WO2013139894A1

WO2013139894A1 - Housing of a drug delivery device

Info

Publication number: WO2013139894A1
Application number: PCT/EP2013/055905
Authority: WO
Inventors: Michael Jugl
Original assignee: Sanofi-Aventis Deutschland Gmbh
Priority date: 2012-03-22
Filing date: 2013-03-21
Publication date: 2013-09-26

Abstract

The present invention relates to a housing of a drug delivery device and to a respective drug delivery device to administer a predefined amount of a medicament, the housing comprising : - a body (14) to accommodate a drive mechanism (11) having a piston rod (30) to operably engage with a piston of a cartridge (32) containing the medicament, a cartridge holder (16) to accommodate the cartridge (32), the cartridge holder (16) connectable with a distal end of the body (14), a protective cap (12) to cover the cartridge holder (16) and being directly releasably interconnectable with the body (14).

Description

Housing of a Drug Delivery Device

Description The present invention relates to a housing of a drug delivery device such as a pen- type injector.

Background and Prior Art Drug delivery devices for setting and dispensing a single or multiple doses of a liquid medicament are as such well-known in the art. Generally, such devices have substantially a similar purpose as that of an ordinary syringe.

Drug delivery devices, in particular pen-type injectors have to meet a number of user-specific requirements. For instance, with patient's suffering chronic diseases, such like diabetes, the patient may be physically infirm and may also have impaired vision. Suitable drug delivery devices especially intended for home medication therefore need to be robust in construction and should be easy to use.

Furthermore, manipulation and general handling of the device and its components should be intelligible and easy understandable. Moreover, a dose setting as well as a dose dispensing procedure must be easy to operate and has to be unambiguous.

Typically, such devices comprise a housing adapted to receive a cartridge at least partially filled with the medicament to be dispensed. The device further comprises a drive mechanism, typically having a displaceable piston rod which is adapted to operably engage with a piston of the cartridge. By means of the drive mechanism and its piston rod, the piston of the cartridge can be displaced in a distal or dispensing direction and may therefore expel a predefined amount of the

medicament via a piercing assembly which is to be releasably coupled with a distal end section of the housing of the drug delivery device.

Typically, such drug delivery devices of e.g. pen-injector type comprise a housing or body to accommodate a drive mechanism and further comprise a cartridge holder adapted to accommodate a cartridge filled with the medicament. Especially with disposable devices, cartridge holder and body are inseparably interconnected . They may be adhesively bonded or mutually welded . The cartridge holder at its distal end comprises a threaded socket to removably receive a correspondingly threaded needle assembly by way of which the medicament provided in the cartridge can be dispensed . When not in use, the needle assembly is to be disconnected from the cartridge holder. For protecting the cartridge holder and the cartridge arranged therein against environmental influences, a removable protective cap is to be mounted on the cartridge holder.

Typically the cap releasably engages with the cartridge holder by means of one or several snap members provided on the outer circumference of the tubular shaped cartridge holder. When mounted on the cartridge holder, there may form a circumferential gap or groove between a proximal end of the protective cap and a distal end of the body, which may further vary in size depending on geometric tolerances of the various housing components of the device and their mutual assembly. A rather large groove or gap between the protective cap and the body of the pen-type injector is considered disadvantageous in regard of the quality of the drug delivery device and its outer surface.

Objects of the invention

It is therefore an object of the present invention to provide an improved housing of a drug del ivery device, in particular of a pen-type injector featuring an almost seamless outer appearance, in particular in the interface region of protective cap and body. Moreover, the invention also aims to provide a high-quality outer surface of the drug del ivery device even when housing components and their mutual assembly are subject to geometric tolerances. Summary of the invention The present invention provides a housing of a drug delivery device adapted to administer a predefined amount of a medicament. In particular, the housing comprises at least three housing components of a drug delivery device of pen- injector type. The housing at least comprises a body, preferably of substantially tubular shape and being adapted to accommodate a drive mechanism of the drug delivery device. The drive mechanism at least comprises a piston rod to operably engage with a piston of a cartridge containing the medicament to be administered or to be dispensed by the device. Moreover, the housing also comprises a cartridge holder being adapted to accommodate the cartridge. With a proximal end section the cartridge holder is connectable with a distal end of the body. When provided as a disposable drug delivery device, the cartridge holder is preferably inseparably connected with the body. However, with reusable drug delivery devices, the cartridge holder and the body may be releasably interconnected in order to replace an empty cartridge.

Additionally, the housing comprises a protective cap to cover the cartridge holder, especially when the device is not in use. It is of particular benefit, that the protective cap is directly and releasably interconnectable with the body while covering the cartridge holder. This way, varying geometric properties within given tolerance margins of the cartridge holder and its assembly with the body do no longer have an influence on the size of a gap or groove between the body and the protective cap when mounted on the cartridge holder. Generally, an in order to eliminate or to compensate axial tolerances between a piston of a cartridge and the piston rod of the drive mechanism of the device, relative axial positions of the cartridge holder and the body may slightly vary. By directly connecting the protective cap with the body, the outer appearance of the drug delivery device is no longer influenced by such geometric tolerances and the gap size between protective cap and body may be kept minimal. In fact, the outer appearance of the housing of the drug delivery device can be improved and eventual geometric tolerances of the components of the device and their mutual assembly do no longer reflect in the outer appearance of the drug delivery device.

In a preferred aspect, the protective cap and the body are positively engageable. It is of particular benefit, when the body comprises at least one resiliently deformable snap member to engage with a correspondingly shaped snap member of the protective cap. This way, the cap and the body can be releasably interconnected simply by pushing the protective cap in proximal direction towards the body until the mutually corresponding snap members engage. Removal of the protective cap from the body may just require to draw off the protective cap in distal direction, hence, away from the body. In a further preferred embodiment, the body and/or the cartridge holder comprise a tubular shape. Furthermore, the snap member of the body and/or the snap member of the protective cap is or are deformable in radial direction. It is of particular benefit, when the at least one snap member of the body extends radially outwardly and engages with the protective cap by a radially inwardly directed resilient deformation. Hence, when the protective cap is mounted on the cartridge holder, the mutually engaging snap members of protective cap and body are invisible from outside the device.

In a further preferred embodiment, the body comprises at least two snap members distributed along the tangential or outer circumference of the body and/or of the cartridge holder. As seen in tangential direction of the tubular shaped cartridge holder or body, the at least two snap members may be arranged on opposite lateral sides of the body. In order to provide a rather smooth and secure mutual fastening of protective cap and body, also a plurality of substantially evenly distributed snap members may be provided. It is of particular benefit and according to another preferred embodiment, when the protective cap comprises a radial and circumferentially extending recess or groove at an inside wall to mate or to engage with the at least one snap member of the body. The groove of the protective cap serves as the snap member of the cap and provides an orientation-invariant interconnection with the body. Hence, the protective cap can be interconnected with the body at an arbitrary orientation with respect to its long axis.

In still another embodiment, the body of the housing comprises a receptacle at its distal end to receive an insert portion of the cartridge holder. Consequently, body and cartridge holder are interconnectable in an interleaved or at least partially overlapping or nested manner. When provided as a reusable device, the insert portion of the cartridge holder and the receptacle of the body may comprise mutually corresponding threads in order to threadedly engage body and cartridge holder. When provided as a disposable device, the body and the cartridge holder may be inseparably interconnectable, either by way of a positive engagement or by way of mutually bonding or welding the receptacle and the insert portion.

In another embodiment, the at least one snap member of the body protrudes from a distal end of the receptacle of the body in distal direction. Hence, the at least one snap member at least partially extends into the cartridge holder in order to engage with the corresponding snap member of the protective cap.

Furthermore, and according to another embodiment, the cartridge holder and/or its insert portion comprises at least one recessed or stepped-down portion or a longitudinal slit, preferably at its proximal end to receive the at least one snap member of the body extending in distal direction. Instead of a slit, the cartridge holder and/or its insert portion may also comprise a radial recess in order to receive the snap member. Preferably, the at least one snap member of the body at least partially protrudes radially outwardly from the adjacently located outer surface of the cartridge holder and/or its insert portion. This way, the at least one snap member of the body may extend distally into the adjacently arranged cartridge holder and may radially and resiliently protrude from an outer surface of the cartridge holder. The snap member may then releasably and positively engage with the protective cap. Said cap may be shaped and designed to substantially flush with the outer side wall portion and hence with a distally located edge or stepped down portion of the body when fixed therewith.

By means of the axially extending and radially resiliently deformable snap member, the protective cap is fixable to the body of the housing in an axial abutment configuration and in a radially non-overlapping configuration with said body. It is only the at least one snap member which radially overlaps and engages with the protective cap in a region distally separated from a distal end of the body.

This way, the radially protruding snap member of the body can easily engage with a corresponding snap member of the protective cap. Moreover, when providing a radial recess in the cartridge holder and/or in its insert portion, also body and cartridge holder may be at least pre-assembled in a positively engaging manner, when the snap member of the body engages with the radial recess of a cartridge holder and/or of its insert portion. Hence, the snap member of the body may not only serve to provide as an interconnection means for the protective cap but may also at least preliminarily support the interconnection of body and cartridge holder.

In still another embodiment, the cartridge holder and the body are inseparably connected. This is of particular benefit, when the drug delivery device is designed as a disposable device, wherein the entire device is to be discarded when the content of the cartridge has been used up.

In a further preferred embodiment, the proximally located outer sidewall portion of the protective cap substantially flushes with an adjacently located distal outer sidewall portion of the body, when the protective cap is interconnected with the body. Here, it is beneficial, when the mutually corresponding snap members of the body and the protective cap are designed such, that the protective cap substantially seamlessly abuts with a distal end of the body when interconnected therewith. This way, the size of a potential gap or groove between the protective cap and the body can be reduced to a minimum, thereby providing a high-quality surface of the housing of the drug delivery device.

In another aspect, the invention also relates to a drug delivery device for

administering a dose of a medicament. The device, preferably of pen-injector type comprises a drive mechanism to operably engage with a piston of a cartridge. The drive mechanism typically at least comprises a piston rod to engage or to abut with a piston of such a cartridge. Furthermore, the drug delivery device comprises a housing as described above.

In a further preferred embodiment, the drug delivery device further comprises a cartridge arranged in the cartridge holder or its housing, wherein the cartridge is at least partially filled with the medicament to be dispensed by the drug delivery device.

Summary of the Invention The term "drug" or "medicament", as used herein, means a pharmaceutical formulation containing at least one pharmaceutically active compound, wherein in one embodiment the pharmaceutically active compound has a molecular weight up to 1500 Da and/or is a peptide, a proteine, a polysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody or a fragment thereof, a hormone or an oligonucleotide, or a mixture of the above-mentioned pharmaceutically active compound, wherein in a further embodiment the pharmaceutically active compound is useful for the treatment and/or prophylaxis of diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, thromboembolism disorders such as deep vein or pulmonary thromboembolism, acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and/or rheumatoid arthritis, wherein in a further embodiment the pharmaceutically active compound comprises at least one peptide for the treatment and/or prophylaxis of diabetes mellitus or

complications associated with diabetes mellitus such as diabetic retinopathy, wherein in a further embodiment the pharmaceutically active compound comprises at least one human insulin or a human insulin analogue or derivative, glucagon-like peptide (GLP-1 ) or an analogue or derivative thereof, or exendin-3 or exendin-4 or an analogue or derivative of exendin-3 or exendin-4.

Insulin analogues are for example Gly(A21 ), Arg(B31 ), Arg(B32) human insulin;

Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) human insulin; Asp(B28) human insulin; human insulin, wherein proline in position B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein in position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin. Insulin derivates are for example B29-N-myristoyl-des(B30) human insulin; B29-N- palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29 human insulin; B28-N-palmitoyl- LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N- palmitoyl- ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-Y-glutamyl)-des(B30) human insulin; B29-N-(N-lithocholyl-Y-glutamyl)-des(B30) human insulin; Β29-Ν-(ω- carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(uj-carboxyheptadecanoyl) human insulin.

Exendin-4 for example means Exendin-4(1 -39), a peptide of the sequence H-His-Gly- Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe- lle-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2. Exendin-4 derivatives are for example selected from the following list of compounds:

H-(Lys)4-des Pro36, des Pro37 Exendin-4(1 -39)-NH2,

H-(Lys)5-des Pro36, des Pro37 Exendin-4(1 -39)-NH2,

des Pro36 Exendin-4(1 -39),

des Pro36 [Asp28] Exendin-4(1 -39),

des Pro36 [lsoAsp28] Exendin-4(1 -39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1 -39),

des Pro36 [Met(O)14, lsoAsp28] Exendin-4(1 -39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1 -39),

des Pro36 [Trp(O2)25, lsoAsp28] Exendin-4(1 -39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1 -39),

des Pro36 [Met(O)14 Trp(O2)25, lsoAsp28] Exendin-4(1 -39); or des Pro36 [Asp28] Exendin-4(1 -39),

des Pro36 [lsoAsp28] Exendin-4(1 -39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1 -39),

des Pro36 [Met(O)14, lsoAsp28] Exendin-4(1 -39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1 -39),

des Pro36 [Trp(O2)25, lsoAsp28] Exendin-4(1 -39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1 -39),

des Pro36 [Met(O)14 Trp(O2)25, lsoAsp28] Exendin-4(1 -39),

wherein the group -Lys6-NH2 may be bound to the C-terminus of the Exendin-4 derivative; or an Exendin-4 derivative of the sequence

des Pro36 Exendin-4(1 -39)-Lys6-NH2 (AVE0010),

H-(Lys)6-des Pro36 [Asp28] Exendin-4(1 -39)-Lys6-NH2,

des Asp28 Pro36, Pro37, Pro38Exendin-4(1 -39)-NH2,

H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1 -39)-NH2,

H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1 -39)-NH2,

des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1 -39)-(Lys)6-NH2, H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1 -39)-(Lys)6-NH2, H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1 -39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1 -39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1 -39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1 -39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1 -39)-NH2, des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1 -39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1 -39)-(Lys)6-NH2, H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1 -39)-(Lys)6- NH2,

H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1 -39)-Lys6-NH2,

des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1 -39)-NH2,

H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1 -39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1 -39)-NH2, des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1 -39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1 -39)-(Lys)6-NH2, H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1 -39)-(Lys)6-NH2, H-Lys6-des Pro36 [Met(O)14, Trp(02)25, Asp28] Exendin-4(1 -39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25] Exendin-4(1 -39)-NH2, H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1 -39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1 -39)- NH2,

des Pro36, Pro37, Pro38 [Met(0)14, Trp(O2)25, Asp28] Exendin-4(1 -39)-(Lys)6-NH2, H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(S1 -39)- (Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1 -39)- (Lys)6-NH2; or a pharmaceutically acceptable salt or solvate of any one of the afore-mentioned Exendin-4 derivative. Hormones are for example hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists as listed in Rote Liste, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, Goserelin.

A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid, a heparin, a low molecular weight heparin or an ultra low molecular weight heparin or a derivative thereof, or a sulphated, e.g. a poly-sulphated form of the above-mentioned

polysaccharides, and/or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a poly-sulphated low molecular weight heparin is enoxaparin sodium.

Antibodies are globular plasma proteins (-150 kDa) that are also known as

immunoglobulins which share a basic structure. As they have sugar chains added to amino acid residues, they are glycoproteins. The basic functional unit of each antibody is an immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimeric with two Ig units as with IgA, tetrameric with four Ig units like teleost fish IgM, or pentameric with five Ig units, like mammalian IgM.

The Ig monomer is a "Y"-shaped molecule that consists of four polypeptide chains; two identical heavy chains and two identical light chains connected by disulfide bonds between cysteine residues. Each heavy chain is about 440 amino acids long; each light chain is about 220 amino acids long. Heavy and light chains each contain intrachain disulfide bonds which stabilize their folding. Each chain is composed of structural domains called Ig domains. These domains contain about 70-1 10 amino acids and are classified into different categories (for example, variable or V, and constant or C) according to their size and function. They have a characteristic immunoglobulin fold in which two β sheets create a "sandwich" shape, held together by interactions between conserved cysteines and other charged amino acids. There are five types of mammalian Ig heavy chain denoted by α, δ, ε, γ, and μ. The type of heavy chain present defines the isotype of antibody; these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies, respectively. Distinct heavy chains differ in size and composition; a and γ contain approximately 450 amino acids and δ approximately 500 amino acids, while μ and ε have approximately 550 amino acids. Each heavy chain has two regions, the constant region (CH) and the variable region (V_H). In one species, the constant region is essentially identical in all antibodies of the same isotype, but differs in antibodies of different isotypes. Heavy chains γ, a and δ have a constant region composed of three tandem Ig domains, and a hinge region for added flexibility; heavy chains μ and ε have a constant region composed of four immunoglobulin domains. The variable region of the heavy chain differs in antibodies produced by different B cells, but is the same for all antibodies produced by a single B cell or B cell clone. The variable region of each heavy chain is approximately 1 10 amino acids long and is composed of a single Ig domain.

In mammals, there are two types of immunoglobulin light chain denoted by λ and κ. A light chain has two successive domains: one constant domain (CL) and one variable domain (VL). The approximate length of a light chain is 21 1 to 217 amino acids. Each antibody contains two light chains that are always identical; only one type of light chain, K or λ, is present per antibody in mammals.

Although the general structure of all antibodies is very similar, the unique property of a given antibody is determined by the variable (V) regions, as detailed above. More specifically, variable loops, three each the light (VL) and three on the heavy (VH) chain, are responsible for binding to the antigen, i.e. for its antigen specificity. These loops are referred to as the Complementarity Determining Regions (CDRs). Because CDRs from both VH and VL domains contribute to the antigen-binding site, it is the combination of the heavy and the light chains, and not either alone, that determines the final antigen specificity. An "antibody fragment" contains at least one antigen binding fragment as defined above, and exhibits essentially the same function and specificity as the complete antibody of which the fragment is derived from. Limited proteolytic digestion with papain cleaves the Ig prototype into three fragments. Two identical amino terminal fragments, each containing one entire L chain and about half an H chain, are the antigen binding fragments (Fab). The third fragment, similar in size but containing the carboxyl terminal half of both heavy chains with their interchain disulfide bond, is the crystalizable fragment (Fc). The Fc contains carbohydrates, complement-binding, and FcR-binding sites. Limited pepsin digestion yields a single F(ab')2 fragment containing both Fab pieces and the hinge region, including the H-H interchain disulfide bond. F(ab')2 is divalent for antigen binding. The disulfide bond of F(ab')2 may be cleaved in order to obtain Fab'. Moreover, the variable regions of the heavy and light chains can be fused together to form a single chain variable fragment (scFv). Pharmaceutically acceptable salts are for example acid addition salts and basic salts. Acid addition salts are e.g. HCI or HBr salts. Basic salts are e.g. salts having a cation selected from alkali or alkaline, e.g. Na+, or K+, or Ca2+, or an ammonium ion

N+(R1 )(R2)(R3)(R4), wherein R1 to R4 independently of each other mean: hydrogen, an optionally substituted C1 -C6-alkyl group, an optionally substituted C2-C6-alkenyl group, an optionally substituted C6-C10-aryl group, or an optionally substituted C6-C10- heteroaryl group. Further examples of pharmaceutically acceptable salts are described in "Remington's Pharmaceutical Sciences" 17. ed. Alfonso R. Gennaro (Ed.), Mark Publishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia of Pharmaceutical Technology.

Pharmaceutically acceptable solvates are for example hydrates.

It will be further apparent to those skilled in the pertinent art that various

modifications and variations can be made to the present invention without departing from the spirit and scope of the invention . Further, it is to be noted, that any reference signs used in the appended claims are not to be construed as limiting the scope of the present invention . Brief Description of the Drawings

The following, preferred embodiments of the invention will be described by making reference to the drawings, in which:

Figure 1 schematically illustrates a drug delivery device in an exploded view, Figure 2 schematically shows the drug delivery device in longitudinal cross section, shows the interface between a body, cartridge holder and a protective cap according to Figure 2 in an enlarged view and shows a perspective view of the housing of a drug delivery device without protective cap.

Detailed Description

In Figure 1 , a drug delivery device 1 0 in form of a pen-type injector is schematically illustrated. The device 10 is of elongated or substantially tubular shape and comprises at least three housing components, a proximal body 14 and a distally located cartridge holder 16 to be directly interconnected with the body 14.

Moreover, a releasable protective cap 2 is provided to cover the cartridge holder 16, when the device 10 is not in use. The cartridge holder 16 is adapted to accommodate a cartridge 32 filled with a medicament. The cartridge 32 typically comprises a vial or carpule having a piercable seal at its distal end and further comprises a piston 33 to engage with a piston rod 30 of a drive mechanism 1 1 of the drug delivery device 10. By moving the piston rod 30 and hence the piston 33 in distal direction 1 , a well- defined amount of the medicament provided in the cartridge 32 can be dispensed via a needle assembly being not particularly illustrated in the present set of figures. Typically, a double-tipped needle assembly is to be removable screwed on a threaded socket 1 8 at the distal end of the cartridge holder 16. In order to inspect the filling level of the cartridge 32, which is preferably of vitreous type, the cartridge holder 1 6 comprises at least one inspection window 20.

In proximal d irection 2 or near its proximal end, the drug delivery device 1 0 comprises a dose dial 26 by way of which the dose to be dispensed by the device 1 0 can be individually set. By means of a dose button 28 to be depressed in distal direction 1 , an injection procedure may be initiated and controlled. Depending on the type of drive mechanism 1 1 , the general handling of the device 1 0 may vary and the device may comprise different components or members than the illustrated dose dial 26 or dose button 28 to set and/or to dispense a dose of the medicament. Hence, the housing as illustrated and described here can be universally adapted to a variety of drug del ivery devices and drive mechanisms.

The cartridge holder 16 and the body 14 are to be directly interconnected in a somewhat nested or interleaved way. For this purpose the cartridge holder 1 6 comprises an insert portion 22 at its proximal end to be inserted into a

correspondingly shape receptacle 24 at a distal end of the body 14. In distal direction 1 , the insert portion 22 is confined by a radially outwardly extending rim 23, which abuts with a distal end face of the body 14 when mutually assembled .

The piston rod 30, as further illustrated in Figures 2, is guided in a threaded insert piece 34 of the body 14 and further comprises a pressure piece 36 rotatably mounted on the distal end of the piston rod 30 by way of which distally directed thrust provided by the piston rod 30 can be transferred to a proximal thrust receiving face of the piston 33. However, axial position of the cartridge holder 16 may vary relative to the body 14. For not generating a gap 46 of variable size between the protective cap 12 and the body 14, the protective cap 12 is directly interconnectable with the body 14, as illustrated in Figures 2 and 3.

As illustrated there, the distally located receptacle 24 of the body 14 is provided with two distally extending snap members 40, that are adapted to engage with a correspondingly shaped radially inwardly extending snap member 44 of the protective cap 12. The snap members 40 of the body 14 as also illustrated in Figure 4 extend into the proximal portion of the cartridge holder 16, which comprises a radially inwardly extending recessed or stepped down portion 42 to accommodate and to receive the snap members 40. The radial extension of the recessed portion 42 and the snap members 40 is designed such, that the snap members 40 are at least slightly resiliently deformable in radial direction in order to positively engage with the corresponding snap members 44 of the protective cap 12. Additionally or alternatively, the corresponding snap members 44 of the protective cap 12 may also be resiliently deformable in radial direction.

Moreover, the recessed portion 42 of the cartridge holder 16 may also serve to at least provisionally engage the cartridge holder 16 with the body 14, e.g. after it has been slidably inserted in proximal direction 2 into the receptacle 24 of the body 14.

By providing a direct and mutual interconnection of protective cap 12 and body 14, a size of a circumferential gap 46 between the protective cap 12 and the body 14 can be reduced to a minimum, such that an almost seamless axial and/or radial abutment of protective cap 12 and body 14 can be obtained.

As further illustrated in Figures 2 and 3, the outer sidewall portion 13 near the proximal end of the protective cap 12 substantially flushes with the adjacently located distal outer sidewall portion 1 5 of the body, thereby providing a high- quality, substantially slit-free outer surface of the drug delivery device 10. List of Reference Numerals

1 distal direction

2 proximal direction

10 drug delivery device

11 drive mechanism

12 protective cap

13 sidewall portion

14 body

15 sidewall portion

16 cartridge holder

18 socket

20 inspection window

22 insert portion

23 rim

24 receptacle

26 dose dial

28 dose button

30 piston rod

32 cartridge

33 piston

34 insert

36 pressure piece

40 snap member

42 recessed portion

44 snap member

46 gap

Claims

1 . A housing of a drug delivery device to administer a predefined amount of a medicament, the housing comprising: a body (14) to accommodate a drive mechanism (1 1 ) having a piston rod (30) to operably engage with a piston of a cartridge (32) containing the medicament, a cartridge holder (16) to accommodate the cartridge (32), the cartridge holder (16) connectable with a distal end of the body (14), a protective cap (12) to cover the cartridge holder (1 6) and being directly releasably interconnectable with the body (14)

2. The housing according to claim 1 , wherein the protective cap (12) and the body (14) are positively engageable.

3. The housing according to any one of the preceding claims, wherein the body (14) comprises at least one resiliently deformable snap member (40) to engage with a corresponding snap member (44) of the protective cap (12).

4. The housing according to claim 3, wherein the body (14) and/or the cartridge holder (16) comprise a tubular shape and wherein the at least one snap member (40) of the body (14) and/or the snap member of (44) the protective cap (1 2) is deformable in radial direction .

5. The housing according to any one of the preceding claims 3 or 4, wherein the body (14) comprises at least two snap members (40) distributed along the circumference of the body and/or of the cartridge holder (1 6).

6. The housing according to any one of the preceding claims 3 to 5, wherein the protective cap (1 2) comprises a radially and circumferentially extending groove at an inside wall to mate with the at least one snap member (40) of the body (14).

7. The housing according to any one of the preceding claims, wherein the body (14) comprises a receptacle (24) at its distal end to receive an insert portion (22) of the cartridge holder (1 6).

8. The housing according to claim 3, wherein the at least one snap member (40) protrudes from a distal end of the body (14) in distal direction (1 ).

9. The housing according to any one of the preceding claims 3 to 8, wherein the cartridge holder (1 6) and/or its insert portion (22) comprises at least one recessed portion (42) to receive the at least one snap member (40) of the body (14).

10. The housing according to any one of the preceding claims, wherein the

cartridge holder (1 6) and the body (14) are inseparably connected .

1 1 . The housing according to any one of the preceding claims, wherein a

proximal outer side wall portion (1 3) of the protective cap (1 2) substantially flushes with an adjacently located distal outer side wall portion (1 5) of the body (14) when the protective cap (1 2) is interconnected with the body (14).

12. The housing according to any one of the preceding claims, wherein the

protective cap (1 2) substantially seamlessly abuts with a distal end of the body (14) when interconnected therewith .

13. A drug delivery device for administering a dose of a medicament, the device comprising : a drive mechanism (1 1 ) to operably engage with a piston (33) of cartridge (32), and a housing according to any one of the preceding claims.

The drug delivery device according to claim 13, further comprising a cartridge (32) arranged therein being at least partially filled with the medicament.