Syringe, injector and injection device for injecting highly viscous medium

Abstract

To provide a syringe (12) for injector for injecting a highly viscous medium.SOLUTION: A syringe (12) includes a distal end (18) and a proximal end (20). The syringe (12) has a hollow cylindrical shape and forms a chamber for housing a highly viscous medium. The proximal end (20) has an aperture through which a plunger rod unit (14) can be inserted into the chamber. At the distal end (18) is formed a luer lock connector (22), the luer lock connector (22) including an outer cone (40) comprising a relatively wide aperture (42) for supplying the highly viscous medium and a sleeve-shaped part (44) comprising a female thread (46). The syringe (12) has an NPO minimum resistance exceeding 90 N.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a syringe, injector and injection device for injecting a highly viscous medium. In particular, these syringes, injectors and injection devices can be used for injecting or administering highly viscous medicinal media. [Background technology]

[0002] Syringes are used, for example, in the medical and cosmetic fields, to inject a medium contained in the syringe into a patient's body. For example, in the context of cosmetic treatment of a patient's skin, a dermal filler is injected, for example, below the surface of the patient's skin. In cosmetic applications, a highly viscous medium is often used. The medium contained in the syringe may include a wide variety of forms of fluids, pastes or liquid substances as well as mixtures.

[0003] In order to keep the skin puncture required for injection and the associated pain to the patient as small as possible, needles are preferably provided with a very small cannula size ("gauge"), this being particularly true for use on the patient's face.

[0004] The combination of the smallest possible cannula diameter and a highly viscous medium to be injected places a high load on the injector or syringe. Particularly high pressures in the injector can lead to mechanical failure of the injection unit. However, since mechanical failure of the injector must be avoided, previously known injectors limit the possibility of using needles with small cannula diameters, which also entails the above-mentioned disadvantages for the patient. Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore an object of the present invention to overcome the drawbacks of the prior art, in particular to provide a syringe, an injector and an injection device which allow the use of needles with small cannula diameters for injecting highly viscous media. [Means for solving the problem]

[0006] This problem is solved by a syringe, an injector and an injection device according to the respective independent patent claims. Refinements and embodiments of the syringe, an injector and an injection device are set out in the dependent claims and the following description.

[0007] One aspect of the invention relates to a syringe for an injector for injecting or administering a high-viscosity medium. In one embodiment, the high-viscosity medium is characterized by a storage modulus G' of at least 30 Pa and at most 150 Pa, in particular at least 50 Pa and at most 100 Pa, or at least 70 and at most 90 Pa. The loss modulus tan δ may be 0.2 to 0.8, in particular 0.3 to 0.6 or 0.4 to 0.5. This may for example be a hyaluronic acid filler. The viscosity may be measured at 25° C. and a pressure of 1013.25 hPa using a plate-plate measuring system (for example a rheometer MCR302 from Anton Paar), in particular with a frequency of 1 Hz. The measurement may for example be carried out according to the method described in ISO standard 6721-10-2015-09. The syringe has a distal end and a proximal end. The syringe is hollow cylindrical and forms a chamber for receiving the high-viscosity medium. The proximal end has an opening through which a plunger rod unit is insertable or is inserted into the chamber, the plunger rod unit being movable in the chamber in the direction of the chamber longitudinal axis and being slidably guided within the syringe.

[0008] A luer lock connector is formed at the distal end of the syringe, which has an outer cone with a relatively wide opening for feeding the highly viscous medium and a sleeve-like part with an internal thread. The luer lock connector forms part of a luer lock coupling system and is designed to cooperate with a luer lock connector counterpart formed on the needle unit. The outer cone can also be described as a conical nozzle that protrudes beyond the distal end of the syringe and allows the highly viscous medium to be drawn out of the chamber. The outer cone also forms part of the luer lock coupling system and also cooperates with a complementary counterpart on the needle unit. In the luer lock coupling system, the outer cone and the sleeve-like part surrounding it are arranged coaxially with one another. The luer lock connector of the syringe can be formed and dimensioned in particular within the framework of ISO standard 80369-7:2016-12-01. This allows the syringe according to the invention to be used with a number of different needle units standardized in the field of luer lock coupling.

[0009] The syringe according to the invention has an NPO minimum resistance of more than 90N. Preferably, the syringe may have an NPO minimum resistance of more than 95N, preferably more than 100N, more preferably more than 103N. In particular, the syringe may have an NPO minimum resistance of 90N-105N, preferably 95N-103.5N, preferably 98N-102N. NPO stands for "Needle Pop Off" and refers to the sudden disengagement or detachment of the needle unit from the syringe, in particular the needle unit connected to the syringe via a luer lock connection. The needle unit starts to rotate under high pressure (triggered by the application of force to the syringe via the plunger rod unit) and starts to come off the syringe at high speed, i.e. the inner cone of the needle unit, which is complementary to the outer cone of the syringe, comes off.

[0010] The NPO minimum resistance (minimum "needle penetration" resistance) is the threshold force that is introduced into the syringe and applied to the plunger rod unit in operative connection with the syringe within the framework of the test method described below. The NPO minimum resistance is defined as the threshold below which no more than 1.8% of the syringes tested experience a "needle penetration". At least 56 measurements of syringes of the same type and construction are required to obtain meaningful results for the NPO minimum resistance.

[0011] The test method for determining the NPO resistance, in particular the minimum NPO resistance and the average NPO resistance, assumes that the syringe to be tested is vertically positioned in a test machine and held in the region of the proximal end of the syringe. The test machine used is a universal test machine of the company "TesT" model "TesT 106.2kN". This or a comparable universal test machine can be used for this test method.

[0012] The syringe to be tested is connected to a needle unit via a luer lock connector, and the needle unit is screwed onto the distal end of the syringe with a torque of 12 Ncm to form a luer lock connection with a luer lock connector counterpart. In particular, the test method is preferably carried out using a needle unit "TSK STERiJECT Hypodermic Needle" Ref.: PRC-300131, 30G x 1 / 2 or a needle unit comparable thereto. The needle unit used in this test method has an inner cone and two pointed ends arranged on the outer periphery of the needle base of the needle unit as a luer lock connector counterpart. The needle unit used in this test method has a cannula or hollow needle with a diameter of 30G and a length of 13 mm (30G x 1 / 2). The cannula must be flattened with a hammer and closed for testing before carrying out the test method. For this test method, the needle unit can be threaded onto the syringe and then the high viscosity medium can be filled into the chamber to form a dry luer lock connection. This test method can be performed with non-steam sterilized components (syringe, needle unit, plunger rod unit).

[0013] For the inventive test method, a high-viscosity medium may be selected having a storage modulus G' of about 84.5 Pa and a loss factor tan δ of about 0.48. The viscosity may be measured at 25° C. and a pressure of 1013.25 hPa using a plate-plate measuring system (e.g. rheometer MCR302 from Anton Paar), in particular at a frequency of 1 Hz. The measurement may be carried out, for example, by the method described in ISO standard 6721-10-2015-09. The syringe to be tested is completely filled with the high-viscosity medium as specified. Furthermore, the plunger rod unit is brought into the syringe at the start of the test method and is in operative connection with the syringe, while the syringe and the plunger rod unit are still in the starting position, i.e. in the inoperative position, at the start of the test method. A standard plunger rod unit may be used for the inventive test method, which is provided for each syringe to be tested. For example, in the case of a syringe with an interior diameter of 5 mm, a standard plunger of type FM257 (eg, from the manufacturer Daetwyler) may be used.

[0014] In this test method, a force is applied perpendicularly to the proximal end of the plunger rod unit via the test plunger of the test machine. The test plunger is moved towards the distal end of the syringe with a constant test speed of 12.6 mm / min, while the force acting on the plunger rod unit is continuously increased up to a maximum of 420 N. The test plunger is moved a distance of up to 15 mm during the test. The applied force is detected by a force sensor with a sampling rate of 200 Hz. The test plunger continues to be moved or the applied force is increased until an impermeability ("leak") and / or NPO occurs or a maximum force of 420 N is reached. If the measured force suddenly decreases by at least 30%, the test is stopped, i.e. an impermeability ("leak") and / or NPO is found. The applied force at the time of impermeability and / or NPO occurrence is recorded and associated with the information whether impermeability and / or NPO occurs at this force. In this case, the above-mentioned minimum NPO resistance and average NPO resistance can be determined from the recorded measurement results. The impermeability ("leak") investigated here is the impermeability between the syringe and the needle unit that occurs due to the applied force and the resulting pressure. In other words, the force that causes the undesirable outflow of the high-viscosity medium in the region of the luer lock connection between the syringe and the needle unit can be determined.

[0015] Mechanical failures to be avoided may occur due to in particular NPO, tightness ("leakage") between the syringe components coupled together and / or syringe breakage. The inventors of the present invention have realized that for use with high viscosity media and small cannula sizes of at least 31 G, a syringe with the above-mentioned NPO minimum resistance is advantageous. A relatively small needle or cannula diameter (e.g., greater than 30 G) means less pain for the patient than a relatively large needle or cannula diameter (e.g., a diameter of 27 G used traditionally with high viscosity media), but at the same time, a higher force must be applied to deliver the high viscosity media than with a relatively large needle or cannula diameter. The above-mentioned values ​​according to the present invention for the NPO minimum resistance take into account the finding that, when used properly, a male user can actuate the syringe or injection device with an average maximum force (maximum finger force) of 95 N. When used properly, a female user can actuate the syringe or injection device with an average maximum force (maximum finger force) of 64 N. Thus, the above-mentioned NPO minimum resistance constitutes an optimal design of a syringe structure that is not over-sized while still ensuring reliable injection of highly viscous media with very thin cannulas.

[0016] In one refinement, the syringe may have an average NPO resistance of at least 100N, preferably at least 105N, preferably at least 110N, more preferably at least 115N, even more preferably at least 117N. In particular, the average NPO resistance may be between 100N and 120N, preferably between 105N and 120N, preferably between 110N and 120N, more preferably between 115N and 117N.

[0017] The average NPO resistance represents the average force that must be applied to the plunger rod unit in operative connection with the syringe, as provided in the test method described above, to produce needle penetration. Again, at least 56 measurements of syringes of the same type and construction are required to obtain meaningful results for the average NPO resistance.

[0018] In one embodiment, the syringe may have a minimum resistance to leakage of at least 100 N. Preferably, the syringe may have a minimum resistance to leakage of more than 105 N, preferably more than 117.5 N, more preferably more than 125 N. In particular, the syringe may have a minimum resistance to leakage of 100 N to 130 N, preferably 105 N to 120 N, preferably 110 N to 115 N.

[0019] In one refinement, the syringe may have an average leak resistance of at least 115 N, preferably at least 120 N, preferably at least 123 N, more preferably at least 125 N, even more preferably at least 127 N. In particular, the average leak resistance may be between 110 N and 135 N, preferably between 115 N and 130 N, preferably between 120 N and 130 N, more preferably between 125 N and 130 N.

[0020] The minimum leak resistance (minimum impermeability resistance) is a threshold force that is produced in a syringe within the framework of the above-mentioned test method and that is applied to the plunger rod unit in operative connection with the syringe. The minimum leak resistance is defined by the threshold below which impermeability occurs in less than 1.8% of the syringes tested. At least 56 measurements of syringes of the same type and construction are required to obtain a meaningful result for the minimum leak resistance.

[0021] Furthermore, the average leak resistance indicates the average force that must be applied to the plunger rod unit in operative connection with the syringe, as produced in the above-mentioned test method, in order to produce a tight seal. Again, at least 56 measurements of syringes of the same type and construction are required to obtain meaningful results regarding the average leak resistance.

[0022] In one embodiment, the female thread of the luer lock connector may have an internal diameter of up to 7.15 mm or up to 7.12 mm. The internal diameter may preferably be at least 7.05 mm or at least 7.08 mm. In a preferred embodiment, the internal diameter is between 7.05 mm and 7.15 mm, preferably between 7.08 mm and 7.12 mm, preferably at most 7.1 mm. This internal diameter represents the smallest internal diameter of the sleeve-like end, i.e. measured from the thread ridge of the female thread to the opposite thread ridge. An internal diameter with this dimension can have a positive effect on a sufficiently tight coupling between the syringe and the needle unit coupled to the syringe, and thus can have an advantageous effect on the adjustment of the NPO minimum resistance as well as the average NPO resistance. This also applies to the leakage minimum resistance and the average leakage resistance.

[0023] In one embodiment of the syringe, the female thread may have a width at the ridge of the thread cross section of at least 0.44 mm or at least 0.46 mm. Preferably, this width is at most 0.52 mm or at most 0.50 mm. In a preferred embodiment, the width may be between 0.44 mm and 0.52 mm, preferably between 0.46 mm and 0.50 mm, preferably 0.48 mm.

[0024] Additionally or alternatively, the female thread may have a width at the root of the thread cross section of at least 0.85 mm or at least 0.875 mm. Preferably, this width is at most 0.95 mm or at most 0.925 mm. In preferred embodiments, the width may be between 0.85 mm and 0.95 mm, preferably between 0.875 mm and 0.925 mm, preferably 0.9 mm.

[0025] The female thread may have an angle of 22.5° to 27.5°, in particular an angle of 24° to 26° or about 25°, on both sides of the thread cross section, which angle may represent the angle formed between a line perpendicular to the longitudinal axis of the syringe and intersecting the thread cross section, and the side of the thread cross section.

[0026] By forming the thread profile parameters according to the above-mentioned dimensions, the contact surface of the thread connection, i.e. between the female thread of the syringe and the complementary male thread of the attached needle unit, can be adapted. This can improve the luer lock connection with the attached needle unit and have a favorable effect on the adjustment of the NPO minimum resistance as well as the average NPO resistance. This also applies to the leakage minimum resistance and the average leakage resistance.

[0027] In one refinement, the distal end face of the outer cone, with its relatively wide opening, where the outer cone ends, may protrude beyond the distal collar of the sleeve-like part by a distance of at least 2.1 mm or at least 2.2 mm. In one embodiment, said distance is at most 2.5 mm or at most 2.4 mm. In one preferred embodiment, the distal end face of the outer cone protrudes beyond the distal collar of the sleeve-like part by a distance of 2.1 mm to 2.5 mm, preferably 2.2 mm to 2.4 mm, preferably 2.3 mm. This structural adaptation can also have an advantageous effect on the adjustment of the NPO minimum resistance as well as the average NPO resistance. This applies equally to the leakage minimum resistance and the average leakage resistance.

[0028] In one embodiment, the syringe may have at the proximal end an inner circumferential surface with an inclined surface, the inclined surface tapering the inner circumferential surface as viewed in the direction from the proximal end towards the distal end. In other words, the inner circumferential surface may be constricted in the region of the inclined surface as viewed in the direction towards the distal end, and extend in a conical shape. The inclined surface may facilitate the insertion of the plunger rod unit, or more precisely the plunger, into the chamber of the syringe. The inclined surface may have a length of at least 1.2 mm or at least 1.4 mm as viewed in the direction of the longitudinal axis of the syringe. In some embodiments, said length is at most 1.8 mm or at most 1.6 mm. In preferred embodiments, said length is between 1.2 mm and 1.8 mm, preferably between 1.4 mm and 1.6 mm, preferably about 1.5 mm. Additionally or alternatively thereto, the inclined surface may form an angle with the longitudinal axis of at least 13°, preferably at least 14°, preferably at least 15°. By forming the beveled surface dimensioned in this way, the overall length of the syringe can be reduced compared to known syringes. This can have a beneficial effect on the ergonomics of the syringe or on its handling by the user. Nevertheless, the beveled surface dimensioned in this way can ensure sufficient stability and sealing of the syringe (so-called Container Closure Integrity, CCI). Thus, for example, it can be assumed that in a fully filled, non-activated syringe, there is a distance of at least 9 mm to a maximum of 10 mm, or about 9.5 mm, between the proximal end of the syringe and the proximal end of the plunger of the plunger rod unit.

[0029] The syringe may have a maximum overall length of 80 mm in one embodiment and a maximum chamber diameter of 5 mm, in which case a volume of at least 1 ml can be accommodated in the syringe. More precisely, a volume of at least 1 ml can be accommodated in the chamber and in the chamber part formed by the outer cone, which is adjacent to the chamber. The overall length can be measured from the end face defining the proximal end of the syringe to the end face defining the distal end of the syringe, i.e. the end face of the outer cone. The chamber diameter can be constant over the entire length of the chamber. For example, a total volume of 1073 ml can be accommodated in the chamber and in the chamber part, which allows for a 2% overfill in the chamber and a 1 mm long air bubble entrapment. It should be pointed out that the volume that can be accommodated is not equated with the total volume formed by the chamber and the chamber part as a whole. In addition to the volume of the medium to be accommodated and the above-mentioned tolerances for overfill and air bubbles, the chamber must also be able to accommodate and stably support a portion of the plunger rod unit already in the inactive position. For this purpose, the plunger of the plunger rod unit must already be accommodated in the syringe in the inactivated position, far enough away from the proximal end of the syringe: for example, there may be a distance of 9.5 mm between the proximal end of the syringe and the proximal end of the plunger of the plunger rod unit.

[0030] The syringe may be suitably configured and dimensioned in accordance with ISO standard 11040-6:2012-04-01.

[0031] The syringe may in one alternative embodiment have a maximum overall length of 60mm and a maximum interior diameter of 4.65mm, allowing a combined volume within the chamber and chamber portions of at least 0.5ml.

[0032] The syringe may in one alternative embodiment have a maximum overall length of 71 mm and a maximum interior diameter of 5 mm, allowing a combined volume within the chamber and chamber portions of at least 0.8 ml.

[0033] The syringe may in one alternative embodiment have a maximum overall length of 95mm and a maximum interior diameter of 6.45mm, allowing a combined volume within the chamber and chamber portions of at least 2.25ml.

[0034] The syringe may in one alternative embodiment have a maximum overall length of 117 mm and a maximum interior diameter of 6.45 mm, allowing a combined volume of at least 2.8 ml within the chamber and chamber portions.

[0035] The syringe may in one alternative embodiment have a maximum overall length of 56 mm and a maximum interior diameter of 12.2 mm, allowing a combined volume within the chamber and chamber portions of at least 2.8 ml.

[0036] The syringe may, in one alternative embodiment, have a maximum overall length of 58 mm and a maximum interior diameter of 12.2 mm, allowing a combined volume within the chamber and chamber portions of at least 3.0 ml.

[0037] The syringe may in one alternative embodiment have a maximum overall length of 115mm and a maximum interior diameter of 8.75mm, allowing a combined volume of at least 5ml within the chamber and chamber portions.

[0038] The above values ​​may be maximum or exact dimensions. A small internal diameter has a positive effect on the administration of highly viscous liquids by applying finger pressure to the syringe or injection device. At the same time, however, care must be taken not to select an excessively large total length of the syringe, which also determines the total length of the plunger rod unit used with it, in order to ensure maneuverability. The above-mentioned embodiments constitute embodiments that show advantageous combinations of total length and internal diameter for various syringe volumes, for example.

[0039] In one refinement, the syringe may have a wall thickness, at least in the region of the chamber, of at least 1.7 mm, preferably at least 1.8 mm, preferably at least 2.0 mm, more preferably at least 2.2 mm. Forming such a wall thickness can positively influence the shape stability of the syringe during use, thereby reducing mechanical failure of the syringe. The values ​​shown represent an optimized geometry with respect to the ratio between the inner diameter and the outer diameter.

[0040] The syringe may have, for example in the region of the chamber, an outer diameter of 5 mm to 15 mm, in particular 7.5 mm to 12.5 mm, or 8.4 mm to 10 mm, in particular about 9.4 mm.

[0041] The syringe may be configured to have an extrusion force of less than 40 N when the standard plunger is moved through the chamber towards the distal end at 10 mm / min. The syringe may be configured to have an extrusion force of less than 75 N when the standard plunger is moved through the chamber towards the distal end at 50 mm / min. The syringe may be configured to have an extrusion force of less than 100 N when the standard plunger is moved through the chamber towards the distal end at 100 mm / min. The above values ​​relate to the supply of a highly viscous medium having a storage modulus G' of about 84.5 Pa and a loss factor tan δ of about 0.48. The viscosity can be measured at 25° C. and a pressure of 1013.25 hPa using a plate-plate measuring system (e.g. rheometer MCR302 from Anton Paar), in particular with a frequency of 1 Hz. The measurement can be carried out, for example, according to the method described in ISO standard 6721-10-2015-09. The ejection force represents the force with which the medium flows out of the cannula of the needle unit coupled to the syringe. Highly viscous media usually require a higher ejection force than low-viscosity media. The above values ​​apply to a test unit with a needle unit having a cannula with a thickness of 30 G and a length of 13 mm, i.e. the needle unit 30G x 1 / 2, in particular the needle unit "TSK HYPODERMIC NEEDLE", Ref.: HPC-30013l-320, 30G x 1 / 2. In this test method, the cannula is open, so that the highly viscous medium can flow out of the cannula. The needle unit has a thread (unlike a needle unit with a pointed end) as a luer lock connector counterpart. For highly viscous media, a syringe with such a relatively small ejection force requires less force to be applied by the user, allowing improved metering accuracy. This means that such a syringe allows the use of needle units with smaller cannula thicknesses, i.e. 30G or more, despite the use of highly viscous media.

[0042] In one embodiment, the syringe may be made of a plastic material having a suitable elastic modulus of 2800 MPa to 3300 MPa, in particular 2900 MPa to 3200 MPa (1 mm / min, ISO 527 parts 1 and 2). The plastic material may have a tensile strength in the range of 58 MPa to 65 MPa, in particular 60 MPa to 63 MPa (5 mm / min, ISO 527 parts 1 and 2). The plastic material may have a water absorption of less than 0.01% (ISO 62). Furthermore, the plastic material may have a modulus of elasticity of 180 to 195 N / mm 2 (30 seconds value at a load of 961 N based on ISO2039 Part 1). The plastic material may have a hot shape endurance temperature of 120 to 180 °C (HDT / B 0.45 MPa, ISO75 Parts 1 and 2). The linear thermal expansion coefficient of the plastic material is 6.0 x 10 -4 K -1 (ISO 11359 Parts 1 and 2). The elongation at break of the plastic material may be in the range of 2.5-2.7% (ISO 527 Parts 1 and 2). The impact strength of the plastic material may be about 15 kJ / m 2 (ISO179 / 1eU) and / or the notched impact strength may be 1.6 kJ / m 2 ~1.8kJ / m 2 (ISO179 / 1eA).

[0043] The syringe, in one refinement, may have a flange at its proximal end, which may form or may be provided with a grip to support the index and middle fingers of a user when using the syringe.

[0044] Another aspect of the invention relates to a syringe for injecting a highly viscous medium, comprising a syringe and a plunger rod unit of the above-mentioned type. The plunger rod unit comprises a plunger rod and a plunger attached to the distal end of the plunger rod. The plunger is accommodated in a chamber through an opening formed in the proximal end of the syringe and is movably guided in the chamber. The plunger may have, for example, three sealing lips.

[0045] The syringe may have a high-viscosity medium contained in the syringe chamber. In one embodiment, the high-viscosity medium is characterized by a storage modulus G' of at least 30 Pa and at most 150 Pa, in particular at least 50 Pa and at most 100 Pa, or at least 70 and at most 90 Pa. The loss modulus tan δ may be 0.2 to 0.8, in particular 0.3 to 0.6 or 0.4 to 0.5. The viscosity may be measured using a plate-plate measuring system at 25° C. and a pressure of 1013.25 hPa, in particular with a frequency of 1 Hz (e.g., a rheometer MCR302 from Anton Paar). The measurement may be carried out, for example, according to the method described in ISO standard 6721-10-2015-09. For example, the syringe may have a hyaluronic acid filler and / or another cosmetic composition contained in the syringe chamber.

[0046] The syringe may have a grip length of 6 cm to 12 cm, in particular 7.5 cm to 8 cm. The grip length refers to the length between the proximal end of the syringe and the proximal end of the plunger rod unit. The plunger rod unit may be provided with a grip at its proximal end.

[0047] Another aspect of the invention relates to an injection device for injecting highly viscous media, comprising a syringe and a needle unit of the above-mentioned type. The needle unit comprises a needle hub and a cannula, where the needle hub comprises a luer lock connector complementary to the luer lock connector of the syringe to form a luer lock connection between the syringe and the needle unit. That is to say, the needle hub comprises an inner cone complementary to the outer cone of the syringe and preferably an external thread complementary to the internal thread of the syringe. As an alternative to the external thread, the needle hub may comprise two points arranged on the outer periphery of the needle hub.

[0048] The needle unit may have a cannula with a gauge of at least 30 G, preferably at least 31 G, preferably at least 32 G, preferably at least 33 G, more preferably at least 34 G, even more preferably at least 35 G. The cannula may have a length of at least 10 mm, preferably at least 11 mm, preferably at least 12 mm, more preferably at least 13 mm. Alternatively, the cannula may have a length of 25 mm or more.

[0049] The hub of the needle unit may have an inner cone with a length along the longitudinal axis of the needle unit of between 3mm and 7mm, preferably between 5.5mm and 6.5mm, preferably about 6.1mm.

[0050] In particular, the injection device may have a needle unit "TSK HYPODERMIC NEEDLE" Ref.: HPC-300131-320, 30G×1 / 2 or a comparable needle unit.

[0051] Alternatively, the injection device may have a needle unit "TSK STERiJECT Hypodermic Needle" Ref.: PRC-300131, 30G×1 / 2 or a comparable needle unit.

[0052] In one embodiment, the syringe may be formed from a plastic material including or consisting of cycloolefin copolymer (COC) and / or cycloolefin polymer (COP).

[0053] In one refinement, the plastic material may comprise one or more additives, in which case the additives may suitably be colorants.

[0054] Although some aspects and features are described above and below only with respect to syringes, these aspects and features apply correspondingly with respect to injectors and / or injection devices, and vice versa.

[0055] The invention also relates to a therapeutic or cosmetic method comprising administering a highly viscous cosmetic formulation using a syringe as described herein, an injector as described herein or an injection device as described herein. In one embodiment, the highly viscous cosmetic formulation is characterized by a storage modulus G' of at least 30 Pa and at most 150 Pa, in particular at least 50 Pa and at most 100 Pa, or at least 70 and at most 90 Pa. The loss modulus tan δ may be between 0.2 and 0.8, in particular between 0.3 and 0.6 or between 0.4 and 0.5. The viscosity may be measured using a plate-plate measuring system at 25° C. and a pressure of 1013.25 hPa, in particular with a frequency of 1 Hz (e.g. a rheometer MCR302 from Anton Paar). The measurement may be carried out, for example, according to the method described in the ISO standard 6721-10-2015-09. The administration may comprise an injection of the cosmetic formulation into the organism to be treated. Preferably, the formulation is administered into an administration site in the human body. The administration may be by subcutaneous injection. The site of administration may be on the face of a person or on any part of a person. [Brief description of the drawings]

[0056] In the following, embodiments of the invention will be explained in more detail with reference to the accompanying schematic drawings. [Figure 1] 1A-1D are various perspective views of an injection device according to one embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional view showing a luer lock connector of one embodiment of a syringe. [Diagram 3] FIG. 3 is a detailed view of the cross section of the thread shown in FIG. 2. [Figure 4] FIG. 2 is a cross-sectional view showing one embodiment of a syringe with a plunger rod unit housed therein. [Diagram 5] FIG. 5 is a detailed view of the inclined surface of the syringe shown in FIG. [Figure 6] 1 is a diagram showing NPO and leakage test results for a syringe according to the present invention. [Figure 7] 1 is a graph showing test results regarding ejection force of a syringe according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] The same reference numerals in the figures indicate the same or similar parts.

[0058] 1 shows various exploded and assembled perspective views of an injection device 10 according to one embodiment of the present invention. The injection device 10 includes a syringe 12, a plunger rod unit 14 and a needle unit 16.

[0059] The elongated syringe 12 is hollow and cylindrical and defines a chamber for containing a medium, particularly a high viscosity medium. The syringe 12 has a distal end 18 and a proximal end 20. The proximal end 20 has an opening through which the plunger rod unit 14 can be inserted into the chamber (see the right-hand view of FIG. 1). The distal end 18 of the syringe 12 is formed with a luer lock connector 22, which will be described in more detail with reference to FIG. 2. The proximal end 20 of the syringe 12 includes a flange 24 that serves as a grip for supporting the index and middle fingers of a user when the syringe 12 is in use.

[0060] The plunger rod unit 14 comprises a plunger rod 26 and a plunger 28, which in this embodiment is made of an elastic material and has three sealing lips. The plunger 28 is attached to the distal end of the plunger rod 26 and is slidably guided within the chamber of the syringe 12 over the inner circumferential surface thereof and may be movable in the direction of the longitudinal axis of the chamber. The plunger rod unit 14 comprises a grip 30 at its proximal end, through which the user's thumb can apply force to the injection device 10.

[0061] The needle unit 16 comprises a hub 32 and a cannula 34 in the form of a hollow needle. In the embodiment shown, the cannula 34 has a thickness of at least 30G and a length of 13 mm. However, cannulas with different dimensions may be used. The hub 32 comprises a luer lock connector mating element 36 which, together with the luer lock connector 22 of the syringe 12, can form a tight luer lock connection, so that the syringe 12 can be connected to the needle unit 16. The luer lock connector mating element 36, or more precisely the hub 32, has an inner cone in the embodiment shown and two points formed on the outer circumferential surface of the proximal end of the hub 32. It is self-evident that in alternative embodiments the hub can comprise an external thread or an external thread portion instead of the points. With such an embodiment with an external thread, a more secure luer lock connection can be achieved.

[0062] In order to keep the syringe 12 closed, for example during transport, the syringe 12 can be closed in the region of the luer lock connector 22 by a lid 38, shown in Fig. 1, which is formed complementary to the luer lock connector 22 of the syringe 12. After the lid 38 has been removed from the syringe 12, the needle unit 16 is coupled to the syringe 12.

[0063] In an assembled state in which the syringe 12, plunger rod unit 14, and needle unit 16 are structurally and operatively coupled to one another, the injection device 10 may be brought from an inactivated position to an activated position by moving the plunger 28 within the chamber from the proximal end 20 toward the distal end 18, such that a highly viscous medium contained within the chamber, such as hyaluronic acid, may be injected through the cannula 34 and beneath the surface of the patient's skin.

[0064] Syringe 12, in the illustrated embodiment, is made from cycloolefin polymer (COP) or cycloolefin copolymer (COC).

[0065] In Fig. 2, an enlarged cross-sectional view of the luer lock connector 22 of the syringe 12 is shown. The luer lock connector 22 has an outer cone 40 with a relatively wide opening 42 for feeding the highly viscous medium contained in the chamber. As can be seen in Figs. 1 and 2, the outer cone 40 protrudes beyond the distal end of the syringe 12 as a conically shaped nozzle. The luer lock connector 22 further has a sleeve-like portion 44 with an internal thread 46. The outer cone 40 is surrounded by the sleeve-like portion 44, where the outer cone 40 and the sleeve-like portion 44 are arranged coaxially with each other.

[0066] The female thread 46 has a minimum internal diameter I1, measured from the thread ridge 50 to the opposing thread ridge 50' of the female thread 46, of 7.1 mm. The maximum internal diameter I2, measured from the thread valley 54 to the opposing thread valley 54' of the female thread 46, is 8.0 mm in the embodiment shown. H is 10.0 mm. The sleeve-like portion 44 thus has a wall thickness of 1 mm.

[0067] As can be seen from the detailed view of the thread cross section of the female thread 46 shown in FIG. 2 and particularly in FIG. 3, the female thread 46 has a width B of 0.48 mm at the ridge 50 of the thread cross section. K Furthermore, the female thread 46 has a width B of 0.9 mm at the valley 54 of the thread cross section.G The female thread has angles α and β of 25° on either side of the thread profile. The thread profile formed with these dimensions serves to optimally secure the common contact surface with the complementary male thread of the attached needle unit. This can contribute to the precise adjustment of the NPO minimum resistance, average NPO resistance, leakage minimum resistance and average leakage resistance.

[0068] The outer cone 40 has a distal end face 56 in which a relatively wide opening 42 is formed. The distal end face 56 projects beyond the distal collar 58 of the sleeve-like portion 44 by a distance A of 2.3 mm as viewed in the direction of the longitudinal axis L of the syringe 12. Furthermore, the distal end face 56 of the outer cone 40 is spaced a distance B of 3.1 mm from the underside of the first complete thread profile opposite the end face 56. The outer cone 40 has a total conical length C of 8.9 mm in the illustrated embodiment.

[0069] In particular, the parameter B of the thread profile shown in Fig. 3 K ,B G , α and β, the minimum inner diameter I1 and / or the distance A may be provided with the above dimensions for multiple syringes of different volumes, thereby achieving optimal values ​​for the NPO minimum resistance, average NPO resistance, minimum leakage resistance and average leakage resistance of the syringe 12.

[0070] 4 shows a cross-sectional view of a syringe 12 with a plunger rod unit 14 housed therein, which is not shown in its entirety for reasons of clarity. The syringe 12 of the illustrated embodiment has an overall length L of 80.0 mm. SK This total length L SK is composed of the length of the part of the syringe that forms the chamber and the total cone length C of the outer cone 40. K In the illustrated example, the inner space of the syringe 12 and the space in the subsequent chamber formed by the outer cone 40 are 5 mm in total. 3A medium, in particular a highly viscous medium, having a volume V of 1 ml can be accommodated. This accommodable volume V results from the consideration and the resulting constructional measures that the syringe 12 should deliver a highly viscous medium in a volume of 1 ml. Furthermore, the chamber must allow for an overfill of 2% and an air bubble entrapment of 1 mm in length (see length s). In addition to the volume of the medium to be accommodated and the above-mentioned tolerances for overfill and air bubbles, the chamber must also be able to accommodate and stably support a part of the plunger rod unit already in the inoperative position. For this purpose, the proximal end of the plunger 28 of the plunger rod unit 14 is preferably already arranged at a distance u of 9.5 mm from the proximal end of the syringe 12 in the inoperative position. Furthermore, in this inoperative position, the third (proximal) sealing lip of the plunger 28 of the plunger rod unit 14 is also arranged at a distance o of 9.5 mm from the inclined surface 60 of the syringe 12. The plunger 28 has a length t of, for example, 6.9 mm.

[0071] The angled surface 60 is formed on the inner periphery of the proximal end 20 of the syringe 12. The angled surface 60 tapers the inner periphery of the syringe 12 when viewed in a direction from the proximal end 20 toward the distal end 18.

[0072] 5 shows the inclined surface 60 on an enlarged scale. The inclined surface 60 has a length w of 1.5 mm in the direction of the longitudinal axis L of the syringe 12 and forms an angle γ of 15° with the longitudinal axis L. In the transition region of the inclined surface 60 to the proximal end of the syringe 12, a radius R of 0.5 mm is provided.

[0073] The syringe 12 of the illustrated embodiment has a wall thickness of 2.2 mm in the region of the chamber, which provides sufficient shape stability against breakage of the syringe.

[0074] In Fig. 6, a diagram is shown illustrating the test results for a syringe according to the invention, showing the different measured resistance of the syringe to NPO and leakage. The underlying tests were carried out with the syringe 12 shown in Figs. 1-5. The x-axis of the diagram shows the different measurements of the illustrated measurement series (56 individual measurements). The y-axis shows the measured force exerted on the syringe at the time of failure of the syringe due to NPO or leakage.

[0075] For the test method, the syringe 12 to be tested was placed vertically in a universal testing machine of the type "TesT 106.2 kN" of the company "TesT" and held in the region of the proximal end of the syringe 12. Before the start of the test, the syringe 12 to be tested was connected via a luer lock connector 22 to a needle unit "TSK STERiJECT Hypodermic Needle" Ref.: PRC-300131, 30G x 1 / 2, which has an inner cone as a luer lock connector counterpart and two pointed ends arranged on the outer periphery of the needle base of the needle unit to form a luer lock connection. The luer lock connector 22 of the syringe 12 was screwed with a torque of 12 Ncm to the luer lock connector counterpart of the needle unit. The cannula of the needle unit, which has a diameter of 30G and a length of 13 mm (30G x 1 / 2), was flattened by a hammer and closed accordingly before the test method was carried out. For this test method, the needle unit was screwed onto the syringe and then the high-viscosity medium was filled into the chamber, thus forming a dry Luer lock connection. The test method was carried out with components that were not steam sterilized (syringe, needle unit, plunger rod unit). A high-viscosity placebo medium was used for the test method. This high-viscosity placebo medium had a storage modulus G' of about 84.5 Pa and a loss modulus tan δ of about 0.48. The viscosity was measured at 25° C. and a pressure of 1013.25 hPa using a plate-plate measuring system (e.g. Anton Paar rheometer MCR302). The frequency was 1 Hz. The measurements were carried out according to ISO standard 6721-10-2015-09. The tested syringe 12 was made of the material, i.e. 1073 mm3 The plunger unit was filled completely with material having a volume of 1.0 mm. The plunger unit used was a standard plunger of type FM257 from the manufacturer Daetwyler.

[0076] A force was applied perpendicularly to the proximal end of the plunger rod unit via the test plunger of the test machine. The test plunger was moved towards the distal end of the syringe with a constant test speed of 12.6 mm / min, while the force acting on the plunger rod unit was continuously increased. A maximum force of 420 N was set, at which the test was interrupted. The acting force was detected by a force sensor with a sampling rate of 200 Hz. The test plunger was then continuously moved until an impermeability ("leak") and / or NPO was observed, i.e. until the measured force suddenly decreased by at least 30%.

[0077] The force acting at the time of occurrence of impermeability and / or NPO was recorded for each measurement and plotted on the diagram shown in FIG. 6. The diagram shown in FIG. 6 represents the results of a series of measurements including 56 measurements. The results shown on the diagram show that none of the 56 measurements resulted in a syringe failure due to NPO or leakage at a force below 100 N. The number of measurements performed of 56 ensures that the NPO minimum resistance can be determined, which is defined by the fact that no more than 1.8% of the syringes tested below said threshold will experience a "needle penetration".

[0078] Since the maximum finger force required to actually operate a syringe is on average 95N, the syringe according to the present invention may avoid the occurrence of NPO and / or leakage.

[0079] 7 shows another diagram illustrating the test results for the ejection force of a syringe according to the invention compared to the ejection force of a product known from the prior art. The different measured values ​​are shown along the x-axis of the diagram. The y-axis represents the measured ejection force. The diagram shows measurements with three different test speeds.

[0080] The syringes according to the embodiment shown in Figs. 1 to 5 were compared with a "SCHOTT COC Standard" syringe with a filling volume of 1 ml (designated "TopPac 1ml Long"). For the plunger unit, a standard plunger of the FM257 type from the manufacturer Daetwyler was used with both syringes. As the needle unit, a needle unit "TSK HYPODERMIC NEEDLE", Ref.: HPC-30013l-320, 30G x 1 / 2 with an open (not flattened) cannula with a thickness of 30G and a length of 13 mm was used with both syringes. As the medium to be extruded, a high-viscosity medium was used. This high-viscosity medium had a storage modulus G' of about 84.5 Pa and a loss factor tan δ of about 0.48. The viscosity was measured at 25° C. and a pressure of 1013.25 hPa using a plate-plate measuring system (e.g., an Anton Paar rheometer MCR302). The frequency was 1 Hz. The measurements were carried out according to ISO standard 6721-10-2015-09.

[0081] Tests were performed with the plunger moving from proximal to distal in the syringe at test speeds of 100 mm / min, 50 mm / min and 10 mm / min. The test results show that at a test speed of 100 mm / min, the ejection force of the syringe according to the present invention is reduced from 172.3 N to 94.9 N compared to the syringe according to the prior art. The test results further show that at a test speed of 50 mm / min, the ejection force of the syringe according to the present invention is reduced from 136.4 N to 73.9 N compared to the syringe according to the prior art. The test results further show that at a test speed of 10 mm / min, the ejection force of the syringe according to the present invention is reduced from 73.5 N to 38.3 N compared to the syringe according to the prior art.

[0082] The ejection force of the syringe 12 according to the invention is therefore significantly less than that of known syringes, so that the syringe according to the invention requires less force to be exerted by the user to deliver a highly viscous medium, which allows for improved metering accuracy, and thus allows the use of needle units with smaller cannula diameters, i.e., diameters of 30 G and above, despite the use of highly viscous media. [Explanation of symbols]

[0083] 10 Injection device 12 Syringe 14 Plunger rod unit 16 Needle Unit 18 Distal end 20 Proximal end 22 Luer lock connector 24 Flange 26 Plunger rod 28 Plunger 30 Grip 32 Needle base 34 Cannula 36 Tip 38 Lid 40 Outer Cone 42 Aperture 44 Sleeve-like part 46 Female thread 50,50' Ridgeline 54,54' valley 56 End face 58 Distal Collar 60 Slope L Longitudinal axis A Distance B distance C Cone total length I1 Minimum inner diameter I2 Maximum Inner Diameter A H Outside diameter B K Width Ridge B G width valley α Angle in the cross section of the thread β Different angles in the cross section of the thread γ Angle of the inclined surface I K Indoor diameter V Capacity L SK full length o distance s bubble length t Plunger length u distance w Length of inclined surface

Claims

1. A syringe (12) for an injection device for injecting a highly viscous medium, comprising: The syringe (12) has a distal end (18) and a proximal end (20); The syringe (12) is hollow and cylindrical and defines a chamber for containing a high viscosity medium; the proximal end (20) has an opening through which a plunger rod unit (14) can be inserted into the chamber; The distal end (18) is formed with a luer lock connector (22) having an outer cone (40) with a relatively wide opening (42) for feeding high viscosity media, and a sleeve-like portion (44) with an internal thread (46); The syringe (12) has a minimum resistance NPO of greater than 90N. Syringe (12).

2. The syringe (12) has an average NPO resistance of at least 100N, preferably at least 105N, preferably at least 110N, more preferably at least 115N, and even more preferably at least 117N. The syringe (12) of claim 1.

3. The female thread (46) has a minimum internal diameter (I) of 7.05 mm to 7.15 mm, preferably 7.08 mm to 7.12 mm, preferably 7.1 mm. １ ) A syringe (12) according to claim 1 or 2.

4. The female thread (46) has a width (B Ｋ ) A syringe (12) according to any one of claims 1 to 3.

5. The female thread (46) has a width (B Ｇ ) A syringe (12) according to any one of claims 1 to 4.

6. a distal end face (56) of said outer cone (40) projects beyond a distal collar (58) of said sleeve-like portion (44) by a distance (A) of 2.1 mm to 2.5 mm, preferably 2.2 mm to 2.4 mm, preferably 2.3 mm; A syringe (12) according to any one of claims 1 to 5.

7. the syringe (12) has at the proximal end (20) an inner circumferential surface with an inclined surface (60), the inclined surface (60) tapering the inner circumferential surface, viewed in a direction from the proximal end (20) towards the distal end (18), the inclined surface (60) having a length (w) of 1.2 mm to 1.8 mm, preferably 1.4 mm to 1.6 mm, preferably 1.5 mm, viewed in the direction of the longitudinal axis (L) of the syringe (12) and / or the inclined surface (60) forms an angle (γ) with the longitudinal axis (L) of at least 13°, preferably at least 14°, preferably at least 15°; A syringe (12) according to any one of claims 1 to 6.

8. The syringe (12) has a maximum overall length (L ＳＫ ) and a maximum interior diameter of 5 mm (I Ｋ ) and the syringe (12) can accommodate a volume (V) of at least 1 ml. A syringe (12) according to any one of claims 1 to 7.

9. the syringe (12) has, at least in the region of the chamber, a wall thickness of at least 1.7 mm, preferably at least 1.8 mm, preferably at least 2.0 mm, more preferably at least 2.2 mm; A syringe (12) according to any one of claims 1 to 8.

10. The syringe (12) is preferably made of a plastic material having an elastic modulus of 2800 MPa to 3300 MPa, in particular 2900 MPa to 3200 MPa; A syringe (12) according to any one of claims 1 to 9.

11. A syringe for injecting a highly viscous medium, comprising: The injector comprises a syringe (12) according to any one of claims 1 to 10 and a plunger rod unit (14), The plunger rod unit (14) includes a plunger rod (26) and a plunger (28) attached to a distal end of the plunger rod (26); The plunger (28) is received in the chamber through an opening formed in the proximal end (20) of the syringe (12) and is movably guided within the chamber. syringe.

12. An injection device (10) for injecting a highly viscous medium, comprising: The injection device (10) comprises a syringe according to claim 11 and a needle unit (16) with a needle hub (32) and a cannula (34), The needle hub (32) has a luer lock connector mating member (36) that is complementary to the luer lock connector (22) of the syringe (12) to form a luer lock connection between the syringe (12) and the needle unit (16). Injection device (10).

13. said cannula (34) has a thickness of at least 31G, preferably at least 32G, preferably at least 33G, more preferably at least 34G, even more preferably at least 35G; and / or the hub (32) has an inner cone, the inner cone having a length along the longitudinal axis of the needle unit (16) of 3 mm to 7 mm, preferably 5.5 mm to 6.5 mm, preferably 6.1 mm; 13. An injection device as claimed in claim 12.

14. 14. A cosmetic method comprising administering a high viscosity cosmetic formulation using a syringe according to any one of claims 1 to 10, an injector according to claim 11 or an injection device according to claim 12 or 13.

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