Application of Modeling as a Tool for Early Derisking of Parenteral Delivery, from the Primary Container to the Tissue

<i>In silico</i> modeling of subcutaneous injections is a promising tool to derisk and optimize the development of injections systems and improve preliminary understanding of the injectability of drugs. Such modeling can be leveraged early in development, prior to pre-clinical studies, to reduce testing burden and effectively predict aspects such as the time and forces required for full dose delivery into tissue and the tissue-injectate-device interactions. In this work, we address the three main <i>in silico</i> pillars (primary container, injection device, and tissue) that are necessary to simulate a parenteral injection. We showcase how their modeling can be combined and applied to various delivery systems and injection conditions to enable appropriate systems and parameters selection to achieve desired performance. Case studies of viscous drugs in PFS/AI and wearable injection systems with non-rigid component properties are presented to highlight the theoretical treatment of interfaces, the critical inputs required to achieve accurate predictions, the insights gained, and the good agreement between model predictions and experimental results.