Unfortunately
@phishhead, this sort of a posting implies that you are possibly considering to distribute a cut product (can be a good thing for heroin as it reduces overdoses but the fentanyl takes the problem to a much higher level).
that is
implies so you may not get any responses, though.
I strongly suggest that you read this report on adulterants and bulking agentsI also urge you to get a Fentanyl testing kit so you know where you stand plus so that can avoid killing others and yourself included. I don't need to tell you that if not done carefully, then you could be up for a homicide charge if not intent to supply and/or ongoing supply.
Much luck and do read that article, it is extensive.