DDU tester

for aqueous droplet inhalers

Both MDIs and DPIs suffer from the same two inherent problems: low lung deposits (typically 5-20%) and dose variability (often due to patient difficulties in coordination or inspiration). Aqueous Droplet Inhalers (often known as “Solution Metering” or “Soft Mist” Inhalers), are a new generation of inhaler designed to overcome these problems. Since they are active, aqueous-based devices, the DDU testing of ADIs is similar to that of MDIs, with testing carried out at a constant flow rate of 28.3 L/min.