An investigation of actuation forces and performance of a novel, user-independent nasal spray, based on user-device interaction
S.S. Falloon1 & C. Wolfe1
1 Recipharm, Bergen Way, King’s Lynn, PE30 2JJ, U.K.
Summary
Single dose nasal spray device users fall into a wide demographic, with varying abilities, experience and requirements. These differences, combined with a general need for accurate and reliable drug delivery, highlight the importance of universally appropriate user-device interaction and the benefits of a platform device. The main purpose of the work described in this paper was to assess Recipharm’s proprietary, novel unit dose (NasaDose™) nasal spray device capability with respect to consistent and appropriate actuation forces at two different potential drug formulation viscosities. For this device, all of the delivery force is spring-driven, minimising the effort required, and force experienced, by the end user. As the device has a trigger-based mechanism, the design must ensure conflicting requirements of user ability to actuate and robustness upon drop are met. User actuation capability was assessed by measuring the forces that they could comfortably apply to a model nasal spray, as part of a formative usability study. The data revealed a broad “comfortable actuation” force range of 11.1-52.8 N (mean minimum and maximum for all study participants; relative standard deviation (RSD) 12.3% and 6.8%, respectively). Actuation force and metered shot weight (MSW) were measured after drop tests on two sets of device variants. No actuation of devices occurred when dropped, and there was negligible variation in MSW and slight variation in actuation force after dropping samples. This supports the hypothesis that Recipharm’s proprietary device performs repeatably and reliably, and operates within an identified range of comfortably achievable user actuation forces.