Background

Backflow in local injection therapy reduces drug delivery efficiency and negatively impacts therapeutic outcomes. Gelatin-based formulations present a promising biomedical approach to enhance injection precision and minimize fluid leakage at the administration site. This study investigates the impact of gelatin particle size and hydrolyzed gelatin concentration on backflow reduction and injection efficiency, aiming to optimize localized drug delivery applications.

Methods

Various gelatin formulations were assessed for particle size (35μm, 75μm) and hydrolyzed gelatin concentrations (5–8%), determining their influence on injection efficiency and backflow reduction. Injection parameters, including volume and needle gauge, were analyzed in versatile tissue models (VTT, VTT-T) and biological tissues (BCM) to evaluate their effects on viscosity and retention.

Results

Experimental findings showed that smaller gelatin particles (35μm) effectively minimized backflow, particularly at higher concentrations (≥5%). Hydrolyzed gelatin displayed viscosity-dependent retention, where optimal concentrations were identified as 30% for lower-molecular-weight HG, 20% for medium-molecular-weight HG, and 8% for higher-molecular-weight HG. Additionally, needle gauge and injection volume played a critical role in backflow rates, emphasizing the need for precise formulation design.

Conclusion

Gelatin-based formulations offer a viable strategy to enhance localized drug delivery, improving injection precision and therapeutic efficacy. Their ability to reduce backflow supports broader applications in biomedical therapies and regenerative medicine. Future research should investigate active drug incorporation mechanisms to further optimize their effectiveness in clinical use.