passes through the middle of the connecting cylinder 12, the water absorption ring 33 can absorb the residual liquid in the communicating groove 12a, and the residual liquid is prevented from flowing out of the injector.

As shown in fig. 5A, 5B and 5C, the inner diameter D of the inner cavity of the injection head 21 is 5% to 10% larger than the outer diameter of the rubber plug 14, which can ensure that the syringe is easy to operate during injection and reduce the residue of liquid injection medicine in the syringe; the height N of the inner cavity of the injection head 21 is larger than the thickness of the rubber plug 14 and is about 1.2 to 1.4 times of the thickness of the rubber plug; the periphery and the bottom of the inner cavity of the injection head 21 are provided with grooves 21a, the grooves 21a are communicated with needle nozzles 21c, the function of the grooves is to ensure that liquid can bypass the rubber plug 14 and enter the injection needles 23, and the number of the grooves 21a is 2-4; the ribs 21b are arranged around the inner cavity of the injection head 21, the number of the ribs is 3-6, the ribs are arranged at equal intervals and are arranged circumferentially, the diameter of the enclosed inner circle is equal to that of the rubber plug 14, the function of the ribs is to ensure that the rubber plug 14 keeps coaxial in the inner cavity of the injection head 21 (the rubber plug 14 does not deflect in the injection head 21), and the phenomenon that excessive injection liquid is remained in the cavity due to deflection of the rubber plug 14 is avoided.

(2) Method of filling a syringe

The sterilized antechamber cylinder 11 and the rubber plug 14 form a container 101, as shown in fig. 2A, the container 101 contains liquid medicine 1a, and is lyophilized in a sterile clean environment to form solid block medicine, and fig. 2B is the antechamber state for loading lyophilized material.

After the sterilized rear chamber barrel 13, the push plug 16, the finger handle 31, the push rod 32 and the water absorption ring 33 are assembled, a container 102 is formed, and fig. 4 is shown; under a sterile and clean environment, the container 102 may be filled with the injection solution 2 manually or by means of another liquid transfer device, and the partition plug 15 is inserted after the liquid transfer, and fig. 4 shows a state of a rear chamber in which the injection solution is loaded.

FIG. 6 (the entire FIG. 6 shows the syringe 10) is a state where the front and rear chambers are connected by the connecting cylinder 12, i.e., the filling of the syringe 10 with the medicine and the injection liquid is completed; assembly of the needle segment assembly continues in a sterile, clean environment, eventually completing assembly of the syringe.

(3) Methods of use/injection with respect to syringes

FIG. 7A shows the syringe in a pre-use condition, in which the needle of the syringe is oriented vertically upwards and the needle sheath 24 is removed; the push rod 32 is pushed, and the rubber plug 14, the partition plug 15, the push plug 16 and the injection liquid 2 in the injection tube 10 move forwards; when the block plug 15 moves to the middle portion of the connection cylinder 12, as shown in fig. 7B, the front chamber cylinder 11 and the rear chamber cylinder 13 communicate through the communication groove 12a of the connection cylinder 12; the push rod 32 continues to push, the rubber plug 14 and the push plug 16 move forward, the injection liquid 2 enters the front barrel 11, the rubber plug 14 enters the inner cavity of the injection head 21, and the gas in the injection barrel 10 is discharged through the injection needle 23, as shown in fig. 7C; when the push plug 16 reaches the blocking plug 15, the injection liquid 2 completely enters the front chamber tube 11, and the freeze-dried medicine 1b is mixed and dissolved with the injection liquid 2 to form the injection liquid 3, which is shown in fig. 7D; the pushrod 32 continues forward to vent the air from the front barrel 11, creating an injector condition available for injection, as shown in fig. 7E.

Although specific embodiments of the invention have been described in detail, those skilled in the art will appreciate. Various modifications and substitutions of those details may be made in light of the overall teachings of the disclosure, and such changes are intended to be within the scope of the present invention. The full scope of the invention is given by the appended claims and any equivalents thereof.

Claims (19)

1. An injector comprising an injector head (21), a syringe (10), a plunger (16) and a push rod (32), wherein:

the injection cylinder (10) comprises a front chamber cylinder (11) and a rear chamber cylinder (13), wherein the front chamber cylinder (11) is detachable;

preferably, the front cartridge (11) can be used for containing a liquid and for lyophilization.

2. The syringe according to claim 1, wherein a rubber plug (14) is provided in the front chamber tube (11).

3. A syringe according to any one of claims 1 to 2, in which the rear barrel (13) has a shut-off plug (15) therein adjacent the proximal end (13a) of the rear barrel (13) for shutting off the front barrel (11) from the rear barrel (13); and a plunger (16) located at the distal end (13b) of the rear chamber barrel (13).

4. A syringe according to claim 3, wherein the vertical distance of the plug (14) from the proximal end (11a) of the anterior chamber barrel (11) is denoted L, L being 1-3 times the thickness of the stopper (15);

preferably, L is 1.2 to 1.8 times the thickness of the partition plug 15;

more preferably, L is 1.4 to 1.6 times the thickness of the partition plug 15.

5. Syringe according to any one of claims 1 to 4, in which the front (11) and rear (13) chambers have the same diameter and are each a separate tube.

6. A syringe according to any one of claims 1 to 5, wherein the distal end (11b) of the front barrel (11) and the proximal end (13a) of the rear barrel (13) are connected by a connector barrel (12), the connector barrel (12) having the same path as the front barrel (11) and the rear barrel (13).

7. Syringe according to claim 6, in which the length of the middle part of the connecting barrel (12) is expressed as H, H being 1.2-1.8 times, preferably 1.4-1.6 times, the thickness of the shut-off plug 15;

preferably, H is less than the sum of the thicknesses of the shut off plug 15 and the push plug 16.

8. A syringe according to any one of claims 6 to 7, wherein the connecting barrel (12) is provided, in its intermediate portion, with one or more communicating grooves (12 a); the communicating groove (12a) is used for communicating the front chamber cylinder (11) and the rear chamber cylinder (13), and when the partition plug (15) slides to the middle part of the connecting cylinder (12), the front chamber cylinder (11) is communicated with the rear chamber cylinder (13);

preferably, the number of communication channels (12a) is 1-6, more preferably 2, 3 or 4.

9. A syringe according to any one of claims 6 to 8, wherein the connecting barrel (12) is provided with one or more damping ribs (12b) in the middle;

preferably, the number of damping ribs (12b) is 1-6, more preferably 2, 3 or 4.

10. A syringe according to any one of claims 3 to 9, in which the vertical distance of the shut-off stopper (15) from the proximal end (13a) of the rear-chamber barrel (13) is denoted M, M being 0.5 to 1 times the thickness of the shut-off stopper (15).

11. Syringe according to any of claims 1 to 10, wherein the proximal end (10a) of the barrel (10) is connected to an injection head (21).

12. The syringe of claim 11,

the inner diameter D of the inner cavity of the injection head (21) is 5 to 10 percent larger than the outer diameter of the rubber plug (14); and

the height N of the inner cavity of the injection head (21) is larger than the thickness of the rubber plug (14), and preferably N is 1.2-1.4 times of the thickness of the rubber plug (14).

13. The injector of any one of claims 11 to 12,

the periphery and the bottom of the inner cavity of the injection head (21) are provided with grooves (21a), the grooves (21a) are communicated with a needle nozzle (21c),

preferably, the number of grooves (21a) is 1 to 6, preferably 2, 3 or 4.

14. A syringe according to any one of claims 11 to 13, wherein the injector head (21) has at least 2 ribs (21b) around its internal cavity, said ribs being arranged circumferentially at equal intervals and all the ribs enclosing an internal circle of diameter equal to the diameter of the plug (14);

preferably, the number of ribs is 3-12, preferably 3-6.

15. A syringe according to any one of claims 11 to 14, wherein the injection head (21) is associated with an injection needle holder (22); an injection needle (23) is fixed on the injection needle seat (22);

preferably, the injection head (21) is connected with the injection needle seat (22) in a threaded mode;

preferably, the injection needle holder (22) is also connected to an injection needle sleeve (24).

16. A syringe according to any of claims 1 to 15, in which a plunger (16) within the rear chamber barrel (13) is connected to a push rod (32);

preferably, the push rod (32) is connected with the push plug (16) through a thread form;

preferably, a finger grip (31) is attached to the distal end (10b) of the barrel (10);

preferably, the finger grip (31) and the push rod (32) constitute the structure of the single-hand injection operation of the injector;

preferably, a water sucking ring (33) is arranged on one side of the push rod (32) close to the push plug (16), and the push rod (32) penetrates through the finger handle (31) to be connected with the water sucking ring (33) and the push plug (16);

preferably, the diameter of the middle opening of the finger handle (31) is smaller than the diameters of the water suction ring (33) and the push plug (16).

17. Syringe according to any one of claims 1 to 16, in which the container (101) of the pre-chamber cartridge (11) and the stopper (14) is intended to contain a liquid drug and to be lyophilized;

preferably, the solid drug obtained after lyophilization can be used directly for packaging of syringes.

18. A syringe according to any one of claims 1 to 17, in which the rear chamber barrel (13) and the container (102) of the shut-off plug (15) and the plunger (16) are adapted to be prefilled with an injection solution.

19. Method of charging the syringe of any one of claims 1 to 18, comprising the steps of:

filling a container (101) formed by a sterilized front chamber tube (11) or the sterilized front chamber tube (11) and a rubber plug (14) with a solid medicine or a liquid medicine; preferably, the liquid medicament is lyophilized in a sterile clean environment to obtain a solid medicament;

assembling the sterilized rear chamber cylinder (13), a push plug (16), an optional finger handle (31), a push rod (32) and an optional water absorption ring (33) to form a container (102);

thirdly, under the sterile clean environment, the container (102) is filled with the injection, and the partition plug (15) is filled after liquid transfer.

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