A method of using a plug securing part for securing an end plug in a medicament container, the method comprising:
- providing the medicament container, the medicament container including a base body that at least partially surrounds an interior, the base body having a central axis and a proximal opening, wherein the medicament container forms a dual chamber system;
- arranging the end plug in the interior such that the end plug is displaceable along the central axis and, the end plug separates a first region of the interior from a second region of the interior, the first region being a distal region of the interior with respect to the end plug, the second region being a proximal region of the interior with respect to the end plug;
- inserting the plug securing part at least partially into the second region of the interior through the proximal opening, the plug securing part, when inserted into the interior, being closer to the proximal opening than the end plug, and held, at least in a holding area, in a fixed position in the interior by a connection selected from a positive connection, a non-positive connection and a combination thereof, wherein the plug securing part is inserted into the second region through the proximal opening so that it is positioned closer to the proximal opening than the end plug, wherein the plug securing part is held at least in a holding area of the second region of the medicament container by the positive connection and/or the non-positive connection;
- holding the plug securing part onto the base body when inserted into the interior by at least one elastic holding element of the plug securing part, the at least one elastic holding element having an elasticity acting on the central axis at least radially, and
- subjecting the medicament container to a pressure gradient by a change in altitude and retaining the plug within the medicament container with the plug securing part.