Needle-free injection device for needle-free injection of an active ingredient solution

Description

[0001] The present invention relates to a needle-free injection device according to the preamble of claim 1.

[0002] Needle-free injection devices are well known in the art. They apply pressure to the active ingredient solution, which is so great that it penetrates the skin's surface.

[0003] There are various options for how the pressure is applied. For example, a distinction is made between a spring-operated clamping mechanism, which exerts spring pressure on a piston, and a pneumatic mechanism, which operates with gas pressure.

[0004] You can also find information on the website http: / / news.mit.edu / 2012 / needleless-injections-0524 the description of a needleless injection device that works with magnetic repulsion.

[0005] In the field of spring-operated tensioning mechanisms, injection devices are already known that feature a lever for tensioning a spring mechanism. Tensioning a drive mechanism, however, is unnecessary with a pneumatic drive, since pressure is already built up and only needs to be released.

[0006] US Pat. No. 6,264,629 B1 presents, among other things, an injection device with a pneumatic mechanism in Fig. 5. The lines of force show that the actuating pressure is applied to a cap axially relative to the device axis.

[0007] Such an axial force application would result in undesirable additional axial pressure on the injector device and thus also on the skin and the injection site. This can, for example, cause unnecessary pain in inflamed areas or worsen the inflammation. Furthermore, considerable pressure must be applied to trigger the gas cartridge. The pressure in the gas cartridge must be relatively high for the application, so that the closure device, which must be destroyed beforehand, is relatively stable.

[0008] US 3 688 765 A is cited as further prior art. This discloses a pen-like gas-operated injection syringe in which a spring-loaded needle is arranged, which is pressed into a stationary gas cartridge by the spring upon actuation of a locking lever.

[0009] US 4 941 880 A discloses a gas-operated injection syringe in which a mandrel, which is arranged in a linearly movable manner in the syringe housing, is pressed into a gas cartridge via a lever mechanism.

[0010] EP 0 295 917 A2 discloses a two-stage actuation mechanism for a gas-operated injection syringe. In a first step, a gas cartridge is pressed onto a cannula. This is achieved by actuating a wing screw at the end. The transitions to the cannula must be sealed accordingly. A lever mechanism closes the opening of the cannula (also gas-tight). In a second step, gas is released from the cannula opening by tilting the lever element and pressing a button on the side.

[0011] The object of the present invention is, in view of the aforementioned prior art, to provide an injection device that is inexpensive to manufacture and easy to operate.

[0012] The present invention solves this problem by providing a needleless injection device having the features of claim 1.

[0013] A needle-free injection device according to the invention is used for the needle-free injection of a solution containing an active ingredient through the skin surface into a subcutaneous tissue located underneath.

[0014] The injection device comprises an injector housing and a gas cartridge. Furthermore, the injection device comprises a piston, for example a rod-shaped syringe piston, which is arranged in the injector housing so that it can be moved, in particular linearly, by pressure resulting from the release of gas from the gas cartridge. For this purpose, the injector housing can have a channel that serves to guide the piston. The piston acts on the active ingredient-containing solution, which can be arranged in a channel that extends linearly in the direction of movement of the piston in the housing.

[0015] The movement of the plunger transfers pressure to the active ingredient solution. The solution is delivered to the subcutaneous tissue via a dispensing port in the needle-free injection device when placed on the skin.

[0016] According to the invention, the needle-free injection device also has a lever element, upon actuation of which the gas cartridge is pressed onto a nozzle arranged within the injector housing and tapering towards the gas cartridge in order to release the gas.

[0017] This releases gas to move the piston and inject the active ingredient solution. The lever element enables easier and less forceful operation of the injector device according to the invention.

[0018] Advantageous design variants of the injection device are the subject of the subclaims.

[0019] The lever element can advantageously be constructed in two or more parts with multiple levers. The respective levers are parts of the lever element.

[0020] At least one lever of the lever element is mounted in such a way that the lever element presses on the gas cartridge at least in part, preferably in a direction that runs parallel to the housing axis of the injector housing, in order to release the gas.

[0021] The lever element, in particular a lever of the lever element, can preferably have two legs which are at an angle to one another such that a force deflection takes place from an actuating force in the radial direction to a housing axis C of the injector housing into an axially directed force.

[0022] The force deflection does not necessarily have to be 90°. Preferably, the force deflection can be at least 70°, particularly preferably 80 to 100°.

[0023] The gas cartridge can be filled in such a way that it releases a gas pressure of at least 100 ATM, preferably more than 180 ATM, onto the piston.

[0024] The needle-free injection device can have a channel filled with the active ingredient-containing solution, with the dispensing opening arranged at its end. The dispensing opening has a diameter that is at least four times, preferably ten times, smaller than the diameter of the channel. This achieves a further increase in pressure before the solution is injected.

[0025] A first of the at least two levers of the lever element can be arranged outside the injector housing, e.g., on its outer circumference, and can have a tilt angle of at least 3°, preferably 5 to 20°, relative to the injector housing. This enables a sufficiently large leverage effect for force transmission.

[0026] The first lever of the lever element may have a substantially linear shape which can be tilted in the form of a rocker about a tilting axis, wherein a first lever arm is at least four times, preferably eight times as long as a second lever arm which acts on a second lever.

[0027] The second lever of the lever element can have a curved shape, in particular an L-shaped shape, wherein a first lever arm of the second lever, on which the first lever acts, is preferably twice as long as a second lever arm for the axial pressure application to the gas cartridge.

[0028] The injection device, in particular the injector housing, can be constructed in several parts, with the individual parts being detachably connected to one another. It can comprise a pneumatic drive unit with the gas cartridge, as well as a power transmission unit for transmitting the pressure to the solution. The power transmission comprises the piston arranged for linear movement within the injector housing. Finally, the injection device can also comprise an active ingredient chamber with a channel for storing and releasing the active ingredient-containing solution into the subcutaneous tissue.

[0029] The injection element may have a locking element which locks the lever element against unintentional use and whose deactivation, e.g. its removal, releases a tilting movement of the lever element.

[0030] The injector housing and the lever element can be made inexpensively from plastic.

[0031] When actuated, the lever element transfers a force to the gas cartridge directly, i.e. without any additional force-transmitting elements such as springs or the like.

[0032] Due to its simple design, the possibility of using cost-effective components and the small number of components, the injection device is suitable for single use.

[0033] The invention will be explained in more detail below using an exemplary embodiment with the aid of the accompanying figures. Fig. 1 shows a schematic sectional view of a first injection device according to the invention; Fig. 2 shows a top view of the injection device according to the invention; Fig. 3 shows a sectional view of the injection device according to the invention at the level of the pivot axis of a lever element; and Fig. 4 shows a schematic sectional view of a second injection device according to the invention,

[0034] Fig. 1-3 shows a variant of an injection device 1 according to the invention.

[0035] The injection device 1 is used for the needle-free injection of a solution containing an active ingredient into a subcutaneous tissue. The injection device 1 comprises an injector housing 2, which in the case of Fig. 1 is divisible into three sensor housing sections 21, 22, and 23. The injector housing sections 21, 22, and 23 can be detachably connected to one another, e.g., by a screw connection.

[0036] A first injector housing section 21 has an end face 31 intended for contact with the skin. The first injector housing section 21 is designed as a pin-shaped sleeve. It comprises a channel 32 for conducting the solution to a dispensing opening 33 for delivering the solution to the skin. The channel 32 has a cross-sectional reduction 34 in the region of the dispensing opening 33. The cross-sectional reduction 34 has a diameter that is at least twice smaller than the diameter in the remaining region of the channel 32, preferably even more than ten times smaller than the diameter of the channel 32. The cross-sectional reduction enables an additional increase in pressure on the dispensed solution before it hits the skin.

[0037] In the initial state, the solution to be injected can be arranged within channel 32. The length of channel 32 can vary depending on the dosage of the solution. This makes it possible to completely fill the channel and cover it at the end with a film or similar material. However, the filling of channel 32 and the assembly of the entire injection device 1 can also be carried out at the factory.

[0038] A rod-shaped syringe plunger 10 can be inserted into channel 32. The syringe plunger 10 has a sealing cap 11 at its end to prevent any solution from escaping to the edge of the syringe plunger 10, which could lead to a reduction in pressure on the remaining solution in channel 32.

[0039] At the interface between the first injector housing section 21 and the adjoining second injector housing section 22, a seal, e.g. a sealing ring, is arranged through which the rod-shaped syringe plunger 10 is movably guided. The second injector housing section has a channel 12 for guiding the rod-shaped syringe plunger 10 and a sealing element 8 arranged at the end and firmly connected to the syringe plunger 10. Due to the dimensioning of the sealing element 8, this channel 12 has a larger diameter than the channel 32 of the first injector housing section 21. At the end of the channel 12, an insert 9 with a central nozzle 13 is arranged, which allows gas to be introduced into the channel 12 and there exerts pressure on the sealing element 8, which sets the injection plunger 10 in a linear movement in the direction of the dispensing opening 33.The nozzle 13 tapers in the opposite direction to the aforementioned linear movement and forms a tip 14 with a gas inlet opening 15, which enables destruction of the gas cartridge in the area of ​​a cartridge closure 4 by piercing the closure and introduction of the released gas into the channel 12.

[0040] The third injector housing section has a receiving space for a gas cartridge. In the specific case of the Fig. 1 A so-called 12 gram gas cartridge 3 was used. Gas cartridges 3 have a mechanically destructible cartridge closure 4. In the case of the embodiment of the Fig. 1 It may be a pierceable cartridge closure. Of course, the cartridge closure must be sufficiently stable to retain the gas pressure within the gas cartridge. Therefore, pneumatically operated injection devices are not always easy to operate; considerable force is required to break the cartridge closure.

[0041] Additional force-assisting components, e.g. springs and / or caps, have usually made the injection device so expensive that its use as a disposable injection device was not possible for cost reasons.

[0042] The present invention offers a significantly simpler and easier-to-handle solution for activating the gas cartridge 3 during operation by means of a two-part lever element 16. The lever element 16 is arranged on the outside of the injector housing 2 in an easily accessible manner. The lever element has a first, substantially linear lever 24 and a second L-shaped lever 25, which interact with each other.

[0043] For arranging the first lever 24, a first lever bearing 17 protrudes from the substantially cylindrical third injector housing section 23. The lever bearing 17 comprises two projections 18, 19 and a gap 20 into which the lever 24 can be inserted at least partially and is tiltably mounted by means of an axle pin 26 arranged in recesses in the two projections 18 and 19. This first lever 24 is also referred to below as a rocker arm. The axle pin 26 defines a tilting axis A, about which the lever 24 executes a tilting movement. The tilting axis divides the lever 24 into a first and a second lever arm 27, 28, wherein the first lever arm 27 is at least four times, preferably at least eight times, as long as the second lever arm 28.

[0044] When the filled gas cartridge 3 is deactivated, the first lever arm 27 is at a maximum distance from the wall of the injector housing 2, and the second, shorter lever arm 28 rests on the wall of the injector housing 2. Starting from the tilt axis A, the lever arm can extend at an angle of preferably more than 3°, for example 5 to 20°, relative to the sensor housing.

[0045] For arranging the second L-shaped lever 25, a second lever bearing 29 protrudes from the substantially cylindrical third injector housing section 23. The second lever bearing 29 is arranged opposite the first lever bearing 17 at an end region 30 of the injector device 1 opposite the end face 31. Analogous to the first lever holder 17, the second lever holder 29 also has two projections 35 and 36 and a gap 37, into which the lever 25 can be inserted at least partially and is pivotably mounted by means of an axle bolt 38 arranged in recesses in the two projections 35 and 36. This first lever 25 is also referred to below as a pivot lever. The movement of this lever redirects an actuating force from a radial direction relative to the injector housing 2 to an axial direction, where the force ultimately presses against the gas cartridge 2.The axle bolt 38 defines a pivot axis B.

[0046] The L-shaped lever has a first lever arm 39, which is preferably at least twice as long as the second lever arm 40. The second lever arm 28 of the first lever 24 engages at the end of the first lever arm 39 and presses the first lever arm 39 away from the injector housing 2 in the radial direction.

[0047] The second lever arm 40 is arcuate, engages an end of the gas cartridge 3 opposite the cartridge closure and, when the first lever arm 39 is actuated in the manner described above, exerts axial pressure on the end of the gas cartridge 3.

[0048] For this purpose, the lever arm 40 has a projection 41 protruding towards the gas cartridge 3 to increase the force, which projection can press directly onto the end of the gas cartridge through a terminal opening 42 in the injector housing.

[0049] By actuating the lever element 16, a targeted force is transmitted to the gas cartridge 3, but only a small amount of axially directed force is applied to the surrounding injector housing 2. The transmitted force presses the gas cartridge onto the nozzle 13 and exerts gas pressure on the syringe plunger, which, through linear movement in channels 12 and 32, exerts high pressure on the active ingredient-containing solution, causing it to penetrate the skin surface. The illustrated injection device 1 is characterized by a small number of parts, which can be manufactured in large quantities. This makes the injection device suitable for use as a single-use injection device, often also referred to as a disposable injector. Subsequent sterilization measures are unnecessary with this type of single-use injection device.

[0050] Apart from the sealing elements described above, the syringe plunger, the nozzle and the gas cartridge, all other parts, in particular the injector housing 2 and the lever element 16, can be made of plastic.

[0051] A CO2 cartridge, e.g., weighing 12 g, can be used as the gas cartridge 3. This gas cartridge can release 200 atm of pressure in the area of ​​the nozzle 13. By reducing the cross-sectional area 34, the terminal diameter in the area of ​​the discharge opening 33 in a preferred range of 0.16 to 0.2 mm compared to the channel 32 with a diameter of preferably between 2 and 4 mm, an additional pressure increase, preferably by a factor of 10, e.g., to 3000 atm, can be achieved.

[0052] Fig. 4 shows a second embodiment of an injection device 51 according to the invention.

[0053] This injection device 51 has, analogous to the variant of the Fig. 1-3 , an injector housing 52 with a cartridge storage space 58 and a gas cartridge 53 arranged linearly displaceably within this cartridge storage space, which can be actuated by a multi-part lever element 63.

[0054] The injector housing has, at its end in the cartridge storage chamber 58, an actuating insert with a tapered nozzle 56 comprising a mandrel for piercing the cartridge closure of the gas cartridge 53 and with a channel for transferring the gas into a piston storage chamber 63 in which a piston 60 is mounted for linear displacement.

[0055] The nozzle 56 is a separate component of the injection device 51, which is held in the remaining injector housing 52 via an insert holder 57 with a cartridge seal.

[0056] The cartridge seal preferably has a cylindrical shape. It preferably serves to linearly guide a terminal extension of the gas cartridge 53.

[0057] Analogous to Fig. 1-3 The injection device 51 also has a combination of two levers 55 and 59, which enables force to be applied to the gas cartridge 53 in a similar way to the first embodiment.

[0058] The syringe plunger 60 acts on a sealing cap 54, which in this variant is not connected to the syringe plunger 60.

[0059] The injection device 51 has a discharge opening at the end, which in the variant of the Fig. 4 designed as a continuation of a channel for guiding the piston 60 in its forward movement and tapering to a point with a narrowing of the cross section.

[0060] The gas cartridge 53, e.g. as a CO2 cartridge, can be inserted interchangeably into the cartridge storage chamber 58.

[0061] The pneumatically operated needleless injection device or syringe can be delivered disinfected, sealed and filled ready for use as a so-called single-use application, if necessary packaged.

[0062] After removing the injection device 51 from its packaging, a rotation lock 62 can be deactivated. The rotation lock 62 can be, for example, a locking pin that prevents the mobility of the lever 55 and the tilt axis A or the pivot axis B of the L-shaped lever 59.

[0063] After removing this locking pin, the force can be transferred to the gas cartridge 53 by operating the lever 55. First, the tip of the injection device 51 is placed on the desired point on the skin. By applying slight finger pressure to the lever 55, it can be moved forward a distance of preferably 10-30 mm, preferably 15-20 mm, until it is pressed against the injector housing 52.

[0064] As a result, the linear movement of the gas cartridge 53 is moved in the direction of the mandrel of the actuating insert, so that the gas cartridge is opened and gas is guided via the channel of the actuating insert onto the syringe plunger 10 or onto a sealing element which is arranged at the end of the syringe plunger 10.

[0065] The force amplification on the gas cartridge 53 can be increased by more than 10 times, even 13 times, compared to a direct, terminal manual pressure on the cartridge base by the ratio of the two lever arms 55 and 59 and their geometric design and bearing.

[0066] This ensures smooth handling and avoids excessive pressure on the injection site. Reference symbol

[0067] 1, 51Injection device 2, 52Injector housing 3, 53Gas cartridge 4Cartridge closure 8Sealing element 9Insert 10, 60Syringe plunger 11, 54Sealing cap 12Channel 13, 56Nozzle 14Tip 15Gas inlet opening 16, 63Lever element 17Lever bearing 18Protrusion 19Protrusion 20Gap 21Sensor housing section / injector housing sections 22Sensor housing section / injector housing sections 23Sensor housing section / injector housing sections 24, 55Lever 25, 59L-shaped lever 26Shaft bolt 27Lever arm 28Lever arm 29, 61Lever bearing 30End area 31End face 32Channel 33Discharge opening 34Cross-section reduction 35Protrusion 36Protrusion 37Gap 38Axle bolt 39Lever arm 40Lever arm 41Protrusion 42Opening 57Insert holder with cartridge seal 58Cartridge storage chamber 62Anti-rotation lock / locking pin 63Piston storage chamber AKilting axis BSwivel axis CHousing axis

Claims

1. Needle-free injection device (1, 51) for the needle-free injection of a solution containing an active agent into a subcutaneous tissue, wherein the injection device (1, 51) has an injector housing (2, 52) and a displaceable gas cartridge (3, 53) and a plunger (10, 60) which is arranged in the injector housing (2, 52) so as to be linearly movable by a pressure due to a release of gas from the gas cartridge (3, 53), wherein the pressure is transferable by the plunger (10, 60) to the solution containing the active agent which can be dispensed to the subcutaneous tissue via a dispensing opening (33) in the needle-free injection device (1, 51) by placing it on the skin, characterized in that the needle-free injection device (1, 51) has a lever element (16, 63), during the operation of which the gas cartridge (3, 53) is pressed onto a nozzle (13, 56) arranged within the injector housing (2, 52) and tapering towards the gas cartridge (3, 53) for the release of gas and thereby releases gas for moving the plunger (10, 60) under injection of the solution containing the active agent, and in that the injector housing (2, 52) has a cartridge storage chamber (58), wherein the gas cartridge (53) is arranged in a linearly displaceable manner within this cartridge storage chamber (58).

2. Needle-free injection device according to claim 1, characterized in that the lever element (16, 63) is constructed in two or more parts with a plurality of levers (24, 25, 55, 59), wherein at least one lever (25, 59) of the lever element (16, 63) is mounted in such a way that the lever element (16, 63) presses on the gas cartridge (3, 53) to release the gas.

3. Needle-free injection device according to claim 1 or 2, characterized in that the lever element (16, 63), in particular a lever (25, 55) of the lever element (16, 63), has two legs which are at such an angle to one another that a force redirection takes place from an actuating force in the radial direction to a housing axis (C) of the injector housing (1, 51) into an axially directed force, wherein the force redirection preferably takes place by at least 70°, particularly preferably by 80 to 100°.

4. Needle-free injection device according to one of the preceding claims, characterized in that the gas cartridge (3, 53) is filled in such a way that it releases a gas pressure of at least 100 ATM, preferably more than 180 ATM, on the plunger (10, 60).

5. Needle-free injection device according to one of the preceding claims, characterized in that the needle-free injection device (1, 51) has a channel (32) which is filled with the solution containing the active agent and has the dispensing opening (33) at its end, wherein the dispensing opening (33) has a diameter which is at least four times, preferably ten times, smaller than the diameter of the channel (32).

6. Needle-free injection device according to one of the preceding claims, characterized in that a first lever (24, 55) of the lever element (16, 63) is formed outside the injector housing (1, 51) with a tilting angle of at least 3°, preferably 5 to 20°, with respect to the injector housing (2, 52).

7. Needle-free injection device according to one of the preceding claims, characterized in that the first lever (24, 55) of the lever element (16, 63) has a substantially linear shape which can be tilted in the form of a rocker about a tilting axis (A), wherein a first lever arm (27) is at least four times, preferably eight times, as long as a second lever arm (28) which engages on a second lever (25, 59).

8. Needle-free injection device according to one of the preceding claims, characterized in that the second lever (25, 59) of the lever element (16, 63) has a curved shape, in particular an L-shaped shape, wherein a first lever arm (39) of the second lever (25, 59), on which the first lever (24, 55) engages, is preferably twice as long as a second lever arm (40) for the axial application of pressure to the gas cartridge (3, 53).

9. Needle-free injection device according to one of the preceding claims, characterized in that the injection device (1, 51), in particular the injector housing (2, 52), is of a multi-part construction, wherein the respective parts are releasably connected to one another, comprising a pneumatic drive unit with the gas cartridge (3, 53), as well as a force transmission unit with the plunger (10, 60) that can be moved linearly in the injector housing (2, 52), and an active substance chamber with the channel (32) for storing and releasing the solution containing the active substance into the subcutaneous tissue.

10. Needle-free injection device according to one of the preceding claims, characterized in that the injection device (1, 51) has a blocking element (62), the deactivation of which releases a tilting movement of the lever element (16, 63).

11. Needle-free injection device according to one of the preceding claims, characterized in that the injector housing (1, 51) and the lever element (16, 63) are made of plastic.

12. Needle-free injection device according to one of the preceding claims, characterized in that the lever element (16, 63) directly transfers a force to the gas cartridge (3, 53) when it is actuated.