A Technical Feasibility of Aqueous Aerosol Generation Based on the Flashing Jet: Impact of Surfactant, Electrolyte, and Drug Concentration

Abstract

This study aimed to investigate the atomization mechanism of a flashing jet (FJ), focusing on the potential factors that influence the atomization performance of the device. Those factors include surfactant, electrolyte, and drug concentration. In this work, Tween 80, sodium chloride (NaCl), and salbutamol sulfate (SBS) were used for the study. The aerosol's mass median aerodynamic diameter (MMAD) was investigated for analysis. The drug delivery ability of the FJ prototype was compared with the Pari nebulizer. Our data suggested that the MMAD of aerosol decreased as the concentration of Tween 80 increased, but the critical micelle concentration point was not influenced. Upon adding NaCl to pure water, with the increase of NaCl concentration, the MMAD of aerosol initially decreased significantly and then increased, reaching the lowest point when 0.05% NaCl was used. A higher concentration of SBS was beneficial for the atomization performance. When the SBS concentration was 5 mg/mL, the MMAD values of the FJ prototype and Pari nebulizer were 2.28 ± 0.15 and 1.03 ± 0.21 μm, respectively, and the fine particle dose (%TDD) of the FJ prototype and Pari nebulizer was 50.99 ± 5.88 and 53.51 ± 4.58%, respectively. Interestingly, the concentration of SBS has no effect on the residual dosage level of the FJ prototype, indicating that it can be applied in atomizing high-concentration solutions. In summary, surfactant, electrolyte, and drug concentration played an important role in the atomization performance of the FJ prototype and these ingredients are also crucial factors that should be considered in future formulation studies.

Keywords

• inhalation drug delivery
• flashing jet
• inhaler prototype