Composition for improving sunscreen performance

Abstract

Film-forming compositions capable of improving the effectiveness of sunscreen formulations, especially those comprising the inorganic sunscreen ZnO or TiO2. The composition according to the invention comprises a specific combination of an acrylate / VA copolymer and an acrylate copolymer in a cosmetically acceptable matrix or delivery vehicle. These copolymers may be incorporated into a composition comprising a physical sunscreen, or they may be incorporated into a priming cream composition that is applied directly to the skin and then a composition comprising a physical sunscreen.

Description

TECHNICAL FIELD

[0001] The present invention is in the field of photoprotective compositions. More particularly, the present invention relates to film-forming compositions that improve the performance of sunscreen formulations. PRIOR ART

[0002] The spectrum of ultraviolet radiation emitted by the sun has wavelengths between about 100 nm and 400 nm. The portion of the spectrum between about 290 nm and 320 nm is referred to as UV-B (UVB), while the portion between about 320 nm and 400 nm is referred to as UV-A (UVA). The portion of the UVA spectrum between 340 nm and 400 nm is further designated as UVAI (long-wave UVA). Most, but not all, of the UV-B radiation from the sun is absorbed by the ozone layer of the earth, while UV-A radiation is not significantly absorbed in the atmosphere. Both UV-A and UV-B are known to have deleterious effects on human skin.

[0003] UVB rays have higher energy than UVA rays and are much more effective at producing sunburn and cellular damage, including DNA damage. UVA rays are not as effective as UVB rays at producing sunburn. However, UVA makes up a large portion of UV radiation and penetrates much deeper into the skin than UVB. Thus, UVA rays have the potential to promote the formation of reactive oxygen species (ROS) and thereby cause oxidative damage to skin pigment cells. UVA rays also contribute to the formation of photoaging and DNA damage, although to a lesser extent than UVB.

[0004] Sunscreen products are applied to human skin to protect the skin from harmful UVA and UVB rays in sunlight by filtering or blocking them. The active ingredients in sunscreen products are broadly divided into two categories: chemical sunscreens and physical sunscreens. Chemical sunscreens absorb ultraviolet radiation and convert it into less dangerous types of energy organic molecules. Chemical sunscreens can be further classified according to whether their primary action is against the UV-A or UV-B portion of the spectrum. In the United States, the following UV-A absorbers have historically been common: avobenzone, dioxybenzone, ecamsule, meradimate, oxybenzone, and sulisobenzone. Chemical UV-B absorbers include: cinoxate, ensulizole, homosalate, octinoxate, octisalate, octocrylene PABA, padimate O, and trolamine salicylate. The second category of sunscreen is physical sunscreens. These are inorganic molecules, such as titanium dioxide and zinc oxide, that absorb, reflect, and scatter light, changing its wavelength in the process. Titanium dioxide (Ti02) is a moderate strength UVB absorber and a somewhat less good UVA absorber. On the other hand, zinc oxide (ZnO) is considered effective against both UVA and UVB rays, but less so against UVB.

[0005] In recent years, there has been a growing need to better understand the overall safety of some sunscreen active agents. As a result, some chemical sunscreen active ingredients have fallen out of favor and their use has been reduced or eliminated. On the other hand, the physical sunscreen active materials titanium dioxide and zinc oxide are still considered overall safe and effective, and these materials have become the first choice for sunscreen actives. However, physical sunscreens always have drawbacks. These drawbacks include formulation stability issues. Physical sunscreens are relatively dense. Over time, physical sunscreens tend to settle out of fluid compositions, which makes their application inconsistent and the sunscreen protection they provide variable. To ensure that consumers get the SPF level claimed on the label, sunscreen product manufacturers tend to over- dose their products with sunscreen. This can be expensive and unattractive, resulting in a chalky appearance and a heavy, uncomfortable skin feel.

[0006] Commonly owned application US 17 / 535,556 discloses a water-resistant sunscreen composition comprising one or more sunscreen active materials and at least two film formers. The film formers required are an acrylates copolymer and xanthan gum in a ratio of about 15: 1 to about 1 : 1. In the following commonly owned applications US 15 / 632,903 (now US Patent 1,1103,439), US 15 / 906,372 (now US Patent 1,0813,874), US 17 / 029,147, US 17 / 176,527, US 16 / 816,995, US 16 / 197,858, US 16 / 381,806 (now US Patent 1,0507,175), US 16 / 267,441 (now US Patent 1,0980,717), US 17 / 189,768, US 16 / 827,876 (now US Patent 1,1129,788), and US 17 / 806,294 (all incorporated by reference in their entirety herein), the applicants disclose specific combinations of acrylates / VA copolymers and acrylates copolymers in aqueous bases, and various useful properties of these combinations, depending on the application and the presence of certain other ingredients. When applied to a skin surface, these compositions, despite being water-based, dry to a transparent, flexible, and comfortable film, and are resistant to moisture breakdown as long as the water temperature is below a certain minimum value.

[0007] More specifically, US application 17 / 806,294 discloses a topical film-forming composition capable of effectively delivering active ingredients to keratinous surfaces in a time-released manner. The composition comprises a film former comprising an acrylates / VA copolymer and an acrylates copolymer in a weight ratio of 10: 1 to 30: 1, and a combination of propane- 1,3 diol and glycerin. The combined weight of the acrylates / VA copolymer and the acrylates copolymer comprises 20% to 60% of the total composition weight. It is reported that the pore size formed in the dried film can be controlled or fine-tuned.

[0008] U.S. Patent 1,0980,717 discloses ethanol-reduced perfume compositions that retain fragrance integrity, the compositions comprising 4.5% to 18.5% by weight of an acrylates / VA copolymer, 0.25% to 1.0% by weight of an acrylate copolymer in an aqueous base, and one or more acrylates / VA copolymers capable of plasticization in the aqueous phase, and a material that alters the resulting film porosity upon drying. It is reported that generally, more plasticizer in the aqueous phase tends to increase the size of surface pores formed in the acrylates / VA copolymer-acrylate copolymer film. Controlling this pore size is key to controlling fragrance release over time and to retaining the integrity of the fragrance ingredients in the composition. It is reported that particularly good results are obtained when the weight ratio of acrylates / VA copolymer to acrylate copolymer is in the range of 10:1 to 30:1.

[0009] None of the above references disclose film-forming compositions that are capable of improving the effectiveness of sunscreen formulations, especially those containing the inorganic sunscreen agents ZnO or TiO2. There remains a need for improved photoprotective sunscreen compositions. SUMMARY

[0010] The compositions according to the present application comprise a specific combination of acrylates / VA copolymer and acrylate copolymer in a cosmetically acceptable base or delivery vehicle. These copolymers can be incorporated into compositions containing physical sunscreens such as titanium dioxide and zinc oxide. Alternatively, they can be incorporated into a primer composition that is applied directly to the skin, followed by application of a composition containing a physical sunscreen.

[0011] Upon application to the skin, the acrylates / VA copolymer and acrylate copolymer dry into a film in the form of a network of pores of preferred size and preferred Young's modulus. The compositions of the present application significantly improve the SPF in the critical range of about 200 nm to about 420 nm when used as described herein. The compositions according to the present application can be sprayed with a conventional cosmetic pump sprayer or can not be sprayable.

[0012] Except in the operating and comparative examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, quantities of materials, physical properties of materials, or use are to be understood as modified by the word "about". Unless otherwise indicated, all amounts are expressed in percent by weight of the final composition.

[0013] Throughout this description, "film-former" and the like refer to a polymer that, for example, leaves a film on a substrate after the solvent accompanying the film-former evaporates, absorbs into the substrate to which the polymer is applied, and / or dissipates on the substrate.

[0014] "Comprising" and like terms are meant to encompass the items listed thereafter as possibilities.

[0015] A "sunscreen product" contains any ingredient capable of absorbing, reflecting, or scattering UV rays, which product is intended to be placed on the surface of human skin with the purpose of preventing UV-induced erythema (sunburn) and other UV-induced skin damage. Sunscreen active ingredients are primarily of two classes: organic and inorganic.

[0016] The "minimal erythema dose" (MED) is the minimum UV dose that produces perceptible skin redness (erythema) with well-defined borders 16 to 24 hours after UV exposure.

[0017] The "sun protection factor" (SPF) is a relative measure of the ability of a sunscreen product to protect skin from UV-induced erythema (sunburn). The SPF test measures the amount of UV radiation exposure required to cause sunburn when a person is using sunscreen compared to the amount of UV exposure required to cause sunburn when the person is not using sunscreen. SPF is related to MED because the SPF of a sunscreen product applied to the skin increases the MED of the individual.

[0018] The "critical wavelength" (CW) is the wavelength below which 90% of the total sunscreen UV absorption occurs. The higher the CW, the greater the range of protection across the UV spectrum (290 to 400 nm).

[0019] A spectrophotometer is an instrument that measures the light transmission properties of a material as a function of wavelength.

[0020] Acrylates / VA copolymer

[0021] The first main ingredient of the present invention is an acrylates / VA copolymer with monomers of vinyl acetate and 2-ethylhexyl prop-2-enoate; CAS number 25067-02-1, C 14 H 22 O6. For more detailed information, see PubChem Compound Database; CID=168269.

[0022]

[0023] In cosmetics, this adhesive material is often used as an adhesive, film former, glue, and / or hair fixative. When effectively utilized in aqueous cosmetic systems, the aforementioned acrylates / VA copolymer can impart a film on the skin or hair. The pure acrylates / VA copolymer film is characterized by temperature dependence, such that a water rinse of about 38°C or higher will degrade the film and enable its removal from the surface, while remaining intact at or below normal skin temperature (i.e., 36.5°C to 37.5°C).

[0024] The composition according to some preferred embodiments of the present application comprises from about 5% to 30% of the acrylate / VA copolymer, for example from 10% to 20%, preferably about 10%, by total weight of the composition.

[0025] The acrylate / VA copolymer described above is commercially available, for example, Vinysol 2140L from Daido Chemical Corp. Vinysol 2140L is a 46.6% aqueous mixture of acrylate / VA polymer. Thus, when Vinysol 2140L is used, to achieve the concentration of the acrylate / VA copolymer described above, the concentration of Vinysol 2140L should be from about 10.7% to 64.4%, for example, 21.5% to 42.9%, preferably about 21.5%, by total weight of the composition. Vinysol 2140L is reported to have a pH of 4.5, a viscosity of 2,000 mPa-s, a calculated glass transition temperature (Tg) of -9°C, while the film exhibits an elongation at break of 1,200% and a break strength of 1.2 MPa (when extended to 0.1 mm thickness). The acrylate / VA copolymer is, in itself, slightly too rigid for consumer acceptance. g ) for consumer acceptance.

[0026] Acrylates copolymer

[0027] To address the problem of high rigidity, the acrylate / VA copolymer is combined with an acrylate polymer having a lower T g than the acrylate / VA polymer. Generally, a lower T g provides greater flexibility to the resulting film. It also increases the drying time of the film to a useful degree. Of course, a film-forming composition that dries too fast or too slow is not commercially viable. In the present application, the appropriate drying time of the dried film and the appropriate amount of flexibility are provided by the second major ingredient: an acrylate copolymer whose monomers are ethyl prop-2-enoate; methyl 2-methylprop-2-enoate; 2-methylprop-2-enoic acid; CAS Number 25133-97-5 (C 14 H 22 O6).

[0028]

[0029] For further details, see PubChem Compound Database; CID=168299. The acrylate copolymer has a wide variety of uses in various types of cosmetic formulations, including as a film-forming agent, a hair fixative, an adhesive and suspending agent, a tackifier, an anti-static agent, and a glue.

[0030] In the present application, the useful concentration of the acrylate copolymer is from 0.25% to 1.5%, for example from 0.50% to 1.0%, preferably about 0.5%, based on the total weight of the composition. The acrylate copolymer described above is commercially available, for example, Daitosol 5000AD from Daito Kasei Kogyo Co. Daitosol 5000AD is a 50% aqueous mixture of the acrylate copolymer. Therefore, to achieve the concentration of the acrylate copolymer described above, the concentration of Daitosol 5000AD should be from about 0.5% to 3%, for example from 1.0% to 2.0%, preferably about 1.0%, based on the total weight of the composition. It is reported that the pH of Daitosol 5000AD is from 5.5 to 7.5, the viscosity is from 50 mPa-s to 100 mPa-s, the glass transition temperature (T g ) is -14°C. Based on this, it can be said that the ratio of the weight of the acrylate / VA copolymer to the weight of the acrylate copolymer is in the range of 3.3: 1 to 120: 1. Preferably, the ratio is from 10: 1 to 40: 1, more preferably from 10: 1 to 30: 1, even more preferably from 18: 1 to 20: 1.

[0031] Physical sunscreen

[0032] Some preferred embodiments of the present application comprise one or more physical sunscreens, such as Ti02and ZnO. Some preferred embodiments of the present application comprise from about 1% to about 20% of all physical sunscreens, based on the total weight of the composition.

[0033] Water

[0034] The composition of the present application is aqueous and generally can comprise from about 20% to about 70% of water, based on the weight of the total composition. This amount of water is from all sources, such as the amount of water in Vinysol 2140L and Daitosol 5000AD.

[0035] Pore matrix

[0036] As noted above, after drying on a substrate, the compositions of the present application will form a film comprising a multi-layered porous matrix. It has been noted that compositions having an average pore size of about 1 to 5 μm (e.g., 1.5 to 3 μm) can be used to improve sunscreen performance. In addition, individual pores as small as 0.3 μm (300 nm) have also been observed. Thus, the smaller pores in the matrix overlap in size with a portion of the UVA wavelength range (320 to 400 nm) and the UVB wavelength range (290 to 320 nm), and this can explain at least some of the ability of the compositions of the present application to provide improved protection from ultraviolet light. In addition, as the composition dries, the physical sunscreen particles collect in the pores of the film, which results in a multi-layered and regular distribution of the TiO2and / or ZnO. This is an improvement over conventional physical sunscreen compositions, where the relatively dense sunscreen agents tend to settle in the composition, resulting in inconsistent sun protection. As an added benefit, since the physical sunscreen particles (i.e., TiO2and / or ZnO) collect in the pores of the dried film, there is less chance that the sunscreen particles will penetrate the skin.

[0037] Plasticizer

[0038] The compositions of the present application can comprise one or more plasticizers in the specified amounts. These materials provide several benefits, such as increasing the sprayability of the wet composition. Without a plasticizer, it is difficult, if not impossible, to spray the composition from a mechanical pump-type sprayer of the type commonly used in the cosmetic industry. At best, a narrow stream of product is produced that is poorly atomized upon impact with the atmosphere. This is unacceptable for a product intended to cover a relatively large area of film by spraying.

[0039] As another benefit, the plasticizers can also be used to adjust the Young's modulus of the film as it dries on the skin. The Young's modulus is a measure of the stiffness of a material under tension or compression. A lower Young's modulus means a lower stiffness of the material. The Young's modulus of human skin generally varies between about 0.42 and 0.85 MPa. A film formed on the skin that has a Young's modulus lower than that of the skin (i.e., when the film is more flexible than the skin) feels more comfortable. Preferred compositions of the present application produce a film having a Young's modulus lower than that of the skin. More preferred compositions of the present application produce a film having a Young's modulus less than half that of the skin. Even more preferred is when the Young's modulus of the film is less than one-third that of the skin. And these are all achievable with the present application.

[0040] Plasticizers can also be used to some extent to adjust the pore size in the dried film on the skin and fine tune the UV protection benefits. Generally, more plasticizer tends to increase pore size, so its use should be limited so as not to lose too much of the sunscreen improvement. For these reasons, some embodiments of the present application include one or more of butylene glycol, propylene glycol, and glycerin. Preferred compositions of the present application include from 1% to 5% of butylene glycol, propylene glycol, glycerin, or any combination thereof, based on the total weight of the composition.

[0041] Surfactant and emulsifier

[0042] One or more surfactants or emulsifiers can also be used to adjust the surface tension. As noted above, the compositions of the present application generally include from about 0.5% to about 2% water, by weight of the total composition. Some preferred embodiments of the present application are single aqueous phase compositions and have little or no oil or silicone. In other preferred embodiments, the compositions are lightly emulsified oil-in-water emulsions. Emulsion embodiments are useful when the composition includes a fragrance oil, or when the composition is to be used to deliver at least one oil-soluble active, such as vitamin E acetate, to the keratinous surface. However, one or more surfactants or emulsifiers can also be used in the present application to lower the surface tension and increase the sprayability of the spray-on film-forming composition. Generally, increasing the level of surfactant or emulsifier will lower the surface tension of the film-forming composition. Whether used to adjust the surface tension or to emulsify oil-soluble ingredients, the HLB of the one or more surfactants or emulsifiers should be between 8 and 12 and comprise no more than 2% of the total composition, generally between 0.01% and 2% of the total composition.

[0043] Hydrophobic material

[0044] The film-forming composition of the present application is in a first or hydrophilic state prior to application to the keratinous surface. The ability to formulate with water-soluble ingredients in this first state is advantageous. To maintain sufficient hydrophilicity in this first state, the use of hydrophobic materials should be limited to less than about 5%, such as 0.001% to 5%, based on the total weight of the composition; preferably less than 2%, more preferably less than about 0.25%. Materials that are partially hydrophilic and partially hydrophobic can exceed these limits based on the performance of the final composition. In some embodiments of the present application, it is preferred if the composition does not include a hydrophobic ingredient, such as a hydrophobic oil or wax. Oils are organic substances that are liquid at ambient temperature, such as esters, triglycerides, hydrocarbons, and silicones. One typical wax used in cosmetic compositions is carnauba wax. In some embodiments of the present application, it is most preferred if the composition does not contain a hydrophobic oil or wax.

[0045] Polyurethane

[0046] Polyurethanes tend to make the composition very rigid and inhibit pore formation. Thus, the film-forming composition of the present application comprises no more than 0.5%, for example, from 0.0001% to 0.5%, of a polyurethane. More preferably, the composition of the present application does not comprise a polyurethane.

[0047] Various ingredients

[0048] Various ingredients can be included in the film-forming composition to fine-tune the consumer experience or to improve the performance of the composition and adjacent cosmetic or skin care formulations. For example, alcohols can be used to accelerate drying after application to the skin. Alcohols can be useful in amounts up to 5%. The film-forming composition can also include preservatives and antioxidants, generally up to about 2% by weight of the composition. Thickening agents, viscosity-reducing agents, and / or pH adjusting agents such as caustic soda can be used as needed to produce a consumer-acceptable product, generally at levels below 1% by weight of the composition. At these levels, the specified ingredients above do not appear to adversely affect the useful attributes of the film-forming composition.

[0049] The composition of the present application can or can not include pigments. When pigments are present, the preferred composition will include no more than 1%, for example, from 0.001% to 1%, of pigments in total.

[0050] Active ingredients can be incorporated into the water phase or the oil phase, if any. Examples of hydrophilic (water-soluble) actives include: algae extract, Alpinia speciosa leaf extract, Alteromonas ferment extract, ascorbyl glucoside (AA2G), Citrullus lanatus fruit extract, Crataegus monogyna flower extract, hyaluronic acid, hydrolyzed yeast protein, Lactobacillus ferment, Matricaria (Chamomilla) recutita extract, Lathyrus (Lens culinaris) fruit extract, Paeonia (Paeonia suffruticosa) root extract, panthenol, Pyrus malus fruit extract, and Saccharum extract. Each individual hydrophilic active is generally incorporated at no more than 5.0%, for example, from 0.0001% to 5%, by weight of the composition. Examples of hydrophobic (oil-soluble) actives include Anthemis nobilis oil, bht (butylated hydroxytoluene), caffeine, cocoa (coconut) oil, salicylic acid, tetrahexyldecyl ascorbate, and tocopheryl acetate. Each individual hydrophobic active is generally incorporated at no more than 1%, for example, from 0.0001% to 1%, by weight of the composition. DETAILED DESCRIPTION

[0051] Absorption analysis 1

[0052] The composition according to the present invention comprises a specific combination of acrylate / VA copolymer, acrylate copolymer and physical sunscreen in a cosmetically acceptable aqueous matrix. Upon drying, the acrylate / VA copolymer and acrylate copolymer form a film comprising a multi-layer porous matrix. The ability of this film to significantly increase SPF in the range of about 200 nm to about 420 nm can be first demonstrated by determining how much light is absorbed by the matrix. A 20:1 mixture of acrylate / VA copolymer and acrylate copolymer is spread onto a PMMA petri dish and allowed to dry into a film approximately 1.5 mm thick. A quartz halogen lamp (Britek Halo Flood 800 / 650PS) at a distance of 12 inches serves as a source of visible and UVA radiation. At a distance of 4 inches, A 95-0313-01 Model: MRL-58 with a UVB bulb was used as the source of UVB radiation. Absorbance was measured using a Solar Light Model: PMA2100 Dual Input Data Logging Radiometer with a UVA Detector PMA2110, a UVB Detector PMA2106, and a Photopic Detector PMA2130.

[0053] The light intensity (W / m 2 ): light passing through air only; light passing through air and a clean PMMA Petri dish; light passing through air, a dry film test sample, and a PMMA dish.

[0054]

[0055] The results clearly show that the dried polymer membrane is much better at filtering UV-A and UV-B radiation than visible light. Therefore, the polymer membrane is selective with respect to UV-A and UV-B absorbance. It is suspected that this selectivity is related to the size of the pores in the polymer matrix.

[0056] Absorption analysis 2

[0057] Next, the absorbance of UVA and UVB radiation was measured by a fully formulated physical sunscreen product incorporating a combination of acrylates / VA copolymer and acrylates copolymer. The analysis utilized two control samples and one test sample. A base formula containing 10% zinc oxide was used as control sample 1. Control sample 1 can be considered a conventional physical sunscreen product. The test sample consisted of a base formula (conventional sunscreen product) plus two polymers, acrylates / VA copolymer and acrylates copolymer, in a ratio of 18.6:1. Control sample 2 consisted of a base formula with zinc oxide removed, and two polymers, acrylates / VA copolymer and acrylates copolymer, added in a ratio of 18.6:1. The test and control samples are shown in the table below.

[0058]

[0059] 1 Acryloyldimethylammonium taurate / VP copolymer

[0060] 2 Caprylyl glycol / Phenoxyethanol / Hexylene glycol

[0061] 3 Crosslinked homopolymer of polyacrylic acid (thickening agent)

[0062] Procedure

[0063] The test is based on the evaluation of the UV transmittance through a thin film of the sample product. For each test sample, a layer of homogeneous product is applied to a substrate of roughened polymethyl methacrylate (PMMA) (Helioplate® TM HD6 from HelioScreen, Cirey, France). The roughness of the substrate is 5 μιη to simulate the skin topography. 32.5 mg of product is applied to the substrate at a concentration of 1.3 mg / cm 2 The product is allowed to air dry for at least 15 minutes, after which the UV absorption curve is generated and the raw data are analyzed using a UV spectrophotometer (Optometrics, Corp.) using SPF-290S. Four measurements are taken for each sample and averaged together.

[0064] Results

[0065]

[0066] Discussion of results

[0067] The U.S. Food and Drug Administration (FDA) requires that for a product to claim "broad spectrum" protection, the critical wavelength must be > 370 nm. The "critical wavelength" in vitro is the wavelength below which 90% of the area under the UV absorption curve lies. Generally, the higher the critical wavelength, the greater the range of protection across the UV spectrum (290 nm to 400 nm). All three samples met the critical wavelength requirement.

[0068] The FDA further requires that broad spectrum sunscreen products exhibit a UVA1 / UV absorption ratio of > 0.7. The test sample (zinc plus polymer) and control sample 1 (zinc only) met these broad spectrum requirements. The UV absorption curves show that the test sample and control sample 1 exhibit very little decrease in amplitude (absorption) below 370 nm wavelength, then a sharp drop to 400 nm.

[0069] In contrast, Control Sample 2 (polymer, but no ZnO) exhibited a UVA1 / UV ratio of 0.66. The UV absorption curve showed a significant and steady decrease in amplitude (absorbance) from 290 nm to 370 nm, and maintained a low amplitude (absorbance) to 400 nm. This decrease brought the UVA1 / UV ratio below 0.7, beyond the FDA's requirement for broad-spectrum protection.

[0070] The SPF value is directly related to the area under the absorbance curve for the UVB portion (290 nm to 320 nm); the greater the area, the greater the SPF value. Note that for Control Sample 1 (a conventional sunscreen product with zinc), the area under the absorbance curve for the UVB portion was 25.30. For Control Sample 2 (polymer, but no zinc), the area under the absorbance curve for the UVB portion was only 1.21. Thus, completely unexpectedly, the test sample (a conventional sunscreen product with the addition of a polymer) exhibited an area under the absorbance curve for the UVB portion of 37.84, far beyond what would be expected from an additive effect. In fact, the addition of the acrylates / VA copolymer and the acrylates copolymer to a composition containing ZnO synergistically increased the area under the absorbance curve for the UV-B portion (and thus synergistically increased the SPF) without the addition of more ZnO. Moreover, while Control Sample 2 (polymer, but no ZnO) did not meet the definition of "broad spectrum," the test sample with ZnO and both polymers did, due to the observed synergistic effect.

[0071] Absorption analysis 3

[0072] As noted above, the compositions within the scope of the present application can also be used as a primer, applied first to the skin, and a separate sunscreen composition applied on top. To demonstrate the effectiveness of this approach, a primer composition was developed that did not have a sunscreen, the primer composition comprising the acrylates / VA copolymer and the acrylates copolymer (see table below). Next, a test sunscreen composition was selected to be applied on top of the primer composition after the primer composition had dried on the substrate. For this purpose, Bobbie Brown TM Clear, hold makeup liquid foundation SPF 15, comprising 0.61% titanium dioxide (TiO2) and the chemical sunscreen, octinoxate (3%). The area under the absorbance curve for the UV-B portion of the primer composition and the test sunscreen composition were measured according to the procedure detailed above.

[0073] Ingredients Primer composition Water q.s. Acrylates / VA copolymer 18.63 HDI / PPG / polycaprolactone crosspolymer 4.90 Ethanol 3.00 Propylene glycol 3.00 Acrylates copolymer 1.00 Glycerin 1.00 Phenoxyethanol 0.89 Xanthan gum 0.40 Silica 0.10 Polyquaternium-6 0.06 Sodium dehydroacetate 0.04 Disodium EDTA 0.04 Sodium hyaluronate 0.01 Laureth-20 0.01

[0074] Results

[0075]

[0076] Discussion of results

[0077] For the commercially available SPF 15 product, the area under the absorbance curve for the UVB portion was 59.60 when applied directly to the PMMA plate. However, when the primer composition according to the application, which has very little sunscreen efficacy, was first applied to the PMMA plate, then the SPF 15 product was applied, the area under the absorbance curve for the UVB portion increased significantly to 92.95, or by 56%. This means that the estimated SPF increase was slightly more than 50%.

[0078] It was also noted that the critical wavelength of the primer / sunscreen product combination decreased slightly, but was still well above the 370 nm required for a "broad spectrum" claim as required by the U.S. Food and Drug Administration. Thus, the composition comprising the specific combination of acrylates / VA copolymer and acrylates copolymer was effective in increasing the SPF of a sunscreen product comprising physical sunscreens when used as a primer.

[0079] Conclusion

[0080] It was not initially known that the specific combination of acrylates / VA copolymer and acrylates copolymer could be used to synergistically increase the effectiveness of compositions comprising physical sunscreens. It was further unclear whether it would be possible to incorporate the acrylates / VA copolymer and acrylates copolymer into sunscreen products in a commercially viable manner to produce a thermodynamically stable composition that felt comfortable on the skin. It was also unclear whether the specific combination of acrylates / VA copolymer and acrylates copolymer could be used in a primer composition to increase the effectiveness of sunscreen compositions without increasing the level of physical sunscreens in the product.

Claims

1. A film-forming composition comprising, based on the total weight of the composition: 5.0% to 30% acrylates / VA copolymer; Acrylate copolymers, wherein: The ratio of acrylate / VA copolymer to acrylate copolymer is between 3.3:1 and 120:1; 20% to 70% water; 1% to 20% physical sunscreens, and Wherein, when the film-forming composition is applied to a substrate and the film-forming composition is allowed to dry, the dried film will have an average porosity between 1 μm and 5 μm.

2. The composition of claim 1, wherein the physical sunscreen is titanium dioxide, zinc oxide, or a combination thereof.

3. The composition of claim 1 , wherein the ratio of the acrylates / VA copolymer to the acrylates copolymer is between 10:1 and 40:

1.

4. The composition of claim 3, wherein the ratio of the acrylate / VA copolymer to the acrylate copolymer is between 10:1 and 30:

1.

5. The composition of claim 4, wherein the ratio of the acrylates / VA copolymer to the acrylates copolymer is between 18:1 and 20:

1.

6. A sun protection treatment regimen comprising the following steps: a. Applying directly to the skin a film-forming primer composition comprising, by weight of the total composition: 5.0% to 30% acrylates / VA copolymer; Acrylate copolymer, wherein: the ratio of the acrylate / VA copolymer to the acrylate copolymer is between 3.3:1 and 120:1; 20% to 70% water; and No physical or chemical sunscreens; wherein, when the primer composition is allowed to dry, the dried film has an average porosity between 1 μm and 5 μm; b. allowing the primer composition to dry; c. Apply the sunscreen composition on top of the dried primer composition.

7. The composition of claim 3, wherein the sunscreen composition comprises one or more physical sunscreens.

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