Drug Delivery

The present invention relates to an apparatus for ejecting target mass. In particular, but not exclusively, the present invention provides an apparatus for a fast mass ejection device able to eject liquid and/or liquid vapour quickly and over relatively long distances from an ejection chamber in which a quantity of liquid is stored. The present invention also relates to the many uses of such an ejection system. Still more particularly, but again not exclusively, the present invention relates to an inhaler and/or nebulizer and/or needleless injector which are able to deliver drugs to a user.