Can I filter a Reta vial that's already been in use for 8 weeks?

Amino74

Explorer
Joined
May 30, 2026
Messages
9
Reaction score
0
Location
UK
Since bacteria can multiply in a vial once it's been reconstituted, I'm wondering whether anyone has facts or opinions about filtering a vial that has already been mixed and used for roughly 8 weeks.

Would running it through a filter again help stop more bacterial growth?

For context, I have Reta 100mg that I reconstituted with Hospira, and I'm using under 3mg per week, so I'd like to know if filtering it once more could stretch out how long the vial stays usable. Thanks!
 
That's a solid question, and I like the way you're approaching it — though sadly I don't have an answer for you lol. But let's say it works just the way we'd hope and restores the vial to like-new condition: the degradation would still be there to contend with. At that point, wouldn't splitting the solution and freezing half of it until you need it give you roughly the same outcome? A single freeze-thaw cycle will cause some harm to reta, but is that harm comparable to leaving it reconstituted for 12-16 weeks?

I'm sure somebody will chime in with one of those charts showing purity after reconstitution next to the degradation from a single freeze cycle.
 
Amino74 said:

Since bacteria can multiply in a vial once it's been reconstituted, I'm wondering whether anyone has facts or opinions about filtering a vial that has already been mixed and used for roughly 8 weeks.

Would running it through a filter again help stop more bacterial growth?

For context, I have Reta 100mg that I reconstituted with Hospira, and I'm using under 3mg per week, so I'd like to know if filtering it once more could stretch out how long the vial stays usable. Thanks!
Buying R100 and reconstituting it when you're only using 3mg/week makes no sense to me. At that rate you'd get 33 doses, weeks, or roughly 8 months out of it. I could stretch to 12 weeks, but not that long. I do have R100 and R140 on hand, though my wife and I run 20mg/week.
 
If bacteria are growing in there, filtering it and then injecting is not something I'd do. I'd throw it out, no question. And I'm higher risk than most people. I'd pick up an r30 kit and run it for 10 weeks. Hold on to your r100 for later, in case you titrate up.
 
Re-filtering could trap bacteria, but it won't remove the endotoxins they leave behind. On top of that, each additional draw and transfer creates one more opportunity for contamination — so you'd be introducing risk in an attempt to remove risk. The benzyl alcohol in bac water exists to slow growth between draws; it isn't meant to keep a vial usable indefinitely, and opened multi-dose vials are typically given a window of about 28 days. If a vial can't be finished within a reasonable timeframe, the cleaner solution is to use a smaller vial. That's cheaper than a rough week, mate.
 
Amino74 said:

Since bacteria can multiply in a vial once it's been reconstituted, I'm wondering whether anyone has facts or opinions about filtering a vial that has already been mixed and used for roughly 8 weeks.

Would running it through a filter again help stop more bacterial growth?

For context, I have Reta 100mg that I reconstituted with Hospira, and I'm using under 3mg per week, so I'd like to know if filtering it once more could stretch out how long the vial stays usable. Thanks!
When I think about dealing with a large vial of liquid, my approach would be to get a batch of fresh sterile vials and split the whole amount into portions that are practical to use. Given how quickly you go through it, I'd aliquot 33mg into each of 3 new vials, then use one vial over 10 - 11 weeks.

You'd do the same with the remaining 9 reconstituted 100mg vials, but only when you need them — nothing gets punctured until you're ready to use it. The vials you aren't using yet can go in the fridge, and since they stay unpunctured until you divide them up, that should keep them in good shape. Once a vial is punctured, the clock starts ticking.
 
Running an old vial through a filter again won't make it safe. A filter traps bacteria, but it can't remove the substances those bacteria leave behind, and those leftovers are what could make you ill. The result would be a vial that appears clean while it isn't.

There's another problem: 100 mg at under 3 mg a week works out to a 35 week supply in a single vial, and no vial ought to stay open for that long. Going forward, divide it up: reconstitute smaller quantities so that each vial is finished in roughly 8 weeks. As someone pointed out, this won’t fix the degradation issue.
 
BNLFL said:

Buying R100 and reconstituting it when you're only using 3mg/week makes no sense to me. At that rate you'd get 33 doses, weeks, or roughly 8 months out of it. I could stretch to 12 weeks, but not that long. I do have R100 and R140 on hand, though my wife and I run 20mg/week.
Because it was priced so well, stocking up on the larger quantity seemed like the smart move
 
Shittersfull said:

If bacteria are growing in there, filtering it and then injecting is not something I'd do. I'd throw it out, no question. And I'm higher risk than most people. I'd pick up an r30 kit and run it for 10 weeks. Hold on to your r100 for later, in case you titrate up.
I can't spot any bacteria with the naked eye, but I figure they'll build up as the vial gets older. I'll definitely set these big ones aside for later — thanks.

John_C said:

Re-filtering could trap bacteria, but it won't remove the endotoxins they leave behind. On top of that, each additional draw and transfer creates one more opportunity for contamination — so you'd be introducing risk in an attempt to remove risk. The benzyl alcohol in bac water exists to slow growth between draws; it isn't meant to keep a vial usable indefinitely, and opened multi-dose vials are typically given a window of about 28 days. If a vial can't be finished within a reasonable timeframe, the cleaner solution is to use a smaller vial. That's cheaper than a rough week, mate.
Understood, appreciate you sharing that.

AngieHolmes said:

When I think about dealing with a large vial of liquid, my approach would be to get a batch of fresh sterile vials and split the whole amount into portions that are practical to use. Given how quickly you go through it, I'd aliquot 33mg into each of 3 new vials, then use one vial over 10 - 11 weeks.

You'd do the same with the remaining 9 reconstituted 100mg vials, but only when you need them — nothing gets punctured until you're ready to use it. The vials you aren't using yet can go in the fridge, and since they stay unpunctured until you divide them up, that should keep them in good shape. Once a vial is punctured, the clock starts ticking.
Might give this a try for the next 1 or so, but I'll probably just pick up some 30s or 40s next time and hold the larger ones in the stash. Thanks.

quietone said:

Running an old vial through a filter again won't make it safe. A filter traps bacteria, but it can't remove the substances those bacteria leave behind, and those leftovers are what could make you ill. The result would be a vial that appears clean while it isn't.

There's another problem: 100 mg at under 3 mg a week works out to a 35 week supply in a single vial, and no vial ought to stay open for that long. Going forward, divide it up: reconstitute smaller quantities so that each vial is finished in roughly 8 weeks. As someone pointed out, this won’t fix the degradation issue.
I'd hoped filtering would take care of it, but it's good to know. Thanks for the info.
 
Back
Top