This study was aimed to measure actuation force for unit dose liquid nasal sprays (UDS) filled with water using various analytical methods and to evaluate method’s limitations, suitability and robustness. General pieces of equipment specifically designed for force measurement such as electromechanical universal test systems are capable of accurately determining the actuation force although some limitations exist to achieve the actual actuation velocities applied by the patients during the actuation of the device. The objective of the study was to evaluate differences between the three systems used for force measurement including MTS Criterion® Electromechanical Universal Test System, Proveris SprayVIEW NSx Actuation Station and Innova NSP Universal Actuator. The differences in actuation force are described and compared between three analytical methods.
In this study, the Proveris SprayVIEW NSx Actuation Station and Innova NSP Universal Actuator were more suitable for actuation force comparison studies because they can achieve a higher actuation velocity (similar to that of a human hand) compared to the MTS Criterion® Electromechanical Universal Test System which is more suitable for measuring actuation forces associated with the breakage of the ring and of the piercing of the plunger.