Finger grip for syringe assembly, method for manufacturing finger grip, syringe assembly, kit and use of syringe assembly

Abstract

FIELD: medicine; medical equipment.SUBSTANCE: finger grip for a syringe unit for introducing a liquid composition, a method for manufacturing it, a syringe unit for introducing a liquid composition into the body of a person or animal, containing said grip, a kit for introducing a liquid composition into the body of a person or animal, containing parts of said syringe unit, and the use of said syringe unit in the field of cosmetic or therapeutic application. The finger grip (30) comprises a housing (30) with two flanges (31, 32) extending radially in opposite directions from a central channel (37) in the housing, through which a plunger (20) of the syringe assembly can be inserted. Each flange (31, 32) functions as a gripping portion and has a finger contact area on which at least one user's finger can be partially placed during insertion to provide support to said finger during insertion. Each flange (31, 32) comprises a distally facing surface (33) and a proximally facing surface (34). The finger grip (30) comprises a gripping pad (35) attached to the distally facing surface (33) of at least one of the flanges (31, 32) and extending at least partially over said distally facing surface (33). The grip plate (35) is made by injection moulding. The overlay (35) for gripping on the distally facing surface (33) of the corresponding flange or wing (31, 32) is made in one piece and contains only one injection point (26). The gripping pad (35) is designed in such a way that at least one area (36) not filled or covered with the gripping pad material is completely surrounded by the injection molding material, and wherein the area (36) not filled or covered with the gripping pad material contains one or more stripes or displays the “+” symbol. The method for manufacturing the above-described finger grip (30) includes at least the steps of: manufacturing the body (30) of the finger grip, and forming the grip pad (35) by injection molding. A syringe unit (100, 200) for introducing a liquid composition into the body of a human or animal, comprising at least: a longitudinal cylinder (10) of the syringe, having an internal cavity (13) for receiving and storing the liquid composition to be introduced, the above-described finger grip (30), connected to the proximal end of said cylinder (10), and a plunger (20), having a plunger rod (21) and a plunger head (22), wherein the plunger rod (21) is located at least partially inside the internal cavity (13) of the cylinder (10) with its distal end (25). A kit for introducing a liquid composition into the body of a human or animal comprises parts of the previously mentioned syringe assembly (100, 200), wherein the parts of the kit are designed with the possibility of assembly to obtain the previously mentioned syringe assembly (100, 200).EFFECT: use of the above-described syringe assembly (100, 200) in the field of cosmetic or therapeutic use, wherein an effective volume of a liquid composition is administered to a patient.9 cl, 21 dwg

Description

[0001] Technical field

[0002] The present invention relates to a plunger for a syringe assembly for administering a liquid composition and to a method for manufacturing such a plunger, wherein the plunger comprises a plunger rod and a plunger head, wherein the plunger rod comprises a proximal end and a distal end, and the plunger head is attached to the proximal end of the plunger rod and comprises a proximally facing surface configured to perform the function of a thumb plate during administration.

[0003] Furthermore, the present invention relates to a finger grip for a syringe assembly for administering a liquid composition and to a method for manufacturing such a finger grip, wherein the finger grip comprises a finger grip body with two flanges extending radially in opposite directions from a central channel in the finger grip body through which a plunger of the syringe assembly can be inserted, wherein each flange functions as a part of the grip and has a finger contact area on which at least one finger of the user can be partially placed during administration to provide support to said finger during administration, and wherein each flange comprises a proximally facing surface and a distally facing surface.

[0004] Furthermore, the present invention relates to a syringe assembly for introducing a liquid composition into the body of a human or animal, at least comprising a longitudinal syringe barrel having an internal cavity for receiving and storing a liquid composition to be introduced, a finger grip connected to the proximal end of said barrel, and a plunger having a plunger rod and a plunger head, wherein the plunger rod is located at least partially inside the internal cavity of the barrel with its distal end.

[0005] Furthermore, the present invention relates to a kit containing parts of the said syringe assembly.

[0006] Furthermore, the present invention relates to the use of the above-described syringe assembly or the above-described kit in the field of cosmetic or therapeutic use, in particular for replacing or filling biological tissue or increasing the volume of biological tissue.

[0007] Technology Level

[0008] Syringe assemblies for administering a liquid composition and kits comprising several parts for assembling a syringe, in particular comprising at least a syringe barrel, a finger grip and a plunger having a plunger rod and a plunger head, are known in the art for applications in a wide range of fields.

[0009] A prior art discloses an injection device, for example, comprising a syringe barrel having a housing with an open-ended piston located therein, which can be pre-filled with a viscous fluid. A needle assembly is provided, including a cannula having a locking connection adapted to engage with the distal end of a syringe with a Luer Lock connector including a sleeve. Mating engagement is ensured by internal threads on the distal end of the syringe and external threads of said sleeve with a pitch sufficient to prevent the sleeve from detaching from the distal end of the syringe when the viscous fluid is ejected from the syringe barrel. Furthermore, a specially designed sleeve also prevents the sleeve from detaching from the distal end of the syringe when the viscous fluid is ejected.

[0010] Furthermore, a syringe assembly for delivering a fluid is known, in which the syringe assembly comprises pusher means and a disposable cartridge configured to contain the fluid to be delivered, wherein the disposable cartridge comprises a container defining a chamber for the fluid, and sheath means configured to hermetically isolate the chamber from the environment.

[0011] Furthermore, the prior art discloses a syringe assembly for delivering a fluid, in which the syringe assembly comprises a pusher means and a disposable cartridge configured to contain a fluid to be delivered, wherein the disposable cartridge comprises a container defining a chamber for the fluid and provided with a threaded flange to which the fluid delivery means can be detachably screwed.

[0012] Furthermore, an aspiration and injection device is known that can provide cost-effective, safe, and accurate aspiration from a target site and delivery of a drug to the target site. The device may include a syringe barrel, a flanged extension connected to the barrel, and a plunger that can be activated by the user's hand and / or one or more fingers to perform aspiration and injection at the target site.

[0013] Furthermore, it is known to use a tip cap to close and / or seal the distal end of a syringe barrel.

[0014] Furthermore, methods for manufacturing syringe assemblies and kits as described above, as well as methods for manufacturing individual components for syringe assemblies or kits, are generally known. In particular, methods for manufacturing syringe barrels, plungers, and / or finger grips are known from the prior art.

[0015] Furthermore, the prior art discloses a method for manufacturing a syringe barrel, comprising an injection step for applying an inert silicone oil to the inner surface of the barrel by spraying the silicone oil thereon, and a heating step for heating the applied silicone oil to reduce its viscosity. The inner surface of the syringe barrel is coated with an inert silicone oil having a viscosity of 3,000 to 30,000 cP. The silicone oil coating ratio is no more than 20%.

[0016] Problems of the invention

[0017] In view of the above, one of the objects of the present invention is to provide an alternative plunger, in particular an improved plunger, for a syringe assembly for administering a liquid composition. Another object is to provide a method for manufacturing a plunger for a syringe assembly, to provide an alternative finger grip for a syringe assembly, in particular an improved finger grip, to provide a method for manufacturing a finger grip, an alternative syringe assembly, in particular an improved syringe assembly, an alternative kit containing parts of a syringe assembly, in particular an improved kit, and an alternative, in particular an improved, method for using a syringe assembly or kit.

[0018] Disclosure of the essence of the invention

[0019] The objects of the present invention are a plunger for a syringe assembly, a method for manufacturing such a plunger, a finger grip for a syringe assembly, a method for manufacturing such a finger grip, a syringe assembly, a kit containing parts of a syringe assembly, and a method for using a syringe assembly or kit, each of which is defined according to the corresponding independent claim of the invention.

[0020] The first aspect of the present invention relates to a plunger for a syringe assembly for administering a liquid composition, wherein the plunger comprises a plunger shaft and a plunger head. The plunger shaft comprises a proximal end and a distal end, wherein the plunger head is attached to the proximal end of the plunger shaft. The plunger head comprises a proximally facing surface configured to function as a thumb plate during insertion. According to the present invention, the plunger comprises a gripping pad attached to the proximally facing surface of the plunger head, wherein the gripping pad extends at least partially over said proximally facing surface and is formed by injection molding.

[0021] A second aspect of the present invention relates to a method for manufacturing the plunger described above, wherein the method comprises at least the steps of:

[0022] - manufacturing, in particular, at least the plunger head and

[0023] - forming the grip lining by injection molding.

[0024] The third aspect of the present invention relates to a finger grip for a syringe assembly for administering a liquid composition, wherein the finger grip comprises a finger grip body with two flanges extending radially in opposite directions from a central channel of the finger grip body, wherein a plunger of the syringe assembly can be inserted through the central channel. Each flange functions as a part of the grip and has a finger contact area on which at least one user's finger can be partially placed during insertion to provide support for said finger during insertion. Furthermore, each flange comprises a proximally facing surface and a distally facing surface.According to the present invention, the finger grip comprises a gripping pad attached to the distally facing surface of at least one of the flanges, wherein the gripping pad extends at least partially over said distally facing surface and is made by injection molding.

[0025] A fourth aspect of the present invention relates to a method for manufacturing the previously described finger grip, wherein the method comprises at least the steps of:

[0026] - manufacturing a finger grip body that includes two flanges extending radially in opposite directions from a central channel in the finger grip body, wherein a plunger of a syringe assembly can be inserted through said central channel, wherein each flange functions as a part of the grip and has a finger contact area on which at least one finger of the user can be partially placed during insertion to provide support to said finger during insertion, wherein each flange comprises a proximally facing surface and a distally facing surface, and

[0027] - forming the grip lining by injection molding.

[0028] The fifth aspect of the present invention relates to a syringe assembly for administering a liquid composition into the body of a human or an animal, at least comprising a longitudinal syringe barrel having an internal cavity for receiving and storing a liquid composition to be administered, a finger grip connected to the proximal end of said barrel, and a plunger having a plunger shaft and a plunger head, wherein the plunger shaft is located at least partially inside the internal cavity of the barrel with its distal end. According to the present invention, the plunger is a plunger according to the present invention or a plunger manufactured by the method according to the present invention, and / or the finger grip is a finger grip according to the present invention or a finger grip manufactured by the method according to the present invention.

[0029] The sixth aspect of the present invention relates to a kit comprising several parts of a syringe assembly according to the present invention, wherein the parts are configured to be assembled to form a similar syringe assembly. The kit comprises a longitudinal syringe barrel having an internal cavity for receiving a liquid composition to be administered, a finger grip configured to be connected to the proximal end of said barrel, and a plunger having a plunger shaft and a plunger head, wherein the plunger shaft is configured to be positioned at least partially within the internal cavity of the barrel with its distal end. According to the present invention, the plunger is a plunger according to the present invention or a plunger manufactured by the method according to the present invention, and / or the finger grip is a finger grip according to the present invention or a finger grip manufactured by the method according to the present invention.

[0030] The seventh aspect of the present invention relates to the use of a syringe assembly according to the present invention or a kit according to the present invention in the field of cosmetic or therapeutic use, in particular for replacing or filling biological tissue or increasing the volume of biological tissue, wherein an effective volume of a liquid composition, in particular an effective volume of a dermal filler composition, is administered to a patient.

[0031] The present invention makes it possible to provide a very light, convenient and safe to use syringe assembly for administering a liquid composition, in particular for administering a dermal filler, in particular for administering a dermal filler based on hyaluronic acid, and accordingly, a very light, convenient and safe to use kit containing parts of a syringe assembly, wherein the syringe assembly and / or kit, and accordingly, the individual parts of said kit and / or syringe assembly are easy to manufacture and allow for convenient storage and easy handling by a practitioner.

[0032] By providing a gripping pad attached to the proximally facing surface of the plunger head and / or a gripping pad attached to the distally facing surface of one of the flanges of the finger gripper body, a plunger with a plunger head with a comfortable and less slippery finger contact area can be provided, and accordingly, a finger grip with a comfortable and less slippery finger contact area can be provided. Thus, a more comfortable, precise, and safer-to-use syringe assembly or kit can be provided. Reducing finger slippage leads to more controlled use, in particular when administering highly viscous fluids, such as when injecting or administering a dermal filler, in particular a hyaluronic acid-based dermal filler that requires increased extrusion force.

[0033] Possible and, in particular, preferred embodiments of the present invention are disclosed in the dependent claims. Additional embodiments and other objects, advantages and features of the present invention are apparent from the following detailed description in the section "Carrying Out the Invention," the illustrations of specific embodiments in the accompanying drawings and the detailed description of the embodiments. The wording of the original claims is incorporated into the description by direct reference.

[0034] Implementation of the invention

[0035] A plunger for a syringe assembly for administering a liquid composition according to the first aspect of the present invention comprises a plunger rod and a plunger head, wherein the plunger rod comprises a proximal end and a distal end, and the plunger head is attached to the proximal end of the plunger rod and comprises a proximally facing surface configured to perform the function of a thumb plate during insertion. According to the present invention, the plunger also comprises a gripping pad attached to the proximally facing surface of the plunger head, wherein the gripping pad extends at least partially over said proximally facing surface and is formed by injection molding.

[0036] A grip pad attached to the proximal surface of the plunger head provides a comfortable and less slippery finger contact area for the plunger head. This makes the plunger-containing syringe assembly more convenient, precise, and safe to use. The reduced risk of finger slippage achieved by the grip pad significantly improves safety during use, particularly during injection. The grip pad provides an improved grip, resulting in more controlled use, particularly when using the plunger in a syringe assembly for administering highly viscous fluids, such as when injecting or administering dermal fillers, particularly hyaluronic acid-based dermal fillers that require increased extrusion force.Using injection molding to produce the plunger head grip liner provides a very easy and cost effective way to produce the grip liner.

[0037] The term "syringe assembly" as used herein generally refers to an application device, in particular an injection device, configured to release, preferably to administer, in particular to inject, at least one component housed and stored in said device. The term "syringe assembly" particularly encompasses application devices, in particular injection devices for dispensing single-, dual-, or multi-component contents, in particular devices for dispensing single-, dual-, or multi-component materials. The term "syringe assembly" as used herein particularly refers to a syringe or syringe-like application device configured to dispense or administer at least one component stored in said device.The term "syringe assembly" as used herein refers in particular to a device operating as a manually operated piston pump, typically comprising a syringe barrel having an internal cavity or chamber for receiving and storing at least one component to be administered, and a plunger, wherein the plunger in particular can be retracted and pushed along the interior of the internal cavity or chamber along the longitudinal axis of the internal cavity, which allows for drawing up and pushing out, in particular, a fluid through an outlet at the proximal end of the internal cavity or chamber, respectively, at the proximal end of the syringe barrel.

[0038] In the context of using the syringe assembly and / or kit according to the present invention, the term "injection" may refer to an intra-, inter- or subdermal injection or a subcutaneous injection.

[0039] The term "composition" as used herein is not particularly limited and may refer, for example, to a liquid composition. Preferably, the composition may be a composition used or suitable for use as a soft tissue filler, in particular a dermal filler.

[0040] The term "liquid composition" in this document shall be taken to cover a liquid (e.g., an aqueous liquid), a solution (e.g., an aqueous solution), a suspension (e.g., an aqueous suspension), a dispersion (e.g., an aqueous dispersion), an emulsion (e.g., an aqueous emulsion), a gel (e.g., a hydrogel), etc., as well as mixtures thereof.

[0041] The term "multi-component content" as used herein refers to a content or composition containing at least two (different) components, in particular more than two (different) components, which must be mixed to ensure a uniform mixture before administration. Accordingly, a single-component composition is a ready-to-use composition, and a two-component composition is a composition containing two components that must be mixed with each other before administration.

[0042] The term "plunger" as used herein refers to a single-piece part or a multi-piece assembly adapted to be used in a syringe assembly to apply a displacement force to contents, such as a liquid composition, housed and stored within an internal cavity or chamber of a syringe barrel, wherein the contents can be forced out of the internal cavity of the syringe barrel by means of the plunger when a sufficient displacement force is applied in the longitudinal direction resulting in longitudinal movement of the plunger within the internal cavity of the syringe barrel along the longitudinal axis of the syringe barrel.

[0043] The term "plunger rod" or "push rod" as used herein refers in particular to a longitudinal, preferably rod-shaped, part adapted to be at least partially inserted with its distal end into an internal cavity or chamber of a syringe barrel.

[0044] The term "plunger head" as used herein refers to a component attached to the proximal end of the plunger shaft that serves as a thumb rest during insertion. For this purpose, the plunger head in particular comprises a substantially flat, proximally facing surface, preferably configured to provide support for the physician's thumb during use, in particular when applying the expulsion force required to dispense the contents housed and stored within the internal cavity or chamber of the syringe barrel.

[0045] In a possible, particularly preferred embodiment of the plunger of the present invention, the head of the plunger may comprise or may be a part made substantially in the form of a plate or a substantially flat disk.

[0046] In a possible, particularly preferred embodiment of the plunger according to the present invention, the head of the plunger can be made integral with the plunger rod, in particular also by injection molding.

[0047] In an alternative embodiment of the plunger of the present invention, the head of the plunger may be connected to the plunger rod, for example, by means of a snap-in connection, in particular a releasable snap-in connection or other mounting mechanism.

[0048] In a possible, particularly preferred embodiment of the plunger of the present invention, the plunger may be configured to be used in a syringe assembly comprising a syringe barrel configured to receive and store 2 ml or less of the composition to be administered, wherein the plunger may in particular be configured to be used with a syringe barrel configured to receive and store 1 ml or less, such as 0.5 ml, of the composition, in particular a liquid dermal filler composition, such as a hyaluronic acid-based dermal filler.

[0049] In a possible, particularly preferred embodiment of the plunger according to the present invention, the plunger may be, particularly additionally, configured to be used for feeding or displacing a composition placed and stored in the internal cavity of a syringe barrel, from said internal cavity, wherein said internal cavity of said syringe barrel is defined by a cylindrical chamber having a smaller internal diameter and / or a larger size in the longitudinal direction compared to the dimensions of the internal cavity of a 1 ml syringe barrel according to the ISO 11040-6 standard.

[0050] In a possible, particularly preferred embodiment of the plunger of the present invention, the gripping pad on the plunger head is made of a thermoplastic elastomer (TPE), in particular a colored thermoplastic elastomer (cTPE). By using an injection molded TPE gripping pad, more convenient, precise and safe use can be ensured, and the user's thumb can be prevented from slipping during use. TPE as the gripping pad material can be easily applied to the proximally facing surface of the plunger head, and sufficient adhesion to the material of the proximally facing surface of the plunger head can be achieved.

[0051] To achieve the result of providing an advantageous plunger, the plunger head can be made of polypropylene (PP), in particular also by injection molding. Preferably, the plunger rod is also made of polypropylene, in particular also by injection molding, preferably in one piece with the plunger head. Accordingly, in one embodiment of the plunger of the present invention, the plunger is manufactured by 2K injection molding, wherein the plunger rod and the plunger head are preferably made of a first injection molding material, preferably in one piece, in particular from polypropylene (PP), and the gripping pad is in particular made of a second injection molding material, in particular from TPE.

[0052] Preferably, the gripping pad is applied directly to the proximally facing surface of the plunger head during its manufacture. This means that, in another alternative embodiment, the gripping pad may also be formed separately from the plunger, and thus the plunger head, and then attached to the proximally facing surface of the plunger head.

[0053] Furthermore, in another embodiment of the plunger of the present invention, the plunger shaft and / or plunger head may be made of a material other than polypropylene, in particular another suitable plastic. However, the material from which the plunger is made, in particular, has properties similar to polypropylene.

[0054] Instead of TPE, the grip pad can also be made of another material, particularly another suitable plastic. However, the selected grip pad material is preferably a rubber-like material or other high-friction material that also prevents the user's thumb from slipping and ensures comfortable, precise, and safe use.

[0055] The plunger is manufactured by 2K injection molding, which ensures reliable adhesion between the grip plate and the proximal surface of the plunger head, and the plunger manufacturing process is easy and advantageous.

[0056] In one embodiment according to the present invention, the grip pad can be at least partially colored, in particular completely colored, wherein the grip pad can be made of a colored material, for example, as described above, from colored TPE. This can be achieved, for example, by adding dye particles to the injection molding raw material. The use of a plunger containing a colored grip pad makes it possible to provide multiple syringe assemblies or kits, each of which is pre-filled with a (different) composition for administration, wherein each composition or content preferably corresponds to a predetermined color, based on which the user can differentiate between the syringe assemblies and / or kits. This facilitates immediate visual differentiation by the physician between different products, and accordingly, different syringe assemblies or kits pre-filled with different compositions for different use cases.Thus, a colored grip pad significantly improves ease of use and safety. Specifically, it can reduce the likelihood of mixing up syringe components or kits, as a colored grip pad can be visually identified much more easily than any prompt or instruction in the accompanying instructions for use. Consequently, by using a colored grip pad, the likelihood of misadministration, particularly mixing up the compositions to be administered, can be conveniently and easily reduced.

[0057] To ensure sufficient adhesion of the gripping pad on the proximally facing surface of the plunger head, in one embodiment of the present invention, the plunger head can be manufactured by means of an injection molding tool having a surface by means of which the proximally facing surface of the plunger head is molded and which has been processed to obtain a tool surface roughness in the range from VDI 3400 Ref 21 to VDI 3400 Ref 30, that is, in the range from Ra = 1.12 μm to Ra = 3.15 μm with Rmax in the range from 4.5 μm to 12.5 μm, wherein, in particular, the tool surface has been etched to provide a surface roughness in accordance with VDI 3400 Ref 27, characterized by Ra = 2.25 μm and Rmax = 9.0 μm.

[0058] To further improve the adhesion of the gripping pad to the proximally facing surface of the plunger head, in one embodiment of the plunger of the present invention, the proximally facing surface of the plunger head may comprise at least one recess, in particular at least one groove, wherein in the position in which the gripping pad is attached to the proximally facing surface of the plunger head, said at least one recess is filled with the injection molding material of the gripping pad. Due to such a recess, a larger contact area can be achieved between the proximally facing surface and the material of the gripping pad, which leads to improved adhesion and, accordingly, an improved connection between the material of the plunger head and the material of the gripping pad.

[0059] Preferably, the depth of at least one recess in the direction perpendicular to the proximally facing surface is from 0.5 mm to 2 mm, preferably about 1 mm.

[0060] In a particularly advantageous embodiment of the plunger of the present invention, the proximally facing surface of the head of the plunger may comprise two such recesses or grooves, in particular annular grooves, arranged concentrically, preferably in such a way that their center is aligned with the longitudinal axis of the plunger.

[0061] To ensure a comfortable and secure grip, in particular to ensure a comfortable and secure contact with the user's thumb, the average thickness of the grip pad, in particular in the area outside the grooves and / or recesses, is preferably in the range of 0.1 mm to 0.5 mm, and in particular is approximately 0.2 mm.

[0062] In one embodiment of the plunger of the present invention, the grip pad on the plunger head is designed to display a symbol, in particular a letter or other character, preferably selected from the ASCII table. Thus, in particular in addition to or as an alternative to a colored grip pad, a plunger with a visually detectable distinguishing feature can be easily provided. This facilitates immediate visual differentiation by the physician between different products, and accordingly, between different syringe assemblies or kits prefilled with different compositions for different use cases. This significantly contributes to improved ease of use and safety.In particular, the likelihood of mixing up syringe components or kits can be reduced, as the symbol on the grip pad can be visually identified much more easily than any prompt or instruction in the accompanying instructions for use. Consequently, by using such a grip pad, the likelihood of misadministration, particularly mixing up the compositions to be administered, can be conveniently and easily reduced.

[0063] For example, the grip plate may be designed to display one of the following symbols: "+", "-", "L", or the like. For example, the "+" or "L" symbol may indicate the fact that the composition to be administered, placed and stored in the inner cavity of the syringe barrel of the syringe assembly or kit, contains a specified active ingredient, for example, an anesthetic such as lidocaine or the like. For example, the "-" symbol may indicate the fact that the composition contained in the syringe assembly or kit does not contain the specified or specified active ingredient.

[0064] In one embodiment of the plunger of the present invention, the symbol can be displayed by areas that are not filled or covered by the injection-molded grip material, but are at least partially surrounded by the injection-molded grip material. This means that the symbol can be visualized by negative imaging.

[0065] Alternatively, but also possible and in some cases more preferable, the symbol may be displayed by areas filled or covered with the injection-molded grip material and at least partially or completely surrounded by unfilled areas. This means that in this case, the symbol is rendered by positive imaging.

[0066] In a possible, particularly preferred embodiment of the plunger of the present invention, the gripping pad attached to the plunger head is formed in one piece by injection molding, in particular with only one injection point. This allows for a very simple manufacturing process with only one injection molding step to form the gripping pad. This ensures a fast, easy, and reproducible manufacturing process for the gripping pad.

[0067] In one embodiment of the plunger of the present invention, the plunger comprises only a single gripping pad, preferably formed in one piece by injection molding. In particular, to form the gripping pad, the injection molding material of the gripping pad is applied directly to the proximally facing surface of the plunger head. This allows for a very simple manufacturing process with only a single injection molding step to form the gripping pad. This allows for a fast and easily reproducible manufacturing process for the gripping pad.

[0068] In one embodiment of the plunger according to the present invention, at least one injection point of the gripping pad material is located near the outer circumference of the gripping pad, in particular in the outer third of the diameter of the gripping pad or in the outer third of the distance from the center of the gripping pad to the outer circumference of the gripping pad, in particular in the case of a gripping pad made in one piece using only one injection point. This ensures a very uniform distribution of the injection molding material, in particular in the case where the proximally facing surface of the plunger head has a slightly concave shape to provide a more ergonomic contact area with the user's thumb.

[0069] In one embodiment of the plunger of the present invention, the plunger shaft at its distal end may also be configured to receive a piston, wherein the plunger shaft in particular may be configured to be connected to the piston at its distal end via a snap-fit ​​connection. This allows for a plunger to be provided to which the piston can be easily attached in a space-saving manner. This space-saving design is particularly desirable for use with a syringe barrel having a small inner diameter.

[0070] To achieve an advantageous snap-fit ​​connection between the distal end of the plunger shaft and the piston, particularly the proximal end of the piston, the plunger shaft may have a tip in the shape of a truncated cone or a tip in the shape of a mushroom, or the like. Furthermore, the plunger shaft may comprise a piston-receiving portion adjacent to the tip in the proximal direction and having a smaller diameter compared to the diameter of the tip. To provide an advantageous snap-fit ​​connection, the piston may be made of a suitable biocompatible elastomer material or may at least partially comprise said material.The plunger rod tip's truncated cone or mushroom-shaped geometry at the distal end of the plunger rod allows for virtually error-free assembly of the plunger with the distal end of the plunger rod, eliminating the need for torque, while simultaneously ensuring a tight and secure connection. Furthermore, this geometry is easier to manufacture and saves space compared to a threaded connection between the distal end of the plunger rod and the plunger.

[0071] To ensure axial fixation of the piston at the distal end of the plunger rod and to transmit the applied displacement force at the proximal end of the piston receiving portion, the plunger rod may comprise a flat disk extending in the radial direction that functions as a stop in the proximal direction.

[0072] In one embodiment of the plunger of the present invention, the plunger, in particular the plunger shaft, may be configured to be subjected to significant displacement forces, such as those that occur, for example, during the release of high-viscosity fluids, for example, during the release of a dermal filler, such as hyaluronic acid-based dermal fillers or the like.

[0073] In order to achieve sufficient mechanical strength of the plunger, in particular the plunger rod, in particular to achieve sufficient fracture resistance, which means sufficient fracture resistance, in particular in the case where the plunger is designed to be used with a 1 ml syringe barrel according to the ISO 11040-6 standard or with a syringe barrel having a smaller internal diameter compared to a standard 1 ml syringe barrel, the plunger rod may comprise at least one section along its longitudinal direction having at least essentially a double T-shaped profile shape, a double T-shaped profile-like shape, an I-shaped profile shape, or a shape similar to an I-shaped profile, or a similar shape.To ensure increased mechanical strength, the plunger shaft may have at least one section in its longitudinal direction having a double mushroom-shaped profile, a mushroom-like profile, a combined mushroom-T-shaped profile, or the like, in particular with a convex or curved external geometry. In some cases, it may be advantageous to have the plunger shaft have this shape along its entire length. Sufficient mechanical strength of the plunger, in particular the plunger shaft, allows for the provision of a plunger suitable for the release and injection of high-viscosity fluids, such as dermal fillers such as hyaluronic acid-based dermal fillers. Ensuring greater mechanical strength may reduce the likelihood of mechanical failure and, accordingly, enhance safety.

[0074] To achieve high resistance of the plunger to fracture, and accordingly, high mechanical strength of the plunger rod, in some cases a solid cross-section of the rod may be more preferable, in particular an oval or round or square cross-section, wherein said solid, in particular oval or round or square cross-section may extend along only one section of the length of the plunger rod or along several sections in the longitudinal direction of the plunger rod, or may extend along the entire length of the plunger rod. The geometry and / or size of the cross-sectional area of ​​the plunger rod, in particular the diameter, may be constant or vary along the length of the plunger rod. However, a constant geometry and / or size of the cross-sectional area is preferable in the longitudinal direction of the plunger rod within at least one section of the plunger rod.The geometry and / or size of the cross-sectional area, in particular the diameter of the cross-sectional area of ​​the plunger rod, may vary in different sections of the plunger rod or may be the same along the entire length of the plunger rod. In one embodiment, the geometry and / or size of the cross-sectional area of ​​the plunger rod may be constant over at least 50%, 60%, 70%, 80%, 90%, or 95% of the total length of the plunger rod. Thus, in some cases, advantageous mechanical properties can be achieved. This further simplifies the manufacturing process of the plunger rod. In some cases, this also allows for the use of a different, particularly more advantageous, material for the push rod.

[0075] The second aspect of the present invention is a method for manufacturing a plunger according to the above description, wherein according to the present invention, the method for manufacturing such a plunger includes at least the steps of manufacturing, in particular, at least the head of the plunger and forming a gripping pad by injection molding.

[0076] In one embodiment of the method for manufacturing a plunger according to the present invention, the head of the plunger can also be manufactured by injection molding, in particular in one piece with the plunger rod, wherein the head of the plunger and / or the plunger rod are preferably made of polypropylene (PP), in particular made in one piece as a single part.

[0077] Alternatively, the plunger head and / or the plunger rod may be made separately and / or from a different material, wherein each plunger rod and, in particular, the plunger head are made from a material having properties similar to those of polypropylene (PP).

[0078] In one embodiment, in particular in a preferred embodiment of the method for manufacturing a plunger according to the present invention, the gripping pad is formed by applying the injection molding material of the gripping pad directly to the proximally facing surface of the head of the plunger, wherein the gripping pad is in particular made in one, preferably only with one injection point, which is in particular located in the outer third of the gripping pad in the radial direction.

[0079] The third aspect of the present invention relates to a finger grip for a syringe assembly for administering a liquid composition, wherein the finger grip according to the present invention comprises a finger grip body with two flanges or wings extending radially in opposite directions from a central channel in the finger grip body, wherein a plunger of the syringe assembly, in particular a plunger according to the present invention, can be inserted through said central channel. Each flange is configured to function as a part of the grip and has a finger contact area on which at least one finger of the user can be partially placed during insertion to provide support to said finger during insertion, wherein each flange comprises a proximally facing surface and a distally facing surface.According to the present invention, the finger grip comprises a gripping pad attached to the distally facing surface of at least one of the flanges or wings of the finger gripping body, wherein the gripping pad extends at least partially over said distally facing surface and is made by injection molding.

[0080] By providing a grip pad attached to the distally facing surface of the finger grip, a finger grip with a comfortable and less slippery finger contact area can be achieved. This makes the syringe assembly comprising the finger grip more convenient, precise, and safe to use. The reduced likelihood of finger slippage achieved by the grip pad significantly improves safety during use, particularly during injection. By providing the grip pad, an improved grip can be achieved, resulting in more controlled use, particularly when using the finger grip in the syringe assembly for administering highly viscous fluids, such as in the case of injection or administration of dermal fillers, particularly hyaluronic acid-based dermal fillers that require increased extrusion force.Using injection molding to produce the finger grip pad allows for very easy and cost effective production of the grip pad.

[0081] The term "finger grip" as used herein refers to a handle, and accordingly, to a gripping device, adapted to be gripped at least partially by the fingers of a user, in particular a physician, to provide support for at least a first finger and a second finger during insertion when using the finger grip in a syringe assembly.

[0082] In particular, the finger grip is designed with the possibility of connection, preferably a detachable connection, with the syringe barrel, in particular with the proximal end of the syringe barrel, to ensure a comfortable grip of the syringe barrel for administering a composition placed and stored in the internal cavity of said syringe barrel.

[0083] To ensure easy connection with the syringe barrel, the finger grip, in particular the finger grip body, may comprise a slot into which the proximal flange of the syringe barrel can be inserted from the side, which is disclosed, for example, in WO 2017 / 176476 A1 or the like.

[0084] The central channel of the finger grip body may be partially open along its circumference or completely closed in the circumferential direction. A central channel made open in the circumferential direction allows for the preliminary assembly of the syringe barrel and plunger, i.e., at least partial insertion of the plunger into the internal cavity of said barrel, before connecting the finger grip body to the syringe barrel, as well as insertion of the plunger from the side into said central channel. A central channel having a completely closed circumference requires insertion of the plunger after connecting the syringe barrel to the finger grip body, wherein the plunger must be inserted along the longitudinal axis of the syringe barrel and perpendicular to the diameter of the central channel.

[0085] Preferably, the finger grip, in particular the two flanges of the finger grip, are configured to be gripped by a single finger. To ensure an ergonomic grip, at least one of the flanges is curved, preferably having a concave proximal side and a convex distal side. Preferably, one of the flanges or wings is configured to be gripped by the index finger, and the other is configured to be gripped by the middle finger of the user's hand.

[0086] In a possible, particularly preferred embodiment of the finger grip according to the present invention, the finger grip may be configured to be used in a syringe assembly comprising a syringe barrel configured to receive and store 2 ml or less of a composition to be administered, wherein the finger grip may in particular be configured to be used, in particular connected, with a syringe barrel configured to receive and store 1 ml or less, for example 0.5 ml, of a composition, in particular a liquid dermal filler composition, for example a dermal filler based on hyaluronic acid.

[0087] In one embodiment of the finger gripper of the present invention, at least one grip pad of the finger gripper is formed by applying the injection molding material of the grip pad directly to the distally facing surface of the corresponding flange. This means that in another alternative embodiment, the grip pad can also be formed separately from the finger gripper, and accordingly, the finger gripper body, and can then be attached to the distally facing surface of the corresponding flange or wing of the finger gripper.

[0088] In one embodiment of the finger grip according to the present invention, at least one grip pad of the finger grip is made of a thermoplastic elastomer (thermoplastic elastomer, TPE), in particular a colored thermoplastic elastomer (colored thermoplastic elastomer, cTPE).

[0089] The use of an injection-molded TPE grip pad ensures more comfortable, precise, and safe use, and prevents the user's fingers from slipping during use. TPE as the grip pad material can be easily applied to the distally facing flange surfaces of the finger gripper, achieving sufficient adhesion to the flange surface material.

[0090] To achieve an advantageous result or to provide an advantageous finger grip, the finger grip body can be made of polypropylene (PP), in particular also by injection molding. Accordingly, in one embodiment of the finger grip according to the present invention, the finger grip is manufactured by two-stage injection molding (2K-injection molding), wherein the finger grip body, including the flanges, is preferably made of a first injection molding material, preferably in one step, in particular from polypropylene (PP), and the grip pad is made of a second material by injection molding, in particular from TPE.

[0091] In another embodiment of the finger grip according to the present invention, the finger grip, in particular the finger grip body, can be made of a material other than polypropylene, in particular another suitable plastic. However, the material from which the finger grip is made, in particular, has properties similar to polypropylene.

[0092] Instead of TPE, the grip pad can also be made of another material, particularly another suitable plastic. However, the selected grip pad material is preferably a rubber-like material or other high-friction material that also prevents the user's fingers from slipping and ensures comfortable, precise, and safe use.

[0093] The finger gripper is manufactured by 2K injection molding, which ensures reliable adhesion between the grip plate and at least one of the distally facing surfaces of the finger gripper, and also provides an easy and advantageous manufacturing process for the finger gripper.

[0094] In one embodiment of the present invention, the grip pad attached to the body of the finger grip may be at least partially colored, in particular completely colored, wherein the grip pad may be made of a colored material, for example, as described above, of colored TPE. This can be achieved, for example, by adding dye particles to the injection molding raw material. The use of a finger grip containing a colored grip pad allows for the provision of multiple syringe assemblies or kits, each of which is pre-filled with a (different) composition for administration, wherein each composition or content preferably corresponds to a predetermined color, based on which the user can distinguish between the syringe assemblies and / or kits.This facilitates immediate visual differentiation by the physician between different products, and therefore between different syringe assemblies or kits prefilled with various formulations for different use cases. Thus, a colored grip pad significantly improves ease of use and safety. In particular, the likelihood of mixing up syringe assemblies or kits can be reduced, as a colored grip pad can be visually identified much more easily than any prompt or indication in the accompanying instructions for use. Consequently, by using a colored grip pad, the likelihood of incorrect administration, particularly mixing up the formulations to be administered, can be conveniently and easily reduced.

[0095] In order to ensure sufficient adhesion of the grip pad on at least one of the distally facing surfaces of the finger grip, in one embodiment of the present invention, the finger grip body can be manufactured by means of an injection molding tool having a surface by means of which the distally facing surface of the finger grip is molded, wherein said surface of the tool has been processed to provide a surface roughness of the tool in the range from VDI 3400 Ref 21 to VDI 3400 Ref 30, that is, to provide a roughness in the range from Ra = 1.12 μm to Ra = 3.15 μm with Rmax in the range from 4.5 μm to 12.5 μm, wherein, in particular, the surface of the tool has been processed to provide a surface roughness in accordance with VDI 3400 Ref 27, characterized by Ra = 2.25 μm and Rmax = 9.0 μm.

[0096] To ​​further improve the adhesion of the gripping pad with at least one distally facing surface of the finger gripper body, in one embodiment of the finger gripper of the present invention, at least one distally facing surface of the finger gripper body may comprise at least one recess, in particular at least one groove, wherein in the position in which the gripping pad is attached to said surface of the finger gripper body, said at least one recess is filled with the injection molding material of the gripping pad. Due to such a recess, a larger contact area can be achieved between the distally facing surface and the material of the gripping pad, which leads to improved adhesion, and accordingly, an improved connection between the material of the finger gripper body and the material of the gripping pad.

[0097] Preferably, the depth of at least one recess in the direction perpendicular to the distally facing surface is from 0.5 mm to 2 mm, preferably about 1 mm.

[0098] To ensure a comfortable and safe grip, in particular to ensure a comfortable and safe contact with the user's fingers, the average thickness of at least one finger grip pad, in particular in the region outside the grooves and / or recesses, is preferably in the range of 0.1 mm to 0.5 mm and in particular is approximately 0.2 mm.

[0099] In one embodiment of the finger grip according to the present invention, the grip pad on the finger grip is designed in such a way that at least one region of the distally facing surface of the finger grip, not filled or not covered with the injection molding material of the grip pad, is completely surrounded by the injection molding material.

[0100] In a preferred embodiment of the finger grip according to the present invention, the area not filled or covered with the injection molding material of the grip lining comprises one or more strips, in particular at least two parallel strips, preferably extending in the longitudinal direction of the corresponding flange or wing, respectively, in the transverse direction of the finger grip.

[0101] Alternatively, the grip pad on the finger grip can be designed to display a symbol, in particular a letter or other character, preferably selected from the ASCII table. Thus, in particular in addition to or as an alternative to a colored grip pad, a finger grip with a visually distinguishable feature can be easily provided. This facilitates immediate visual differentiation by the physician between different products, and accordingly, different syringe assemblies or kits pre-filled with different compositions for different use cases. This significantly contributes to increased ease of use and safety. In particular, the likelihood of mixing up syringe assemblies or kits can be reduced, since the symbol on the grip pad can be visually identified much more easily compared to any prompt or indication in the accompanying instructions for use.Therefore, by using such a grip pad, the possibility of incorrect administration, in particular, confusion of the compositions to be administered, can be reduced in a convenient and simple manner.

[0102] Also, the grip overlay on the finger grip can be designed in such a way that it displays one of the following symbols: "+", "-", "L", etc.

[0103] In one embodiment of the finger grip according to the present invention, the symbol can be displayed by areas that are not filled or covered by the injection-molded material of the grip pad, which are at least partially surrounded by the injection-molded material of the grip pad. This means that the symbol can be visualized by negative imaging.

[0104] In an alternative, but also possible and in some cases more advantageous embodiment, the symbol may be displayed by areas filled with the injection-molded grip material and at least partially or completely surrounded by unfilled areas. This means that in this case, the symbol is rendered by positive imaging.

[0105] In a possible, particularly preferred embodiment of the finger grip according to the present invention, the grip plate attached to the finger grip body is formed in one piece by injection molding, in particular with only one injection point. This allows for a very simple manufacturing process with only one injection molding step to form the grip plate. This ensures a fast and easily reproducible manufacturing process for the grip plate.

[0106] In one embodiment of the finger gripper according to the present invention, each flange of the finger gripper body comprises only one gripping pad, preferably formed in one piece by injection molding, wherein, in particular, to form the gripping pad, the injection molding material of the gripping pad is applied directly to the distally facing surface of said flange. This allows for a very simple manufacturing process with only one injection molding step to form the gripping pad. Thus, a fast and easily reproducible manufacturing process for the gripping pad is ensured.

[0107] In one embodiment of the plunger according to the present invention, at least one injection point of the gripping pad material is located near the outer circumference of the gripping pad, in particular in the outer third of the diameter of the gripping pad or in the outer third of the distance from the center of the gripping pad to the outer circumference of the gripping pad, in particular in the case of the gripping pad being manufactured in one piece using only one injection point. This ensures a very uniform distribution of the injection molding material.

[0108] The fourth aspect of the present invention relates to a method for manufacturing an open finger grip, wherein, according to the present invention, the method for manufacturing such a finger grip includes at least the steps of:

[0109] - manufacturing a finger grip body comprising two flanges or wings extending radially in opposite directions from a central channel in the finger grip body, wherein a plunger of a syringe assembly can be inserted through said central channel, wherein each flange functions as a part of the grip and has a finger contact area on which at least one finger of the user can be partially placed during insertion to provide support to said finger during insertion, and wherein each flange comprises a proximally facing surface and a distally facing surface, and

[0110] - forming the grip lining by injection molding.

[0111] In one embodiment, particularly in a preferred embodiment, the finger grip is also made of plastic, in particular polypropylene, in particular also by injection molding. Preferably, the finger grip is entirely manufactured by two-stage injection molding (2K injection molding), wherein the finger grip body is preferably made of a first injection molding material, and the grip pad is made of a second injection molding material, in particular TPE.

[0112] In one embodiment, in particular in a preferred embodiment of the method for manufacturing a finger grip according to the present invention, the grip pad is formed by applying the injection molding material of the grip pad directly to at least one of the distally facing surfaces of the finger grip body, wherein the grip pad is, in particular, made in one, preferably only with one injection point, which, in particular, is located in the outer third of the grip pad in the radial or transverse direction.

[0113] The fifth aspect of the present invention relates to a syringe assembly for administering a liquid composition into the body of a human or animal, in other words, any patient, at least comprising a longitudinal syringe barrel having an internal cavity for receiving and storing a liquid composition to be administered, a finger grip connected to the proximal end of said barrel, and a plunger having a plunger shaft and a plunger head, wherein the plunger shaft is located at least partially inside the internal cavity of the distal end of the barrel. The syringe assembly according to the fifth aspect of the present invention is characterized in that the plunger is a plunger according to the present invention or a plunger manufactured by the method according to the present invention, and / or in that the finger grip is a finger grip according to the present invention and / or a finger grip manufactured by the method according to the present invention.

[0114] The syringe assembly as a whole may be a unit for administering a single-component liquid composition or a two-component or multi-component liquid composition. However, in a preferred embodiment, the syringe assembly is configured to administer a single-component ready-to-use mixed composition.

[0115] In one embodiment of the present invention, the syringe barrel of the syringe assembly is made of plastic, in particular a cycloolefin copolymer (COC). Using a syringe barrel made of plastic reduces the risk of needle breakage during administration, in particular during the release or injection of highly viscous fluids such as dermal filler, since a plastic barrel can provide a better connection between the syringe and the needle compared to a barrel made of glass.

[0116] Furthermore, the use of plastic as the syringe barrel material allows for the provision of a syringe barrel containing a Luer Lock connector integrally formed with the barrel. This reduces the likelihood of needle detachment and / or separation between the needle or cannula assembly and the syringe barrel. Furthermore, the plastic syringe barrel can be easily manufactured using injection molding, allowing for the production of syringe barrels with lower manufacturing tolerances, resulting in more reliable needle-syringe connections and lower expulsion force during injection of the contents stored within the syringe barrel. Furthermore, improved geometric accuracy of the syringe barrel can be achieved, ensuring a more precise, durable, and reliable connection between the finger grip and the plunger with the syringe barrel.Moreover, the failure rate of the barrel flange of a plastic syringe can be reduced compared to a glass syringe.

[0117] The inner surface of the syringe barrel can be siliconized. This can reduce the extrusion force.

[0118] In one embodiment of the present invention, the syringe barrel of the syringe assembly of the present invention may have an internal cavity for receiving and storing a volume of 2 ml or less of the composition to be administered, wherein the syringe barrel, in particular, may be configured to receive and store 1 ml or less, such as 0.5 ml, of the composition, in particular a liquid dermal filler composition, such as a hyaluronic acid-based dermal filler.

[0119] Therefore, the inner diameter of the syringe barrel's internal volume may be, for example, smaller than that of a standard syringe barrel according to ISO 11040-6, and preferably longer, with the diameter-to-length ratio preferably being approximately 5 / 70. A longer inner diameter of the syringe barrel has the advantage of reducing the displacing force compared to a syringe barrel according to ISO 11040-6. This results in easier, more controlled, and safer use. Furthermore, better control of the displaced volume can be achieved by displacing a smaller amount of product per millimeter of plunger longitudinal movement during dispensing.

[0120] By using the syringe assembly according to the present invention, a very easy-to-use, convenient and safe-to-use syringe assembly is provided for administering a liquid composition, in particular for administering a dermal filler, in particular for administering a dermal filler based on hyaluronic acid, wherein the syringe assembly, and accordingly, the individual parts of said syringe assembly are easy to manufacture and allow for convenient storage of the liquid composition and easy handling by a practitioner.

[0121] Siliconization of the inner cylinder surface has the advantage of allowing a sufficient layer of lubricant to be applied to the inner cylinder surface while maintaining a minimal amount of free silicone, preventing interaction with the dermal filler. Consequently, siliconization of the inner cylinder surface results in a lower ejection force, which also results in easier, more controlled, and safer use. Lower ejection force also helps reduce the likelihood of mechanical failure.

[0122] The grip pad and / or symbols included on the grip pad enhance ease of use and safety through easy visual recognition. Using a TPE grip pad allows for adequate finger contact, ensuring controlled and safer injection of the composition. Using a colored grip pad can further enhance visual recognition.

[0123] In one embodiment of the syringe assembly according to the present invention, the syringe barrel comprises a Luer Lock connector at its distal end, which is, in particular, formed integrally with the syringe barrel. Furthermore, the syringe assembly may, in particular, comprise a tip cap covering and sealing the distal end of the syringe barrel. Compared to a tapered Luer Lock connector, a Luer Lock connector has the advantage of enabling a more secure and fixed connection, which is also reversible.

[0124] Luer-type connections and connectors are generally known in the art and standardized, with Luer-type connections typically comprising a male Luer connector and a corresponding female Luer connector. For example, Luer-Lock connections are described in DIN EN ISO 80369-7:2017-10. They are characterized by a special 6% taper, with the Luer-Lock connection also comprising a threaded connection.

[0125] The tip cap may be a two-piece tip cap comprising a rigid portion and an elastomeric portion, wherein the maximum outer diameter of the rigid portion is preferably less than or equal to the outer diameter of the Luer Lock connector of the syringe barrel. This makes assembly, storage, unpacking, and use of the prefilled syringe assembly safer, as the likelihood of snagging and inadvertent removal or damage to the tip cap is reduced.

[0126] In one embodiment, the rigid portion may comprise an external thread and may be screwed and engaged with the internal thread of a Luer Lock connector of the syringe barrel, and the elastomeric portion of the tip cap may be inserted into the rigid portion and secured to the Luer taper of the Luer Lock connector with concomitant closure of the outlet port of the syringe barrel.

[0127] A sixth aspect of the present invention relates to a kit comprising parts of a syringe assembly according to the present invention, configured to be assembled to obtain a syringe assembly according to the present invention and according to the above description, wherein the kit comprises a longitudinal barrel of a syringe having an internal cavity for receiving and storing a liquid composition to be administered, a finger grip configured to be connected to the proximal end of said barrel, and a plunger having a plunger rod and a plunger head, wherein the plunger rod is configured to be placed at least partially within the internal cavity of the barrel with its distal end.The kit according to the present invention is characterized in that the plunger is a plunger according to the present invention or a plunger manufactured by the method according to the present invention, and / or the finger grip is a finger grip according to the present invention or a finger grip manufactured by the method according to the present invention, wherein, in particular, the plunger rod is designed with the possibility of insertion through the central channel of the finger grip body.

[0128] When using the kit according to the present invention, a very easy-to-use, convenient and safe to use kit is provided, comprising parts of a syringe assembly for administering a liquid composition, in particular for administering a dermal filler, in particular for administering a dermal filler based on hyaluronic acid, wherein the kit, and accordingly, the individual parts of said kit are easy to manufacture and allow for convenient storage of the liquid composition and easy handling by a practitioner.

[0129] In one embodiment of the kit of the present invention and / or the syringe assembly of the present invention, in particular in a preferred embodiment, the syringe barrel is pre-filled with, in particular, a liquid composition, in particular a soft tissue filler material, for example one of the following soft tissue filler materials:

[0130] - hyaluronic acid (hyaluronan) (HA),

[0131] - carboxymethylcellulose (CMC),

[0132] - calcium hydroxyapatite in suspension with a gel carrier such as CMC or collagen HA,

[0133] - other natural polysaccharide (alginate, heparosan, chitosan, etc.),

[0134] - synthetic filler material (such as polyethylene oxide, poly-L-lactic acid (PLLA), poly(methyl)methacrylate (PMA), polyacrylamide (PA), polyvinyl alcohol (PVA)) or

[0135] - liquid silicone for injection.

[0136] Typically, filler materials such as hyaluronic acid can be cross-linked or non-cross-linked. Additionally, soft tissue fillers may contain additional substances such as vitamins, antioxidants, local anesthetics (e.g., lidocaine), hydroxyapatite particles, etc.

[0137] Specifically, the syringe barrel can be pre-filled with a cross-linked hyaluronic acid (HA) filler material, in particular a dermal filler in the form of hyaluronic acid (HA) cross-linked with 1,4-butanediol diglycidyl ether (DGEBD).

[0138] The scope of use is not specifically limited. However, the most important use is for cosmetic purposes, such as wrinkle removal.

[0139] This means that, in general, the syringe assembly or kit of the present invention can be provided with an empty syringe barrel or a pre-filled syringe barrel. However, in a preferred embodiment, the syringe assembly or kit of the present invention is provided with a pre-filled syringe barrel, in particular, with a syringe barrel pre-filled with one of the aforementioned soft tissue filler materials.

[0140] The term "soft tissue filler" as used herein broadly refers to a material intended to provide additional volume in areas of soft tissue deficiency. The term "dermal filler" or "dermal filler composition" as used herein essentially refers to a substance that supplements, replaces, or increases the volume of soft tissues beneath the skin, resulting, for example, in smoothing out skin wrinkles, increasing lip volume, improving the appearance of the skin, or treating scars. The dermal filler composition of the present invention, such as a soft tissue filler, is typically configured for administration by injection. Furthermore, the dermal filler is typically used in the dermal region, such as beneath the epidermis or above the hypodermis, and accordingly, can be administered subcutaneously or intradermally, or in some combinations.

[0141] If necessary, the kit may contain instructions for use. "Instructions for use" may be, for example, instructions for use in the cosmetic field and / or for the administration of a soft tissue filler (e.g., a dermal filler) into the human body, including the replacement or filling of biological tissue or the augmentation of biological tissue for cosmetic purposes. Specifically, the kit may contain instructions for use as a soft tissue filler or dermal filler in cosmetic procedures.

[0142] The seventh aspect of the present invention relates to the use of a syringe assembly or kit according to the present invention, in particular in the field of cosmetic or therapeutic use, in particular for replacing or filling biological tissue or increasing the volume of biological tissue, wherein an effective volume of a liquid composition, in particular an effective volume of a dermal filler composition, is to be administered to a patient or is administered to a patient by using the syringe assembly according to the present invention and / or the kit according to the present invention.

[0143] The dermal filler composition can be essentially administered in an effective volume to a patient by injection, such as, for example, subcutaneous or intradermal injection. For example, the composition can be administered intradermally or subcutaneously using a sequential puncture method, preferably with an injection angle of at least 1, 2, 3, 5, 8, 10, 12, 15, 20, 25, 30, 35, 40 or 45 degrees to an injection angle of no more than 12, 15, 20, 25, 30, 35, 40, 45, 60, 75 or 90 degrees, wherein each of the aforementioned minimum values ​​​​can be combined with any of the aforementioned maximum values ​​​​of the injection angle. Accordingly, the insertion angle may be, for example, in the range of 8 to 25 degrees, or in the range of 12 to 60 degrees, or in the range of 5 to 15 degrees, etc. The term "insertion angle" as used herein refers to the angle between said first longitudinal axis of the injection needle and the line projected by the needle onto the skin surface.

[0144] Choosing the proper injection angle can ensure improved injection results. In many cases, shallow injection angles, such as those in the range of 2, 5, or 8 degrees to 12 or 15 degrees, offer significant advantages. In other cases, deeper injection angles, such as those in the range of 25, 30, or 45 degrees to 60 or 90 degrees, may be preferable.

[0145] The term "effective volume" refers to the volume of a soft tissue filler composition sufficient to achieve beneficial or desired cosmetic (aesthetic) results.

[0146] The term "patient" as used herein may refer to any individual or patient, such as a mammal and preferably a human, in need of treatment or application of a composition for cosmetic (aesthetic) purposes.

[0147] The present invention described above is further explained in the description of the following non-limiting embodiments and examples, in which additional optional features of the invention are disclosed in the drawings and in the description of said drawings. All features and all combinations of features disclosed in the above description and / or in the following description and / or only illustrated in the drawings can be implemented in an embodiment of the invention in a combination described or separately, or in at least one other combination not directly described, as long as said combination is technically feasible.

[0148] Brief description of drawings

[0149] The accompanying drawings, incorporated in and forming part of the present specification, schematically illustrate preferred embodiments of the invention described above, in particular the present invention, and these drawings, together with the description, serve to explain the principles and, at least in part, the features of the described invention, wherein like elements are designated by like reference numerals in the drawings. In the drawings:

[0150] FIG. 1 is a perspective view of a first example of an embodiment of a syringe assembly of the present invention, comprising a first example of a plunger of the present invention and an example of a finger grip of the present invention,

[0151] FIG. 2 is a perspective view of a second example of an embodiment of a syringe assembly of the present invention, comprising a second example of a plunger of the present invention and a finger grip identical to that shown in the syringe assembly of FIG. 1,

[0152] FIG. 3 - side view of the syringe assembly of FIG. 1,

[0153] FIG. 4 - longitudinal section of the syringe assembly according to FIGS. 1 and 3,

[0154] FIG. 5 is a top view of the proximally facing surface of the plunger of the syringe assembly of FIG. 1,

[0155] FIG. 6 - a top view of the proximally facing surface of the plunger of the syringe assembly of FIG. 2,

[0156] FIG. 7 - first side view of the plunger of FIG. 1,

[0157] FIG. 8 - first side view of the plunger of FIG. 1,

[0158] FIG. 9 - longitudinal section of the plunger according to FIG. 1,

[0159] FIG. 10 is an enlarged cross-sectional illustration of the plunger of FIG. 10 along line A-A',

[0160] FIG. 11 is an enlarged illustration of the distal end of the plunger of FIG. 9,

[0161] FIG. 12 is an enlarged illustration of the proximal end of the plunger of FIG. 9,

[0162] FIG. 13 is an enlarged illustration of a bottom view of the plunger of the syringe assembly of FIG. 4,

[0163] FIG. 14 is an enlarged cross-sectional illustration of the plunger of the syringe assembly of FIG. 4,

[0164] FIG. 15 is a first perspective view of the finger grip of the present invention of the syringe assembly illustrated in some of the previous drawings,

[0165] FIG. 16 - a second perspective view of the finger grip of FIG. 15,

[0166] FIG. 17 - top view of the finger grip of FIGS. 15 and 16,

[0167] FIG. 18 - side view of the finger grip of FIGS. 15-17,

[0168] FIG. 19 is a perspective view of the syringe barrel of the syringe assembly of FIG. 1,

[0169] FIG. 20 - longitudinal section of the syringe barrel according to FIG. 19, and

[0170] FIG. 21 is an enlarged illustration of the tip cap at the distal end of the syringe barrel of FIG. 20.

[0171] IMPLEMENTATION OF THE INVENTION

[0172] FIG. 1 shows a perspective view of a first example of an embodiment of a syringe assembly 100 according to the present invention, wherein said syringe assembly 100 comprises a first example of a plunger 20 according to the present invention and an example of a finger grip 30 according to the present invention, wherein the syringe assembly 100 is assembled from parts of an example of a kit according to the present invention, and wherein the plunger 20 and, accordingly, the finger grip 30 are made by the method of the present invention.

[0173] The syringe assembly 100 also comprises a syringe barrel 10 having an internal cavity 13 (see, for example, FIG. 4) pre-filled with a liquid composition (not shown), wherein the liquid composition is a hyaluronic acid-based dermal filler. The proximal end of the syringe barrel 10 is closed and sealed by a tip cap 40.

[0174] The plunger 20 can be moved into the syringe barrel 10 along the longitudinal axis A of said syringe barrel 10 to supply the composition stored in the internal cavity 13 (see, for example, FIG. 4) of said syringe barrel 10, in particular to expel said composition from the barrel 10 after removing the tip cap 40.

[0175] The plunger 20 comprises a plunger head 22 and a plunger shaft 21, each of which is made of polypropylene by injection molding, wherein the plunger head 22 and the plunger shaft 21 are formed in one piece. This means that they are molded in one piece. The plunger head 22 comprises a proximally facing surface 24, onto which a grip pad 23 is also applied by injection molding to facilitate gripping and, accordingly, to improve contact with the user's thumb. The grip pad 23 is made of a thermoplastic elastomer (TPE) to provide safe and accurate support for the user's thumb during the use of said syringe assembly 100 and, thus, the accurate administration of the composition stored in the barrel 10 of the syringe.

[0176] In this example of the plunger 20 according to the present invention, the gripping pad 23 attached to the head 22 of the plunger is formed integrally with only one injection point 26 (see FIG. 5). The gripping pad 23 extends over almost the entire proximally facing surface 24 of the head 22 of the plunger, except for some areas that are not filled or not covered with the material of the gripping pad 23. In this example of the plunger 20 according to the present invention, the areas that are not filled or not covered with the material of the gripping pad are completely surrounded by the material of the gripping pad 23.

[0177] Due to the fact that the hyaluronic acid-based dermal filler compositions stored in the barrel 10 of the syringe assembly 100 require a significant extrusion force and, accordingly, a significant force for release due to their high viscosity, the plunger rod 21 must be made resistant to fracture. In order to avoid mechanical breakage of the plunger rod 21 during use, the plunger rod 21 has a double mushroom-shaped profile along almost its entire length, see also FIGS. 4 and 7-10. In this way, a very high mechanical strength can be ensured, in particular also for the plungers 20 configured for use with the syringe barrels 10 for the syringe assemblies 100 and 200, as shown in FIG.1 and 2, which are designed to receive and store 1 ml of the composition to be administered, wherein the internal cavity 13 of the barrel 10 of the syringe has a relatively small internal diameter, in particular a smaller internal diameter and a greater length compared to the internal cavity of a standard syringe barrel according to the ISO 11040-6 standard. Due to the use of a reduced internal diameter of the internal cavity 13, i.e. its smaller internal diameter, the displacement force during use can be reduced, which also helps to reduce the likelihood of mechanical breakage of the plunger 20, in particular the plunger rod 21.In an alternative embodiment, the plunger rod 21 may comprise a solid cross-section, in particular an oval or circular or square cross-section, wherein said solid, in particular oval or circular or square, cross-section may extend along only one portion of the length of the plunger rod 21 or along several portions in the longitudinal direction of the plunger rod 21, or may extend along the entire length of the plunger rod 21. The size and geometry of the cross-section of the plunger rod 21 may be constant along the entire length of the plunger rod 21 or may vary. In one embodiment, the geometry and / or size of the cross-sectional area of ​​the plunger rod may, for example, be constant along at least 80% or 90% of the total length of the plunger rod.

[0178] The finger grip 30 comprises a finger grip body, also made in one piece by injection molding of polypropylene and comprising two flanges or wings 31 and 32 extending radially in opposite directions from the central channel 37 in the finger grip body. The plunger 20 is inserted through the central channel 37. The wings 31, 32 extend to the right, and, respectively, to the left relative to the central channel 37. Each wing 31, 32 performs the function of a part of the grip and has a finger contact area 35, on which at least one finger of the user can be partially placed during the introduction of the composition stored in the barrel 10 of the syringe, to provide support to the said finger during the introduction, wherein each wing 31, 32 comprises a distally facing surface 33 and a proximally facing surface 34.

[0179] According to the present invention, the finger grip 30 comprises at least one gripping pad 35, and in this example comprises two gripping pads 35, wherein each gripping pad is attached to the distally facing surface 33 of one of the wings 31, 32 and extends over almost the entire distally facing surface 33. Both gripping pads 35 are manufactured by injection molding, and the gripping pads 35 in this example of the finger grip 30 of the present invention are applied directly to the distally facing surfaces 33 during the injection molding process.

[0180] The grip pads 35 attached to the flanges 31 and 32 are also made in one piece from a thermoplastic elastomer (TPE), and in the manufacture of each of them, only one injection point 26 is used (see FIGS. 16 and 17). These grip pads 35 also facilitate the grip of the syringe assembly 100 and help prevent the user's fingers from slipping during the injection of the composition stored in the barrel 10 of the syringe.

[0181] The grip pads 35 of the finger grip 30 also comprise regions 36 that are not filled with the injection molding material of the grip pads 35, said regions forming parallel and transversely extending strips 36 that are completely surrounded by the material of the grip pads 35.

[0182] The finger grip 30 is connected to the proximal end of the syringe barrel 10 by means of a flange 12 (see, for example, FIG. 4) formed on the proximal end of the syringe barrel 10, wherein the flange 12 is inserted into a lateral slot 38 in the finger grip 30 (see, for example, FIG. 4). Through the central channel 37, the rod 21 of the plunger 20 is inserted in such a way that the rod 21 of the plunger is at least partially located with its distal end in the internal cavity 13 of the syringe barrel 10.

[0183] To easily distinguish and prevent improper administration of the composition stored in the barrel 10 of the syringe assembly 100, the grip pad 23 attached to the head 22 of the plunger and the grip pads 35 attached to the body 30 of the finger grip and, respectively, to its wings 31 and 32, are made of a colored grip pad material, in particular from colored TPE, wherein said specific composition of the hyaluronic acid-based dermal filler stored in the barrel 10 of the syringe is assigned a specific color. This allows the physician to determine at a glance the composition contained in the corresponding syringe assembly 100 that said physician intends to use.

[0184] FIG. 2 shows a second example of an alternative embodiment of the syringe assembly 200 of the present invention, wherein in this embodiment 200, the gripping pad 23 attached to the head 22 of the plunger, in particular its proximally facing surface 24, is designed in such a way that it displays a symbol, in particular a "+" symbol. In this case, said "+" symbol is assigned to a composition containing lidocaine as an active ingredient. This design of the gripping pad 23 of the plunger 20 allows the physician to determine at a glance that the syringe assembly 200 filled with a composition containing lidocaine has been selected. Thus, the possibility of improper administration due to confusion of syringe assemblies containing different compositions for administration can be reduced.

[0185] FIG. 3 shows a side view of the syringe assembly 100 of FIG. 2, and this drawing clearly shows the arrangement of the gripping pads 35 on the finger grip 30, in particular on its distally facing surfaces 33.

[0186] FIG. 4 shows a longitudinal section of the syringe assembly 100 of FIGS. 1 and 3, and this drawing shows the connection of the plunger 20, in particular the plunger rod 21, with the syringe barrel 10 and the finger grip 30, as well as the connection between the finger grip 30 and the syringe barrel 10.

[0187] In particular, the drawing of FIG. 4 shows the process of inserting the flange 12 at the proximal end of the syringe barrel 10 into the slot 38 in the finger grip 30 to ensure the connection of the syringe barrel 10 with the body 30 of the finger grip. In addition, the drawing shows that the distal end of the plunger rod 21 is inserted through the central channel 37 into the internal cavity of the syringe barrel 10. At its distal end 25, the plunger 20 is connected to the piston 50, in particular by means of a snap connection, wherein the piston 50 in this example of the syringe assembly 100 is made of FM257, which is an elastomeric material.

[0188] In order to achieve sufficient adhesion between the gripping pad 23 and the proximally facing surface 24 of the head 22 of the plunger and between the gripping pads 35 and the distally facing surfaces 33 of the body 30 of the finger grip, each of the surfaces onto which the gripping pads 23 and 35 are applied, respectively, contains several grooves 27, 39 (see FIGS. 4 and 12) filled with the injection molding material of the gripping pads during the injection molding process of the gripping pads 23, 35.

[0189] FIG. 4 also shows in detail the closing and sealing of the distal end of the syringe barrel 10 by the tip cap 40. To ensure the connection of said tip cap 40 with the syringe barrel 10, the syringe barrel 10 has a Luer Lock connector 11 at its distal end. The tip cap 40 has a rigid outer part 41 and an elastomeric inner part 42. The rigid outer part 41 is in a threaded connection with the internal thread of the Luer Lock connector 11. The elastomeric inner part 42 of the tip cap 40 is inserted into the rigid outer part 41 and partially extends in the form of a truncated cone-shaped protrusion into the outlet channel 15 of the distal end of the syringe barrel 10, see also FIGS. 20 and 21.

[0190] FIG. 5 shows a top view of the plunger 20 of the syringe assembly 100 of FIG. 1, wherein FIG. 5 shows a single injection point 26 used to produce the gripping pad 23 in one go. In this example, the injection point 26 is located near the outer edge of the gripping pad 23. In order to improve the adhesion of the injection molding material of the gripping pad 23 to the proximally facing surface 24 of the head 22 of the plunger 20, the plunger 20 is manufactured by means of an injection molding tool (not shown) comprising a tool surface that causes the molding of the proximally facing surface 24 and is processed to provide a surface roughness according to VDI 3400 Ref 27 with Ra = 2.24 μm and Rmax = 9.0 μm.

[0191] FIG. 6 shows a top view of the plunger 20 of the syringe assembly 200 of FIG. 2, in which the gripping pad 23, attached to the proximally facing surface 24 of the head 22 of the plunger of said plunger 20, is also formed in one piece by injection molding using only one injection point 26. The injection point 26 is also located near the outer edge, and accordingly, the outer circumference of the gripping pad 23. Unlike the gripping pad 23 of the plunger 20 of FIG. 5, the gripping pad 23 of the plunger of FIG. 6 is designed in such a way that it displays a symbol, in particular the "+" symbol, as described above in the context of FIG. 2, by means of which it is indicated that the composition with which the cylinder 10 of the syringe of the syringe assembly 200 is pre-filled contains lidocaine.

[0192] FIGS. 7 and 8 show different side views of the plunger 20 of the syringe assembly 100 of FIG. 1, wherein FIG. 8 shows the plunger 20 rotated approximately 90° about its longitudinal axis A compared to the illustration in FIG. 7.

[0193] FIG. 9 illustrates a longitudinal section of the plunger 20 of FIGS. 1, 7 and 8, wherein FIG. 9 shows the double mushroom-shaped profile of the plunger rod 21.

[0194] FIG. 10 shows an enlarged illustration of a cross-section of the plunger of FIG. 10 along the section line A-A', as a result of which the double profile of the plunger rod 21 is visible in the drawing.

[0195] FIG. 11 shows an enlarged illustration of the distal end 25 of the above-described plunger 20 of FIG. 9, wherein the plunger rod 21 can be connected at its distal end 25 to the piston by means of a snap connection (see, for example, FIGS. 4 and 14, piston 50). The distal end 25 of the plunger rod 21 comprises a mushroom-shaped tip 25A. In this example, the plunger tip 25 also comprises a piston receiving portion 25B formed near the mushroom-shaped tip 25A in the proximal direction and having a smaller diameter compared to the diameter of the mushroom-shaped tip 25A. The piston receiving section 25B is limited in the proximal direction by a flat, disc-shaped axial piston stop 25C for axial fixation of the piston (not shown in the drawing). This allows for a secure connection between the distal end 25 of the plunger rod 21 and the piston 50.

[0196] FIG. 12 shows an enlarged illustration of the proximal end of the plunger 20 of FIG. 9. The proximally facing surface 24 of the head 22 of the plunger comprises two circular grooves 27 arranged concentrically around the longitudinal axis A, and the grooves are filled with the injection molding material of the gripping pad 23 during the process of applying the material of the gripping pad 23 to the proximally facing surface 24 of the head 22 of the plunger. Due to the use of these grooves 27, the contact area between the proximally facing surface 24 and the material of the gripping pad 23 can be increased, which leads to better adhesion between the material of the gripping pad 23 and the head 22 of the plunger.

[0197] FIG. 13 shows an enlarged illustration of a bottom view of the piston 50 of the syringe assembly 100 of FIG. 4, and FIG. 14 shows an enlarged illustration of a cross-section of said piston 50, wherein said piston 50 is configured to form a snap-fit ​​connection with the mushroom-shaped tip 25 of the plunger rod 21. In order to ensure a tight fit to the walls of the internal cavity 13 of the barrel 10 of the syringe, said piston 50 has a wave-shaped external geometry. On its lower side 51, the piston 50 contains several projections, not indicated by numbers in the drawing and configured to contact with an axial stop 25C for the piston of the plunger rod 21.

[0198] FIGS. 15-18 show various views of an example of a finger grip 30 according to the present invention of the assemblies 100 and 200 of the syringe of FIGS. 1 and 2, and in FIGS. 15-18, in particular, the curved shape of the wings 31 and 32, the design and arrangement of the grip pads 35 on the distally facing surfaces 33, the central channel 37 and the lateral slot 38 for connecting the finger grip 30 with the proximal end of the barrel 10 of the syringe are evident.

[0199] Similar to the pads 23 for gripping the head of the plunger 20 of the assemblies 100 and 200 of the syringe according to FIGS. 1 and 2, the pads 35 for gripping the finger grip 30 are also made by injection molding. The grip pads 35 are also made in one piece from colored TPE using only one injection point 26, wherein the material of the grip pads 35 is applied directly to the distally facing surfaces 33 of the wings 31, 32. The injection points 26 are also located on the outer edge of the grip pads 35, which also extend almost completely over the corresponding surface 33. As described above, some areas 36 forming parallel and transversely extending strips 36 are not filled or covered with the material of the grip pads 35, but are completely surrounded by the material of the grip pads 35 to achieve a grip with good ergonomics and tactile sensations and reliable contact of the fingers with a reduced risk of slipping of any finger of the user.

[0200] FIG. 19 shows a separate perspective view of the syringe barrel 10 of the syringe assembly 100 of FIG. 1, wherein the internal cavity 13 of said barrel 10 is pre-filled with a hyaluronic acid-based dermal filler. The distal end of said barrel 10 is closed and sealed with a tip cap 40. The proximal end of the syringe barrel 10 contains a flange 12, which can be inserted from the side into a slot 38 of a finger grip 30 to ensure connection of said syringe barrel 10 with a finger grip 30, and accordingly, the finger grip 30 with said barrel 10.

[0201] FIG. 20 shows a longitudinal section of the cylinder 10 of FIG. 19.

[0202] FIG. 21 shows an enlarged illustration of the cap 40 of the tip of FIG. 20. According to the drawing, the barrel 10 of the syringe has a Luer Lock connector 11 at the distal end, wherein the Luer Lock connector has internal threads and a Luer Lock cone 14 surrounding an outlet channel 15 in fluid communication with the internal cavity 13 of the barrel 10 of the syringe.

[0203] The distal end of the syringe barrel 10 is closed and sealed by a tip cap 40 comprising an outer rigid portion 41 engaged with the internal threads of the Luer Lock connector 11 and an inner elastomeric portion 42 inserted into the outer rigid portion 41 to ensure the closure and sealing of the outlet channel 15 of the syringe barrel 10.

[0204] In this example, the maximum outer diameter Dmax of the rigid portion 41 is less than or equal to the outer diameter of the Luer-Lock connector 11 of the syringe barrel 11. This reduces the likelihood of inadvertent snagging or damage to the tip cap 40 and the associated closure and sealing of the pre-filled syringe barrel 10. In particular, the outer wall of the rigid portion is at least partially flush with the outer wall of the Luer-Lock connector.

[0205] All features described herein with respect to one aspect of the present invention may also be implemented separately or in any combination according to any other aspect of the present invention, provided that it is technically feasible.

[0206] List of reference positions on drawings

[0207] 100 - first example of an embodiment of a syringe assembly according to the present invention

[0208] 200 - second example of an embodiment of a syringe assembly according to the present invention

[0209] 10 - syringe barrel

[0210] 11 - Luer Lock connector

[0211] 12 - syringe barrel flange at the proximal end of the syringe barrel

[0212] 13 - Luer Lock Connector Taper

[0213] 15 - exhaust channel

[0214] 20 - an example of an embodiment of a plunger according to the present invention

[0215] 21 - plunger rod

[0216] 22 - plunger head

[0217] 23 - Plunger head gripper

[0218] 24 - proximally facing surface of the plunger head

[0219] 25 - plunger tip at the distal end of the plunger rod

[0220] 25A - Mushroom-shaped plunger rod tip

[0221] 25B - piston intake part

[0222] 25C - Axial stop for piston

[0223] 26 - injection point

[0224] 27 - groove in the proximally facing surface of the plunger head

[0225] 30 - an example of an embodiment of a finger grip according to the present invention

[0226] 31 - Right flange or wing of the finger grip housing

[0227] 32 - Left flange or wing of the finger grip housing

[0228] 33 - distally facing surface of the finger gripper body

[0229] 34 - proximally facing surface of the finger grip body

[0230] 35 - Finger Grip Pad

[0231] 36 - area not filled or covered with injection molding material of the finger grip pad, formed as a strip

[0232] 37 - central channel in the finger grip body

[0233] 38 - slot for final insertion of the proximal flange of the syringe barrel

[0234] 39 - groove in the distally facing surface of the finger gripper body

[0235] 40 - tip cap

[0236] 41 - Hard part of the tip cap (outer part)

[0237] 42 - elastomer part of the tip cap (inner part)

[0238] 50 - piston

[0239] 51 - lower side of piston

[0240] A - longitudinal axis of the syringe barrel

[0241] Dmax - maximum outer diameter of the rigid part of the tip cap.

Claims

1. A finger grip (30) for a syringe assembly for administering a liquid composition, comprising a finger grip body (30) with two flanges (31, 32) extending radially in opposite directions from a central channel (37) in the finger grip body through which a plunger (20) of the syringe assembly can be inserted, wherein each flange (31, 32) functions as a part of the grip and has a finger contact area on which at least one finger of the user can be partially placed during administration to provide support to said finger during administration, wherein each flange (31, 32) comprises a distally facing surface (33) and a proximally facing surface (34), wherein the finger grip (30) comprises a gripping pad (35) attached to the distally facing surface (33) of at least one of the flanges (31, 32) and extending at least partially over said distally facing surface (33), wherein the gripping pad (35) is made by injection molding, characterized in that the lining (35) for gripping on the distally facing surface (33) of the corresponding flange or wing (31, 32) is made in one piece and contains only one injection point (26), wherein the gripping pad (35) is designed in such a way that at least one region (36) not filled or covered with the material of the gripping pad is completely surrounded by the injection molding material, and wherein the area (36) not filled or covered with the grip material comprises one or more stripes or displays the "+" symbol.

2. The finger grip (30) according to claim 1, characterized in that at least one grip pad (35) on the finger grip (30) is made of a thermoplastic elastomer (TPE), in particular a colored thermoplastic elastomer (cTPE).

3. A method for manufacturing a finger grip (30) according to claim 1 or 2, comprising at least the steps of: - manufacturing a finger grip body (30) comprising two flanges (31, 32) extending radially in opposite directions from a central channel (37) in the finger grip body (30) through which a plunger (20) of a syringe assembly (100, 200) can be inserted, each flange (31, 32) serving as a grip portion and having a finger contact area on which at least one user's finger can be partially positioned during insertion to provide support to said finger during insertion, each flange (31, 32) comprising a distally facing surface (33) and a proximally facing surface (34); and - forming a gripping pad (35) by injection molding, wherein the lining (35) for gripping on the distally facing surface (33) of the corresponding flange or wing (31, 32) is made in one piece and contains only one injection point (26), wherein the gripping pad (35) is designed in such a way that at least one region (36) not filled or covered with the material of the gripping pad is completely surrounded by the injection molding material, and wherein the area (36) not filled or covered with the grip material comprises one or more stripes or displays the "+" symbol.

4. A syringe assembly (100, 200) for introducing a liquid composition into the body of a human or animal, comprising at least: a longitudinal cylinder (10) of a syringe having an internal cavity (13) for receiving and storing a liquid composition to be administered; a finger grip (30) connected to the proximal end of said cylinder (10); and a plunger (20) having a plunger rod (21) and a plunger head (22), wherein the plunger rod (21) is located at least partially inside the internal cavity (13) of the cylinder (10) with its distal end (25), characterized in that the finger grip (30) is a finger grip (30) according to paragraph 1 or 2 or a finger grip (30) made by the method according to paragraph 3.

5. The syringe assembly (100, 200) according to claim 4, characterized in that the syringe barrel (10) comprises a Luer Lock connector (11) at its distal end, formed in one piece with the syringe barrel (10), and the syringe assembly (100, 200) also comprises a tip cap (40), and the tip cap (40) covers and seals the distal end of the syringe barrel (10), and the tip cap (40) is a two-component tip cap (40) comprising a rigid part (41) and an elastomeric part (42), and the maximum outer diameter (Dmax) of the rigid part (41) is less than the outer diameter of the Luer Lock connector (11) of the syringe barrel or equal to it.

6. A kit for administering a liquid composition into the body of a human or animal, comprising parts of a syringe assembly (100, 200) according to claim 4, wherein the kit comprises at least: a longitudinal cylinder (10) of a syringe having an internal cavity (13) for receiving and storing a liquid composition to be administered; a finger grip (30) adapted to be connected to the proximal end of said cylinder (10); and a plunger (20) having a plunger rod (21) and a plunger head (22), wherein the plunger rod (21) is designed with the possibility of being placed at least partially within the internal cavity (13) of said cylinder (10) with its distal end, wherein the parts of the set are designed with the possibility of assembly to obtain a syringe unit (100, 200) according to paragraph 4, characterized in that the finger grip (30) is a finger grip (30) according to paragraph 1 or 2 or a finger grip (30) made by the method according to paragraph 3.

7. The use of the syringe assembly (100, 200) according to claim 4 in the field of cosmetic or therapeutic use, wherein an effective volume of a liquid composition is administered to the patient.

8. The use of a syringe assembly (100, 200) according to claim 7, wherein the syringe assembly (100, 200) is used to replace or fill biological tissue or increase the volume of biological tissue.

9. The use of a syringe assembly (100, 200) according to claim 7 or 8, wherein the effective volume of the liquid composition that is administered to the patient is an effective volume of the dermal filler composition.

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