Photonic barrier for topical use, containing bismuth oxide colloid.

Abstract

The problem that this invention aims to solve is the development of a composition intended to protect the skin from ultraviolet rays and that does not have the drawbacks of the prior art. [Solution] The present invention relates to a topical composition that generates a photonic barrier from ultraviolet to visible light, comprising metal-doped crystalline bismuth oxide colloid Bi2O3.

Description

[Technical Field]

[0001] The present invention relates to topical compositions comprising a photonic barrier extending from UV to visible light, more specifically, doped bismuth oxide colloid, particularly bismuth oxide α-Bi2O3, which may optionally be grafted with a polymer, and to the use thereof.

[0002] The field of application of this invention is particularly related to the fields of cosmetics and medical devices, and more specifically to the field of protection against electromagnetic radiation. [Background technology]

[0003] It is well known that ultraviolet A (UV-A; 400-315nm) accounts for 95% of the ultraviolet radiation that hits the Earth's surface. These generate free radicals and therefore cause premature skin aging by triggering oxidative stress.

[0004] Ultraviolet B (UV-B; 315-280 nm) has higher energy than UV-A. However, it is partially filtered by the atmosphere and accounts for 5% of the ultraviolet radiation received on Earth. It is a cause of actinic erythema and also contributes to accelerated skin aging due to oxidative stress on cells caused by the generation of free radicals.

[0005] Ultraviolet C (UV-C; 280-100 nm) has even higher energy than UV-B. However, these are almost completely filtered by the ozone layer and are not of particular interest in the field of sunscreens (sun filters).

[0006] Visible ultraviolet (UV-V; 400-490nm) has lower energy than other types of ultraviolet radiation. However, it is the type of UV radiation that penetrates the deepest into the skin, reaching the reticular dermis and potentially causing significant cell damage.

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

[0008] All ultraviolet radiation is involved in the mechanism of carcinogenesis.

[0009] Generally, a sunscreen composition contains at least one sunscreen agent, which may be organic or inorganic.

[0010] For example, and not limited to, organic sunscreens may be compounds belonging to the following families: aminobenzoates, cinnamates, salicylates, benzophenones, phenylbenzotriazoles, etc.

[0011] Inorganic sunscreens, in particular, contain titanium dioxide (TiO2) and zinc oxide (ZnO).

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

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

[0014] More specific protection against visible UV-V or ultraviolet radiation by filters, i.e., protection against visible radiation close to ultraviolet radiation, preferably 400-490 nm, more favorably 400-450 nm, and even more favorably 400-420 nm, has not been effectively and specifically developed to date.

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

[0016] However, combining multiple filters with numerous additives can lead to interaction problems between various elements, potentially affecting the protective effect. On the other hand, organic filters can be easily absorbed through the skin. However, some organic filters are suspected of having adverse effects on human health, particularly as endocrine disruptors. Finally, various filters are prone to degradation, which again limits sunscreen effectiveness and can even be harmful to the body. [Overview of the project] [Problems that the invention aims to solve]

[0017] The problem that this invention aims to solve is to develop a composition that is intended to protect the skin from ultraviolet rays and does not have the aforementioned drawbacks. [Means for solving the problem]

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

[0019] The applicant, quite unexpectedly, discovered that bismuth oxide in a non-amorphous form, i.e., bismuth oxide in a crystalline form, can be used in cosmetic compositions, particularly as an ultraviolet radiation filter.

[0020] According to a first aspect, the present invention relates to a topical composition comprising a metal-doped crystalline form of 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 crystalline form-doped bismuth oxide colloid Bi2O3, this composition provides photonic protection by blocking a significantly wider part of electromagnetic radiation than commercial filters. Therefore, the present invention provides undeniable advantages over prior art compositions that require the use of several organic and / or inorganic filters to block the same range of wavelengths, particularly 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 obtained in this way can be processed by the following method. - Precipitation; and / or - Washing, especially washing by filtration, and / or - Firing.

[0031] As already indicated, the applicant has found that bismuth oxide colloid can act as an agent for blocking electromagnetic radiation, preferably 200 nm to 420 nm, and more preferably ultraviolet radiation, especially when applied to the skin.

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

[0033] Bismuth oxide (Bi2O3) exists in various crystallographic (polymorphic) phases with diverse thermal, conductive, and optical properties, for example, - α-phase; and - The β phase of the tetragonal crystal system; - Gamma phase of a central cubic structure; - Face-centered cubic δ phase It may have.

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

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

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

[0037] According to certain embodiments, the composition according to the present invention contains bismuth oxide colloid Bi2O3, which exists only in a monoclinic crystalline form.

[0038] According to certain embodiments, the composition according to the present invention contains bismuth oxide colloid Bi2O3, which exists only in the monoclinic crystalline form of the α phase.

[0039] In other words, the composition according to the present invention is - of the β, γ, and δ phases; and / or - Tetragonal, centered cubic, and face centered cubic It lacks bismuth oxide colloid (Bi2O3).

[0040] According to the essential features of the present invention, bismuth oxide colloid is doped with a doping agent, such as a metal.

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

[0042] According to the present invention, doping consists of synthesizing bismuth oxide colloid Bi2O3, particularly by a "bottom-up" method, and in the presence of a doping agent precursor or doping agent.

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

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

[0045] In contrast, in conventional techniques, doping α-Bi2O3 colloid with elements, particularly metals, alters its crystalline form. Therefore, the colloid does not exist solely in the form of the α phase, but rather as a mixture of the α, gamma, and / or δ phases.

[0046] According to certain embodiments, the metal is selected from the group including 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, bismuth oxide colloid doping can be carried out using iron, manganese, magnesium, copper, chromium, nickel, or zinc, with the optional exclusion of potassium or calcium.

[0048] Conveniently, the metal is iron.

[0049] Generally, this dopant accounts for 0.01–5% by mass, more favorably 0.01–0.15%, of the mass of Bi2O3 (before grafting with biocompatible polymer).

[0050] When 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 electron transfer.

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

[0052] X-ray crystallography, also known as radiation crystallography or X-ray diffraction, makes it possible to study 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 source can be used.

[0053] Therefore, the diffraction pattern forms a true signature of the compound's crystalline form. This signal is specific to the compound's crystalline form. It takes the form of a list of positional peaks at an angle of 2θ (2 theta).

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

[0055] In certain embodiments, doped Bi2O3 colloids are grafted with biocompatible polymers.

[0056] The bismuth oxide colloid used in this invention is a prior art particle, for example, one disclosed in Japanese Patent Publication No. 2010-090001 and Japanese Patent Publication No. 2010-090002. equivalent This is not the case. These documents disclose undoped and / or ungrafted particles, and the crystalline phase (α, β, γ, etc.) is not specified.

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

[0058] This cytocompatibility can be evaluated by a cell viability test using the tetrazolium salt:MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide] as the reagent.

[0059] The MTT test is a colorimetric method for detecting mitochondrial activity and can evaluate the cytotoxicity of components. It is based on the reduction of the tetrazolium ring in the reagent to formazan by mitochondrial succinate dehydrogenase in active living cells. This results in the formation of a purple precipitate within the mitochondria.

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

[0061] Biocompatible polymers may have hydrophilic or lipophilic properties. Advantageously, biocompatible polymers are hydrophilic polymers.

[0062] This biocompatible polymer may be advantageously hydrophilic and may be selected from the group comprising polyvinylpyrrolidone (PVP) and its copolymers, e.g., triacontanyl-PVP, PVP-eicosene or PVP-vinyl acetate, polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, styrene-based compounds, polyamides, acrylates, polyesters, polybutenes, polysaccharides, e.g., pullulan, arabinoxylan, cellulose, chitin, chitosan, xanthan gum, dextran, gellan gum, gum arabic, hyaluronic acid, cellulose and its derivatives, starch, rutin, proteins and their components, e.g., sericin and amino acids, fatty acids, phospholipids, phosphoglycerides, triglycerides, silane coupling agents and mixtures thereof.

[0063] Grafting prevents the Bi2O3 colloid from penetrating the skin by improving bioadhesion between the colloid and the skin. In other words, by improving the colloid's adhesion to the skin, its penetration into the skin is limited or prevented.

[0064] Through physical or mechanical interactions and chemical interactions, biocompatible polymers function as bioadhesives on the skin. Therefore, the compositions according to the present invention adhere to the skin and are not removed by simple washing with water or seawater.

[0065] The bioadhesion of biocompatible polymers, 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 wetting and / or swelling of the bioadhesive biocompatible polymer on the skin. - Filling skin cracks and fine lines with bioadhesive, biocompatible polymers.

[0066] Biocompatible polymers also enable improved dispersibility of Bi2O3 colloids in aqueous media, thus allowing for a uniform distribution when the composition according to the present invention is applied to the skin. Therefore, the composition containing the colloid according to the present invention is advantageously a composition in which the colloid is suspended.

[0067] Grafting with biocompatible polymers can improve the stability of Bi2O3 colloid over time and / or improve the acidic pH, particularly the pH of skin, to 5.2-7. Without grafting, Bi2O3 colloid, especially α-Bi2O3, becomes unstable over time and / or degrades more rapidly at pH levels below 7.

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

[0069] Biocompatible polymers can impart lipophilic or hydrophilic properties to colloids.

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

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

[0072] Bi2O3 colloids are advantageously spherical in shape.

[0073] Whether doped or grafted, Bi2O3 colloids, preferably in an α-crystalline phase, more preferably monoclinic α-crystalline phase, have sizes on the order of 0.5–1000 nm, more preferably 0.5–100 nm, and even more preferably 30 nm.

[0074] The size is measured by XRD (X-ray diffraction), a technique used to measure the size of crystals in their 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 grafted or ungrafted colloids. In fact, the size of the grafted colloid according to the present invention also falls within the range of the values ​​described above.

[0076] According to certain embodiments, the composition may also include lipophilic and / or hydrophilic inorganic sunscreens. These filters can be selected from the group including titanium dioxide (TiO2), zinc (ZnO), iron (Fe2O3), zirconium (ZrO2), silicon (SiO2), manganese (e.g., MnO), aluminum (Al2O3), cerium (Ce2O3), and mixtures thereof.

[0077] Advantageously, inorganic sunscreens are colloidal or particulate.

[0078] According to another specific embodiment, the composition may also include lipophilic and / or hydrophilic organic sunscreens. This filter is particularly INCI designated as 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 The following can be selected from the group comprising PABA, isomamyl p-methoxycinnamate, ethylhexyl triazone, drometrizole trisiloxane, diethylhexyl butamide triazone, 4-methylbenzylidene camphor, 3-benzylidene camphor, ethylhexyl salicylate, ethylhexyldimethyl PABA or octyldimethyl PABA, benzophenone-5 / benzophenone-4, methylenebis-benzotriazolyltetramethylbutylphenol, disodium phenyldibenzimidazole tetrasulfonate, bis-ethylhexyloxyphenol methoxyphenyl triazine, polysilicone-15, diethylamino hydroxybenzoylhexyl benzoate, and mixtures thereof.

[0079] According to certain embodiments, topical compositions are intended for therapeutic use.

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

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

[0082] The compositions according to the present invention may be in the form of an aqueous suspension of a metal-doped, and preferably grafted, colloid, preferably in the form of a suspension of a metal-doped, and preferably grafted, colloid, or in the form of a water-in-oil or water-in-water emulsion containing a metal-doped, and preferably grafted, colloid.

[0083] Biocompatible polymers may have hydrophilic or lipophilic properties.

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

[0085] When the composition contains an aqueous dispersant, the biocompatible polymer grafted onto bismuth oxide colloid is advantageously hydrophilic.

[0086] The compositions according to the present invention preferably contain 2 to 20% by mass, and more preferably 4 to 10% by mass, of a biocompatible polymer based on the mass of the composition. These percentages include, preferably, a biocompatible polymer optionally grafted onto a metal-doped Bi2O3 colloid.

[0087] According to certain embodiments, the composition according to the present invention may further comprise at least one additive selected from the group consisting of dispersants, humectants, stabilizers, and pH adjusters.

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

[0089] Preferably, the oil is selected from the group comprising plant-derived hydrocarbon oils (such as sunflower, corn, soybean, grape seed, sesame, hazelnut, and castor oil), mineral-derived or synthetic (linear or branched) hydrocarbons (such as paraffin oil), silicone oils (such as polymethylsiloxane and cyclopolydimethylsiloxane), fluorinated oils, and mixtures thereof.

[0090] According to another embodiment, the oil may be an animal-derived hydrocarbon oil.

[0091] The dispersant is preferably water.

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

[0093] Advantageously, the humectant is selected from the group comprising glycerol, urea, lactic acid, and mixtures thereof.

[0094] The composition according to the present invention preferably contains a humectant in an amount between 5 and 25% by mass, and preferably between 7 and 15% by mass, relative to the mass of the composition.

[0095] Moisturizers help prevent the composition from drying out too quickly after application to the skin. They also help to moisturize the skin. Furthermore, they can contribute to controlling the viscosity of the composition according to the present invention, with the aim of optimizing the spread of the composition on the skin.

[0096] Advantageously, the stabilizer is selected from the group comprising 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 of a stabilizer, and more preferably 1 to 3% of a stabilizer, relative to the mass of the composition.

[0098] Stabilizers allow for adjustment of the viscosity of the composition.

[0099] Advantageously, the pH adjusting agent is selected from the group comprising 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 present invention preferably contains 0.1 to 1% by mass of a pH adjusting agent, and more preferably 0.2 to 0.5% of a pH adjusting agent, based on the mass of the composition.

[0101] pH adjusters enable the maintenance of a composition's pH at physiological levels. They improve the composition's stability by adjusting its pH when applied to the skin, i.e., when exposed to an acidic medium.

[0102] Those skilled in the art will know how to adjust the amount of pH adjusting agent so that the composition has a pH of 5.2 to 7, which is advantageous.

[0103] According to certain embodiments, the compositions of the present invention are advantageously preservative-free, which is not true for most conventional sunscreen compositions.

[0104] As already mentioned, this cosmetic composition is a topical composition. This composition has many advantages, among others: - A simple formulation containing, advantageously, a small number of ingredients in an aqueous medium. - Enhanced effectiveness in protection against a wide range of ultraviolet rays (UV-C, UV-B, UV-A, and UV-V) (such compositions are likened to solar paint), - Very high sun protection coefficient, - It penetrates the stratum corneum (the outermost layer of skin cells) with little to no penetration, protecting sensitive and atopic skin. - To ensure good adhesion to the skin and prolong the life of sunscreen.

[0105] According to a preferred embodiment, the composition according to the present invention comprises the following, with respect to the mass of the composition: - 1-60% by mass of doped bismuth oxide colloid, preferably monoclinic α-type (α-Bi2O3), and preferably grafted with a biocompatible polymer; - 2 to 20% by mass of a structured biocompatible polymer, preferably polyvinylpyrrolidone (PVP); - 5-25% 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 adjusting agent, preferably citric acid; and - 20-80% by mass of water and / or oil.

[0106] According to a preferred embodiment, the composition according to the present invention comprises the following, with respect to the mass of the composition: - Doped bismuth oxide colloids, preferably existing only in monoclinic α-type (α-Bi2O3), and preferably grafted with biocompatible polymers, in concentrations of 1-60% by mass; - 2 to 20% by mass of a structured biocompatible polymer, preferably polyvinylpyrrolidone (PVP); - 5-25% 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 adjusting agent, preferably citric acid; and - 20-80% by mass of water and / or oil.

[0107] Advantageously, the compositions according to the present invention can be stored in a medium that is devoid of carbon dioxide and, advantageously, devoid of oxygen. These storage conditions allow for an extension of the shelf life of the compositions according to the present invention.

[0108] The present invention also relates to the use of doped bismuth oxide colloid (α-Bi2O3), preferably doped bismuth oxide colloid (α-Bi2O3) grafted with a biocompatible polymer, as an ultraviolet filter for UV-A, UV-B, UV-C, and UV-V wavelengths, preferably in the 200-420 nm range. This use is particularly suitable when the colloid is contained in a topical cosmetic composition. [Brief explanation of the drawing]

[0109] [Figure 1] Figure 1 shows the absorption spectra of organic and inorganic sunscreens, and a sunscreen according to a preferred embodiment of the present invention (doped α-Bi2O3). [Figure 2] Figure 2 shows the wavelength-based reflectance of doped colloidal solutions of TiO2, ZnO, and α-Bi2O3. [Figure 3] Figure 3 shows the sun protection factor (SPF) based on mass percentage for compositions containing doped TiO2, ZnO, and α-Bi2O3 grafted particles. [Figure 4] Figure 4 shows the analysis of the photocatalytic activity of an inorganic sunscreen agent using a preferred embodiment of the present invention (doped α-Bi2O3) and a control. [Figure 5] Figure 5 shows an X-ray powder diffraction pattern comparing the peak of the α-Bi2O3 colloid (monoclinic α-crystalline phase) according to the present invention with the peak of a commercially available α-Bi2O3 colloid. [Modes for carrying out the invention]

[0110] The present invention and the advantages arising therefrom will become clearly apparent from the above-mentioned figures and the following embodiments, which are presented without limitation for the purpose of illustrating the invention. [Examples]

[0111] 1 / [Synthesis of doped bismuth oxide colloids] A bismuth oxide precursor, such as bismuth nitrate pentahydrate, and an iron precursor, such as iron chloride, are mixed with water, nitric acid, and sodium hydroxide, and then sealed in an autoclave.

[0112] Next, the reaction mixture is allowed to settle, then washed by filtration, and finally calcined at a temperature of 100-500°C.

[0113] Once 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] Figure 5 shows X-ray powder diffraction patterns comparing the peak of Bi2O3 colloid (α-Bi2O3) that exists only in the α-phase crystal form within the monoclinic lattice according to the present invention with the peak of commercially available α-Bi2O3 colloid.

[0116] The results show that, compared to the colloid according to the present invention, commercially available α-Bi2O3 colloids exhibit the presence of additional and / or different peaks. Commercially available α-Bi2O3 colloids are mixtures of bismuth oxide in the α and gamma phases. In fact, the 2θ peak at approximately 30° corresponds to the gamma phase, not the α phase, and minor peaks around the main 2θ peak at approximately 27.5° are not expected in the gamma phase but are present in the α phase.

[0117] In contrast, the colloid according to the present invention is pure and does not exhibit additional peaks that could be attributed to crystalline phases of bismuth oxide other than the α-phase. In other words, the colloid according to the present invention corresponds only to the crystalline form of the α-phase in a 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 approximately 250 nm as measured by DLS). This TiO2 is grafted with 2 mass% PVP. (b) ZnO colloid (15 nm) grafted with 2 mass% PVP, (c) Iron-doped α-Bi2O3 colloid grafted with 2 mass% PVP (colloid of α-phase and monoclinic array; measured at 30 nm by XRD and 40 nm by DLS).

[0120] Mass% is 、T iO2, ZnO, or Iron doped This shows the mass percentage of PVP relative to the mass of α-Bi2O3.

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

[0122] The wavelength produced by the diffractometer used to measure the size by XRD corresponds to the Cu-Kα line, which is 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 were: wavelength equal to 633 nm; detector at 90°; and 25°C. The sample for analysis was diluted in cocoa silicone oil in a 1 mm tank (0.5 g / L).

[0124] 2-a) [Mass extinction coefficient] The wavelength-based average mass extinction coefficient (ε) of these compounds was obtained from measurements using a conventional spectrophotometer. The average mass extinction coefficient corresponds to the average of measurements performed on 10% by mass (100 g / L), 0.75% by mass (7.5 g / L), and 0.05% by mass (0.5 g / L) solutions in tanks with thicknesses of 10 μm, 100 μm, and 0.1 cm. This mass extinction coefficient is given by the Lambert-Beer formula: ε = A / 1C (In the formula, 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.) It is obtained from.

[0125] The results are shown in Figure 2.

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

[0127] 2-b) [Protection from ultraviolet rays] The sun protection factor (SPF) and UV-A protection factor of the solutions (a), (b), and (c) described above. S The P-UVA (P-UVA) and critical wavelength are given by the following formula:

number

[0128] Value E λ and S λ This is known.

[0129] The critical wavelength corresponds to the wavelength where the ratio R is 0.9 or greater. In other words, it is the integral of the spectral curve:

number

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

[0131] Only α-Bi2O3 compounds can achieve a critical wavelength exceeding 370 nm on their own.

[0132] Figure 3 shows the sun protection factor (SPF) of particles grafted with TiO2, ZnO, and iron-doped α-Bi2O3 (α-phase and monoclinic arrays), based on their mass percentage (0.1–30 mass%) 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 mass percentage required to achieve an SPF of 20, 30, 50, or 100, based on the data in Figure 3.

[0134] [Table 1]

[0135] Tables 2 and 3 show, When SPF is 50 and 100 UVA protection factor (SP-UVA ) and S This shows the PF:SP-UVA ratio.

[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 similarly 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 area under the curve from 540nm to 710nm allows for the measurement of the relative amount of methylene blue compared to the measured value at t=0 min.

[0146] The results are shown in Figure 4.

[0147] The results indicate that zinc oxide possesses significant photocatalytic activity, resulting in the decomposition of 90% of methylene blue within 30 minutes.

[0148] The control shows approximately 10% degradation of the pigment due to photodegradation under UV light, not due to photocatalytic action.

[0149] In the case of the doped α-Bi2O3 colloid (α-phase and monoclinic array) according to the present invention, decomposition was almost zero, indicating the absence of photocatalytic activity of the oxide. Only 2% of methylene blue was decomposed, suggesting that the photodecomposition of the dye was also limited compared to the control. This phenomenon is due to the partial absorption of 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] A composition according to the present invention was prepared and compared with a commercially available solar composition (Table 4).

[0151] [Table 4]

[0152] In general, Table 4 shows that compositions containing inorganic UV filters are most effective at blocking UV-V (visible UV: 400-450 nm).

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

[0154] Skin penetration tests showed that compositions containing organic filters penetrated the skin more deeply than compositions containing a mixture of organic and inorganic filters or compositions containing only inorganic filters.

[0155] The best results are obtained with the composition according to the present invention, which exhibits significantly less skin penetration than other compositions. As already shown, this effect is almost certainly due to improved bioadhesion of the colloid by grafting with a biocompatible polymer.

Claims

1. Bismuth oxide colloid in crystalline form ２ O ３ A topical composition that generates a photonic barrier in the range from ultraviolet to visible light, comprising: A topical composition characterized in that the bismuth oxide colloid is doped with a metal.

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

3. Bismuth oxide colloid is the α-phase of the monoclinic crystal system (α-Bi ２ O ３ The topical composition according to claim 1 or 2, characterized in that it is the same as the above.

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

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 A topical composition according to any one of claims 1 to 4, characterized in that Z = 4 in the space group.

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

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

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

9. A topical composition according to any one of claims 1 to 8, characterized by containing 1 to 60% by mass, preferably 20 to 50% by mass, of doped bismuth oxide colloid, or preferably 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 contains 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. A topical composition according to any one of claims 1 to 10, characterized in that the doped bismuth oxide colloid, preferably 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. below: - Titanium oxide (TiO ２ ), zinc (ZnO), iron (Fe ２ O ３ ), zirconium (ZrO ２ ), silicon (SiO ２ ), manganese (e.g., MnO), aluminum (Al ２ O ３ ), cerium (Ce ２ O ３ At least one lipophilic and / or hydrophilic inorganic sunscreen selected from the group comprising ), and mixtures thereof; and / or - INCI designated substances: Camphor benzalkonium methosulfate, homosalate, butyl methoxydibenzoylmethane, phenyl benzimidazole sulfonic acid, terephthalylidene dicamphor sulfonic acid, butyl methoxydibenzoylmethane, benzylidene camphor sulfonic acid, octocrylene, polyacrylamide methylbenzylidene camphor, ethylhexyl methoxycinnamate, PEG-25 At least one lipophilic and / or hydrophilic organic sunscreen selected from the group comprising PABA, isomamyl p-methoxycinnamate, ethylhexyl triazone, drometrizole trisiloxane, diethylhexyl butamide triazone, 4-methylbenzylidene camphor, 3-benzylidene camphor, ethylhexyl salicylate, ethylhexyldimethyl PABA or octyldimethyl PABA, benzophenone-4 / benzophenone-5, methylenebis-benzotriazolyltetramethylbutylphenol, phenyldibenzimidazole tetrasulfonate disodium, bis-ethylhexyloxyphenol methoxyphenyl triazine, polysilicone-15, diethylamino hydroxybenzoylhexyl benzoate, and mixtures thereof. A topical composition according to any one of claims 1 to 11, further comprising the above.

13. A topical composition according to any one of claims 1 to 12, further comprising at least one additive selected from the group consisting of dispersants, humectants, stabilizers, and pH adjusters.

14. A topical composition according to any one of claims 1 to 13, characterized in that it is a sunscreen composition.

15. With respect to the total mass of the above composition, the following applies: - 1 to 60 mass% of doped monoclinic α-phase bismuth oxide colloid (α-Bi ２ O ３ ), advantageously, doped monoclinic α-phase bismuth oxide colloid (α-Bi) grafted with biocompatible polymers. ２ O ３ ); - 2-20% 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 adjusting agent, preferably citric acid; and - 20 to 80% by mass of water and / or oil A topical composition according to any one of claims 1 to 14, characterized by containing the following:

16. Doped bismuth oxide (Bi ２ O ３ ) Colloid, preferably doped bismuth oxide (Bi) grafted with biocompatible polymers ２ O ３ ) Colloidal ultraviolet filters, advantageously used as ultraviolet filters for wavelength spectra of 200-420 nm.

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