Every dilly I have ever done, prepped perfectly! Even the M's or mallinkrodt generic HMs. I have had them from 2mg-8mg tabs and just about every generic, mostly got the brand name dilaudids when I still used them, but I had all of the other generics... and the M's left the most powder behind after pulling up the solution, the brand name were the best, obviously, and melted right into the water anywhere from cold to room temp.. or even warm is fine, as Raysu pointed out.. doesn't really matter just as long as your not cooking them or using scolding hot water!!! OP I hope you know not to cook any type of pill for IV preparation. It makes lots of the inactive binders/fillers dissolve in with the dilaudid, which of course you don't want(I mean the fillers/binders, obviously you want the dilaudid)... I always went with at least 50 units, because that's just how I have always done it, I'm sure you would be fine with like 30units too, but any less than 30 units or 0.3 ml of water on one dilly is probably going to make the solution a bit too thick... 50 units has it nice a thin, clear and easy to work with when stirring it and pulling it up, plus if you start to inject and miss part of the shot, you have more water to work with so your not wasting as much if you miss like 5-10 units of the HM solution when you use ~50-80 units, as you would with 30units or less. I have know idea why you wouldn't be able to mix these d's you have as they aren't too much different than the Purdue P2 dilaudids.. just a bit more filler. how much water do u use to prep them?