Design and development of prototype blister-packs for intradermal injection of viscous solutions*

We investigate the feasibility and prototype fabrication of novel blister-pack devices for intradermal and subcutaneous injections. The devices are designed to deliver both low and high-viscosity solutions (potentially nucleic acid vaccines) using hollow micro-needles embedded in a sealed felxible casing, which is pre-filled with a fixed volume.

For this exploratory stage, we used resin-based 3D-printed parts fro both the rigid needle structure and the flexible casing. Our initial results are focused on proof-of-concept, and measurements of the flow rates achievable for various viscosities through the novel needle designs. We show that both water-like (∼1 mPa.s) and more viscous fluids (∼100-200 mPa.s) can flow through these devices. In addition to these initial results, we will demonstrate the capability of delivery into tissues through ex-vivo experiments.