Figure 2

Particle/liter counts (0.3–1.0 μm through > 5 μm) after a single actuation of BDP-HFA pMDI in ambient air (left) and ETS (right). Particle count was measured with a sampling time of one second. Continuous red lines indicate mean particle count of the background and after BDP-HFA pMDI shot. The sign "delta" shows the gradient in particle count after drug delivery(means of 100 counts after delivery less means of 100 counts before delivery). When delivered in ETS, a net decrease in the number of 0.3–1.0 μm particles occurred as compared to delivery in ambient air, while a concurrent increase in the number of larger particles was observed.