Large volume subcutaneous delivery using multi-orifice jet injection.

Needle-free jet injection is an alternative drug delivery technique that uses the liquid drug itself to penetrate through the skin. This technology is not only a promising alternative to hypodermic needles but also has the potential to replace intravenous delivery with rapid, needle-free subcutaneous delivery for large-volume treatments. In this work we propose a parallelised, 'multi-orifice' approach to overcome the volume constraints of subcutaneous tissue. We present a prototype multi-orifice nozzle with up to seven orifices and use this nozzle to perform injections into samples of ex vivo porcine tissue. These injections demonstrated the rapid (<0.15 s) delivery of up to 2 mL into the tissue using both three and seven orifices. Delivery success (measured as the percentage of fluid deposited in the tissue relative to the total volume that left the device) was very similar when using three versus seven injection orifices. A computational fluid dynamic model of multi-orifice jet injection is also presented. This model predicts that jet production is largely unaffected as the spacing between orifices is changed from 3 mm to 48 mm. This finding is supported by measurements of the speed, volume, and shape of the jets produced by the prototype nozzle that showed very similar jets were produced through all seven orifices. These findings demonstrate the feasibility of multi-orifice jet injection for needle-free delivery of large volumes. This promising technique has the potential to improve patient experience and reduce healthcare costs in large volume parenteral delivery applications.