A pressurized refill canister containing a reservoir of composition including a propellant and a nicotine or a pharmaceutically acceptable derivative or salt thereof. The reservoir is at a pressure of greater than 400 kPa at 20° C. A refill outlet valve comprises a stem with an axial bore open at the axial end furthest from the reservoir to provide an outlet which discharges the composition in an axial direction. The stem 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.