New sterilizer: preliminary study of hydrogen peroxide (H2O2) diffusion through different medical devices

The production unit uses a vapor state hydrogen peroxide (H₂O₂) as a sterilization process of an isolator for the preparation of standard pockets and infusers. H₂O₂ is known as a potent oxidizing agent, toxic to the body. The objective is to evaluate the diffusion of H₂O₂ through primary packaging and overpacking in the context of qualification.

H₂O₂ was dosed by UV spectrophotometry (validated method) at D0, D1, D2, D15, D21 (WYM infusers (silicone tank, polyethylene teraphthalate ester shell) and Auto Fuseur (silicone tank, polycarbonate shell)) or D35 (tri-layer barrier pockets) of each filling. They were sterilized empty with overpacking and filled immediately or after storage for 8 days (n=3 per category). The mean concentrations of H₂O₂ found in the two types of infusers were compared (Student test).

H₂O₂ dosage method is linear (100-1000 ìg/L), accurate (95% CI=88.0-113.3 ìg/L) with a limit of quantification of 100 ìg/L. In NaCl bags, used as dilution solvant, H₂O₂ is not detected (<100 ìg/L from D0 to 35). The same results are observed with Auto Fuser filled immediately (<100 ìg/L from D0 to D21). For Auto Fuser filled after storage, H₂O₂ concentration reaches 186.2 ìg/L at D15. For the VYMs, a concentration superior than 100 ìg/L is observed independently of the filling since D1 (filled immediately: Student p <0.05, Peak D15: 710 ìg/L). For the barrier bags, a permeation of H₂O₂ is observed at D15 (heterogeneous results due to the small number of samples): 314 ìg/L (filled immediately) and 239 ìg/L (filled after storage).

Considering the results, it seems that the type of overpacking of the infuseur influences the permeability of H₂O₂. This parameter is a selection criterion for the choice of the medical device and bag for the preparation in isolator.

Rates higher than 100 ìg/L found after 8 days of storage tend to use the devices as soon as possible after sterilization.