Drug autoinjector and related cartridge

Abstract

The invention concerns a drug autoinjector (100) and a related cartridge (30). The drug autoinjector (100) comprises a tubular casing (10) and an actuating device (20) and a cartridge (30) housed in the tubular casing (10). The cartridge (30) comprises: a container body (31), which has a proximal end (31a) and a distal end (31b), which is closed by a wall (34), in which a hole (34a) is formed, tight closed by a membrane (35); a first rubber (33a) for sealing the proximal end (31a) of the container body (31); a needle (40) integral with a support (40), suitably spaced from the first rubber (33a), so that between the first rubber (33a) and the support (41) a first chamber (37a) containing a drug (F) to be injected is delimited, a second chamber (37b) housing the needle (40) being also delimited between the support (41) and the wall (34) closing the distal end (31b) of the container body (31). The cartridge (30) is interchangeable and has, at the proximal end (31a) of the container body (31), means (39) for removable coupling to the tubular casing (10) of the drug autoinjector (100). At least one transverse channel (43) is formed in the support (41) for the needle (40) and at the distal end (31b) of the container body (30), on an inner surface of the container body (31), at least one longitudinal groove (44) is formed, the transverse channel (43) and the longitudinal groove (44) being such as to allow the passage of the drug (F) during the injection. The support (41) for the needle (40) can be operated by the operating device (20) so as to slide tightly in the container body (31) so that the needle (40) passes from a not operative position, in which it is housed inside the second chamber (37b), to an operative position, in which it is extracted from the container body (31) of the cartridge (30).

Description

[0001] DRUG AUTOINJECTOR AND RELATED CARTRIDGE

[0002] DESCRIPTION

[0003] TECHNICAL FIELD

[0004] The present invention relates, in general, to the technical field of drug autoinjectors. More specifically, the present invention relates to a drug autoinjector, in particular life-saving drugs, e.g. epinephrine or adrenaline, and a related cartridge.

[0005] BACKGROUND

[0006] Drug autoinjectors are known, which allow a user, even one who is not particularly experienced, to administer themselves a drug, typically a life-saving drug, immediately, completely independently and without the help of a healthcare professional. These drug autoinjectors are practical and easy to use by the end-user, saving public health care resources.

[0007] A known type of drug autoinjector typically comprises a tubular casing, inside which a syringe, equipped with a needle and piston, is slidingly housed. The syringe is pre-filled with a drug to be administered. The tubular casing has a distal end, i.e. the end at which the syringe needle is housed, enclosed by a lid, while a button, typically a spring- loaded button, for operating the autoinjector protrudes from a proximal end of the tubular casing.

[0008] In use, a user proceeds to remove the lid and compress the distal end of the tubular casing of the autoinjector against his or her skin, keeping the autoinjector perpendicular. Next, the user presses the button, releasing the syringe and the related piston, which slide in succession first to extract the needle from the tubular casing, so that it sticks into the user's body, and then to inject the drug. The return of the needle into the tubular casing is achieved by stopping compressing the distal end of the tubular casing against the skin.

[0009] In another known type of drug autoinjector, the syringe is housed, instead of in a tubular casing, in a cartridge consisting of an inner casing and an outer casing, sliding over each other. In this case, by pressing the distal end of the inner casing (from which the syringe needle will come out) against the skin of a user at the point where the injection is to be made, the outer casing slides forward over the inner casing, unlocking the button. Pressing the button thus unlocked releases the syringe and its plunger, which slide in succession first to stick the needle and then to inject the drug. The return of the needle into the cartridge is achieved by ceasing to compress the distal end of the inner casing against the skin.

[0010] Known autoinjectors of drugs, briefly described above, while having an appreciable advantage in terms of safety of use, nevertheless have some drawbacks.

[0011] Firstly, these drug autoinjectors are of the disposable type. This means that once the drug inside the syringe has been injected, the autoinjectors must be discarded. This leads to problems related to the high amount of waste produced and the costs of waste disposal. Moreover, once used, disposable injectors are not easily recyclable and therefore pollute the environment.

[0012] Secondly, due to the syringe's manufacturing dimensional tolerances, it is virtually impossible to guarantee the injection of all the drug contained in the syringe. This is particularly problematic in the case of drugs such as heparin or specific vaccines, since the injected dose must be very precisely guaranteed.

[0013] Again, most of the current drug autoinjectors that offer this safety of use for the patient turn out to be structurally complex, leading to a cost price that is hardly compatible with that of a disposable device.

[0014] OBJECTS AND SUMMARY OF THE INVENTION

[0015] The main object of the present invention is therefore to provide a drug autoinjector, in particular life-saving drugs or in any case drugs requiring immediate administration, capable of overcoming, or at least limiting, the drawbacks associated with disposable drug autoinjectors of the known type described above.

[0016] More specifically, the main object of the present invention is to provide a drug autoinjector, configured in such a way that it can be reused once the drug contained therein has been injected.

[0017] Yet another object of the present invention is to provide a drug autoinjector, configured in such a way as to allow the injection of different types of drugs, especially drugs that need to be injected immediately when the patient feels the need.

[0018] Another object of the present invention is to provide a drug autoinjector, configured in such a way as to allow immediate injection under sterile conditions.

[0019] Yet another object of the present invention is to provide a drug autoinjector, configured to prevent accidental triggering due to incorrect use, so that it is safe and easy to use even by inexperienced people.

[0020] Another object of the present invention is to provide a drug autoinjector, configured in such a way as to allow the systematic injection of a defined dose of drug.

[0021] Last but not least, an object of the present invention is to provide a drug autoinjector with a simplified design and thus with a cost price compatible with that of a disposable device.

[0022] The invention thus concerns, in a first aspect thereof, a drug autoinjector comprising a tubular casing and an actuating device housed in the tubular casing.

[0023] The drug autoinjector is characterised in that it comprises an interchangeable cartridge, also housed in the tubular casing, which comprises: a container body, which has a proximal end and a distal end, which is closed by a wall, in which a hole is formed, tight closed by a membrane; a first rubber for sealing the proximal end of the container body; a needle integral with a support, suitably spaced from the first rubber, so that between the first rubber and the support a first chamber containing a drug to be injected is delimited, a second chamber housing the needle being also delimited between the support and the wall closing the distal end of the container body.

[0024] The cartridge has, at the proximal end of the container body, means for removable coupling to the tubular casing of the drug autoinjector.

[0025] At least one transverse channel is formed in the support for the needle and at the distal end of the container body, on an inner surface of the container body, at least one longitudinal groove is formed, each transverse channel and each longitudinal groove being such as to allow the passage of the drug during the injection.

[0026] The support for the needle can be operated by the operating device so as to slide tightly in the container body so that the needle passes from a not operative position, in which it is housed inside the second chamber, to an operative position, in which it is extracted from the container body of the cartridge.

[0027] In a second aspect thereof, the invention relates to a cartridge for use with a drug autoinjector as defined above. The cartridge is interchangeable and comprises a container body, which has a proximal end and a distal end, which is closed by a wall, in which a hole is formed, tight closed by a membrane; a first rubber for sealing the proximal end of the container body; a needle integral with a support for sliding tightly in the main body, wherein the support is suitably spaced from the first rubber, so that between the first rubber and the support a first chamber containing a drug to be injected is delimited, a second chamber housing the needle being also delimited between the support and the wall closing the distal end of the container body.

[0028] The cartridge is interchangeable and has, at the proximal end of the container body, means for removable coupling to a drug autoinjector.

[0029] At least one transverse channel is formed in the support for the needle and at the distal end of the container body, on an inner surface of the container body, at least one longitudinal groove is formed, each transverse channel and each longitudinal groove being such as to allow the passage of the drug during the injection.

[0030] Preferred aspects of the invention are set out in the dependent claims.

[0031] Thanks to its particular configuration, in particular thanks to the presence of the cartridge, pre-filled with drug and provided with a sterile needle, which is interchangeable and removably coupled to the tubular casing, the drug autoinjector according to the invention can be reused. In fact, the spent cartridge can simply be removed and replaced with a new one. In other words, the actuating device of the drug autoinjector can be used several times, while the cartridge is interchangeable, i.e. once it has been emptied of the drug it contains, it must be removed and replaced with a new cartridge. As the cartridge is the only component that needs to be replaced after use, the disposal costs of the drug injector and its impact in terms of environmental pollution are minimised.

[0032] In addition, thanks to the special configuration of the interchangeable cartridge, the autoinjector allows immediate injection under the strictest sterile conditions, as well as the injection of a defined dose of drug.

[0033] In the following of the present description, and in the attached claims, the term "distal" will refer to the portion of an autoinjector component arranged on the side of the autoinjector needle, while the term "proximal" will refer to the portion of an autoinjector component arranged on the opposite side of the autoinjector needle.

[0034] Furthermore, in the following of this description and in the attached claims, the expression "spent cartridge" will refer to a cartridge emptied of a drug that has been injected by the autoinjector, while the expression "new cartridge" will refer to a cartridge pre-filled with a drug to be injected by the autoinjector.

[0035] Finally, various directions such as "upper", "lower", "left", "right", "front", "rear" and so on are used with respect to the explanation in combination with the drawings, and thus the components can be oriented differently, e.g. during transport and production as well as during operation.

[0036] BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention is described hereinbelow with reference to certain examples provided by way of non-limiting example and illustrated in the accompanying drawings. These drawings illustrate different aspects and embodiments of the present invention and reference numerals illustrating structures, components, materials and / or similar elements in different drawings are indicated by similar reference numerals, where appropriate.

[0038] Figure 1 is a longitudinal section perspective view of a drug autoinjector according to a preferred embodiment of the present invention.

[0039] Figure 2 is a longitudinal cross-sectional view of an actuating device of the drug autoinjector in Figure 1, which is housed in a non-operative position inside the autoinjector.

[0040] Figure 3 is a longitudinal cross-sectional view of a cartridge of the drug autoinjector in Figure 1.

[0041] Figure 4 is a partial perspective view of a distal end of a cartridge according to another embodiment of the present invention, in an operative position, in which the needle is removed from the cartridge but the drug has not yet been injected.

[0042] Figure 5 is a longitudinal sectional view of Figure 4.

[0043] Figure 6 is a partial longitudinal cross-sectional view of a distal end of a cartridge according to yet another embodiment of the present invention, in the operative position, in which the needle is removed from the cartridge but the drug has not yet been injected.

[0044] Figure 7 is a longitudinal cross-sectional view of the drug autoinjector according to the invention in the operating position, in which the needle is removed from the cartridge but the drug has not yet been injected.

[0045] Figure 8 is a longitudinal cross-sectional view of the drug autoinjector according to the invention in another operative position, in which the drug contained in the cartridge has been injected.

[0046] DETAILED DESCRIPTION OF THE INVENTION

[0047] While the invention is susceptible to various modifications and alternative constructions, certain preferred embodiments are shown in the drawings and are described hereinbelow in detail. It must in any case be understood that there is no intention to limit the invention to the specific embodiment illustrated, but, on the contrary, the invention intends covering all the modifications, alternative and equivalent constructions that fall within the scope of the invention as defined in the claims.

[0048] The use of "for example", "etc.", "or" indicates non-exclusive alternatives without limitation, unless otherwise indicated. The use of "includes" means "includes, but not limited to" unless otherwise indicated.

[0049] With reference to Figures 1 to 3, they show a drug autoinjector according to a preferred embodiment of the present invention.

[0050] The drug autoinjector, generally referred to by reference number 100, comprises a tubular casing 10 and an actuating device 20 and a cartridge 30 housed vertically in the tubular casing 10, coaxial to the tubular casing 10.

[0051] More particularly, the tubular casing 10 is preferably made by injection moulding of plastic material, and within it a proximal cavity 11, substantially cylindrical in shape, for housing the actuating device 20, and a distal cavity 12, also substantially cylindrical in shape, for housing the cartridge 30 are defined. Between the proximal cavity 11 and the distal cavity 12, the tubular casing 10 has a circumferential recess 13. In the circumferential recess 13 an annular seat 14 is formed, the function of which will become clearer later in the present description.

[0052] As shown in detail in Figure 2, the actuating device 20 comprises a plunger 21, also preferably made by injection moulding of plastic material, which comprises a rod 22 having a proximal end 22a and a distal end 22b. From the distal end 22b of the rod 22 of the plunger 21, a head 23 extends, radially outwards.

[0053] The actuating device 20 further comprises a trigger element 24, which is housed at a proximal end 10a of the tubular casing 10. A seat 24a is formed in the trigger element 24, which faces the proximal cavity 11, housing the actuating device 20, and is intended to accommodate the proximal end 22a of the rod 22 of the plunger 21, when the actuating device is in a non-operative position, shown in Figures 1 and 2. The trigger element 24 is also preferably made by plastic injection moulding. A spring 25, preferably helical, surrounds the rod 22 of the plunger 21 and is coaxial with it. The spring 25 is also retained by the trigger element 24.

[0054] In the head 23 of the plunger 21 there is a shoulder 23a, which, in the non-operative position of the actuating device 20, abuts against an abutment surface 14a of the seat 14 of the tubular casing 10. Furthermore, in the non-operative condition, the helical spring 25 is compressed between the trigger element 24 and the head 23 of the plunger 21 of the actuating device 20.

[0055] As shown in detail in Figure 3, the cartridge 30 comprises a substantially cylindrical container body 31, which has a proximal end 31a and a distal end 31b. The proximal end 31a of the container body 31 has an opening 32, which is tight closed by a first rubber 33a, or proximal rubber, which is preferably made of bromubutyl rubber. The distal end 31b of the container body 31 is closed by a wall 34, in which a hole 34a is formed, tight closed by a membrane 35, the task of which is to keep the contents of the cartridge 30 sterile, but at the same time to allow the needle 40 to exit the cartridge 30, when the actuating device 20 of the autoinjector 100 is operated. Preferably, the sealing membrane 35 of the hole 34a is formed by a thin layer of aluminium or injection moulded plastic or any other material that maintains the sterility of the interior of the cartridge 30 and is applied, e.g. welded or glued, onto an external surface 34c of the wall 34 at the hole 34a. As a result, the cartridge 30 is completely sealed to ensure the sterility of all the parts inside it, including the needle 40, which must penetrate the user's body when in use.

[0056] By way of example, the sterilisation of the cartridge 30 takes place by gamma rays. To this end, the container body 31 is preferably made of materials suitable for gammaray sterilisation, such as cyclic olefin polymer material (COP) and cyclic olefin copolymer material (COC).

[0057] Inside the container body 31 of the cartridge 30 there is also a second rubber 33b, or distal rubber, also preferably made of bromubutyl rubber, which has the same dimensions as the first rubber 33a and is suitably spaced from it. The first rubber 33a and the second rubber 33b are positioned opposite each other inside the cartridge 30, i.e. so that corresponding or homologous surfaces 36a and 36b face each other.

[0058] Between the first rubber 33a and the second rubber 33b, precisely between the respective facing surfaces 36a and 36b, a first chamber 37a, or proximal chamber, containing a drug F to be injected by means of the autoinjector 100 is delimited. Between the second rubber 33b and the wall 34 closing the distal end 31b of the container body 31 of the cartridge 30 a second chamber 37b, or distal chamber, is delimited for housing a needle 40.

[0059] The needle 40 is carried by a support 41, which is configured to slide tightly inside the container body 31 of the cartridge 30.

[0060] In the embodiment illustrated in Figures 1 to 5, 7 and 8, the support 41 comprises a first cylindrical portion 41a, having an outer diameter slightly smaller than the inner diameter of the container body 31, i.e. such as to allow the support 41 to slide tightly into the container body 31 of the cartridge 30, followed by a second portion 41b, configured to be coupled, preferably screwed, into an opening 38b formed in the second rubber 33b, on the opposite side to the surface 36b. It follows that the needle 40 is integral with the second rubber 33b and has a tip 42 facing the membrane 35 and suitably spaced from it, e.g. by a few millimetres. Between the first portion 41a and the second portion 41b of the support 41 of the needle 40 there is a transverse channel 43, the function of which will become clearer later in this description. Without departing from the scope of protection of the present invention, it is possible to provide more than one transverse channel 43 between the first portion 41a and the second portion 41b of the support 41 for the needle 40. Preferably, on a surface 41c of the support 41 for the needle 40, facing the wall 34 closing the distal end 31b of the container body 31 of the cartridge 30, there is a gasket 47, for example an O-ring, the function of which is to prevent leakage of the drug F into the cartridge during autoinjection.

[0061] Preferably, an additional gasket 48, e.g. an O-ring, is provided on an outer surface of the first portion 41a of the support 41 to facilitate tight sliding of the support 41 inside the cartridge 30. The gasket 48 also serves to prevent leakage of the drug F.

[0062] Figure 6 shows an alternative embodiment of the cartridge according to the invention, in which no second rubber is provided and the needle 40 is integral with a support 41', which is configured to slide tightly inside the cartridge. To this end, the support 41' has one or more gaskets 48'a and 48'b, e.g. O-rings, at one of its outer surfaces. The gaskets 48a' and 48b' also serve to prevent leakage of the drug F.

[0063] Further, preferably, on a surface 4Tc of the support 41' for the needle 40, facing the wall 34 closing the distal end 31b of the container body 31 of the cartridge 30, there is a gasket 47 / for example an O-ring, the function of which is to prevent leakage of the drug F into the cartridge during autoinjection. In the support 41' of the needle 40 there is a transverse channel 43', the function of which will become clearer later in this description.

[0064] The cartridge 30 is removably coupled to the tubular casing 10 of the autoinjector. To this end, a circumferential protrusion 39 is formed at the proximal end 31a of the container body 31 of the cartridge 30, which, and as can be seen in Figure 1, is adapted to be inserted, in use, into the seat 14 formed in the tubular casing 10 of the drug autoinjector 100, in which, in the non-operative condition, the head 23 of the plunger 21 is also housed.

[0065] In the coupled position, the cartridge 30 is positioned vertically in the distal cavity 12 of the tubular casing 10, coaxial to the tubular casing 10, with the second chamber 37b housing the needle 40 which, preferably, protrudes from the tubular casing 10.

[0066] In particular, the insertion of the circumferential protrusion 39 of the cartridge 30 into the annular seat 14 of the tubular casing 10 takes place by snap-fit, e.g. by rotating the cartridge 30 so as to activate a bayonet connection. In this case, flat portions (not visible in the figures) are formed in the circumferential projection 39. In this way, the cartridge 30 is securely attached to the tubular casing 10 of the drug injector 100, without accidental shock or misuse causing the cartridge 30 to separate from the drug autoinjector 100.

[0067] At its distal end 31b, the container body 31 of the cartridge 30 has at least one longitudinal groove 44 formed on an inner surface thereof. In the embodiment illustrated in the figures, several longitudinal grooves 44 are provided, parallel to each other and equally spaced, so as to form a toroidal ring on the inner surface of the container body 31. It is important that the longitudinal dimension and position of the groove or grooves 44 are such as to place the first chamber 37a of the cartridge 30, containing the drug F to be injected, into fluid communication with the transverse channel 43, which in turn is into fluid communication with the needle 40, during injection of the drug F. More specifically, the transverse channel 43, 43' and the longitudinal grooves 44 are formed in the cartridge 30 in such a way that the plane of symmetry of the transverse channel 43, 43' and the plane of symmetry of the longitudinal grooves 44 coincide. In this condition, in fact, the transverse channel 43, 43' and the longitudinal grooves 44 are into communication and the drug F can flow from one to the other so that the first chamber 37a containing the drug F is into fluid communication with the needle 40.

[0068] In particular, each longitudinal groove 44 has a length at least equal to the thickness of the second rubber 33b, increased by an amount necessary to connect the transverse channel 43, formed in the support 41 for the needle 40, with the first chamber 37a containing the drug F to be injected. Furthermore, and as can be seen in Figure 7, the longitudinal grooves 44 are positioned on the inner surface of the container body 31 of the cartridge 30 in such a way that, when the first portion 41a of the support 41 for the needle 40 is against an inner surface 34b of the wall 34 closing the distal end 31b of the container body 31, the second rubber 33b of the cartridge 30 is located at the longitudinal grooves 44.

[0069] A detail of a cartridge according to an alternative embodiment of the present invention is shown in Figures 4 and 5. This cartridge is entirely similar to the cartridge 30, described above and illustrated in Figure 3, from which it differs in that the cartridge body 31 has an annular extension 45. In particular, the annular extension 45 extends from the wall 34 closing the distal end 31b of the container body 31 and is provided with openings 46. It follows that in use, specifically when the autoinjector 100 is pressed against the surface of a user's skin, the air present in the second chamber 37b advantageously flows outwards through the openings 46 of the annular extension 45, so that the needle 40 can more easily penetrate the skin.

[0070] During production, the cartridge 30 must be filled with the drug using appropriate filling machines. To this end, there are three filling modes for filling the cartridge.

[0071] According to a first filling mode, in the container body 31, already provided with the membrane 35 sealing the hole 34a for the needle 40 to exit, the second rubber 33b- needle support 41-needle 40 assembly is inserted in the correct vertical position. In this correct position, the needle 40 is housed vertically in the second chamber 37b of the cartridge 30.

[0072] Next, the first chamber 37a of the container body 31 is filled with a desired volume of drug F and closed with the first rubber 33a. Preferably, and in order to facilitate the insertion of the first rubber 33a into the container body 31 filled with the drug F, a hole (not visible in the figures) is made in the first rubber 33a for air to escape between the first rubber 33a and the drug F contained in the first chamber 37a of the cartridge 30. Finally, the hole made in the first rubber 33a is closed with a plug (also not shown) to prevent the drug F from escaping.

[0073] In accordance with a second filling mode, in the container body 31, already provided with the membrane 35 sealing the exit hole 34a of the needle 40, the second rubber 33b-needle support 41-needle 40 assembly is inserted in the correct vertical position. In this correct position, the needle 40 is housed vertically in the second chamber 37b of the cartridge 30.

[0074] Next, the first rubber 33a is inserted into position, which is pierced with a double channel needle, basically a stainless steel catheter. In one channel of the catheter, the drug F enters, and air escapes from the other channel. Once the filling has been completed, the needle-catheter is removed and the hole made in the first rubber 33a by the needlecatheter is plugged so that the drug F cannot escape from the cartridge.

[0075] The third mode of filling the cartridge 30 with the drug F is the most suitable for current filling machines.

[0076] In practice, in the container body 31, already provided with the membrane 35 sealing outlet hole 34a of the needle 40, the second rubber 33b-needle support 41-needle 40 assembly is inserted in the correct vertical position. In this correct position, the needle 40 is housed vertically in the second chamber 37b of the cartridge 30.

[0077] Subsequently, and before inserting the first rubber 33a, a vacuum is created in the first chamber 37a of the container body 31, whereby the second rubber 33b-needle support 41-needle 40 assembly is sucked in, thereby ensuring that the air escapes completely. Then, in a condition of negative pressure, the drug F is injected into the first chamber 37a, with consequent displacement of the second rubber 33b-needle support 41- needle 40 assembly to its initial position, with the tip 42 of the needle in the vicinity of the membrane 35 and sufficiently distanced from it so as to prevent it from piercing the membrane 35 prior to actuation of the autoinjector 100 by a user. At this point, still under negative pressure, the first rubber 33a is inserted.

[0078] The operation of the drug autoinjector 100 according to the present invention is apparent to a person skilled in the art from what has been described and will be set out below with reference to Figures 7 and 8. The operation will be described with reference to a cartridge 30 of the type described above and illustrated in Figure 3, but it is understood that a substantially similar argument applies in the case of a cartridge illustrated in Figure 6.

[0079] As described above, in the non-operative position of the drug autoinjector 100, shown in Figure 1, the helical spring 25 is compressed between the trigger element 24 and the head 23 of the plunger 21 of the actuating device 20. In addition, the head 23 of the plunger 21 is housed in the seat 14 of the tubular casing 10, facing the first rubber 33a housed in the casing 31 of the cartridge 30 and spaced from it by a few millimetres.

[0080] It is assumed, now, that a user wishes to administer to himself / herself the drug F present in the cartridge 30 of the drug autoinjector 100.

[0081] First, the user grips the tubular casing 10 and positions the autoinjector 100, pressing the distal end 31b of the container body 31 of the cartridge 30 against the surface of his or her skin, so that the longitudinal axis of the cartridge 30 is perpendicular to the surface of the skin. Subsequently, the user activates the autoinjector 100 by acting on the trigger element 24 in the direction of pressing it. As a result of the pressure exerted on the trigger element 24, the latter releases the helical spring 25, which extends, pushing the plunger 21 and with it the first rubber 33a of the cartridge 30 forward, i.e. inside the first chamber 37a of the cartridge 30.

[0082] When the first rubber 33a is pushed by the head 23 of the plunger 21, it transmits motion to the second rubber 33b (or directly to the support 41', in the absence of the second rubber) by means of the drug F interposed between them. As a result, the needle 40, carried by the support 41 integral with the second rubber 33b (or directly the support 41', in the absence of the second rubber), moves forward until it perforates the membrane 35 which seals the hole 34a formed in the wall 34 of the cartridge 30.

[0083] More specifically, when the user activates the autoinjector 100, the plunger 21, moved by the helical spring 25, pushes the first rubber 33a upwards. Since between the first rubber 33a and the second rubber 33b (or the support 41', in the absence of the second rubber) the drug F, i.e. an incompressible liquid, is present, the entire system inside the container body 31 of the cartridge 30, i.e. the first rubber 33a, the drug F present in the first chamber 37a, the second rubber 33b and the support 41 coupled thereto (or the support 41', in the absence of the second rubber) and the needle 40 integral with the support, moves forward by an amount, typically a few millimetres, such that the tip 42 of the needle 40 pierces the membrane 35. In fact, the air contained in the second needle housing chamber 37b is compressible. Once the membrane 35 has been perforated, the air contained in the second chamber 37b of the cartridge 30 can escape from the second chamber 37b through the hole 34a formed in the wall 34, allowing further forward movement of the needle 40, until it is completely extracted from the cartridge 30.

[0084] This operative condition is shown in Figure 7, in which the first portion 41a of the needle support 41 is in abutment against the inner surface 34b of the container body 34 and the needle 40 is fully withdrawn from the cartridge 30. Since the cartridge 30 presses against the user's skin, and being the longitudinal axis of the cartridge 30 normal to the surface of the user's skin, the needle 40 can pierce the skin to make the injection, penetrating to the maximum depth permitted thereto, into the user's muscle.

[0085] At this point, and as can be seen in Figure 8, the plunger 21 pushes the first rubber 33a forward until it comes into abutment with the second rubber 33b. As the first rubber 33a advances towards the second rubber 33b, the drug F is injected, through the needle 40, into the body of the user, passing through the transverse channel 43 formed in the support 41 of the needle 40 and the longitudinal grooves 44 formed on the inner surface of the container body 31.

[0086] When the injection is complete, the user can proceed to remove the spent cartridge 30 from the autoinjector 100 and insert a new cartridge into the autoinjector 100. Preferably, before removing the spent cartridge 30 from the autoinjector, the needle 40 can be covered with a cap (not shown). This is to avoid accidental injections. As an alternative to the cap, the needle 40 can be fitted with a spring-loaded cap (not shown in the drawings), which retracts when the autoinjector 100 is pressed against the user's skin and extends, covering the needle 40, when, at the end of the injection, the autoinjector is distanced from the skin.

[0087] Before inserting a new cartridge 30, the actuating device 20 must be manually reset to its non-operative position. To this end, the user, acting on the head 23, pushes the plunger 21 backwards, thereby compressing the spring 25, until the proximal end 22a of the rod 22 of the plunger 21 is seated in the seat 24a of the trigger element 24 and the head 23 of the plunger 21 is seated in the annular seat 14 of the tubular casing 21, with the shoulder 23a in abutment against the abutment surface 14a of the seat 14.

[0088] Once the actuating device 20 has been re-armed, the new cartridge 30 is inserted vertically into the tubular casing 10 of the drug autoinjector 100 until the circumferential protrusion 39 snap fits into the annular cavity 14 formed in the tubular casing 10, between the first cavity 11 and the second cavity 12. The new cartridge 30 is thus securely attached to the autoinjector 100 without accidental shocks or misuse dislodging it from the autoinjector 100. From the above description the characteristics of the drug autoinjector object of the present invention are clear, as are the relative advantages. In particular, the drug autoinjector according to the invention can be reused once the drug contained therein has been injected, thus being sustainable in terms of environmental pollution. In addition, the autoinjector described above allows drugs of different types to be injected immediately and under conditions of maximum sterility and safety. Again, manufacturing and assembly costs are very contained. The few constituent elements are in fact easy to make and involve assembly along a single axis.

[0089] Finally, it is clear that the drug autoinjector thus conceived is susceptible to numerous modifications and variants; furthermore, all the details can be replaced with other technically equivalent elements. In practice, the materials used, as well as their dimensions, can be of any type according to the technical requirements.

Claims

CLAIMS1. Drug autoinjector (100) comprising a tubular casing (10) and an actuating device (20) housed in the tubular casing (10); characterized in that it comprises an interchangeable cartridge (30), also housed in the tubular casing (10), which includes: a container body (31), which has a proximal end (31a) and a distal end (31b), which is closed by a wall (34), in which a hole (34a) is formed, tight closed by a membrane (35);- a first rubber (33a) for sealing the proximal end (31a) of the container body (31); a needle (40) integral with a support (41; 41') suitably spaced from the first rubber (33a), so that between the first rubber (33a) and the support (41) a first chamber (37a) containing a drug (F) to be injected is delimited, a second chamber (37b) housing the needle (40) being also delimited between the support (41) and the wall (34) closing the distal end (31b) of the container body (31); wherein the cartridge (30) has, at the proximal end (31a) of the container body (31), means (39) for removable coupling to the tubular casing (10) of the drug autoinjector (100); wherein at least one transverse channel (43; 43') is formed in the support (41; 41') for the needle (40) and at the distal end (31b) of the container body (31), on an inner surface of the container body (31), at least one longitudinal groove (44) is formed, said at least one transverse channel (43; 43') and said at least one longitudinal groove (44) being such as to allow the passage of the drug (F) during the injection; and wherein the support (41; 41') for the needle (40) can be operated by the operating device (20) so as to slide tightly in the container body (31) so that the needle (40) passes from a not operative position, in which it is housed inside the second chamber (37b), to an operative position, in which it is extracted from the container body (31) of the cartridge (30).

2. Autoinjector (100) according to claim 1, wherein inside the tubular casing (10) there are defined a proximal cavity (11), housing the actuation device (20) and a distal cavity (12), housing the cartridge (30), between which there a circumferential recess (13) is present, in which an annular seat (14) is formed, said removable coupling means of the cartridge (30) consisting of a circumferential protrusion (39), which it is formed at the proximal end (31a) of the container body (31) of the cartridge (30) and is suitable for being snap fitted into the annular seat (14).

3. Autoinjector (100) according to claim 1 or 2, wherein the actuating device (20)comprises a plunger (21), which comprises a rod (22), from a distal end (22b) of which a head (23) extends radially towards the outside, and a spring (25) positioned around the rod (22) of the plunger (21) and coaxial with it.

4. Autoinjector (100) according to claim 3, when dependent on claim 2, wherein a shoulder (23a) is formed in the head (23) of the plunger (21), wherein the shoulder (23a) abuts against an abutment surface (14a) of the seat (14) of the tubular casing (10), in the not operative position of the actuating device (20).

5. Autoinjector (100) according to claim 3 or 4, wherein the actuating device (20) further comprises a trigger element (24), which is housed at a proximal end (10a) of the tubular casing (10), wherein the spring (25) is retained by the trigger element (24) and wherein a seat (24a) is formed in the trigger element (24) to accommodate a proximal end (22a) of the rod (22) of the plunged (21), when the operating device (20) is in the not operative position.

6. Autoinjector (100) according to any one of the preceding claims, further comprising a second rubber (33b) and wherein the support (41) for the needle (40) comprises a first cylindrical portion (41a) and a second portion (41b), configured to be coupled into an opening (38b) formed in the second rubber (33b), said at least one transverse channel (43) being formed between the first portion (41a) and the second portion (41b) of the support (41) of the needle (40).

7. Autoinjector (100) according to any one of the preceding claims, wherein at least one gasket (48; 48a', 48b') is present on an external surface of the support (41; 41') for the needle (40) to facilitate tight sliding inside the cartridge (30) and prevent leakage of the drug (F) and wherein on a surface of the support (41; 41') for the needle (40) facing the closing wall (34) of the distal end (31b) of the container body (31) of the cartridge (30) there is a gasket (47; 47') to prevent leakage of the drug (F).

8. Autoinjector (100) according to claim 6, wherein the first rubber (33a) and the second rubber (33b) are positioned opposite to each other inside the cartridge (30), so that corresponding surfaces (36a, 36b) face each other.

9. Autoinjector (100) according to any one of the preceding claims, wherein an annular extension (45) extends from an external surface (34c) of the wall (34) closing the distal end (31b) of the container body (31) of the cartridge (30), in which air escape openings (46) are formed in the annular extension (45).

10. Cartridge (30) for use in a drug autoinjector (100) according to any one of the preceding claims, the cartridge (30) comprising:- a container body (31), which has a proximal end (31a) and a distal end (31b), which is closed by a wall (34), in which a hole (34a) is formed, tight closed by a membrane (35);- a first rubber (33a) for sealing the proximal end (31a) of the container body (31);- a needle (40) integral with a support (41; 41'), which tight slides in the container body (31), wherein the support (41; 41') is suitably spaced from the first rubber (33a), so that between the first rubber (33a) and the support (41; 41') a first chamber (37a) containing a drug (F) to be injected is delimited, a second chamber (37b) housing the needle (40) being also delimited between the support (41; 41') and the wall (34) closing the distal end (31b) of the container body (31); wherein the cartridge (30) is interchangeable and has, at the proximal end (31a) of the container body (31), means (39) for removable coupling to the tubular casing (10) of the drug autoinjector (100); and wherein at least one transversal channel (43; 43') is formed in the support (41; 41') for the needle (40) and at the distal end (31b) of the container body (31), on an inner surface of the container body (31), at least one longitudinal groove (44) is formed, said at least one transversal channel (43; 43') and said at least one longitudinal groove (44) being such as to allow the passage of the drug (F) during the injection.

11. Cartridge (30) according to claim 10, wherein the removable coupling means of the cartridge (30) consists of a circumferential protrusion (39), which is formed at the proximal end (31a) of the container body (31) and is suitable for being snap inserted into an external casing of the drug autoinjector (100).

12. Cartridge (30) according to claim 10 or 11, further comprising a second rubber (33b) and wherein the support (41) for the needle (40) comprises a first cylindrical portion (41a) and a second portion (41b), configured to be coupled into an opening (38b) formed in the second rubber (33b), said at least one transverse channel (43) being formed between the first portion (41a) and the second portion (41b) of the support (41) of the needle (40).

13. Cartridge (30) according to any one of claims 10 to 12, wherein at least one gasket (48; 48a', 48b') is present on an external surface of the support (41; 41'), for the needle (40) to facilitate tight sliding of the support (41; 41') inside the cartridge (30), and prevent leakage of the drug (F), and wherein on a surface of the support (41; 41') for the needle (40) facing the closing wall (34) of the distal end (31b) of the container body (31) of the cartridge (30) there is a gasket (47; 47') to prevent leakage of the drug (F).

14. Cartridge (30) according to claim 12, wherein the first rubber (33a) and the second rubber (33b) are positioned opposite to each other inside the cartridge (30), so thatcorresponding surfaces (36a, 36b) face each other.

15. Cartridge (30) according to any one of claims 10 to 14, wherein an annular extension (45) extends from an external surface (34c) of the wall (34) closing the distal end (31b) of the container body (31) of the cartridge (30), in which air escape openings (46) are formed in the annular extension (45).

Images