Automated actuation of nasal spray products: effect of hand-related variability on the in vitro performance of Flonase nasal spray.

Objective: To determine if patient-related variability for adults and children recorded during hand spraying of Flonase with an instrumented nasal spray results in significant differences in spray weight, droplet size or spray pattern. Methods: Settings derived from adult and pediatric participants hand-spraying nasal sprays were implemented into force and velocity-controlled automated actuators. Spray weight, droplet size distribution and spray pattern tests were performed using iterations of actuation force (AF) and force rise, hold and fall times. Travel, actuation velocity and release velocity settings were also investigated. Results: The variability measured in adult-derived actuator settings did not result in any differences in spray weight, but pediatric participants spraying with low AF and/or compression velocity (CV) were predicted to receive a partial dose or no dose at all under some circumstances. Droplet size characteristics were sensitive to the hand-based variability, with actuation force, force rise time and CV hand-related settings all resulting in significant differences in the droplet size. Conclusions: This study demonstrated how variability in hand spraying by adults and pediatric patients could result in differences in nasal spray characteristics, thus demonstrating the importance of monitoring how the prospective patient groups are likely to use a nasal spray.