Dr. Toufuu: I think, that a change of forms in her current mental
state could trigger a complete reversal of the memory
manipulation.
Nabiki: You mean, Ranko would remember everything again?
Dr. Toufuu: No, she would forget everything about her male side.<<
I don't see any big problems. When in one state, male or female, he/she will simply not remember his/her other side. I suppose Ranko will remember when Ranma is around and vice versa. Funny as it is, this doesn't sound as urgent as when Akane got hit with the same potion.