Yuqing Ye1,2, Ziyi Fan1, Ying Ma1,2 & Jesse Zhu*1,2
1University of Western Ontario, 1151 Richmond Street, London, N6A 3K7, Canada
2Ningbo Inhale Pharma, 2260 Yongjiang Street, Gaoxin District, Ningbo, 315000, China
Summary
The study on inhaler performance through modified inhalers with homogeneous aperture size across the full grid structure have been carried out. In our research, the size of each small opening except the four in the corners of inhaler grid was kept constant, and the wire splitting the grid was designed to vary, thus generating grids with same aperture size but different voidage (Figure 1). In addition, instead of injection moulding method, a novel 3D printing technology was employed to fabricate the modified inhalers, which is rarely studied. Therefore, the primary objective for this work is to investigate the influence of grid mesh voidage on inhaler performance, as well as confirming the feasibility of 3D-printed inhalers for pulmonary drug delivery. For the assembled 3D-printed inhaler with a voidage of 68.7%, the Fine Particle Fraction (FPF) was raised to 37.2 compared with the inhaler with a voidage of 13.2% and FPF of 33.8%. There was a rising trend of FPF and delivered dose when grid voidage increased, which attributed to less drug impacting on the meshes of grid and more drug passing through the apertures. The experimental results were also coupled with computational fluid dynamics (CFD) analysis, which provided a complementary understanding of the drug delivery performance differences.
Key Message
Modified inhalers by 3D-printing method, with constant aperture size across the full grid structure, were successfully fabricated and assembled. Inhalers with an increased voidage had higher in-vitro drug delivery performance and lower air resistance, which was proved by enhanced powder residues in the devices and more centralized powder jetting verified by CFD.