Medical delivery device

A medical delivery device, comprising

• a barrel assembly with a hollow interior and a first thread arrangement,
• a rod assembly with a second thread arrangement and a plunger rod element having a longitudinal axis and extending into the hollow interior of the barrel assembly, and
• a dosage chamber formed in the hollow interior of the barrel assembly with a variable volume limited by the plunger rod element of the rod assembly, and
• a rotation inhibiting formation,
• wherein the barrel assembly and the rod assembly are rotatable relative to each other, and
• wherein the first thread arrangement of the barrel assembly and the second thread arrangement of the rod assembly engage such that rotation of the barrel assembly and the rod assembly relative to each other moves the rod assembly along the longitudinal axis of its plunger rod element causing the volume of the dosage chamber to vary,
• wherein the rotation inhibiting formation is coupled to at least one of the barrel assembly and the rod assembly,
• wherein the rotation inhibiting formation defines an extra rotation resistance affecting rotation of the barrel assembly and the rod assembly relative to each other.