Cartridge holder for a drug delivery device

Abstract

The present invention relates to a housing (40) of a drug delivery device for applying a liquid drug from a barrel (30). The housing (40) includes a recessed portion (48) for accommodating the proximal portion of the barrel (30). The housing further includes a deformable component (41.1, 41.2) arranged inside the recessed portion (48), and the deformable component (41.1, 41.2) includes a proximal end attached to the housing (40) and a distal end (52) movable in the recessed portion (48). The component (41.1, 41.2) can be deformed from a non-deformed state to a deformed state by the displacement of the distal end (52), wherein, in the deformed state, the component (41.1, 41.2) is suitable for limiting the movement of the barrel (30) relative to the housing (40) in the longitudinal direction. The component (41.1, 41.2) further includes an arched portion (42, 43), and, in the deformed state, the arched portion (42, 43) is both elastically and plastically deformed.

Description

Technical Field

[0001] The present invention relates to a drug delivery device for delivering, administering, dispensing, injecting or infusing substances and / or liquids such as insulin preparations or hormone preparations. The present invention is separated from a housing and a cartridge holder connectable to the housing for holding a cartridge in the housing and cartridge holder. Background Art

[0002] There are a wide variety of diseases that require conventional management by parenteral subcutaneous or intramuscular administration of drugs or medicaments, and many drug delivery devices have been developed to support patients in accurately and controllably delivering an amount of drug during self-administration.

[0003] Injection devices for self-administration generally include a metering and dispensing mechanism that allows a user to measure a desired dose and then administer or dispense the measured dose. The dispensing mechanism includes a piston rod that is movable relative to the housing of the injection device. The piston rod is adapted to move a stopper inside the barrel in a distal direction so as to dispense the drug through the distal opening of the barrel.

[0004] Injection device further comprises the barrel that comprises liquid medicine or medicament.Barrel is usually held by barrel holder and the housing of the injection device that holds dosing and distribution mechanism.In order to keep barrel, the distal part of barrel is contained in the sleeve-shaped barrel holder, and the proximal part of barrel is contained in the recessed part of housing.During assembly, barrel or first is inserted in the recessed part of housing with its proximal part, or barrel first is inserted in the barrel holder with its distal part.Subsequently, barrel holder is connected with the distal end of housing with its proximal end.For dosing and distribution accuracy, it is important that rigidly and accurately barrel is kept particularly axially or in distribution direction relative to housing and piston rod.

[0005] The member that is used to be retained in the housing by tube is known in the art.For example, US 9867945 discloses a kind of tube retainer, and this tube retainer has the tongue that can move inwards and outwards on the proximal part of retainer.The movable tongue comprises the protrusion that is suitable for engaging with the proximal edge portion of tube and is directed inwards.During tube is inserted in the retainer, when tube is inserted, the tongue is bent outwards elastically and flexes backwards.Therefore, under assembled state, tube can be clamped between the distal end stop face and the protrusion of retainer, so that tube is fastened with respect to tube retainer against the displacement to the distal side and the displacement to the proximal side.

[0006] US 9149580 discloses a tube holder, which includes a tensioning member connected to a compression spring positioned at a shoulder portion of a bottleneck body of the tube. The tube holder is further equipped with at least one counter-bearing element adapted to provide a proximal stop for the tube. Therefore, the tube can be effectively clamped between the tensioning member and the counter-bearing element.

[0007] US 2007 / 0021718 discloses a retaining member for a barrel comprising a spring inserted into a recessed portion of a housing of a pen injector. The proximal end of the spring is retained in the bottom of the recessed portion by a snap-fit ​​connection. When the barrel is inserted into the recessed portion with its proximal portion, the spring is compressed. In the assembled state, the compressed spring retains the barrel and biases the barrel to the distal inner wall of the barrel holder. Thus, the barrel is axially retained relative to the housing and the barrel holder.

[0008] These prior art approaches suffer from the fact that when the tube is inserted into a housing that may be unintentionally enlarged, the retaining member for retaining the tube relative to the housing may apply a biasing force or retaining force to the tube. If the tube is longer than expected (e.g., due to manufacturing tolerances), or if the tube is deeply inserted into the housing during assembly, and the biasing element is thus overly compressed, such a high retaining force may occur. If the retaining force is too high, the tube may be damaged or even broken. On the other hand, if the retaining force is too low, the tube may move within the housing, particularly after a storage period when material relaxation has occurred. Summary of the invention

[0009] It is therefore an object of the present invention to reliably and accurately retain a cartridge relative to a housing of a drug delivery device, or more generally to provide an alternative retaining member that is easy to manufacture with improved assembly capabilities.

[0010] This object is achieved by a housing for a cartridge unit for a drug delivery device according to the independent claims.Preferred embodiments are evident from the dependent patent claims.

[0011] According to the present invention, the housing for a drug delivery device for applying a liquid drug from a barrel includes a recessed portion for accommodating at least the proximal portion of the barrel. The recessed portion has an axis defining a longitudinal direction. The housing further includes a deformable component arranged inside the recessed portion, wherein the deformable component includes: a proximal end, which is attached to the housing, particularly to the sidewall of the recessed portion; and a distal end, which can be moved relative to the housing and relative to the sidewall in the recessed portion. The component can be deformed from a non-deformed state or an initial state to a deformed state by the displacement of the distal end. In the deformed state, the component is suitable for limiting the movement of the barrel present in the recessed portion relative to the housing in the longitudinal direction, particularly the proximal movement. The component includes a first arched portion between the proximal end and the distal end in the non-deformed state and the deformed state. In the deformed state, the first arched portion is both elastically and plastically deformed.

[0012] For initial assembly, tube must be inserted into the drug delivery device, and the proximal part of tube must be inserted into the recessed part of the housing of drug delivery device. During the period when tube is inserted into the recessed part, parts are deformed from non-deformed state to deformed state. Parts can be deformed by the displacement of the distal end. When tube is inserted into the recessed part, the distal end is preferably displaced by the proximal end of tube. When tube has been inserted into the final axial position entering the recessed part, the arched part is elastically deformed and plastically deformed simultaneously. Under this deformed state, the housing with this part is suitable for limiting the movement of tube relative to the housing along the proximal longitudinal direction. In addition, if tube is inserted into its final axial position, then this part together with tube holder or any corresponding element connected to the distal end of housing is suitable for keeping tube relative to housing, so that tube can no longer move relative to housing.

[0013] During the insertion of tube, the resistance or reaction force applied by the deformed parts act on the proximal end and act on the edge portion of tube in particular.When tube was not adjacent to these parts, under non-deformed state, there was no resistance.During tube being inserted into recessed portion, this force occurs at least in the first part and is increasing continuously, because the arch of these parts is deformed, and some parts of these parts are compressed.When the insertion of tube is completed and these parts are in its deformed state, there is still the force acting on the tube applied by these parts, because, under deformed state, these parts are not only deformed plastically, but also deformed elastically.

[0014] Deformable components are suitable for limiting the movement of tube in the recessed portion relative to the housing in the longitudinal direction. Therefore, the tube can be maintained in the final axial position of the pre-defined in the recessed portion or in the final axial range of the pre-defined relative to the housing. Due to the reason of the arched components, the force progression related to the deflection or deformation path during the deformation of the arched portion can be designed optimally. For example, the arched portion can be designed to make the force progression almost linear or the force progression follows a suitable mathematical function. Thus, the force acting on the tube can be well predicted. Therefore, parts are suitable for reliably limiting the axial movement of the inserted tube. In the assembled state, when the corresponding element (for example, the tube holder) is installed to the housing, the tube can be reliably and accurately maintained so that the tube resists the displacement to the far side and the displacement to the proximal side and is fastened.

[0015] Since the forces acting on the cartridge can be adjusted well by designing the component in the form of an arch, the inserted cartridge can be held with a predefined force within a predefined force range. This can be useful in order to be able to hold cartridges of different lengths (which may be caused by manufacturing tolerances). Thus, the arch can be designed so that short cartridges as well as long cartridges can be optimally held relative to the housing by the deformable component.

[0016] The elastic deformation of the arch causes a force acting on the proximal end of the inserted cartridge in a distal and longitudinal direction. The deformed arch biases the cartridge in a distal direction against a stop element in the cartridge holder or any corresponding element in the assembled state.

[0017] During storage, material relaxation may occur. Due to the elastic deformation of the arched portion, there is still a residual force acting on the barrel, and even if the initial force is reduced due to material relaxation, the movement of the barrel can be reliably restricted.

[0018] In addition to the elastic deformation, in the deformed state, the component is further deformed plastically so that further movement of the barrel is limited by the component. The effect of the plastic deformation is that, depending on the design of the arch, the force applied by the component on the barrel can be limited to a certain maximum value. Thus, the plastic deformation of the component can limit the applied (reaction) force acting on the barrel and thus prevent damage or even breakage of the barrel.

[0019] In the assembled state, when the retaining member (e.g., cartridge holder) is installed, the cartridge can no longer move, or the cartridge can only move within a very limited range (e.g., a few micrometers) relative to the housing and any dosing element (e.g., a plunger rod accommodated in the housing), thereby ensuring the accuracy of dosing and dispensing.

[0020] In a preferred embodiment, the sleeve-shaped tube holder with the recessed portion that is suitable for accommodating the distal portion of tube is installed to housing, so that tube is installed in the drug delivery device.Preferably, the opening of the recessed portion of tube holder slides on the distal end of tube.As mentioned above, tube is inserted into the housing with its proximal end.Alternatively, as mentioned above, tube is first inserted in the tube holder with its distal portion, and, then the proximal portion of tube is inserted into the housing.In two modifications, the proximal end of tube holder is then for example fixed to the distal end of housing by snap fit connection.Tube is thereby kept relative to the housing inside the drug delivery device by tube holder and housing.

[0021] Plastic deformation means that the deformation is irreversible and thus remains even after the applied force is removed. Elastic deformation means that the deformation is recoverable, since the deformation disappears after the applied force is removed.

[0022] The term "arched portion" means that the component has a curved shape between the proximal end and the distal end. The arch or curved shape may form an arc in the range of, for example, between 30° and 190°, preferably between 70° and 120°. The arch may be directed in any direction. The component may include one or more arches between the two ends.

[0023] In the deformed state, the component is adapted to limit the movement of the barrel in the longitudinal direction. This means that the movement of the barrel is not blocked or prevented in any case, but the movement of the barrel is only possible in a restricted manner. For example, the insertion force required for the movement of the barrel in the proximal direction is higher than in the non-deformed state.

[0024] The term "non-deformed state" means that, after manufacture, the component is in its initial state. The arch or any other part of the component has not been deformed by the user or by the assembly process (in particular, by inserting the cartridge into the housing). The distal end of the component does not move from its initial position.

[0025] In contrast, the term "deformed state" means that at least a section of the component, in particular the shape of the arch, has been changed from an initial shape to a new shape. In the deformed state, the distal end of the component moves relative to the housing away from the initial position of the component, for example, from a distal position to a proximal position. The term "deformed state" is not limited to a specific deformation of the arch, but the deformed state includes all positions and orientations of the component and in particular the arch that are different from their initial position, but in the deformed state, the arch deforms both elastically and plastically. In order to meet this restriction, the deformation of the material of the component must be in the so-called strain hardening region of the stress-strain curve of the material. This means that as soon as the deformation of the material exceeds the purely (linear) elastic region, the component is in a deformed state and irreversible plastic deformation occurs.

[0026] In the present context, the terms "substance", "drug", "medicament" and "drug" will be understood to include any flowable medical preparation suitable for controlled administration through a member such as, for example, a cannula or a hollow needle, and include liquids, solutions, gels or fine suspensions containing one or more medically active ingredients. A medicament may be a composition comprising a single active ingredient or a premixed or co-formulated composition having more than one active ingredient present in a single container. Drugs include drugs such as peptides (e.g., insulin, drugs containing insulin, drugs containing GLP-1 or derived products or similar products), proteins and hormones, active ingredients derived from or harvested from biological sources, hormone- or gene-based active ingredients, nutritional preparations, enzymes and other substances in both solid (suspended) or liquid form, and also polysaccharides, vaccines, DNA, RNA, oligonucleotides, antibodies or antibody parts, and also suitable alkaline substances, auxiliary substances and carrier substances.

[0027] The term "distal" is intended to refer to the direction or end of the drug delivery device carrying the injection needle or injection cannula, whereas the term "proximal" is intended to refer to the opposite direction or end pointing away from the needle or cannula.

[0028] The term "injection system" or "syringe" refers to a device that is removed from the injection site after each medication event or drug delivery process, while the term "infusion system" refers to a device with a cannula or needle that remains in the patient's skin for a long period of time (e.g., several hours).

[0029] In a preferred embodiment, the component is arm-shaped, and the arch of the component is located between the proximal end and the distal end of the arm-shaped component. The term "arm-shaped" means that the component preferably has a longitudinal shape or is formed between the proximal end and the distal end of the component. Therefore, the length is greater than the width of the component. However, the arm-shaped component does not have to extend along the longitudinal direction of the housing, but the arm-shaped component can extend along any other direction, or the entire component can have a curved form that is not extended along a specific direction. The arm-shaped component realizes the favorable force shifting of the force acting on the barrel when the barrel is inserted into the housing. In addition, the arm-shaped allows the efficient production of components. When the component is made of plastic, the arm-shaped is easy to demould from the injection molding tool.

[0030] Preferably, the component is deformable in the region of the arch.However, during the deformation from the non-deformed state to the deformed state, other parts of the component may also be deformed.

[0031] Preferably, the component can be deformed from a non-deformed state to a deformed state by displacement of the distal end of the component relative to the housing in the longitudinal direction (particularly, by proximal displacement). The displacement is preferably caused when the tube is inserted into a recessed portion of the housing with its proximal portion and moves in a proximal direction parallel to the longitudinal axis. This means that during the insertion of the tube in the longitudinal direction, the distal end of the component also moves substantially in the longitudinal direction. This allows easy and rapid deformation of the component, and thus allows easy and rapid restriction of the movement of the tube relative to the housing.

[0032] Alternatively, the component may be deformable from the non-deformed state to the deformed state by moving the distal end in a direction perpendicular to the longitudinal direction or in any other direction.

[0033] In a preferred embodiment, the distance between the proximal end and the distal end of the parts defines the length of the parts in the longitudinal direction, wherein, in the deformed state, the length is reduced compared to the non-deformed state. Preferably, the parts and particularly the arched portion are bent or deformed so that the length of the parts is reduced during deformation. Due to the deformation, at least part of the arched portion is squeezed and / or stretched. The strain of the material caused by the deformation causes a force that acts at least partially in the longitudinal direction, and is thus suitable for biasing the inserted tube against the tube holder or any corresponding element at the distal end of the tube in the assembled state.

[0034] Alternatively, in the deformed state, the length of the component increases compared to the non-deformed state. This may occur, for example, if an arcuate portion of the component stretches during deformation.

[0035] Preferably, in the deformed state, the first portion of the arch is elongated and the second portion of the arch is compressed compared to the non-deformed state. Thus, the arch is deformed in such a way that the initial curve of the arch is further bent. For example, in the deformed state, the inner radius defining the inner curvature of the arch may be reduced compared to the non-deformed shape. Such a deformation allows a space-saving design of the component. Furthermore, such a deformation allows a continuous and well-predictable force progression in relation to the deformation path.

[0036] Alternatively, the arch may deform in any other manner, such as deformation by elongation only or by compression only.

[0037] In a preferred embodiment, the component includes a second arch between the proximal end and the distal end, and wherein the first arch and the second arch described above constitute an S-shaped form in a non-deformed state and a deformed state. The term "S-shaped" means that the component has an S-form more or less. This means that the first arch is preferably arranged adjacent to the second arch along a continuous line of the form of the component. The two arches of the component do not have to form an S curve accurately and completely. The S-shaped form further allows a compact design. In an S-shaped component, the strains and stresses in the body of the component are advantageously and widely dispersed in the body of the component, and local strain peaks and local stress peaks can thus be reliably avoided. In addition, during deformation, the S-shaped form of the component allows a continuous and optimal force progression related to the deflection of the component.

[0038] The second arched portion allows the design of the deformable component so that the resistance or holding force of the deformable component during its deformation is smooth, continuous and can be maintained within an optimal range. That is, the force associated with the deflection (deformation path) of the s-shaped component is strongly increasing in the first section and is very low or almost constant in the second section. The almost constant section is desirable because a barrel with the smallest length of the tolerance range and a barrel with the largest length of the tolerance range can be held with almost the same predetermined force.

[0039] Preferably, the component is deformable in the first arch and the second arch, in particular only in the first arch and the second arch. Parts of the component that do not belong to the first arch or the second arch are thus preferably not deformed. Thus, during the deformation from the non-deformed state to the deformed state, only the first arch and the second arch are deformed, and the remaining part of the component is not deformed.

[0040] In alternative embodiments, the component may be designed such that in the deformed state of the component, only one of the two or more arches is deformed, and the other arches are not deformed.

[0041] Preferably, the plan area of ​​the cross section of the component varies between the proximal end and the distal end. The plan area of ​​the cross section lies in a plane perpendicular to the centerline of the component. In a preferred embodiment, the component tapers, or the component comprises at least a tapered portion. The varying plan area of ​​the cross section allows the position of the deformable arched portion to be optimally defined. Thus, the plan area in the deformable portion of the arch can be reduced compared to the non-deformable portion of the component, so that the position of the deformation is precisely defined and predictable. Furthermore, the plan area in the deformable portion can be designed so that the portion can be easily and optimally deformed.

[0042] In a preferred embodiment, the component is formed integrally with the housing. Thus, the component is formed as a single piece and is preferably formed from the same material as the housing. This allows efficient production of housings with deformable components.

[0043] Alternatively, the deformable component may be a separate and unitary part connected, for example by adhesive bonding or by a snap-fit ​​connection.

[0044] Advantageously, the component is made of a polymer such as polyoxymethylene, polypropylene, polyethylene, polycarbonate-acrylonitrile-butadiene-styrene, polybutylene terephthalate, polyester or polyamide. These polymers, in particular polyethylene, can be easily deformed and have advantageous elongation values ​​at break. This means that the deformable component can be deformed both plastically and elastically within a certain deformation range without the risk of breakage. The material polypropylene is very ductile, which means that the deformable component is easy to stretch or easy to deform.

[0045] In a preferred embodiment, the housing comprises at least two deformable components as described above arranged inside the recess. The two or more components are preferably arranged circumferentially and preferably spaced evenly and / or symmetrically from each other. Thus, the movement of the cartridge inserted into the recess of the housing can be limited by at least two components and preferably a plurality of components, and thus the movement is limited in a safe and optimal manner.

[0046] Preferably, the proximal end of the component is attached to a connection surface of the housing located inside the recess and extends substantially in the longitudinal direction and preferably in the distal direction. This means that the component extends from a surface perpendicular to the insertion direction of the barrel (which is in the longitudinal direction). The term "substantially" means that the connection surface may not be oriented exactly in the longitudinal direction, but may be oriented to about -10° to +10° different from the longitudinal direction.

[0047] The proximal end is preferably attached to a connection surface on the side wall and is thus not in the space filled by the inserted cartridge. If the cartridge is inserted deeper into the recess than the final axial end position, the deformable member is deflected and the arch deforms further, but movement of the cartridge is not blocked by the deformable member.

[0048] Preferably, if the cartridge moves further into the housing, the cartridge abuts against an axial end stop element inside the housing, which separates from the deformable component. Since the deformable component is attached to a surface extending in the longitudinal direction or to the side wall of the recess, the resistance of the component can only increase to a certain maximum value. Therefore, the cartridge cannot be damaged or destroyed by the component, because the force acting on the cartridge cannot exceed a maximum value or a predefined threshold value.

[0049] In contrast, any deformable element or spring attached to a connection surface perpendicular to the longitudinal direction (and therefore perpendicular to the movement of the insertion tube) or a deformable element arranged on the proximal front end side of the inserted tube can only be deformed to a certain maximum value and, when the tube is inserted too deeply into the recess, the resistance caused by the component can suddenly increase to a breaking force.

[0050] In a preferred embodiment, the connection surface is an outer wall of the element inside the recess of the housing.

[0051] Such an outer wall may for example be an outer surface of an insert element coaxially arranged inside the recess, wherein the outer wall of the insert extends along the longitudinal direction. In this case, the component preferably extends radially outwards from the outer wall in the direction of the inner side wall of the recess.

[0052] In an alternative embodiment, the connecting surface is the inner side wall of the recess. In this case, the component preferably extends radially inwards from the inner side wall to the center of the recess.

[0053] The housing preferably comprises a stop element adapted to prevent the barrel from moving beyond the stop element in the distal longitudinal direction. The stop element is separate from the deformable component. This means that the stop element is not a component or part of the deformable component. The stop element may be formed integrally with the housing, or the stop element may be a separate element connectable to the housing.

[0054] The stop element is adapted to block or prevent any movement of the barrel in the proximal and longitudinal direction. In contrast, the deformable component is adapted to limit the movement of the barrel in the proximal and longitudinal direction, which means that the movement itself is not prevented, but the movement is restricted and the movement depends on the force acting on the barrel in the longitudinal direction.

[0055] Since the stop element is separated from the deformable component, the two functions of limiting movement (and / or biasing the barrel) and providing an axial end stop are separated. This allows for an optimal design of each function. This means that the deformable component can be designed so that the resistance or retention force associated with the deflection of the deformable component (caused by the deformed component) can be optimally adjusted to a specific barrel length or length range. In addition, a stop end adapted to prevent the barrel from moving proximally beyond a specific axial position inside the housing can be provided independently of the deformable component in a space-saving design.

[0056] The present invention further relates to a barrel unit, which comprises: a housing as described above; a barrel containing a liquid drug; a barrel holder for accommodating a distal portion of the barrel and connectable to the distal end of the housing so that the barrel is held relative to the housing by the barrel holder and the housing. The component is preferably deformable from a non-deformed state to a deformed state by displacement of the distal end of the component. The displacement is preferably caused by inserting the proximal portion of the barrel into the housing, wherein the proximal end of the barrel abuts the distal end of the component. Therefore, in the deformed state, the proximal end of the barrel abuts the distal end of the component.

[0057] In a preferred embodiment, and, under assembled state, the distal portion of tube is located in the tube holder, and the proximal portion of tube is located in the housing. In addition, the proximal end of the tube holder is connected to the distal end of the housing. Thereby, tube is retained in the tube holder and the housing, because, parts are in a deformed state, and the deformed parts limit tube relative to the movement of housing and tube holder.

[0058] Furthermore, the present invention relates to a drug delivery device for administering a liquid drug from a cartridge, the drug delivery device comprising a cartridge unit and a dosing and dispensing mechanism as described above.

[0059] The invention further relates to a method for assembling a cartridge unit for a drug delivery device, the method comprising the steps of:

[0060] a. providing a housing including a recessed portion for accommodating a proximal portion of the barrel, the recessed portion having an axis defining a longitudinal direction, a deformable member disposed inside the recessed portion, wherein the deformable member includes a proximal end attached to the housing and a distal end movable relative to the housing within the recessed portion, the member further comprising an arched portion;

[0061] b. inserting the distal portion of the cartridge into the opening of the sleeve-shaped cartridge holder;

[0062] c. The proximal portion of the cartridge holder having a cartridge is inserted into the recessed portion of the housing in the longitudinal direction;

[0063] d. deforming the deformable member of the housing from a non-deformed state to a deformed state by displacement of the distal end of the member in a proximal and longitudinal direction through the proximal end of the barrel, and thereby deforming the arched portion both elastically and plastically;

[0064] e. Connecting the proximal portion of the cartridge holder to the distal portion of the housing, in particular by means of a snap lock.

[0065] The barrel can first be inserted into the opening of the barrel holder with its distal part, and, secondly, the barrel holder with the inserted barrel can be connected to the housing with the proximal end of the barrel holder. Alternatively, the barrel can first be inserted into the opening of the housing with its proximal part, and, secondly, the barrel holder can be pulled on the distal part of the barrel, and, thirdly, the proximal end of the barrel holder can be connected to the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The subject matter of the invention will be explained in more detail in the following text with reference to preferred exemplary embodiments illustrated in the accompanying drawings, in which:

[0067] Figure 1 A perspective view depicting an injection pen;

[0068] Figure 2a depicting a cross-sectional side view, wherein the cut extends along a longitudinal axis of the housing;

[0069] Figure 2b depicts a front view of the housing without the cartridge and cartridge holder;

[0070] Figure 3a-3d Describe the deformation of the component from a non-deformed state to a deformed state;

[0071] Figure 4 depicting a graph showing the progression of forces associated with deflection of a component;

[0072] Figure 5 Depicts a cross-sectional side view of a housing for a smaller cartridge.

[0073] The reference symbols used in the drawings and their essential meanings are listed in summary form in the list of names. In principle, identical parts are provided with the same reference symbols in the drawings. DETAILED DESCRIPTION

[0074] In the following a drug delivery device having a cartridge unit and a housing according to the invention is described.In the described embodiment the drug delivery device is an injection pen. Figure 1 Some parts of the injection pen are shown in perspective, namely the housing 40, the barrel 30, the barrel holder 20 and the pen cap 10. The injection pen further comprises a dosing and dispensing mechanism which is not further described here. The housing 40, the barrel 30 and the barrel holder 20 form a barrel unit. In the following, the barrel unit is described in detail. First, the structural features are described and secondly, the functional features are described in detail.

[0075] Figure 2aA cross-sectional view of a cartridge unit is depicted, wherein the section of the cross-sectional view extends along the longitudinal axis of the housing 40. The housing 40 has a sleeve form and is made of polypropylene. In the proximal portion of the housing 40, the dosing and dispensing mechanism is accommodated. The housing 40 comprises a recess 48 at the distal end portion, which is adapted to accommodate the proximal portion of the cartridge 30. The recess 48 has a substantially cylindrical shape. The opening forms the distal end of the recess 48, while the recess is provided by four pillars 49 (see FIG. 1 ) which are circumferentially spaced apart from each other. Figure 2b ) forms the proximal end of the recess 48. A support 49 supports an insert 45 which has a through hole in the center of the recess. The latter serves as a guide for an axially movable piston rod (not shown) of a dosing and dispensing mechanism (not shown). The axis from the distal end to the proximal end of the recess 48 defines the longitudinal direction.

[0076] If available Figure 2a and Figure 2b As can be seen in FIG. 1 , two deformable parts in the form of arms 41.1 and 41.2 are attached to the peripheral wall of the insert 45. The two arms 41.1 and 41.2 are circumferentially spaced apart from each other. The distal end 52 of each arm 41.1 and 41.2 is movable relative to the housing 40 in the recess 48, and the proximal end of each arm 41.1 and 41.2 is inseparably attached to the outer wall of the insert 45. Each arm 41.1 and 41.2 comprises a first arch 42 and a second arch 43 arranged so that the arm has an S-shape (see FIG. 1 ). Figure 3a-3d ). Starting from the proximal end of the attachment of the arm, the arm 41.1, 41.2 has a bend or curvature in the proximal direction from the wall of the insert 45 by means of a first arch 42. The second arch 43 is adjacent to the first arch, and the arm 41.1, 41.2 thus has a bend or curvature in the distal direction backwards by means of the second arch 43. Each arm 41.1, 41.2 further comprises a straight section 44 at the distal part of the arm 41.1, 41.2. The straight section 44 extends substantially in the longitudinal direction. The straight section 44 comprises ribs (not shown) on its outer side so that the cross section of the straight section is not rectangular. The distal end 52 of the arm can move relative to the inner side wall of the recess 48.

[0077] The plan area of ​​the cross section of each arm 41.1, 41.2 varies between the distal end and the proximal end of the arm. That is, the plan area of ​​the cross section decreases from the distal end of the arm 41.1, 41.2 to the arched portion 42, 43 of the arm, so that the plan area of ​​the cross section in the s-shaped portion is reduced compared to the plan area of ​​the cross section in the distal portion of the arm 41.1, 41.2.

[0078] On the inner side wall of the recess 48 there are two sliding surfaces 47 arranged in the longitudinal direction and circumferentially spaced from each other such that the sliding surfaces 47 are immediately adjacent to the distal end 52 of each arm 41 . 1 , 41 . 2 .

[0079] The housing further comprises an end stop 53 which blocks or prevents the cartridge from moving proximally beyond the end stop position. The end stop 53 comprises a stop surface which is arranged perpendicular to the insertion direction and which is arranged on each strut 49 at the bottom of the recess. When the cartridge moves proximally beyond its final axial position, the cartridge abuts the end stop 53 after a short movement in the proximal direction. Thus, the end stop 53 prevents further insertion in the proximal direction.

[0080] like Figure 1 4. The tube holder 20 shown in the embodiment is also sleeve-shaped, and comprises the recessed part that is suitable for accommodating the distal part of tube 30.The tube holder 20 comprises a latch or a hook 21 at its proximal end, and latch or a hook 21 are suitable for engaging with the aperture 51 or corresponding elements arranged on the distal end of housing 40. In the embodiment shown, the tube holder 20 can be connected to the distal end of housing by a spring lock connection with its proximal end. Alternatively, the tube holder 20 can be connected with housing 40 by any other connecting means (for example, by adhesion bonding, by plastic welding, by screw thread or by bayonet fitting).

[0081] Reference below Figures 3a to 3d The function of the deformable arms 41 . 1 , 41 . 2 and the interaction of the cartridge 30 with the housing and cartridge holder 20 are described below.

[0082] Figures 3a to 3d A detailed and cross-sectional view of the deformable arms 41.1, 41.2 of the housing 40 is shown. The cut of the cross-sectional view extends along the longitudinal direction of the housing 40 and only the upper part of the cross section is shown. Figure 3a , the initial and non-deformed state of the deformable arms 41.1, 41.2 is depicted. When the cartridge 30 is inserted with its proximal portion into the recess 48, the proximal end or rim portion 31 of the cartridge 30 abuts against the distal ends 52 of the arms 41.1, 41.2. If the cartridge 30 is inserted further proximally and into the recess 48 of the housing 40 in the longitudinal direction, the rim portion 31 of the cartridge 30 moves the distal ends 52 of the arms 41.1, 41.2 radially outward on the sliding surface 47 and slightly moves the distal ends 52 in the proximal direction, as shown in FIG. Figure 3b4. As shown in FIG. 4, the outer distal edge of the arm abuts the sliding surface 47 on the inner side wall of the recess 48, and the distal end 52 of each arm 41.1, 41.2 moves further in the proximal direction, sliding along the surface 47. This movement deforms the two arched portions 42, 43 of each arm 41.1, 41.2. Since the polypropylene material of the arms 41.1, 41.2 is elastically deformed at this stage, a reaction force or resistance is caused by this deformation. This reaction force or resistance acts on the edge portion 31 of the barrel 30 and is directed substantially in the distal direction.

[0083] The further insertion of the barrel 30 in the proximal direction causes the distal ends 52 of the arms 41.1, 41.2 to move further in the proximal direction along the sliding surface 47 of the side wall of the recess 48, and thereby further deforms the arches 42, 43 of each arm 41.1, 41.2. In particular, the first arch 42 is bent towards the center line or center of the recess 48. Due to this movement, at least one of the two arches 42, 43 is plastically deformed. This means that the deformation is irreversible and, even after the force applied due to the insertion of the barrel is removed, the deformation is maintained. From this moment on, the arms 41.1, 41.2 are in a deformed state. This means that in the deformed state, the deformation of the material exceeds a purely linear elastic deformation.

[0084] exist Figure 3c 4 shows the position of the arms 41.1, 41.2 after further insertion of the barrel 30 in the proximal direction. At this stage, the first arch 42 and the second arch 43 are significantly deformed. The first arch 42 is bent or pressed toward the rigid outer wall of the insert 45, while the second arch 43 is widened or stretched.

[0085] Figure 3d The final insertion position of the cartridge 30 is shown. The first arched portion 42 and the second arched portion 43 of the arms 41.1 and 41.2 are larger than in FIG. Figure 3a to Figure 3c 1, 41.2 is deformed even more in the previous position shown in FIG. The deformation of the arms 41.1, 41.2 still occurs elastically and plastically and the arms 41.1, 41.2 are still in a deformed state. In the event that the cartridge 30 is inserted further into the recess in the longitudinal direction, the reaction force will only increase slightly to a maximum value. However, due to the S-shape of the arms 41.1, 41.2, the reaction force cannot exceed the maximum value. Figure 4 This effect is described in detail with reference to the force-deflection diagram of FIG. 1. In this final position, the edge portion 31 is close to the end stop 53, but does not yet abut the end stop 53.

[0086] After the cartridge 30 is inserted into the recess 48 of the housing 40 up to a predefined axial position (insertion end position), the cartridge holder 20 is snapped with its latch or hook 21 at the proximal end together with the aperture 51 at the distal end of the housing 40. The cartridge 30 may first be inserted with its distal portion into the recess of the cartridge holder, and then the cartridge holder 20 with the cartridge 30 may be connected to the housing 40, or the cartridge 30 may first be inserted with its proximal portion into the recess 48 of the housing 40, and then the cartridge holder 20 may be placed over the distal end of the cartridge 30 and subsequently connected to the housing 40.

[0087] exist Figure 4 In FIG. 4 , a force-deflection diagram is depicted, which shows the force progression (force versus deflection) of the reaction force (resistance) of the arms 41 . 1 , 41 . 2 in relation to the deflection or deformation path of the arms.

[0088] The horizontal axis (named s-axis) shows the deflection amount or deformation path of the arms 41.1, 41.2 in the proximal and longitudinal direction when the distal ends 52 of the arms 41.1, 41.2 are displaced from the initial distal position to the proximal position in the deformed state. The vertical axis (named f-axis) shows the force progression of the reaction force or resistance of the arms 41.1, 41.2.

[0089] The first section 61 of the curve in the figure is almost linear. This is the deformation when the arm is bent radially outward (corresponding to Figure 3b 1 , 41.2) and the material of the arms 41.1, 41.2 is then in its linear elastic region. A further deflection of the arms (only an axial movement of the distal ends 52 of the arms 41.1, 41.2 in the proximal direction is possible) suddenly increases the force. The curve in the figure has a sharp bend and then rises strongly in a non-linear second section 62. From this point of view, the behavior is non-linear and, at this stage, not only elastic deformation of the arms 41.1, 41.2 occurs, but also plastic deformation of the arms 41.1, 41.2. Thus, the arms 41.1, 41.2 have been transformed from a non-deformed state into a deformed state. This means that at this stage, the material is not only deformed elastically, but also plastically.

[0090] Due to the arched arms, the force-deflection curve has a predefined optimal course. That is, the maximum value of the force is chosen so that the cartridge is not damaged. Even if the cartridge is longer than expected, or even if the cartridge is inserted too deeply into the housing, the resistance or reaction force acting on the cartridge does not exceed the predefined maximum value. This means that the force-deflection curve flattens or is almost horizontal at greater deflections of the arms (see the left end section of the figure).

[0091] The uninterrupted line or the solid line of this curve diagram show the contrast of behavior deflection and force in the new molded polypropylene material.The dotted line of this curve diagram is presented in the behavior under the situation of storing polypropylene material 100000 hours.Due to the reason of material relaxation, the situation of resistance is lower than new material.Yet, under the situation of S-shaped arm according to the present invention, resistance is still higher than making tube against tube holder bias so that tube is reliably maintained in tube holder and housing required minimum force.

[0092] Vertical lines 63, 64 and 65 define the deflection range for keeping tube. This range is wider, so as to cover tubes with different lengths. Left vertical line 63 defines the lower end of the range when keeping short tube or has the lower threshold value of minimum deflection. The force generated by the deformed arm is still high enough to make the short tube against the tube holder bias to reliably and safely keep the tube in the tube holder and the housing. The vertical line 64 in the middle of the deflection axis marks the nominal value 64 of the deflection. Right vertical line 65 defines the upper end of the deflection for a longer tube. If a long tube is inserted, the force generated by the deformed arm does not exceed the value of pre-defined, and, even the long tube cannot be damaged.

[0093] Figure 5 Describes a cross-sectional view of another embodiment of the present invention. Figure 1 3 to describe the larger cartridge housing 40 (eg, for a cartridge containing 3 ml of drug), Figure 5 The housing 140 shown in FIG. 1 is suitable for cartridges having a smaller diameter, for example for cartridges containing 1.5 ml of drug.

[0094] and Figure 1 In contrast to the above-described embodiment of FIG. 3 , the arm 141 is attached to the inner wall of the recess, rather than to the insert of the housing 140. In addition, the arm 141 comprises only one arch 142. The proximal end of the arm is attached to the inner wall of the recess, and the first proximal section 146 of the arm 141 extends obliquely in the proximal direction. The arch 142 follows the proximal section 146, so that the distal and straight section 144 of the arm 141 points in the distal direction. In the straight section 144, the arm 141 comprises a ledge 143 directed radially inwards, which is suitable for supporting the edge portion 31 of the inserted barrel.

[0095] The cartridge is inserted into the housing 140 and the deformation of the arms 144 corresponds to the deformation described above with reference to Figure 1 3 . That is, when the barrel is inserted, the proximal end or edge portion of the barrel abuts the lug 143. Further insertion of the barrel moves the distal end of the arm 144 in the proximal direction. This causes deformation of the arch 142, and the arm 144 is deformed from a non-deformed state to a deformed state, as described above with respect to the first embodiment.

[0096] Although the present invention has been described in detail in the drawings and the foregoing description, such description will be considered illustrative or exemplary rather than restrictive. Personnel skilled in the art and practicing the claimed invention can understand and realize variations to the disclosed embodiments by studying the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude multiple. The mere fact that certain elements or steps are described in distinct claims does not indicate that the combination of these elements or steps cannot be used for profit, and specifically, any other meaningful claim combination should be considered to be disclosed except for the actual claim dependencies.

[0097] Name List

[0098] 10 Cap

[0099] 20 Cartridge holder

[0100] 21 Latch element

[0101] 30 tubes

[0102] 31 Edge

[0103] 40 Shell

[0104] 41.1, 41.2 Arm

[0105] 42 first arch

[0106] 43 Second arch

[0107] 44 straight section

[0108] 45 Insert

[0109] 46 Outer wall of insert

[0110] 47 Sliding surface

[0111] 48 Depression

[0112] 49 Pillar

[0113] 51 Pore

[0114] 52 Remote

[0115] 53 End stop

[0116] 61 Linear segments

[0117] 62 Nonlinear sections

[0118] 63 left vertical line

[0119] 64 Nominal value line

[0120] 65 right vertical line

[0121] 140 Shell

[0122] 141.1, 141.2 Arm

[0123] 142 Arch

[0124] 143 Lug

[0125] 144 Straight section

[0126] 146 proximal segment.

Claims

1. A housing for a drug delivery device for administering a liquid drug from a cartridge, the delivery device comprising a housing, the cartridge and a cartridge holder adapted to hold the cartridge relative to the housing inside the drug delivery device, wherein: The housing comprises: a recessed portion for receiving a proximal portion of the barrel, the recessed portion having an axis defining a longitudinal direction; a deformable component arranged inside the recessed portion, The deformable member includes a proximal end attached to the housing and a distal end movable relative to the housing within the recess, wherein the deformable member is deformable from a non-deformed state to a deformed state by displacement of the distal end, wherein in the deformed state the proximal end of the barrel abuts the distal end of the deformable member, and wherein in the deformed state the deformable member is further adapted to limit movement of the barrel present in the recess relative to the housing in the longitudinal direction, It is characterized in that The deformable component comprises an arched portion, and in the deformed state, the arched portion deforms both elastically and plastically; the deformable component is arm-shaped, and wherein the arched portion is located between the proximal end and the distal end of the arm-shaped deformable component.

2. The housing according to claim 1, characterized in that The deformable member is deformable from the non-deformed state to the deformed state by displacement of the distal end relative to the housing in the longitudinal direction.

3. The housing according to claim 1 or 2, characterized in that: A distance between the proximal end and the distal end defines a length of the deformable member along the longitudinal direction, wherein in the deformed state, the length is reduced compared to the non-deformed state.

4. The housing according to claim 1 or 2, characterized in that: In the deformed state, a first portion of the arched portion is elongated and a second portion of the arched portion is compressed compared to the non-deformed state.

5. The housing according to claim 1 or 2, characterized in that: The deformable component comprises a first arched portion and a second arched portion, wherein the first arched portion and the second arched portion form an S-shaped form in the non-deformed state and the deformed state.

6. The housing according to claim 1 or 2, characterized in that: The planar area of ​​the cross-section of the deformable member varies between the proximal end and the distal end.

7. The housing according to claim 1 or 2, characterized in that: The deformable member is formed integrally with the housing.

8. The housing according to claim 1 or 2, characterized in that: The deformable member is made of a polymer selected from polyoxymethylene, polypropylene, polyethylene, polycarbonate-acrylonitrile-butadiene-styrene, polyester or polyamide.

9. The housing according to claim 1 or 2, characterized in that: At least two deformable components are arranged inside the recessed portion.

10. The housing according to claim 1 or 2, characterized in that: The proximal end of the deformable member is attached to the surface of the housing inside the recess and extends substantially along the longitudinal direction.

11. The housing according to claim 10, characterized in that The surface is an outer wall of an element inside the recess of the housing.

12. The housing according to claim 10, characterized in that The housing comprises a stop element adapted to prevent movement of the cartridge in a proximal direction beyond the stop element, wherein the stop element is decoupled from the deformable component.

13. The housing according to claim 8, characterized in that The deformable member is made of polybutylene terephthalate.

14. A cartridge unit for a drug delivery device, the cartridge unit comprising: A housing according to any one of claims 1 to 13; a cartridge containing the liquid medication; a cartridge holder for receiving a distal portion of the cartridge and connectable to a distal end of the housing such that the cartridge is held relative to the housing by the cartridge holder and the housing; Wherein, in the deformed state, the proximal end of the barrel abuts the distal end of the deformable component.

15. A drug delivery device for administering a liquid drug from a cartridge, comprising a dosing and dispensing mechanism and a cartridge unit according to claim 14.

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