Aerosol Dynamics of Sodium Chloride at High Relative Humidity
Yiliang Lance Jiang1, Gareth Hardwell2, Richard Friend2 & Jonathan P. Reid1
1University of Bristol, School of Chemistry, Cantock’s Cl, Bristol, BS8 1TS, United Kingdom
2Chiesi Ltd., 1 Bath Road Industrial Estate, Bath Rd, Chippenham, SN14 0AB, United Kingdom
Summary
Inhalers are often prescribed to patients suffering lung or systemic diseases. The size of the particle actuated from the inhalers determines the site of deposition of the therapeutic ingredients. Therefore, an accurate prediction of the drug deposition profile is crucial for maximizing the efficiency of a formulation. Relative humidity (RH) can have a considerable effect on the size distribution of an inhaled medication upon entering the respiratory system. A Tandem Aerodynamic Particle Sizers (TAPS) approach has been developed to measure concurrently the size distribution of the same plume of aerosol at two varied RHs. A Python script was written to fit an optimal size distribution to the experimental data. In this study, sodium chloride have been tested. Comparing the single particle properties, obtained using a comparative kinetics electrodynamic balance (CK-EDB) with plume dynamics show that they are consistent with predictions from a thermodynamic framework. Further study is required to measure particles with different hygroscopicity and mixtures of particles. Factors such as water content and temperature could also be explored either experimentally or using computational models to further optimize the drug deposition profile.