Autoinjector with shock reducing elements

A damper mechanism for an injection device having a drug storage container including a stopper movably disposed in the container, and a plunger for acting on the stopper, the damping mechanism for reducing a velocity of the plunger prior to acting on the stopper, the damper mechanism comprising:

• a housing having an end wall with an inner surface facing the stopper;
• a piston assembly movable in the housing between a first position spaced from the inner surface of the end wall of the housing and a second position engaging the inner surface of the end wall of the housing and acted upon by a plunger of the injection device;
• and
• a working fluid displaceable by the piston assembly for resisting movement of the plunger;
• wherein the piston assembly being disposed in the second position causes the plunger to act on the stopper to move the stopper within the container.

A method for administering a drug comprising:

• providing a container containing a drug and a stopper movably disposed in the container for expelling the drug;
• acting on the stopper with a plunger driven by an energy source that exerts a force on the plunger, the force causing the plunger to accelerate to a velocity prior to acting on the stopper;
• and
• reducing the velocity of the plunger with a damping mechanism prior to acting on the stopper, the damping mechanism comprising a piston assembly movable in a housing between a first position spaced from an end wall of the housing and a second position engaging the end wall of the housing and acted upon by the plunger, and a working fluid displaceable by the piston assembly for resisting movement of the plunger;
• wherein acting on the stopper with the plunger comprises driving the stopper within the container with the piston assembly in the second position.