Overfill in Compound Pharmacy Vials

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ilateapex

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When a compound pharmacy gives you an overfilled vial, does that mean the concentration is still at full strength, or did the extra volume water it down? In other words, is the overfill just additional BAC water thrown into the mixture, or is the vial drawn from a large pre-mixed container and simply filled with more liquid than intended?

I am wondering whether this explains why certain vials feel stronger than others. Right now I am still going through compound while I wait for the US warehouse of gray to be back in stock.
 
While I was still in the compound world, I attempted to make this point, but the Redditors simply couldn't accept that what was added was probably just extra liquid. In reality, that means the concentration ends up a bit lower, which would probably leave you with a slight underdose. They kept insisting it was bonus Tirz. Once you do your own reconstitution, with a trustworthy COA or a 3rd party test confirming the true overfill, the math becomes far clearer.
 
That matches my own suspicion. Still, since I don’t know how they handle reconstitution at scale, I doubt it happens vial by vial.
 
With Brello, the Rx label listed both the concentration and the dose in units. Because the vials contained more than labeled, a 3-month supply stretches to nearly 4 months. The prescription ought to state the dose (volume) and the concentration. Anything beyond that is a bonus.
 
ilateapex said:

That matches my own suspicion. Still, since I don’t know how they handle reconstitution at scale, I doubt it happens vial by vial.
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At 503B pharmacies that handle large volumes, the compound is batched before any vials are filled, and a single batch can produce over 10,000 vials. There is no dilution happening when overfills occur.
 
chewonmysac said:

While I was still in the compound world, I attempted to make this point, but the Redditors simply couldn't accept that what was added was probably just extra liquid. In reality, that means the concentration ends up a bit lower, which would probably leave you with a slight underdose. They kept insisting it was bonus Tirz. Once you do your own reconstitution, with a trustworthy COA or a 3rd party test confirming the true overfill, the math becomes far clearer.
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I have to disagree — that logic doesn't hold up. No one is putting the compounded solution into a vial and then pouring in some unknown extra fluid just to produce an overfill. The reason people pushed back is that following your advice could cause someone to take too large a dose.

Blueeyedme said:

ilateapex said:

That matches my own suspicion. Still, since I don’t know how they handle reconstitution at scale, I doubt it happens vial by vial.
Click to expand...
At 503B pharmacies that handle large volumes, the compound is batched before any vials are filled, and a single batch can produce over 10,000 vials. There is no dilution happening when overfills occur.
Click to expand...
That's the correct explanation.
 
Overfilling happens even with pharma products. I figure it's a matter of built-in tolerances so that underfilling—which is a much bigger issue than overfilling—doesn't occur. My wife used zepbound vials that came directly from EL, and the concentration was meant for 0.5ml, yet the actual fill usually landed somewhere between 0.65 and 0.7ml. As for me, I'm on trt (compound now, but pharma in the past), and the 1ml pharma bottles tend to be filled to around 1.1 or 1.2ml for the same reason. I'm fairly confident this is just standard practice to prevent underfills and account for other variables.
 
Mood said:

Overfilling happens even with pharma products. I figure it's a matter of built-in tolerances so that underfilling—which is a much bigger issue than overfilling—doesn't occur. My wife used zepbound vials that came directly from EL, and the concentration was meant for 0.5ml, yet the actual fill usually landed somewhere between 0.65 and 0.7ml. As for me, I'm on trt (compound now, but pharma in the past), and the 1ml pharma bottles tend to be filled to around 1.1 or 1.2ml for the same reason. I'm fairly confident this is just standard practice to prevent underfills and account for other variables.
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That's spot on — those single dose vials always contain at least .65. The extra is a deliberate, uniform overfill meant to cover a device failure. In practice, that's medication you don't pay for. From what I've seen, plenty of users simply extract every last drop, so the dose they actually get runs higher — and at 10mg + vials, considerably higher.
 
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