Pre-filled syringe

Abstract

The pre-filled syringe comprises a needle tube, a plunger and an injection head, the injection head is arranged at the front end of the needle tube, the plunger is arranged in the needle tube in a sealed mode, a pre-filled medicament containing space is formed between the plunger and the injection head, a filter buffer is arranged between the tail end of the needle tube and the plunger, and the filter buffer is arranged at the tail end of the needle tube. A filtering hole is formed in the filtering buffering object, a buffering cavity is formed between the plunger and the filtering buffering object, and the buffering cavity is communicated with the outside through the filtering hole. According to the pre-filled syringe, in the cryopreservation and redissolution process, gas in the buffer cavity can be slowly exchanged with the outside through the filter holes with the hole diameter being only 0.22 microns until pressure balance is achieved. In the process, the influence of pressure change caused by rapid temperature change of the medicament and the plunger can be relieved, the situation that in the prior art, displacement of the plunger is easily caused by rapid pressure change is avoided, and therefore the consequence of medicament pollution caused by sealing failure is completely eradicated.

Description

Technical Field

[0001] The utility model relates to the field of medical instruments, in particular to a prefilled syringe. Background Art

[0002] Cell and gene therapy (CGT) products in clinical applications typically include gene therapy products, vaccines, stem cell gene therapy products, immune cell therapy products, etc. These products are of great value in treating human diseases. These drugs are extremely sensitive to temperature, and improper storage conditions can cause drug failure and reduce efficacy. In terms of the formulation form of cell therapy products, although fresh cell preparations have their advantages, with the advancement of industry research and technology, the mainstream view is gradually tending to adopt frozen forms. Frozen cell preparations are more in line with the basic characteristics of drug preparations, are conducive to arranging production, completing necessary finished product testing and release procedures, support multi-dose production and large-scale promotion and application, and are also more in line with the form required for new drug applications (NDAs).

[0003] The industry's primary form of aseptic cryopreservation packaging for cell and gene therapy drugs currently utilizes vials. After aseptic filling, stoppering, and capping, the vials are cryopreserved and then stored and transported at low temperatures. During clinical use, medical staff reconstitute the vial and administer the medication to the patient using a syringe, a process known as the "vial + syringe" method.

[0004] However, vial packaging has shortcomings when it comes to low-temperature storage. At low temperatures, expansion of the bottle and stopper, as well as brittle aluminum caps, affect the sealing performance. Consequently, the integrity and sealing of vial packaging are challenged at low temperatures. Low-temperature capping processes are difficult to develop and cannot fully meet the CGT industry's low-temperature storage requirements.

[0005] While prefilled syringes (PFS) offer advantages such as convenience, dosage accuracy, and safety at room temperature, the current packaging process for prefilled syringes, primarily consisting of filling and stoppering, cannot meet the packaging requirements of the ultra-low-temperature CGT industry for high-value-added drugs and temperature-sensitive drugs requiring cryopreservation. Cryopreservation involves a temperature fluctuation process between freezing and reconstitution. During this drastic temperature change, the stopper can shift, compromising the seal of the drug packaging and causing leakage, posing a high risk of drug contamination by particulates and microorganisms.

[0006] Therefore, both vials and prefilled syringes have limitations in low-temperature storage and cannot fully meet the CGT industry's requirements for low-temperature storage of drugs. The industry urgently needs to develop a new packaging format that can adapt to low-temperature storage while ensuring drug quality and safety, in order to promote the clinical application and industrial development of CGT products. Summary of the Invention

[0007] In order to solve the above problems, the present invention provides a prefilled syringe that can have good stability in a low-temperature storage environment and avoid sealing problems in both frozen storage and reconstitution states.

[0008] In order to achieve the above-mentioned purpose, the utility model is designed into a prefilled syringe, comprising a needle tube, a plunger and an injection head, wherein the injection head is arranged at the front end of the needle tube, the plunger is sealingly arranged in the needle tube, and forms a storage space for the prefilled medicine between the plunger and the injection head, a filter buffer is provided between the end of the needle tube and the plunger, the filter buffer is provided with a filter hole, a buffer cavity is formed between the plunger and the filter buffer, and the buffer cavity is connected to the outside through the filter hole.

[0009] A further solution is that the filter buffer is a filter buffer membrane composed of a medical microporous filter material with filter pores having a pore size of less than or equal to 0.22 μm.

[0010] Another further solution is that the filter buffer is a filter buffer plug composed of a medical microporous filter material with filter pores having a pore size of less than or equal to 0.22 μm.

[0011] In order to prevent the filter buffer plug from entering the needle tube during production and before using the prefilled injection and becoming unable to be removed, the filter buffer plug is composed of two parts, a matching plug body and a tail flange, through an integrated forming structure. The matching plug body matches the inner diameter of the needle tube, and the tail flange matches the tail end face of the needle tube.

[0012] In some cases, the filter buffer plug can also be composed of a mating plug body and a tail flange, where the mating plug body mates with the inner diameter of the needle tube, and the tail flange mates with the tail end face of the needle tube. The mating plug body is composed of medical microporous filter material with a pore size of 0.22 μm or less. In some technical solutions, a vent hole is also required in the tail flange, through which the mating plug body is exposed to the outside air.

[0013] In order to ensure the stability and sealing of the cooperation between the filter buffer plug and the needle tube, a sealing flange is provided on the outer wall of one end of the filter buffer plug close to the plunger, and the sealing flange is annular or spiral.

[0014] In order to adapt to various usage scenarios, the injection head is provided with an injection needle or a Luer connector.

[0015] The prefilled syringe designed by the present invention and the corresponding prefilled syringe obtained, creatively add a filter buffer behind the plunger to form a buffer cavity. During the freezing and re-dissolving process, the gas in the buffer cavity can slowly exchange with the outside through the filter hole with a pore size of only 0.22um until the pressure balance is achieved. This process can slow down the impact of pressure changes on the medicine and the plunger caused by rapid temperature changes, avoiding the situation in the prior art where the plunger is easily displaced due to rapid pressure changes, thereby eliminating the consequences of medicine contamination caused by seal failure. It should be specially noted that the filter hole less than or equal to 0.22um not only plays the role of gas exchange to buffer pressure changes, but also filters the air entering the buffer cavity, preventing particles and microorganisms from entering the buffer cavity. The buffer cavity can always maintain a sterile and pure state. Therefore, even if the plunger is accidentally displaced due to pressure changes, it will not cause any contamination to the medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of the prefilled syringe equipped with a filter buffer plug produced in Example 1.

[0017] Figure 2 This is a schematic diagram of the structure of the prefilled syringe equipped with a filter buffer membrane produced in Example 1.

[0018] Figure 3 This is a schematic diagram of the structure of the prefilled syringe using a Luer connector produced in Example 2. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0020] Example 1.

[0021] like Figure 1 、 Figure 2 As shown, the production process of the prefilled syringe described in this embodiment includes the following steps: honeycomb prefilled syringe material preparation and cleaning - outer packaging surface disinfection - outer packaging removal - high temperature heating and film tearing - liner removal - aseptic filling of the medicine 4 - installation of the plunger 3 - installation of the filtration buffer - freezing at -30°C to -196°C - packaging.

[0022] The obtained prefilled syringe includes a needle tube 1, a plunger 3 and an injection head. The injection head is arranged at the front end of the needle tube 1, and an injection needle 2 is provided on it. The plunger 3 is sealed in the needle tube 1 and forms a storage space for the prefilled medicine 4 between the plunger 3 and the injection head. A filter buffer is provided between the end of the needle tube 1 and the plunger 3, and a buffer cavity 9 is formed between the filter buffer and the plunger 3.

[0023] The filter buffer is provided with a filter buffer plug 5 composed of a medical microporous filter material with a pore size less than or equal to 0.22 μm. Figure 1 As shown, the buffer cavity 9 is connected to the outside through a 0.22 μm filter hole. Medical microporous filter materials are generally made of PP / PTFE. The filter buffer plug is specifically constructed of two integrally formed parts: a mating plug body 7 and a tail flange 8. The mating plug body 7 mates with the inner diameter of the needle tube 1, and the tail flange 8 mates with the tail end face of the needle tube 1.

[0024] The cooperation between the tail flange 8 and the end face of the needle tube 1 has two main functions:

[0025] 1. As a limit to prevent the filter buffer plug 5 from entering the needle tube 1;

[0026] 2. Serving as a connector for removing the filter buffer plug 5 , it is convenient for the user to remove the filter buffer plug 5 during use.

[0027] If necessary, a spiral sealing flange 6 is provided on the outer wall of the end of the filter buffer plug 5 near the plunger 3, i.e., on the outer wall of the mating plug body 7. The spiral sealing flange 6 is characterized by its ability to more smoothly allow the filter buffer plug 5 to enter the interior of the needle tube 1, thereby forming the aforementioned buffer cavity 9. It also achieves an interference fit between the mating plug body 7 and the needle tube 1, effectively and stably connecting the entire filter buffer plug 5 to the needle tube 1 and providing a good sealing effect, thereby ensuring that all internal and external gas exchange passes through the filter holes in the filter buffer plug 5.

[0028] In some technical solutions, in order to save costs, the filter buffer can also be a filter buffer membrane 51, such as Figure 2 As shown, the filter buffer membrane 51 has a tear edge protruding from the end of the needle tube 1, so that the user can tear off the filter buffer membrane 51 directly by hand, thereby exposing the opening at the tail of the needle tube 1, so that the plunger rod can enter the interior of the needle tube 1 and connect with the plunger 3.

[0029] Example 2.

[0030] The prefilled syringe described in this embodiment has a Luer connector 10 connected to the injection head, and the filter buffer material is a filter buffer plug 5. The filter buffer plug 5 also consists of a mating plug body 7 and a tail flange 8. However, the mating plug body 7 and the tail flange 8 are made of two different materials and are independent components. The filter buffer plug 5 is assembled through a connecting structure.

[0031] like Figure 3 As shown, the tail flange 8 is made of COP / COC material, and the mating plug body 7 is constructed from medical-grade microporous filter material with 0.22 μm pores. The COP / COC tail flange 8 connects to the mating plug body 7 via a socket structure. The gap between the tail flange 8 and the needle tube 1 forms a common air flow channel, allowing external air to enter the mating plug body 7.

[0032] If necessary, a through hole 11 is provided on the tail flange 8 of the COP / COC material to allow the filter holes on the mating plug body 7 to communicate with the outside, thereby achieving its buffering and filtering function. At the same time, if necessary, an annular sealing flange is provided on the outer wall of the mating plug body 7 to achieve a stable connection and sealing effect.

[0033] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0034] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0035] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A prefilled syringe comprising a needle tube, a plunger and an injection head, wherein the injection head is arranged at the front end of the needle tube, the plunger is sealed in the needle tube and forms a space for accommodating the prefilled medicine between the plunger and the injection head, characterized in that A filter buffer is provided between the end of the needle tube and the plunger. The filter buffer is provided with a filter hole. A buffer cavity is formed between the plunger and the filter buffer. The buffer cavity is communicated with the outside through the filter hole.

2. The prefilled syringe according to claim 1, wherein The filtering buffer is a filtering buffer membrane composed of a medical microporous filter material with filtering holes having a pore size of less than or equal to 0.22 μm.

3. The prefilled syringe according to claim 1, wherein The filtering buffer is a filtering buffer plug made of medical microporous filter material with filtering pores smaller than or equal to 0.22 μm.

4. The prefilled syringe according to claim 3, wherein The filter buffer plug is composed of a matching plug body and a tail flange through an integrated forming structure. The matching plug body matches the inner diameter of the needle tube, and the tail flange matches the tail end face of the needle tube.

5. The prefilled syringe according to claim 3, wherein The filter buffer plug is composed of a matching plug body and a tail flange, the matching plug body matches the inner diameter of the needle tube, the tail flange matches the tail end face of the needle tube, and the matching plug body is composed of a medical microporous filter material with a filter hole with a pore size less than or equal to 0.22um.

6. The prefilled syringe according to claim 5, wherein A vent hole is provided on the tail flange, and the matching plug body contacts the external air through the vent hole.

7. The prefilled syringe according to any one of claims 3 to 6, characterized in that The outer wall of the filter buffer plug close to the plunger is provided with a sealing flange, and the sealing flange is annular or spiral.

8. The prefilled syringe according to any one of claims 1 to 6, characterized in that The injection head is provided with an injection needle.

9. The prefilled syringe according to any one of claims 1 to 6, wherein The injection head is provided with a Luer connector.

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