Also, why would you want to turn the liquid diazepam into a powder? If you're looking to do that so you can snort it, then you are going to lose a lot of the diazepam. Diazepam has an oral bioavailability (BA) of 93%. It's intranasal BA is probably half that (if that, it's probably even lower). Why not just take it orally?
Also, there are many theads just like this as NeighborhoodThreat has already linked you to.
So therefore, I am closing this thread.