(522g) Computational Fluid Dynamics Modeling and Experimental Studies of Multi-Port Needles for Optimization of Drug Delivery to Multiple Tissue Layers

While transdermal/subcutaneous injections remain the most efficient way of delivering drugs to the circulatory system to circumvent the barriers typically associated with enteral routes, the immunologic response can be limited due to either (a) poor drug diffusion, or (b) the need for electroporation to enhance cellular uptake.

New developments in drug formulation have presented the industry with successful protein, RNA, and DNA based vaccines; those, however, suffer with poor efficacy in part due to the difficulties of properly delivering these macro-molecules at high concentration, which can result in high-viscosity injectables.

Whilst the hypodermic needle remains the vanguard method of delivery, we sought to improve the delivery with a modified flow regime by placing the outlets along the length of the needle, to create a so-called “sprinkler needle” effect. With the aid of CFD based simulations, we created 3D models of 22 gauge hypodermic needles modified with side-ports along the length of its body. The side-ports varied in geometry, size and number, with the goal of monitoring how those variables affected the outflow distribution; fluid viscosity was also a key variable in our models. Utilizing both simulations and experiments, we were able to study numerous high-viscosity injections and define which set of parameters best benefited from the novel side-port configurations versus regular beveled hypodermic needles.