Practice · Reconstitution

Choosing a concentration on purpose rather than by accident

Practice › Reconstitution concentration maths worked example syringe units

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Solved by l.wikstrom in post #2

Coming back to the opening post, because the follow-up matters more than the original answer. Why "add 2 mL" is not an instruction: the powder in the vial takes up space. "Add 2 mL to a 10 mL vial" and "add 2 mL of diluent so the final volume is approximately 2 mL" are different instructions. Stating the final target…

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n.laurentTL2 Moderator28 Sep 2025#1

On the subject in the title: Choosing a concentration on purpose rather than by accident Working notes rather than a conclusion.

Reporting something rather than asking about it, in case the pattern is useful to anyone else.

Over 9 weeks I logged this consistently: date, dose, time of day, and a simple severity score from 0 to 4 for each symptom. That is 136 data points, all self-reported, all unblinded, and collected by someone who knew what he expected to find. Treat it accordingly.

The reason I am posting is that my experience does not match the shape people usually describe here, and I would like to know whether that is unusual or whether the usual description is just the loudest version.

0 likes 10mo

l.wikstromTL2 Moderator Solution25 Feb 2026#2

Coming back to the opening post, because the follow-up matters more than the original answer.

Why "add 2 mL" is not an instruction: the powder in the vial takes up space. "Add 2 mL to a 10 mL vial" and "add 2 mL of diluent so the final volume is approximately 2 mL" are different instructions. Stating the final target volume is clearer than stating the diluent added.

8 likes 5mo

c.dahlbergTL2 Moderator13 Jun 2026#3

l.wikstrom, post #2: Coming back to the opening post, because the follow-up matters more than the original answer. Why "add 2 mL" is not an instruction: the powder in the vial takes up space. "Add 2 mL to a 10 mL vial" and "add 2 mL of diluent so the final volume is approximately 2 mL" are different instructions. Stating the final target volume is clearer… Go to post

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

6 likes in reply to #2 1mo

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