Stability of infliximab in polyvinyl chloride bags

Purpose. The stability of prepared infusions of the tumor necrosis factor (TNF)-α agent infliximab after storage for up to two weeks was investigated. Methods. To determine the feasibility of liberalized expiration dating of infliximab (current recommendations call for the infusion of prepared doses within three hours), the stability of diluted infliximab stored in polyvinyl chloride (PVC) bags at 4°C for up to 14 days was evaluated. A known quantity of TNF-a was combined with infliximab test samples in PVC bags for one hour; immediately after the reaction period and after 7 and 14 days of storage, the residual amount of TNF-α (an indirect measure of the drug's biological activity) was analyzed via a validated enzyme-linked immunosorbent assay (ELISA). Results. The mean ± S.D. amount of TNF-α consumed by infliximab was calculated to be 24.5 ± 5.6 pg/mL at baseline, 29.0 ± 4.4 pg/mL at 7 days, and 24.8 ± 17.3 pg/ mL at 14 days. At all evaluated time points, ELISA results indicated that 19-24% of the original TNF-α had been consumed by infliximab (mean ± S.D. consumption: 19.6% ± 4.5% at baseline, 23.2% ± 3.5% at 7 days, and 19.8% ± 13.8% at 14 days). Conclusion. Infliximab, when prepared at a concentration of 400 μg/mL in 0.9% sodium chloride injection, incurred no loss of biological activity when stored for up to 14 days at 4°C in PVC bags. Changing in- fliximab preparation practices may improve clinic efficiency by reducing patient dissatisfaction with long wait times for infusions and avoiding costly waste.