Issue link: https://www.e-digitaleditions.com/i/1463386
Inhalation April 2022 25 ways that OIPs can be tested have been divided into three separate streams, as summarized in Table 1: a. existing quality control methods in the pharmaco- peial compendia, b. augmented quality control methods aiming to improve clinical realism, c. procedures involving further enhancements to optimize clinical relevance We have broken down each category into the fol- lowing attributes that help define the scope of each approach. ese are as follows: 1. Method capability, or the ability of the technique to achieve the fundamental purpose of provid- ing data that are predictive of the clinical effect resulting from deposition of the medication at the receptor sites in the lungs. 2. Applicability, that relates to the actual and poten- tial purposes of the measurements. 3. Regulatory considerations, subdivided into: (a) current recognition by the major regulatory agencies; (b) compatibility with current product registration requirements; (c) ability to provide additional benefits, such as providing insights into patient use/misuse. 4. Management considerations, subdivided into: (a) compatibility with current product registration practices; (b) cost implications; (c) method trans- ferability; (d) method familiarity. Differentiating three streams for OIP testing A wide selection of options has been researched during the past 15 years that are claimed by their sponsors to improve clinical realism in laboratory-based inhaler testing. e increasing arrival of second-entry prod- ucts as innovator inhalers come off-patent protection is a major stimulus [2]. Here, testing for in vitro bio- equivalence is important and is linked with the desire for improved IVIVCs that has already been men- tioned. Other drivers are a response by those want- ing to understand more clearly the limits to inhaler performance with patients of all ages presenting with differing degrees of chronic lung disease as well as the desire to assess how inhalers perform in situations of misuse [3]. Beyond such improvements in clinical realism, there are those who wish to push the boundaries of mim- icking the process that take place after the medication particles reach the target regions of the lungs. Such developments have involved advanced models that can incorporate cellular tissues as well as surround- ing fluids to simulate the dissolution and absorption processes that take place in both normal and diseased airways [9-12, 33]. Rather than simply separating methodologies into pharmacopeial and clinically relevant groupings, the