That depends on how long you draw on it in a single drag, and at what wattage (volts*volts/ohms) you are using said ce4 at right now......
So one drop is roughly equivalent to 1.5 drags for me,
there are approxamately 23 drops in a ml,
so you have about half that amount loaded and ready to go, or approxamately 20 drags.....
For me that amount would last just over one
vape session. But that is also dependant on what nicotene strength is loaded as well.