ABSTRACT
Achieving appropriate inhalation in patients with coronavirus disease 2019 (COVID-19) is a common challenge in the use of repurposed metered-dose inhaler (MDI) formulations. The purpose of this study was to evaluate the effect of five valved holding chambers (VHCs) on the inhalation of ciclesonide from Alvesco MDI. The aerodynamic particle size distribution of ciclesonide discharged from Alvesco MDI was evaluated using a Next Generation Impactor in the presence and absence of VHCs. The use of VHCs retained or slightly increased the amount of ciclesonide in the fine particle diameter range (aerodynamic particle size below 3 µm) (FPD) and reduced the amount at the induction port after coordinated inhalation. However, the use of VHC reduced the FPD of the formulation by increasing the time between the MDI discharge and the pump suction by various degrees among the five VHCs. These results indicated that use of the VHCs and minimizing the inhalation delay time should ensure sufficient inhalation of ciclesonide particles.