Photonic barrier for topical use comprising bismuth oxide colloids

Abstract

To provide a composition intended to protect the skin from ultraviolet radiation and free from the drawbacks of conventional technology.SOLUTION: The present invention relates to a topical composition that creates a photonic barrier from ultraviolet radiation to visible radiation, comprising bismuth oxide colloids Bi2O3 in crystalline form doped with a metal.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to photonic barriers ranging from UV to visible light, and more specifically to doped bismuth oxide colloids, in particular α-Bi2O3 bismuth oxide, in a form that may optionally be grafted with a polymer, local compositions containing them, and their use.

[0002] The field of use of the present invention relates in particular to the fields of cosmetics and medical devices, and more specifically to the field of protection against electromagnetic radiation.

Background Art

[0003] It is well known that ultraviolet A (UV-A; 400 - 315 nm) accounts for 95% of the ultraviolet rays hitting the Earth's surface. These cause premature skin aging by generating free radicals and thus causing the phenomenon of oxidative stress.

[0004] Ultraviolet B (UV-B; 315 - 280 nm) has higher energy than UV-A. However, these are partially filtered by the atmosphere and account for 5% of the ultraviolet rays received on Earth. They are the cause of phototoxic erythema and also contribute to the acceleration of skin aging due to cellular oxidative stress caused by the generation of free radicals.

[0005] Ultraviolet C (UV-C; 280 - 100 nm) has even higher energy than UV-B. On the other hand, these are almost completely filtered by the ozone layer and are not particularly notable targets in the field of sun filters.

[0006] Visible ultraviolet (UV-V; 400 - 490 nm) has lower energy than other ultraviolet rays. However, they penetrate the skin the deepest, reach the reticular dermis, and are ultraviolet rays that can cause significant cell damage.

[0007] For the purposes of the present invention, the term "visible ultraviolet or UV-V" means visible radiation close to ultraviolet radiation, preferably radiation from 400 to 490 nm, advantageously from 400 to 450 nm, and even more advantageously from 400 to 420 nm.

[0008] All ultraviolet rays are involved in the carcinogenic mechanism.

[0009] Generally, sunscreen compositions contain at least one sunscreen agent, which can be organic or inorganic.

[0010] By way of example, and without limitation thereto, organic sunscreen agents can be compounds belonging to the following families: aminobenzoates, cinnamates, salicylates, benzophenones, phenylbenzotriazoles, etc.

[0011] Inorganic sunscreen agents include, in particular, titanium dioxide (TiO2) and zinc oxide (ZnO).

[0012] This type of protection makes it possible to limit the harmful effects of ultraviolet rays.

[0013] The various sunscreen agents described above do not cover the entire range of ultraviolet rays to which humans may be exposed. In fact, this is because filters are generally active against a limited range of wavelengths. For example, titanium dioxide and zinc oxide do not filter all of the UV-A, and the organic ethylhexyl triazone filter filters only UV-B.

[0014] Regarding more specific protection by filters against visible UV-V or ultraviolet rays, that is, protection against visible radiation close to ultraviolet rays, preferably from 400 to 490 nm, advantageously from 400 to 450 nm, and even more advantageously from 400 to 420 nm, so far, it has not been the subject of effective and specific development.

[0015] To solve this problem, sunscreen compositions generally combine several sunscreen agents and antioxidants that suppress the downstream effects of ultraviolet rays, mainly UV-A (400 - 315 nm) and UV-V (400 - 490 nm). It can be a mixture of organic and / or inorganic sunscreen agents.

[0016] However, combining multiple filters and many additives can cause problems of interaction between various elements and may affect the protective effect. On the other hand, organic filters can be easily absorbed from the skin. However, some organic filters are suspected of having an adverse effect on human health, especially being endocrine disruptors. Finally, various filters are prone to degradation, and here too the sunscreen effect is limited and may even harm the body.

Summary of the Invention

Problems to be Solved by the Invention

[0017] The problem proposed to be solved by the present invention is to develop a composition that is intended to protect the skin from ultraviolet rays and does not have the above-mentioned drawbacks.

Means for Solving the Problems

[0018] Bismuth oxide is generally used in the field of medical imaging as an X-ray opacifier or in the field of energy, for example, as an electrolyte in fuel cells.

[0019] The applicant has surprisingly noticed that bismuth oxide in a non-amorphous form, that is, crystalline bismuth oxide, can be used in cosmetic compositions, especially as an ultraviolet radiation filter.

[0020] According to a first aspect, the present invention relates to a topical composition comprising a metal-doped crystalline bismuth oxide colloid Bi2O3.

[0021] This composition creates a photonic (photohnic, light quantum) barrier in the range from ultraviolet to visible light, preferably from 200 to 490 nm, advantageously from 200 to 450 nm, and even more advantageously from 200 to 420 nm.

[0022] Thanks to the presence of bismuth oxide colloid Bi2O3 doped in crystalline form, this composition provides photonic protection by blocking a significantly wider part of electromagnetic radiation than commercial filters. Therefore, the present invention offers undeniable advantages over prior art compositions that require the use of several organic and / or inorganic filters to block the same range of wavelengths, especially UV-C and UV-V rays.

[0023] According to the present invention, the colloid refers to particles in crystalline form. They are also called quantum dots. In a liquid medium, such as an aqueous medium, the colloid forms a colloid suspension or a colloid dispersion.

[0024] According to a preferred embodiment, the colloid means a nanostructure or a nanocrystal.

[0025] Bismuth oxide colloid Bi2O3 can be synthesized according to conventional methods, for example, by the so-called "bottom-up" approach of precursor growth. In this synthesis route commonly used in the field of nanomaterials, a nucleation step and a growth step from isolated atoms are carried out. This makes it possible to control the size of the colloid.

[0026] Bismuth oxide colloid Bi2O3 can be synthesized from conventional precursors, such as bismuth oxalate, i.e., Bi2(C2O4)3 or Bi(C2O4)OH, or bismuth nitrate Bi(NO3)3.

[0027] According to a specific embodiment, the synthesis of Bi2O3 colloid can be carried out in a basic medium, for example, in the presence of sodium hydroxide.

[0028] According to another specific embodiment, the synthesis of Bi2O3 colloid can also be carried out in the presence of compounds such as nitric acid and / or polyvinylpyrrolidone and / or glycerin.

[0029] Advantageously, the synthesis of Bi2O3 colloid according to the present invention can be carried out in water.

[0030] The Bi2O3 crystals thus obtained can be processed by the following methods. - Precipitation; and / or - Washing, especially washing by filtration, and / or - Firing.

[0031] As already shown, the applicant has noticed that bismuth oxide colloid can act as an agent for blocking electromagnetic radiation, preferably ultraviolet radiation in the range of 200 nm to 420 nm, especially when it is applied to the skin.

[0032] Crystals can be classified into crystal systems according to their morphological symmetry and their physical properties.

[0033] Bismuth oxide Bi2O3 has various crystallographic (polymorphic) phases with various thermal, conductive, and optical properties, for example, - α phase; and - Tetragonal β phase; - γ phase with a centered cubic structure; - δ phase with a face-centered cubic structure It may have.

[0034] The α phase crystallizes in a monoclinic-type network with lattice parameters of a = 5.84 Å; b = 8.15 Å; c = 7.50 Å; β = 112.97°; and Z = 4 in the P2 1 / c space group. In this phase, ordered vacancies are seen at one-fourth of the free oxygen sites.

[0035] Depending on the synthesis conditions or temperature conditions, any of these phases can be promoted.

[0036] Unexpectedly, the doped bismuth oxide colloids, preferably the doped monoclinic bismuth oxide colloids, more preferably the doped monoclinic α-phase bismuth oxide colloids, exhibit a blocking effect over substantially the entire ultraviolet range, i.e., at wavelengths of 200 and 420 nm.

[0037] According to a particular embodiment, the composition according to the invention comprises bismuth oxide colloids Bi2O3 present only in a monoclinic crystal form.

[0038] According to a particular embodiment, the composition according to the invention comprises bismuth oxide colloids Bi2O3 present only in a monoclinic crystal form of the α-phase.

[0039] In other words, the composition according to the invention - of the β, γ, and δ phases; and / or - of the tetragonal, body-centered cubic, and face-centered cubic is lacking in bismuth oxide colloids Bi2O3.

[0040] According to an essential feature of the invention, the bismuth oxide colloids are doped with a doping agent, such as a metal.

[0041] For the purposes of the present invention, the terms "doped" and "doping" mean substituting bismuth atoms with metal atoms in the crystal lattice.

[0042] According to the invention, doping consists of carrying out the synthesis of the bismuth oxide colloids Bi2O3, in particular "bottom-up" and in the presence of a precursor of the doping agent or of the doping agent.

[0043] Within the meaning of the present invention, doping differs from conventional doping, which consists first in synthesizing the oxide colloids and then mixing them with a precursor of the doping agent.

[0044] According to the present invention, the shape of the crystal form does not change by doping. In other words, the X-ray powder diffraction pattern of the α-Bi2O3 colloid (α-phase and monoclinic lattice) exactly overlaps with the X-ray powder diffraction pattern of the α-Bi2O3 colloid (α-phase and monoclinic lattice) doped with a metal according to the present invention.

[0045] In contrast, in the prior art, when the α-Bi2O3 colloid is doped with an element, particularly a metal, the crystal form changes. Therefore, the colloid does not exist only in the form of the α-phase, but exists in the form of a mixture of the α-phase, γ-phase, and / or δ-phase.

[0046] According to a particular embodiment, the metal is selected from the group comprising alkali metals, alkaline earth metals, lanthanides, actinides, transition metals, poor metals, metalloids, and aggregates thereof. Advantageously, the metal is a transition metal.

[0047] For example, the doping of bismuth oxide colloid can be carried out using iron, manganese, magnesium, copper, chromium, nickel, or zinc, optionally excluding potassium or calcium.

[0048] Advantageously, the metal is iron.

[0049] Generally, this dopant occupies 0.01 to 5% by mass, more advantageously 0.01 to 0.15% by mass, based on the mass of Bi2O3 (before grafting with the biocompatible polymer).

[0050] When the bismuth oxide colloid is doped with a metal, preferably iron, the photocatalytic activity of the colloid is inhibited. This suppression of activity is due to the separation of the crystal mesh, which prevents the movement of electrons.

[0051] In addition to the electromagnetic radiation shielding function, the doped bismuth oxide colloid can also provide antioxidant, antibacterial, bactericidal, antibiofilm, antifungal, and antiviral properties to the cosmetic composition according to the present invention.

[0052] X-ray crystallography, also known as radiocrystallography or X-ray diffraction, enables the study of the structure of crystalline materials at the atomic scale. This technique is based on the physical phenomenon of X-ray diffraction. For example, a diffractometer with a copper radiation source can be used.

[0053] Therefore, the diffraction pattern forms the true signature of the crystalline form of the compound. This signature is unique to the crystalline form of the compound. It takes the form of a list of position peaks at the angle 2θ (2 theta).

[0054] According to a preferred embodiment of the present invention, the doped bismuth oxide colloid is preferably monoclinic, and even more preferably, the monoclinic system of α, the αBi2O3 phase, that is, the α-Bi2O3 phase.

[0055] In certain embodiments, the doped Bi2O3 colloid is grafted with a biocompatible polymer.

[0056] The bismuth oxide colloid used in the present invention does not correspond to those disclosed in the prior art particles, for example, those disclosed in JP 2010-090001 A and JP 2010-090002 A. These documents disclose undoped particles and / or ungrafted particles, and the crystal phases (α, β, γ, etc.) are not specified either.

[0057] For the purposes of the present invention, the term "biocompatible" means a compound that is cell-compatible with the skin, mucosa, and epidermis and exhibits less than 15%, preferably less than 10% cytotoxicity against a human epidermis reconstructed in vitro (SkinEthic RHE model). In other words, this compound remains almost neutral with respect to cell viability.

[0058] This cell compatibility can be evaluated by a cell viability test where the reagent is the tetrazolium salt: MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide].

[0059] The MTT assay is a colorimetric method for detecting mitochondrial activity and can evaluate the cytotoxicity of components. This is based on the reduction of the tetrazolium ring contained in the reagent to formazan by mitochondrial succinate dehydrogenase in viable cells. As a result, a purple precipitate is formed within the mitochondria.

[0060] In practice, after applying the test element to the epidermis for 42 minutes and then incubating for 42 hours after treatment, the cell viability is evaluated by measuring the activity of mitochondrial succinate dehydrogenase in viable cells. This enzyme converts MTT into blue formazan crystals. After dissolving these crystals, spectrophotometric readings of the optical density are taken at 550 nm. The measured absorbance value is proportional to the number of viable cells.

[0061] Biocompatible polymers can have hydrophilic or lipophilic properties. Advantageously, the biocompatible polymer is a hydrophilic polymer.

[0062] This biocompatible polymer can advantageously be hydrophilic and can be selected from the group consisting of polyvinylpyrrolidone (PVP) and its copolymers, such as triacontanyl-PVP, PVP-eicosene or PVP-vinyl acetate, polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, styrene-based, polyamide, acrylate, polyester, polybutene, polysaccharides, such as pullulan, arabinoxylan, cellulose, chitin, chitosan, xanthan gum, dextran, welan gum, gellan gum, gum arabic, hyaluronic acid, cellulose and its derivatives, starch, jute, proteins and their components, such as sericin and amino acids, fatty acids, phospholipids, phosphoglycerides, triglycerides, silane coupling agents and mixtures thereof.

[0063] Grafting prevents the penetration of Bi2O3 colloids into the skin by improving the bioadhesion between the colloid and the skin. In other words, by improving the adhesion of the colloid to the skin, the penetration of the colloid into the skin is restricted or prevented.

[0064] Through physical or mechanical interactions and chemical interactions, the biocompatible polymer functions as a bioadhesive on the skin. Thus, the composition according to the invention adheres to the skin and is not removed by simple washing with water or seawater.

[0065] The bioadhesion of the biocompatible polymer resulting from the formation of chemical bonds with the skin then leads to the following results: - Close contact between the biocompatible polymer and the skin. This close contact is supported by the wetting and / or swelling of the bioadhesive biocompatible polymer on the skin. - Filling of skin cracks and fine lines by the bioadhesive biocompatible polymer.

[0066] The biocompatible polymer also makes it possible to improve the dispersibility of Bi2O3 colloids in an aqueous medium, and thus to obtain a uniform distribution when the composition according to the invention is applied to the skin. Thus, the composition containing the colloid according to the invention is advantageously a composition in which the colloid is in a suspended state.

[0067] Grafting with a biocompatible polymer can improve the stability of Bi2O3 colloids over time and / or improve the acidic pH, particularly the skin pH, to 5.2 - 7. Without grafting, Bi2O3 colloids, especially α - Bi2O3, become unstable over time and / or degrade more rapidly at a pH below 7.

[0068] The concept of grafting or functionalizing colloids is part of the general knowledge of those skilled in the art. Grafting or functionalizing corresponds to the formation of covalent bonds, for example, the formation of covalent bonds between the biocompatible polymer and the surface of the colloid. These are not core / shell type colloids.

[0069] The biocompatible polymer can impart lipophilic or hydrophilic properties to the colloid.

[0070] Generally, the composition may advantageously contain 1 to 60% by weight, more advantageously 20 to 50% by weight, based on the mass of the composition, of grafted and doped Bi2O3 colloid. This is the weight percentage of the doped and advantageously grafted Bi2O3 colloid.

[0071] Advantageously, the doped Bi2O3 colloid of the composition may contain 60 to 100%, advantageously 80 to 100%, preferably 100% of the doped bismuth oxide colloid in the α-crystalline form, preferably the doped monoclinic α-crystalline form of the bismuth oxide colloid. These doped colloids in the α-crystalline form are advantageously grafted with a biocompatible polymer. In other words, according to this embodiment, 60 to 100%, preferably 80 to 100%, more preferably 100% of the doped Bi2O3 colloid of the composition is in the α-crystalline form.

[0072] The Bi2O3 colloid advantageously has a spherical shape.

[0073] Whether doped and grafted or not, the Bi2O3 colloid in the α-crystalline phase, preferably the monoclinic α-crystalline phase, advantageously has a size on the order of 0.5 to 1000 nm, more advantageously 0.5 to 100 nm, even more advantageously 30 nm.

[0074] The size is measured by XRD (X-ray diffraction), a technique for measuring the size of crystals in the solid state.

[0075] The term "size" refers to the maximum dimension of the colloid, for example the diameter in the case of a spherical colloid. This is the average size of the grafted or ungrafted colloid. In fact, the size of the grafted colloid according to the present invention is also included within the range of the values described above.

[0076] According to certain embodiments, the composition may also include lipophilic and / or hydrophilic inorganic sunscreen agents. This filter can be selected, in particular, from the group consisting of titanium oxide (TiO2), zinc (ZnO), iron (Fe2O3), zirconium (ZrO2), silicon (SiO2), manganese (e.g., MnO), aluminum (Al2O3), cerium (Ce2O3), and mixtures thereof.

[0077] Advantageously, the inorganic sunscreen agent is colloidal or particulate.

[0078] According to another certain embodiment, the composition may also include lipophilic and / or hydrophilic organic sunscreen agents. This filter can be selected, in particular, from the group consisting of camphor benzalkonium methosulfate, homosalate, butyl methoxydibenzoylmethane, phenylbenzimidazole-sulfonic acid, terephthalylidene dicamphor sulfonic acid, butyl methoxydibenzoylmethane, benzylidene camphor sulfonic acid, octocrylene, polyamide methoxybenzylidene camphor, ethylhexyl methoxycinnamate, PEG-25 PABA, isomamil p-methoxycinnamate, ethylhexyl triazone, droxmetrizole trisiloxane, diethylhexyl butamido triazone, 4-methylbenzylidene camphor, 3-benzylidene camphor, ethylhexyl salicylate, ethylhexyl dimethyl PABA or octyl dimethyl PABA, benzophenone-5 / benzophenone-4, methylene bis-benzotriazolyl tetramethylbutylphenol, disodium phenyl dibenzimidazole tetrasulfonate, bis-ethylhexyloxyphenol methoxyphenyl triazine, polysilicone-15, diethylamino hydroxybenzoyl hexyl benzoate, and mixtures thereof.

[0079] According to certain embodiments, the topical composition is intended for therapeutic use.

[0080] According to another certain embodiment, the topical composition is not intended for therapeutic use.

[0081] Advantageously, the composition according to the invention is a sunscreen composition.

[0082] The composition according to the invention is preferably in the form of an aqueous suspension of colloids doped with a metal and advantageously grafted, preferably in the form of an aqueous suspension of colloids doped with a metal and advantageously grafted, Oil-based in the form of a suspension, or alternatively in the form of an oil-in-water or water-in-water emulsion containing colloids preferably doped with a metal and advantageously grafted.

[0083] The biocompatible polymer can have hydrophilic or lipophilic properties.

[0084] When the composition contains an oil-based dispersant, the biocompatible polymer grafted onto the bismuth oxide colloid is advantageously lipophilic.

[0085] When the composition contains a water-based dispersant, the biocompatible polymer grafted onto the bismuth oxide colloid is advantageously hydrophilic.

[0086] The composition according to the invention advantageously contains 2 to 20% by weight, more advantageously 4 to 10% by weight of biocompatible polymer, based on the mass of the composition. These percentages preferably include biocompatible polymers optionally grafted onto Bi2O3 colloids doped with a metal.

[0087] According to a particular embodiment, the composition according to the invention may further comprise at least one additive selected from the group consisting of a dispersant, a humectant, a stabilizer, and a pH regulator.

[0088] Advantageously, the dispersant is water and / or oil.

[0089] Preferably, the oil is selected from the group consisting of hydrocarbon oils derived from plants (such as sunflower, corn, soybean, grape seed, sesame, hazelnut, castor oil, etc.), hydrocarbon oils (such as paraffin oil, etc.) derived from minerals or synthesized (linear or branched), silicone oils (such as polymethylsiloxane, cyclopolysiloxane, etc.), fluorinated oils, and mixtures thereof.

[0090] According to another embodiment, the oil can be a hydrocarbon oil derived from animals.

[0091] The dispersant is preferably water.

[0092] In practice, the composition according to the present invention preferably contains 20 to 80% by mass of water and / or oil, more preferably 40 to 60% by mass of water and / or oil, based on the mass of the composition.

[0093] Preferably, the humectant is selected from the group consisting of glycerol, urea, lactic acid, and mixtures thereof.

[0094] The composition according to the present invention preferably contains between 5% and 25% by mass, preferably between 7% and 15% by mass, of the humectant, based on the mass of the composition.

[0095] The humectant helps prevent the composition from drying out too rapidly after application to the skin. It also helps to give the skin a moisturized feeling. Additionally, it can contribute to controlling the viscosity of the composition according to the present invention for the purpose of optimizing the spread of the composition on the skin.

[0096] Preferably, the stabilizer is selected from the group consisting of sorbitan monolaurate, guar gum, xanthan gum, and mixtures thereof.

[0097] The composition according to the present invention preferably contains 0.5 to 5% by mass, more preferably 1 to 3% by mass, of the stabilizer, based on the mass of the composition.

[0098] The stabilizer makes it possible to adjust the viscosity of the composition.

[0099] Advantageously, the pH regulator is selected from the group consisting of citric acid, acetic acid, adipic acid, ascorbic acid, boric acid, fumaric acid, glycolic acid, lactic acid, malic acid, uric acid, and mixtures thereof.

[0100] The composition according to the invention advantageously contains from 0.1 to 1% by weight, more advantageously from 0.2 to 0.5% by weight, of pH regulator, based on the weight of the composition.

[0101] The pH regulator makes it possible to maintain the pH of the composition at a physiological value. By adjusting the pH when the composition is applied to the skin, i.e., when adapted to an acidic medium, the stability of the composition is improved.

[0102] A person skilled in the art will know how to adapt the amount of pH regulator so that the composition advantageously has a pH of between 5.2 and 7.

[0103] According to a particular embodiment, the composition according to the invention advantageously does not contain preservatives, which is not the case for most conventional sunscreen compositions.

[0104] As already mentioned, this cosmetic composition is a topical composition. This composition has many advantages, including in particular the following: - It is a simple formulation containing a small number of components, advantageously in an aqueous medium, - An enhanced effect in protecting against a wide range of ultraviolet rays (UV-C, UV-B, UV-A, and UV-V) (such a composition is likened to a solar paint), - A very high sun protection factor, - Little or no penetration into the stratum corneum (the outermost cell layer of the skin), protecting sensitive and atopic skin, - Good adhesion to the skin, providing long-lasting sun protection.

[0105] According to a preferred embodiment, the composition according to the invention contains, based on the weight of the composition: - 1 to 60% by mass of a doped bismuth oxide colloid, preferably monoclinic α-type (α-Bi2O3), preferably a doped bismuth oxide colloid grafted with a biocompatible polymer; - 2 to 20% by mass of a structured biocompatible polymer, preferably polyvinylpyrrolidone (PVP); - 5 to 25% by mass of a humectant, preferably glycerol; - 0.5 to 5% by mass of a stabilizer, preferably sorbitan monolaurate; - 0.1 to 1% by mass of a pH adjuster, preferably citric acid; and - 20 to 80% by mass of water and / or oil.

[0106] According to a preferred embodiment, the composition according to the invention comprises, based on the mass of the composition: - 1 to 60% by mass of a doped bismuth oxide colloid, preferably present only in monoclinic α-type (α-Bi2O3), preferably a doped bismuth oxide colloid grafted with a biocompatible polymer; - 2 to 20% by mass of a structured biocompatible polymer, preferably polyvinylpyrrolidone (PVP); - 5 to 25% by mass of a humectant, preferably glycerol; - 0.5 to 5% by mass of a stabilizer, preferably sorbitan monolaurate; - 0.1 to 1% by mass of a pH adjuster, preferably citric acid; and - 20 to 80% by mass of water and / or oil.

[0107] Advantageously, the composition according to the invention can be stored in a medium lacking carbon dioxide and advantageously lacking oxygen. These storage conditions make it possible to extend the shelf life of the composition according to the invention.

[0108] The present invention relates to the use of doped bismuth oxide colloids (α-Bi2O3), preferably grafted with a biocompatible polymer, as ultraviolet filters in the wavelength spectrum of UV-A, UV-B, UV-C and UV-V, preferably from 200 to 420 nm. This use is particularly suitable when the colloid is contained in a topical cosmetic composition.

Brief Description of the Drawings

[0109]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0110] The present invention and the advantages resulting therefrom will become clearly apparent from the above-described figures and the following examples presented without limiting to explain the present invention.

Examples

[0111] 1 / [Synthesis of Doped Bismuth Oxide Colloid] Mix a bismuth oxide precursor, such as bismuth nitrate pentahydrate, etc., and an iron precursor, such as iron chloride, etc., with water, nitric acid, and sodium hydroxide, and then seal them in an autoclave.

[0112] Next, precipitate the reaction mixture, then wash it by filtration, and then perform a calcination process at a temperature of 100 - 500 °C.

[0113] When the reaction mixture reaches the set temperature, maintain the temperature until the doped bismuth oxide crystallizes.

[0114] Spherical bismuth oxide nanocrystals with a diameter of 7 nm are collected.

[0115] The X-ray powder diffraction pattern comparing the peaks of Bi2O3 colloid (α-Bi2O3) that exists only in the α-phase crystal form within the monoclinic lattice according to the present invention and the peaks of commercially available α-Bi2O3 colloid is shown in FIG. 5.

[0116] The results show that the commercially available α-Bi2O3 colloid exhibits the presence of additional and / or different peaks compared to the colloid according to the present invention. The commercially available α-Bi2O3 colloid is a mixture of α-phase and gamma-phase bismuth oxide. In fact, the peak at about 2θ of 30° corresponds to the gamma-phase rather than the α-phase, and the minor peaks around the main peak at about 2θ of 27.5° are not expected in the gamma-phase but are seen in the α-phase.

[0117] In contrast, the colloid according to the present invention is pure and does not show additional peaks that may be attributed to crystal phases of bismuth oxide other than the α-phase. In other words, the colloid according to the present invention corresponds only to the crystal form of the α-phase in the monoclinic array.

[0118] 2 / [α-Bi2O3, TiO2 and ZnO colloids] The absorption spectra of monoclinic α-Bi2O3 colloid, TiO2 particles, and ZnO particles were compared.

[0119] For this purpose, the following compounds were used in water. (a) Anatase-type TiO2 colloid (40 nm, aggregates of about 250 nm measured by DLS). This TiO2 is grafted with 2 mass% of PVP. (b) ZnO colloid (15 nm) grafted with 2 mass% of PVP, (c) Iron-doped α-Bi2O3 colloid (colloid of α-phase and monoclinic array; 30 nm measured by XRD, 40 nm measured by DLS) grafted with 2 mass% of PVP.

[0120] Mass% indicates the mass percentage of PVP with respect to the mass of TiO2, ZnO, or α-Bi2O3 doped with iron.

[0121] Grafting of the colloid is carried out by a conventional method, for example, in a solution of water and ethanol containing the colloid and the polymer (PVP) to be grafted.

[0122] The wavelength generated by the diffractometer used for measuring the size by XRD corresponds to the Cu-Kα line equal to 1.54 Å. Other parameters used are: acceleration voltage: 40 kV; current: 40 mA; Bragg-Brentano type geometry.

[0123] The conditions for size measurement by DLS are: wavelength equal to 633 nm; detector at 90°; 25 °C. The analysis sample is diluted in cocosilicon oil in a 1 mm cell (0.5 g / L).

[0124] 2-a) [Mass absorption coefficient] The average mass absorption coefficient (ε) based on wavelength of these compounds was obtained from measurements using a conventional spectrophotometer. The average mass absorption coefficient corresponds to the average of the measurements carried out for solutions of 10 mass% (100 g / L), 0.75 mass% (7.5 g / L), and 0.05 mass% (0.5 g / L) in cells of thickness 10 μm, 100 μm, and 0.1 cm. This mass absorption coefficient is based on the Lambert-Beer equation: ε = A / lC (Where A is the measured absorbance, l (cm) is the optical path through the sample, and C (g / L) is the mass concentration of the sample.) is obtained from

[0125] The results are shown in Figure 2

[0126] TiO2 particles exhibit a higher average mass absorption coefficient in the UV-B region (280 - 315 nm). However, the doped α-Bi2O3 colloids (α-phase and monoclinic array) show a significantly higher UV-A (315 - 400 nm) absorption ability than TiO2. The average mass absorption coefficient of ZnO remains low regardless of these wavelengths.

[0127] 2-b) [Protection from Ultraviolet Rays] The sun protection factor (SPF), UV-A protection factor (SP-UVA), and critical wavelength of the solutions (a), (b), and (c) described above are calculated using the following equations: [Equation] (Where E λ represents the erythema action spectrum (a value from 0 to 1) at wavelength λ. This is a measure of the potential of ultraviolet rays at wavelength λ to cause erythema on the skin.) S λ represents the spectral irradiance at wavelength λ.) T λ represents the transmittance of the sample at wavelength λ.) d λ represents the integration variable.) Calculations were made for a cell with a thickness of 10 μm.)

[0128] The values of E λ and S λ are known.)

[0129] The critical wavelength corresponds to the wavelength at which the ratio R is 0.9 or greater. In other words, it is the integral of the spectral curve: [Equation] is the wavelength equal to 90% of the integral from 290 to 400 nm.

[0130] The critical wavelengths of the compounds TiO2, ZnO, and α-Bi2O3 are equal to 368 nm, 362 nm, and 382 nm, respectively.

[0131] Only the α-Bi2O3 compound alone can achieve a critical wavelength above 370 nm.

[0132] Figure 3 shows the sun protection factors (SPFs) of particles grafted with TiO2, ZnO, and iron-doped α-Bi2O3 (α-phase and monoclinic array) based on their mass percentages (0.1–30 wt%) in a 10 μm tank.

[0133] These curves are used to determine the amount of sunscreen needed to achieve a given Sun Protection Factor (SPF). Table 1 shows the weight percent needed to achieve an SPF of 20, 30, 50, or 100 from the data in Figure 3.

[0134] [Table 1]

[0135] Tables 2 and 3 show the UVA protection factors (SP-UVA) for SPFs of 50 and 100 and the SPF:SP-UVA ratios.

[0136] [Table 2]

[0137] [Table 3]

[0138] From Figure 3, the effectiveness of the three investigated inorganic filters is TiO2 > Bi2O3 > ZnO at concentrations of 0.1 to 10% by mass, and Bi2O3 > TiO2 > ZnO when the concentration exceeds 10% by mass.

[0139] On the other hand, α-Bi2O3 colloids doped with iron (α-phase and monoclinic arrays) exhibit a broader absorption range than conventional inorganic filters (Figure 1). Therefore, they make it possible to eliminate the need to rely on mixtures of organic and / or inorganic filters.

[0140] 3 / [Photocatalytic activity] The photocatalytic activity of the inorganic UV filters is evaluated by monitoring the decomposition of methylene blue in the presence of various filters or controls and UV radiation.

[0141] The inorganic filters tested are oxides. More specifically, they are ZnO and α-Bi2O3 doped with iron according to the present invention.

[0142] Specifically, 10 μL of a 50 g / L oxide suspension in water is added to 4990 μL of a 1E -5 mol.L -1 aqueous solution of methylene blue. The control is performed in the same manner by adding 10 μL of water instead of the oxide suspension in 4990 μL of a 1E -5 mol.L -1 aqueous solution of methylene blue. The solution is placed in the dark for 30 minutes to achieve the adsorption equilibrium of the dye on the surface of the oxide under study.

[0143] Next, the absorbance of the solution is measured in the region of 540 nm to 710 nm. This corresponds to the absorption of methylene blue. These measured values constitute the values at time t = 0 minutes. Subsequently, the solution is stirred under UV illumination.

[0144] Absorbance measurements are taken at 15, 30, 45, 60, 90, and 120 minutes.

[0145] The relative amount of methylene blue compared with the measured value at t = 0 minutes can be measured by the area under the curve in the range of 540 nm to 710 nm.

[0146] The results are shown in Figure 4.

[0147] The results indicate that zinc oxide has significant photocatalytic activity with 90% decomposition of methylene blue within 30 minutes.

[0148] The control shows about 10% decomposition due to the photodegradation of the dye under UV, which is not due to photocatalysis.

[0149] In the case of the doped α-Bi2O3 colloid (α-phase and monoclinic array) according to the present invention, the decomposition is almost zero, indicating that the oxide has no photocatalytic activity. Only 2% of methylene blue was decomposed, so the photodegradation of the dye also seems to be limited compared to the control. This phenomenon is due to the absorption of some of the UV radiation and the reduction of ROS by the iron-doped α-Bi2O3 colloid according to the present invention.

[0150] 4 / [Cosmetic composition according to the present invention] The composition according to the present invention was prepared and compared with a commercially available solar composition (Table 4).

[0151]

Table 4

[0152] Generally, Table 4 shows that the composition containing the inorganic UV filter is most effective in blocking UV-V (visible UV: 400 - 450 nm).

[0153] The composition according to the present invention has the highest effect over the entire UV range (UV-C, UV-B, UV-A, and UV-V).

[0154] The skin penetration test showed that the composition containing the organic filter penetrates deeper into the skin than the composition containing a mixture of the organic filter and the inorganic filter or the composition containing only the inorganic filter.

[0155] The best results are obtained for the composition according to the invention. It is a much lower penetration into the skin than the other compositions. As already shown, this effect is most likely due to the improvement of the colloidal bioadhesion by grafting with the biocompatible polymer.

Claims

1. Crystalline form of bismuth oxide colloid Bi ２ O ３ A topical composition that contains and generates a photonic barrier in the range from ultraviolet light to visible light A topical composition, wherein the bismuth oxide colloid is doped with a metal.

2. The topical composition according to claim 1, wherein the bismuth oxide colloid is monoclinic.

3. The topical composition according to claim 1 or 2, characterized in that the bismuth oxide colloid is in the monoclinic α-phase (α-Bi ２ O ３ ).

4. The topical composition according to any one of claims 1 to 3, characterized in that the bismuth oxide colloid exists only in the monoclinic α-phase (α-Bi ２ O ３ ).

5. The monoclinic system has the following mesh parameters: a = 5.84 Å; b = 8.15 Å; c = 7.50 Å; β = 112.97°; P2 １／ｃ The topical composition according to any one of claims 1 to 4, characterized in that it corresponds to Z = 4 in the space group.

6. The topical composition according to any one of claims 1 to 5, wherein the metal is iron.

7. The topical composition according to any one of claims 1 to 6, wherein the bismuth oxide colloid is grafted with a biocompatible polymer.

8. The bismuth oxide colloid is grafted with a biocompatible polymer selected from the group consisting of polyvinylpyrrolidone (PVP) and its copolymers (such as triacontanyl-PVP, PVP-eicosene, or PVP-vinyl acetate, etc.), polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, styrene-based resins, polyamides, acrylates, polyesters, polybutene, polysaccharides (such as pullulan, arabinoxylan, cellulose, chitin, chitosan, xanthan gum, dextran, welan gum, gellan gum, gum arabic, hyaluronic acid, cellulose and its derivatives, starch, diutan, etc.), proteins and their components (such as sericin and amino acids), fatty acids, phospholipids, phosphoglycerides, triglycerides, silane coupling agents, and mixtures thereof. The topical composition according to any one of claims 1 to 7.

9. The topical composition according to any one of claims 1 to 8, comprising 1 to 60% by mass, preferably 20 to 50% by mass, of the doped bismuth oxide colloid, preferably the doped bismuth oxide colloid grafted with a biocompatible polymer, based on the mass of the topical composition.

10. Doped bismuth oxide colloid Bi ２ O ３ The topical composition according to any one of claims 1 to 9, characterized in that it comprises 60 to 100% of a doped α-crystalline phase bismuth oxide colloid, preferably a doped α-crystalline phase bismuth oxide colloid grafted with a biocompatible polymer.

11. The topical composition according to any one of claims 1 to 10, wherein the doped bismuth oxide colloid, preferably the doped bismuth oxide colloid grafted with a biocompatible polymer, has a size in the range of 0.5 nm to 1000 nm, preferably 0.5 nm to 100 nm.

12. The following: - Titanium oxide (TiO ２ ), zinc (ZnO), iron (Fe ２ O ３ ), zirconium (ZrO ２ ), silicon (SiO ２ ), manganese (e.g., MnO, etc.), aluminum (Al ２ O ３ ), cerium (Ce ２ O ３ ), and at least one lipophilic and / or hydrophilic inorganic sunscreen agent selected from the group consisting of mixtures thereof; and / or, At least one lipophilic and / or hydrophilic organic sunscreen agent selected from the group consisting of camphor benzalkonium metosulfate, homosalate, butyl methoxydibenzoylmethane, phenylbenzimidazole-sulfonic acid, terephthalylidene dicamphor sulfonic acid, butyl methoxydibenzoylmethane, benzylidene camphor sulfonic acid, octocrylene, polyacrylamide methyl benzylidene camphor, ethylhexyl methoxycinnamate, PEG-25 PABA, isomamil p-methoxycinnamate, ethylhexyl triazone, droxmetrizole trisiloxane, diethylhexyl butamidotriazone, 4-methylbenzylidene camphor, 3-benzylidene camphor, ethylhexyl salicylate, ethylhexyl dimethyl PABA or octyl dimethyl PABA, benzophenone-4 / benzophenone-5, methylene bis-benzotriazolyl tetramethylbutylphenol, disodium phenyl dibenzimidazole tetrasulfonate, bis-ethylhexyloxyphenol methoxyphenyl triazine, polysilicone-15, diethylamino hydroxybenzoyl hexyl benzoate, and mixtures thereof The topical composition according to any one of claims 1 to 11, further comprising the same.

13. The topical composition according to any one of claims 1 to 12, further comprising at least one additive selected from the group consisting of a dispersant, a humectant, a stabilizer, and a pH adjuster.

14. The topical composition according to any one of claims 1 to 13, which is a sunscreen composition.

15. With respect to the total mass of the topical composition, the following: - 1 to 60% by mass of a doped monoclinic α-phase bismuth oxide colloid (α-Bi ２ O ３ ), preferably a doped monoclinic α-phase bismuth oxide colloid (α-Bi ２ O ３ ) grafted with a biocompatible polymer; - 2 to 20% of a biocompatible polymer, preferably polyvinylpyrrolidone; - 5 to 25% by mass of a humectant, preferably glycerol; - 0.5 to 5% by mass of a stabilizer, preferably sorbitan monolaurate; - 0.1 to 1% by mass of a pH adjuster, preferably citric acid; and - 20 to 80% by mass of water and / or oil The topical composition according to any one of claims 1 to 14, comprising the same.

16. Doped bismuth oxide (Bi ２ O ３ ), preferably doped bismuth oxide (Bi ２ O ３ ) colloids grafted with a biocompatible polymer, for use as an ultraviolet filter, preferably an ultraviolet filter in the wavelength spectrum of 200 to 420 nm.

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