I don't know about you, but I've never had trouble dissolving DMT freebase in water. It is a little polar and 50mg should easily dissolve in a few ml of water in my experience. I've never IV'ed DMT though and I don't intend to since smoking usually does the trick for me.
since smoking will require triple the amount of IVed dmt to induce a breakthrough
You sure about that factor? Triple sounds a bit high.
If you just want to IV this to make your white DMT go a longer way and can get yellow/orange DMT much easier, there are ways to clean DMT. Here are a few options, ideally you perform all of them in that order:
-Form salt in acidic water, pull with non polar to remove non polars
-Add base, pull with non polar to extract DMT freebase
-Add 1g DMT to 20ml IPA, add 300mg activated charcoal, keep at 60°C for a day (make sure air can't escape or the solvent will evaporate)
-Filter out charcoal
-Evaporate solvent
Note: Btw the dirtier it is, the more charcoal you should use. For light yellow DMT I'd use no more than 250mg, for dark brown stuff up to a gram
-Recrystallize at least once in heptan to yield shiny white crystals.
The extract I yielded the very first time I did this was supposedly over 99.9% DMT according to GC/MS. I presonally can't verify this, but have had multiple sceptics look at the results...
Just saying, this isn't hard or expensive to do and you can get very very clean shit from the dirtiest DMT.