Nasal delivery device for a powder

A nasal powder dispenser device comprising:

• a reservoir containing at least one dose of powder;
• a nasal dispenser head for inserting into a user's nostril, said nasal dispenser head including a dispenser orifice said reservoir being formed by a hollow tube closed at a proximal end of the hollow tube by a closure element when said closure element is in a closed position and closed at a distal end of the hollow tube by an insert, said insert including a rod-forming axial extension, said insert, during actuation, sliding in said hollow tube so as to expel said closure element out from the closed position of the closure element;
• and an air expeller that, during actuation of said nasal powder dispenser device, generates a flow of compressed air so as to dispense a dose of powder into said nostril through said dispenser orifice, said air expeller comprising an air chamber and a piston that slides in airtight manner in said air chamber so as to compress the air contained in said air chamber;
• said piston being secured to an axial projection that extends in the proximal direction, and that, during actuation, moves together with said piston while the air contained in said air chamber is being compressed, such that, when said projection of said piston comes into contact with said insert of said reservoir, a continuation of movement of said piston causes said insert to slide in said hollow tube out from a closed position of said insert, such that said insert firstly opens a passage between said air expeller and the reservoir, and secondly causes said closure element to be expelled,
• wherein said nasal powder dispenser device presents the following properties:
• a pressure, of said flow of compressed air generated by said air expeller, that is higher than 0.7 bar and lower than 2 bar;
• and
• a volume, of said air chamber, that is greater than 1700 mm3 and smaller than 3000 mm3.