Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6481859 | International Journal of Pharmaceutics | 2016 | 8 Pages |
The present study investigates the effect of DPI resistance and inhalation flow rates on the lung deposition of orally inhaled mannitol dry powder. Mannitol powder radiolabeled with 99mTc-DTPA was inhaled from an Osmohaler⢠by healthy human volunteers at 50-70 L/min peak inhalation flow rate (PIFR) using both a low and high resistance Osmohalerâ¢, and 110-130 L/min PIFR using the low resistance Osmohaler⢠(n = 9). At 50-70 L/min PIFR, the resistance of the Osmohaler⢠did not significantly affect the total and peripheral lung deposition of inhaled mannitol [for low resistance Osmohalerâ¢, 20% total lung deposition (TLD), 0.3 penetration index (PI); for high resistance Osmohalerâ¢, 17% TLD, 0.23 PI]. Increasing the PIFR 50-70 L/min to 110-130 L/min (low resistance Osmohalerâ¢) significantly reduced the total lung deposition (10% TLD) and the peripheral lung deposition (PI 0.21). The total lung deposition showed dependency on the in vitro FPF (R2 = 1.0). On the other hand, the PI had a stronger association with the MMAD (R2 = 1.0) than the FPF (R2 = 0.7). In conclusion the resistance of Osmohaler⢠did not significantly affect the total and regional lung deposition at 50-70 L/min PIFR. Instead, the total and regional lung depositions are dependent on the particle size of the aerosol and inhalation flow rate, the latter itself affecting the particle size distribution.
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