Table 4.
Comparison of HFA 227 formulations with different concentrations of ethanol (data represent mean ± SD, n = 3).
| Ethanol concentration (% w/w)/(vapor pressure, psi) | ||||
|---|---|---|---|---|
| 5 (59.8 psi) | 10 (54.6 psi) | 13 (52.8 psi) | 15 (50.2 psi) | |
| ED (μg) | 195.08 ± 23.25 | 194.26 ± 14.19 | 193.31 ± 12.44 | 209.52 ± 11.02 |
| FPF (%) | 54.31 ± 5.65 | 45.39 ± 2.90 | 35.02 ± 2.26** | 29.27 ± 0.77* |
| FPD (μg) | 105.07 ± 2.31± | 87.91 ± 1.73± | 67.52 ± 0.38± | 61.28 ± 1.79± |
| MMAD (μm) | 5.13 ± 0.23 | 5.05 ± 0.15 | 5.55 ± 0.18 | 5.79 ± 0.05* |
| GSD | 1.74 ± 0.12 | 2.07 ± 0.01 | 1.73 ± 0.03 | 1.78 ± 0.01 |
| VMD (μm) | 5.32 ± 0.54 | 8.03 ± 0.36 | 9.72 ± 0.56 | 12.0 ± 0.44* |
ED: emitted dose, MMAD: mass median aerodynamic diameter, FPF: fine particle fraction, FPD: fine particle dose, and GSD: geometric standard deviation. *P < 0.05 (ANOVA/Tukey's) 15% w/w EtOH versus 10 and 5% w/w EtOH, **P < 0.05 (ANOVA/Tukey's) 13% w/w EtOH versus 10 and 5% w/w EtOH, and ± P < 0.05 comparing all formulations (ANOVA/Tukey's).