Handling and measurement
Lyophilised Powder
Last updated
Powder made by freeze-drying: the material is frozen and then the water is drawn off under vacuum, leaving a dry solid behind. Dry material keeps far longer than the same material sitting in water, which is why vials are shipped this way. What you see in the vial varies a great deal, from a firm white puck to a thin film on the glass to a few loose specks.
Why it matters here
You cannot judge the contents by looking at them. A small quantity of freeze-dried material genuinely can look like an empty vial, and the dried cake often breaks loose in transit and ends up stuck to the stopper or scattered up the walls, which looks like damage and usually is not.
What it is not
A vial that looks empty is not evidence that it is empty, and that is the most common panic after a delivery. It is not proof of the opposite either: how big and fluffy the cake looks depends on how it was dried, so a large cake and a barely visible film can hold the same amount, and only the label states the quantity.
Also called
- lyophilised powder
- lyophilized powder
- lyophilised
- lyophilized
- lyophilisation
- lyo
- freeze-dried
- freeze dried
- powder
- cake
Lyo is the short form and freeze-dried is the plain English one. Cake is the pharmacy word for the solid plug the drying leaves behind, so a collapsed or shrunken cake describes its appearance and is not a measure of what it contains.
Compounds carrying this term
None on file yet. This term is in the controlled vocabulary but no compound record currently uses it — which is a statement about our coverage, not about the term.