Sunscreen compositions containing visible light protectants and methods of use

Abstract

Provided herein are methods for reducing or preventing sunburn caused by visible light and ultraviolet radiation in a subject, comprising topically applying to the subject a sunscreen composition comprising at least one inorganic UV filtering agent selected from zinc oxide or titanium dioxide, at least one inorganic pigment selected from iron oxides, and at least two visible light protection agents, including barium sulfate and mica, wherein the at least two visible light protection agents are present in amounts effective to reduce or prevent sunburn caused by visible light. Also provided herein are sunscreen compositions and methods for increasing the visible light protection factor of sunscreen compositions.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of and relies on the filing date of U.S. Provisional Patent Application No. 63 / 396,769, filed August 10, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] This paper discloses a topical sun protection composition, comprising at least one inorganic UV filter, at least one inorganic pigment, and a combination of at least two visible light protection agents.This composition can be used to protect against both visible light-induced erythema and ultraviolet radiation-induced erythema. [Background technology]

[0003] The electromagnetic spectrum is the spectrum that includes the range of frequencies of electromagnetic radiation and their associated wavelengths, from the shortest wavelengths of radio waves to the highest wavelengths of gamma ionizing radiation. Starting with the lowest frequency waves, the spectrum is divided into the following bands: radio waves, microwaves, infrared, visible light, ultraviolet light, X-rays, and gamma rays. Initially, only visible light, with wavelengths corresponding to the range of approximately 400 nm to approximately 700 nm, was known to exist. However, in 1801, Johann Ritter discovered that the UV portion of the electromagnetic spectrum, with wavelengths corresponding to approximately 10 nm to approximately 400 nm, is photochemically and photobiologically active. The most common source of UV light is the sun, and it is this UV radiation that causes what is commonly referred to as "sun dermatitis" or "erythema." The UV band of the electromagnetic spectrum itself includes three subspectral bands: UVA (approximately 320-400 nm), UVB (approximately 280-320 nm), and UVC (approximately 100-280 nm).

[0004] Photodermatitis is a reddening of the skin resulting from prolonged exposure to the sun. The severity of photodermatitis can range from mild to severe based on several factors, including the length of exposure, the intensity of exposure, and the individual's skin type, with whiter skin being at greater risk. Photodermatitis is a well-known risk factor for skin cancer.

[0005] The Fitzpatrick skin typing system, which can predict a person's tendency to burn or tan when exposed to sunlight, is a commonly used system (see Non-Patent Document 1). In the Fitzpatrick skin typing system, skin can be classified into one of six skin types: Type I skin is fair skin and typically burns without tanning, while Type II skin usually burns or tans less than average or with difficulty. Type III skin tans to an average degree with minor burns, and Type IV skin tans easily but rarely burns. Type V and Type VI refer to brown and black skin, respectively, and rarely or never burn. The Fitzpatrick skin type can be used to help predict a person's risk of skin cancer from sun exposure, with the highest risk of skin cancer observed in people with the fairest skin (i.e., Type I or Type II skin). Individuals with types III to VI skin may also seek protection from visible light to prevent darkening and worsening of pigmentation disorders such as melasma.

[0006] Until recently, it was believed that sunburn was caused exclusively by light in the UV wavelength range (i.e., 10–400 nm) and that visible light wavelengths (i.e., above 400 nm) did not contribute significantly to sunburn. UV-induced erythema, commonly known as sunburn, was thought to be induced by direct absorption damage to specific chromophores (primarily DNA) and other proteins in the epidermis and dermis caused by exposure to UVB radiation, as well as indirect damage through photooxidation processes caused by UVB and UVA radiation. Due to UVA-induced photooxidative damage, absorbed radiation energy raises oxygen to triplet or singlet excited energy levels, where it can interact with and damage other surrounding cellular structures, ultimately resulting in skin erythema if present in sufficient quantities.

[0007] Action spectra were derived to describe the precise amount of radiation required to produce erythema at each specific wavelength and are reported to cover a wavelength range of approximately 250-400 nm. All published action spectra for erythema have stopped at exactly 400 nm, implying that wavelengths above 400 nm are insignificant and do not contribute to the erythema response. See, for example, Non-Patent Document 2.

[0008] In recent years, it has been discovered that this assumption is incorrect and that the visible portion of the electromagnetic spectrum, particularly the violet and / or blue regions around 400-500 nm, can and does play a role in the induction of erythema, especially when considering outdoor sun exposure, where the sun produces a large amount of visible light (e.g., 50%) compared with a relatively small amount of ultraviolet light (e.g., 5%) at ground level. For example, Zastrow and colleagues have shown that free radicals (excited oxygen molecules) can be generated in skin tissue by wavelengths spanning the ultraviolet and entire visible light spectrum. Combining the action spectrum with the terrestrial solar spectrum, it has been estimated that as much as 50% of the free radicals generated by sunlight are caused by the visible portion of the solar spectrum, and another 50% by the ultraviolet portion (see non-patent document 3).

[0009] Nevertheless, the active ingredients in conventional sunscreen products typically only block ultraviolet rays (primarily UVA and UVB) and are not concerned with the effects of visible light. Typical UV absorbers in sunscreen products can be either organic (e.g., avobenzone, oxybenzone, octyl methoxycinnamate, etc.) or inorganic (i.e., titanium dioxide, zinc oxide, etc.). Because many consumers do not want sunscreen to be visible on their skin, manufacturers of these products have been working hard to produce invisible sunscreen products. Zinc oxide and titanium dioxide have been widely used in sunscreen products since about 1987, but they are typically incorporated into sunscreen products using very small particle sizes, e.g., nano-sized particles. Nano-sized particles can minimize the visible appearance of zinc oxide and titanium dioxide, making the sunscreen virtually invisible on the skin after application, while still functioning to absorb the harmful effects of UV radiation from the sun (see Non-Patent Document 4).

[0010] Nanoparticle-sized zinc oxide and titanium dioxide may still function as UV filters, acting as semiconducting absorbers of UV radiation below approximately 370-380 nm, depending on their bandgap energy. Nevertheless, nanoparticle-sized zinc oxide and titanium dioxide, due to their micronized / nanoparticle size, scatter and reflect very little radiation beyond these wavelengths. Therefore, even these inorganic-based sunscreens may offer little or no protection against radiation in the visible portion of the electromagnetic spectrum and may offer reduced protection against wavelengths at the higher end of the UVA spectrum (e.g., 375-400 nm).

[0011] Iron oxide is a known visible light absorber, so it may be added to sunscreen products to provide broad protection against both UV and visible light.However, iron oxide exists in yellow, red, and brown tones, and the color of the iron oxide increases as the amount of iron oxide added to the sunscreen composition increases.Therefore, sunscreen compositions that contain high concentrations of iron oxide, or concentrations of iron oxide that are effective for protecting against visible light, may not be desirable for people with type I or type II skin, that is, people who need the most protection from visible light, to reduce the risk of skin cancer, erythema, and skin aging effects.

[0012] Therefore, there is a need for sunscreen compositions that provide protection against both the UV radiation of sunlight and the visible light portion of the sun's spectrum, where the sunscreen is in a shade that is acceptable to fair to light skinned individuals. Ideally, such sunscreen compositions should have a consumer-acceptable appearance and provide greater protection against erythema than conventional sunscreen products that only provide UV protection. [Prior art documents] [Non-patent literature]

[0013] [Non-Patent Document 1] Fitzpatrick et al., The Validity and Practicality of sun-reactive skin types I through VI, ARCHIVES OF DERM.1988, 124(6):869-871 [Non-patent document 2] Schmalwieser,A.et al.,A library of action spectra for erythema and pigmentation, PHOTOCHEM.PHOTOBIOL.SCI.2012;11(2):252-268 [Non-patent document 3] Zastrow,L.et al.,The missing link,light(280-1600nm)induced free radical formation in human skin,SKIN PHARMACOL.PHYSIOL.2009;22:31-34 [Non-patent document 4] Cole C.et al.,Metal oxide sunscreens protect skin by absorption, not by reflection or scattering,PHOTOMED.PHOTOIMMUNOL.PHOTODERMATOL.2016,32:1,5-10 Summary of the Invention

[0014] Disclosed herein are sunscreen compositions and methods of using the sunscreen compositions to reduce or prevent sunburn caused by both visible and ultraviolet (UV) radiation, as well as methods of increasing the sun protection factor (SPF) and / or visible light protection factor of the sunscreen compositions.

[0015] In certain embodiments, disclosed herein is a sunscreen composition comprising: (a) at least one inorganic UV filter selected from zinc oxide or titanium oxide, (b) at least one inorganic pigment selected from iron oxide, and (c) at least one visible light protector, such as barium sulfate, wherein the at least one visible light protector is present in an amount effective to reduce or prevent sunburn caused by visible light. In certain embodiments, disclosed herein is a sunscreen composition comprising: (a) at least one inorganic UV filter selected from zinc oxide or titanium oxide, (b) at least one inorganic pigment selected from iron oxide, and (c) at least two visible light protectors, including barium sulfate and mica, wherein the at least two visible light protectors are present in an amount effective to reduce or prevent sunburn caused by visible light.

[0016] In certain embodiments, the sunscreen compositions disclosed herein are anhydrous. In certain embodiments, the barium sulfate in the sunscreen composition is present in an amount ranging from about 0.1% to about 10% by weight, such as from about 1% to about 5% by weight, from about 2% to about 3% by weight, about 5% by weight, or about 2.5% by weight, based on the total weight of the composition. In certain embodiments, the mica in the sunscreen composition is present in an amount ranging from about 0.1% to about 10% by weight, such as from about 1% to about 5% by weight, from about 2% to about 3% by weight, about 5% by weight, or about 2.5% by weight, based on the total weight of the composition. In certain embodiments, both the barium sulfate and the mica are each present in the sunscreen composition in an amount ranging from about 1% to about 5% by weight, such as from about 2% to about 3% by weight, about 5% by weight, or about 2.5% by weight, based on the total weight of the composition. In further embodiments of the present disclosure, the sunscreen composition does not contain an organic UV filtering agent.

[0017] In certain embodiments of the present disclosure, the sunscreen composition includes both zinc oxide and titanium oxide, and in certain embodiments, the iron oxide is selected from the group consisting of black iron oxide, brown iron oxide, red iron oxide, yellow iron oxide, and mixtures thereof. In certain embodiments, at least one of the at least two visible light protection agents further includes a coating, such as a silica coating, and in certain embodiments, the mica and barium sulfate both include a coating, such as a silica coating.

[0018] In certain embodiments of the sunscreen compositions disclosed herein, the iron oxide is present in the sunscreen composition in an amount ranging from about 0.1% to about 10%, e.g., from about 1% to about 5%, from about 1% to about 3%, or from about 2% to about 3%. In certain embodiments, the at least one inorganic UV filtering agent is titanium dioxide, and in certain embodiments, the titanium dioxide has an average particle size ranging from about 5 nm to about 20 nm. In certain embodiments, the at least one UV filtering agent is zinc oxide, and in certain embodiments, the zinc oxide has an average particle size ranging from about 10 nm to about 100 nm.

[0019] In certain embodiments, the sunscreen compositions disclosed herein further comprise at least one antioxidant, such as at least one antioxidant selected from the group consisting of vitamin E or a derivative thereof and vitamin C or a derivative thereof. In certain embodiments, the at least one antioxidant is present in the sunscreen composition in a total amount ranging from about 0.1% to about 5% by weight, based on the total weight of the sunscreen composition.

[0020] Also disclosed herein is a method for reducing or preventing sunburn caused by visible light and ultraviolet (UV) radiation in a subject, comprising the step of topically applying to the subject a sunscreen composition disclosed herein, for example, a sunscreen composition comprising: (a) at least one inorganic UV filtering agent selected from zinc oxide or titanium oxide; (b) at least one inorganic pigment selected from iron oxide; and (c) at least one visible light protectant, such as barium sulfate, wherein the at least one visible light protectant is present in an amount effective to reduce or prevent sunburn caused by visible light. In certain embodiments, disclosed herein are methods for reducing or preventing sunburn caused by visible light and ultraviolet (UV) radiation in a subject, comprising the step of topically applying to the subject a sunscreen composition disclosed herein, such as a sunscreen composition comprising: (a) at least one inorganic UV filtering agent selected from zinc oxide or titanium oxide; (b) at least one inorganic pigment selected from iron oxide; and (c) at least two visible light protectants, the at least two visible light protectants comprising barium sulfate and mica, wherein the at least two visible light protectants are present in an amount effective to reduce or prevent sunburn caused by visible light.

[0021] Further disclosed herein is a method for increasing the visible light protection factor of a sunscreen composition disclosed herein, such as a sunscreen composition comprising (a) at least one inorganic UV filtering agent selected from zinc oxide or titanium oxide, (b) at least one inorganic pigment selected from iron oxide, and (c) at least one visible light protection agent, such as barium sulfate, wherein the at least one visible light protection agent is present in the sunscreen composition in an amount effective to enhance visible light protection across the entire electromagnetic wavelength spectrum, from about 400 nm to about 800 nm, e.g., from about 400 nm to about 500 nm. In certain embodiments of the methods disclosed herein, the visible light protection factor is increased by at least about 0.5, e.g., at least about 0.7, at least about 0.8, or at least about 0.9, i.e., the visible light protection factor may be increased, for example, by about 2.7 to about 3.2, representing an increase of about 0.5. In certain embodiments, disclosed herein is a method for increasing the visible light protection factor of a sunscreen composition disclosed herein, such as a sunscreen composition comprising (a) at least one inorganic UV filter selected from zinc oxide or titanium oxide, (b) at least one inorganic pigment selected from iron oxide, and (c) at least two visible light protection agents, including barium sulfate and mica, wherein the at least two visible light protection agents are present in the sunscreen composition in an amount effective to enhance visible light protection across the entire electromagnetic wavelength spectrum, from about 400 nm to about 800 nm, e.g., from about 400 nm to about 500 nm. In certain embodiments of the methods disclosed herein, the visible light protection factor is increased by at least about 0.5, e.g., at least about 0.7, at least about 0.8, or at least about 0.9.

[0022] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present teachings as claimed. [Brief explanation of the drawings]

[0023] [Figure 1]1 is a graph showing the absorbance of six sunscreen formulations described in Example 1 across the UV and visible light spectrum (300-800 nm) of the electromagnetic spectrum. [Figure 2] 1 is a graph showing the absorbance of four sunscreen formulations #1, #2, #3, and #4 described in Example 2 across the UV and visible light spectrum (300-800 nm) of the electromagnetic spectrum. [Figure 3] 1 is a graph showing the absorbance of four sunscreen formulations #5, #7, #8, and #9 described in Example 2 across the UV and visible light spectrum (300-800 nm) of the electromagnetic spectrum. [Figure 4] 1 is a graph showing the absorbance of seven sunscreen formulations #7, #8, #9, #9a, #9b, #10, and #11 described in Example 2 across the UV and visible light spectrum (300-800 nm) of the electromagnetic spectrum. [Figure 5] 1 is a graph showing the dose response of blue light (approximately 400-500 nm) protection in relation to iron oxide concentration of the sunscreen formulation described in Example 2. [Figure 6] 1 is a bar graph showing the blue light protection factor of sunscreen formulations #2, #3, #4, #5, #6, and #7 described in Example 2. Error bars indicate CI=95%, and brackets above the bars indicate statistical significance, with p<0.01 for the comparison of formulations #2 and #3, and p<0.1 for the comparison of formulations #3 and #4. Similarly, p<0.011 for the comparison of formulations #5 and #6, and p<0.01 for the comparison of formulation #7 with either formulation #5 or #6. [Figure 7] 1 is a graph showing the critical wavelength dependence (for increasing iron oxide concentration) on iron oxide concentration for sunscreen formulations #9b, #9a, #9, #8, #7, and #10 described in Example 2. [Figure 8] 1 is a graph showing the absorbance of four sunscreen formulations #1213A, #1213B, #1122B, and #1212B across the UV and visible light spectrum (300-700 nm) of the electromagnetic spectrum, as well as the absorbance resulting from mica alone minus the 4.4% TiO spectrum as described in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0024] Reference will now be made in detail to embodiments of the present teachings. The following description refers to exemplary embodiments in which the present teachings may be practiced. As such, the following description is merely exemplary.

[0025] Disclosed herein are sunscreen compositions that provide protection to the skin against both the visible and UV portions of sunlight, as well as methods of using the sunscreen compositions to reduce or prevent sunburn resulting from both the visible and UV portions of sunlight, and methods of increasing the SPF and / or visible light protection factor of sunscreen compositions. The sunscreen compositions disclosed herein contain a combination of inorganic agents that absorb the sun's visible light, primarily in the blue region, thereby reducing or preventing erythema.

[0026] In certain embodiments, disclosed herein are sunscreen compositions comprising at least one visible light protection agent. Also disclosed herein are sunscreen compositions comprising at least two visible light protection agents, such as barium sulfate and mica.

[0027] In certain embodiments, the sunscreen composition may further comprise iron oxide as an inorganic pigment that also acts to absorb visible light, and in certain embodiments, the sunscreen composition may further comprise iron oxide together with at least one inorganic UV filtering agent, such as titanium dioxide and / or zinc oxide.

[0028] In certain embodiments, the sunscreen compositions disclosed herein are anhydrous, and in certain embodiments, the sunscreen compositions are in the form of an emulsion, such as an oil-in-water emulsion or a water-in-oil emulsion. The anhydrous sunscreen compositions disclosed herein can provide superior water resistance when topically applied to a user's skin compared to aqueous sunscreen compositions, and in certain embodiments, the anhydrous sunscreen compositions can be waterproof. Furthermore, the anhydrous sunscreen compositions may have enhanced resistance to microbial contamination compared to aqueous sunscreen compositions. In certain embodiments, the anhydrous sunscreen compositions disclosed herein are substantially free of preservatives.

[0029] The sunscreen compositions disclosed herein provide superior protection against sun-induced erythema compared to conventional sunscreen products, including, for example, conventional sunscreens that do not provide a combination of visible light blocking agents. At least two visible light protecting agents, such as barium sulfate and mica, provide synergistic and superior visible light protection compared to iron oxide alone, as well as one visible light protecting agent alone, thereby allowing the sunscreen composition to provide equivalent or superior visible light protection while reducing the iron oxide content, which may be undesirable as a pigment in colored sunscreens for fair-skinned individuals. Thus, the sunscreen compositions disclosed herein provide visible light protection in a cosmetically acceptable manner and can be tailored in concentration (e.g., iron oxide concentration) and color grade to suit the user's skin tone.

[0030] The sunscreen compositions disclosed herein can be formulated to provide a pleasant physical feel and touch to the user. In certain embodiments, the sunscreen is formulated to provide an acceptable color for individuals, such as individuals with Fitzpatrick Type I or Type II skin. In certain embodiments, the sunscreen is formulated to provide an acceptable color for individuals with Fitzpatrick Type III, Type IV, Type V, or Type VI skin. [Definition]

[0031] As used throughout, ranges are used as a shorthand notation to describe all values within that range. Any value within that range can be selected as the endpoint of the range. Furthermore, all references cited herein are incorporated by reference in their entirety. In the event of a conflict between the definitions in this disclosure and those in the references, the present disclosure shall control. The following terms and their equivalents shall have the following meanings, unless the context clearly indicates otherwise:

[0032] The term "at least one" is used to mean that one or more of the listed items can be selected. For example, if the list of items is A and B, at least one of A and B refers to A only, B only, or A and B.

[0033] The term "about" is understood to encompass the range of normal variation accepted in the art, and can include, for example, within 10%, within 1%, within 0.1%, or within 0.01% of a stated value. Unless otherwise indicated, all numerical values provided herein are understood to be modified by the term about.

[0034] As used herein, the term "erythema" is used interchangeably with the term "sun dermatitis" and refers to the superficial redness of the skin caused by excessive exposure to waves from the electromagnetic spectrum, including both visible light and UV radiation. As used herein, erythema and sun dermatitis are distinguished from increased pigmentation of the skin (e.g., sunburn).

[0035] As used herein, the terms "ultraviolet radiation" or "UV radiation" refer to electromagnetic radiation in the range of about 290 nm to about 400 nm. Within the spectrum of UV radiation, UVB radiation is electromagnetic radiation in the range of about 290 nm to about 320 nm, while UVA radiation is electromagnetic radiation in the range of about 320 to about 400 nm.

[0036] As used herein, the term "visible light" refers to electromagnetic radiation within the range of about 400 nm to about 700 nm. Within the visible light spectrum, the violet region spans about 380 to 450 nm, the blue region spans about 450 to 495 nm, the green region spans about 495 to 570 nm, the yellow region spans about 570 to 590 nm, the orange region spans about 590 to 625 nm, and the red region spans about 625 to 700 nm. In certain embodiments, the blue region can be combined with the violet region to describe the blue region spanning about 400 nm to about 500 nm.

[0037] As used herein, the terms "sun protection factor" and "SPF" refer to a measure of how much solar energy is required to cause erythema or sunburn on skin after application of a sunscreen composition, compared to the amount of solar energy required to cause erythema on skin without any sunscreen composition applied. The amount of solar energy can be affected by both the length (time) and intensity of exposure to solar energy. Solar radiation intensity can be related to time of day, geographic location (higher latitudes may result in greater solar radiation intensity), and weather (e.g., cloud cover).

[0038] As used herein, the term "visible light protection factor" or "VL-PF" refers to a measure of the effectiveness of a sunscreen composition in preventing the effects of erythema or sunburn caused by the sun's visible light after application of the sunscreen composition, compared to the amount of solar energy required to produce erythema on skin without any sunscreen composition applied. In certain embodiments, the VL-PF corresponds to the reciprocal of the average transmittance value over a given wavelength range, e.g., from about 400 nm to about 800 nm, from about 400 nm to about 600 nm, or from about 400 nm to about 500 nm.

[0039] As used herein, the term "effective amount" refers to the amount of sunscreen composition that, when applied or administered in appropriate amounts and at appropriate frequencies, is sufficient to prevent, reduce or mitigate damage resulting from exposure to ultraviolet radiation and visible light, including sunburn.

[0040] Additional definitions are set forth throughout the detailed description. [Sunscreen composition]

[0041] Disclosed herein are sunscreen compositions that, when topically applied to a user's skin, are useful for reducing or preventing damage caused by visible light and UV radiation, including sunburn.

[0042] In certain embodiments, a sunscreen composition is disclosed that includes: (a) at least one inorganic UV filtering agent, such as titanium oxide and / or zinc oxide, (b) at least one inorganic pigment selected from iron oxide, and (c) at least one visible light protection agent, wherein the at least one visible light protection agent is present in an amount effective to reduce or prevent sunburn caused by visible light. In certain embodiments, a sunscreen composition is disclosed that includes: (a) at least one inorganic UV filtering agent, such as titanium oxide and / or zinc oxide, (b) at least one inorganic pigment selected from iron oxide, and (c) at least two visible light protection agents comprising or consisting of barium sulfate and mica, wherein the at least two visible light protection agents are present in an amount effective to reduce or prevent sunburn caused by visible light. [UV filtering agent]

[0043] In certain embodiments, the sunscreen composition comprises at least one inorganic UV filtering agent selected from the group consisting of titanium dioxide, zinc oxide, cerium oxide, zirconium oxide, and mixtures thereof, which may serve to filter or absorb UV radiation from the UV band of the electromagnetic spectrum, including, for example, UVA and UVB radiation, approximately 320-400 nm and 280-320 nm, respectively.

[0044] In certain embodiments, the sunscreen compositions disclosed herein may include titanium dioxide as an inorganic UV filtering agent. The titanium dioxide may be micronized or nanosized, and may be present as solid particles having an average particle size ranging, for example, from about 10 nm to about 100 μm, e.g., from about 10 nm to about 25 μm, from about 10 nm to about 10 μm, or from about 15 nm to about 5 μm. In certain embodiments in which titanium dioxide is present as a UV filtering agent, the titanium dioxide may comprise nanoparticles having an average particle size ranging from about 5 nm to about 1000 nm, e.g., from about 5 nm to about 500 nm, from about 10 nm to 50 nm, or from about 15 nm to about 40 nm, or about 15 nm. The titanium dioxide nanoparticles may also form agglomerate particles having a larger average particle size, e.g., a mean agglomerate particle size ranging from about 100 nm to about 1000 nm, e.g., from about 200 nm to about 500 nm, or from about 250 nm to about 400 nm. In certain embodiments, the titanium dioxide may be larger than nanoparticle size, having an average particle size ranging from about 1 μm to about 25 μm, e.g., from about 5 μm to about 20 μm, or from about 10 μm to about 15 μm. In certain embodiments, the titanium dioxide comprises a mixture of nanoparticles (e.g., for UV filtering protection) and larger micronized size particles (e.g., for visible light scattering protection).

[0045] Titanium dioxide may be present in the sunscreen composition, alone or together with other sunscreen ingredients, in any effective amount that, when topically applied to a user, blocks ultraviolet light so as to prevent or reduce the effects of sunburn. In embodiments, titanium dioxide may be present in the sunscreen composition in an amount ranging from about 1% to about 25% by weight, e.g., from about 5% to about 20% by weight, or from about 5% to about 15% by weight, e.g., about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 12.5%, about 13%, about 14%, or about 15% by weight, based on the total weight of the sunscreen composition.

[0046] In various embodiments of the present disclosure, the sunscreen composition includes zinc oxide as an inorganic UV filter in addition to or instead of titanium dioxide. As described above for titanium dioxide, the zinc oxide may be micronized or nanosized, and present as solid particles having an average particle size ranging, for example, from about 10 nm to about 400 μm, e.g., from about 10 nm to about 25 μm, from about 10 nm to about 10 μm, or from about 15 nm to about 5 μm. As used herein, "nanosized" or "nanoparticle" refers to a particle size that is less than about 1000 nm, e.g., from about 1 nm to about 1000 nm or from about 1 nm to about 100 nm, while "micronized" or "microsized" refers to a particle size ranging from about 1 μm (i.e., about 1000 nm) to about 1000 μm. In embodiments in which zinc oxide is present as a UV filtering agent, the zinc oxide may comprise nanoparticles having an average particle size ranging from about 5 nm to about 1000 nm, e.g., from about 10 nm to about 1000 nm, from about 30 nm to about 200 nm, from about 40 nm to about 100 nm, from about 60 nm to about 80 nm, from about 10 nm to about 50 nm, or from about 25 nm to about 40 nm, or about 80 nm. However, as discussed below, zinc oxide may also be present in the sunscreen compositions disclosed herein as at least one inorganic pigment at pigment size, indicating that the zinc oxide may be larger than nanoparticle size and have an average particle size ranging from about 100 nm to about 1000 nm, e.g., from about 200 nm to about 500 nm, or from about 1 μm to about 400 μm, e.g., from about 10 μm to about 100 μm, from about 2 μm to about 25 μm, from about 5 μm to about 20 μm, or from about 10 μm to about 15 μm. In certain embodiments, the zinc oxide comprises a mixture of nanoparticles (eg, for UV filtering protection) and larger, micronized sized particles (eg, for visible light scattering prevention).

[0047] Zinc oxide, alone or in combination with other sunscreen ingredients, may be present in the sunscreen composition in any effective amount to filter ultraviolet light so as to prevent or reduce the effects of sunburn when topically applied to a user. In certain embodiments, zinc oxide may be present in the sunscreen composition in an amount ranging from about 1 wt. % to about 25 wt. %, e.g., from about 5 wt. % to about 20 wt. %, or from about 5 wt. % to about 15 wt. %, e.g., about 5 wt. %, about 6 wt. %, about 7 wt. %, about 7.5 wt. %, about 8 wt. %, about 9 wt. %, 10 wt. %, about 11 wt. %, about 12 wt. %, about 13 wt. %, or about 15 wt. %, based on the total weight of the sunscreen composition.

[0048] Overall, the inorganic UV filtering agents, including both zinc oxide and titanium dioxide, may be present in the sunscreen composition in an amount ranging from about 2 wt. % to about 50 wt. %, e.g., from about 5 wt. % to about 40 wt. %, from about 10 wt. % to about 30 wt. %, or from about 20 wt. % to about 25 wt. %, e.g., about 20 wt. %, about 21 wt. %, about 22 wt. %, about 23 wt. %, about 23.5 wt. %, about 24 wt. %, or about 25 wt. %, based on the total weight of the sunscreen composition.

[0049] In certain embodiments, sunscreen compositions can be formulated for use by fair-skinned users, for example, for use by users with Fitzpatrick type I or type II skin.In such embodiments, the amount of titanium dioxide in the composition can be greater than the amount of zinc oxide in the composition.Without wishing to be bound by theory, it is believed that titanium oxide may contribute more to SPF protection than zinc oxide.

[0050] In certain embodiments, at least one inorganic UV filter can be a surface-treated inorganic UV filter. Surface-treating at least one inorganic UV filter can reduce or prevent the photoreactivity of the agent and / or facilitate mixing with other components in the sunscreen composition. Surface-treated inorganic UV filter refers to a UV filter that has been surface-treated by any means, including chemical, electrical, and / or mechanical means. In certain embodiments, surface-treating at least one inorganic UV filter can improve the water resistance of the UV filter and the sunscreen composition. In certain embodiments, all UV filters present in the sunscreen composition are surface-treated to reduce the potential photoreactivity of the UV filter.

[0051] Inorganic UV filtering agent can be surface-treated by any surface treatment method or agent known in the art.In certain embodiments, at least one inorganic UV filtering agent can comprise coated particles.Coating can comprise hydrophobic materials such as alkylsiloxane (for example, triethoxycaprylylsilane), organic titanate, halogenated phosphate (for example, perfluoroalkylphosphonate), halogenated organosilane, modified amino acid (for example, disodium stearoyl glutamate), silicone or metal salt of fatty acid.

[0052] Representative embodiments of surface-treated coated UV filters may include coated zinc oxide, such as triethoxycaprylylsilane zinc oxide (e.g., Z-Cote™ HP1), and / or coated titanium dioxide, such as triethoxycaprylylsilane titanium dioxide (e.g., CM3K40T4 and UV Cut TiO2-41 from Kobo products). [Inorganic pigments]

[0053] In various embodiments, the sunscreen compositions disclosed herein may further comprise at least one inorganic pigment, such as iron oxide. While not wishing to be bound by theory, it is believed that the inorganic pigment acts to absorb visible light from the sun, such as light in the blue region of the visible light spectrum (e.g., about 450 nm to about 495 nm) and the violet region of the visible light spectrum (e.g., about 380 nm to about 450 nm), which may overlap with UVA radiation at the upper end of the UVA spectrum (e.g., about 375 nm to about 400 nm). Representative inorganic pigments may include titanium dioxide; zinc oxide; iron oxides, including black iron oxide, brown iron oxide, red iron oxide, and yellow iron oxide; manganese violet; ultramarine blue; chromium oxide; chromium hydroxide; ferric blue; and mixtures thereof. In certain embodiments, the at least one inorganic pigment comprises a mixture of iron oxides, such as a mixture of red iron oxide, yellow iron oxide, and black iron oxide. Note that titanium dioxide and zinc oxide have band gap energies of about 3.3 eV and stop absorbing at about 375-380 nm, instead scattering at wavelengths beyond this range. Iron oxide and other oxides have band gap energies of only about 2.1-2.2 eV, absorbing out to about 500-590 nm and may scatter beyond that wavelength range.

[0054] In one embodiment, the at least one inorganic pigment comprises iron oxide, and in one embodiment, the at least one inorganic pigment comprises iron oxide and at least one of zinc oxide and titanium dioxide. While conventional nano-sized particles of inorganic UV filters, such as titanium dioxide and zinc oxide, can be useful in providing UVB protection against radiation in the range of about 280 nm to about 320 nm, these agents often do not adequately protect against erythema at higher radiation wavelengths that constitute UVA radiation, such as about 315 nm to about 400 nm, including about 375 nm to about 400 nm. However, as disclosed herein, the addition of at least one inorganic pigment, such as iron oxide, titanium dioxide, and / or zinc oxide, can enhance protection against erythema from UVA radiation and / or visible light, including protection from UVA radiation in the range of about 375 nm to about 400 nm and visible light in the range of about 400 nm to about 750 nm.

[0055] In embodiments in which the at least one inorganic pigment comprises titanium dioxide and / or zinc oxide, the titanium dioxide and / or zinc oxide may have a larger particle size than the titanium dioxide and / or zinc oxide constituting the UV filter. Smaller nano-sized particles of titanium dioxide and / or zinc oxide are known to provide broad-spectrum UV filtering and absorption properties, but when applied to the skin in a sunscreen composition, they have less ability to scatter and reflect visible light, making them more transparent. See, for example, Yin, H. et al., A comparative study of the physical and chemical properties of nano-sized ZnO particles from multiple batches of three commercial products, J. NANOPART. RES. 2015;17:1-19.

[0056] Thus, in certain embodiments where the sunscreen compositions disclosed herein contain zinc oxide nanoparticles and / or titanium dioxide nanoparticles as UV filters, the sunscreen compositions may further contain at least one inorganic pigment selected from the group consisting of pigmentary zinc oxide and pigmentary titanium dioxide. "Pigmentary" or "pigmentary" refers to the titanium dioxide and / or zinc oxide having an average particle size larger than the aforementioned nano-sized particles and cosmetically acceptable for use as a pigment in a sunscreen composition. In certain embodiments, the zinc oxide pigmentary particles may have an average particle size ranging from at least about 100 nm to about 25 μm, e.g., from about 200 nm to about 10 μm, from about 200 nm to about 500 nm, or from about 5 μm to about 15 μm. In certain embodiments, the pigment-sized particles of titanium dioxide may have an average particle size ranging from at least about 100 nm to about 25 μm, e.g., from about 200 nm to about 10 μm, from about 200 nm to about 500 nm, from about 5 μm to about 15 μm, or from about 8 μm to about 10 μm. The at least one inorganic pigment may be present in the sunscreen composition, alone or together with other components of the sunscreen composition, in any effective amount to absorb visible light, e.g., visible light from the blue and / or violet region of the visible light spectrum. In certain embodiments, the at least one inorganic pigment, e.g., iron oxide, is present in the sunscreen composition in an amount ranging from about 0.01 wt % to about 10 wt %, e.g., from about 1 wt % to about 5 wt %, from about 1 wt % to about 4.5 wt %, or from about 1 wt % to about 3 wt %, e.g., about 0.5 wt %, about 1 wt %, about 1.5 wt %, about 2 wt %, about 2.5 wt %, or about 2.75 wt %, based on the total weight of the sunscreen composition. In certain embodiments, the iron oxide is present in the sunscreen composition in an amount of less than 5 wt.%, for example, less than about 4.5 wt.%, less than about 3 wt.%, less than about 2.75 wt.%, less than about 2.5 wt.%, less than about 2 wt.%, less than about 1.5 wt.%, less than about 1 wt.%, or less than about 0.5 wt.%, based on the total weight of the sunscreen composition. In some embodiments, the composition is substantially free of iron oxide. Thus, also disclosed herein is a sunscreen composition comprising at least one inorganic UV filter selected from zinc oxide or titanium dioxide and at least two visible light protection agents, including barium sulfate and mica, wherein the at least two visible light protection agents are present in an amount effective to reduce or prevent sunburn caused by visible light.

[0057] In certain embodiments, the at least one inorganic pigment may be a surface-treated inorganic pigment. Surface-treating the at least one inorganic pigment can reduce or prevent the pigment's photoreactivity and / or aid in mixing with other ingredients in the sunscreen composition. Surface-treated inorganic pigment indicates that the inorganic pigment has been surface-treated by any means, including chemical, electrical, and / or mechanical means. In certain embodiments, surface-treating the at least one inorganic pigment can increase the water resistance of the inorganic pigment and the sunscreen composition. In certain embodiments, all inorganic pigments present in the sunscreen composition are surface-treated.

[0058] Inorganic pigments can be surface-treated by any surface treatment method or agent known in the art.In certain embodiments, at least one inorganic pigment may comprise coated particles.The coating may comprise hydrophobic materials such as alkylsiloxanes (e.g., triethoxycaprylylsilane), organic titanates, halogenated phosphates (e.g., perfluoroalkylphosphonates), halogenated organosilanes, modified amino acids (e.g., disodium stearoyl glutamate), silicones, or metal salts of fatty acids.

[0059] Representative embodiments of organic pigments may include surface-treated coated inorganic pigments, such as coated iron oxides, including triethoxycaprylylsilane iron oxide (e.g., Unipure™), and coated and uncoated titanium dioxide (e.g., Unipure™ White LC 987 and Unipure™ White LC 987 AS-EM, triethoxycaprylylsilane titanium dioxide). [Additional visible light protection]

[0060] In certain embodiments, the sunscreen compositions disclosed herein further comprise at least one visible light protection agent, such as barium sulfate, in addition to at least one inorganic pigment. In certain embodiments, the sunscreen compositions further comprise at least two additional visible light protection agents, such as barium sulfate and mica. Visible light protection agents may include any compound, such as an inorganic pigment, that blocks or absorbs light from the visible portion of the electromagnetic spectrum, e.g., electromagnetic wavelengths within the range of about 400 nm to about 700 nm. In certain embodiments, the visible light protection agent blocks or absorbs light in the violet and / or blue light regions, e.g., from about 380 nm to about 500 nm, from about 400 nm to about 495 nm, or from about 400 nm to about 500 nm. In certain embodiments, the visible light protection agent blocks or absorbs light in the violet light region, e.g., about 380 nm to about 450 nm, and in certain embodiments, the light absorber blocks or absorbs light in the blue light region, e.g., about 450 nm to about 495 nm. In certain embodiments, the visible light protection agent blocks or absorbs light in the green light region, e.g., about 495 nm to about 570 nm; the yellow light region, e.g., about 570 nm to about 590 nm; the orange light region, e.g., about 590 nm to about 625 nm; and / or the red light region, e.g., about 625 nm to about 700 nm.

[0061] Visible light protection agents may include, by way of non-limiting example, at least one or at least two of transition metal oxides, iron oxide, barium sulfate, mica, silica, bismuth oxychloride, cornstarch, chalk powder, or any visible color pigment known in the art. In certain embodiments, at least one visible light protection agent is barium sulfate. In certain embodiments, at least one visible light protection agent is mica. In certain embodiments, at least two visible light protection agents are barium sulfate and mica. In certain embodiments, the sunscreen composition is substantially free of bismuth oxychloride. In certain embodiments, the sunscreen composition is substantially free of any visible light protection agents except barium sulfate and / or mica.

[0062] The at least one or at least two visible light protection agents may be present in the sunscreen composition, alone or together with other components of the sunscreen composition, such as iron oxide, titanium oxide, and / or zinc oxide, in any effective amount to absorb visible light, e.g., visible light from the blue and / or violet region of the visible light spectrum.

[0063] In the embodiments disclosed herein, at least two visible light protection agents may be present in synergistic amounts, so that the presence of at least two visible light protection agents can block more visible light than if any of the visible light protection agents acted alone.For example, barium sulfate and mica may be present in the sunscreen composition in synergistic amounts.In certain embodiments, at least one or at least two visible light protection agents or agents may be present in the sunscreen composition in synergistic amounts with another component of the sunscreen composition, such as at least one antioxidant.

[0064] As used herein, the terms "synergistic effect," "synergistically," and their derivatives refer to the activity of a combination, such as a combination of at least two visible light protection agents, that is greater than the combined activity of the visible light protection agents when applied individually.In some embodiments, each individual visible light protection agent may have minimal visible light protection effect when applied separately, but the same amount of visible light protection agent may have high visible light protection ability when applied together in a sunscreen composition, resulting in a higher SPF and / or visible light protection factor.This synergistic effect of at least two visible light protection agents is surprising and unexpected.

[0065] In certain embodiments, the at least one visible light protectant, such as barium sulfate, is present in the sunscreen composition in an amount ranging from about 0.01% to about 10% by weight, e.g., from about 1% to about 7% by weight, from about 1% to about 5% by weight, or about 5% by weight, based on the total weight of the sunscreen composition.

[0066] In certain embodiments, at least two visible light protection agents, such as barium sulfate and mica, are present together in the sunscreen composition in an amount ranging from about 0.01 wt. % to about 10 wt. %, e.g., from about 1 wt. % to about 7 wt. %, from about 1 wt. % to about 5 wt. %, or about 5 wt. % based on the total weight of the sunscreen composition. In certain embodiments, at least two visible light protection agents, such as barium sulfate and mica, are present together in the sunscreen composition in an amount ranging from about 0.01 wt. % to less than about 7 wt. %, e.g., from about 3.5 wt. % to less than about 7 wt. %, from about 4 wt. % to less than about 7 wt. %, from about 4.5 wt. % to less than about 7 wt. %, or from about 5 wt. % to less than about 7 wt. % based on the total weight of the sunscreen composition. The amounts of barium sulfate and mica in the composition may be the same or different.

[0067] In certain embodiments of the sunscreen compositions disclosed herein, barium sulfate is present in an amount ranging from about 0.01 wt % to about 5 wt %, e.g., from about 1 wt % to about 3.5 wt %, from about 1 wt % to about 3 wt %, from about 1.5 wt % to about 2.5 wt %, from about 2 wt % to about 2.5 wt %, or about 2.5 wt %, based on the total weight of the sunscreen composition. In certain embodiments of the sunscreen compositions disclosed herein, mica is present in an amount ranging from about 0.01 wt % to about 5 wt %, e.g., from about 1 wt % to about 3.5 wt %, from about 1 wt % to about 3 wt %, from about 1.5 wt % to about 2.5 wt %, from about 2 wt % to about 2.5 wt %, or about 2.5 wt %, based on the total weight of the sunscreen composition. In certain embodiments disclosed herein, both barium sulfate and mica are present in the sunscreen composition in equal amounts, such as about 1% to about 3%, about 1.5% to about 2.5%, about 2% to about 2.5%, or about 2.5% by weight, respectively, based on the total weight of the sunscreen composition. In one embodiment disclosed herein, the sunscreen composition comprises at least two visible light protection agents, including barium sulfate and mica, and the barium sulfate is present in an amount of about 2.5% by weight and the mica is present in an amount of about 2.5% by weight, based on the total weight of the sunscreen composition.

[0068] In certain embodiments disclosed herein, at least one of the at least two visible light protectors may be a surface-treated visible light protector. Surface-treating at least one visible light protector can reduce or prevent the photoreactivity of the agent and / or aid in mixing with other components in the sunscreen composition. Surface-treated visible light protector indicates that the visible light protector has been surface-treated by any means, including chemical, electrical, and / or mechanical means. In certain embodiments, surface-treating at least one visible light protector can improve the water resistance of the visible light protector and the sunscreen composition. In certain embodiments, both of the at least two visible light protectors present in the sunscreen composition (e.g., both barium sulfate and mica) are surface-treated, and in certain embodiments, only one of the at least two visible light protectors present in the sunscreen composition (e.g., either barium sulfate or mica) is surface-treated.

[0069] The visible light protection agent can be surface-treated by any surface treatment method or agent known in the art.In certain embodiments, at least one visible light protection agent can comprise coated particles.The coating can comprise hydrophobic materials such as alkylsiloxane (for example, triethoxycaprylylsilane), organic titanate, halogenated phosphate (for example, perfluoroalkylphosphonate), halogenated organosilane, modified amino acid (for example, disodium stearoyl glutamate), silicone, or metal salt of fatty acid.

[0070] Exemplary embodiments of surface-treated coated visible light protection agents can include, for example, coated barium sulfate, such as triethoxycaprylylsilane barium sulfate, and / or coated mica, such as triethoxycaprylylsilane mica. [Additional Ingredients]

[0071] The sunscreen composition of the present disclosure may contain any other cosmetically acceptable ingredient known in the art for use in topical sunscreen products.For example, in certain embodiments, the sunscreen composition disclosed herein further comprises at least one of the following cosmetically acceptable carriers: antioxidant, emollient / oil, emulsifier, SPF booster, organic pigment, organic UV filter, skin conditioning agent, film-forming agent, filler, preservative, fragrance, silica, sodium chloride, citric acid, neutralizing agent or pH adjuster (e.g., triethanolamine and sodium hydroxide), essential oil, and water.In certain embodiments, the sunscreen composition disclosed herein is substantially free of water and is an anhydrous sunscreen composition.

[0072] In certain embodiments disclosed herein, the sunscreen composition further comprises at least one antioxidant. Without wishing to be bound by theory, it is believed that the at least one antioxidant helps to eliminate free radicals induced by the sun's visible light radiation, thereby effectively preventing or alleviating sunburn when topically applied to a user in an amount effective to eliminate free radicals. In certain embodiments, the at least one antioxidant can be selected from vitamin A, vitamin C, vitamin E, selenium, carotenoids (e.g., beta-carotene), thiols, and derivatives and mixtures thereof. In certain embodiments, the at least one antioxidant is vitamin E (e.g., tocopherol) or a derivative thereof, such as tocopherol acetate. In certain embodiments, the at least one antioxidant is vitamin C (e.g., ascorbic acid) or a derivative thereof, such as tetrahexyldecyl ascorbate. In certain aspects of the present disclosure, the at least one antioxidant comprises both vitamin E or a derivative thereof and vitamin C or a derivative thereof.

[0073] At least one antioxidant may be present in the sunscreen compositions disclosed herein, alone or in combination with other components of the sunscreen composition, in any effective amount to prevent or reduce sunburn caused by radiation in the visible light region of the electromagnetic spectrum (e.g., about 400-750 nm). In certain embodiments, vitamin C or a derivative thereof, such as tetrahexyldecyl ascorbate, is present in the sunscreen composition in an amount ranging from about 0.01% to about 5% by weight, e.g., from about 0.1% to about 3% by weight, from about 0.2% to about 2% by weight, or from about 0.2% to about 1% by weight, based on the total weight of the sunscreen composition. In certain embodiments, vitamin E or a derivative thereof, such as tocopherol acetate, is present in the sunscreen composition in an amount ranging from about 0.01% to about 5% by weight, e.g., from about 0.1% to about 3% by weight, from about 0.2% to about 2% by weight, or from about 0.2% to about 1% by weight, based on the total weight of the sunscreen composition. In certain embodiments, the at least one antioxidant is a combination of vitamin C or a derivative thereof and vitamin E or a derivative thereof, and is present in the sunscreen composition in an amount ranging from about 0.1% to about 10% by weight, e.g., from about 0.2% to about 5% by weight, from about 0.5% to about 4% by weight, or from about 0.4% to about 2% by weight, based on the total weight of the sunscreen composition.

[0074] In certain embodiments, the sunscreen composition further comprises at least one organic UV filter; in certain embodiments, the sunscreen composition does not comprise an organic UV filter, and therefore the only UV filter in the sunscreen composition is an inorganic UV filter.Conventional organic UV filters are small aromatic molecules, but any organic UV filter known in the art can be considered within the scope of the embodiments disclosed herein.For example, the at least one organic UV filter disclosed herein can be benzophenone (e.g., benzophenone-3, benzophenone-5, and benzophenone-8), 3-benzylidene camphor, bis-ethylhexyloxyphenol methoxyphenyl triazine, butyl methoxydibenzoylmethane, camphor benzalkonium methosulfate, diethylamino hydroxybenzoyl hexyl benzoate, diethylhexyl butamido triazone, drometrizole trisiloxane, ethoxyethyl methoxycinnamate, dimethicone, methyl ... The alkyl acrylate may be selected from ethylhexyl p-aminobenzoate, ethylhexyl methoxycinnamate, ethylhexyl salicylate, ethylhexyl triazone, homosalate, isoamyl p-methoxycinnamate, methyl anthranilate, 4-methylbenzylidene camphor, methylene bisbenzotriazolyl tetramethylbutylphenol, octocrylene, para-aminobenzoic acid (PABA), polyacrylamidomethylbenzylidene camphor, polysilicone-15, triethanolamine salicylate, and terephthalylidene dicamphor sulfonic acid.

[0075] In certain embodiments, the sunscreen composition further comprises at least one humectant, such as, for example, butylene glycol or glycerin.

[0076] In certain embodiments, the sunscreen composition may include at least one emollient. Suitable emollients may be selected from any emollient known in the art, including, for example, mineral oil, petroleum oil, vegetable / plant oil, such as triglycerides (e.g., caprylic / capric triglyceride), wax (e.g., beeswax), isopropyl palmitate, isopropyl myristate, diisopropyl adipate, dibutyl adipate, butyloctyl salicylate, C12-C15 alkyl benzoate, silicone oil (e.g., dimethicone and stearyl dimethicone), animal oil, hydrocarbon oil, and fatty acid. By way of example, the at least one emollient may be selected from alkane oils such as isododecane and isohexadecane, ester oils, ether oils (e.g., dicaprylyl ether), and artificial triglycerides (e.g., caprylic / caprylyl glycerides, glyceryl trimyristate, glyceryl tripalmitate, glyceryl trilinolenate, glyceryl trilaurate, glyceryl tricaprate, glyceryl tricaprylate, capric / caprylic triglyceride, capric / caprylic / linolenic triglyceride, and mixtures thereof).

[0077] Representative ester oils include, for example, ethyl palmitate; ethylhexyl palmitate; isopropyl palmitate; dicaprylyl carbonate; alkyl myristates, such as isopropyl myristate and ethyl myristate; isocetyl stearate; 2-ethylhexyl isononanoate; isononyl isononanoate; isodecyl neopentanoate; isostearyl neopentanoate; diethyl sebacate; isopropyl lauroyl sarcosinate; diisopropyl sebacate; bis(2-ethylhexyl) sebacate; diisopropyl adipate; di-n-propyl adipate; dioctyl adipate; bis(2-ethylhexyl) adipate; diisostearyl adipate; bis(2-ethylhexyl) maleate; triisopropyl citrate; triisocetyl citrate; triisostearyl citrate; glyceryl trilactate; glyceryl trioctanoate. These may include ceryl; trioctyldodecyl citrate; trioleyl citrate; neopentyl glycol diheptanoate; diethylene glycol diisononanoate; diisopropyl adipate; dioctyl adipate; 2-ethylhexyl hexanoate; ethyl laurate; cetyl octanoate; octyldodecyl octanoate; myristyl propionate; 2-ethylhexyl 2-ethylhexanoate; 2-ethylhexyl octanoate; 2-ethylhexyl caprylate / caprate; methyl palmitate; isononyl isononanoate; isohexyl laurate; hexyl laurate; isopropyl isostearate; isodecyl oleate; glyceryl tri(2-ethylhexanoate); pentaerythrityl tetra(2-ethylhexanoate); di-2-ethylhexyl succinate; C10-30 cholesterol / lanosterol esters; and mixtures thereof.

[0078] In certain embodiments, sunscreen compositions may further comprise at least one SPF booster. SPF booster is a compound that acts to refract UV radiation, thereby increasing the path length of light in the medium, and when both compounds are combined, further enhances the UV absorption interaction with UV filtering agents.For example, in certain embodiments, styrene copolymer "spheres" can also be used to scatter UV and visible light radiation through this mechanism.At least one SPF booster can be selected from any SPF booster known in the art, including, for example, diethylhexyl syringylidene malonate; glass microhollow spheres, such as calcium aluminum borosilicate, sodium borosilicate, and calcium / sodium borosilicate; and copolymers of styrene and (meth)acrylic acid.

[0079] In certain embodiments, the sunscreen composition may further comprise at least one preservative. Suitable preservatives may include, but are not limited to, chlorphenesin, sorbic acid, disodium ethylenedinitrilotetraacetate, ethylhexylglycerin, phenoxyethanol, methylparaben, ethylparaben, propylparaben, phytic acid, imidazolidinyl urea, sodium dehydroacetate, benzyl alcohol, sodium benzoate, methylchloroisothiazolinone, methylchloroisothiazolinone, and mixtures thereof.

[0080] In certain embodiments, the sunscreen composition may further comprise at least one skin conditioning agent, which in certain embodiments may also function as a film former and / or emulsifier. Suitable skin conditioning agents include glycerin, such as ethoxylated glycerin and propoxylated glycerin; sugar alcohols, such as propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol, pentylene glycol, polypropylene glycol, polyethylene glycol, caprylyl glycol, sorbitol, hydroxypropyl sorbitol, erythritol, threitol, pentaerythritol, xylitol, glucitol, and mannitol; hexanetriol (e.g., 1,2,6-hexanetriol); glyceryl stearate; dimethicone; cyclomethicone; phenyl trimethicone; phenyl dimethicone; cetyl dimethicone; stearyl dimethicone; caprylyl methicone; amodimethicone; C30-45 alkyl dimethicone and methicone; cetearyl methicone; dimethicone copolyol; cyclopentasiloxane (e.g., Bentone Gel(TM); Dimethicone Crosspolymer; Dimethicone / Vinyl Dimethicone Crosspolymer; C30-45 Alkyl Cetearyl Dimethicone Crosspolymer; Cetearyl Dimethicone Crosspolymer; Dimethicone / Phenyl Vinyl Dimethicone Crosspolymer; Vinyl Dimethicone / Lauryl Dimethicone Crosspolymer; Trifluoropropyl Dimethicone / Trifluoropropyl Dimethicone Crosspolymer; Trimethylsiloxysilicate; Trisiloxane; Neopentyl Glycol Diheptanoate; Neopentyl Glycol Diethylhexanoate The cosmetic compositions may include, but are not limited to, glycerin, glycerin, sorbitan isostearate ...

[0081] In certain embodiments, the sunscreen composition may further comprise at least one film-forming agent. Suitable film-forming agents may include, but are not limited to, polyurethanes, acrylic acid / dimethicone crosspolymers, waxes, silicone acrylates, and mixtures thereof.

[0082] The sunscreen compositions disclosed herein can be prepared by any means known in the art, such as by mixing or blending the components of the composition in any manner accepted in the art. In certain embodiments, the sunscreen compositions can be prepared by incorporating the components into a commercially available topical carrier, which may contain other dissolved or dispersed ingredients, such as film-forming agents, surfactants, emulsifiers, thickeners, emollients, preservatives, pH adjusters, colorants, and fragrances. [Method of using the sunscreen composition]

[0083] Also disclosed herein is a method for reducing or preventing sunburn. The method disclosed herein may include topically applying an effective amount of the sunscreen composition disclosed herein to a body surface of a user, such as hair, skin, nails, or lips. As used herein, an effective amount can be any amount that reduces or prevents sunburn due to exposure to both UV radiation and visible light. In certain embodiments, the effective amount is, for example, about 0.5 mg / cm. 2 ~about 5mg / cm 2 , for example, about 1 mg / cm 2 ~about 3mg / cm 2 in the range of, or approximately 2 mg / cm 2 In certain embodiments, the methods disclosed herein further comprise allowing the sunscreen composition to dry after application. In certain embodiments, the sunscreen can be allowed to dry for a period ranging from about 5 minutes to about 30 minutes, e.g., about 10 minutes, about 15 minutes, about 20 minutes, or about 25 minutes.

[0084] By topically applying the sunscreen composition, it is understood to mean that the sunscreen composition can be applied to any surface of the user, including, for example, the skin, hair, nails, and / or lips. The sunscreen composition can be topically applied by any method known in the art, including by spraying, wiping, spreading, spreading, or rubbing by hand or with an applicator, such as a spray bottle, wipe, roller, or the like.

[0085] The effectiveness of the ability of sunscreen agents to block UV and / or visible light can be evaluated by any means known in the art. In certain embodiments, spectrophotometry, such as thin film spectrophotometry, can be used. For example, see Cole, C. et al., Evaluating sunscreen ultraviolet protection using a polychromatic diffuse reflectance device, PHOTODERMATOLOGY, PHOTOIMMUNOLOGY, & PHOTOMEDICINE 2019, 25(6):436-441. In certain embodiments, sunscreens can be evaluated using the U.S. Food and Drug Administration (FDA) critical wavelength test as described in the FDA Sunscreen Monograph: Labeling and Effectiveness Testing: Sunscreen Drug Products for Over-the-Counter Human Use. Federal Register 2011, 76:117, 35661-35665, and in certain embodiments, the ISO 24442 In Vitro Measurement of UVA Protection in Sunscreens and the ISO 24443 In Vitro UVA Protection Standard described in 2021 can be used. In certain embodiments, a spectroradiometer can be used for spectral scanning of the sunscreen using an illumination source, such as a solar simulator. The irradiance of the solar simulator can then be measured across the entire electromagnetic radiation spectrum, for example, from 290 nm to 800 nm, to arrive at a spectrophotometric measurement.

[0086] In certain embodiments, hybrid diffuse reflectance spectroscopy (HDRS) can be used to calculate the absorbance of sunscreen formulations. HDRS can be used to provide a measure of the protection provided to human skin in the UVA portion of the electromagnetic radiation spectrum. For example, HDRS measurements of formulations on human skin can be used to scale in vitro data to the appropriate amplitude by matching the calculated UVA protection factor (UVA-PF) of the in vitro spectrum with the UVA-PF value measured by HDRS. In certain embodiments, the visible light protection factor, which is similar to the SPF value but without biological weighting, can be calculated by measuring the reciprocal of the average transmittance value over a given wavelength range.

[0087] Disclosed herein is a method for increasing the visible light protection factor (VL-PF) of a sunscreen composition comprising at least one inorganic UV filtering agent and at least one inorganic pigment selected from iron oxides, comprising adding to the sunscreen composition at least one or at least two additional visible light protection agents, such as at least two visible light protection agents comprising barium sulfate and mica, wherein the at least one or at least two additional visible light protection agents are present in an amount effective to increase the visible light protection factor of the sunscreen composition. The VL-PF is similar to the SPF values described herein, but without biological weighting. The VL-PF can be calculated by any means known in the art. For example, in certain embodiments, the VL-PF can be calculated by measuring the reciprocal of the average transmission value over a given wavelength range, using, for example, the following formula:

number

[0088] In various aspects of the present disclosure, the VL-PF of the sunscreen compositions disclosed herein can be increased by an amount of at least about 0.1, such as at least about 0.2, at least about 0.3, at least about 0.4, at least about 0.5, at least about 0.6, at least about 0.7, at least about 0.8, at least about 0.9, or at least about 1.0, across a wavelength range spanning about 400 to 800 nm, e.g., about 400 to 600 nm or about 400 to 500 nm. In certain embodiments, the VL-PF of the sunscreen compositions disclosed herein can range from about 1 to about 5, such as about 1, about 1.5, about 2, about 2.5, about 3, about 3.5, about 4, about 4.5, or about 5.

[0089] Also disclosed herein is a method for increasing the SPF of a sunscreen composition, comprising adding at least one inorganic UV filtering agent, at least one inorganic pigment selected from iron oxides, and at least one or at least two visible light protection agents, such as barium sulfate and mica, to the sunscreen composition. SPF, or sun protection factor, can be measured by any means known in the art and described herein. In one embodiment, SPF can be measured according to the protocol established by the International Organization for Standardization (ISO) 24444:2019, which measures SPF in an indoor laboratory as the ratio of the amount of UV radiation required to produce erythema on sunscreen-protected skin to the amount of UV radiation required to produce erythema on unprotected skin. Because the standard described in ISO 24444:2019 defines SPF in terms of UV radiation (i.e., below 400 nm), it does not consider, and in fact excludes, the effects of real-world sun exposure, including the effects of visible light. In fact, laboratory-based SPF tests typically They use solar simulators that emit UV radiation only in the 290-400 nm region of the spectrum, while adding filters that filter out radiation below 290 nm and above 400 nm, significantly reducing the 380-400 nm content. Therefore, the effects of long-wavelength UVA and visible light on the skin are not considered in many SPF measurements, including indoor laboratory-based SPF measurements used in many commercially available sunscreen products.

[0090] In various embodiments of the method disclosed herein, SPF is determined based on actual outdoor sun exposure, and can be defined as the ratio of the minimum amount of sun exposure required to produce erythema on skin protected by sunscreen to the amount of sun exposure required to produce erythema on skin not protected by sunscreen.Therefore, SPF as used herein accounts for all the effects of actual outdoor sun exposure, including both UV radiation and visible light, and represents the performance of product under actual use conditions.

[0091] In various embodiments of the present disclosure, the SPF of the sunscreens disclosed herein, when tested under outdoor sunlight exposure conditions, can be increased by an SPF of at least about 3, e.g., at least about 4, at least about 5, or at least about 6, compared to sunscreen compositions not comprising an effective amount of at least one or at least two visible light protection agents. In certain embodiments, the SPF of the sunscreens disclosed herein, when tested under outdoor sunlight exposure conditions, can be increased to an SPF range of about 2 to about 10, e.g., about 3 to about 5, or about 3 to about 4. While this increase may appear small compared to SPF claims generated by indoor solar simulator test methods, in reality, the impact is proportionately much greater when compared to products tested under outdoor conditions, where the maximum SPF values observed for sunscreens claiming SPF 60-100 are in the range of 8-10. See, e.g., Hughes SNG, Lowe NJ, Gross K, Mark L, Goffe B, Hughes H, Cole C. Assessment of Natural Sunlight Protection Provided by 10 High SPF Broad Spectrum Sunscreens and Sun Protective Fabrics. Curr Probl Dermatol. 2021;55. In press. DOI: 10.1159 / 000517666. Thus, an increase of 2 to 6 SPF units beyond this observed maximum result of 8 to 10 under outdoor use conditions represents a significant improvement in actual protection.

[0092] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in its respective testing measurements. Moreover, all ranges disclosed herein should be understood to encompass any and all subranges subsumed therein.

[0093] While the present teachings have been described with respect to one or more implementations, changes and / or modifications can be made to the described examples without departing from the spirit and scope of the appended claims. Furthermore, while certain features of the present teachings may be disclosed singly with respect to some implementations, such features can be combined with one or more other features of other implementations as may be desirable or advantageous for any given or particular function. Furthermore, to the extent that the terms "including," "includes," "having," "has," "with," or variations thereof are used in either the detailed description or the claims, such terms are intended to be as inclusive as the term "comprising." Furthermore, in the discussion and claims herein, the term "about" indicates that a stated value may be slightly modified unless such modification results in non-compliance of the method or structure with the described embodiment. Finally, the term "typical" indicates that the description is used by way of example, rather than implying ideality.

[0094] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications, in which various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements may subsequently be made by those skilled in the art, which are also intended to be encompassed by the following claims. [Example]

[0095] [Example 1] Five anhydrous sunscreen stick compositions (0322A, 0211A, 0211B, 0211D, and 0314A) and one cream formulation (137-1216A) were prepared for evaluation and formulated as shown in Table 1 below.

[0096] [Table 1]

[0097] All formulations listed in Table 1 above further contained C12-15 alkyl benzoate, beeswax, butyloctyl salicylate, copernica cerifa (carnauba) wax, aluminum hydroxide or alumina, tocopheryl acetate, and triethoxycaprylylsilane. Control formulation #0322 and formulations 0211A, 0211B, 0211D, and 0314A were anhydrous stick base compositions further containing isohexadecane, caprylic / capric triglyceride, shea butter, triacontanyl PVP, and stearic acid. Formulation 137-1216A was a cream-based formulation further containing cyclopentasiloxane, ethylhexyl methoxycrylene, trimethylsiloxysilicate, PEG-10 dimethicone, cetyl silylated silica, disteardimonium hectorite, tetrahexyldecyl ascorbate, C10-30 cholesterol / lanosterol ester, propylene carbonate, hydrogen dimethicone, phenoxyethanol, and fragrance.

[0098] Sunscreen stick and cream formulations containing inorganic sunscreen filters and visible light blocking additives were evaluated for their ability to protect against both UV and visible light radiation.

[0099] In vitro UV-visible spectrophotometric evaluation from 290 to 800 nm: The UV and visible light absorption spectra of the sunscreen formulations in Table 1 were evaluated in vitro using conventional thin-film spectrophotometry methods similar to those used for the U.S. Food and Drug Administration (FDA) critical wavelength testing (FDA Sunscreen Monograph: Labeling and Effectiveness Testing: Sunscreen Drug Products for Over-the-Counter Human Use. Federal Register 2011, 76:117, 35661-35665) and the ISO 24443 in vitro UVA protection standard (ISO 24442 In Vitro Measurement of UVA Protection in Sunscreens, 2021).

[0100] Helioscreen HD6 polymethylmethacrylate (PMMA) plates were individually weighed, tared, and smeared with the test sunscreen composition and rubbed with a finger until a uniform film was formed, resulting in a total weight per unit area of 0.7 mg / cm 1 Two sunscreen-treated plates were prepared. Three blank PMMA plates coated with glycerin were prepared as controls.

[0101] An Optronics™ 756 spectroradiometer equipped with a 6-inch integrating sphere entrance port was used to spectrally scan the blank PMMA control plate and each sunscreen-treated plate. The illumination source was a Solar™ Light LS1000 solar simulator with a 9-inch diameter beam. The solar simulator's irradiance was measured from 290 nm to 800 nm, and the glycerin-treated control PMMA plate was first measured by placing it over the sphere integrator entrance input port to the spectroradiometer. Each sunscreen-treated plate was then measured in the same manner and position.

[0102] The absorbance of the sunscreen composition was calculated using the following equation: A=-log(I SS treated / I blank ) where A is the absorbance and I SS treatedis the irradiance of the solar simulator with a sunscreen-treated plate on the inlet port, and I blank is the irradiance of the solar simulator with a glycerin-treated control plate at the inlet port).

[0103] Hybrid Diffuse Reflectance Spectroscopy (HDRS): While the spectrophotometric measurements described above are suitable for measuring relative spectral shape or quality, the absolute amplitude of the absorbance curve may be sensitive to the uniformity of the formulation's spreading on the PMMA plate and the sunscreen's ability to form a uniform, continuous film on the plate's surface. Therefore, these measurements may not provide an accurate estimate of the absolute amplitude of the recorded absorbance curve. This is also why in vitro thin-film spectroscopy is not generally accepted for assessing the magnitude of sunscreen protection, and relative shape measurements, such as critical wavelength labeling, can be used instead.

[0104] The HDRS fills this gap, providing a measure of the absolute protection afforded in the UVA portion of the spectrum on human skin. HDRS measurements of the same formulation on human skin can then be used to scale the in vitro data to the appropriate magnitude by matching the calculated UVA Protection Factor (UVA-PF) of the in vitro spectrum to the UVA-PF value measured by HDRS.

[0105] In this example, HDRS measurements of the UVA-PF values of the test formulations listed in Table 1 were performed using a solar polychromatic HDRS device. The device irradiates the skin with UVA light, which then scatters within the epidermis and dermis. Some of the light is re-emitted from the skin, captured by a bundle of optical fibers on the device, and measured by a photomultiplier tube. The examples described herein were run first without sunscreen on the skin, then again with sunscreen applied and allowed to dry for 15 minutes. The UVA-PF of the sunscreen formulations was calculated using Equation 1 below: (Formula 1)

number

[0106] The UVA-PF of each formulation measured by HDRS was calculated similarly to the UVA-PF of the in vitro spectra described above. The in vitro spectra were scaled by multiplying the in vitro spectral absorbance (290–800 nm) by a single numerical factor, "s," to obtain UVA-PF values identical to those measured by HDRS. The results are shown in Figure 1, where the control sunscreen 0332A (containing titanium dioxide and 2.75% iron oxide but no barium sulfate, silica, bismuth oxychloride, or mica) had the lowest absorbance spectrum across the entire UV and visible wavelength range. The mica-containing stick formulation had the highest visible light-blocking absorbance, comparable to that of a visible light sunscreen containing 4.5% iron oxide. The mica-containing stick formulation had the highest visible light-blocking absorbance for wavelengths above 525 nm, even higher than that of a visible light sunscreen.

[0107] The Visible Light Protection Factor (VL-PF) was calculated by measuring the reciprocal of the average transmission value over a given wavelength range, using the following formula:

number

[0108] Table 2 below shows the calculated VL-PF for each of the six test formulations across the visible light spectrum in the ranges 400-500 nm, 400-600 nm, and 400-800 nm.

[0109] [Table 2]

[0110] Values can also be calculated as the percentage of visible light blocked by the sunscreen using the following formula, the results are shown in Table 3 below: Block % = (100 - (100 / VL PF ))%

[0111] [Table 3]

[0112] As shown in Tables 2 and 3 above, the addition of mica to iron oxide-containing formulations provided the highest visible light blocking capacity compared to the other inorganic pigments tested (i.e., barium sulfate, silica, and bismuth oxychloride), with the mica-containing formulations comparable to visible light sunscreens containing nearly twice the amount of iron oxide. Considering the entire visible light range of 400–800 nm, the mica-containing formulations exhibited the highest protection factor and highest visible light blocking percentage of all formulations tested, with barium sulfate performing second best. The bismuth oxychloride formulation with 4.4% mica and 3.9% bismuth oxychloride performed worse than any of the formulations tested and similar to the control formulation without any visible light blocking additives. Therefore, without wishing to be bound by theory, it appears that some incompatibility may exist between the mica and bismuth oxychloride mixtures.

[0113] HDRS SPF, UVA-PF, CW, and UVA1 / UV Calculations: Knowledge of the spectral shape of a sunscreen composition across the UV spectrum, combined with the HDRS measurement of UVA-PF, allows for a similar hybrid calculation to estimate a composition's SPF, UVA-PF, critical wavelength, and UVA1 / UV ratio. Using the calculation method described in the European Cosmetic Association HDRS test method (European Cosmetic Association Recommendation No. 26 for the use of alternative methods to ISO 14444: Annex II HDRS Method Protocol, March 23, 2022), the following SPF, UVA-PF, critical wavelength, and UVA1 / UV ratio were calculated for each formulation and are shown in Table 4 below.

[0114] [Table 4]

[0115] As shown in Table 4 above, the barium sulfate additive yielded significantly higher SPF and UVA-PF values compared to the 0322A control formulation, while the silica additive had a trend value of p > 0.05 but < 0.1. Mica exhibited the highest SPF but relatively low mid-UVA absorbance and the lowest UVA-PF. The mica additive exhibited longer UVA wavelength absorbance (380-390 nm), providing similar critical wavelength values to all other formulations tested and superior visible light protection.

[0116] The barium sulfate and silica additives increased both SPF and UVA-PF values compared to the 0322A control, while the bismuth oxychloride / mica formulation exhibited a similar SPF and a statistically higher UVA-PF. The visible light sunscreen exhibited the highest UVA-PF value, which may be due to the presence of 10% zinc oxide. The SPF measured by the HDRS was consistent with the actual static SPF of the visible light sunscreen tested in vivo (SPF 60).

[0117] From these experiments, it can be concluded that adding mica to titanium dioxide and iron oxide formulations provided the greatest increase in SPF and visible light protection, but not in UVA-PF. Barium sulfate and silica also significantly increased SPF, UVA-PF, and visible light protection. However, the combination of mica and bismuth oxychloride was not additive, providing only a slight improvement in UVA protection and no significant increase in visible light protection.

[0118] [Example 2] Anhydrous sunscreen stick formulations containing inorganic sunscreen filters and visible light protectants were evaluated for their ability to protect against both UV and visible light radiation. Experiments were also designed to evaluate the ability of barium sulfate and mica, both alone and in combination, to enhance visible light protection.

[0119] Test materials included 12 inorganic stick formulations and 1 organic sunscreen formulation. The 13 formulations are shown in Table 5 below.

[0120] [Table 5]

[0121] All of the formulations listed in Table 5 above, except for #11 (0923A), were anhydrous stick-based compositions and further contained C12-15 alkyl benzoate, beeswax, butyloctyl salicylate, copernica cerifa (carnauba) wax, aluminum hydroxide, tocopheryl acetate, triethoxycaprylylsilane, isohexadecane, caprylic / capric triglyceride, shea butter, triacontanyl PVP, and stearic acid.

[0122] In vitro UV-visible spectrophotometric assessment and HDRS at 290-800 nm: The UV and visible light absorption spectra of the sunscreen formulations listed in Table 5 above were evaluated in vitro using conventional thin-film spectrophotometry according to the method described in Example 1 above. HDRS measurements of the UVA-PF of the sunscreen formulations were performed using a solar polychromatic HDRS device as described in Example 1 above, and the UVA-PF of each formulation measured by HDRS was calculated as the UVA-PF of the in vitro spectrum. The in vitro spectra were scaled by multiplying the in vitro spectroscopic absorbance values (290-800 nm) by a single numerical factor, "s," to obtain UVA-PF values identical to those measured by HDRS, and the results are shown in Figures 2-4.

[0123] Figure 2 shows the full absorption spectra for Formulations 1-4 listed in Table 5. Control Formulation 1 contains a high titanium dioxide content and no zinc oxide or other additives. Formulations 2-4 contain lower amounts of titanium dioxide but 11% zinc oxide; Formulation 2 contains 7.5% barium sulfate and no mica; Formulation 3 contains 7% mica and no barium sulfate; and Formulation 4 contains 3.5% barium sulfate and 3.5% mica. As shown in Figure 2, Formulations 2 and 4 provided higher levels of visible light blocking than Formulation 1 in the visible light range of 400-500 nm. The formulation with only mica (Formulation 3) did not provide significant additive visible light protection, but when combined with barium sulfate at 3.5% each (Formulation 4), the protection was similar to that provided by Formulation 2, which contained 7.5% barium sulfate.

[0124] Figure 3 shows the total absorbance spectra for Formulations #5-7 listed in Table 5. As shown, when both barium sulfate and mica were included as visible light-blocking additives in Formulation #7, a synergistic combination was observed. Furthermore, improved UV absorption was observed within the visible light range, e.g., 400-550 nm for this formulation. The synergistic protection afforded by the combination of barium sulfate and mica was confirmed; while each additive by itself provided similar visible light protection at 5%, the combination of barium sulfate and mica at 2.5% each provided greater protection than either additive alone.

[0125] Figure 4 shows the full absorbance spectra for formulations #7-11, illustrating the dose-response relationship in protection afforded by iron oxide at decreasing amounts of 4.75% (#10), 2.75% (#7), 2.0% (#8), 1% (#9), 0.5% (#9a), and 0% (#9b). The increased visible light protection afforded by increasing amounts of iron oxide is compared to the lack of visible light protection observed with a sunscreen formulation containing only organic UV filters (#11). Thus, Figure 4 demonstrates that visible light protection is a function of iron oxide concentration.

[0126] Using the formulas set forth in Example 1, both the VL-PF and the percentage of visible light blocked by the sunscreen formulation were calculated and are shown below in Tables 6 and 7, respectively.

[0127] [Table 6]

[0128] [Table 7]

[0129] Figure 5 is a graph illustrating the dependence of VL-PF [blue light protection factor (400-500 nm)] on the iron oxide concentration in the formulation. In Figure 5, the first five data points (left to right) represent formulations #9b, 9a, 9, 8, and 7, all of which contain 2.5% barium sulfate and 2.5% mica, but with decreasing iron oxide content. As the amount of iron oxide in the formulation increases, the amount of blue light protection increases. The rightmost / top data point represents the predicted protection factor for a formulation containing 4.75% iron oxide, 2.5% barium sulfate, and 2.5% mica, based on a regression of the first five data points. The data point below the predicted protection factor data point is for formulation #10, which contains 4.75% iron oxide but no barium sulfate or mica. The difference between the predicted data point and that of formulation #10 is the estimated additional protection provided by the barium sulfate / mica combination, equivalent to an additional protection factor of approximately 0.4 protection factor units. Evaluating visible light protection explains that the primary protective element in the formulation is iron oxide, and that changing the iron oxide concentration from 4.75% to 0% reduces the blue light protection factor from 77% to 35%.

[0130] Figure 6 further demonstrates the synergistic combination of barium sulfate and mica for greater blue light protection in sunscreen formulations. Formulations #2, #3, and #4 demonstrate a slight increase in blue light protection with both barium sulfate and mica (#4, 3.17 at 400-500 nm) compared to barium sulfate alone (#2, 3.15 at 400-500 nm), and a slight increase in blue light protection with mica alone (#3, 2.36 at 400-500 nm). In particular, formulations #5, #6, and #7 demonstrate a synergistic increase in blue light protection with both barium sulfate and mica (#7, 3.65 at 400-500 nm) compared to either barium sulfate alone (#5, 2.35 at 400-500 nm) or mica alone (#6, 2.46 at 400-500 nm). This synergistic increase in protection is observed across the entire visible light spectrum from 400 to 800 nm.

[0131] Hybrid calculations were performed as described above in Example 1 to estimate the SPF, UVA-PF, critical wavelength, and UVA1 / UV ratio for each formulation tested. The calculations described in the European Cosmetic Association HDRS test method were used to calculate the results shown in Table 8 below.

[0132] [Table 8]

[0133] It should be noted that the calculated SPF and UVA-PF values for Formulation #11 are likely exaggerated because they do not include the effect of photostability on the expected SPF results. As shown in Table 8 and Figure 7, in addition to the other calculated Protection Factor values, the critical wavelength also depends on the iron oxide content, with increasing amounts of iron oxide resulting in a higher critical wavelength.

[0134] [Example 3] The UV and visible light blocking properties of individual ingredients used in stick and cream sunscreen formulations were evaluated. Twelve formulations containing individual sunscreen active ingredients were prepared, as described in Table 9 below.

[0135] [Table 9] [In vitro UV-visible spectrophotometric evaluation - 290~800nm]

[0136] The UV and visible light absorption spectra of 12 test sunscreen formulations were evaluated in vitro using conventional thin-film spectrophotometry similar to that used in the FDA critical wavelength test (FDA Sunscreen Monograph: Labeling and Effectiveness Testing: Sunscreen Drug Products for Over-the-Counter Human Use. Federal Register 2011, 76:117, 35661-35665) and the ISO 24443 in vitro UVA protection standard (ISO 24442 In Vitro Measurement of UVA Protection in Sunscreens 2021). Helioscreen HD6 polymethylmethacrylate (PMMA) plates were individually weighed, tared, and smeared with the test product and rubbed with a finger until a uniform film was formed, resulting in a total mass per unit area of 1.2 mg / cm. 1 Three blank control PMMA plates were prepared by coating with glycerin. An Optronics 756 spectroradiometer with a 6-inch integrating sphere inlet port was used to spectrally scan the control PMMA plate and each sunscreen-treated plate. Absorbance values were scanned from 290 to 450 nm using a Labsphere spectrophotometer. A baseline was measured from 290 to 800 nm on the glycerin-treated control PMMA plate, and then nine scans were performed on each sunscreen-treated PMMA plate. Absorbance was also measured across the upper UV and visible spectrum using the OL756 spectroradiometer by first measuring the output of a tungsten lamp through the glycerin-treated plate (baseline) and then through the sunscreen-treated plate. The following equation was used: A = -log(I SS treated / I blank )(where I SS treated is the irradiance of a tungsten lamp with a sunscreen-treated PMMA plate over the entrance port, and I blankAbsorbance was calculated using a 100-μm (where λ was the irradiance of a solar simulator using a glycerol-treated PMMA plate above the inlet port) method. Spectra from the two absorbance instruments were overlaid and normalized to a common wavelength range to give a continuous absorbance value from 290 to 700 nm. Noise "ripple" in the scan was smoothed with an exponential smoothing function.

[0137] Hybrid Diffuse Reflectance Spectroscopy (HDRS) - HDRS measurements of the UVA-PF of the test products were performed using a solar polychromatic HDRS device, and the UVA-PF was calculated using Equation 1 described in Example 1 above. Multiplying the in vitro spectroscopic absorbance values (290-800 nm) by a single numerical factor "s" scaled the in vitro spectra to obtain a UVA-PF identical to that measured by HDRS, yielding an absolute absorbance spectrum. Figure 8 shows the absorbance characteristics of mica and barium sulfate additives. Note that in Figure 8, when subtracting the 4.4% TiO absorbance from the mica + 4.4% TiO spectrum, the resulting absorbance of mica itself is practically zero across the entire spectrum. 5% barium sulfate has very low absorbance values, averaging approximately 0.1 AU across the spectrum. These data show that the highest contribution from BaS is 0.1 AU, while the contribution from mica is zero across the spectrum. However, when combined in a complete formulation (e.g., Formulation #7 in Example 1 above), visible light protection was synergistically higher than either alone at a 5% concentration. Without wishing to be bound by theory, the explanation for this may lie in the physical interaction of BaS and mica+TiO2 with nano-TiO2 and ZnO in the complete formulation, resulting in better separation of the cluster particles and more complete coverage of the particles on the skin.

[0138] Example 4 - Natural Light SPF Test of Four Sunscreens in Arequipa, Peru

[0139] Four different sunscreen formulations were SPF tested under natural tropical midday sunlight. Testing was performed using a method similar to that used in the FDA Sunscreen Final Rule, except natural sunlight was used instead of a solar simulator.

[0140] subject: Ten subjects with Fitzpatrick skin types I (2 subjects), II (6 subjects), and III (2 subjects) participated in the study; none were pregnant, had a history of skin cancer, or were otherwise ineligible.

[0141] Sun exposure and conditions: Erythema effective energy 3942+ / -5J / m 2 (17.8 times the minimal erythema dose (MED) or 37.6 SED for Type II individuals) and UVA 60.3 + / - 1 J / cm of outdoor natural light in Arequipa, Peru (7800' elevation, 16° south latitude) for 170 minutes centered at solar noon on a cloudless day with global solar radiation. 2 Subjects were exposed to sunlight. Temperature and humidity during the test period ranged from 70° to 71° with a dew point of 17° to 37° (low humidity), approximating clinical laboratory conditions. Solar zenith angle ranged from 75° to 87.6° during the exposure period.

[0142] Test products: Four stick products were formulated containing 12.5% titanium dioxide and 10.8% zinc oxide as the primary sunscreen active ingredients. The formulations also contained various concentrations of iron oxide ranging from 0 (control) to 4% (dark), as listed in Table 10 below.

[0143] [Table 10]

[0144] The sticks are heated to a liquid state, and the product is applied at a concentration of 2 mg / cm 2 The sunscreens were pipetted onto the skin at a density of 100 mg / mL and allowed to dry for at least 15 minutes. An aluminum-laminated template was attached to each subject's back, and both the control and test sunscreens were applied to define circular exposure areas. The remainder of the back, legs, arms, and head were covered with sun-protective clothing and a hat. Each group of subjects was exposed to the sun simultaneously.

[0145] Subjects were exposed to the sun at noon, centered at solar noon, for up to 170 minutes. Subjects were instructed to lie as still as possible with their backs facing the sun. Aluminum tape was used to cover the test site based on a predetermined sun exposure dose (erythema-weighted UVB dose). Sunburn UV and UVA intensities were measured every minute and calculated as the cumulative dose over the entire exposure period using a Solar Light model PMA2100 radiometer equipped with a PMA2101 erythema sensor and a PMA2110 UVA sensor. During the first 45 minutes, 25% of the unprotected control site was covered at predetermined intervals to determine the minimum unprotected erythema and tanning doses. The sunscreen-treated exposed site was also covered with a predetermined amount to estimate the minimum erythema and tanning doses for the protected site.

[0146] evaluation: Trained, unbiased scorers, blinded to treatment location (except for the unprotected MED), evaluated the unprotected and protected skin sites for erythema and PPD sun reactions the following morning, 16 to 24 hours after sun exposure. Erythema and persistent pigmentation reactions were scored separately. To distinguish between the two reactions, light pressure was applied to the test site if both were present. If no difference was observed between the sites, the reaction was persistent pigmentation only. If blanching was also observed, erythema was scored. If only erythema was observed, persistent pigmentation was scored as 0.

[0147] The following erythema rating scale was used: 0 = no perceptible erythema or PPD 0.5 = vague erythema or PPD with poorly defined borders 1 = Clear erythema or PPD with well-defined borders (MEDu or PPD-Pfu) 2 = Highly visible erythema or PPD 3 = Severe erythema or PPD with edema

[0148] After 16-24 hours of sun exposure, protected and unprotected skin sites were assessed and photographed. Eight unprotected skin sites were viewed in a vertical row on the left side of each subject's back. Four sunscreen test areas (30 cm) were used. 2 ) were located to the right of or immediately below the unprotected site, respectively. When a given cumulative erythema-weighted UV dose was recorded using a calibrated radiometer, each of the six sunscreen sites was progressively covered from the lower left to the lower right, then from the upper left to the upper right, based on the principal investigator's instructions. The erythema response for each sunscreen site progressed in order of redness (erythema) based on cumulative sun exposure. The scoring results are shown in Table 11 below.

[0149] [Table 11]

[0150] All formulations were not statistically significantly different from each other, but the light, medium, and dark formulations were statistically significantly different from the control (p<0.05). Surprisingly, the median value for the medium shade, which also contained mica and barium sulfate and 2.75% iron oxide, was higher than the dark shade product, which contained a higher 4.00% iron oxide content.

[0151] The SPF was calculated by dividing each subject's unprotected MED by the MED protected by sunscreen. For subjects with no erythema reaction at the highest dose, the highest protected MED was used to calculate the minimum SPF value. Due to the lack of available area on the subject's back, the SPF was not determined for the control formulation; only the highest exposure dose was evaluated as described above. The results are shown in Table 12 below.

[0152] [Table 12]

[0153] While SPF values may appear lower compared to currently available products, this discrepancy may be due to the light source used to test commercial products. Commercial products are tested using a simulated sunlight source that is devoid of long-wavelength UVA1 and completely devoid of visible light. Previous testing has shown that FDA and ISO Standard P2 sunscreens (with an SPF of 16.3 in simulated sunlight clinical testing) only have an SPF of 4.5 in natural sunlight.

[0154] Similarly, the ISO standard P8.5 sunscreen (SPF 63 in simulated sunlight clinical testing) only achieves an SPF of 8 in natural light under conditions similar to those reported in this example. Therefore, achieving an SPF greater than SPF 10 in natural light is unusual and noteworthy. This difference is due to the erythemal contribution to the erythemal response from the long-wave UVA and visible light portions of natural light that are not protected against using UV-only filters.

[0155] Similar to SPF for erythema protection, the Pigment Darkening Protection Factor (PPD-PF) provides similar protection against skin pigmentation (sunburn). PPD-PF is the ratio of the minimum dose required to induce a visible pigmentation response in unprotected skin 24 hours after exposure divided by the minimum dose required for visible pigmentation in sunscreen-protected skin at the same time point. This is similar to UVA-PF, which is clinically tested using only UVA radiation, but in this case, the entire solar spectrum is utilized, including UVB, UVA, and visible (and IR) radiation.

[0156] The PPD-PF of the subjects was calculated and the results are shown above in Table 12. Statistical analysis using Student's T-test showed that there was no significant difference between the dark and medium formulations (p=0.17), but there was a statistical difference both between the medium and light formulations and between the dark and light formulations (p=<0.015 and p<0.01, respectively).

[0157] Demonstration of visible light protection of test formulations: To demonstrate that the difference in protection was due to the visible portion of natural light, additional subjects were tested and a CGA 400 long-pass filter was placed over the sunscreen-protected areas, blocking all ultraviolet radiation below 400 nm and allowing only visible and infrared light to irradiate the sunscreen-protected skin. Therefore, any discernible difference in protection by the test formulations would be due to differences in visible light protection. To demonstrate this, intermediate and control test formulations were selected.

[0158] The intermediate and control formulations were applied to the skin at two separate but adjacent sites (diagonally opposite each other), and each subject showed a stronger and more visible reaction in the site treated with the control formulation than in the site treated with the intermediate formulation.

[0159] Example 5 - Evaluation of Sunscreen Visibility on Skin The purpose of the evaluation was to assess the visibility of the sunscreens on the skin using instrumental evaluation. The results show that the sunscreen containing a combination of mica and barium sulfate was less visible on the skin at 2.75% iron oxide compared to the sunscreen with no mica or barium sulfate but with 4.5% iron oxide, but nevertheless, both compositions provided similar visible light protection.

[0160] Test sites on human skin included the dorsal forearm (darkest), volar, and upper thigh (lightest). Three sites with different background colors were measured before and after sunscreen application using a CR-400A Skin Reflectance Spectrometer using the L a*b color space. A controlled application density of 2 mg / cm was applied to the skin test sites. 2 The sunscreen was applied at 100°C and the change in visibility was calculated using the formula for ΔE.

number

[0161] The following five formulations were evaluated, as shown in Table 13 below:

[0162] [Table 13]

[0163] Photographs of the test sites revealed that Formulation #2 most closely resembled the subject's background skin and had the lowest calculated visibility after sunscreen application. A ΔE value was calculated for each of the five formulations. The lower the calculated ΔE value, the less change in visibility after sunscreen application compared to unprotected skin. Each formulation was statistically different (p<0.05) from the other formulations at the three test sites. The ΔE values for each of the three test sites are shown in Table 14 below.

[0164] [Table 14]

[0165] The results show that the addition of mica and barium sulfate to 2.75% iron oxide (Formulation #4) improved visibility compared to a formulation with the same iron oxide content but no mica or barium sulfate (Formulation #3). Nevertheless, although Formulation #4 had lower visibility compared to Formulation #5, it still provided comparable sunscreen protection as Formulation #5, as shown in the above examples involving outdoor sunscreen testing.

Claims

1. A sunscreen composition for use in a method of reducing or preventing photodermatitis caused by visible light and ultraviolet (UV) radiation in a subject, wherein the sunscreen composition is (a) at least one inorganic UV filtering agent selected from zinc oxide or titanium dioxide, (b) at least one inorganic pigment selected from iron oxides, (c) at least two visible light protective agents comprising barium sulfate and mica, Includes, The aforementioned at least two visible light protective agents are present in amounts effective in reducing or preventing photodermatitis caused by visible light. The aforementioned at least two inorganic UV filtering agents are present in a total amount of about 10% to about 30% by weight relative to the total weight of the sunscreen composition. A sunscreen composition comprising the above-mentioned at least two visible light-blocking agents in a total amount of about 1% to about 10% by weight relative to the total weight of the sunscreen composition.

2. The sunscreen composition according to claim 1, comprising zinc oxide and titanium dioxide.

3. The sunscreen composition according to claim 1, wherein it is an anhydrous substance.

4. The sunscreen composition according to claim 1, wherein at least one of the at least two visible light protective agents further comprises a silica coating.

5. The sunscreen composition according to claim 1, wherein the iron oxide is selected from the group consisting of black iron oxide, brown iron oxide, red iron oxide, yellow iron oxide, and mixtures thereof.

6. The sunscreen composition according to claim 1, wherein the iron oxide is present in the sunscreen composition in a total amount ranging from about 0.1% by weight to about 5% by weight relative to the total weight of the sunscreen composition.

7. The sunscreen composition according to claim 1, wherein the iron oxide is present in the sunscreen composition in a total amount ranging from about 1% by weight to about 3% by weight relative to the total weight of the sunscreen composition.

8. The sunscreen composition according to claim 1, wherein the barium sulfate is present in an amount ranging from about 0.1% to about 5% relative to the total weight of the sunscreen composition.

9. The sunscreen composition according to claim 1, wherein the mica is present in an amount ranging from about 0.1% to about 5% of the total weight of the sunscreen composition.

10. The sunscreen composition according to claim 1, wherein at least one of the inorganic UV filtering agents is titanium dioxide, and the titanium dioxide has an average particle size in the range of about 5 nm to about 20 nm.

11. The sunscreen composition according to claim 10, wherein at least one of the inorganic UV filtering agents is zinc oxide, and the zinc oxide has an average particle size in the range of about 10 nm to about 100 nm.

12. The sunscreen composition according to claim 1, which does not contain an organic UV filtering agent.

13. A method for increasing the visible light protection index (VL-PF) of a sunscreen composition comprising at least one inorganic UV filtering agent selected from zinc oxide or titanium dioxide and at least one inorganic pigment selected from iron oxide, comprising the step of adding at least two visible light protective agents comprising barium sulfate and mica to the sunscreen composition, wherein the at least two visible light protective agents are present in the sunscreen composition in an amount effective to increase the VL-PF across the entire electromagnetic wavelength spectrum in the range of about 400 nm to about 800 nm. The aforementioned at least two inorganic UV filtering agents are present in a total amount of about 10% to about 30% by weight relative to the total weight of the sunscreen composition. A method wherein the at least two visible light-blocking agents are present in a total amount of about 1% to about 10% by weight relative to the total weight of the sunscreen composition.

14. The method according to claim 13, wherein the electromagnetic wavelength spectrum is in the range of about 400 nm to about 500 nm.

15. The method according to claim 13, wherein the visible light blocking index increases by at least about 0.

5.

16. A sunscreen composition, (a) at least one inorganic UV filtering agent selected from zinc oxide or titanium dioxide, (b) at least one inorganic pigment selected from iron oxides, (c) at least two visible light protective agents comprising barium sulfate and mica, Includes, The aforementioned at least two visible light protective agents are present in amounts effective in reducing or preventing photodermatitis caused by visible light. The aforementioned at least two inorganic UV filtering agents are present in a total amount of about 10% to about 30% by weight relative to the total weight of the sunscreen composition. A sunscreen composition comprising the above-mentioned at least two visible light-blocking agents in a total amount of about 1% to about 10% by weight relative to the total weight of the sunscreen composition.

17. The sunscreen composition according to claim 16, wherein it is an anhydrous substance.

18. The barium sulfate is present in an amount ranging from about 0.1% to about 5% of the total weight of the composition. The sunscreen composition according to claim 16, wherein the mica is present in an amount ranging from about 0.1% to about 5% of the total weight of the sunscreen composition.

19. The sunscreen composition according to claim 16, which does not contain an organic UV filtering agent.

20. Furthermore, the sunscreen composition according to claim 16, comprising at least one antioxidant, preferably the at least one antioxidant selected from the group consisting of vitamin E or its derivatives and vitamin C or its derivatives.

Images