Dropping a Throwing Weapon & Range Increment

If you drop a throwing weapon from a height onto an enemy, does that incur range increment penalty, and if so, how much? I am asking, because a question in our group came up whether gravity or higher ground rules apply to "Throwing" a weapon downward, but we could not find anything.

For instance: My Paladin Sir Isaac, is standing on a bridge, and there is a goblin below him, 60 ft. He attempts to drops an alchemist flash on top of the Goblin’s head.