Exploring how the application of patient-representative inhalation profiles can improve the relevance of test data.
This article reviews the capabilities of breathing simulators and their application in nebulizer, dry powder inhaler (DPI) and pMDI testing, clearly differentiating between that which is specified by the pharmacopeias and that which remains optional but potentially valuable. The focus is delivered dose uniformity (DDU) testing and aerodynamic particle size distribution (APSD) measurement. Delivered dose and APSD are considered Critical Quality Attributes (CQAs) for OIPs, variables that define clinical efficacy and consequently drive the majority of in vitro testing.