Drug delivery device

A drug delivery device comprising a transdermal delivery system having a needle actuation mechanism and a needle assembly comprising a needle connected to a needle holder, a cannula connected to a cannula holder, and a guiding element configured to guide axial displacement of the needle and the cannula, the needle actuation mechanism comprising a cam member having a cam housing and a spring housed inside the cam housing in order to impart rotational movement to the cam member relative to the needle guiding element, said needle and cannula holders comprising each an engagement portion, wherein the engagement portion of the needle holder is configured to engage with a first and a second cam surface and the engagement portion of the cannula holder is configured to engage with a locking surface, the first and second cam surfaces being arranged around the circumference of an outer surface of the cam housing along a first portion with a first gradient configured for the needle insertion movement followed by a second portion with a second gradient configured for the needle retraction movement such that the needle and the cannula are moved from a retracted position to an extended position upon rotation of the claim member through a first predetermined angle, and such that the needle is brought back in the retracted position upon further rotation of said cam member through a second predetermined angle, whereby during rotation through said second predetermined angle, the engagement portion of the cannula holder abuts against the locking surface to maintain the cannula in the extended position configured for transdermal delivery.

Method for reconstituting a drug using a pump system comprising a pump drive and a pump having a pump housing comprising first and second ports and an outlet port, the pump housing forming a pump chamber containing a pump piston and a valve piston, wherein the pump comprises a valve channel configured to selectively connect and disconnect at least one of the first and second ports to the pump chamber as a function of the position of the valve piston and wherein the valve piston and the pump piston are independently actuated, the method comprising the following steps:

• i) setting the valve piston in a first axial position in which the first and second ports of the pump housing are in fluid communication;
• ii) urging a first constituent contained in a first container through the valve channel into a second container containing substance second constituent in order to reconstitute the drug inside the second container during a drug reconstitution phase;
• iii) driving the pump piston away from the valve piston along the pump axis to draw the reconstituted drug from the second container into the pump chamber during a chamber filing phase;
• iv) driving the valve piston in a second axial position, upon completion of the chamber filling phase, in which the valve channel is aligned with the outlet port while the first and second ports are closed by the valve piston;
• and
• v) driving the pump piston towards the piston valve along the pump axis to expel the reconstituted drug from the pump chamber, through the valve channel and the outlet port during a drug administration phase.