Good Cascade Impactor Practices - Good Cascade Impactor Practices, AIM and EDA for Orally Inhaled Products - page 99

Inhaler
Mouthpiece

Induction
port

Full
Resolution
CI

Entrance Cone

Sample
Collection

Sample
Preparation

API Assay

Fig. 4.5 Potential steps involved in API recovery and assay with eight-stage full-resolution CI
including backup filter

those needed if the number of stages is reduced to one plus the backup filter in an
abbreviated impactor (Fig. 4.6 ). However, even with method simplification, the
principles of GCIP, which have been outlined earlier in this chapter, are equally
applicable to ensure the most accurate and reproducible measurements.
Much of the remainder of this handbook is concerned with the development and
validation of concepts based on the AIM concept, augmented by the adoption of
new ways of working more effectively with the data that are produced by both
abbreviated and full-resolution CI systems (EDA).

4.4 Good CI Data Analysis Practices

Although not covered by the GCIP article, the development of good CI data analysis
principles for APSD assessments was later summarized by Mitchell and Dunbar
[ 78 ] and later augmented by Christopher et al . [ 79 ]. These concepts are described
below in order to complete the process of defining practices that are likely to opti-
mize the overall CI methodology for OIP assessments.

4.4.1 Representation of CI Data

The mass of API recovered from each component of the CI system, from the induc-
tion port to the backup filter constitutes the raw data that are obtained by the cascade