Inhalation device for producing a drug aerosol

• US 20040099266A1
• Filed: 05/20/2003
• Published: 05/27/2004
• Est. Priority Date: 11/27/2002
• Status: Active Grant

• Current Assignee: Alexza Pharmaceuticals Inc. (Grupo Ferrer Internacional SA)
• Original Assignee: Alexza Pharmaceuticals Inc. (Grupo Ferrer Internacional SA)
• Inventors: Tom, Curtis, Hale, Ron L., Lloyd, Peter M., Hodges, Craig C., Quintana, Reynaldo J., Cross, Stephen, Rabinowitz, Joshua D., Myers, Daniel J., Wensley, Martin J.
• Granted Patent: US 7,913,688 B2
• Time in Patent Office: Days
• US Class Current: 128/203.12
• CPC Class Codes: A61M 11/002 by flow deviation causing inertial separation of transported particles
• CPC Class Codes: A61M 11/041 using heaters
• CPC Class Codes: A61M 11/042 electrical
• CPC Class Codes: A61M 11/047 by exothermic chemical reaction
• CPC Class Codes: A61M 15/00 Inhalators drug delivery in endotracheal tubes A61M16/04

Abstract

A device for delivering a drug by inhalation is disclosed. The device includes a body defining an interior flow-through chamber having upstream and downstream chamber openings, and a drug supply unit contained within the chamber for producing, upon actuation, a heated drug vapor in a condensation region of the chamber. Gas drawn through the chamber region at a selected gas-flow rate is effective to form drug condensation particles from the drug vapor having a selected MMAD between 0.02 and 0.1 MMAD or between 1 and 3.5 μm. A gas-flow control valve disposed upstream of the unit functions to limit gas-flow rate through the condensation region to the selected gas-flow rate. An actuation switch in the device activates the drug-supply unit, such that the drug-supply unit can be controlled to produce vapor when the gas-flow rate through the chamber is at the selected flow rate.

Claims

1. A device for delivering a drug by inhalation or nasally, comprising

a) a body defining an interior flow-through chamber having upstream and downstream chamber openings,

b) a drug supply unit contained within said chamber for producing, upon actuation, a heated drug vapor in a condensation region of the chamber adjacent the substrate and between the upstream and downstream chamber openings,

wherein gas flowed through said chamber region at a selected gas-flow rate is effective to condense drug vapor produced by said unit to form drug condensation particles having a selected MMAD particle size,

c) a gas-flow control valve disposed upstream of said unit for limiting gas-flow rate through said condensation region to said selected gas-flow rate, as gas is flowed through said chamber, and

d) an actuation switch for actuating said unit, such that said unit produces vapor with the gas-flow rate through said chamber controlled to said selected flow rate.

2. The device of claim 1, for use in delivering a drug by inhalation, wherein said chamber is designed for substantially laminar air flow within said chamber the selected air-flow rate is in the range of 4-50 L/min and the condensation particles produced by condensation of drug vapor are in the range 1-3.5 μ

m MMAD.

3. The device of claim 1, for use in delivering a drug by inhalation, wherein the gas-flow control valve is designed to produce a selected gas-flow rate effective to produce aerosol particles in the 20-100 nm size range.

4. The device of claim 1, wherein said gas-flow valve is designed to limit the rate of air flow through said chamber, as the user draws air through the chamber by mouth.

5. The device of claim 4, wherein the gas-flow valve includes an inlet port communicating with said chamber, and a deformable flap adapted to divert air flow away from said port increasingly, with increasing pressure drop across the valve.

6. The device of claim 4, wherein said gas-flow valve includes said actuation switch, with valve movement in response to an air pressure differential across the valve acting to close said switch.

7. The device of claim 4, wherein said gas-flow valve includes an orifice designed to limit airflow rate into said chamber.

8. The device of claim 4, which further includes a bypass valve communicating with the chamber downstream of said unit for offsetting the decrease in airflow produced by said gas-flow control valve, as the user draws air into said chamber.

9. The device of claim 1, wherein the actuation switch includes a thermistor that is responsive to heat-dissipative effects of air flow through the chamber to activate said drug-supply unit.

10. The device of claim 9, which further includes a user-activated switch whose actuation is effective to heat said thermistor, prior to actuation by the thermistor of the drug-supply unit.

11. The device of claim 1, wherein said actuation switch is effective to activate said drug-supply unit prior to the selected gas-flow rate being reached, such that vapor is produced by said unit in said chamber when said selected gas-flow rate is reached.

12. The device of claim 1, wherein said actuation switch is effective to activate said drug-supply unit when the selected gas-flow rate is reached.

13. The device of claim 1, wherein said drug-supply unit includes

i. a heat-conductive substrate having an outer surface,

ii. a film of drug formed on said substrate surface, and

iii. a heat source for heating the substrate to a temperature effective to aid drug,

14. The device of claim 13 wherein said drug delivery unit is effective to vaporize the film of drug, following actuation, within a period of less than 1 second.

15. The device of claim 14, wherein said drug delivery unit is effective to vaporize the film of drug, following actuation, within a period of less than 0.5 second.