Dear friend, I have to tell you that studies show that slight differences in formulations make big differences among patients. So you'd better consult your contact seller before buying any kind of contact lens solutions. I also think that you cannot use your friend's solutions. if he or she had eye infections, you may get the same problem by using his or her solutions.
I don't think all contact lens solutions are created equal. Although we often heard that the practitioners will tell us that all contact lens solutions are the same, patients can choose whichever they want, but the slight difference in the solutions may cause red eye and other symptoms. I think you'd better ask the practitioners which kind of solution is best for a special brand. You can't use your friend's solutions.