A delivery system is ingredients in the formula that assist in the delivery of other ingredients in to the skin.
Some examples are liposomes, nano technology, micro capsules - encapsulation, micro sponge technology, emulsions, carrier oils, etc. think of a tiny balloon you can fill with active ingredients that gets the ingredients past the lipid barrier.
Because the skin is so very efficient at keeping things out with the lipid barrier, advanced skin care products encapsulate ingredients to get them down a little bit further.
Besides delivery systems and vehicles, cell communicating ingredients actually do a great deal of work in the skin too, and are particularly needed to effect the skin at the dermal level. How they work is, they send chemical messages to cells, which pass the message along to the target cells, and tell them to behave a certain way. For example activate hyaluronic acid production etc.
The technology today is getting even more complex with ingredients affecting gene expression in the skin. The products I work with use ingredients to switch on and off certain genes, to create the desired effect in the skin. Not long ago a company in UK identified genes responsible for greying hair (loss of pigment) and developed and ingredient they apply with shampoos and conditioners that "switch " the genes back on that generate melanin production in hair. So as you use their shampoo and conditioner you no longer grow grey hair.
That is where the science is heading in skin care. A delivery system (ingredients that deliver the active ingredients where you want them) will also be an important part of these advanced formulas. Here is an excellent read on delivery systems:
Follow me on