Delivery of Albuterol Sulphate Soft Mist Aerosols Using a Micro Spray Nozzle Plate Technology Based Pulmospray™

Lei Mao, Nischal Pant, Tashara Ross, Ben Rinne & Donald Ellis

Recipharm Laboratories Inc, 511 Davis Drive, Morrisville, NC, 27560, USA

Summary

The goal of this study is to demonstrate delivery performance and efficiency of an albuterol sulphate solution (2 mg/mL) from a Resyca Pulmospray™ based on a silicon micro spray nozzle plate technology. In the study, delivered dose, aerodynamic and geometric size distribution of the aerosols are measured using dose collector, Next Generation Impactor (NGI) and Spraytec.  The device effectively delivers aerosols of inhalable size with a good delivery efficiency, i.e. more percentage delivery when actuation is synchronized with inhalation to avoid the exhaling phases in the breathing cycles.  This is advantageous for patients dependant on ventilation in a clinical setting.  In addition, impact from the testing flow rate on the aerodynamic and geometric size distribution was investigated.  The results show a decrease in aerosol size when the test flow rate increased.  An equivalent aerodynamic and geometric particle size distribution of 5.554 µm and 5.863 µm were observed when tested at 15 L/min.  This was not observed at 30 L/min where the geometric particle size (3.512 µm) was smaller than the aerodynamic particle size (4.386 µm).  This suggested that physical changes to the droplets, e.g. possible shrinking of the droplets leading to smaller geometric size, might have occurred at the higher test flow rate. This supports industry’s practice of testing nebulizers at a low flow rate of 15 L/min.

Key Message

Pulmospray™ delivers inhalable albuterol sulphate aerosols efficiently by avoiding loss of doses while patients exhale.  The aerosols, although slightly larger than those delivered from typical vibration mesh and jet nebulizers, can still reach the deep lung per in silico deposition model.  The particle size reduced as the testing flow rate increased.  Equivalent aerodynamic and geometric size distribution were observed when tested at 15 L/min.