A reconstitution assembly includes: a flexible bag containing a diluent a drug vial containing a drug a reconstitution device further comprising: a first sleeve connected to the first container a second sleeve connected to the second container, the second sleeve being associated with the first sleeve and movable axially with respect thereto from an inactivated position to an activated position a piercing member positioned in the sleeves, the piercing member providing a fluid pathway between the bag and vial when the sleeves are in the activated position.
