A medicament packaging assembly for installation in a medicament delivery device is disclosed. The packaging assembly comprises a cartridge having a medicament chamber, a sealing element for sealing a distal end of the medicament chamber, a sealing element release member, a cannula and a removable cap member. The assembly is switchable from a starting configuration in which the release member is spaced from the sealing element to an activated configuration in which the release member cooperates with the sealing element to connect the medicament chamber to the cannula. The packaging assembly further comprises a first chamber defined in part by the cap member and arranged for receiving the cannula such that at least a distal end of the cannula is sealed in the first chamber when the cap member is in place, and a second chamber defined in part by the sealing element and arranged for receiving the release member.