A pressurised refill canister 5 containing a reservoir 31 of composition including a propellant and a nicotine or a pharmaceutically acceptable derivative or salt thereof. The reservoir 31 is at a pressure of greater than 400k Pa at 20oC. A refill outlet valve 20 comprises a stem 6 with an axial bore 24 open at the axial end furthest from the reservoir 31 to provide an outlet which discharges the composition in an axial direction. The stem 6 is displaceable from a closed position to which it is biased by a first resilient member with a spring force of greater than 10N when no external force is applied to a dispensing position against the action of the first resilient member to open a flow path from the reservoir to the outlet.
