Influence of Fluid Physiochemical Properties on Aerosolization Performance of a Novel Soft Mist Inhaler

Influence of Fluid Physiochemical Properties on Aerosolization Performance of a Novel Soft Mist Inhaler  

Varsha Komalla¹, Imco Sibum³, Bernhard Muellinger³, Wietze Nijdam⁴, Vishal Chaugule⁵, Julio Soria⁵, Nicolas A. Buchmann³, Hui Xin Ong^1,2, and D. Traini^1,2  

¹Respiratory Technology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia

 ²Macquarie Medical School, Department of Biological Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW 2109, Australia

³Resyca B.V., Enschede, the Netherlands

⁴Medspray B.V., Enschede, the Netherlands

⁵Laboratory for Turbulence Research in Aerospace and Combustion (LTRAC), Department of Mechanical and Aerospace Engineering, Monash University, Clayton Campus, Melbourne, VIC 3800, Australia

Summary

The purpose of this work is to provide a better understanding of the effects of different levels of excipients affecting fluid properties and inhalation flow rates on the aerosol performance of the novel Soft Mist Inhaler (SMI), Pulmospray^TM. Water for injection (WFI) was used as a solvent and the excipients included were varying concentrations of ethanol (5 to 50% v/v), glycerol (5 to 30% w/v), sodium chloride (0.3 to 9% w/v) and span 20 (0.01 and 0.05% v/v). The excipients were evaluated to elucidate the impact of these additions to the solution formulation properties on inhalation aerosol variables (Particle Size Distribution, PSD, Dv10, Dv50 and Dv90) at two different flow rates (15 and 30 L/min). In general, an increase in the concentration of any excipients added increased osmolality. The addition of Span 20 and ethanol individually to WFI resulted in a decrease in surface tension, and the addition of glycerol increased viscosity. In summary, the characteristic of aerosol generation and the performance of the SMI did not change significantly over the range of tested surface tension (75 – 28mN/m), viscosity (1 – 2.4mPas) and osmolality, thus showing the robust aerosol delivery of the SMI over a relevant range of rheological properties used in inhalation solutions.