Depending on the underlying respiratory disease or patient population, medical aerosol should provide characteristics to support drug targeting. For example, infants require very small droplets combined with a high Respirable Fraction (RF) and Aerosol Output Rate (AOR) in a short nebulisation time for a successful nebuliser therapy. Today, doctors can choose from a vast range of jet nebulisers with only limited information on objective comparison data. Thus, aerosol performance of commercial nebuliser systems was tested on a standardised basis - the current European standard EN ISO 27427 - and used the Respirable Drug Delivery Rate (RDDR) for an objective evaluation.

15 jet nebuliser systems were measured. Aerosol Output and AOR were determined with a breathing simulator. The Mass Median Aerodynamic Diameter and RF were measured with a cascade impactor. But these parameters are of limited clinical relevance. Thus, the RDDR was calculated as the product of AOR and RF from the EN ISO 27427 data.

A high variability in the measured parameters was observed. PARI BOY Classic/Pro and PARI BOY Junior had with 160 µl/min the highest AOR, which was over 3-fold higher than that of Aponorm Compact Plus and BRM-085II. The RF ranged from 80% for the PARI BOY Pro/Junior to 56% for the Atomisor Aerodjinn+28NL9MU. The RDDR data varied by a factor of 3. The PARI BOY Junior (115 µl/min) showed significantly the highest and the Aponorm Compact Plus (36 µl/min) the lowest RDDR.

The RDDR can guide doctors in the selection of an efficient nebuliser system. From a device with a high RDDR it can be deducted that patients receive high inhalable doses in a short time, thus achieving the best possible therapeutic effect.