WO2018002044A1

WO2018002044A1 - Drug delivery device with drug differentiation feature

Info

Publication number: WO2018002044A1
Application number: PCT/EP2017/065843
Authority: WO
Inventors: Jesper Peter Windum; Arne Stjernholm MADSEN
Original assignee: Novo Nordisk A/S
Priority date: 2016-06-29
Filing date: 2017-06-27
Publication date: 2018-01-04

Abstract

A drug delivery device comprises a reservoir holding a given type of drug, a drug outlet, and a coding structure. A cap is adapted to be releasably secured to the drug delivery device to cover the drug outlet, the cap comprising a feedback structure adapted to engage the coding structure when the cap is removed from the drug delivery device. The cap comprises a housing with a wall opening and a clip portion having a free end with a protrusion protruding through the opening. The protrusion is configured to engage the coding structure of the drug delivery device to thereby generate a tactile and/or audible feedback pattern when the cap is removed from and/or secured to the drug delivery device.

Description

DRUG DELIVERY DEVICE WITH DRUG DIFFERENTIATION FEATURE

The present invention generally relates to medical drug delivery devices. In specific embodiments the invention relates to drug delivery devices adapted to generate a tactile and/or audible feedback pattern when operated by the user.

BACKGROUND OF THE INVENTION

In the disclosure of the present invention reference is mostly made to the treatment of diabetes by delivery of insulin-containing drugs, however, this is only an exemplary use of the present invention.

Drug delivery devices (typically for subcutaneous injection) have greatly improved the lives of patients who must self-administer drugs and biological agents. Drug injection devices may take many forms, including simple disposable devices that are little more than an ampoule with an injection means or they may be highly sophisticated electronically controlled instru- ments with numerous functions. Regardless of their form, they have proven to be great aids in assisting patients to self-administer injectable drugs and biological agents. They also greatly assist care givers in administering injectable medicines to those incapable of performing self-injections. In particular pen-style injection devices have proven to provide an accurate, convenient, and often discrete, way to administer drugs and biological agents, such as insulin. Modern devices have become more sophisticated and often include diverse and robust functions, such as memories for remembering time and amount of last dose, as well as, in the case of insulin devices, blood glucose monitors. While pen-style injection devices are typically cylindrically shaped with a needle protruding from the most distal portion of one end of the device, some devices have other shapes with the needle no longer protruding from the most distal part of an end of the device, e.g. Innovo® and InnoLet® from Novo Nordisk A/S, Bagsvaerd, Denmark. Typically injection devices use a pre-filled cartridge containing the medication of interest, e.g. 1.5 or 3.0 ml of insulin or growth hormone. The cartridge is typically in the form of a generally cylindrical transparent ampoule with a needle pierceable septum at one end and an opposed piston designed to be moved by the dosing mechanism of the injection device. The injection devices generally are of two types: "Durable" devices and "disposable" devices. A durable device is designed to allow a user to replace one cartridge with another cartridge, typically a new cartridge in place of an empty cartridge. In contrast, a disposable device is provided with an imbedded cartridge which cannot be replaced by the user without damaging or destroying the device; when the cartridge is empty the entire device is intended to be discarded. Most injection devices are provided with a releasable pen cap covering the cartridge and the needle mount portion (see below), this allowing the user to inspect the content of the cartridge by removing the cap.

Often injection devices are provided as a system or family of devices containing different types of drugs, e.g. as known from WO 2004/069314. This application discloses a system of substantially identical injection devices, each individual injection device comprising a housing accommodating an ampoule containing drug sufficient for a number of injections and a dose setting mechanism by which a predetermined dose size can be set, and wherein each of the plurality of injection devices has a different predetermined dose size. The difference in the predetermined dose sizes can in one embodiment be based on the drug in the devices having different strength.

People suffering from diabetes are often treated with multiple daily injections in a regimen comprising one or two daily injections of long acting insulin to cover the basal requirement supplemented by bolus injections of short or rapid acting insulin to cover requirements related to meals.

A user will therefore often require two different injection devices, one containing the long acting insulin and another containing the short or rapid acting insulin. Often these injection devices have different colour indications to inform the user of the kind of insulin contained in the injection device. For example, the FlexPen® system offered by Novo Nordisk comprises pens for long and short acting insulins as well as for mixed insulin, the bodies and caps being identical with colour markings on the main body to differentiate the two types of insulin. In the SoloStar® system offered by Sanofi-Aventis the pens for long and short acting insulins have differently coloured bodies as well as caps. In addition these injection devices can be provided with tactile means such as a mechanical coding informing the user of the kind of insulin contained in the injection device.

WO 201 1/124634 discloses a coded cap for use with a drug delivery device as well as a drug delivery device comprising such a cap. Although the prior art discloses a number of solutions of how to differentiate similar or otherwise identical drug delivery devices containing different kinds of drugs, there is still a need for drug delivery devices which in a simple and effective manner provides a strong identification of the kind of drug contained in a specific device, this reducing the risk of a user inadvertently taking the incorrect kind of drug. Having regard to the above, it is an object of the present invention to provide a drug delivery device, system and components therefore which in a simple and cost-effective manner reduces the likelihood of a user taking the incorrect kind of drug.

DISCLOSURE OF THE INVENTION

In the disclosure of the present invention, embodiments and aspects will be described which will address one or more of the above objects or which will address objects apparent from the below disclosure as well as from the description of exemplary embodiments.

Thus, in accordance with a first aspect a drug delivery assembly is provided, the assembly comprising a drug delivery device and a cap. The drug delivery device comprises a reservoir holding a given type of drug, a drug outlet, and a coding structure. The cap is adapted to be releasably secured to the drug delivery device to cover the drug outlet, and comprises a feedback structure adapted to engage the coding structure when the cap is mounted on and/or removed from the drug delivery device, wherein the cap comprises a housing with a wall opening and a clip portion having a free end with a protrusion protruding through the opening and being configured to engage the coding structure of the drug delivery device to thereby generate a tactile and/or audible feedback pattern when the cap is mounted on and/or removed from the drug delivery device. By this arrangement a simple and reliable means of providing coded feedback to the user of a drug delivery assembly is provided in a cost-effective way.

Although the term "clip" in the present context is considered to be a well-known technical term to the skilled person, the above-mentioned clip portion may be defined as having an elongate configuration with a length defined between its free end and the attachment to the cap housing, the clip portion having a width smaller than the length. The clip portion is normally arranged for most of its length with a distance to the portion of the cap housing to which it is mounted or formed integrally with, this forming a gap allowing e.g. a piece of clothing to be introduced into the gap. Alternatively, a clip could be designed without a gap. The cap wall may be circumferential defining an interior space with the clip protrusion protruding through the opening and into the interior space.

In an exemplary embodiment the drug delivery device comprises a cartridge holder portion (or just cartridge holder) accommodating at least a portion of the reservoir, the coding structure being arranged on the cartridge holder and being covered by a secured cap. The cartridge holder may be adapted to be non-removably attached to a drug delivery device main portion to form a disposable drug delivery device, or it may be adapted to be removably attached to a drug delivery device main portion to form a durable drug delivery device. In the latter case the cartridge holder may be in the form of a disposable cartridge holder unit comprising a drug-filled cartridge non-removably mounted therein.

The coding structure may comprise a plurality of protrusions and/or indentations sequentially engaging the clip protrusion when the cap is mounted on and/or removed from the drug de- livery device to thereby create the feedback pattern.

The cap opening and the clip protrusion may be configured to engage each other to close the opening when the cap is secured to the drug delivery device, e.g. by chamfered surfaces engaging each other or by a circumferential line of contact, this help preventing that e.g. dust, dirt or liquid will enter the cap interior during use of the pen. Indeed, this will in most cases also be the case when the cap has been removed from the drug delivery device. The clip protrusion may be biased into engagement with the opening, this enhancing the closure properties. The reservoir may have a general tubular configuration defining a reference axis, the cap being adapted to be mounted on the drug delivery device along the reference axis with the coding structure adapted for linear axial movement between the cap and the coding structure. Alternatively the coding structure may be arranged to allow for a rotational or helical movement of the cap relative to the code structure. The cap and the drug delivery device may be provided with cooperating orientation means for rotationally orient the clip protrusion and the coding structure relatively to each other when the cap is mounted on the drug delivery device.

In a further aspect a cap adapted to be releasably secured to a drug delivery device to cover a drug outlet is provided, the cap comprising a housing with a circumferential wall defining an interior space, an opening formed in the wall, a clip portion having a free end with a protrusion protruding through the opening and into the interior space.

The cap opening and the clip protrusion are configured to sealingly engage each other when the cap is in an initial state, e.g. not yet mounted on a structure.

The clip portion may be flexible to allow the protrusion to be moved relative to the opening. In an alternative configuration the clip portion may be "stiff' and the clip holding action may be provided by a distally mounted "pinch" member, e.g. a flexible member or a spring-biased member, the latter then also forming the clip protrusion. As a further alternative a stiff clip portion may be attached to a clip base by a hinge, the hinge providing a pinching force.

In a yet further aspect a drug delivery system comprising first and second drug delivery devices as well as a cap is provided, the first drug delivery device comprising a first reservoir holding a first type of drug, a first drug outlet, and a first coding structure. The second drug delivery device comprises a second reservoir holding a second type of drug, a second drug outlet, and a second coding structure. The cap is adapted to be releasably secured to either of the first and second drug delivery device to cover the corresponding drug outlet, and comprises a feedback structure adapted to engage the coding structure when the cap is mounted on and/or removed from either of the drug delivery devices. The first coding structure is configured to create a first feedback pattern indicative of the first type of drug when the cap is secured to and/or removed from the first drug delivery device, and the second coding structure is configured to create a second feedback pattern indicative of the second type of drug when the cap is secured to and/or removed from the second drug delivery device. The drug delivery device may e.g. be in the form of a pre-filled drug delivery device or in the form of a combination of a pre-filled cartridge holder unit and a durable drug delivery device main portion.

By this arrangement a simple and reliable means of providing coded feedback to the user of a drug delivery system is provided in a cost-effective way as the code engaging cap can be used for either of the devices in the system.

In a further aspect a drug delivery system is provided comprising a drug delivery device main portion, a cap, a first drug unit and a second drug unit. The first drug unit comprises a first reservoir holding a first type of drug, a first drug outlet, a first coding structure, and a drug unit coupling structure. The second drug unit comprises a second reservoir holding a second type of drug, a second drug outlet, a second coding structure, and a drug unit coupling structure. The drug delivery device main portion comprises a main portion coupling structure adapted to cooperate with a drug unit coupling structure allowing a drug unit to be mounted in an operational state, and an expelling mechanism adapted to expel an amount of drug from a drug unit mounted in the operational state.

The cap is adapted to be releasably secured to either of the first and second drug unit or the drug delivery device main portion to cover the corresponding drug outlet, and comprises a feedback structure adapted to engage a coding structure when the cap is mounted on and/or removed from either of the drug units, wherein the first coding structure is configured to create a first feedback pattern indicative of the first type of drug when the cap is secured to cover and/or removed to un-cover the first drug outlet, and the second coding structure is configured to create a second feedback pattern indicative of the second type of drug when the cap is secured to cover and/or removed to un-cover the first drug outlet.

By this arrangement a simple and reliable means of providing coded feedback to the user of a drug delivery system is provided in a cost-effective way as the code engaging cap as well as the drug delivery device main portion can be used for either of the drug units in the system. As indicated above, the cap may be designed to engage coupling means arranged on either the drug units per se or the drug delivery device main portion, this including the cap engaging coupling structures on both a drug unit and the drug delivery device main portion.

In exemplary embodiments each drug delivery device or drug unit comprises a cartridge holder portion accommodating at least a portion of the reservoir, the coding structure being arranged on the cartridge holder portion and being covered by a secured cap. The feedback may audible and/or tactile. Each coding structure may comprise a plurality of protrusions sequentially engaging the feedback structure when the cap is removed from a drug delivery device to thereby create the feedback pattern. The cap may comprise a tubular housing with a radial opening in a circumferential wall and a clip portion having a free end with a protrusion protruding through the opening and being configured to engage the coding structure of a drug delivery device to thereby generate a feedback pattern when the cap is mounted and/or removed from a drug delivery device. The cap may be designed to be secured to a cartridge holder and/or the device main portion. The cap and each drug delivery device may comprise cooperating means for rotationally orient the cap relatively to a drug delivery device as the cap is secured thereto. The above-described drug delivery devices may be in the form of drug injection devices intended for subcutaneous delivery of an amount of a liquid drug formulation. Such a drug delivery device may have a general pen-shaped configuration and be adapted to expel one or more doses of a pre-set dose size, or it may comprise an expelling mechanism allowing a user to set a desired dose of drug to be expelled. The device may be pre-filled comprising a cartridge not intended to be removed from the device when emptied. Alternatively the drug delivery device may be in the form of an inhalation device comprising aerosol generating means. Such a device may comprise an outlet in the form of a mouthpiece and a protective cap adapted to be mounted on the mouthpiece.

As used herein, the term "drug" is meant to encompass any drug-containing formulation capable of being administered to a patient in a controlled manner, e.g. passed through a delivery means such as a cannula or hollow needle, such as a liquid, solution, gel or fine suspen- sion, or passed through a nozzle or mouthpiece as an aerosol or powder. Representative drugs include pharmaceuticals such as peptides (e.g. insulins, insulin containing drugs, GLP- 1 containing drugs as well as derivates thereof), proteins, and hormones, biologically derived or active agents, hormonal and gene based agents, nutritional formulas and other substances in either solid (dispensed), powder or liquid form. In the description of the exemplary em- bodiments reference will be made to the use of insulin containing drugs or drugs having insulin-like effects. Correspondingly, the term "subcutaneous" injection is meant to encompass any method of transcutaneous delivery to a subject.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be further described with reference to the drawings, wherein fig. 1A shows a pen device,

fig. 1 B shows the pen device of fig. 1 A with the pen cap removed,

fig. 2 shows a cap and a coded cartridge holder for a pen device as shown in fig. 1A, and fig. 3 shows in a longitudinal cross-section a cap mounted on a coded cartridge holder.

In the figures like structures are mainly identified by like reference numerals.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

When in the following terms such as "upper" and "lower", "right" and "left", "horizontal" and "vertical" or similar relative expressions are used, these only refer to the appended figures and not to an actual situation of use. The shown figures are schematic representations for which reason the configuration of the different structures as well as there relative dimensions are intended to serve illustrative purposes only. Before turning to embodiments of the present invention per se, an example of a prefilled drug delivery will be described, such a device providing the basis for the exemplary embodiments of the present invention. Although the pen-formed drug delivery assembly 100 shown in figs. 1A and 1 B may represent a "generic" drug delivery device, the actually shown device is a FlexTouch® prefilled drug delivery pen as manufactured and sold by Novo Nordisk A S, Bagsvaerd, Denmark. A more detailed description of such a device can be found in e.g. WO 2014/161952 which is hereby incorporated by reference.

The pen assembly 100 comprises a cap part 1 10 and a main drug delivery device (or part) 105 having a proximal body or drive assembly portion with a housing 101 in which a drug ex- pelling mechanism is arranged or integrated, and a distal cartridge holder 120 in which a drug-filled transparent cartridge 130 with a distal drug outlet in the form of a needle- penetrable septum 131 is arranged and retained in place by a non-removable cartridge holder attached to the proximal portion, the cartridge holder having openings allowing a portion of the cartridge to be inspected as well as distal coupling means 125 allowing a needle assem- bly to be releasably mounted. The cartridge holder 120 comprises proximal coupling means 121 adapted to engage corresponding coupling means arranged on the cap interior surface. Alternatively, the cap may be designed to engage coupling means arranged on the main device distal portion. The cartridge is provided with a piston driven by a piston rod forming part of the expelling mechanism and may for example contain an insulin, GLP-1 or growth hor- mone formulation. A proximal-most rotatable dose setting member 180 serves to manually set a desired dose of drug shown in display window 102 and which can then be expelled when the button 190 is actuated. Depending on the type of expelling mechanism embodied in the drug delivery device, the expelling mechanism may comprise a spring as in the shown embodiment which is strained during dose setting and then released to drive the piston rod when the release button is actuated. Alternatively the expelling mechanism may be fully manual in which case the dose member and the actuation button moves proximally during dose setting corresponding to the set dose size, and then is moved distally by the user to expel the set dose, e.g. as in a FlexPen® manufactured and sold by Novo Nordisk A/S. Although fig. 1 shows a drug delivery device of the prefilled type, i.e. it is supplied with a pre- mounted cartridge and is to be discarded when the cartridge has been emptied, in alternative embodiments the drug delivery device may be designed to allow a loaded cartridge to be replaced, e.g. in the form of a "rear-loaded" drug delivery device in which the cartridge holder is adapted to be removed from the device main portion, or alternatively in the form of a "front- loaded" device in which a cartridge is inserted through a distal opening in the cartridge holder which is non-removable attached to the main part of the device.

Turning to figs. 2 and 3 an exemplary embodiment of the invention will be illustrated. Fig. 2 shows a cap part 210 in combination with a cartridge holder 220 in which a generally tubular drug-filled cartridge 230 with a septum outlet 231 is arranged. The cap has a general tubular configuration with a closed distal end and an open proximal end adapted to axially receive the cartridge holder. The cartridge holder 220 generally corresponds to the cartridge holder 120 of the above-described drug delivery device and thus comprises a proximal coupling portion 229 adapted to non-removably engage a device housing portion. Alternatively, the cartridge holder may be in the form of a disposable unit comprising a non-removable drug-filled cartridge and coupling means allowing the cartridge to be mounted on and released from a durable device housing portion. The cartridge may be held in place by snap means arranged to grip the cartridge, e.g. engaging the neck portion and/or the distal edge portion.

The cartridge holder has a general tubular configuration defining an axis of reference. The cartridge holder comprises on its distal portion a series of transversely extending grooves 222 forming a series of "protrusions" 223 there between, the grooves and protrusions forming a specific coding structure which for a pre-filled drug delivery device can be linked to the given drug contained in the cartridge. The cap 210 is adapted to be releasably secured to the cartridge holder 220 to cover the drug outlet. The cap comprises a generally tubular housing portion 21 1 with a radial side opening (see fig.3) as well as a flexible clip portion 215 having a free end 216 with a ridge- formed clip protrusion 217 protruding through the opening and being configured to engage the coding structure on the cartridge holder to thereby generate a both tactile and audible feedback pattern as the flexible clip portion moves "up and down" when the cap is mounted on and removed from the drug delivery device. To assure that the clip protrusion mates with the coding structure the cap and cartridge holder may be provided with an orientation structure (not shown) that assures that the cap can only be mounted and move axially with the correct rotational orientation, e.g. by means of a projection on the cap housing inner surface being received in a correspondingly formed groove on the cartridge holder. Such a grove may e.g. be arranged opposite the coding structure and may also comprise a distal "funnel inlet" to help rotate the cap correctly when it is mounted on the cartridge holder.

Fig. 3 shows the cap fully mounted and secured on the cartridge holder with the clip protru- sion arranged in the proximal-most transverse groove. This engagement may be used to provide a coupling arrangement between the cap and the cartridge holder securing the cap both rotationally and axially on the cartridge holder. Alternatively or in addition a "traditional" snap engagement may be provided between the two structures, e.g. corresponding to the proximal-most inner surface of the cap housing.

The clip protrusion 217 and the cap side opening 212 may be formed and configured to engage each other when the cap is mounted in its secured position on the cartridge holder to close (or seal) the opening, this help preventing that e.g. dust, dirt or liquid will enter the cap interior during use of the pen. For such a design the cap and cartridge holder should be pro- vided with mating coupling means allowing the clip protrusion to be arranged without engagement with the cartridge holder with the cap in its fully secured position. In order to allow the clip protrusion to engage the cap side opening with a certain bias the cap may be assembled from two components, i.e. a clip portion and a housing portion, this as shown in fig. 3. More specifically, fig. 3 shows the cap comprising a tubular housing portion 21 1 with a side opening 212 to which is attached a distal plug component 218 closing the housing distal end and also forming the clip portion 215. The two components may be attached to each other by means of e.g. adhesives, snap locks or welding.

The cartridge holder 220 comprises a coding structure with a plurality of identically shaped transversal grooves (here: 10) arranged with a uniform distance between each groove. With the clip protrusion 216 initially arranged in the proximal-most coding groove the clip protrusion and thereby the flexible clip 215 will be moved up and down as the cap is removed from the cartridge holder in a distal direction. If the user holds a finger on the clip as the cap is removed from the cartridge holder he or she will feel a "vibration" whereas if the clip is not touched during cap removal a clicking sound be heard more clearly. In either case a feedback which is unique for the given cartridge holder (and thus the contained drug) is felt and/or heard.

The shown example of a coding structure having 10 grooves (thereby providing 10 "protrusions") may indicate e.g. a long-acting insulin formulation whereas a coding structure having e.g. 3 grooves may be indicate a fast-acting insulin. However, the coding structure and the individual structures can be varied in numerous ways. For example, the grooves and/or protrusions may have any desired shape considered to achieve a distinct sound and/or feel, the individual code structures may be identical or non-identical, the number of code structures just as the spacing between the individual code structures may vary.

With reference to figs. 2 and 3 a separate tubular cartridge holder adapted to be mounted on a corresponding pen main body was described, however, in an alternative embodiment the majority of the cartridge receiving structure of the pen device may be formed integrally with the main pen housing, the cartridge being inserted from the distal end and held in place by a distal closure member.

The above-described clip portion is in the form of a "traditional" clip allowing a pen device with the cap mounted to be attached to e.g. a shirt pocket. However, the clip portion may be optimized for the described code feedback functionality, e.g. having a reduced size making it less suitable, or even unsuitable, for its traditional purpose.

With reference to figs. 2 and 3 a coding structure adapted for linear axial movement between the cap and the coding structure was described, however, in alternative embodiments the coding structure may be arranged to allow for a rotational or helical movement of the cap rel- ative to the code structure.

As appears, the unique part of the above-described code feature is the cartridge holder and not necessarily the cap which may be identical for a number of different pen devices with different drugs and thus codes. Correspondingly, an exemplary system comprises a first and a second drug delivery device, the first drug delivery device comprising a first reservoir holding a first type of drug, a first drug outlet, and a first coding structure. The second drug delivery device comprises a second reservoir holding a second type of drug, a second drug outlet, and a second coding structure. The system further comprises a cap adapted to be releasably secured to either of the first and second drug delivery devices to cover the corresponding drug outlet, and comprising a feedback structure adapted to engage the coding structure when the cap is mounted on either of the drug delivery devices. Indeed, normally each device will be provided with its own cap, albeit of identical design. In such a system the first coding structure is configured to create a first feedback pattern indicative of the first type of drug when the cap is secured to the first drug delivery device, and the second coding struc- ture is configured to create a second feedback pattern indicative of the second type of drug when the cap is secured to the second drug delivery device. The drug delivery devices and the cap for such a system may be designed as described above for the assembly of figs. 2 and 3. If desired, the above-described cap could be provided with a further coding system allowing a given cap to be provided in a specific colour corresponding to the type of pen device (and thus type of drug formulation) for which it is intended. For example, a first drug delivery device with a cartridge holder in a first colour is provided, the cartridge holder comprising a first coding structure of the above-described tactile/ audible type for a first type of drug, e.g. a fast-acting insulin formulation, as well as a first secondary coding structure allowing only a correspondingly coded first cap having the first colour to be attached. A second drug delivery device with a cartridge holder in a second colour is provided, the cartridge holder comprising a second coding structure of the above-described tactile/audible type for a second type of drug, e.g. a long-acting insulin formulation, as well as a second secondary coding structure allowing only a correspondingly coded second cap having the second colour to be attached. Alternative or in addition the physical configuration of the cap may be varied, e.g. the clip may be designed to provide a desired feedback when utilized in combination with a specific code design. A coding feature for such a secondary coding system is described in greater detail in WO 201 1/ 032883.

In the above-described examples the tactile/audible coding structure was described for use with pre-filled drug delivery devices or, as an alternative, a pre-filled cartridge unit, however, the coding feature may also be utilized for a durable device. For example a durable device may be provided in two versions with different code structures, this allowing the devices to be used for e.g. long and fast-acting insulin. Indeed, the user would have to make sure that a given cartridge loaded into the cartridge holder would correspond to the coding structure.

In an alternative embodiment a system comprising two or more inhalation devices is provided, each device comprising aerosol generating means, an outlet in the form of a mouthpiece and a protective cap adapted to be mounted on the mouthpiece, e.g. as known from US 7,278,425 which is hereby incorporated by reference. In such a system the corresponding coding and feedback structures may be arranged on the mouthpiece respectively the cap. For such a system the feedback generating clip may be designed primarily for this purpose and thus not be suitable to serve as a traditional "shirt pocket clip". In the above description of the preferred embodiments, the different structures and means providing the described functionality for the different components have been described to a degree to which the concept of the present invention will be apparent to the skilled reader. The detailed construction and specification for the different components are considered the object of a normal design procedure performed by the skilled person along the lines set out in the present specification.

Claims

1. A cap (210) adapted to be releasably secured to a drug delivery device (105) to cover a drug outlet, the cap comprising:

a housing (21 1 ) with a circumferential wall defining an interior space,

- an opening (212) formed in the wall,

a clip portion (215) having a free (216) end with a protrusion (217) protruding through the opening and into the interior space.

2. A cap as in claim 1 , wherein in an initial state the opening and the clip protrusion are configured to engage each other to close the opening.

3. A cap as in claim 1 or 2, wherein in an initial state the clip protrusion is biased into engagement with the opening.

4. A cap as in any of claims 1-3, wherein the clip portion (215) is flexible to allow the protrusion to be moved relative to the opening.

5. A drug delivery assembly (100) comprising a cap as in claim 1 in combination with a drug delivery device, the drug delivery device (105) comprising:

- a reservoir (230) holding a given type of drug,

a drug outlet (231 ), and

a coding structure (225), the cap (210) being adapted to be releasably secured to the drug delivery device to cover the drug outlet, wherein:

the protrusion (217) is configured to engage the coding structure (225) of the drug delivery device to thereby generate a tactile and/or audible feedback pattern when the cap is mounted on and/or removed from the drug delivery device.

6. A drug delivery assembly as in claim 5, wherein the drug delivery device comprises a cartridge holder portion (220) accommodating at least a portion of the reservoir (230), the coding structure (225) being arranged on the cartridge holder portion and being covered by a secured cap.

7. A drug delivery assembly as in claim 5 or 6, wherein the coding structure comprises a plurality of protrusions (223) and/or indentations (222) sequentially engaging the clip protrusion (217) when the cap is mounted on and/or removed from the drug delivery device to thereby create the feedback pattern.

8. A drug delivery assembly as in any of claims 5-7, wherein the opening (212) and the clip protrusion (217) are configured to engage each other to close the opening when the cap is secured to the drug delivery device.

9. A drug delivery assembly as in any of claims 5-8, wherein in an initial state the clip protrusion is biased into engagement with the opening.

10. A drug delivery assembly as in any of claims 5-9, wherein the clip portion (215) is flexible to allow the protrusion to be moved relative to the opening.

1 1 . A drug delivery assembly as in any of claims 5-10, wherein the reservoir (230) has a general tubular configuration defining a reference axis, the cap (210) being adapted to be mounted on the drug delivery device along the reference axis.

12. A drug delivery assembly as in any of claims 5-1 1 , wherein the cap and the drug delivery device comprises cooperating orientation means for rotationally orient the clip protrusion and the coding structure relatively to each other when the cap is mounted on the drug delivery device.

13. A drug delivery system comprising a cap as in claim 1 in combination with a first and a second drug delivery device (105), the first drug delivery device comprising:

a first reservoir holding a first type of drug,

a first drug outlet, and

a first coding structure (225), the second drug delivery device comprising:

a second reservoir holding a second type of drug,

a second drug outlet, and

a second coding structure (225), the cap (210) being adapted to be releasably secured to either of the first and second drug delivery devices to cover the corresponding drug outlet, wherein:

- the first coding structure is configured to create a first feedback pattern indicative of the first type of drug when the cap is secured to and/or removed from the first drug delivery device, and

the second coding structure is configured to create a second feedback pattern indicative of the second type of drug when the cap is secured to and/or removed from the second drug delivery device.

14. A drug delivery system as in claim 13, wherein each drug delivery device comprises a cartridge holder portion (220) accommodating at least a portion of the reservoir (230), the coding structure being arranged on the cartridge holder portion and being covered by a se- cured cap.

15. A drug delivery assembly as in claim 13 or 14, wherein the opening (212) and the clip protrusion (217) are configured to engage each other to close the opening when the cap is secured to a drug delivery device.

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