Again, highly concentrated material is bad for veins, and this has been stressed well enough.
If one were in a hypothetical situation where a sadistic viva examiner were expecting one to produce a litre of magnesium sulfate from sterile components, one would be forced to combine one litre of sterile water with 493g of raw magnesium sulfate powder.
One would be careful not to get any on oneself, lest it be absorbed through the skin. Apparently that’s a real threat.
Who cares about the sulfate ion?...
Somebody should. Poor sulfate is intensely hydrophilic and cannot traffic in and out of cells as perhaps it should, being of major importance in numerous critical cellular processes. Sulfate transporters are employed to facilitate its movements. What doesn't get into cells is excreted in the urine, with renal tubular resorption being the major means of maintaining a sulfate homeostasis at around 0.3 mmol/L.
The tragic fate of sulfate is well covered in this 2001 article. Yes, its not a physiologically relevant ion. No, nobody really measures it.