Penetration Enhancement of Hydrolysed Collagen

There are recently developed penetration enhancers that could be utilised to assist hydrolysed collagen (and other large molecular size substances) to penetrate further into the skin, (example: U.S. Patent 6,759,056: a transdermal delivery system that can deliver high molecular weight pharmaceuticals and cosmetic agents to skin cells) but in the case of collagen, why bother?

It has not been proven that introduced collagen plays any significant role in the development of new collagen in the human skin.
As previously discussed, for any of the peptides or nutrients present in the collagen to play any role in collagen development, they need to reach the fibroblast by means of microcirculation.
The question of how the introduced collagen achieves this even if it can be delivered transdermally still exists.
Even as a temporary dermal filler, the sheer quantity of collagen required to make a noticeable contribution over any given period of application is only practically delivered by volume injection.
Remember that any introduced (not manufactured by the body) collagen is a protein that is slowly digested down into amino acids and absorbed by the body, and even if the skin could absorb the collagen, it would be a losing battle as the quantity absorbed from the daily topical application would likely be insufficient to replace the collagen being digested during the natural process.

Preservative absorption

Another more important issue raises its head when penetration enhancers are used to deliver collagens to the lower levels of the epidermis; the matter of the large amounts of preservatives required to stabilise the collagen also find its way to the lower levels of the epidermis.

This could easily open Pandora’s box of allergy and dermatitis issues, in addition to potential long-term chemical effects.
The following ingredient list is taken from a typical product that is claimed to use a patented method to help collagen absorption in to the epidermis, and clearly illustrates my point about other non-desirable substances finding their way below the surface.

Ingredients: collagen (marine), distilled water/lgepal, cephene, methyl paraben, ethyl paraben, propyl paraben, butyl paraben, isobutyl paraben, synasol, serum protein, purified water, PRE complex, sodium methylparaben,imidazolidinyl urea, trisodium EDTA, potassium sorbate, citric acid, ascorbic acid.

The substances in red text are the preservatives that could ultimately find their way past the skin barrier defence systems. (The potassium sorbate is probably the most natural of the preservatives)

Of the eighteen ingredients, half of them are preservatives! 

Is this wise? Do we really want substances with potentially negative estrogenic effects (Parabens) and a formaldehyde-releasing preservative to penetrate the natural barrier defence systems nature put in place to keep such chemicals out?

As I have stated elsewhere, the cost of introducing the penetration enhancers to the
formulation to assist a largely ineffective (other than as a dermal filler) substance into the lower epidermis does not seem to be worth the trouble when there are so many other quality ingredients such as the various forms of vitamins A and C that have been proven to better assist in the stimulation and formation of collagen.