Spraytec – Nasal spray droplet size measurement
Spraytec precisely captures the evolution of nasal spray droplet size through each phase: formation, full developed and dissipation. Measuring over the entire range of interest, in real-time, it offers detailed insight into liquid break-up and dispersion behavior. Powerful data analysis software efficiently draws out key parameters of interest, in line with FDA guidance. Rapid data acquisition accelerates screening and developmental work for device and formulation alike supporting the optimization of:
- Nasal spray device characteristics including orifice diameter and pump mechanism
- Nasal spray formulation properties such as viscosity
- Product performance for a specific patient group
Case Studies
Test set-up: data analysis and automated actuation FDA guidance recommends using data from the fully-developed phase for statistically valid comparative studies. This introductory text looks at the analysis of laser diffraction data for in vitro nasal spray characterization and the benefits of automated pump actuation during measurement. Two commercially available devices were tested and one proved much more sensitive to actuation force than the other. Greater sensitivity suggests more patient dependent operation.
Investigating the importance of formulation viscosity This joint work from Next Breath LLC and Valois SAS uses Spraytec to explore how viscosity enhancing polymers can be used to tailor the droplet size of a nasal spray. Formulation viscosity influences stability and dispersion and consequently in vivo performance. These results demonstrate how rheological information and droplet size measurement combine to support the development of an efficient formulation/device pairing.
Using laser diffraction and image analysis for BA/BE studies For locally acting nasals sprays, test protocols are based on proving equivalence with an existing product whose clinical behavior is known. In this case study Spraytec was used to measure the droplet size of the formulation. A Morphologi G3 automated image analysis system, provided particle size measurement of the active, before and after delivery. In combination these data sets provide detailed evidence for BA/BE studies in line with FDA recommendations.
Investigating tail-off performance The FDA’s CMC guidance recommends analyzing the performance of nasal spray pumps after delivery of labelled dose number, up to the point of product exhaustion. Spraytec was used to measure the reproducibility of delivered droplet size for each actuation of a commercially available nasal spray product, through to container emptying. The results show consistent delivery well past the labelled dose number and provide detailed information as to how performance fails at the end of product life.
Investigating the impact of pump actuation parameters on spray characteristics Automated pump actuation removes the variability associated with manual pump operation during testing. In this collaborative study with Next Breath LLC and Image Therm Engineering Inc, automated actuation parameters – stroke length, hold time, velocity and acceleration - were determined to reflect profiles generated by a group of adult users. The impact of variability in these parameters was assessed through the study of spray plume, geometry and droplet size for formulations of different viscosity. The results have relevance for the setting of test conditions and the development of device/formulations for different patient groups.
