Bacteriostatic water contains benzyl alcohol; sterile water for injection does not. The difference matters when a container will be entered repeatedly over days and matters much less for a single-use preparation.
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Practice · Reconstitution · continued
Foaming during reconstitution and whether it matters — the long version posts 31–60
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
r.mensa, post #3: Noted, and I have changed what I was going to do on the strength of it. Go to post
Reframing Foaming during reconstitution slightly, because I think the disagreement is about the question rather than the answer. If the question is "does it happen", yes. If it is "how often", nobody here knows.
Building on post #34 rather than restating it.
Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile indefinitely, and no supplier claims otherwise.
That is what I would do. It may not be what is correct.
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h.frisk, post #34: The documentation on Foaming during reconstitution is better than this thread and I say that as someone who has posted in the thread. Go to post
Post #33 put the caveat in the right place and I want to underline it.
Adding what did not work for me on Foaming during reconstitution, since the failures never get written up and they are half the useful information.
policy_reader, post #8: Adding the measurement that post #7 says would settle it. A request rather than an answer: could whoever has the primary source for Foaming during reconstitution post it? I have seen the claim three times this month and each version had lost a qualifier. Go to post
Do not shake. Swirl, or leave it. Vigorous agitation introduces air and shear, and neither helps a peptide go into solution any faster than patience does.
Worth stating the null on Foaming during reconstitution before we explain it: the observation may be nothing. That possibility deserves a sentence and usually does not get one.
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Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile indefinitely, and no supplier claims otherwise.
The interesting part of this is the exception, and I do not understand the exception.
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l.chevalier, post #25: Do not shake. Swirl, or leave it. Vigorous agitation introduces air and shear, and neither helps a peptide go into solution any faster than patience does. Go to post
Everything in post #41 holds. The case it does not cover is the one I have.
Foaming during reconstitution sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable side, narrowly.
m.stephanopoulos, post #15: Add the diluent down the side of the vial rather than directly onto the cake. It is slower and it avoids the foaming that makes people think something has gone wrong. The short answer was in the first line; everything after is the working. Go to post
Narrowing post #41, because the general version has more than one answer.
Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile indefinitely, and no supplier claims otherwise.
I have separated what I observed from what I concluded, which does not always happen.
Taking post #45 at face value and following it one step further.
Foaming during reconstitution looks different depending on whether you are reading the primary literature or the summaries of it, and the difference is not in our favour.
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i.balogun, post #32: Good question, well framed, and I would like to see it answered properly. Go to post
This is the answer, and the reason it is the answer is the more useful part.
c.serrano, post #22: Write the reconstitution date and the concentration on the vial. Not on a note, on the vial. Every account here of a dosing error involving the wrong concentration involves a vial with nothing written on it. Go to post
Do not shake. Swirl, or leave it. Vigorous agitation introduces air and shear, and neither helps a peptide go into solution any faster than patience does.
Worth separating two things that post #45 runs together.
The best check on any reconstitution calculation is to do it twice by two different routes — mass per volume, then volume per dose — and see whether they agree. They should, and when they do not it is nearly always the concentration step.
Adding this to the thread rather than to the wiki, because I am not confident enough for the wiki.
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e.coelho, post #43: Everything in post #41 holds. The case it does not cover is the one I have. Foaming during reconstitution sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable side, narrowly. Go to post
Saving this. It is the version I will quote when the question comes round again.
The arithmetic in post #51 is right; the assumption feeding it is the part to check.
Worth separating Foaming during reconstitution as a question about the compound from Foaming during reconstitution as a question about the documentation. They get answered by different people and only one of them is answerable here.
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Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile indefinitely, and no supplier claims otherwise.
It is the kind of thing that is obvious once and never again.
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s.chowdhury, post #40: Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile indefinitely, and no supplier claims otherwise. The interesting part of this is the exception, and I do not understand the exception. Go to post
My experience of Foaming during reconstitution contradicts the reply above. I am posting it as a data point rather than as a refutation, because one person's experience is exactly that.
Everything in post #54 holds. The case it does not cover is the one I have.
Answering the Foaming during reconstitution question as asked, then the question I think is meant. As asked: yes, with the qualification below. As meant: it depends on how the first measurement was taken.
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septum_check, post #48: Do not shake. Swirl, or leave it. Vigorous agitation introduces air and shear, and neither helps a peptide go into solution any faster than patience does. Go to post
I keep a log for Foaming during reconstitution specifically because my memory of it turned out to be systematically wrong in one direction. Six weeks of notes cost nothing and settled it.
r.mensa, post #3: Noted, and I have changed what I was going to do on the strength of it. Go to post
Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile indefinitely, and no supplier claims otherwise.
That is the honest state of it as of this week.