At the recent Drug Delivery to the Lungs Conference, DDL 17, held in Edinburgh, Scotland, Paul Kippax, product manager for diffraction systems at Malvern Instruments, presented the results of collaborative work on the aerosolization of powders for inhalation.
This work involved the use of the Malvern Spraytec particle size analyzer to examine the time dependence of powder release from a dry powder inhaler (DPI). It was carried out in collaboration with Dr. David Morton, a recognized expert in the development of inhalation systems.
The interactions between a drug-containing powder formulation and an inhaler device are notoriously complex and traditional techniques for their study have recognized limitations. With the Spraytec system, the time-dependence of the dose delivered can be measured rapidly for different formulations, providing reliable information for product optimization. In addition, the impact of various inhaler device characteristics can be assessed.
One conclusion from the work was that the Spraytec system provided improved insight into the mechanisms governing powder plume evolution. It made possible the study of how the concentration of the plume changed over time during actuation, enabling a clearer understanding of the factors influencing the process of powder entrainment and dispersion. It is expected that use of the Spraytec will accelerate product development and also the generation of successful formulations targeting specific areas of the respiratory system.
The Spraytec features an inhalation cell that is designed specifically for drug delivery applications. It enables measurements to be carried out under fixed or varying flow conditions. A data acquisition rate of 10 kHz coupled with a wide dynamic range allows the delivery profiles of both fine drug particles and coarser excipients to be captured simultaneously in exceptional detail. Understanding the interactions between different components of a formulation is crucial to developing a product with the required dispersion characteristics.