Double-cavity pre-filled syringe

Abstract

The utility model provides a double-cavity prefilled syringe which comprises a needle cylinder, an outer piston, a piston rod and a finger support, the outer piston is fixedly arranged at the upper end of the piston rod, the finger support is fixedly arranged at the lower end of the piston rod, a convex runner is arranged on the side wall of the needle cylinder, an inner piston is arranged in the needle cylinder, and an inner cavity of the needle cylinder is divided into a front cavity and a rear cavity by the inner piston. The length of the inner piston is smaller than that of the convex runner; a sleeve with a C-shaped cross section is arranged at the bottom of the needle cylinder and arranged on the outer side of the piston rod in a sleeving mode, and the distance between the inner piston and the outwards-protruding flow channel is equal to the distance between the finger support and the sleeve. The syringe has the advantages that the inner piston arranged in the needle cylinder divides the cavity into the front cavity and the rear cavity, so that the inner piston can be accurately matched with the outwards-protruding flow channel when moving. The sleeve arranged at the bottom of the needle cylinder further limits the propelling range of the piston rod, it is guaranteed that the piston rod cannot be excessively propelled, and sufficient time and space are provided for mixing of liquid medicine.

Description

TECHNICAL FIELD

[0001] The utility model relates to syringe technical field, concretely relates to a double cavity pre-filled syringe. BACKGROUND

[0002] The pre-filled syringe is an innovative medical device integrating medicine storage and injection functions, which is widely used in medical, biological pharmaceutical and other fields. The core component is an outer sleeve body made of pharmaceutical grade glass. This material has excellent chemical stability and biocompatibility, which can effectively prevent reaction with drugs and ensure the long-term stability of liquid medicine during storage. At the same time, the high transparency of glass material facilitates medical staff to observe the properties and dosage of the liquid medicine, further improving the safety and convenience of use.

[0003] At present, the pre-filled syringe on the market generally adopts single chamber design, which is only suitable for packaging single drug. However, with the progress of modern medical technology, the demand for new formulations such as compound preparations, powder injections and freeze-dried powder injections that need to be used in combination is increasing. This development trend makes the limitations of traditional single chamber pre-filled syringe in clinical application increasingly prominent, which has been difficult to meet the needs of diversified drug therapy. Therefore, developing a new pre-filled syringe system with multi-chamber structure and realizing instant mixing of drugs has become an important research direction in the field of medical devices. The current double cavity syringe makes a protrusion in the middle of the glass tube. During the pushing process, the liquid medicine is mixed with the front medicine and powder through the channel, and the proportioning is completed.

[0004] However, there are some deficiencies:

[0005] When the internal piston moves forward under the action of the rear liquid force, there is no obvious blocking piece, which is easy to continue to move forward and block the liquid mixing channel, resulting in uneven mixing of the liquid, causing waste and being unable to control the liquid proportioning. UTILITY MODEL CONTENTS

[0006] The utility model discloses to the internal piston is not easy to position, resulting in uneven mixing of the liquid, causing waste and being unable to control the liquid proportioning.

[0007] The utility model provides a double cavity pre-filled syringe, including needle cylinder, outer piston, piston rod and finger support, the outer piston is fixedly arranged on the upper end of piston rod, and the finger support is fixedly arranged on the lower end, the lateral wall of needle cylinder is provided with outer convex flow channel, and the inside of needle cylinder is provided with inner piston, and the inner piston divides the inside chamber of needle cylinder into front chamber and rear chamber, and the length of inner piston is less than the length of outer convex flow channel.

[0008] As a preferred embodiment, the front chamber contains powder or lyophilized powder, and the rear chamber contains liquid medicine or diluent solution.

[0009] As a preferred embodiment, the syringe is provided with a protective cap at the top.

[0010] As a preferred embodiment, the cap and the top of the syringe are provided with a threaded connection.

[0011] As a preferred embodiment, the top end of the sleeve is provided with a protrusion for use with the bottom end of the syringe.

[0012] As a preferred embodiment, the sleeve is made of an elastic material, and the maximum width of the sleeve after deformation is not less than the diameter of the piston rod.

[0013] The beneficial effects of this utility model are as follows:

[0014] This invention features an internal piston that divides the syringe into a front and rear chamber. The length of the internal piston is shorter than the length of the external flow channel, allowing for a precise fit between the internal piston and the external flow channel during movement. When the piston rod advances, the movement of the internal piston is restricted by the external flow channel, preventing excessive forward movement and blockage of the front chamber, thus ensuring sufficient flow of the medication between the rear and front chambers. Furthermore, a sleeve at the bottom of the syringe further restricts the piston rod's advance range, preventing over-advancement and providing ample time and space for medication mixing. This not only improves the mixing efficiency but also avoids waste caused by incomplete mixing, making it particularly suitable for scenarios requiring precise control of the medication mixing ratio. Attached Figure Description

[0015] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0018] The numbers in the attached diagram are:

[0019] 1. Syringe; 11. Front chamber; 12. Rear chamber; 2. Outer piston; 3. Piston rod; 4. Finger support; 5. Outer protruding flow channel; 6. Inner piston; 7. Sleeve; 71. Protrusion; 72. Opening; 8. Protective cap. Detailed Implementation

[0020] To illustrate the features of this utility model, the following description, in conjunction with embodiments, will further explain this utility model.

[0021] Example:

[0022] Please see Figure 1 and Figure 2 This utility model provides a dual-chamber pre-filled syringe, including a syringe barrel 1, an outer piston 2, a piston rod 3, and a finger support 4. The outer piston 2 is fixedly installed at the upper end of the piston rod 3, and the finger support 4 is fixedly installed at the lower end. The side wall of the syringe barrel 1 is provided with an outwardly protruding flow channel 5. An inner piston 6 is provided inside the syringe barrel 1. The inner piston 6 divides the internal chamber of the syringe barrel 1 into a front chamber 11 and a rear chamber 12. The length of the inner piston 6 is less than the length of the outwardly protruding flow channel 5. A sleeve 7 with a C-shaped cross-section is provided at the bottom of the syringe barrel 1 and is sleeved on the outside of the piston rod 3. The distance between the inner piston 6 and the outwardly protruding flow channel 5 is equal to the distance between the finger support 4 and the sleeve 7.

[0023] Preferably, in this embodiment, the front chamber 11 contains powder and the rear chamber 12 contains liquid medicine.

[0024] Preferably, in this embodiment, a protective cap 8 is provided on the top of the syringe 1.

[0025] Preferably, in this embodiment, the cap 8 and the top of the syringe 1 are connected by a threaded connection.

[0026] Preferably, in this embodiment, the top end of the sleeve 7 is provided with a protrusion 71 for use with the bottom end of the syringe 1.

[0027] Preferably, in this embodiment, the sleeve 7 is made of rubber, and the maximum width of the opening 72 of the sleeve 7 after deformation is not less than the diameter of the piston rod 3.

[0028] How to use this embodiment:

[0029] The glass vial is divided into a front chamber and a rear chamber by an inner piston. The front chamber contains powder, and the rear chamber contains liquid medication. Pushing the piston rod causes the inner piston to slide forward through the liquid medication in the rear chamber. When the piston rod is stopped by a retaining clip, the inner piston is positioned in the middle of the convex flow channel. The front and rear chambers are connected by a groove, allowing the liquid medication in the rear chamber to flow into the front chamber through the convex flow channel. Manually shake the syringe to mix the medication thoroughly. Then remove the retaining clip to continue pushing the piston rod for injection.

[0030] The above embodiments and accompanying drawings are only used to illustrate the technical solutions of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model. Other related technical structures not disclosed in detail in this utility model are existing technologies in the art.

Claims

1. A double chamber pre-filled syringe, comprising a barrel (1), an outer piston (2), a piston rod (3) and a finger rest (4), the outer piston (2) is fixedly arranged on the upper end of the piston rod (3), and the finger rest (4) is fixedly arranged on the lower end of the piston rod (3), characterized in that: The side wall of the barrel (1) is provided with an outer convex flow channel (5), and the barrel (1) is internally provided with an inner piston (6), the inner piston (6) divides the inner chamber of the barrel (1) into a front chamber (11) and a rear chamber (12), and the length of the inner piston (6) is less than the length of the outer convex flow channel (5); The bottom of the barrel (1) is provided with a sleeve (7) with a C-shaped cross section, which is sleeved outside the piston rod (3), and the distance between the inner piston (6) and the outer convex flow channel (5) is equal to the distance between the finger rest (4) and the sleeve (7).

2. The dual chamber pre-filled syringe of claim 1, wherein: The front chamber (11) is provided with a powder or a lyophilized powder, and the rear chamber (12) is provided with a liquid drug or a dilution solution.

3. The dual chamber pre-filled syringe of claim 1, wherein: The top of the barrel (1) is provided with a cap (8).

4. The dual chamber pre-filled syringe of claim 3, wherein: The cap (8) and the top of the barrel (1) are provided with threaded connection.

5. The dual chamber pre-filled syringe of claim 1, wherein: The top end of the sleeve (7) is provided with a protruding part (71) for cooperating with the bottom end of the barrel (1).

6. The dual chamber pre-filled syringe of claim 1, wherein: The sleeve (7) is made of elastic material, and the maximum width of the opening (72) of the sleeve (7) after deformation is not less than the diameter of the piston rod (3).

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