.22 micron filtration is the pharma standard but most UGLs use .45, does the difference actually matter?

[HighAltitude]

Was reading about AP using .22 micron Whatman polycap filters and started wondering whether this is a meaningful quality distinction or just marketing. I understand .45 micron removes visible particulate but I've read that bacteria can still pass through at that pore size. Does the filter spec on a product tell you anything real about safety or is there no way to verify this from the outside? Asking because I'm trying to figure out what quality indicators actually mean something.

[Davo]

The .22 micron distinction is real and it does matter. .45 micron removes visible particulate and most larger organisms but certain bacteria are small enough to pass through. .22 micron is sterilising filtration in the pharmaceutical sense - it's what separates a properly sterile injectable from one that's just visually clear. The visual clarity of the oil tells you nothing about bacterial load. PIP that's disproportionate to the compound and concentration three or four days after injection is the warning sign something isn't right.

[SWE LIFTS]

I asked AP directly about this once. They confirmed the .22 micron Whatman polycap filter. The difference in practice is that a .22 micron filtered product can be considered sterile by pharmaceutical standards - it's not just clear, it's actually had viable bacteria removed. Most UGLs don't advertise their filter spec at all which is itself informative. Any lab using fake NDC numbers across all their products is a red flag that other shortcuts were taken too.

[Geoff K]

Never thought about filter specs before reading this. So essentially clear oil is a necessary but not sufficient condition for a safe product. Good to know there are actual verifiable quality markers beyond just visual inspection. I'll be paying more attention to this when evaluating products going forward.

[CaliBro]

The NDC number trick is worth knowing. Legit pharma products have unique NDC numbers assigned per product, per manufacturer, per package size. If a UGL lists the same NDC number across their entire product line they made it up. Takes about 30 seconds to verify on the FDA NDC database.

[MunichMarc]

Thank you for explaining this clearly. In Germany we are generally careful about pharmaceutical standards but with UGL products there is no official framework to evaluate them. The .22 micron standard is a useful concrete reference point I can actually apply when comparing sources.

[ScouseLad]

never knew any of this mate. so basically clear oil doesnt actually mean its safe? thats a bit worrying looking back at some stuff ive seen. will definitely be paying more attention to where things come from going forward. that ndC number trick is well useful