If skin is a watertight barrier, how do medicinal creams work?

Question

If skin is a watertight barrier, how do medicinal creams work?

In: Biology

Answer 1

Its not watertight, its semipermiable.

You have cells that act as a sort of mesh. They allow some things in and some things out. Medications can be transpported into those cells when applied to the skin and they can transport that to other cells and into the blood.