Inhalation device for producing a drug aerosol

A device for delivering a drug by inhalation, comprising:

• a) a chamber having upstream and downstream ends;
• b) a drug supply unit that produces drug vapor in a region of said chamber between said upstream and downstream ends;
• c) an upstream orifice communicating with said chamber upstream of said region that limits gas flow from a user's breath intake through said region to a selected flow rate or flow rate range, effective to condense said drug vapor to form an aerosol;
• d) a bypass orifice communicating with said chamber downstream of said region that allows gas to enter said chamber under conditions of inhalation actuated selected pressure differential across said bypass orifice;
• and
• e) an actuation switch for causing said drug supply unit to produce drug vapor.

A device for delivering a drug by inhalation, comprising:

• a) a chamber having upstream and downstream openings;
• b) a drug supply unit that produces a drug vapor in communication with a condensation region of said chamber between said upstream and downstream openings;
• c) a gas-flow control valve upstream of said drug supply unit that allows gas from a user's breath intake to enter said condensation region at a selected flow rate or flow rate range to produce a condensation aerosol of a select particulate size range;
• d) a bypass orifice communicating with said chamber downstream of said gas-flow control valve at a location that allows gas to enter said chamber under conditions of inhalation actuated selected pressure differential across said bypass orifice without significantly varying the selected flow rate;
• and
• e) an actuation switch for causing said drug supply unit to produce said drug vapor.

A device for delivering a drug by inhalation, comprising:

• a) a chamber having upstream and downstream ends;
• b) a drug supply unit that produces drug vapor in communication with a condensation region of said chamber between said upstream and downstream ends;
• c) an upstream orifice communicating with said chamber upstream of said condensation region that allows gas from a user's breath intake to enter said condensation region at a selected flow rate or flow rate range to produce a condensation aerosol of a select particle size range;
• (d) a bypass orifice communicating with said chamber downstream of said upstream orifice at a location that allows gas to enter said chamber under conditions of inhalation actuated selected gas pressure differential across said bypass orifice without significantly varying the selected flow rate;
• and
• d) an actuation switch for causing said drug supply unit to produce drug vapor.