I would try and filter out the fillers first, as they most likely wont dissolve into anything.
Try to get a very fine meshed metal strainer, soak the cap contents in alcohol, then dump the liquid through the strainer.
If that doesn't get everything, you can repeat using a coffee filter, but you will most likely lose some active as it soaks into the filter. This should get all the filler out, though.
Trust me, rubbing filler onto your skin is not fun.