@newt @munir I don't think it's such a strongly controlled substance in most countries, I mean they they probably won't sell it to you in the nearest drug store in huge quantities, but otherwise it's not hard to get. At least that's what they usually cut cocaine with — were it any trouble, they'd probably be using something even cheaper.
But in any case, shouldn't you be treating the burns properly instead of all this? Of course I can't see how bad it is, but if it's just the fingertips you hardly need any pain remedy in the first place.