Mast prop held perfectly and without pain at 100mg/ml with 2/20 in grapeseed oil. IDK about mast E, yet. IIRC, Bill Roberts said it should hold at 200mg/ml.
Just a note on the var, (that I'm sure you've thought of,) if I were you, I'd turn this into an oral solution to ensure accurate dosing since it's for your wife. (As opposed to capping it.) AFAIK, var is pretty hard to go into solution, but IIRC, I've read it'll hold at 10mg/ml in everclear. Someone correct me if that's incorrect.