Development of a dry powder insufflation device with application in in vitro cell-based assays in the context of respiratory delivery

Research on pharmaceutical dry powders has been increasing worldwide, along with increased therapeutic strategies for an application through the pulmonary or the nasal routes. In vitro methodologies and tests that mimic the respiratory environment and the process of inhalation itself are, thus, essential. The literature frequently reports cell-based in vitro assays that involve testing the dry powders in suspension. This experimental setting is not adequate, as both the lung and the nasal cavity are devoid of abundant liquid. However, devices that permit powder insufflation over cells in culture are either scarce or technically complex and expensive, which is not feasible in early stages of research. In this context, this work proposes the development of a device that allows the delivery of dry powders onto cell surfaces, thus simulating inhalation more appropriately. Subsequently, a quartz crystal microbalance (QCM) was used to establish a technique enabling the determination of dry powder deposition profiles. Additionally, the determination of the viability of respiratory cells (A549) after the insufflation of a dry powder using the developed device was performed. In all, a prototype for dry powder insufflation was designed and developed, using 3D printing methods for its production. It allowed the homogenous dispersion of the insufflated powders over a petri dish and a QCM crystal, and a more detailed study on how dry powders disperse over the supports. The device, already protected by a patent, still requires further improvement, especially regarding the method for powder weighing and the efficiency of the insufflation process, which is being addressed. The impact of insufflation of air and of locust bean gum (LBG)-based microparticles revealed absence of cytotoxic effect, as cell viability roughly above 70 % was always determined.

Critical nanomaterial attributes of iron-carbohydrate nanoparticles: Leveraging orthogonal methods to resolve the 3-dimensional structure

Intravenous iron-carbohydrate nanomedicines are widely used to treat iron deficiency and iron deficiency anemia across a wide breadth of patient populations. These colloidal solutions of nanoparticles are complex drugs which inherently makes physicochemical characterization more challenging than small molecule drugs. There have been advancements in physicochemical characterization techniques such as dynamic light scattering and zeta potential measurement, that have provided a better understanding of the physical structure of these drug products in vitro. However, establishment and validation of complementary and orthogonal approaches are necessary to better understand the 3-dimensional physical structure of the iron-carbohydrate complexes, particularly with regard to their physical state in the context of the nanoparticle interaction with biological components such as whole blood (i.e. the nano-bio interface).