Effect of Compressed Air Pressure on Particle Size Distribution During Aerosol Generation with Ultrafine TiO₂

Maria Malmlöf^1,2, Mattias Nowenwik¹ & Per Gerde^1,2

¹Inhalation Sciences, Hälsovägen 7-9, 141 57, Huddinge, Sweden
²Institute of Environmental Medicine, Karolinska Institutet, Nobels Väg 13, 171 65, Solna, Sweden

Summary

Until now the PreciseInhale aerosol generator has been used to aerosolize micronized APIs by deagglomeration using highly pressurized air (100 bar). The PreciseInhale has now been developed to extend the range of aerosol generation pressures from a low 10 bar up to 160 bar. This broadened pressure range was here used to generate TiO₂ aerosols which was analysed for degree of deagglomeration (SEM imaging) as expressed by the mass median aerodynamic diameter (particle size distribution). It was demonstrated that, in the case of TiO₂ nanoparticles, increased generation pressure resulted in a finer and less agglomerated aerosol. However, depending on the test material, different aerosol properties could be of importance such as maximum deagglomeration or instead intactness of fragile particles. The results demonstrate a potential for individualising the aerosol generation parameters to the material of choice by changing various aerosol generation parameters.