MAY 2021
Inhalation 1-2-3 A brief update from Inhaltion Magazine.

Important factors for choosing DPI formulation technology
imageThere are various particle engineering approaches for developing an inhalable dry powder formulation, including micronizing the drug substance to a respirable particle size or spray drying. The choice between jet milling/micronization and spray drying is dependent upon a number of factors including:
  • API characteristics and ability to be
    jet milled
  • Lactose compatibility
  • Physical properties of the active pharmaceutical ingredients
  • Process and scale-up issues
  • Content uniformity concerns (especially for combination therapies)
  • Particle size distribution requirements
  • Amount of new chemical entity available for feasibility work
Read about technology selection for dry powder inhaler-based product development.

in focus

imageResolving a few misconceptions when analyzing data from inhaler particle size distribution measurements
This article discusses important misconceptions that from-time-to-time have appeared concerning the analysis of particle size data. It primarily focuses on multi-stage cascade impaction, which is the primary technique for OIP APSD measurement. However, attention is also paid to the analysis of size distribution data from time-of-flight analyzers and laser diffractometer instruments that are also encountered in the evaluation of inhaler performance, particularly the latter for the assessment of nasal products. Four misconceptions are discussed: Misconception 1: Impactor-sized mass (ISM) always includes data from all impactor stages; Misconception 2: Geometric standard deviation (GSD) is always suitable as the measure of spread of a size distribution; Misconception 3: The underlying size distribution can be described by a single size-based metric; and Misconception 4. Count/number-weighted size distribution data are a surrogate for volume/mass-based data.

imageNew perspectives on the microstructure of inhalable formulations through laboratory
3-D X-ray microscopy
Unanswered questions relating to pre-aerosolized formulations include (1) What does the blend formulation truly look like? (2) How do different parts of the blend interact with each other? (3) How do we quantify the microstructure? 4) How does the microstructure change due to manufacturing processes or storage? This article explores how X-ray microscopy can offer new insights into the microstructure of inhalable formulations for dry powder inhalers. The findings are part of the INFORM2020 collaboration, a five-year collaboration of academia and industry to investigate critical parameters that influence the performance of dry powder inhaled (DPI) formulations. In part, the collaboration has been attempting to shed light on key questions through X-ray microscopy, which can offer new insights into the microstructure of inhalable formulations for DPIs. The article also includes a brief interview with the authors.

imageInformation on upcoming industry events
Please visit the calendar on Inhalation's website for more conferences, which may change from live to virtual formats and have new dates due to COVID-19.
Questions about Inhalation, contact Vicki Schuman, Editor at
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