Influence of inhalation flow rate on the particle size of liposomal carrier aerosol generated by the medical nebulizer

Abstract

Nebulizers are medical devices for inhalation treatment that create an aerosol from liquid drug formulation. The efficacy of the treatment is dependent on the particle size distribution (PSD) of generated aerosol. PSD can be influenced by the inhalation flow rate as well. Within the here-presented study PSD of aerosol generated by nebulizer Pari LC Sprint Star was measured by Phase Doppler Anemometry for inhalation flowrate of 8; 12; 20 and 40 l/min. The nebulized solution consisted of a liposomal system (20 %) from dipalmitoylfosfatidylcholine (DPPC), phosphatidic acid (PA) and cholesterol (Chol), and MiliQ – ultrapure water (80 %). Slight dependence of PSD on inhalation flow rate was identified. With the increasing flow rate, the particle size of generated aerosol is decreasing. However, the change of Dv50 with the measured flow rates was smaller than 1 µm. According to the results, the change in particle size induced by flow rate will not have a significant impact on drug delivery.