Final answer:
The unique vial described in the question is the ADD-Vantage container, which keeps the medication separate from the diluent until it is time to reconstitute, helping to save waste with expensive drugs.
Step-by-step explanation:
The subject of this question is Medicine. The unique vial being described is the ADD-Vantage container, which is a specific type of container used for reconstituting medications. It keeps the medication separate from the diluent until it is time to reconstitute, which helps prevent waste, especially when using expensive drugs with a short shelf life after preparation.
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