I don't know this compound. But I would try citric acid - buy food grade at the grocery store or health food store. Some needle exchanges stock it for among other things dissolving crack cocaine in water for injection. I recommend you don't use vinegar, but you could use a tiny a tiny amt to see if acidification is the solution, no pun intended. Citric acid / vinegar will lower the pH of water and assist freebases and some other water insoluble compounds to dissolve.
I doubt you need to raise the pH, but l could be wrong. You could try an alcohol, or alcohol/water mixture, but for nasal sprays that may well be very likely to be uncomfortable...
To raise pH (make more basic solution) use something like a tiny amt of ammonia AND check the pH of resulting solution with pH paper b/f use. Any pH above about 7.5 may burn like hell and do damage, and possibly degrade the dissolved compound.
