Abstract
BACKGROUND: Compounding and storage of intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents in syringes is commonly performed in an off-label manner. However, the preservation of compound integrity and microbiological safety must be guaranteed. The aim of this study was to compare the chemical and physical stability, sterility and binding affinity to vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) of faricimab, a novel bispecific anti-VEGF/Ang-2 biologic, after compounding and storage in two different polypropylene syringe types for up to 28 days. METHODS: Faricimab was compounded into silicone oil-free and silicone oil-containing polypropylene syringes under controlled aseptic clean room conditions and stored under light protection at 2-8 °C for up to 28 days. Compound integrity was analysed by size exclusion chromatography, nano differential scanning fluorimetry, UV-vis and dynamic light scattering. The analysis of the simultaneous binding of VEGF and Ang-2 was performed by grating-coupled interferometry. Additionally, samples were tested for sterility and presence of bacterial endotoxins. One-way ANOVA test was used to analyse statistical significance (p ≤ 0.05). RESULTS: No significant differences in VEGF and ANG-2 binding affinity were found in faricimab samples stored in either syringe type after 28 days compared to control. Chemical and physical stability testing revealed no statistically significant variation. Furthermore, sterility and the absence of bacterial endotoxins could be maintained. CONCLUSION: Our findings confirm the pharmaceutical safety of compounded faricimab after storage for up to 28 days. This may facilitate a cost-effective off-label use of faricimab in clinical practice while maintaining safety in the treatment of patients.