Eight fields that make a reconstituted vial auditable: mass, diluent volume, concentration, both dates, units per dose and entries.
Key points
- 01Two records, one on the vial and one off it. The vial carries the few things you need at the moment of drawing: concentration, mix date and discard date. The log holds everything else, because a label large enough for the full history does not fit on a 3 mL vial and gets peeled off anyway.
- 02The three numbers that define the vial. Mass in milligrams from the label, diluent volume in millilitres as you actually measured it, and the concentration those two produce. Recording the volume you added rather than the volume you intended is what makes the concentration trustworthy weeks later.
- 03Two dates, not one. Write the date you reconstituted it and, on the same line, the date you will discard it, worked out at mixing time rather than looked up in a hurry later. A discard date computed once and written down is the single most useful line in the log.
- 04Units per dose, with the syringe named. Record the dose in milligrams, the volume in millilitres, and the unit count together with the syringe it applies to, since a U-100 barrel and a half-unit barrel read the same volume differently. That line is also what you check the arithmetic against next time.
- 05One line per draw. Date, unit count and site takes five seconds and answers the question that otherwise ruins an evening: whether today's dose has already been given. It also shows how many times a multiple-dose vial has been entered, which matters for the beyond-use window.
- 06Lot number and anything unusual. Keep the lot number from the carton so a recall or a product complaint has something to reference, and note excursions as they happen: a power cut, a warm car, a vial that travelled. Storage history is impossible to reconstruct from memory and easy to write down once.
Frequently asked questions
What should a reconstitution log contain?+
Mass on the label, the diluent volume you measured, the resulting concentration, the mix date, the discard date, dose and unit count with the syringe type, a line per draw, and the lot number. Not medical advice.
Is writing it on the vial enough?+
For the moment of drawing, usually yes: concentration, mix date and discard date. A vial label has no room for the draw history or the lot number, and labels get peeled off or smudged, so the log holds the rest.
Why calculate the discard date at mixing time?+
Because that is when you have the information and the attention. A date computed once and written down removes the temptation to estimate a beyond-use window later, when the vial is in your hand and you want to dose.
Does a log help with a multiple-dose vial?+
Yes. A line per draw shows how many entries the stopper has had and how much solution should be left, which is a useful cross-check against both the beyond-use window and your own arithmetic.