Temperature controlling device for aerosol drug delivery
A portable air temperature controlling device useful for warming air surrounding an aerosolized drug formulation. Warming the air of an aerosol makes it possible to reduce the diameter of aerosol particles produced by an aerosol generation device. Additionally, warming the air forces the diameter of the aerosol particles to be in the range required for systemic drug delivery independent of ambient conditions. Smaller particles can be more precisely targeted to different areas of the respiratory tract.
1. A method of dissipating power to store heat in a heating element of a temperature controlling device, and then releasing the stored heat to warm air for evaporating a composition containing a pharmaceutically active formulation, said method comprising the steps of:
supplying power from a portable power source to a heating element, said device having a long thermal time constant in still air of greater than about 10 seconds;
storing heat in the heating element as power is supplied from the portable power source; and
flowing air over the heating element to release heat to the flowing air, whereby a thermal constant of said device for releasing heat to the flowing air is less than about 10 seconds.
2. The method of claim 1 , wherein said thermal time constant in still air is greater than about 15 seconds.
3. The method of claim 1 , wherein said thermal time constant in moving air is from about 3.5 seconds to about 5 seconds.
4. The method of claim 1 , wherein said flowing air is driven by inhalation by a user on a channel fluidly connected with the heating element.
5. The method of claim 1 , wherein the portable power source comprises at least one battery and said supplying power comprises flowing electrical current through the heating element.
6. The method of claim 1 , further comprising:
prior to flowing air, allowing the heating element to achieve a predetermined operating temperature.
7. The method of claim 1 , wherein said heating element is an electrically resistive element having a surface area of about 25 to about 60 cm 2 .
8. The method of claim 1 , wherein said heating element is corrugated to form gaps to channel air therethrough.
9. The method of claim 1 , wherein said heating element is constructed of two banks and each said bank is configured into a series of narrow channels.
10. The method of claim 1 , wherein said heating element has a mass of about 0.1 to 4.0 grams and a surface area of about 30 to about 55 cm 2 .
11. The method of claim 10 , wherein said element has a mass of about 0.2 to about 2.0 grams and a surface area of about 35 to about 45 cm 2 .
12. The method of claim 11 , wherein said element has a mass of about 1.25 grams and a surface area of about 39 cm 2 .
13. The method of claim 1 , wherein said temperature controlling device is hand-held.