It won't be absolutely pure, but you can crush them, dissolve them in 99% methyl alcohol, filter them through a good filter paper, or paper coffee filters if it's all you can get and let the alcohol evaporate slowly in a shallow pan (like a pie plate) on very low heat, or better, in a dark place naturally.
I've don this with all sorts of pills, but never adderall, as you couldn't get them in Canada when I was into this bullshit. It grabs some of the crap, but leaves out most of the sugar and chalky binder. Makes it a hell of a lot easier on the nose, if that's what you have in mind, which I'm pretty sure you do. You will be losing a little, but if you have a lot, it's no big loss.