US Patent 7201164 Aerosol medication delivery apparatus with narrow orifice

An aerosol medication delivery apparatus includes a holding chamber having an input end and an output end and defining an interior space. The output end comprises an orifice having a cross-sectional area of less than about 60 mm2. In one preferred embodiment, the orifice has a circular cross-section. Preferably, the orifice has a diameter of between about 2.0 mm and about 7.50 mm. In one preferred embodiment, an inhalation and exhalation valve is located at the output end. A method of using the holding chamber is also provided.