Enhanced efficiency of sunscreen compositions
Certain aspects of the invention relate to compositions comprising UV blocking agents, a film forming polymer containing acid groups and a neutralizing agent. Such compositions have an increased SPF due to neutralization of at least a portion of the acid groups of the film forming agent by the neutralizing agent. The invention also discloses methods for increasing SPF of a composition as well as methods for using the novel composition.
1. A sprayable anhydrous sunscreen composition comprising at least one UV absorbing active ingredient, a film forming polymer containing a plurality of acid groups, and a volatile solvent, wherein the polymer is present in an amount greater than 1% by weight of the composition and wherein at least a portion of the acid groups have been neutralized with a cosmetically acceptable amine-based neutralizing agent and the SPF of the sprayable anhydrous sunscreen composition is greater than 125% of a composition containing un-neutralized film forming polymer,
wherein said amine-based neutralizing agent is PEG-15 cocamine, said film forming polymer is Acrylates/Octylacrylamide Copolymer, and wherein the solvent is selected from ethanol, isopropanol, methanol or acetone.
2. The composition of claim 1 , wherein from about 5 to about 100 percent of the plurality of acid groups of the film forming polymer are neutralized by said amine-based neutralizing agent.
3. The composition of claim 1 , wherein from about 5 to about 50 percent of the plurality of acid groups of the film forming polymer are neutralized by said amine-based neutralizing agent.
4. The composition of claim 1 , wherein from about 5 to about 25 percent of the plurality of acid groups of the film forming polymer are neutralized by said amine-based neutralizing agent.
5. The composition according to claim 1 , further comprising an inorganic pigment selected from titanium dioxide, zinc oxide, iron oxide, zirconium oxide, cerium oxide or mixtures thereof.
6. A method for reducing the deleterious effects of UV radiation that contacts a surface which comprises applying to the surface the composition of claim 1 .
7. A method for reducing the occurrence of erythema on a subject due to exposure to UV radiation which comprises applying the composition of claim 1 to the subject prior to exposure to UV radiation.
8. A method for reducing photoaging of the skin of a subject due to exposure to UV radiation which comprises applying the composition of claim 1 to the subject prior to exposure to UV radiation.
9. A method for reducing the occurrence of phototoxic or photoallergic reactions in a subject due to exposure to UV radiation which comprises applying the composition of claim 1 to the subject prior to exposure to UV radiation.