It would. That's 10 times the max solubility. You should be able to get somewhere close to 2% if you add a neutral salt (eg sodium chloride or sodium phosphate, or any other neutralisation product of a strong base/strong acid, but I think you would need quite a lot of it (say 5%) which might be uncomfortable on the skin as it dries.
Edit: you could consider using willow bark extract instead, which is nearly the same thing. You might still need to shake your bottle of serum a little to disperse everything, though you could possibly get around that by using an emulsifier.
Another edit: you should also ingest anything I say with NaCl. My background is chemistry/biochemistry/biotechnology, and I am not a dermatologist, doctor or witchdoctor.
Cool! I can get water soluble white willow bark extract liquid.
Do I use the same amount as salicylic acid?
@nav1 Salicylic acid has poor solubility in water, you'd need access to some pretty hardcore ingredients to make an alcohol free version. For example, this Salicylic Acid 2% from The Ordinary which is alcohol free, and atm is unfortunately out of stock. Its ingredients list should help you along.
https://deciem.com/en-au/theordinar...cylic-acid-2pct-solution_size=30ml&quantity=1
Ingredients in bold are what contribute to dissolving the Salicylic Acid, as well as the Citric Acid which I suspect is to lower the PH, also to help solubility.
Aqua (Water), Hamamelis Virginiana Leaf Water, Cocamidopropyl Dimethylamine, Salicylic Acid, Dimethyl Isosorbide, Trisodium Ethylenediamine Disuccinate, Citric Acid, Polysorbate 20, Hydroxyethylcellulose, Ethoxydiglycol, Potassium Sorbate, Sodium Benzoate, 1,2-Hexanediol, Caprylyl Glycol.
Thanks!
I'll check if I can get these ingredients locally.