A cartridge for an inhaler

A cartridge for an inhaler, comprising:

• an inner cartridge assembly comprising a bottle and a collapsible bag, the bag configured to contain a volume of liquid, the bottle and bag mutually configured so that the bag is contained within the bottle, the bottle further comprising a container hole configured to allow gases to pass between the interior and exterior of the bottle;
• an outer casing configured to contain the inner cartridge assembly, the inner cartridge assembly sealed within the outer casing, the outer casing comprising a vent hole passing through the casing from the exterior to the interior to allow gases to pass into the outer casing;
• a sealing assembly configured to close and seal the vent hole, the sealing assembly having an open position that allows the passage of gases through the vent hole, and a closed position where the sealing assembly seals the vent hole, the sealing assembly configured so that when the cartridge is used in an inhaler, actuating the inhaler temporarily opens the sealing assembly to allow the passage of gases therethrough;
• the outer casing and inner cartridge assembly further configured so that there is a gas path inside the cartridge between the container hole and the vent hole.