MAY 2023
Inhalation 1-2-3 A brief update from Inhaltion Magazine.

Establishing a robust environment for inhaler testing
imageThe dynamic nature of inhaled drug delivery products makes testing susceptible to variability. Sub-optimal environmental control is one of many variables that could have significant practical and economic implications for inhaler test data.

Studies have shown that inadequate control of environmental temperature, relative humidity and/or electrostatic charge can affect inhaler testing measures such as particle size (including mass median aerodynamic diameter (MMAD) and fine particle fraction (FPF)) and particle deposition. Strategies to minimize environmental variability have the potential to improve inhaler test data integrity and therefore reduce the risk of costly testing delays.

Individual climate-controlled chambers such as EnviroMate™ simultaneously control temperature, relative humidity and electrostatics, offering a cost-efficient solution for mitigating the impact of variable environmental conditions within the laboratory, as well as enabling the tight replication of conditions across different laboratories, sites and countries.

Copley Scientific
UK: +44 1159 616229
in focus

imageSpray drying to enable new inhaled drug products
Spray drying is used to produce engineered, inhalable dry powders and is a critical tool for new drug developers. It enables production of powders with a tightly controlled range of particle sizes and solid-state properties. Formulators have control over the crystalline and amorphous character and radial distribution of components and particle morphology. This comes from understanding the impact of each material's physicochemical properties and the kinetics of droplet drying.

Many key process inputs and variables must be considered when designing an inhaled formulation and the associated spray-drying process. Atomization, solution composition, solvent and excipient selection, and particle collection are some factors that have the largest influence on material properties. Since the particle size of the drug product is critical for inhaled therapies, optimizing these variables to manufacture particles of the targeted size, with appropriate aerodynamic properties, is a primary objective of respiratory programs. This article discusses these considerations expands them into current applications.

imageExploring the robustness of the pharmacopeial methods for testing dry powder inhalers (DPIs); Part 1: Delivered dose uniformity (DDU)
Much improvement has taken place in evaluating sources of variability in the measures of delivered dose uniformity (DDU) and aerodynamic particle size distribution (APSD). Methods described in the United States Pharmacopeia (USP) and European Pharmacopoeia (Pharm. Eur.) now include dimensions and diagrams for all components critical to their robustness. However, the authors show that there are sources of bias in the standard methods for DDU. A future article will address APSD.

Control of the volumetric flow rate into sampling apparatuses for the performance testing of all types of passive dry powder inhalers (DPIs) is critical, as this measure influences the kinetics associated with mass transfer of the active pharmaceutical ingredient(s) (API(s)) from the inhaler to the measurement apparatus. However, and perhaps surprisingly, volumetric flow rate is a dependent variable in the standard pharmacopeial protocols. Given this situation, it is incumbent for stakeholders to be aware of sources of potential bias to have complete confidence in this important inhaler performance measure.

Please visit Inhalation's website to see contact information for multiple industry organizations, many of which present conferences, workshops and other educational events:
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