Update: Didn't really get a satisfying answer from Xyon. They just said it wouldn't be correct to follow the above calculations for topical solution.
Honestly, I was hoping this to be a 0.25% solution considering most studies were done on that concentration. 2.5% seems a bit tooooo high. Unfortunately, will give it a pass as I have not received a satisfactory answer on such a high concentration dose.
Just curious, anyone else thinking of trying this ?