This is misinformation and errors. Skin Inc. got the article from a dot com not a science source. It is old and could be very misleading.
I am disappointed with Skin Inc. for reproducing it with out looking at it critically and scientifically.
Our stratum corneum is water permiable but thank goodness the lower layers are water tight. We wouldn't be able to bath.
Thank good ness our skin protects us and is not permiable to toxins. We can use sunscreen with out it penetrating to our blood stream.
Vit. A and Vit C derivatives have been around for 25 years. The science was to get a molecule small enough, safe enough and still maintain the chemical properties to be beneficial to and target the needs of the skin with out being toxic.
It is easy to penetrate skin. Just stick your hand it a bucket of gasoline and see what happens. Toxic. but it would be a great carrier.
It is not so easy. I am glad my skin protects me from environmental toxins.
To benefit the skin is a complicated molecule. They are big they do not absorb so easily. There is more science then this article leads you to believe.