According to this patent, a new gel matrix based cross-linked HA can bind unusually high capacities of water; higher than other natural and synthetic polymers. It also can "cage" and deliver actives to skin in a prolonged manner.
Cross-linked hyaluronic acid for topical cosmetic and therapeutic applications
U.S. Patent 9345778
Publication date: May 24, 2016
Assignee: LuroMed LLC
This patent discloses compositions based on cross-linked hyaluronic acid gels, especially vinyl sulfone cross-linked hyaluronic acid (known as hylan B gel), for topical cosmetic and dermatological formulas.
According to the inventors, the hylan B gel provides prolonged delivery of incorporated substances to the skin surface by imparting a hydrated, substantive and skin-compatible film. The gel acts as a hydrated molecular "cage" (described in U.S. Pat. No. 4,636,524) into which substances may be incorporated. Typically, the composition contains an active ingredient at 10-20% w/w of the total composition.
The gel may be in equilibrium or non-equilibrium form. In non-equilibrium form, the gel is not fully swollen; in equilibrium form, it is and it cannot swell further. The gel matrix has an unusually high capacity to bind water, to a greater degree than other natural and synthetic polymers.
Patent accessed May 24, 2016.