In packaging, a sealed glass container used in the distribution of pharmaceutical products. An ampule contains a single dose of a medication, commonly one used for hypodermic injection. It is formed out of a single piece of glass, and is hermetically sealed by flame at the open end. It is opened by snapping off the top along a scored portion of the stem. The important consideration in the manufacture of glass ampules is that the glass be completely inert chemically and not react in any way with the drug contained within it. Also spelled ampul and ampoule. See also Vial.