Pen needle magazine

1. An attachable needle assembly for use on a medication delivery pen, the needle assembly comprising:

a needle assembly housing that moves between a first position and a second position, the needle assembly housing surrounding:

a rotating ratchet that includes a needle assembly septum having a septum cavity; and

a plurality of needles configured to open the needle assembly septum,

wherein

when the needle assembly housing is in the first position, the plurality of needles are disengaged from the needle assembly septum, and when the needle assembly housing is in the second position, one of the plurality of needles enters into fluid communication with the septum cavity and is exposed for medicament delivery; and

when the needle assembly housing moves from the first positon to the second position, the rotating ratchet rotates to align the septum cavity with one of the plurality of needles.

2. The attachable needle assembly of claim 1 , further comprising

a spring applying a compression force to the needle assembly septum, wherein

when the needle assembly housing is released from the second position, the spring returns the needle assembly housing to the first position.

3. The attachable needle assembly of claim 2 , further comprising

a needle retriever including a flange, the needle retriever surrounding the plurality of needles, wherein

the spring causes the flange to contact the needle assembly housing in the first position to maintain constant compression of the spring.

4. The attachable needle assembly of claim 1 , further comprising

a main housing disposed in the needle assembly housing, the main housing including a first curvilinear path, wherein

the rotating ratchet includes a follower comprised of angled surfaces; and

the follower travels along the first curvilinear path to rotate the rotating ratchet as the needle assembly housing is moved between the first position and the second position so that a different needle of the plurality of needles opens the septum cavity each time the needle assembly housing is in the second position.

5. The attachable needle assembly of claim 4 , wherein the needle assembly housing moves axially relative to the main housing.

6. The attachable needle assembly of claim 4 , wherein the needle assembly housing includes a second curvilinear path that cooperates with the first curvilinear path and guides the follower of the rotating ratchet to rotate.

7. The attachable needle assembly of claim 1 , wherein when the needle assembly housing is in the second position, a remainder of the plurality of needles enters into a hollow opening in the rotating ratchet.

8. The attachable needle assembly of claim 1 , wherein when the one needle of the plurality of needles returns from the second position to the first position, the one needle of the plurality of needles is unable to be reused.

9. The attachable needle assembly of claim 1 , further comprising

a plurality of needle posts that each secures one of the plurality of needles; and

a needle housing that stores each of the plurality of needle posts, wherein

the plurality of needle posts is engaged to the needle housing in the first and second positions of the needle assembly housing.

10. The attachable needle assembly of claim 1 , wherein

each needle of the plurality of needles is secured in a respective needle post, and

when the needle assembly housing moves from the first position to the second position, the needle post of the one needle moves from a top position to a bottom position in a needle housing to expose the one needle for medicament delivery.

11. The attachable needle assembly of claim 10 , wherein when the needle assembly housing moves from the first position to the second position, a remainder of the plurality of needles extends further into a hollow opening of the rotating ratchet.

12. The attachable needle assembly of claim 1 , wherein

a proximal end of the plurality of needles is each enclosed by a first sterility boot when the needle assembly housing is in the first position, wherein

when the needle assembly housing is in the second position, the first sterility boot of the one needle of the plurality of needles is opened to establish fluid communication between the one needle and the septum cavity of the needle assembly septum.

13. The attachable needle assembly of claim 1 , wherein

a distal end of the plurality of needles is each enclosed by a second sterility boot when the needle assembly housing is in the first position, wherein

when the needle assembly housing is in the second position, the second sterility boot of the one needle of the plurality of needles is opened to expose the one needle for medicament delivery.

14. The attachable needle assembly of claim 13 , wherein

each second sterility boot lies at a bottom interior surface of a needle housing.

15. The attachable needle assembly of claim 1 , wherein the plurality of needles does not open a reservoir septum of the medication delivery pen.

16. The attachable needle assembly of claim 1 , wherein the plurality of needles does not substantially rotate or substantially move radially.

17. The attachable needle assembly of claim 1 , wherein the plurality of needles includes eight needles.

18. The attachable needle assembly of claim 1 , wherein the needle assembly housing moves from the first position to the second position by traveling away from the medication delivery pen.

19. The attachable needle assembly of claim 1 , further including

a cover enclosing the needle assembly; and

a label sealing the needle assembly in the cover and maintaining sterility prior to operating with the medication delivery pen.

20. A method of operating an attachable needle assembly on a medication delivery pen, the needle assembly comprising a needle assembly housing surrounding (1) a rotating ratchet including a needle assembly septum having a septum cavity and (2) a plurality of needles configured to open the needle assembly septum, the method comprising:

moving the needle assembly housing from a first position to a second position;

rotating the rotating ratchet to align one of the plurality of needles to the septum cavity;

establishing fluid communication between the septum cavity and the one of the plurality of needles for medicament delivery;

moving the needle assembly housing from the second position to the first position;

ending fluid communication between the septum cavity and the one of the plurality of needles; and

rotating the rotating ratchet to begin aligning a subsequent needle of the plurality of needles to the septum cavity.