DEVICE AND METHOD FOR CREATING AEROSOLS FOR DRUG DELIVERY
A drug delivery device and method is disclosed which produces aerosolized particles of pharmaceutically active drug for delivery to a patient by inhalation. The device is comprised of a liquid feeding source such as a channel to which formulation is added at one end and expelled through an exit opening. The feeding channel is surrounded by a pressurized chamber into which gas is fed and out of which gas is expelled from an opening. The opening from which the gas is expelled is positioned directly in front of the flow path of liquid expelled from the feeding channel. Various parameters are adjusted so that pressurized gas surrounds liquid flowing out of the feeding channel in a manner so as to maintain a stable capillary microjet of liquid until the liquid exits the pressure chamber opening and is aerosolized. The aerosolized particles having a uniform diameter in the range of about 1 to 5 microns are inhaled into a patient's lungs and thereafter reach the patient's circulatory system.
1 .- 20 . (canceled)
21 . A method of substantially eliminating the clogging of an exit orifice in a drug delivery nozzle, comprising the steps of:
feeding a pharmaceutically active liquid drug through a feeding source in a manner which causes the drug to be expelled from an exit opening of the feeding source in a liquid stream;
forcing a gas through a pressure chamber which surrounds the exit opening of the feeding source, whereby the gas is fed in a manner which causes the gas and the drug to exit the pressure chamber from an exit orifice of the pressure chamber, the gas and drug exiting downstream of a flow path of the drug expelled from the exit opening of the feeding source;
wherein the exit opening of the feeding source is separated by a distance of from about 0.002 mm to about 2 mm from the exit orifice of the pressure chamber;
wherein the liquid drug is kept out of contact with any surface of the exit opening of the pressure chamber by the gas from the pressure chamber surrounding the liquid stream.
22 . The method of claim 21 , carried out using the feeding source, pressure chamber, and drug of a hand-held, self-contained portable drug delivery device
23 . The method of claim 21 , further comprising:
allowing the liquid stream to exit the pressure chamber and disassociate into particles having an aerodynamic diameter in a range of from 0.1 micron to about 10 microns.
24 . The method of claim 23 , wherein liquid stream disassociates into particles having an aerodynamic diameter in a range of from 1 to 5 microns.
25 . The method of claim 21 , wherein the exit opening of the feeding source has a diameter in a range of about 0.002 mm to about 2 mm.
26 . The method of claim 25 , wherein the exit orifice of the pressure chamber has a diameter in a range of about 0.002 mm to about 2 mm.
27 . The method of claim 24 , wherein the pharmaceutically active liquid drug is a solution.
28 . The method of claim 24 , wherein the pharmaceutically active liquid drug is a suspension.
29 . The method of claim 21 , wherein the liquid drug has a viscosity in a range of from about 10 −4 to about 1 kg/m/sec.
30 . The method of claim 24 , wherein the gas is air.
31 . The method of claim 22 , wherein the gas is CO 2 .
32 . The method of claim 25 , wherein the exit opening of the pressure chamber has a diameter in the range of from about 0.01 mm to about 0.4 mm.
33 . The method of claim 22 , wherein the drug fed through the feeding source has a volume in the range of 5 microliters to 10,000 microliters.
34 . The method of claim 21 , wherein gas is forced into an area around the feeding source outlet at a pressure above 10 mBar above atmospheric pressure.
35 . The method of claim 34 , wherein gas is forced into an area around the feeding source outlet at a pressure below 50,000 mBar above atmospheric pressure.
36 . A hand-held self-contained portable drug delivery device during operation, comprising:
a feeding source having therein a liquid drug which flows through the feeding source and is expelled from an exit opening of the feeding source in a liquid stream;
a pressure chamber containing a pressurized gas, said pressure chamber comprising an exit orifice configured such that the gas and liquid stream exit downstream of a flow path of the drug expelled from the exit opening of the feeding source;
wherein the exit opening of the feeding source is separated by a distance of from about 0.002 mm to about 2 mm from the exit orifice of the pressure chamber;
wherein during operation of the device the liquid stream is maintained out of contact with any surface of the exit opening by gas surrounding the liquid stream;
wherein clogging of the nozzle is substantially eliminated;
wherein the device does not require cleaning of the nozzle; and
further wherein the device does not require replacement of the nozzle.
37 . The device of claim 36 , wherein during operation of the device the drug and gas exiting the pressure chamber comprises particles having an aerodynamic diameter in a range of from 0.1 micron to about 10 microns.
38 . The device of claim 37 , wherein during operation of the device the drug and gas exiting the pressure chamber comprises particles having an aerodynamic diameter in a range of from 1 to 5 microns.
39 . The device of claim 37 , wherein the pharmaceutically active drug is a solution.
40 . The device of claim 37 , wherein the pharmaceutically active drug is a suspension.
41 . The device of claim 38 , wherein the gas is CO 2 .
42 . The device of claim 41 , wherein the exit opening has a diameter in the range of from about 0.01 mm to about 0.4 mm.
43 . The device of claim 38 , wherein during operation of the device the drug fed through the feeding source has a volume in the range of 5 microliters to 10,000 microliters.
44 . The device of claim 38 , wherein during operation of the device gas is forced into an area around the feeding source outlet at a pressure above 10 mBar above atmospheric pressure.
45 . The device of claim 44 , wherein during operation of the device gas is forced into an area around the feeding source outlet at a pressure below 50,000 mBar above atmospheric pressure.