Table 3.
Geometric diameter, aerodynamic diameter, bulk and tapped densities of co-delivery DPI formulations with different initial solid contents in the spray-freeze-drying feed solution (mean ± SD, n=3).
| F | Geometric diameter (μm) | Bulk density (g/cm3) | Tapped density (g/cm3) | Aerodynamic diameter (μm) |
|---|---|---|---|---|
| F1 | 3.4±0.5 | 0.09±0.03 | 0.14±0.02 | 1.4±0.3 |
| F2 | 4.1±0.4 | 0.12±0.02 | 0.19±0.02 | 2.0±0.2 |
| F3 | 10.7±0.4 | 0.23±0.01 | 0.31±0.03 | 6.6±0.9* |
| F4 | 12.6±0.6 | 0.30±0.02 | 0.38±0.02 | 8.5±1.4* |
| F5 | 15.5±1.1 | 0.33±0.03 | 0.41±0.03 | 10.9±1.2* |
| F6 | 17.1±1.5 | 0.51±0.04 | 0.63±0.02 | 14.9±2.7* |
*
represents p<0.05 as compared to F2