Long-term in vitro functional stability of compounded ranibizumab and aflibercept

To determine the long-term in vitro functional stability of compounded ranibizumab and aflibercept.

Laboratory study.

Ranibizumab and aflibercept were compounded into plastic syringes and stored under refrigerated conditions for up to 4 weeks. Half maximal inhibitory concentrations (IC₅₀) from dose-response curves generated by using drugs and their respective targets in enzyme-linked immunosorbent assays were calculated. The functional activity of the drugs stored under these conditions was then compared with that of drug from a fresh glass vial obtained from the manufacturer.

There was no statistically significant change in IC₅₀ between ranibizumab stored in plastic syringes for 4 weeks compared with drug obtained from a fresh glass vial (p = 0.4883). Similarly, there was no statistically significant change in IC₅₀ between aflibercept stored in plastic syringes for 4 weeks compared with drug obtained from a fresh glass vial (p = 0.6202).

Compounding of ranibizumab and aflibercept in plastic syringes with storage for up to 4 weeks does not appear to have a detrimental effect on the in vitro functional activity of these medications. Because the cost of these medications can be prohibitive, compounding may be considered as a method of reducing cost.