WO2010128406A1

WO2010128406A1 - Injection device with tamperproof collar

Info

Publication number: WO2010128406A1
Application number: PCT/IB2010/001427
Authority: WO
Inventors: Michel Vernizeau; Cédric FOUCHER; Lionel Lefebvre
Original assignee: Becton Dickinson France SA
Current assignee: Becton Dickinson France SA
Priority date: 2009-05-06
Filing date: 2010-05-06
Publication date: 2010-11-11
Anticipated expiration: 2011-11-06
Also published as: FR2945216B1; FR2945216A1

Abstract

The present invention relates to a piston rod (1) intended to be connected to a piston (15) of a container (11) of an injection device (101), the said piston rod (1) comprising at its proximal end a bearing surface (3) for allowing a user to exert a distal pressure on the said piston rod (1) when the latter is connected to the said piston (15), characterized in that the said piston rod (1) comprises a collar (5) situated distally with respect to the said bearing surface (3), the said collar (5) being connected to the said piston rod (1) by frangible connection means (9). The invention also relates to an injection device (101) provided with such a piston rod (1).

Description

Injection device with tamperproof collar

The present invention relates to a piston rod for an injection device of the prefilled type, containing a ready-to-use product to be injected, comprising means for preventing access to the product, in particular once the device has been packaged for example in a blister-type plastic packaging. The invention also relates to a prefilled injection device comprising such a piston rod.

Injection devices of the prefilled type generally comprise a container filled with a product intended to be expelled through the distal end of the said container, and a piston connected to a piston rod for moving the piston within the container during the injection.

In the present patent application, the distal end of a part means the end furthest away from the user of the device and the proximal end means the end closest to the user of the device. Likewise, in the present patent application, distal direction means the injection direction and proximal direction means the opposite direction.

In the field of prefilled ready-to-use injection devices, systems have already been described which make it possible to determine whether or not the injection device has already been used. These systems generally relate to the distal end of the injection device, that is to say the needle end of the device. It has thus been proposed to cover the needle with a cap which has to be broken before the injection device can be used.

However, in the case of prefilled injection devices, it is useful to provide an arrangement preventing access to the product before use through the proximal end of the container, even once the injection device and its piston rod are packaged for example in a blister.

During the process of manufacturing this type of prefilled injection devices, the latter are filled under sterile atmosphere and then packaged and optionally sterilized. The packaging is generally of the blister type, that is to say based on a thermoformed more or less rigid plastic material completely enclosing the injection device and matching the overall shape thereof.

However, it has been found that it is relatively easy to pierce such a plastic packaging with a needle and, by applying a given orientation to this needle, to slide it along the piston rod then between the piston and the wall of the container in order to reach the product contained in the prefilled injection device. Figure 6 illustrates this problem with an injection device of the prior art. On Figure 6 is shown an injection device 200 of the prior art, in a storage position, comprising a container 202 having a general tubular shape and open at its distal end 202a and at its proximal end 202b. The container 202 is prefilled with a product 205 and is closed at its distal end 202a by a cap 206. In its proximal region, the container 202 is closed by a piston 204 which is linked to the distal end 203a of a piston rod 203. The piston rod 203 is provided at its proximal end with a transversal wall 203b intended to serve as a bearing surface for the user. Figure 6 is a schematic side view of the injection device 200 in which the container wall 202c, the piston 204 and the part of the piston rod 203 which is received within the container 202 are shown in dotted lines, and in which a blister-type plastic film 201 enveloping the prefilled injection device 200 is shown in section. As appears from the Figure 6, it is possible, with such a packaged injection device of the prior art, to use a conventional needle 207 by grasping said needle by its proximal end 207b and to pierce the blister-type plastic 201 with the distal end 207a of the needle. The person then applies a given orientation to the needle 207 by pushing its distal end 207a along the piston rod 203 and the wall 202c of the container 202, and then sliding it between the external surface 204a of the piston 204 and the wall 202c of the container 202 in order to reach the product 205 contained in the prefilled injection device 200. The product thus rendered accessible can be withdrawn wholly or partly before the normal use of the prefilled injection device. In certain cases, the product is then fraudulently replaced by another liquid, thereby making the injection device ineffective for its intended use, or even dangerous. The present invention aims to overcome this problem by providing a piston rod intended to be used with a prefilled injection device, this piston rod being provided with means making it possible to prevent access to the product through the proximal end of the container, in particular by means of a needle, and in particular when the injection device and the said piston rod are packaged for example in a blister.

The present invention aims to overcome this problem by providing a piston rod intended to be used with a prefilled injection device, this piston rod being provided with means for preventing access to the product through the proximal end of the container, in particular by means of a needle, and especially when the injection device and the said piston rod are packaged for example in a blister. The present invention relates to a piston rod intended to be connected to a piston of a container of an injection device, the said piston rod comprising at its proximal end a bearing surface for allowing a user to exert a distal pressure on the said piston rod when the latter is connected to the said piston, characterized in that the said piston rod comprises a collar situated distally with respect to the said bearing surface, the said collar receiving the said piston rod and being connected to the said piston rod by frangible connection means, said frangible connection means defining a space "e" between the collar and the piston rod, the maximum value of which is less than or equal to 1 mm.

For the purposes of the present invention, "frangible connection means" are intended to mean connection means capable of fracturing under the action of a force greater than or equal to the force necessary to move the piston when the piston rod is connected to the piston of the container of the injection device with which the said piston rod is used, the said force being, for example, exerted on the said piston rod while the said collar is maintained immobile.

The frangible connection means of the piston rod and the limited space "e" they define force a needle to be deviated from the pathway that a fraudulent user would like it to follow in order to reach the product present in the container. In the piston rod of the invention, the frangible connection means constitute a zigzag obstacle that a needle, intended to be used as shown on Figure 6, can not bypass.

Thus, if an unauthorized person attempts to reach the product contained in a prefilled injection device with which the piston rod according to the invention is used, he must first of all fracture the frangible connection means of the piston rod according to the invention, in particular when the prefilled injection device and the piston rod according to the invention are already packaged in a plastic packaging. Thus, the authorized future user can immediately observe that the injection device has been forced or sabotaged.

The piston rod according to the invention thus makes it possible to secure the injection devices, in particular of the prefilled type, with which it is used, in particular by preventing access to the product through the proximal end of these devices by means of a needle. Advantageously, the piston rod according to the invention is provided at its distal end with a rigid disc. In one embodiment of the invention, the said frangible connection means comprise a continuous web of material provided between the said collar and the said piston rod. For the purposes of the present application, "continuous web of material" means that the collar and the piston rod are connected to one another without discontinuity by means of a wall having a particularly slender thickness capable of breaking under the action of a force as defined above. In such a case, for example, the space "e" defined above is filled by the said continuous web of material. Such an embodiment makes it possible in particular to hinder the passage of a needle for example between the collar and piston rod, such that any passage of this type will leave a trace which will be visible to the authorized user.

In another embodiment of the invention, the said frangible connection means comprise at least one discrete bridge of material provided between the said collar and the said piston rod. Such an embodiment makes it possible to leave only a small gap between the collar and the piston rod, for example in the space "e" defined above, and thus makes it possible to oblige a needle, which a person might wish to pass between the collar and the piston rod, to follow an imposed direction: this makes it possible in particular to prevent such a needle from reaching the product present in the container when the piston rod according to the invention is connected to the piston of a container of a prefilled injection device. In embodiments, a needle thus engaged will be blocked in its distal movement by the rigid disc provided at the distal end of the piston rod.

In one embodiment of the invention, the said piston rod and the said collar are produced as a single part. For example, the said part is produced by injection moulding of a thermoplastic material.

In one embodiment of the invention, the said piston rod comprises an elongate rod having a cross section in the form of a cross having four branches. Advantageously, in such an embodiment of the piston rod, the end of each branch is connected to the said collar by at least one discrete bridge.

In one embodiment of the invention, the said collar is provided with a distal skirt provided on its inner wall with radial projections. Thus, the collar can be clipped onto an outer radial rim of the container of the injection device with which the said collar is used. The present invention also relates to an injection device comprising at least: - a container at least partially filled with a product to be injected, the said container comprising at its distal end an end-piece intended to receive a needle,

- a piston housed within the said container, proximally with respect to the said product and capable of moving distally within the said container in order to expel the said product through the distal end of the said container, characterized in that it additionally comprises a piston rod as defined above, the said collar being situated proximally at the proximal end of the said container when the said piston rod is connected to the said piston. Thus, in the injection device according to the invention, the collar, which is situated between the proximal end of the container and the bearing surface of the piston rod, leaves no gap or only a very little gap between the collar and the piston rod. In particular, the collar closes the possible angle between the bearing surface of the piston rod and the proximal end of the container for the introduction of a needle. For example, even when the injection device according to the invention is packaged in a blister, if an unauthorized person pierces the blister by means of a needle, he will then find it impossible to impart a suitable direction on the needle to reach the product present in the container. Specifically, the needle is prevented from following the path that the person wishes to see it take through the presence of the collar of the piston rod according to the invention, this collar forming a chicane on the path of the needle or else entrapping the needle.

In one embodiment of the injection device according to the invention, the said proximal end of the container is provided with an outer radial rim and the said collar is then clipped onto the said outer radial rim by means of the said radial projections. Such an embodiment allows an additional verification that the injection device has not been used before its authorized use. Specifically, the said radial projections constitute frangible means for connecting the collar to the container of the injection device according to the invention.

In one embodiment of the injection device according to the invention, the said injection device is packaged in a blister-type plastic packaging.

The present invention will now be described in more detail by means of the description which follows and the attached drawings, in which: - Figure 1 is a perspective view of a first embodiment of a piston rod according to the invention,

- Figure 2 is a view in section of an injection device according to the invention provided with the piston rod according to Figure 1 , - Figure 3 is a view in section along line AA of Figure 2 of the injection device of Figure 2,

- Figure 4 is a perspective view of a second embodiment of the piston rod according to the invention,

- Figure 5 is a view in section of the collar of the piston rod of Figure 4,

- Figure 6 is a side view of an injection device of the prior art.

With reference to Figure 1 , a piston rod 1 according to the invention is represented. The piston rod 1 conventionally comprises an elongate rod 2 comprising a proximal end 2a and a distal end 2b. At its proximal end 2a, the elongate rod 2 is provided with a proximal transverse wall 3, which is circular in the example represented, serving as a bearing surface for exerting a pressure on the piston rod 1 during its use.

In the example represented, the piston rod 1 is also provided at its distal end with a rigid disc 20 and with means for connection to a piston (see Figure 2) in the form of a screw 4. In other embodiments of the invention which are not represented, the screw 4 could be replaced by a snap-fastening system or by a friction connection.

The piston rod 1 according to the invention is provided with a collar 5, situated distally with respect to the proximal transverse wall 3. In the example represented, the collar 5 is formed by a circular transverse wall 6 provided with a distal skirt 7 spaced apart from the elongate rod 2 by a space "e" whose maximum value is less than or equal to 1 mm. As appears from this Figure, the value "e" represents the distance between the collar 5 and the piston rod 1 , here the elongate rod 2. In the embodiment shown on this Figure, the value "e", in other words the distance between the collar 5 and the piston rod 1 , is constant on the entire periphery of the piston rod 1.

As is apparent from Figure 2, the distal skirt 7 is provided on its inner wall with radial projections 8.

The collar 5 is connected to the piston rod 1 by frangible connection means in the form of a continuous web 9 of material. In particular, in the example represented, the continuous web 9 of material fills the space "e situated between the collar 5 and the piston rod 1 , the elongate rod 2 in the example shown. With reference to Figure 3, the elongate rod 2 of the piston rod

I has a cross section in the form of a cross having four branches 10, and the continuous web 9 of material matches the outer shape of these four branches 10. For example, the piston rod 1 and the collar 5 of the embodiment shown in Figures 1 to 3 are produced as a single part, for example by injection moulding of a thermoplastic material. Thus, in particular, the material forming the transverse wall 6 of the collar 5, the continuous web 9 of material and the elongate rod 2 is the same: however, the thickness of the portion forming the continuous web 9, represented in broken lines in Figure 3, is substantially more slender than the portions respectively forming the transverse wall 6 of the collar 5 and the elongate rod 2 of the piston rod 1 , as is clearly apparent from the view in section according to Figure 2. In consequence, the continuous web 9 forms frangible connection means for connecting the collar 5 to the piston rod 1.

With reference to Figure 2, the piston rod 1 of Figure 1 is used with an injection device 101 according to the invention.

The injection device 101 comprises a container 11 at least partially filled with a product to be injected, for example a medicinal liquid 12. The container 11 may be, for example, a glass or plastic syringe body. The container 11 is provided at its distal end with an end piece 13 intended to receive a needle (not shown) in order to carry out the injection. In the example represented, the end piece 13 is provided with a cap 14 closing the container

I I in a sealed manner in the storage position of the injection device 101 according to the invention, before use. The injection device 101 also comprises a piston 15 housed within the container 11 proximally with respect to the medicinal liquid 12 to be injected. Thus, the piston 15 closes in a sealed manner the inner volume of the container 11 containing the medicinal liquid 12. In this configuration, the injection device 101 according to the invention can be stored and provided prefilled to the final user. As is apparent from Figure 2, the injection device 101 according to the invention is preferably provided with the piston rod 1 screwed to the piston 15 by means of the screw 4.

The container 11 of the injection device 101 of Figure 2 also comprises at is proximal end an outer radial rim 16, serving for example as a bearing point for the fingers of the user at the moment of injection. In the storage position of the injection device 101 according to the invention, as shown in Figure 2, the collar 5 is clipped onto the outer radial rim

16 of the container 11 by means of the radial projections 8 of its distal skirt 7 which entrap the outer radial rim 16. Likewise in this position, the collar 5 is connected to the piston rod 1 by means of the continuous web 9 of material.

Thus, if an unauthorized person attempts to gain access to the distal liquid through the proximal end of the container 11 by means of a needle which is sufficiently flexible to be curved, it is prevented from doing so by the continuous web 9 of material which forms an obstacle to the penetration of the needle, and moreover closes the possible angle for the passage of such a needle between the proximal transverse wall 3 and the inner walls of the container 11. In the case of a needle used to gain access to the liquid which would manage to pierce and to pass through the continuous web 9, the continuous web 9 would then be marked by the orifice left by the needle. The injection device would then be easily identified as having lost its integrity. Furthermore, since the possible angle for the passage of a needle is small and since the space "e" provided between the collar 5 and the elongate rod 2 of the piston rod 1 has a maximum value of 1 mm, the end of this needle would strike the elongate rod 2 so as to be lodged therein or would curve and follow the intersection of two branches 10. In the embodiment shown, the distal progression of the needle would then be stopped when the end of the needle reaches the rigid disc 20.

Furthermore, if an unauthorized person presses in the distal direction or by contrast pulls in the proximal direction on the distal transverse wall 3 in order to move the piston 15 with respect to the container 11 , the force that he must exert to achieve this aim causes the continuous web 9 of material to break, and this breakage then constitutes a clear indication for an authorized user that the injection device 101 has been forced or sabotaged. Thus, the continuous web 9 or material constitutes frangible connection means for connecting the collar 5 to the piston rod 1 ; in other words, this continuous web 9 of material is capable of breaking or fracturing when it is subjected to a force greater than or equal to the force necessary to move the piston 15, the remainder of the collar 5, that is to say the transverse wall 6, being moreover maintained immobile since this collar 5 is clipped onto the outer radial rim 16 of the container 11. In an embodiment of the invention which is not represented, the injection device according to the invention is packaged in a blister, that is to say within a thermoformed film of rigid plastic matching the overall outer shapes of the injection device. Figures 4 and 5 depict another embodiment of the piston rod 1 according to the invention. The references denoting the same elements as for Figures 1-3 have been kept. Thus, the piston rod 1 of Figure 4 comprises an elongate rod 2 having a cross section in the form of a cross with four branches 10 (see Figure 5). In this example, the collar 5 is made from the same material as that forming the elongate rod 2 of the piston rod 1. For example, the elongate rod 2 of the piston rod 1 and the collar 5 are made of thermoplastic material such as polypropylene. The collar 5 is connected to the piston rod by frangible connection means in the form, in the example represented, of four frangible discrete bridges 17, each discrete bridge 17 connecting the end of a branch 10 to the transverse wall 6 of the collar 5. In this embodiment also, the value "e" represents the distance between the collar 5 and the piston rod 1 , here the elongate rod 2. In the embodiment shown on this Figure, the value "e", in other words the distance between the collar 5 and the piston rod 1 , is constant on the entire periphery of the piston rod 1. In the storage position of a prefilled injection device 101 according to the invention used with the piston rod 1 of Figures 4 and 5, if a person attempts to gain access to the product contained in the container through the proximal end of the container, by means of a needle, he is prevented from doing so by the presence of the four discrete bridges 16 which leave only a small gap or space for the passage of such a needle between the collar 5 and the elongate rod 2 of the piston rod 1. Moreover, even if the needle used by the person attempting to force the injection device 101 can be curved, the presence of the discrete bridges 17 creates chicanes that the needle can only bypass with difficulty in order to reach as far as the product present in the container 11. Moreover, since the space "e" provided between the collar 5 and the rod 2 of the piston rod 1 has a maximum value of 1 mm, the end of this needle would strike the rod 2 in order to lodge therein or would curve and follow the intersection of two branches 10. In the embodiment shown, the distal progression of the needle would then be stopped when the end of the needle reaches the rigid disc 20. In an embodiment of the invention which is not represented, the injection device according to the invention is packaged in a blister, that is to say within a thermoformed film of rigid plastic matching the overall outer shapes of the device: the path that would then have to be followed by a needle to reach the product of the container is then made more difficult by the presence of the plastic film to be pierced, the latter constituting an additional required passage for the needle.

Finally, if the said person presses in the distal direction or even pulls in the proximal direction on the bearing surface of the piston rod 1 in order to move the piston with respect to the container, the force that he must exert to achieve this aim causes the discrete bridges 17 to break, and this breakage then constitutes a clear indication for an authorized user that the injection device 101 has been forced or sabotaged. Thus, the discrete bridges 17 constitute frangible connection means for connecting the collar 5 to the piston rod 1 ; in other words, these discrete bridges 17 are capable of breaking or fracturing when they are subjected to a force greater than or equal to the force necessary for moving the piston, the remainder of the collar 5, that is to say the transverse wall 6 being moreover maintained immobile, for example since it is clipped onto the outer radial rim 16 of the container 11. Thus, the piston rod according to the invention, when it is used with an injection device of the prefilled type, makes it impossible to gain access to the product contained in the said injection device from the proximal end of this injection device, in particular when the injection device is packaged within a blister-type packaging. Moreover, the piston rod according to the invention also makes it possible to provide a clear indication that the injection device according to the invention has been forced.

Claims

1. Piston rod (1) intended to be connected to a piston (15) of a container (11) of an injection device (101), the said piston rod (1) comprising at its proximal end a bearing surface (3) for allowing a user to exert a distal pressure on the said piston rod (1) when the latter is connected to the said piston (15), characterized in that the said piston rod (1) comprises a collar (5) situated distally with respect to the said bearing surface (3), the said collar (5) receiving the said piston rod (1) and being connected to the said piston rod (1) by frangible connection means (9; 17), said frangible connection means (9; 17) defining a space "e" between the collar (5) and the piston rod (1), the maximum value of which is less than or equal to 1 mm.

2. Piston rod (1) according to Claim 1 , characterized in that it is provided at its distal end with a rigid disc (20).

3. Piston rod (1) according to any one of Claims 1 to 2, characterized in that the said frangible connection means comprise a continuous web (9) of material provided between the said collar (5) and the said piston rod (1).

4. Piston rod (1) according to any one of Claims 1 to 2, characterized in that the said frangible connection means comprise at least one discrete bridge (17) of material provided between the said collar (5) and the said piston rod (1).

5. Piston rod (1) according to any one of Claims 1 to 4, characterized in that the said piston rod (1) and the said collar (5) are produced as a single part.

6. Piston rod (1) according to Claim 5, characterized in that the said part is produced by injection moulding of a thermoplastic material.

7. Piston rod (1) according to any one of Claims 1 to 6, characterized in that the said piston rod (1) comprises an elongate rod (2) having a cross section in the form of a cross having four branches (10).

8. Piston rod (1) according to Claims 4 and 7, characterized in that the end of each branch (10) is connected to the said collar (5) by at least the said discrete bridge (17).

9. Piston rod (1) according to any one of Claims 1 to 8, characterized in that the said collar (5) is provided with a distal skirt (7) provided on its inner wall with radial projections (8).

10. Injection device (101) comprising at least:

- a container (11) at least partially filled with a product (12) to be injected, the said container (11) comprising at its distal end an end-piece (13) intended to receive a needle, - a piston (15) housed within the said container (11), proximally with respect to the said product (12) and capable of moving distally within the said container (11 ) in order to expel the said product (12) through the distal end of the said container (11), characterized in that it additionally comprises a piston rod (1) according to any one of Claims 1 to 9, the said collar (5) being situated proximally at the proximal end of the said container (11) when the said piston rod (1) is connected to the said piston (15).

11. Injection device (101) according to Claims 9 and 10, characterized in that, the said proximal end of the container (11) being provided with an outer radial rim (16), the said collar (5) is clipped onto the said outer radial rim (16) by means of the said radial projections (8).

12. Injection device (101) according to Claim 10 or 11 , characterized in that it is packaged in a blister-type plastic packaging.