Sanofi
Drug Delivery Device

Abstract:

A drug delivery device comprising a housing body; a piston rod configured to rotate in a first direction during dose dispensing under a driving force; and a threaded insert, wherein the piston rod is in threaded engagement with the threaded insert such that during dose dispensing, the piston rod displaces axially in a distal direction relative to the threaded insert for displacement of a cartridge bung. The threaded insert is movable relative to a stop provided in the housing body and a resilient means is provided to bias the threaded insert against the stop so that rotation of the piston rod causes the threaded insert to move away from the stop in response to reaction forces acting on the piston rod (in a proximal direction when the reaction forces exceed the biasing force of the resilient means.