Patent Pick: A 'Swell' Sunscreen Stabilizer

According to P&G inventors, there is always a need for compositions that improve the look and feel of personal care products and are stabler over time; especially in the case of sunscreens. Furthermore, consumers continually seek novel, longer-lasting compositions.

In response, super-absorbent polymers was developed to provide better stability in sunscreens than conventional thickener systems. The products incorporating them also are less shiny, which when applied to human skin, provides a less-reflective coating and makes skin appear smoother.

These polymers described in this patent have a high capacity for absorbing and retaining water and aqueous fluids. After absorbing liquids, the particles of the polymer impregnated with aqueous fluid remain insoluble in the aqueous fluid, thus retaining their separated particulate state. Further details are disclosed in the following patent.

Super-absorbent polymers and sunscreens actives for skin care
U.S. Pat Application 20170056314 
Assignee: The Procter & Gamble Company
Publication date: March 2, 2017

Here, a skin care composition is described having ~0.01% to 5.00% w/w of a super-absorbent polymer. Said polymer is a sodium polyacrylate, sodium polyacrylate starch, sodium acrylates crosspolymer-2 or mixtures of these; and a portion of the polymer comprises a grafted starch material. The polymer particles have an average size in the range of ~5 μ to 30 μ, and the individual particles in their dry or unswollen condition are substantially non-spherical, flat, platelet or elongated in shape.

These particles have an absorption capacity of at least ~1,000 times their initial dry or unswollen volume. Additionally, the described skin care composition contains ~0.01% to 10.00% of a dry powder that is starch or silicone based and coated with a silicone-based material. Also included is a UV active.