Table 1.
Promising technologies in relation to the challenges they take up.
| High Dose Deposition in the Lungs | Reasonable Time of Administration | Prolonged Pulmonary Residence | Potentially Safe Pulmonary Profile | Negligible Environmental Contamination | Ref. | |
|---|---|---|---|---|---|---|
| Dry powder inhalers (DPIs) | ++ | ++ | ~ | ~ | ++ | [28,29] |
| Smart inhalers/targeted deposition | ++ | + | ~ | + | + | [30,31,32] |
| Controlled-release DPI formulations | + | ++ | ++ | + | ++ | [29,33,34,35] |
| Nanomedicine | ~ | ~ | ++ | ++ | ~ | [22,33,34] |
++ highly promising; +, promising; ~subject to optimization (e.g., combination between technologies, future development).