Syringe assembly with separation member

Abstract

Method of expelling a liquid from a needle of a syringe assembly, the method comprising steps of: - providing a syringe, comprising a barrel and a piston which is moveable through the barrel; - connecting a separation member holder to the barrel of the syringe, the separation member holder comprising a first chamber, a second chamber, and an air-permeable liquid impermeable separation member between the first chamber and the second chamber; - drawing in a liquid into the first chamber; - connecting a needle assembly to the separation member holder; and - expelling the liquid from the first chamber through a needle of the needle assembly.

Description

[0001] Title: Syringe assembly with separation member

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to the field of syringe assemblies for intravitreal injections.

[0004] BACKGROUND

[0005] Nowadays, retinal diseases are often treated using liquid medicament which has to be injected into the eye. Such injections are commonly referred to as intravitreal injections.

[0006] Intravitreal injections are performed using syringe assemblies, comprising a syringe with a barrel and a piston, and a needle connected to the barrel. When the barrel is filled with liquid medicament, which liquid medicament is present between the piston and the needle. By forcing the piston towards the needle, the liquid medicament is expelled from the syringe assembly, into the eye.

[0007] SUMMARY

[0008] It is an aim to provide for methods, syringe assemblies and components of syringe assemblies which allow for safer intravitreal injections. In particular, it is an aim to prevent the liquid medicament which is to be injected into the eye from being contaminated. It has been observed that syringe assemblies may be contaminated with undesired compounds, such as lubricants, for example silicone oil. When the liquid medicament contacts these undesired compounds, the undesired compounds may be transported with the liquid medicament into the eye, which in turn may result in undesired medical effects to a patient.

[0009] A first aspect of the present disclosure provides a method of expelling a liquid from a first chamber of a syringe assembly. The method comprises a step of displacing air through an air-permeable liquid- impermeable separation member of the syringe assembly from a second chamber of the syringe assembly to the first chamber, thereby expelling the liquid from the first chamber.

[0010] By using air from a second chamber to expel the liquid from the first chamber, it can be prevented that liquid medicament has to be present in the second chamber. Furthermore, the separation member prevents liquid medicament from flowing into the second chamber. Thereby, when an undesired compound is present in the second chamber, the undesired compound cannot contaminate the liquid medicament, and the undesired compound cannot be transported with the liquid medicament for example into an eye of a patient.

[0011] At least part of the second chamber is typically but not necessarily formed by a barrel of a syringe. Through the barrel, a piston is typically moved for drawing in and expelling fluid from the barrel. To facilitate movement of the piston through the barrel, while maintaining a fluid-tight seal between the piston and the barrel, often a lubricant, such as silicon oil, is used. Such lubricant may form an undesired compound which the present disclosure aims to prevent being transported with the liquid medicament. Displacing air through the separation member is preferably performed by forcing the piston through the barrel of the syringe towards the separation member, in particular by a human operator.

[0012] Within the context of the present disclosure, the separation member being air-permeable implies that air can flow through the separation member, for example when the pressure at a first side of the separation member is lower than the pressure at a second side of the separation member. In general, air can pass through an air-permeable separation member in two opposing directions.

[0013] Any liquid-impermeable separation member is further arranged to prevent a flow of liquid through the separation member, under normal use, at least in one direction through the separation member, preferably in two opposite directions. Normal use relates to typical pressure differences over the separation member, for example caused by a user forcing a piston of a syringe through a barrel.

[0014] Preferably, but not necessarily, in any aspect of the present disclosure, the separation member is a PTFE (Polytetrafluoroethylene) membrane filter. More in general, the separation member preferably is hydrophobic and / or oleophobic, and / or is arranged to prevent passage of silicone oil and / or oleamide and / or any other lubricant, in any combination thereof.

[0015] In general, the liquid referred to in the present disclosure may be a liquid medicament, in particular a liquid eye medicament. In general, the air referred to in the present disclosure is ambient air.

[0016] A second aspect of the present disclosure provides a method of drawing in a liquid into a first chamber of a syringe assembly. The method comprises steps of positioning an opening into the first chamber in liquid communication with the liquid, and displacing air from the first chamber, through an air-permeable separation member of the syringe assembly, to a second chamber of the syringe assembly, thereby lowering a pressure in the first chamber and thus drawing the liquid into the first chamber. The air- permeable separation member is impermeable for the liquid.

[0017] For any method, the air-permeable separation member may be comprised by a separation member holder which is releasable connected to a barrel of a syringe, which syringe is comprised by the syringe assembly. Alternatively, the air-permeable separation member may be comprised by the syringe.

[0018] A third aspect of the present disclosure provides a method of expelling a liquid from a needle of a syringe assembly. The needle may be an intravitreal needle, and the liquid may be a liquid medicament. The method comprises: providing a syringe, comprising a barrel and a piston which is moveable through the barrel; connecting a separation member holder to the barrel of the syringe, the separation member holder comprising a first chamber, a second chamber, and an air-permeable liquid impermeable separation member between the first chamber and the second chamber; drawing in a liquid into the first chamber, in particular using a method according to the second aspect; connecting a needle assembly to the separation member holder; and expelling the liquid from the first chamber through a needle of the needle assembly, in particular using a method according to the first aspect.

[0019] By virtue of the separation member, and by using air to expel the liquid from the first chamber through the needle, it can be prevented that contaminants inside the barrel, in particular between the piston and the separation member, can contact the liquid. The contaminant may be a lubricant used to reduce friction between the piston and the barrel. Use of such a lubricant is preferred to facilitate movement of the piston through the barrel in a smooth manner.

[0020] A fourth aspect provides a separation member holder, which may be used in any method disclosed herein to hold the separation member. The separation member holder comprises: a holder body with a passage through the holder body, which passage extends between a first opening into the holder body and a second opening into the holder body; and an air-permeable liquid impermeable separation member.

[0021] The separation member is positioned in the passage between the first opening and the second opening, and the separation member allows a flow of air through the passage between the first opening and the second opening and prevents a flow of liquid between the first opening and the second opening. The holder body is fluidly connectable to a barrel of a syringe at or near the second opening, and the holder body is fluidly connectable to a needle hub of a needle assembly at or near the first opening.

[0022] A first chamber may be defined between the first opening and the separation member, and / or a second chamber may be defined between the second opening and the separation member. The separation member can prevent liquid from passing from the second chamber to the first chamber, while allowing air to pass between the second chamber and the first chamber.

[0023] Any first chamber may have a volume of at most 0.5 mL, preferably at most 0.1 mL, to allow for small doses typical for intravitreal injections to be accurately dosed. The separation member holder is envisioned with the first liquid at least partially filled with a liquid medicament.

[0024] A fifth aspect provides a kit of parts for forming a syringe assembly. In general, the syringe assembly may be used to perform one or more or all steps of any method according to the first, second, and / or third aspects.

[0025] The kit of parts comprises a syringe having a barrel and a piston moveable in the barrel. Typically, for any syringe disclosed herein, the piston is connected to or formed by a plunger. An end of the plunger extends outside the barrel such that the plunger can be operated. A lubricant can be used between the piston and the barrel to facilitate smooth movement of the piston through the barrel. As such, an inner wall of the barrel can be coated with lubricant.

[0026] The kit of parts further comprises a needle assembly with a needle and a needle hub. The needle may have a sharp tip suitable to pierce an eye. Any needle disclosed herein is preferably a needle for intravitreal injection.

[0027] The kit of parts also comprises an air-permeable liquid impermeable separation member. In the present disclosure, liquid impermeable may imply that the separation member is at least impermeable for lubricant used to facilitate smooth movement of the piston through the barrel. When the separation member is arranged to be positioned to separate a first chamber from a second chamber, the first chamber defined between the needle and a first side of the separation member and the second chamber defined between the piston and a second side of the separation member, the separation member can in use prevent liquid in the first chamber from being contaminated with liquid present in the second chamber, while allowing air from the second chamber to be used to expel liquid from the first chamber.

[0028] Preferably, but not necessarily, the separation member is comprised by a separation member holder. However, it is also envisioned that the separation member is comprised by or at least directly connected to the syringe or the needle assembly. As such, a syringe assembly can be formed with an air-permeable separation member separating a first chamber from a second chamber, the first chamber defined between the needle hub and the separation member and the second chamber defined between the piston and the separation member, without necessarily requiring a separate separation member holder.

[0029] In any kit of parts, the separation member may be comprised by a separation member holder according to the fourth aspect. In such cases, the separation member holder is connectable between the barrel and the needle hub such that, when connected, the separation member is positioned between the barrel and the needle hub.

[0030] A sixth aspect of the present disclosure provides a syringe assembly, comprising: a syringe having a barrel and a piston moveable in the barrel; a needle assembly with a needle and a needle hub; and an air-permeable separation member, wherein the air-permeable separation member separates a first chamber from a second chamber, the first chamber defined between the needle hub and the separation member and the second chamber defined between the piston and the separation member. In use of the assembly, the first chamber may be at least partially filled with a liquid medicament and / or the second chamber may be at least partially filled with air. For example, the first chamber has a volume of at most 0.5 mL, preferably at most 0.1 mL.

[0031] The syringe assembly according to the sixth aspect may be used to perform one or more or all steps in a method according to the third aspect.

[0032] A seventh aspect of the present disclosure provides a method of injecting a liquid medicament into an eye. The method comprising the steps of: inserting a needle comprised by a syringe assembly into the eye; and injecting the liquid medicament into the eye by expelling the liquid medicament from a first chamber of the syringe assembly using a method according to the first aspect and / or by expelling the liquid from the needle of the syringe assembly using a method according to the third aspect.

[0033] It will be appreciated that the syringe assembly may be a syringe assembly according to the sixth aspect. Additionally or alternatively, the liquid medicament may have been drawn into the first chamber of the syringe assembly using a method according to the second aspect.

[0034] BRIEF DESCRIPTION OF THE FIGURES

[0035] In the figures,

[0036] Figs. 1A-1D show consecutive steps in a method of drawing liquid into a first chamber of a syringe and a method of expelling the liquid from the first chamber of a syringe assembly;

[0037] Fig. 2 shows an example of a separation member holder, in a schematic longitudinal section view; and

[0038] Fig. 3 shows another example of a separation member holder, in a schematic longitudinal section view. DETAILED DESCRIPTION OF THE FIGURES

[0039] Figs. 1A-1D show consecutive steps in a method of drawing hquid into a first chamber of a syringe and a method of expelling the hquid from the first chamber of a syringe assembly. In particular, the steps together depict a method of expelling a liquid from a needle of a syringe assembly. By virtue of the methods, contamination of the liquid with any contaminant present in the barrel 302 of the syringe 300 may be prevented. The methods are particular suitable for use in intravitreal injection of hquid medicament, but may also be used in any other medical or non-medical context.

[0040] Figs. 1A-1B schematically show an assembly 100 of a syringe 300 and a separation member holder 200. The syringe 300 comprises a barrel 302 and piston 304 which is moveable through the barrel 302. Typically, the piston 304 forms a gas-tight seal with an inner wall 108 of the barrel 302. Furthermore, typically, a plunger 305 is connected to the piston 304 or integrally formed with the piston 304.

[0041] To facilitate movement of the piston 304 in the barrel 302 in any syringe of the present disclosure, a lubricant can be used, such as silicone oil or oleamide. As such, any liquid present in the barrel 302 may become contaminated with the lubricant. To prevent this contamination, the present disclosure contemplates preventing liquid which is for example to be injected into a human or animal body, in particular an eye, from having to enter the barrel 302. Preferably, in any method of expelling a hquid from a needle of a syringe assembly of the present disclosure, no liquid which is to be expelled contacts the barrel, in particular in inner wall 108 of the barrel.

[0042] The separation member holder 200 depicted in Figs. 1A-1D is shown in more detail in Fig. 2. Fig. 2 shows an example of a separation member holder 200, in a schematic longitudinal section view. The separation member holder 200 comprises a separation member 202, which is air- permeable and liquid-impermeable. In the example shown in Fig. 2, the separation member 202 is an air-permeable and liquid-impermeable PTFE membrane filter. Any other means for preventing passage of liquid may be additionally or alternatively be used for the separation member 202. For example, any separation member 202 may be at least partially coated with or formed by a hydrophobic material.

[0043] The separation member holder 200 further comprises a holder body 201 with a passage 203 through the holder body. The passage 203 extends between the first opening 107 into the holder body 201 and a second opening 109 into the holder body 201. The separation member 202 is positioned in the passage 203 between the first opening 107 and the second opening 109. As such, the separation member allows a flow of air through the passage between the first opening and the second opening and prevents a flow of liquid between the first opening and the second opening.

[0044] At or near the second opening 109, the holder body 201 is connectable to the barrel of a syringe, for example using a rotational or twisting connection such as a luer lock, bayonet, or screw-thread connection, or a fitted connection such as a luer slip. At or near the first opening, the holder body 201 is connectable to a needle hub, for example using a rotational or twisting connection such as a luer lock, bayonet, or screw-thread connection, or a fitted connection such as a luer slip.

[0045] In use of the separation member holder 200, the first chamber 101 can be defined between the first opening 107 and the separation member 202, and / or the second chamber 102 can be defined between the second opening 109 and the separation member 202.

[0046] Alternatively to using a separation member holder 200 which is releasably connectable to a syringe and a needle hub, the present disclosure also contemplates that any separation member 202 is comprised by the syringe, comprised by the needle assembly, directly connected to the syringe, in particular positioned in the barrel, or directly connected to the needle hub, in particular positioned inside a skirt of the needle hub. However, using a separate separation member holder 200 to provide for the separation member 202 may be advantageous in terms of manufacturability, and / or the fact that conventional syringes and / or needle assemblies may be used.

[0047] In the example of Fig. 2, the holder body 201 comprises as an option a first holder body part 201’ and a second holder body part 201”. The first holder body part 201’ and the second holder body part 201” may be releasably connected, or may be connected such that the connection can only be irreversibly broken. Additionally or alternatively, the first holder body part 201’ and the second holder body part 201” may be connected with an interference fit, threaded connection, bayonet connection, by adherence, using a clamped connection, and / or in any other way of connecting two body parts.

[0048] As an option depicted in Fig. 2, the separation member 202 can be held between the first holder body part 201’ and the second holder body part 201”, or the separation member 202 is at least partially positioned between the first holder body part 201’ and the second holder body part 201”. The separation member 202 may be in direct contact with at least one of the first holder body part 201’ and the second holder body part 201”. It is also contemplated that the separation member 202 is in contact with the first holder body part 201’ and / or the second holder body part 201” via one or more further components, for example when the separation member 202 is held in a frame or other support structure. In such cases, the frame or other support structure can be held between the first holder body part 201’ and the second holder body part 201”. In particular, the separation member 202 or optional frame or other support structure can be held between one or more end faces, flanges, and / or shoulders of the first holder body part 201’ and the second holder body part 201”.

[0049] To form a separation member holder 200, a separation member 202 may be positioned between the first holder body part 201’ and the second holder body part 201”, and the first holder body part 201’ and the second holder body part 201” can subsequently be connected, for example with an interference fit. In the example of Fig. 2, the first opening 107 is provided by the first holder body part 201’, and the second opening 109 is provided by the second holder body part 201”. In use, the first chamber 101 can be provided by the first holder body part 201’, and / or the second chamber 102 can be provided by the second holder body part 201”.

[0050] The first holder body part 201’ is connectable to a syringe, in particular to a barrel of a syringe, for example via an interference fit connection and / or a threaded connection. The second holder body part 201” is connectable to a needle hub, for example via an interference fit connection and / or a threaded connection.

[0051] Now referring back to the syringe assembly 100 of Figs. 1A-1B. In the syringe assembly 100 of Figs. 1A-1D, the separation member 200 is connected to the barrel 302 of the syringe 300, preferably in a releasable manner. In the assembly 100, the barrel 302 of the syringe is in particular connected to the holder body 201. As an option, the barrel 302, in particular an end face of the barrel 302, contacts the separation member 202. The connection between the barrel 302 and the separation member holder 200 is preferably air-tight, such that an air-tight second chamber 102 can be formed between the barrel 302, piston 304, and the separation member 202. The second chamber 102 is defined between the separation member 202, an inner wall 108 of part of the barrel 302, and the piston 304.

[0052] Between the situations depicted in Figs. 1A and IB, liquid 104 has been drawn into a first chamber 101 of the syringe assembly 100. The first chamber 101 is here defined between the first opening 107, the separation member 202, and part of the holder body 201. To draw liquid 104 into the first chamber 101, for example, the opening 107 can be positioned in liquid communication with a source of the liquid 104, for example a vial or other container. By subsequently moving the piston 304 through the barrel 302, in particular in a direction away from the separation member 202, air 106 can be drawn from the first chamber 101 into the second chamber 102. In this process, air 106 is thus displaced through the air-permeable separation member 202, and a pressure in the first chamber 101 is lowered to draw the liquid 104 into the first chamber 101. The volume of liquid 104 now present in the first chamber 101 may be essentially equal to or lower than the volume of liquid 104 which is to be expelled from the needle in a subsequent method step. Preferably, but not necessarily, essentially the entire first chamber 101 is filled with the liquid 104.

[0053] When moving the piston 304 through the barrel 302, part of an inner wall 108 of the barrel 302 may become contaminated with lubricant. It is an object of the present disclosure to prevent lubricant from contacting the liquid 104 to be expelled.

[0054] Between the situations depicted in Figs. IB and 1C, a needle assembly 400 is connected to separation member holder 200, in particular at or near the first opening 107. The needle assembly 400 comprises a needle hub 404 and a needle 402 connected to the needle hub 404. Typically, the needle hub 404 is connected to the holder body 201, for example using a threaded connection such as a luer lock, or a slip-fit connection such as a luer slip. The needle 402 is typically a needle for intravitreal injection, any other needle for medical use, or any needle for non-medical use.

[0055] Preferably, the needle hub 404 contacts the liquid 104 in the assembly state of the syringe assembly of Fig. 1C. As such, it can be prevented that air becomes trapped between the liquid 104 and the needle hub 404, which air may become ejected together with the liquid 104.

[0056] Between the situations depicted in Figs. 1C and ID, the liquid 104 inside the first chamber 101 has been expelled from the first chamber 101, through the needle 402. In particular, the liquid 104 has been expelled by displacing air 106 from the second chamber 102 through the separation member 202 into the first chamber 101. The air 106 is forced out of the second chamber 102 by moving the piston 304 through the barrel 302, in particular in a direction towards the separation member 202. The separation member 202 by being impermeable for liquid prevents any lubricant or other contaminant potentially present in the second chamber 102 from transitioning into the first chamber 101. After expelling the liquid 104 from the first chamber 101, the volume of air left in the second chamber may be essentially zero.

[0057] Fig. 3 shows another example of a separation member holder 200, with similar reference numerals indicating similar elements as disclosed in conjunction with Fig. 2. As applicable for any separation member 202, in Fig. 3, the separation member 202 is depicted as comprising a number of passages 210. By virtue of one or more passages 210 through the separation member 202, which passages 210 have a pore size of at most 10 pm, at most 5 pm, or even at most 1 pm. The small pore size of the one or more passages 210 combined with the surface tension of liquid prevents liquid from passing through the separation member 202 in normal use. Passages and sections thereof may be oriented in any direction, for example essentially parallel to a centreline 205 of the holder body 201, or at any angle relative to the centreline.

[0058] In general, the present disclosure contemplates that the holder body 201 can be formed by a single body, or by any number of optionally releasable interconnected bodies. It will be understood that the two examples of the separation member holder depicted in Figs. 2 and 3 represent only a limited number of examples envisioned in the present disclosure. Options disclosed in conjunction with any particular separation member holder are readily applicable to any other separation member holder.

Claims

Claims1. Method of expelling a liquid (104) from a first chamber (101) of a syringe assembly (100), the method comprising a step of: displacing air (106) through an air-permeable liquid-impermeable separation member (202) of the syringe assembly from a second chamber (102) of the syringe assembly to the first chamber, thereby expelling the liquid from the first chamber.

2. Method according to claim 1, wherein at least part of the second chamber is formed by a barrel (302) of a syringe (300) of the syringe assembly.

3. Method according to any of the preceding claims, wherein the liquid is a liquid medicament.

4. Method of drawing in a liquid into a first chamber (101) of a syringe assembly, the method comprising the steps of: positioning an opening (107) into the first chamber in liquid communication with the liquid; and displacing air from the first chamber, through an air-permeable separation member of the syringe assembly, to a second chamber of the syringe assembly, thereby lowering a pressure in the first chamber and thus drawing the liquid into the first chamber; wherein the air-permeable separation member is impermeable for the liquid.

5. Method according to claim 4, wherein the liquid is a liquid medicament.

6. Method according to any of the preceding claims, wherein the air- permeable separation member is comprised by a separation member holderwhich is releasable connected to a barrel of a syringe, which syringe is comprised by the syringe assembly.

7. Method of expelling a liquid from a needle of a syringe assembly, the method comprising steps of: providing a syringe, comprising a barrel and a piston which is moveable through the barrel; connecting a separation member holder to the barrel of the syringe, the separation member holder comprising a first chamber, a second chamber, and an air-permeable liquid impermeable separation member (202) between the first chamber and the second chamber; drawing in a liquid into the first chamber using a method according to any of the claims 4-6; connecting a needle assembly to the separation member holder; and expelling the liquid from the first chamber through a needle of the needle assembly using a method according to any of the claims 1-3.

8. Method according to claim 7, wherein a lubricant is used to reduce friction between the piston and the barrel.

9. Separation member holder (200), comprising: a holder body (201) with a passage (203) through the holder body, which passage extends between a first opening (107) into the holder body and a second opening (109) into the holder body; and an air-permeable liquid impermeable separation member (202); wherein the separation member is positioned in the passage between the first opening and the second opening, and the separation member allows a flow of air through the passage between the first opening and the second opening and prevents a flow of liquid between the first opening and the second opening; andwherein the holder body is fluidly connectable to a barrel of a syringe at or near the second opening, and the holder body is fluidly connectable to a needle hub of a needle assembly at or near the first opening.

10. Separation member holder according to claim 9, wherein a first chamber is defined between the first opening and the separation member, and a second chamber is defined between the second opening and the separation member.

11. Separation member holder according to claim 9 or 10, wherein the first chamber has a volume of at most 0.5 mL, preferably at most 0.1 mL.

12. Separation member holder according any of the claims 9-11, wherein the first chamber is at least partly filled with a liquid medicament.

13. Separation member according to any of the claims 9-12, wherein the separation member is or comprises a PTFE membrane filter.

14. A kit of parts for forming a syringe assembly (100), the kit of parts comprising: a syringe (300) having a barrel (302) and a piston (304) moveable in the barrel; a needle assembly (400) with a needle (402) and a needle hub (404); and an air-permeable liquid impermeable separation member (202), wherein the separation member is arranged to be positioned to separate a first chamber from a second chamber, the first chamber defined between the needle and a first side of the separation member and the second chamber defined between the piston and a second side of the separation member.

15. Kit of parts according to claim 14, wherein the separation member is comprised by a separation member holder according to any of the claims 9- 13, which separation member holder is connectable between the barrel and the needle hub such that, when connected, the separation member is positioned between the barrel and the needle hub.

16. A syringe assembly, comprising: a syringe having a barrel and a piston moveable in the barrel; a needle assembly with a needle and a needle hub; and an air-permeable liquid-impermeable separation member, wherein the air-permeable separation member separates a first chamber from a second chamber, the first chamber defined between the needle hub and the separation member and the second chamber defined between the piston and the separation member.

17. The syringe assembly according to claim 16, wherein the first chamber is at least partially filled with a liquid medicament.

18. The syringe assembly according to claim 16 or 17, wherein the second chamber is at least partially filled with air.

19. The syringe assembly according to any of the claims 16- 18, wherein the first chamber has a volume of at most 0.5 mL, preferably at most 0.1 mL.

20. Method of injecting a liquid medicament into an eye, the method comprising the steps of: inserting a needle comprised by a syringe assembly into the eye; and injecting the liquid medicament into the eye by expelling the liquid medicament from a first chamber of the syringe assembly using a method according to any of the claims 1-3

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