Table 3.

Geometric particle size compared to aerodynamic particle size of spray dried powder formulated with mannitol and dextran (MD) excipient blend in a ratio by weight of either 1:3 or 3:1, using a low molecular weight dextran (40 kDa) or high molecular weight dextran (500 kDa). Aerodynamic particle sizes are presented as MMAD based on experimental measurement using a Next Generation Impactor (NGI). A Helos R-series laser diffraction sensor was used to measure median particle diameter (D50) and span

Formulation Ratio	Dextran MW	Median Particle Diameter, D50 [μm]	Particle Distribution Span [μm]	MMAD [μm]
MD (1:3)	40 kDa	8.7 ± 0.5	4.0 ± 0.3	4.5
MD (1:3)	500 kDa	5.9 ± 0.5	2.4 ± 0.1	4.4
MD (3:1)	40 kDa	4.9 ± 0.7	1.6 ± 0.4	4.5
MD (3:1)	500 kDa	6.1 ± 0.1	2.4 ± 0.2	4.9