Method for manufacturing a composite work piece for a drug delivery device and composite work piece for a drug delivery device

Abstract

Method for manufacturing a composite work piece for a drug delivery device, comprising the steps: Providing a first work piece part 1 and a second work piece part 2, arranging both work piece parts 1, 2 with respect to each other in such a way that both work piece parts 1, 2 are in mechanical contact with one another in a contact area 3, irradiating a surface of the first work piece part 1 with electromagnetic radiation, thereby softening the first work piece part 1 and/or the second work piece part 2 in a region adjacent to the contact area 3, and joining the first work piece part 1 to the second work piece part 2 in the contact area 3 for the composite work piece. Furthermore, a composite work piece for a drug delivery device is provided.

Claims

1. A method for manufacturing a composite work piece for a drug delivery device, comprising the steps: A) providing a first work piece part and a second work piece part, the first work piece part and the second work piece part being chosen in a way that they both comprise a plastic, wherein the first work piece part comprises a semi-tubular shaped spring comprising a first and a second slot contact area, and the second work piece part comprises a semi-tubular shaped spring comprising a first and second wing, B) arranging both work piece parts with respect to each other in such a way that both work piece parts are in mechanical contact with one another in a contact area by an elastic force that is exerted by one of the work piece parts on the other one of the work piece parts by way of an elastic deformation, such that the first and second wings of the second work piece part are pressed on the first and second slot contact areas of the first work piece part, respectively, by the elastic force, C) irradiating a surface of the first work piece part with electromagnetic radiation, thereby softening the first work piece part and/or the second work piece part in a sub-area of the contact area, and D) joining the first work piece part to the second work piece part in the contact area for the composite work piece, such that, after completing the step of joining the first work piece part to the second work piece part, the contact area comprises (i) a weld, which permanently connects the first work piece part to the second work piece part and (ii) an unwelded sub-area adjacent to the weld, wherein in the unwelded sub-area the first and the second part are under elastic residual stress, wherein a residual elastic restoring force is exerted by one of the works piece parts onto the other one of the work piece parts on account of a residual elastic deformation of one of the work piece parts, wherein for the first work piece part a part is used which is impervious for the electromagnetic radiation of step C) and absorbs the electromagnetic radiation of step C) to an extent sufficient for softening the first work piece part and/or the second work piece part.

2. Method according to claim 1, wherein in step B) the work piece parts are connected to one another via a force-fit connection.

3. Method according to claim 1, wherein the first work piece part comprises a black pigment.

4. Method according to claim 1, wherein in step B) the second work piece part is introduced at least partly into the first work piece part, whereby the work piece parts are brought in mechanical contact with one another in the contact area.

5. Method according to claim 1, wherein a laser is used for irradiating the surface of the first work piece part in step C).

6. Method according to claim 1, wherein the composite work piece is formed during production of a drug delivery device, the device being an injection pen.

7. Method for manufacturing a drug delivery device comprising joining a first work piece part and a second work piece part according to the method of claim 1.

8. A method for manufacturing a composite work piece for a drug delivery device, comprising the steps: A) providing a first work piece part and a second work piece part, B) arranging both work piece parts with respect to each other in such a way that both work piece parts are in mechanical contact with one another in a contact area, C) irradiating a surface of the first work piece part with electromagnetic radiation, thereby softening the first work piece part and/or the second work piece part in a region adjacent to the contact area, wherein a surface of the first work piece part is irradiated which is on that side of the first work piece part remote from the second work piece part, and D) joining the first work piece part to the second work piece part in the contact area for the composite work piece, wherein for the first work piece part a part is used which is impervious for the electromagnetic radiation of step C) and absorbs the electromagnetic radiation of step C) to an extent sufficient for softening the first work piece part and/or the second work piece part.

9. The method of claim 8, wherein before step C) and after step B), the first work piece part and the second work piece part are held in mechanical contact with each other in the contact area by a force.

10. The method of claim 9, wherein the force is an elastic restoring force, which is exerted by one of the work piece parts onto the other one of the work piece parts on account of a residual elastic deformation of one of or both of the work piece parts.

11. A drug delivery device comprising: a composite work piece, wherein the composite work piece comprises: a first work piece part, wherein the first work piece part is impervious to an electromagnetic radiation, a second work piece part, wherein the first work piece part comprises a semi-tubular shaped spring comprising a first and a second slot contact area, and the second work piece part comprises a semi-tubular shaped spring comprising a first and second wing, wherein the first work piece part and the second work piece part are in mechanical contact with one another in a contact area by an elastic force that is exerted by one of the work piece parts on the other one of the work piece parts by way of an elastic deformation, such that the first and second wings of the second work piece part are pressed on the first and second slot contact areas of the first work piece part, respectively, by the elastic force, wherein the contact area comprises a weld, which permanently connects the first work piece part to the second work piece part, and wherein the contact area comprises an unwelded sub-area adjacent to the weld, wherein in the unwelded sub-area the first and the second part are under elastic residual stress, wherein a residual elastic restoring force is exerted by one of the work piece parts onto the other one of the work piece parts on account of a residual elastic deformation of one of the work piece parts.

Description

(1) The following figures are for illustrating some embodiments of the composite work piece and of the method from manufacturing the composite work piece.

(2) FIGS. 1a-c show in a schematic cross section three different steps of the manufacturing process of one embodiment of the composite work piece,

(3) FIGS. 2a-d show a schematic cross section of four different steps of the manufacturing process of another composite work piece,

(4) FIG. 3 shows an exemplary embodiment of a drug delivery device.

(5) FIG. 1a schematically shows the cross section of a first work piece part 1 and a second work piece part 2. Both parts 1, 2 have a tubular or sleeve-like form in this embodiment. The first work piece part 1, which may be circumferentially closed, is shown schematically with a window that allows to view the inside of it, which may be a hollow. The window may be present in the first work piece part 1 or may be for allowing to view the inside of the part 1 for illustration purpose only.

(6) In this embodiment, the second work piece part 2 has a constant inner diameter. The outer diameter of the second work piece part 2 may vary. The second work piece part 2 comprises one or more protrusions 6 at its outer surface. The respective protrusion 6 may be a flange or the protrusions 6 may comprise one or more protruding ribs. Therefore, the outer diameter of the second work piece part 2 is greater in the section with the protrusion 6 than in other sectors with respect to the top and bottom of the part 2. The section with the protrusions 6 may be a central or mid section of the first work piece part 1. The outer diameter at the bottom and at the top of the second work piece part 2 is smaller compared to the central section.

(7) FIG. 1b shows a schematic cross section for example for the method step B) as described previously. The first work piece part 1 and the second work piece part 2 are now arranged with respect to each other for being joined by introducing the second work piece part 2 into the first work piece part 1. Both parts 1, 2 are in contact with another in the contact area 3. In this embodiment the contact area 3 is only a sub-area of the overlap between the first work piece part 1 and the second work piece part 2. The outer diameter of the second work piece part 2 is greater in the area of the protrusions 6 than the inner diameter of the first work piece part 1. Therefore an external force is required to push the second work piece part 2 into the first work piece part 1. The outer diameter of the protrusions 6 is matched to the inner diameter of the first part 1 in a way that the second work piece part 2 can be introduced into the first work piece part 1 and, additionally, that the two parts 1, 2 are pressed to each other by an elastic restoring force in the contact area. This force is exerted by the work piece parts 1, 2 onto one another, in general on account of a residual elastic deformation of one of the work piece parts 1, 2 or both work piece parts in the contact area 3. In the area of the outer surface of the second work piece part 2 with the smaller outer diameter the first work piece part 1 and the second work piece part 2 are not under elastic stress. In this area there may be no force pressing the two work piece parts 1, 2 against each other.

(8) FIG. 1c shows a schematic cross section of another manufacturing step which may be step C) as previously discussed for example. In this manufacturing step the surface of the first work piece part 1 is irradiated by a laser beam. The laser passes through the first work piece part 1 and reaches the second work piece part 2. The laser radiation may be absorbed in the second work piece part 2. The laser may be focused on an area of the surface of the first work piece part 1 so that it impacts the second work piece part 2 in the contact area 3 after passing through the first work piece part 1. So, the energy of the laser beam may be absorbed by the second work piece part 2. The absorbed energy may now soften the surface of the second work piece part 2, which is in direct contact with the first work piece part 1. The second work piece part 2 may be heated through the absorbed laser energy and the heat may be transferred to the first work piece part 1, so that also the first work piece part 1 may be softened. If both work piece parts 1, 2 are softened until they melt, the materials of the both work piece parts 1, 2 are able to mix.

(9) The laser may be directed only at selected points onto the surface of the first work piece part. Thereby, pointwise welds may be created. It is also possible that the laser is guided around the whole first work piece part 1 in a way, such that a continuous weld is formed which may run circumferentially around the former second work piece part 2 in the contact area 3.

(10) Because of the elastic restoring force which presses the first work piece part 1 and the second work piece part 2 against each other before they have been softened, no additional external force is necessary to achieve a good joining strength between the first work piece part 1 and the second work piece part 2. Therefore, a good joining is possible, for example just by softening one or two or more points in the contact area 3 and curing the softened material. After curing, the first work piece part 1 and the second work piece part 2 are now permanently and firmly connected in a way that the connection is resistant to mechanical stress.

(11) FIG. 2a shows a schematic cross section of another embodiment of the first work piece part 1. In this embodiment the first work piece part 1 is a spring member with a semi-tubular form. The spring member has a section provided for forming the contact areas 3 at the left and at the right end in the inner side of the first work piece part 1. The first work piece part 1 may be part of a drug delivery device 7 (see FIG. 3), e.g. part of a housing sleeve 8 of the device 7.

(12) FIG. 2b shows a schematic cross section of an embodiment of the second work piece part 2. Also the second work piece part 2 is a spring member. As compared to the first work piece part 1 which is shown in FIG. 2a it additionally comprises two wings at opposing ends of the spring member. These two wings, especially the outer surface of these two wings, are matched in a way to the first work piece part 1 that they may get into connection with the first part and form the contact area 3 at the outer side of the wings. The second work piece part 2 may be part of the drug delivery device 7 (see FIG. 3), in particular an other part of the housing sleeve 8 of the device 7.

(13) FIG. 2c shows a schematic cross section of a composite work piece which may be manufactured for example by arranging the first work piece part 1 which is shown in FIG. 2a and the second work piece part 2 which is shown in FIG. 2b with respect to each other in a way that they form a tube. Both parts 1, 2 are arranged in this embodiment so that the wings of the second work piece part 2 are introduced into the first work piece part 1, for example in corresponding slots thereof, and that the outer side of the respective wing is in contact with the inner surface of the first work piece part 1. The wings of the second work piece part 2 and the corresponding area at the inner surface of the first part 1 are pressed on each other by a force, which may be an elastic restoring spring force.

(14) FIG. 2d shows a schematic cross section of another embodiment of the composite work piece after an additional manufacturing step. In this embodiment the first work piece part 1 has been irradiated with electromagnetic radiation, for example by a laser, in a pre-determined preferably small area of the outer surface of the first work piece part 1. This surface is located on the opposite side from the inner surface of the first work piece part 1 which is in contact with the wings of the second work piece part 2. The energy of the laser beam is absorbed by the first work piece part 1, whereby the first work piece part 1 is softened in a sub-area of the contact area 3. After hardening a weld 4 was formed in the contact area 3, which weld 4 now permanently connects the first work piece part 1 with the second work piece part 2. The weld 4 does not occupy the whole contact area 3 such that there is a sub-area 5 of the contact area 3 left adjacent to the weld 4, in which both parts 1, 2 are not welded to each other. In this sub-area 5, both parts 1, 2 may be still under elastic stress because of the elastic restoring force and, thus, may apply pressure on each other.

(15) In an alternative embodiment, a first work piece part may be introduced partly into a second work piece part, in particular a hollow space thereof. In this case, the minimum inner diameter of the second work piece part matches or is less than the maximum outer diameter of the first work piece part.

(16) In this embodiment, the electromagnetic irradiation is emitted from a hollow space inside of the first work piece part, the electromagnetic irradiation being directed essentially radially outward.

(17) FIG. 3 shows exemplary embodiment of a drug delivery device 7. The drug delivery device 7 may comprise one or more composite work pieces (not explicitly shown) formed as described in connection with FIGS. 2a through 2d, for example.

(18) The drug delivery device 7 may be an injection device. The drug delivery device 7 may be a pen-type device, in particular a pen-type injector. The device 7 may be a disposable or a re-usable device. The device 7 may be configured to dispense fixed doses of a drug, in particular doses which may not be varied by the user, or variable, preferably user-settable, doses of the drug. The drug delivery device 7 may be a manually, in particular a non-electrically, driven device.

(19) The drug delivery device 7 comprises a housing 8. The housing 8 comprises a tubular shape. In particular, the housing 8 may comprise or may be embodied as a sleeve. The housing 8 is configured to house members of the drug delivery device 7, e.g. a guide member (not explicitly shown), a drive member (not explicitly shown) and/or a dose member 11. Preferably, these members comprise a tubular shape. In particular, these members may comprise or may be embodied as a sleeve. The tubular shape of the respective members of the device 7 makes these members especially suitable for acting as the first work piece part and/or the second work piece part and, hence, for being joined forming the previously described composite work pieces. In particular, the housing sleeve 7 may comprise a composite work piece formed by the joined of a first housing part and a second housing part (not explicitly shown). Additionally or alternatively, the dose member 11 may comprise a composite work piece.

(20) Furthermore, the device 7 may comprise the previously mentioned guide member, in particular a guide sleeve (not explicitly shown). This member may be arranged inside the housing 8. In particular, the guide sleeve may be permanently secured to the housing 8, in particular secured against axial and rotational movement with respect to the housing. The housing 8 may, in this case, form a first work piece part. The guide member may form a second work piece part. The permanent joined connection of the housing 8 and the guide member may comprise a composite work piece of the device 7.

(21) The drug delivery device 7 comprises a cartridge holder 9. The cartridge holder 9 is connected, preferably releasably connected, to the housing 8 of the device 7. The device 7 comprises a cartridge 10. The cartridge 10 is retained in the cartridge holder 9. The cartridge holder 9 stabilizes the cartridge 10 mechanically. The cartridge 10 may hold a plurality of doses of a drug. The term drug, as used herein, preferably 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 protein, a polysaccharide, a vaccine, a DNA, a RNA, a antibody, an enzyme, an antibody, a hormone or an oligonucleotide, or a mixture of the above-mentioned pharmaceutically active compound.

(22) 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.

(23) 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.

(24) 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 exedin-3 or exedin-4 or an analogue or derivative of exedin-3 or exedin-4.

(25) 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.

(26) Insulin derivatives 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; B29-N-(-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(-carboxyheptadecanoyl) human insulin.

(27) 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-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

(28) Exendin-4 derivatives are for example selected from the following list of compounds:

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

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

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

(32) des Pro36 [IsoAsp28] Exendin-4(1-39),

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

(34) des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

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

(36) des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

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

(38) des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or

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

(40) des Pro36 [IsoAsp28] Exendin-4(1-39),

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

(42) des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

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

(44) des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

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

(46) des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),

(47) wherein the group -Lys6-NH2 may be bound to the C-terminus of the Exendin-4 derivative;

(48) or an Exendin-4 derivative of the sequence

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

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

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

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

(53) des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

(70) H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,

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

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

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

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

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

(76) H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2;

(77) or a pharmaceutically acceptable salt or solvate of any one of the afore-mentioned Exedin-4 derivative.

(78) 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.

(79) 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.

(80) Pharmaceutically acceptable salts are for example acid addition salts and basic salts. Acid addition salts are e.g. HCl 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.

(81) Pharmaceutically acceptable solvates are for example hydrates.

REFERENCE NUMERALS

(82) 1) first work piece part

(83) 2) second work piece part

(84) 3) contact area

(85) 4) weld

(86) 5) unwelded sub-area

(87) 6) protrusion

(88) 7) drug delivery device

(89) 8) housing

(90) 9) cartridge holder

(91) 10) cartridge

(92) 11) dose member