If a topical goes down the pore, it primarily will affect that area. If you get penetration through the skin itself, and into the blood stream, you will get more systemic effects, in addition to penetrating the follicle from multiple directions.
Just because the scalp can get saturated does not mean it is no longer absorbing stuff. Saturation just means you can't increase the concentration, because the same amount that is going in is also leaving into the blood stream.
A high alcohol vehicle will put more minoxidil into the scalp than a high PG vehicle. But the PG vehicle is better because it does not evaporate, and gives a slower, longer dose that grows more hair. The high alcohol vehicle would probably give more systemic effects.
So think twice about trying to get more of a topical into your skin. There is a trade off.
Just because the scalp can get saturated does not mean it is no longer absorbing stuff. Saturation just means you can't increase the concentration, because the same amount that is going in is also leaving into the blood stream.
A high alcohol vehicle will put more minoxidil into the scalp than a high PG vehicle. But the PG vehicle is better because it does not evaporate, and gives a slower, longer dose that grows more hair. The high alcohol vehicle would probably give more systemic effects.
So think twice about trying to get more of a topical into your skin. There is a trade off.