Housing part for an auto-injector

1. A housing part for an auto-injector comprising:

a shell form body defining inner and outer shell surfaces;

an over-coating, said over-coating covering at least part of said outer shell surface of said shell form body; and

at least one window defined in the shell form body, wherein said over-coating extends into said at least one window,

wherein a material forming the over-coating is softer than or is more compressible than a material forming the shell form body, and

wherein the over-coating extends into the window beyond a depth of the inner shell surface to define an inwardly protruding element,

wherein the inwardly protruding element is configured to be disposed between the shell form body and at least one functional element to be disposed within the housing part so as to provide impact protection for the at least one functional element within the housing part,

wherein the inner shell surface adjacent the at least one window is free of said over-coating.

2. The housing part according to claim 1 , wherein the over-coating is provided as an over-moulding to the shell form body.

3. The housing part according to claim 1 , wherein the shell form body has a clam shell form.

4. The housing part according to claim 3 , wherein the shell form body has a cylindrical or ellipsoidal clam shell form.

5. The housing part according to claim 1 , wherein the housing part defines a rearward part of a housing for an auto-injector.

6. The housing part according to claim 5 , wherein the at least one window is provided towards a rear end of the rearward part of the housing.

7. The housing part according to claim 1 , wherein the shell form body comprises an acrylonitrile butadiene styrene material.

8. The housing part according to claim 1 , wherein the over-coating comprises a thermoplastic elastomer material.

9. The housing part according to claim 8 , wherein the thermoplastic elastomer material is selected from styrene-ethylene/butylene-styrene (SEBS) block copolymers, Styrene-Ethylene/Propylene-Styrene (SEPS) block copolymers, Styrene-Butadiene-Styrene (SBS) and thermoplastic vulcanisates (TPV) incorporating vulcanised rubber inclusions.

10. The housing part according to claim 1 , wherein the over-coating is comprised of a material that has a hardness of from 20 Shore A to 60 Shore A.

11. An auto-injector device comprising the housing part according to claim 1 , wherein said auto-injector device comprises a syringe.

12. The auto-injector according to claim 11 , wherein the syringe contains a liquid drug formulation.

13. The auto-injector according to claim 12 , wherein a barrel of said syringe has a volume corresponding to a single dose of said liquid drug formulation.

14. The auto-injector according to claim 13 , wherein the liquid drug formulation comprises an aqueous formulation of a therapeutic biologic type drug.

15. The housing part according to claim 1 , wherein the inwardly protruding element is configured to deform upon impact so as to provide impact protection for the at least one functional element to be disposed within the housing part.

16. The housing part according to claim 1 , wherein the inwardly protruding element extends inwardly to only a partial depth of a cavity defined by the shell form body.

17. A housing part for an auto-injector comprising;

a shell form body defining inner and outer shell surfaces, the shell form body forming a cavity for the disposition of one or more functional elements of the auto-injector within the housing part;

an over-coating, said over-coating covering at least part of said outer shell surface of said shell form body and configured to provide impact protection to at least the shell form body;

wherein a material forming the over-coating is softer than or is more compressible than a material forming the shell form body;

at least one window defined in the shell form body,

wherein a portion of said over-coating extends into said at least one window, the portion configured to enhance a bond between the over-coating and the shell form body;

wherein the portion of said over-coating extends into the cavity away from and beyond a depth of the inner shell surface to define an inwardly protruding element;

wherein the inwardly protruding element is configured to be disposed between the shell form body and at least one of said one or more functional elements disposed within the housing part so as to provide impact protection for the one or more functional elements within the housing part; and

wherein the inwardly protruding element is not in direct contact with the inner shell surface, when the inwardly protruding element is not compressed.

18. A housing part for an auto-injector comprising:

a shell form body defining inner and outer shell surfaces and comprising at least one window defined in the shell form body;

an over-coating, the over-coating covering at least part of the outer shell surface of the shell form body and extending into the at least one window;

wherein the shell form body defines a cavity for the disposition of one or more functional elements of the auto-injector therein;

wherein a material forming the over-coating is softer than or is more compressible than a material forming the shell form body;

wherein the over-coating is configured to deform upon impact so as to provide impact protection to at least the shell form body;

a portion of the over-coating extends into the cavity to define an inwardly protruding element;

wherein the inwardly protruding element is configured to deform upon impact so as to provide additional impact protection to the one or more functional elements;

wherein the at least one window comprises a width, a length, and a depth; and

wherein a width and a length of the inwardly protruding element are equal to or less than the respective width and the length of the at least one window.