When we studied the effect of BAM pressure on dose delivery, we found that increasing BAM pressure, improved dispersion performance, increasing the fraction of particles in in the sub-5 µm range, as shown in the table below. The incorporation of a BAM results in release of the powder into a relatively high air flow rate, so dispersion is a more energetic process, as well as being closely controlled. The results from our investigations suggest that use of a BAM not only enhances the success of aerosolization but improves its consistency, giving more constant drug delivery performance across different inhalation profiles independently from the applied flow rate.
Table 1: FSI dispersion performance from the 4 DPI variants; mean values (n=3)
| No BAM | Low BAM | Control BAM | High BAM | |
| Shot weight (mg) | 9.7 ± 1.0 | 9.2 ± 0.1 | 10.0 ± 0.6 | 9.1 ± 0.3 |
| Metered dose (µg) | 423 ± 11 | 410 ± 4 | 443 ± 10 | 407 ± 33 |
| Fine particle dose <5µm (µg) | 129 ± 2 | 158 ± 9 | 187 ± 9 | 222 ± 18 |
| Fine particle fraction <5µm (%) | 31 ± 1 | 39 ± 2 | 42 ± 2 | 54 ± 2 |
Exerting tighter control over the dispersion process, via technology such as this, would seem to be a sensible direction of travel if we want to push aerosolization performance into new areas, using the same energy input, which is essentially the challenge.
