Sunscreen compositions with functionalized zeolite spf boosters

Abstract

The present invention relates to a sunscreen composition for protection against ultraviolet (UV) light damage comprising an SPF booster based on a specific zeolite functionalized with silane moieties.

Description

Technical Field

[0001] This invention generally relates to sunscreen compositions for protecting against damage from ultraviolet (UV) rays. More specifically, this invention relates to sunscreen formulations having an SPF synergist based on a specific zeolite functionalized via a silane moiety.

[0002] describe

[0003] It is generally believed that exposure to ultraviolet (UV) light with wavelengths from about 200 nm to about 400 nm has negative effects. Prolonged, unprotected exposure to solar radiation leads to adverse health consequences, such as immediate painful sunburn, and long-term damage that can cause serious conditions such as skin cancer.

[0004] Ultraviolet light also accelerates aging by inducing the formation of free radicals in the skin. Free radicals include, for example, singlet oxygen, hydroxyl radicals, superoxide anions, nitric oxide, and hydrogen radicals. Free radicals attack DNA, membrane lipids, and proteins, generating carbon radicals. These then react with oxygen to produce peroxy radicals, which can attack neighboring fatty acids to generate new carbon radicals. This cascade leads to a chain reaction, resulting in lipid peroxidation products. Damage to cell membranes leads to loss of cell permeability, increased intercellular ion concentration, and reduced ability to excrete or detoxify products.

[0005] Different sunscreen compositions can be used to reduce the amount of solar UV radiation received by the skin during exposure to solar radiation.

[0006] Sunscreen compositions may contain inorganic UV filters (also known as physical filters) and / or chemical UV filters (which are organic molecules). Inorganic UV filters interact with UV light through two mechanisms: absorption and reflection / scattering, while organic filters typically contain aromatic carbons and / or other electronically dense bonds responsible for absorbing light in the UV range of the solar spectrum.

[0007] The higher the amount of UV filter, the greater the level of UV protection. However, it has recently become clear that excessively high concentrations of both inorganic and organic UV filters not only compromise the aesthetics of sunscreen products but also pose adverse safety risks to both human health and the environment.

[0008] Therefore, a key challenge in this field is to reduce the amount of UV filters used in sunscreen formulations while still ensuring high sun protection efficacy.

[0009] Accordingly, an effective strategy for addressing this problem involves using sun protection factor (SPF) enhancers in sunscreen formulations. SPF enhancers are defined as compounds that are safe for both human use and the environment, are not considered active sunscreen ingredients, but serve to increase the SPF of compositions in which they are incorporated.

[0010] Typical sunscreen formulations are emulsions, serums, creams, or gels, and contain many other compounds in addition to chemical and / or physical UV filters, such as emulsifiers, solubilizers, stabilizers, preservatives, and SPF enhancers; all of these affect the protective properties of the sunscreen, the activity of the SPF enhancer, and the cosmetic appeal.

[0011] As reported in WO2017112982 and WO2021102873, a widely used inorganic SPF synergist is represented by hydrophobic silica particles, which are also in the form of silica particles with a surface treated with a silanizing agent. US9265715 claims protection for, for example, the use of silica particles in combination with nylon particles and barium sulfate particles to enhance the effect of sunscreen compositions. Another example is represented by US20210330571, in which hydrophobic fine particles of titanium dioxide or zinc oxide ensure the synergistic effect of the final composition. Alternatively, WO2022081942 describes an organic compound, specifically celecoxib, as an SPF synergist in combination with chemical UV filters.

[0012] However, some of the most frequently cited compound classes, such as silica, have been gradually phased out due to their toxicity to humans and the environment. Inorganic compounds such as titanium dioxide and zinc oxide, or organic compounds such as celestin reported above, cannot be considered SPF enhancers because they act as true UV filters (the so-called SPF doping effect).

[0013] Therefore, the object of the present invention is a sunscreen composition comprising at least one UV filter and at least a specific type of zeolite selected from β-type zeolite, ZSM-5 type (MFI), Linde type (LTA), mordenite type (MOR), or octahedral zeolite type (FAU), wherein the zeolite is functionalized with the silane portion selected from thiethoxycaprylyl silane, stearyltriethoxysilane, trimethylol silane, and methoxypoly(ethyleneoxypropyltrimethoxysilane).

[0014] In particular, the inventors have discovered that the specifically functionalized zeolite (which does not exhibit sunscreen activity as a single component) acts as an effective SPF enhancer when formulated into sunscreen formulations containing UV filters, thereby avoiding the SPF dopant effect according to international safety regulations.

[0015] Furthermore, it has been clearly stated that the functionalization of the zeolite and the resulting amphiphilic properties improve its dispersibility in both single-phase and two-phase formulations and reduce aggregation in the final formulation, resulting in a significant increase in SPF synergistic effect. In fact, as reported in the Experimental Section below, the specific zeolite ensures a synergistic effect of at least 20% on the SPF of the final composition.

[0016] The SPF enhancer has also been shown to be compatible with marine-friendly UV filters and other marine-friendly sunscreen components, as well as with water-resistant components used in water-resistant sunscreen formulations.

[0017] In a preferred embodiment, the zeolite is characterized by the presence of ammonium or hydrogen as counterions at the ion exchange sites of the framework structure, and a pH range of 3.0 to 8.0.

[0018] On the other hand, zeolite is characterized by a particle size distribution of 0.1 µm to 15 µm, preferably 0.2 µm to 5.0 µm.

[0019] The functionalization of the zeolite is carried out with a silane selected from triethoxyoctylsilane, stearyltriethoxysilane, trihydroxymethylsilane or methoxypolyethyleneoxypropyltrimethoxysilane, wherein the amount of silane is 0.2% to 10.0%, preferably 2.0% to 6.0%, relative to the total weight of the zeolite.

[0020] According to the present invention, the amount of zeolite is from 0.1% to 5.0% by weight, preferably from 1.0% to 3.0% by weight, relative to the total weight of the composition; and the amount of UV filter is from 1.0% to 35% by weight, relative to the total weight of the composition.

[0021] In a preferred embodiment, specifically when an organic UV filter is used, the amount of the compound is 1% to 15% by weight relative to the total amount of the composition, while when the filter is an inorganic compound, the amount is preferably 1% to 35% by weight relative to the total amount of the composition.

[0022] In fact, the UV filter used in the sunscreen composition described herein can be an organic molecule (also defined as a chemical filter), an inorganic compound (also defined as a physical filter), or a mixture thereof.

[0023] The organic molecules are selected from: octylene, ethylhexyl salicylate, homosalate, butyl methoxydibenzoylmethane, diethylaminohydroxybenzoylhexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazine ketone, avobenzone, diethylhexylbutamidotriazine ketone, ethylhexyl methoxycinnamate, phenylbenzimidazole sulfonic acid, tri-biphenyl triazine, tri-biphenyl triazine (nano), oxybenzone, octinoxate, octyl triazine ketone, octyl Salicylate, Pardimethicone O, Bis-piperazine HAA299, Bis-piperazine HAA299 (nano), (2-ethoxyethyl(2Z)-2-cyano-2-[3-(3-methoxypropylamino)cyclohex-2-en-1-yl]acetate), Sulphone, Cresoltrazol trisiloxane, Methylene bis-benzotriazolyl tetramethylbutylphenol, Benzyl camphor sulfonic acid, 4-methylbenzylidene camphor, Polysiloxane-15, Sodium Sulphone, Aminobenzoic acid, PEG-25 PABA, methylene bis-benzotriazolyltetramethylbutylphenol, methylene bis-benzotriazolyltetramethylbutylphenol nano, menthyl anthranilate, isopentyl-4-methoxycinnamate, terephthalimide dicamphor sulfonic acid, dioxibenzone, cinoxazone, camphor benzalkonium sulfate and mixtures thereof, can be considered for all size ranges of nanoscale, submicron and micron, including modification by any means (via chemical or physical methods).

[0024] The inorganic compounds are selected from zinc oxide, anatase titanium dioxide, rutile, titanium dioxide and mixtures thereof, and can take into account all size ranges from nanometer to submicrometer to micrometer.

[0025] As reported above, the SPF enhancers described herein are highly versatile and compatible with a variety of matrices, and therefore, according to the present invention, the final sunscreen composition can be formulated as a single-phase formulation (e.g., a gel or stick) or as a two-phase formulation (e.g., a homogeneous oil-in-water emulsion, such as a serum or cream).

[0026] The sunscreen composition according to the present invention may further comprise at least one of the following: cosmetically acceptable emollients, carriers, pigments, humectants, vitamins, antioxidants, emulsifiers, co-emulsifiers, hydrophilic or hydrophobic thickeners, waxes, lipids, film-forming agents, organosilicones, surfactants, activators, extracts, fragrances, preservatives, pH adjusters, suspending agents, and chelating agents.

[0027] The present invention also relates to compositions according to any embodiment disclosed herein, which serve as sunscreen compositions or sunscreen agents. In particular, the present invention relates to compositions according to any embodiment disclosed herein, which are used in methods for protecting stratum corneum surfaces (e.g., skin) from UV radiation, the methods comprising contacting the stratum corneum surface with the sunscreen composition of the present invention.

[0028] The present invention also relates to compositions as disclosed herein, used as additives or excipients in sunscreen compositions. Furthermore, the present invention relates to zeolites or functionalized zeolites as disclosed herein, particularly selected from β-type, ZSM-5 type (MFI), Linde type (LTA), mordenite type (MOR), and octahedral zeolite type (FAU), said zeolites being functionalized with the silane portion selected from triethoxyoctylsilane, stearyltriethoxysilane, trimethylolsilane, or methoxypoly(ethyleneoxypropyltrimethoxysilane), said zeolites being used as excipients in sunscreen compositions or for enhancing the SPF effect of UV filters in sunscreen compositions.

[0029] Surprisingly, the SPF synergistic effect was achieved by the compositions and / or functionalized zeolites of the present invention without the zeolite being bound to the filter (e.g., without absorption or encapsulation). In fact, according to the present invention, the zeolite and UV filter do not interact, but only form a physical mixture. As demonstrated by SEM images (FESEM – EDS (Supra 55VP / Zeiss + UltraMax 170mm² / Oxford Instruments)), the zeolite is not integrated into and is not part of the UV filter, and does not act as a carrier according to the present invention. As will become apparent from the following experimental section, the zeolite according to the present invention actually has a synergistic effect. This is also confirmed by the fact that, in the absence of a UV filter, the zeolite of the present invention does not function as a sunscreen filter.

[0030] As will be apparent to those skilled in the art, the compositions of the present invention can be included in a variety of articles and products, such as leave-in lotions and creams, shampoos, conditioners, shower gels, toilette bars, antiperspirants, deodorants, shaving creams, lipsticks, lip balms, stick formulations, foundations, sunscreens, etc. It should be noted that sunscreen agents are only active upon exposure to UV radiation. In cases where protection against UV radiation / sunburn is not required, such as when the composition is used as a shower gel, applying the composition to the skin cannot be considered a therapeutic treatment, and the composition is primarily intended for use as a cosmetic rather than a pharmaceutical.

[0031] Therefore, the present invention also relates to non-therapeutic uses of compositions according to any embodiment disclosed herein, such as cosmetic uses.

[0032] Other aspects and advantages of the invention will become apparent from the following experimental section.

[0033] Example

[0034] The invention will now be described in more detail with reference to the following non-limiting embodiments. It will be apparent to those skilled in the art that modifications or variations of the embodiments illustrated herein are covered by the appended claims.

[0035] Comparative sunscreen compositions and the sunscreen compositions of the present invention, incorporating the ingredients listed in Tables 1 and 2, were prepared according to the following methods, and their SPF values ​​were compared.

[0036] Manufacturing process of oil-in-water creams (B1, S1, S2, C1):

[0037] 1. Weigh the components of phase A and heat them to 75°C to 80°C with stirring.

[0038] 2. When the temperature is reached, add phase B and homogenize with UltraTurrax at at least 3500 rpm for 5 minutes.

[0039] 3. Weigh the components of phase C and heat them to 75°C to 80°C with stirring.

[0040] 4. When both the emulsifier and the UV filter are completely dissolved, add phase D and continue mixing until the SPF synergist is completely incorporated into phase C.

[0041] 5. When phases A+B and C+D are homogeneous and at their specified temperatures, add phase C+D to phase A+B and homogenize using UltraTurrax at 4000 rpm for 10 minutes.

[0042] 6. Cool to room temperature with gentle stirring, then add the components of phase E one at a time.

[0043] 7. If necessary, adjust the pH to 5.5 to 6.5 with citric acid.

[0044] Table 1: Examples of inventions and comparative examples of oil-in-water formulations

[0045]

[0046] Manufacturing process of rod-shaped formulations (B2, S3):

[0047] 1. Combine and mix the reagents of phase A together, and heat to 80°C to 85°C until fully melted and homogeneous.

[0048] 2. Individually, mix all the reagents of phase B together and heat to 80°C to 85°C until fully melted and homogeneous.

[0049] 3. Add phase B to phase A and stir until homogeneous.

[0050] 4. Remove it from the heat source and mix it with the pre-blended phase C.

[0051] 5. Pour it out while it is still molten.

[0052] Table 2: Examples of inventions and comparative examples of rod-shaped formulations

[0053]

[0054] Manufacturing process of rod-shaped formulations (B3, S4, S5, C2, C3):

[0055] 1. Combine and mix the reagents of phase A together, and heat to 80°C to 85°C until fully melted and homogeneous.

[0056] 2. Individually, mix all the reagents of phase B together and heat to 80°C to 85°C until fully melted and homogeneous.

[0057] 3. Add phase B to phase A and stir until homogeneous.

[0058] 4. Remove it from the heat source and mix it with the pre-blended phase C.

[0059] 5. Pour it out while it is still molten.

[0060] Table 3: Examples of inventions and comparative examples of rod-shaped formulations

[0061]

[0062] SPF in vitro assessment

[0063] An internal-to-external method has been developed to calculate the SPF of sunscreen products against radiation that causes erythema. 体外 The protection factor (SPF) 体外 The value is calculated based on a set of standard sunscreens calibrated.

[0064] This method is based on the principles recommended by the European Cosmetics and Fragrance Association (formerly Colpa, now Cosmetics Europe) in 2011 (known as the "In vitro SPF Double Plate method"), with internal modifications. Therefore, the calculated protection factor is an internal value used for comparison with samples and may not be directly comparable to fully regulated in vivo testing.

[0065] This test is based on the assessment of UV transmittance through a sunscreen sample film spread on a rough PMMA (poly(methyl methacrylate)) substrate. In a heuristic procedure, exposure to radiation from a UV exposure source is required. In this method, UV exposure is not used; each set of sunscreen transmittance data is mathematically corrected so that the in vitro SPF data produce the same SPF values ​​as provided by several certified SPF standards.

[0066] The absorbance A property of the sunscreen agents on the test panel was measured using a Perkin-Elmer LAMBDA 1050+UV / Vis / NIR spectrophotometer equipped with a 150 mm Perkin-Elmer LAMBDA integrating sphere, and the SPF was calculated using the absorbance values ​​through the following integral formula:

[0067]

[0068] in:

[0069] E: CIE-1987 erythema response spectra listed in the table;

[0070] I: Global irradiance at midday summer at 40° North latitude listed in the table;

[0071] A: Measured absorbance;

[0072] C: Correction coefficient

[0073] The wavelength range of the UV spectrophotometer should span the main band of 290 nm to 400 nm, covering both the ranges of 290 nm to 320 nm (UV-B) and 320 nm to 400 nm (UV-A) required for SPF calculations.

[0074] A correction factor is used in the calculation to improve SPF. 体外 = SPF i，标准品 i = P1, P2, P3 (certified standard products with different sun protection ranges, see the table below for certification values).

[0075]

[0076] The wavelength range of the UV spectrophotometer should span the main band of 290 nm to 400 nm, covering both the range of 290 nm to 320 nm (UV-B) and 320 nm to 400 nm (UV-A).

[0077] The average SPF improvement (%) calculated as follows is reported in the table below:

[0078]

[0079] in:

[0080] SPF B SPF measured in sample formulations containing UV filters and UV enhancers

[0081] SPF F SPF measured for sample formulations containing UV filters

[0082] SPF P SPF measured in placebo formulation (without UV filters and UV enhancers)

[0083] The in vitro results for both the oil-in-water formulation and the stick formulation are reported in the table below.

[0084]

[0085] Table 4

[0086] Table 4 clearly shows that the presence of SPF synergists based on zeolite, specifically zeolite functionalized via a silane moiety according to the present invention, contributes to significantly enhanced UVB performance.

[0087] In fact, compared to the reference composition without any SPF synergist system, UVB performance was improved by more than 40% when triethoxyoctylsilane-functionalized ZSM-5 zeolite was used as the SPF synergist in both the stick and cream formulations (see S1 to S3). Furthermore, compared to the reference composition (B3) without any SPF synergist system, UVB performance was improved by more than 200% when triethoxyoctylsilane-functionalized β-type zeolite was used as the SPF synergist in the stick formulation (see S4 to S5).

[0088] Conversely, as disclosed in Comparative Examples C1 to C3, the same zeolite particles without silane functionalization do not achieve the same synergistic effect.

Claims

1. A sunscreen composition comprising: a) at least one UV filter; and b) Zeolite as an SPF synergist The zeolite is selected from β-type, ZSM-5 type (MFI), Linde type (LTA), mordenite type (MOR) and octahedral zeolite type (FAU), and the zeolite is functionalized with the silane portion selected from triethoxyoctylsilane, stearyltriethoxysilane, trimethylol silane or methoxypoly(ethyleneoxypropyltrimethoxysilane).

2. The composition according to claim 1, wherein the zeolite contains ammonium or hydrogen as counterions at the ion exchange sites of the framework structure.

3. The composition according to claim 1 or 2, wherein the particle size distribution is from 0.1 µm to 15 µm, preferably from 0.2 µm to 5.0 µm.

4. The composition according to any one of the preceding claims, wherein the amount of zeolite is from 0.1% to 5.0% relative to the total weight of the composition.

5. The composition according to any one of the preceding claims, wherein the amount of silane is 0.2% to 10.0%, preferably 2.0% to 6.0%, relative to the total weight of the zeolite.

6. The composition according to any one of the preceding claims, wherein the UV filter is an organic UV filter, and the amount of the organic UV filter is from 1% to 15% by weight relative to the total amount of the composition.

7. The composition according to claim 7, wherein the UV filter is an organic molecule selected from the following: occrylene, ethylhexyl salicylate, homosalate, butyl methoxydibenzoylmethane, diethylaminohydroxybenzoylhexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazine ketone, avobenzone, diethylhexylbutamidotriazine ketone, ethylhexyl methoxycinnamate, phenylbenzimidazole sulfonic acid, tri-biphenyl triazine, tri-biphenyl triazine (nano), oxybenzone, orsinolate. Octyltriazine, Octyl salicylate, Padimalate O, Bis-piperazine HAA299, Bis-piperazine HAA299 (nano), (2-ethoxyethyl(2Z)-2-cyano-2-[3-(3-methoxypropylamino)cyclohex-2-en-1-yl]acetate), Sulphone, Cresoltrazol trisiloxane, Methylene bis-benzotriazolyl tetramethylbutylphenol, Benzyl camphor sulfonic acid, 4-methylbenzylidene camphor, Polysiloxane-15, Sodium Sulphone, Aminobenzoic acid, PEG-25 PABA, Methylene bis-benzotriazolyl tetramethylbutylphenol, Methylene bis-benzotriazolyl tetramethylbutylphenol nano, Menthyl anthranilate, Isopentyl-4-methoxycinnamate, Terephthalimide dicamphor sulfonic acid, Dihydroxybenzophenone, Sinoxazone, Camphor benzalkonium sulfate and mixtures thereof.

8. The composition according to claims 1 to 6, wherein the UV filter is an inorganic compound, and the amount of the inorganic compound is from 1% to 25% by weight.

9. The composition of claim 8, wherein the UV filter is an inorganic compound selected from zinc oxide, anatase titanium dioxide, rutile, titanium dioxide and mixtures thereof, taking into account all size ranges of nanoscale, submicron scale and micron scale.

10. The composition according to any one of the preceding claims, wherein the UV filter is a mixture of an organic UV filter and an inorganic UV filter.

11. The composition according to any one of the preceding claims, wherein the zeolite provides at least 20% SPF enhancement to the sunscreen composition.

12. The composition according to any one of the preceding claims further comprises at least one of the following: cosmetically acceptable emollients, carriers, pigments, humectants, vitamins, antioxidants, emulsifiers, co-emulsifiers, hydrophilic or hydrophobic thickeners, waxes, lipids, film-forming agents, silicones, surfactants, activators, extracts, fragrances, preservatives, pH adjusters, suspending agents, and chelating agents.

13. The composition according to any one of the preceding claims, wherein it is formulated as a rod.

14. The composition according to any one of the preceding claims, wherein the composition is a homogeneous oil-in-water emulsion.

15. The composition according to any one of claims 1 to 14, used as a sunscreen agent, particularly in a method for protecting the stratum corneum from UV radiation, the method comprising contacting the stratum corneum with the sunscreen composition.

16. A zeolite selected from β-type, ZSM-5 type (MFI), Linde type (LTA), mordenite type (MOR), and octahedral zeolite type (FAU), said zeolite being functionalized with the silane portion selected from triethoxyoctylsilane, stearyltriethoxysilane, trimethylolhydroxysilane, or methoxypoly(ethyleneoxypropyltrimethoxysilane), said zeolite being used as an excipient in a sunscreen composition or for enhancing the SPF effect of a UV filter in a sunscreen composition.

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