Performance Characterization of EDA and Its Potential to Improve Decision Making in Product Batch Release - Good Cascade Impactor Practices, AIM and EDA for Orally Inhaled Products - page 169

grouping (e.g., an increase in mass assigned to one stage grouping could either be due
to mass transfer from one group to another group, because of a shift in APSD, or it
could be due to an increase in both groupings, due to an increase in total mass col-
lected). The magnitude of ratio , which measures the relative proportions of API
assigned to coarse and fine fractions, is not affected by changes in the total amount
collected. Ratio has been shown to be more capable of detecting smaller shifts in APSD
than can be achieved by the current practice of grouped stages (2), and this conceptual
reasoning is exemplified by the quantitative analysis presented in this chapter.

8.2 A “Road Map” for the Comparative Assessment of EDA

Versus Grouped Stages for the Interpretation
of CI-Measured Aerosol APSDs in the Context of OIP
Quality Control

The remainder of this chapter is concerned with testing the power of the EDA
metrics compared with the grouped-stage approach to discriminate changes in
CI-measured OIP APSDs that might be used to come to a decision regarding the
quality of a lot in the context of QC. Figure 8.2 is a “road map” that describes the
different ways in which such data have been assessed. Each of the avenues “A”

Fig. 8.2 “Road map” for APSD assessments: posing the question