Evidence of the Utility of Needle-Free Injectable Devices for Subcutaneous Administration of Biopharmaceuticals: Comparable Study of in vivo Pharmacological and Vaccination Ability to Normal Injection.

Background: Needle-free injectable (NFI) technology has attracted increasing attention as a promising alternative to conventional needle-based injections. NFI devices offer several advantages, including reduced pain, minimized medical waste, and the elimination of needlestick injury risks. However, quantitative evidence comparing their pharmacological performance with that of standard subcutaneous (SC) injections remains limited, particularly for different biopharmaceuticals. Methods: We compared a novel NFI device (SAIJECT Results: There was no significant difference in the pharmacological activities of insulin and OVA delivered via the NFI-device and those via standard SC injection, suggesting that the NFI device was comparable to normal injection. Evans blue dye injected by the NFI device was broadly distributed throughout the dermis and subcutaneous tissue without skin perforation, leakage, or localized accumulation. These results indicate that NFI device can deliver drugs efficiently into the subcutaneous tissue while maintaining tissue integrity. Moreover, this NFI device exhibited negligible drug adsorption, indicating favorable physicochemical compatibility. Conclusion: These findings provide direct evidence supporting the applicability of NFI technology for the SC delivery of biopharmaceuticals and highlight the potential of the NFI devices as a practical and effective alternative to conventional needle-based injection methods. In addition, this comprehensive evaluation of NFI devices provides fundamental insights for the translational application of NFI devices as a practical alternative to needle-based injections.