PRESSURISED INHALERS

摘要

A pressurised medicament canister has a valve which dispenses a metered dose upon being released from a depressed condition. An inhaler device adapted for use with the canister has a breath-actuated latch mechanism arranged in use to latch the canister in a depressed condition and further to release the latch in response to inhalation through the inhaler by a user. Additionally, a dose counter for counting the number of doses dispensed from the canister comprising a counter member having a helical toothed track which is incrementally advanced each time a dose is dispensed from the canister. Also a valve for the canister comprising a sliding seal delimiting the metering chamber and slidable relative to a nozzle member, said sliding seal being biased in use to reduce the volume of the metering chamber substantially to zero once the metering chamber has been vented to the atmosphere.