Reaching new heights? Maximum subcutaneous injection volumes from a technical and clinical development strategy perspective.

This manuscript reviews the evolving landscape of subcutaneous (SC) drug delivery, highlighting the increasing acceptance of administering higher volumes of biological products into SC tissue via injection or short-term infusion. Traditionally, fast bolus injection volumes for SC injection were considered very limited with 1 or a maximum of 2 mL. Nowadays, SC administration volumes of well above 2 mL, and up to 10 and even 25 mL are increasingly pursued for product development, undergoing clinical trial investigation, or are already commercialized. This article explores how the choice of SC injection volume in relation to formulation strategy and combination with injection devices for a biological product can impact both the technical and clinical drug product development strategy across different phases during the lifecycle of a product. The article specifically addresses the current technological challenges and limitations associated with developing high-volume drug products for SC administration. Finally, the review outlines most recent trends in technical drug product and clinical development programs, offering insight into future directions for SC drug delivery especially towards increasing SC administration volumes.