If we apply Minoxidil and it gets absorbed, and after 2 hours we sweat, will the sweat take out Minoxidil along with it?

Ideally minoxidil should be left on the scalp for 8 hours but the 'minimum' time I advise is 4-6 hours. After 4 hours, a high proportion (ie nearly 3/4) of the minoxidil is absorbed.This advice comes from a study done nearly 30 years ago. In that study, 22 men. The researchers examined how much minoxidil is absorbed at 1 hr, 4 hr compared to 11.5 hours. Relative to the amount absorbed after a contact time of 11.5 h, absorption was approximately 50% complete by 1 h and greater than 75% complete by 4 h. Although minoxidil should ideally be left on 8 hours, tremendous benefit can still be achieved with 4 hour use. If a person is sweating it off after 2 hours, it may be less effective. However, I would suggest discussing all the details with a specialist.
Reference
Ferry JJ et al. Relationship between contact time of applied dose and percutaneous absorption of minoxidil from a topical solution. J Pharm Sci 1990 Jun;79(6):483-6.