In a joint study carried out by Gerresheimer, Sterigenics and Früh, it could be shown that also NO 2 is well suited to terminally sterilize prefilled ophthalmic syringes. In detail 5 topics were addressed: (1) Compare EtO vs. NO 2 penetration into the filled syringe; (2) Analyze gas ingress though 4 different plunger stoppers including silicone oil free and standard rubber plungers; (3) Scrutinize gas ingress through 2 different cap designs based on different elastomer properties; (4) Investigate gas permeation through COP plastic barrels compared to glass; (5) Check if the Tyvek®-layer has an influence on either sterilization.Depending on the needs a suitable sterilization method, packaging and syringe type can be suggested to customers.