Sterilization of infusion bags : is removing the secondary packaging safe?

Objective
APS93^® is mix of peracetic acid (PAA) and hydrogen peroxide (HP) used to sterilize medical devices when entering a sterile isolator. Removing the secondary packaging of incoming infusion bags helps prevent the microbiological contamination of the isolator. But PAA and HP are known for their oxidizing properties and risk of permeation with some plastics, resulting in drug degradation and toxicity or inefficiency. Our goal was to determine whether the sterilization of unprotected infusion bags with APS93^® was safe.

Method
A review of the literature was conducted via pubmed and the GERPAC database using the following search terms: “peracetic acid”, “hydrogen peroxide”, “isolator”, “infusion bags” and “permeation”.

Results
Three articles studying the permeation of APS93^® or using PAA and HP concentrations mimicking APS93^® (5% and 20 to 30%) were selected. Polyolefin/polyamide (PE/PA) bags (Viaflo^® Baxter), polyvinyl (PVC) bags +/- DEHP (Rythmic^® set, Micrel med, Macoperf^®, Macoflex^® Macopharma infusion bags) and polyolefin (PE) (Freeflex^® Fresenius) were cited twice. Polypropylene (PP) (SLB bag^®, SLB Medical) and polyolefin/polyester bags (no brand cited) were studied only once. After analysis, only 2 articles studied the effect of PAA and HP, the other one examined the effect of PAA alone on the infusion bags. Contact time ranged from 6 min to 6 hours for PAA and 6 to 30 min for HP. Multiple bag sizes (50 to 500mL) were tested. Results showed that PE/PA bags were exempt from PAA and HP permeation(1,2). PAA was found in PE bags(3). HP was present in empty PP bags and PVC bags (Rythmic^® set)(2). For all filled PVC bags, results were conflicting; one study showed no permeation of PAA(1) while another resulted in the presence of PAA and HP(3).

Discussion-Conclusion
PE/PA bags seem to be the safest. HP permeation is less studied as its oxidative properties are less powerful than PAA, yet, HP has a high migrating power and spreads through some plastics. Bag sizes also affect the permeation process, higher contact area favors permeation. Results, presented here, need to be supported by new studies with infusion bags of the same plastic composition as previously reported. These results must be taken with caution if they were to motivate a change in practice.

1. Havard et al. Evaluation of peracetic acid permeation during flash sterilization through pharmaceutical plastic polymers used in cytotoxic reconstitution units. août 2005
2. Méthode de détection pour l’étude de la perméabilité à l’agent de stérilisation des dispositifs médicaux utilisés sous isolateur. GERPAC, 2007
3. Müller H-J et al. Permeation of gaseous hydrogen peroxide and peracetic acid into IV bags during their surface sterilization. févr 2003;

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