Training cartridge for a drug delivery device

A drug delivery device for dispensing of a dose of a medicinal fluid, comprising:

• a housing,
• a cartridge holder,
• a drive mechanism and
• a cartridge comprising:
• a body of substantially cylindrical shape,
• a piston slidably disposed in the body in an axial direction,
• a closure means disposed at an axial end portion of the body
• wherein the body, the piston and the closure means confine an interior volume coupled to the exterior via at least one fluid escape channel,
• wherein the at least one fluid escape channel is designed as a groove in a contact surface of the interface section of body and/or closure means, and
• wherein the cartridge is disposed in the cartridge holder and wherein the cartridge is operably engageable with the drive mechanism.

A method of resetting a cartridge for a drug delivery device,

• wherein the cartridge comprises
• a body of substantially cylindrical shape,
• a piston slidably disposed in the body in an axial direction and
• a closure means disposed at a first axial end portion of the body,
• wherein the body, the piston and the closure means confine an interior volume coupled to the exterior via at least one fluid escape channel,
• wherein after the piston reaching a distal stop position in the vicinity of the closure means;
• the method of resetting of the cartridge comprises the steps of:
• detaching the closure means from the first end portion of the body and
• arranging the closure means at a second end portion of the body opposite the first end portion.