Validating AIM-Based Instrumentation and Associated Measurement Techniques - Good Cascade Impactor Practices, AIM and EDA for Orally Inhaled Products - page 330

Fig. 10.58 Comparisons of FPF <5.0μm reported by Sheng and Watanabe from a pMDI-produced
aerosol measured by FSI, NGI, and ACI at different flow rates; error bars represent ±1 SD. ( a )
30 L/min. ( b ) 45 L/min. ( c ) 65 L/min ( From [ 53 ]— courtesy of G. Sheng )

Table 10.16 Nebulizer formulations tested in the study of Sheng and Watanabe; “+” high,
“0” medium, “−” low value relative to series average ( From [ 53 ]— courtesy of G. Sheng )

Particle morphology
based on aspect
ratio (−, +)

Size of
particles in
formulation

Formulation
code

Surfactant type (0, I, II)/
concentration (+, −)

API concentration
(−, 0, +)

A − I/+ + Submicron

B − I/+ + Submicron

C − I/− and II/− − Submicron

D − I/0 and II/− 0 Submicron

E − I/+ + Submicron

F + I/+ + Micron

G − I/+ + Micron

H − I/+ + Micron

I + I/+ + Micron

surfactant (Table 10.16 ). Their results (Fig. 10.59 ), obtained at higher flow rates
than recommended (15 L/min) for evaluating this class of inhaler (28-30 L/min),
nevertheless demonstrated an excellent correlation ( r 2 ~ 0.97) between these abbre-
viated and full-resolution apparatuses.
Sheng and Watanabe also extended their comparison of the FSI to the evaluation
of a vibrating membrane nebulizer (Aeroneb ® Go, Aerogen Ltd., Galway, Ireland)