Verification of the EDA Concept Through an Assessment of Theoretical Failure Modes, Failure Mode Analysis, and Case Studies with Real Data - Good Cascade Impactor Practices, AIM and EDA for Orally Inhaled Products - page 268

Table 9.5 Comparison between EDA and stage groupings approach to the assessment of
CI-measured data fro m a solution-formulated MDI ( from [ 9 ] —used by permission )

Correlation ( R 2 values) between mass deposition by stage grouping, MMAD
and LPM/SPM
MMAD ( d 50 ( μ m) μ m) Group 2 Group 3 Group 4

0.83 0.98 0.7814 0.0655 0.7023

1.36 0.92 0.8488 0.0348 0.6057

2.30 0.84 0.8623 0.0155 0.5418

3.99 0.86 0.9027 0.0110 0.5454

Fig. 9.17 OIP product “A”APSD changes in 24-month stability trial assessed by CI stage
groupings

EDA was also able to detect the trend as a time-dependent increase in LPM/SPM
(Fig. 9.19 ). However, the corresponding decrease in ISM pointing to a change in
mass entering the CI from the OIP would not have been as obvious if viewed either
from variations in individual stage groupings or FPM .
In the case of product B, stability trending was observed with all three groupings
(Fig. 9.20 ); the shift to larger values for stage 2 is accompanied by decreases in both
groups 3 and 4 pointing to an overall APSD movement towards larger sized particles.
This shift in APSD was also detected by a trend towards decreased values of
FPM with time (Fig. 9.21 ).