Maria Patricia Almeida1, Jorge F. Pontes1, Joana Pinto da Silva1, Rui Borges dos Santos1,2, & Ana Grenha1,2
1Centre for Marine Sciences, Universidade do Algarve, Faro, 8005-139, Portugal
2Faculty of Sciences and Technology, Universidade do Algarve, Faro, 8005-139, Portugal
Summary
The in vitro preclinical assessment of inhalable formulations must be performed in conditions mimicking the lung environment. The evaluation of dry powders in this context is challenging because a simple device permitting dry powder aerosolization over surfaces, e.g. cells cultured in well plates, is not readily available. Therefore, the evaluation of dry powders is frequently performed as a suspension, in the case of cell-based studies, the powder being mixed with cell culture medium prior to cell incubation, which does not replicate real respiratory conditions. To mitigate this limitation, our research group has designed and developed a prototype device able to disperse dry powders over surfaces. After several steps of optimization and evolutive versions of the device, a 3D printed device has now been tested using model dry powders (locust bean gum and mannitol) that exhibit different aerodynamic and morphological characteristics. The device´s aerosolization efficiency was evaluated with varied powder dosages (1, 5 and 10 mg), pumped air volumes (20 and 50 mL) and air blow modes. The yield of the aerosolization process was the metric used to quantify the efficiency. The prototype was optimized for compatibility with various cell culture platforms, including 6-well and 12-well plates. The device evidences efficacy in the aerosolization of dry powders, providing reproducible powder dispersion. Efficiencies >40% were obtained, independently of dry powder, pumped air volume and air blow modality. The prototype is a promising tool for in vitro assays involving dry powder aerosolization over surfaces, with potential application in cell-based and release studies.