Due to the customs issues, we are using discrete or stealth packages to send. While the packages are not sterile. Sterile steroid oils are not available. So we have to make the oil conversions sterile and safe for intramuscular injection.
To make sure the injection safety, there is a very effective and it's the ONLY one further process need to be done with our oil - the sterile filtration. We use membrane filtering with 0.22 or 0.45 um filter membrane for all the oils we offer. Well, 0.22 um pore size is recommended.
As for filter membrane materials, the PES filters will not go well with benzyl alchohol and benzyl benzonate, the recommended is Nylon, PVDF and PTFE.
With a sterile container, the filtered oil conversions can be received for refilling or rebottling into sterile vials (usually means 10ml).