@Perry I do not follow the party line about HAs since I am skeptical until proof of adequate scientific quality is provided.
I do not believe that topical HAs do anything other than sit on top of the SC and provide and/or accumulate water from either the product itself which contains water or the atmosphere.
This may not be a good thing for healthy skin since it leads to a disruption of an SC barrier integrity. Why disrupt the SC barrier with water? Skin, like hair, needs oil and not water unless the intent is disrupt the natural oil-based barrier.
I have a different idea-to use the HAs to grab water from the atmosphere and have the HAs remove water before it disrupts the barrier-use HAs as a protectant from water-so why would I want to provide water with a HA ingredient that has been saturated with water? Once HAs are saturated with water, they are more harmful than good-unless your intent is to damage the natural barrier.
If you believe that the HAs penetrate the SC barrier and bring with it water, which I do not, and HAs enter the dermis, which I do not, then the HAs would go into the skin fully saturated with water, damage the barrier and produce leaky skin followed by a cascade of water-infused events with water going in and out of the skin affecting permeability.
However, it is my view that HAs only function from outside the skin by grabbing water and not allowing atmospheric water to harm the SC -if not already fully saturated with water.
So- why add water to a HA formulation. It defeats the purpose of its purported activity!