Conclusions - Good Cascade Impactor Practices, AIM and EDA for Orally Inhaled Products - page 403

is equally capable of being applied in the assessment of full-resolution CI data.
Furthermore, EDA metrics have the potential for improved discriminating power in
relation to batch disposition, compared with the current practices either of compar-
ing stage groupings or the determination of FPM < 5.0 mm , used as quality measures in
the USA and Europe, respectively. At the time of writing, both concepts are very
new to stakeholders, so that the pathway to their acceptance will require carefully
crafted validation studies, as outlined in a chapter devoted to the consideration of
how to go about achieving recognition as standard techniques. A chapter has been
devoted to review the development of abbreviated CI-based measurement tech-
niques for OIPs and associated add-on devices. Such methods are becoming more
important in the context of providing APSD data that has been acquired by tech-
niques that more closely mirror the use by patients that can be achieved in the neces-
sarily simplifi ed laboratory techniques associated with quality control. Finally,
prospects for the future developments of AIM and EDA are considered, including
the potential for combining AIM-based size metrics with dose content uniformity
determination in a single apparatus. It is hoped that the content of the topic will
result in the widespread use of these new approaches to the laboratory performance
assessment of OIPs.

14.2 Learning Points

The underlying purpose behind the creation of this topic has been the desire by the
authors to provide both the novice reader and the user familiar with the cascade
impaction method, a “one-stop shop” for technical information that relates to the
current knowledge of the CI for OIP testing. The intention here is to provide a series
of key learning points that it is hoped the reader will have acquired by reading the
topic from cover to cover. However, it is also recognized that the majority of users
will likely dip into only one or more chapters of specifi c interest at any given time,
so the list below serves as an easy access to the key scientifi c material that has been
presented.

Chapter 1 : The AIM and EDA concepts are presented with diagrammatic refer-
ences to generic CI confi gurations; the idea that both concepts can be
used together or independently is also introduced.

Chapter 2 : The underlying theory associated with inertial impaction is explained
in suffi cient detail for the reader to understand the underlying scien-
tifi c basis for the AIM concept and its limitations. This chapter is also
a repository of useful design information relating to the compendial
CI apparatuses. The use of induction ports and pre-separators is
described, as is the adaptation of the CI method using a timed-delay
apparatus following inhaler actuation that is needed to evaluate OIP
add-on devices, such as valved holding chambers.