Effective Data Analysis (EDA) and Abbreviated Impaction Method (AIM) concepts have been recommended and advocated by the IPAS-RS Cascade Impaction Working Group as a quality control (QC) tool for inhalation product testing due to its efficiency and effectiveness in distinguishing product performance.
The purpose of this study is to evaluate the feasibility of applying EDA and AIM in the early phase of product development. We retrospectively analyzed the aerodynamic particle size distribution (APSD) results generated using the next generation pharmaceutical impactor (NGI) on a group of suspension metered dose inhalers (MDIs) consisting of different formulation/container closure variants before and after three month storage at 40°C/75%RH using the EDA approach. We assessed the correlation between the mass median aerodynamic diameter (MMAD) and large particle mass (LPM) to small particle mass (SPM) ratio, fine particle dose (FPD) and impactor sized mass (ISM) and their changes after storage.
A good correlation was observed between the MMAD and LPM/SPM at an effective cut off diameter (ECD) of 2.30 μm which is close to MMAD range of 2.5-3.3 μm for this group of product variants. A good correlation was also observed between FPD and ISM as well as their change after storage.
It was concluded from the data analysis that LPM/SPM ratio and ISM can replace MMAD and FPD as an indication for the product performance evaluation therefore an AIM with stages of a properly selected impactor size and ECD can be used for initial product screening.