This vial contains a red gel, and bulges at the sides.  Throw this potion at an area.  The bottle explodes, and the resulting expansion of crimson goo causes it to both increase in size, and rapidly cool to the point the surface of the gel resembles a leather.  The resulting air bag expands to fill a 10 foot cube, and throws all creatures caught in its area 15 feet, knocking them prone, unless a Dexterity saving throw of DC 14 is succeeded.  If successful, a creature simply moves to the edge of the cube's area.