The active ingredients of cosmetics are largely divided into fat-soluble and water-soluble ingredients.
Fat-soluble ingredients are Vitamin A/Retinol, Ceramide, Fat-Soluble peptide and etc.
Collagen Hyaluronic acid, Vitamin C, and Adenosine are water-soluble ingredients.
The skin barrier consists of keratinocytes and lipids to protect and prevent external harmful substances from entering and penetrating.

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  Water-soluble ingredients can pass Keratinocytes, but not block fat-soluble components.

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  Lipids let fat-soluble components to pass through but blocks water-soluble components.

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  The problem is that the skin barrier is constructed
  as overlap structure of keratinocytes and lipids.

  This insinuates that water-soluble ingredients cannot pass through lipids,
  and fat-soluble ingredients cannot pass through keratinocytes,
  hence none of the ingredients can easily pass through the skin barrier.

In fact, skin barrier penetration rate of well-known active ingredients is very low such as Vitamin C resulting 0% and Retinol 0.28% according to
“The Study on the Skin Penetration of Cosmetic Ingredient with in vivo Raman Spectroscopy and in vitro Franz Cell”.

Source: Se-rim Jeon, Min-he Han, Dae-gyun Jung, Jae-seong Hwang (2014).
In vivo skin permeation measurement and in vitro comparative evaluation of functional cosmetic ingredients using a Raman spectroscopic skin analyzer. Vol 40 No. 1 [2014]