UV-PROTECTIVE COMPOSITIONS AND THEIR USE
20190125638 ยท 2019-05-02
Inventors
Cpc classification
A61Q17/04
HUMAN NECESSITIES
A61K8/0245
HUMAN NECESSITIES
A61K2800/412
HUMAN NECESSITIES
C01G49/0054
CHEMISTRY; METALLURGY
C01P2004/62
CHEMISTRY; METALLURGY
A61K8/8135
HUMAN NECESSITIES
A61K8/8147
HUMAN NECESSITIES
C01P2006/60
CHEMISTRY; METALLURGY
A61K8/0241
HUMAN NECESSITIES
C01P2002/72
CHEMISTRY; METALLURGY
C01P2004/51
CHEMISTRY; METALLURGY
International classification
A61Q17/04
HUMAN NECESSITIES
A61K8/81
HUMAN NECESSITIES
Abstract
Disclosed are UV protective compositions comprising BLT crystals having the formula Bi.sub.(4-x)La.sub.(x)Ti.sub.(3-y)Fe.sub.(y)O.sub.12, wherein x is between 0.1 and 1.5; and wherein y is between 0 and 2. There are also disclosed compositions comprising nanoparticles of such BLT crystals, the nanoparticles being optionally dispersed in a polymer matrix. Methods of preparation and uses of such compositions are also provided.
Claims
1. A UV-protective composition comprising one or more Lanthanum-Modified Bismuth Titanate (BLT) crystals each independently having the chemical formula Bi.sub.(4-x)La.sub.(x)Ti.sub.(3-y)Fe.sub.(y)O.sub.12 as an ultraviolet-absorbing agent, wherein x is between 0.1 and 1.5; and wherein y is between 0 and 2.
2. The composition according to claim 1, wherein said one or more BLT crystals have a perovskite structure.
3. The composition according to any one of claim 1 or claim 2, wherein x is between 0.5 and 1.0, suitably wherein x is between 0.7 and 0.8.
4. The composition according to any one of claim 1 to claim 3, wherein y is between 0.01 and 1.8.
5. The composition according to any one of claim 1 to claim 4, wherein x and y respectively are selected from (0.0625 and 2.9375), (0.125 and 2.875), (0.25 and 2.75), (1 and 2) and (1.5 and 1.5).
6. The composition according to any one of claim 1 to claim 5, wherein the one or more BLT crystals are in the form of nanoparticles consisting of one or more said crystals, at least 50%, generally at least 90%, of the total number of said nanoparticles having at least one dimension of up to about 200 nm, or up to about 150 nm, or up to about 100 nm, said nanoparticles optionally consisting of crystals having the same chemical formula.
7. The composition according to any one of claim 1 to claim 5, wherein the one or more BLT crystals are in the form of nanoparticles consisting of one or more said crystals, at least 50%, generally at least 90%, of the total volume of said nanoparticles having at least one dimension of up to about 200 nm, or up to about 150 nm, or up to about 100 nm, said nanoparticles optionally consisting of crystals having the same chemical formula.
8. The composition according to either one of claim 6 and claim 7, wherein said nanoparticles of said one or more BLT crystals are dispersed with a dispersant in a polymer matrix further comprising a thermoplastic polymer swelled with an oil.
9. The composition according to claim 8, said polymer matrix is in the form of polymer matrix flakes wherein each flake of said polymer matrix flakes has a flake length (Lf), a flake width (Wf), and a flake thickness (Tf), said polymer matrix flakes having a dimensionless flake aspect ratio (Rf) defined by: Rf=(Lf.Math.Wf)/(Tf).sup.2, wherein, with respect to a representative group of at least ten polymer matrix flakes, an average Rf is at least 5; and wherein the nanoparticles within said representative group have an average particle size (D50) of at most 100 nm.
10. The composition according to either one of claim 8 and claim 9, wherein the flake aspect ratio (Rf) of the polymer matrix flakes is within a range of from about 5 to about 2000, generally from about 10 to about 1000, suitably from about 12 to about 500, typically from about 12 to about 200, and more typically from about 15 to about 100.
11. The composition according to any one of claim 8 to claim 10, wherein the dispersant adapted to disperse the nanoparticles of BLT crystals within said polymer matrix has a hydrophilic-lipophilic balance (HLB) value of at most 9, generally at most 6, suitably at most 4, and more suitably at most 3.
12. The composition according to any one of claim 8 to claim 11, wherein said nanoparticles of said one or more BLT crystals are present within said polymer matrix at a concentration of from about 0.01 to about 8% v/v of said thermoplastic polymer; suitably from about 0.4 to about 5% v/v of the thermoplastic polymer, and more suitably from about 0.6 to about 3% (v/v) of the thermoplastic polymer.
13. The composition according to any one of claim 8 to claim 12, wherein said oil is present at a concentration of from about 10 to about 50% (w/w) of said thermoplastic polymer, generally from about 5 to about 50% (v/v) the thermoplastic polymer, suitably from about 30% (w/w) more suitably from about 20% (v/v) of the thermoplastic polymer.
14. The composition according to any one of claim 8 to claim 13, wherein the thermoplastic polymer in the polymer matrix comprises at least one ethylene-acrylic (EAA) polymer, ethylene-methacrylic (EMMA) polymer, ethyl vinyl acetate (EVA) polymer, or combinations thereof.
15. The composition according to any one of claim 1 to claim 14 containing less than 5 wt. %, less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, less than 1 wt. %, less than 0.5 wt. %, less than 0.1 wt. % or less than 0.05 wt. % organic ultraviolet-absorbing agent(s), suitably being generally devoid of organic ultraviolet-absorbing agent(s).
16. The composition according to any one of claim 1 to claim 15, containing less than 5 wt. %, less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, less than 1 wt. %, less than 0.5 wt. %, less than 0.1 wt. % or less than 0.05 wt. % additional inorganic ultraviolet-absorbing agent(s), suitably being generally devoid of an additional inorganic ultraviolet-absorbing agent.
17. The composition according to any one of claim 1 to claim 16, wherein the one or more BLT crystals constitute the only ultraviolet-absorbing agents in the composition.
18. The composition according to any one of claim 1 to claim 17, formulated as one of the following: (a) a skin-care composition for application to human or non-human animal skin; (b) a hair-care composition for application to human or non-human animal hair; or (c) a coating composition for application to an inanimate surface.
19. The composition according to any one of claim 1 to claim 18, for use in protecting a subject or an inanimate object against a harmful effect of ultraviolet radiation.
20. The composition according to any one of claim 1 to claim 18, for use in protecting the skin or the hair of a subject against a harmful effect of ultraviolet radiation.
21. The composition for use according to any one of claim 19 and claim 20, wherein protecting against ultraviolet radiation comprises protecting against ultraviolet A radiation and ultraviolet B radiation.
22. The composition according to any one of claim 1 to claim 21, wherein the composition has a critical wavelength of at least 370 nm.
23. The composition according to claim 22 having a critical wavelength of 371 nm, 372 nm, 373 nm, 374 nm, 375 nm, 376 nm, 377 nm, 378 nm, 379 nm, 380 nm, 381 nm, 382 nm, 383 nm, 384 nm, 385 nm, 386 nm, 387 nm, 388 nm, 389 nm, 390 nm, 391 nm, 392 nm, or greater than 392 nm.
24. The composition according to any one of claim 1 to claim 23, wherein the area under the curve (AUC) formed by the UV-absorption of the one or more BLT crystals as a function of wavelength in the range of 280 nm to 400 nm (AUC.sub.280-400) is at least 75%, at least 85% or at least 95% of the AUC formed by the same crystals at the same concentration in the range of 280 nm to 700 nm (AUC.sub.280-700).
25. A method of protecting a surface from UV radiation, comprising applying to said surface an efficacious amount of a composition according to any one of claim 1 to claim 18.
26. The method of claim 24, wherein the surface is one of: (a) a human skin; (b) a non-human animal skin; (c) human hair; (d) non-human animal hair; and (e) an inanimate surface.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0113] Some embodiments of the invention are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some embodiments of the disclosure may be practiced.
[0114] The figures are for the purpose of illustrative discussion and no attempt is made to show structural details of an embodiment in more detail than is necessary for a fundamental understanding of the disclosure. For the sake of clarity, some objects depicted in the figures are not to scale.
[0115] In the Figures:
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DETAILED DESCRIPTION
[0129] The present disclosure, in at least some embodiments, provides compositions for protection against ultraviolet radiation, uses of such compositions and methods of making such compositions.
[0130] The UV protective compositions disclosed herein comprise Fe-doped or undoped BLT crystals having the formula Bi.sub.(4-x)La.sub.(x)Ti.sub.(3-y)Fe.sub.(y)O.sub.12, wherein x is between 0.1 and 1.5; and wherein y is between 0 and 2, which when present as large particles (e.g., dimensions in each of the X-, Y- and Z-directions being greater than 200 nanometers (nm), resulting for instance in a hydrodynamic diameter of more than 200 nm as measured by DLS) may effectively absorb radiation having wavelengths of greater than about 400 nm. Accordingly, compositions comprising such large particles of composite BLT, whether or not further substituted by iron atoms, may provide protection against ultraviolet radiation having wavelengths up to at least 400 nm.
[0131] However, in the case in which the UV-protective composition is a sunscreen composition which comprises BLT, but which also contains particles that absorb light at wavelengths in the range of 400-800 nm, the sunscreen will be visible on the end-user because of the absorption in the visible range (>400 nm).
[0132] It has surprisingly been found by the present Inventors that, although reduction of particle size of known inorganic UV-absorbing agents to dimensions of, for example below 1 micrometer (m), typically below 100 nm (for instance, reduction to nanometric dimensions) is known to significantly reduce the maximum wavelength of light, including UV light, which is effectively absorbed by the particles, UV protective compositions according to the present teachings comprising particles of doped or undoped BLT crystals milled to nanoparticle size still provide substantial absorption of UV radiation of wavelength from 280 nm (or even shorter wavelength) up to about 400 nm, thus providing broad-spectrum protection against both UVA and UVB radiation, even in the absence of additional ultraviolet-absorbing agents.
[0133] Thus, in some embodiments, UV protective compositions disclosed herein, such as sunscreen compositions, comprise doped or undoped BLT crystals in the form of particles comprising one or more said crystals, wherein at least 90% of the particles are nanoparticles. In some embodiments, at least 95%, or at least 97.5% or at least 99% of the particles, in terms of number or volume of particles, are nanoparticles. In some embodiments, at least one dimension of the BLT crystal nanoparticles is expressed in terms of the hydrodynamic diameter as measured by DLS techniques.
[0134] In some embodiments, the cumulative particle size distribution in a sample is assessed in terms of the number of particles in the sample (denoted D.sub.N). In some embodiments, the cumulative particle size distribution in a sample is assessed in terms of the volume of particles in the sample (denoted D.sub.V).
[0135] In some embodiments, the maximum diameter of the nanoparticles is assessed for population distribution measured in terms of number of particles and percentage thereof. In some embodiments, the maximum diameter of the nanoparticles is assessed for population distribution measured in terms of sample volume of particles and percentage thereof.
[0136] In some embodiments, the doped or undoped BLT crystal nanoparticles are substantially invisible to the human eye, in particular when applied to the skin or hair of a subject, or if desired when applied to an inanimate surface, due to their small size.
[0137] In some embodiments, the doped or undoped BLT crystal nanoparticles are blended into a coloured composition and need not be substantially transparent and/or invisible, for instance when used in a make-up product, such as a foundation, which is slightly tinted when applied to the skin of a subject, or when used in a stain or paint applicable to inanimate surfaces.
[0138] According to some embodiments of the disclosure, there is provided a UV protective composition comprising undoped BLT crystals.
[0139] According to some embodiments of the disclosure, there is provided a UV protective composition comprising Fe-doped BLT crystals, the level of doping by iron atoms being such that the Fe:Ti ratio can be between 1:50 and 1:2, in particular between 1:20 and 1:2.
[0140] According to a further aspect of some embodiments of the disclosure, there is provided a UV protective composition comprising doped or undoped BLT crystals for use in protecting the skin of a subject, such as a human subject, against ultraviolet radiation, in some embodiments providing broad-spectrum protection against both ultraviolet A and ultraviolet B radiation.
[0141] According to a further aspect of some embodiments of the disclosure, there is provided a UV protective composition comprising doped or undoped BLT crystals for use in protecting the hair of a subject, such as a human subject, against ultraviolet radiation, in some embodiments against both ultraviolet A and ultraviolet B radiation.
[0142] According to a further aspect of some embodiments of the disclosure, there is provided a method of protecting the skin of a subject against ultraviolet radiation, the method comprising applying to the skin of the subject an efficacious amount of a UV protective composition comprising doped or undoped BLT crystals. In some such embodiments, the UV-protective composition can be in the form of a skin-care product suitable for skin application and/or at least temporary retention thereupon.
[0143] According to a further aspect of some embodiments of the disclosure, there is provided a method of protecting the hair of a subject against ultraviolet radiation, the method comprising applying to the hair of the subject an efficacious amount of a UV protective composition comprising doped or undoped BLT crystals. In some such embodiments, the UV-protective composition can be in the form of a hair-care product suitable for hair application and/or at least temporary retention thereupon.
[0144] According to a further aspect of some embodiments of the disclosure, there is provided a method of protecting the surface of an inanimate object against ultraviolet radiation, the method comprising applying to the surface of the object an efficacious amount of a UV protective composition comprising doped or undoped BLT crystals. In some such embodiments, the UV-protective composition can be in the form of a coating product suitable for application to inanimate surfaces and/or at least temporary retention thereupon.
[0145] According to a further aspect of some embodiments of the disclosure, there is provided the use of doped or undoped BLT crystals in the manufacture of a composition for protection of the skin of a subject against ultraviolet radiation.
[0146] According to a further aspect of some embodiments of the disclosure, there is provided the use of doped or undoped BLT crystals in the manufacture of a composition for protection of the hair of a subject against ultraviolet radiation.
[0147] According to a further aspect of some embodiments of the disclosure, there is provided the use of doped or undoped BLT crystals in the manufacture of a composition for protection of surfaces of an object against ultraviolet radiation.
[0148] According to a further aspect of some embodiments of the disclosure, there is provided a method of manufacturing a UV protective composition, comprising combining doped or undoped BLT crystals, as an ultraviolet-absorbing agent, with other ingredients in proportions and in a manner suitable to make a UV-protective composition as described herein.
[0149] In some embodiments of the composition, use or method disclosed herein, the BLT crystals are present in the composition at a concentration of from about 0.001 wt. % to about 40 wt. %, from about 0.01 wt. % to about 30 wt. %, from about 0.1 wt. % to about 20 wt. % or from about 0.1 wt. % to about 15 wt. % of the final composition.
[0150] In some embodiments, the BLT crystals constitute at least 0.01 wt. %, at least 0.1 wt. %, at least 0.5 wt. %, at least 1 wt. %, at least 2 wt. %, at least 3 wt. %, at least 4 wt. %, at least 5 wt. %, at least 10 wt. %, at least 15 wt. %, at least 20 wt. %, at least 25 wt. %, at least 30 wt. %, or at least 35 wt. % of the composition. In some embodiments, the BLT crystals constitute at most 40 wt. %, at most 35 wt. %, at most 30 wt. %, at most 25 wt. %, at most 20 wt. %, at most 15 wt. %, at most 10 wt. %, at most 5 wt. %, at most 4 wt. %, at most 3 wt. %, at most 2 wt. %, at most 1 wt. %, at most 0.5 wt. %, or at most 0.1 wt. % of the composition.
[0151] In some embodiments of the composition, use or method disclosed herein, the doped or undoped BLT crystals are present in the composition as nanoparticles having at least one dimension of up to about 200 nm. In some embodiments, the nanoparticles have at least one dimension in the range of from about 10 nm to about 200 nm, from about 20 nm to about 150 nm, from about 20 to about 100 nm, from about 10 nm to about 80 nm, from about 10 to about 70 nm, from about 20 to about 70 nm, or from about 20 to about 60 nm, In some particular embodiments, the nanoparticles have at least one dimension of about 30 nm.
[0152] In some embodiments, the afore-mentioned dimensions or ranges of dimensions apply to at least 95%, or at least 97.5% or at least 99% of the population of the nanoparticles.
[0153] In some embodiments, the aforesaid smallest dimension of doped or undoped BLT crystals is estimated based on the hydrodynamic diameter of the particles as measured by DLS techniques. In some embodiments, the population distribution of the particles is expressed in terms of the cumulative particle size distribution, according to the number of particles in a sample. In some embodiments, the population distribution of the particles is expressed in terms of the cumulative particle size distribution of a sample volume of particles.
[0154] In some embodiments of the composition, use or method disclosed herein, the composition is generally devoid and/or generally free of an organic ultraviolet-absorbing agent.
[0155] In some embodiments of the composition, use or method disclosed herein, the composition is generally free of an organic ultraviolet-absorbing agent, that is to say the composition contains less than 5 wt. % organic UV-absorbing agents. In some embodiments the composition contains less than 4 wt. %, less than 3 wt. %, less than 2 wt. % or less than 1 wt. % organic UV-absorbing agents. In some embodiments the composition is largely free of organic ultraviolet-absorbing agents, i.e. the composition contains less than 0.5 wt. % organic UV-absorbing agents. In some embodiments the composition is mostly free of organic UV-absorbing agents, i.e. the composition contains less than 0.1 wt. % organic UV-absorbing agents. In some embodiments, the composition is principally free of organic ultraviolet-absorbing agents, i.e. the composition contains less than 0.05 wt. % organic UV-absorbing agents. In some embodiments, the composition is fundamentally free of organic UV-absorbing agents, i.e. the composition contains less than 0.01 wt. % organic UV absorbing agents. In some embodiments of the composition, use or method disclosed herein, the composition is generally devoid of organic ultraviolet-absorbing agents, considerably devoid of organic ultraviolet-absorbing agents, significantly devoid of organic ultraviolet-absorbing agents, substantially devoid of organic ultraviolet-absorbing agents, essentially devoid of organic ultraviolet-absorbing agents, substantively devoid of organic ultraviolet-absorbing agents or devoid of organic ultraviolet-absorbing agents.
[0156] In some embodiments of the composition, use or method disclosed herein, the composition is generally devoid and/or generally free of an additional inorganic ultraviolet-absorbing agent.
[0157] In some embodiments of the composition, use or method disclosed herein, the composition if generally free of an additional inorganic ultraviolet-absorbing agent, that is to say the composition contains less than 5 wt. % additional inorganic UV-absorbing agents. In some embodiments, the composition contains less than 4 wt. %, less than 3 wt. %, less than 2 wt. % or less than 1 wt. % additional inorganic UV-absorbing agents. In some embodiments, the composition is largely free of additional inorganic ultraviolet-absorbing agents, i.e. the composition contains less than 0.5 wt. % additional inorganic UV-absorbing agents. In some embodiments, the composition is mostly free of additional inorganic UV-absorbing agents, i.e. the composition contains less than 0.1 wt. % additional UV-absorbing agents. In some embodiments, the composition is principally free of additional inorganic ultraviolet-absorbing agents, i.e. the composition contains less than 0.05 wt. % additional UV-absorbing agents. In some embodiments, the composition is fundamentally free of additional inorganic UV-absorbing agents, i.e. the composition contains less than 0.01 wt. % additional UV absorbing agents.
[0158] In some embodiments of the composition, use or method disclosed herein, the composition is generally devoid of additional ultraviolet-absorbing agents, considerably devoid of additional ultraviolet-absorbing agents, significantly devoid of additional ultraviolet-absorbing agents, substantially devoid of additional ultraviolet-absorbing agents, essentially additional of organic ultraviolet-absorbing agents, substantively devoid of additional ultraviolet-absorbing agents or devoid of additional ultraviolet-absorbing agents.
[0159] In some embodiments of the composition, use or method disclosed herein, the doped or undoped BLT crystals are the sole ultraviolet-absorbing agent.
[0160] In some embodiments of the composition, use or method disclosed herein, the composition further comprises silver metal particles.
[0161] In some embodiments, the silver metal particles are present in the composition as nanoparticles. In some embodiments, the silver nanoparticles have at least one dimension of up to about 50 nm. In some embodiments, the silver nanoparticles have at least one dimension of up to about 40 nm. In some embodiments, the silver nanoparticles have at least one dimension of up to about 30 nm. In some embodiments, the silver nanoparticles have at least one dimension in the range of from about 10 nm to up to about 50 nm.
[0162] In some embodiments, the afore-mentioned dimensions or ranges of dimensions apply to at least 90%, or at least 95%, or at least 97.5% or at least 99% of the population of the silver nanoparticles.
[0163] In some embodiments, the aforesaid at least one dimension of the silver nanoparticles is estimated based on the hydrodynamic diameter of the particles as measured by DLS techniques. In some embodiments, the population distribution of the particles is expressed in terms of the cumulative particle size distribution according to the number of particles in a sample. In some embodiments, the population distribution of the particles is expressed in terms of the cumulative particle size distribution of a sample volume of particles.
[0164] In some embodiments, the silver nanoparticles are present in the composition at a concentration in the range of from about 0.01 wt. % to about 10 wt. % of the total composition. In some embodiments, the silver nanoparticles are present in the composition at a concentration in the range of from about 0.01 wt. % to about 5 wt. %, from about 0.05 wt. % to about 5 wt. %, or from about 0.1 wt. % to about 2 wt. % of the total composition. In some preferred embodiments, the silver nanoparticles are present in the composition at a concentration of about 1 wt. % or about 2 wt. % of the total composition.
[0165] In some embodiments, the silver particles constitute at least 0.01 wt. %, at least 0.1 wt. %, at least 0.5 wt. %, at least 1 wt. %, at least 2 wt. %, at least 3 wt. %, at least 4 wt. %, at least 5 wt. % or at least 10 wt. % of the composition. In some embodiments, the silver particles constitute at most 10 wt. %, at most 5 wt. %, at most 4 wt. %, at most 3 wt. %, at most 2 wt. %, at most 1 wt. %, at most 0.5 wt. %, or at most 0.1 wt. % of the composition.
[0166] In some embodiments of the composition, use or method disclosed herein, the UV protective composition is a composition for human or animal use, formulated as a topical composition. The topical composition may optionally be provided in a form selected from the group consisting of a cream, an emulsion, a gel, a lotion, a mousse, a paste and a spray. If desired, the topical composition can also be formulated into make-up cosmetics, for example, foundation, blusher, etc.
[0167] In some embodiments, the topical composition further comprises a dermatologically or cosmetically or pharmaceutically acceptable carrier.
[0168] In some embodiments, the topical composition further comprises one or more dermatologically or cosmetically or pharmaceutically acceptable additives or excipients, such as colorants, preservatives, fragrances, humectants, emollients, emulsifiers, waterproofing agents, surfactants, dispersants, thickeners, viscosity modifiers, anti-foaming agents, conditioning agents, antioxidants and the like. Such additives or excipients and the concentrations at which each can effectively accomplish its respective functions, are known to persons skilled in the pertinent art and need not be further detailed.
[0169] In some embodiments, the topical composition is a sunscreen composition.
[0170] In some embodiments, the UV protective composition is in the form of a coating that can be applied to the surface of an inanimate object. The coating composition may be provided in a form selected from the group consisting of liquid coat, an emulsion, a cream, a gel, a paste and a spray.
[0171] In another aspect of the present disclosure, there is provided a method for the preparation of the compositions disclosed herein.
[0172] According to a further aspect of some embodiments of the disclosure, there is provided a UV protective composition as disclosed herein, for use in protecting a subject, such as a human subject or a non-human animal, against a harmful effect of ultraviolet radiation, in some embodiments providing broad-spectrum protection against both ultraviolet A and ultraviolet B radiation.
[0173] In some embodiments, the composition is for use in protecting the skin of a subject, against a harmful effect of ultraviolet radiation, in some embodiments providing broad-spectrum protection against both ultraviolet A and ultraviolet B radiation.
[0174] In some embodiments, the composition is for use in protecting the hair of a subject, such as a human subject, against a harmful effect of ultraviolet radiation, in some embodiments against harmful effects of both ultraviolet A and ultraviolet B radiation.
[0175] The skin may be the skin of the face, of the arms, of the legs, of the neck of the torso, or of any other area of the body that can be exposed to UV radiation.
[0176] In some embodiments, the sunscreen composition as disclosed herein is applied to the skin of the subject prior to or during exposure to UV radiation. In some embodiments, the composition is reapplied intermittently, for example every 10 hours, every 9 hours, every 8 hours, every 7 hours, every 6 hours, every 5 hours, every 4 hours, every 3 hours, every 2 hours or every hour, or any intermediate value, during exposure to UV radiation.
[0177] In some embodiments, the UV-protective composition is for protecting the hair of a subject against ultraviolet radiation and is provided in a form selected from the group consisting of a cream, an emulsion, a gel, a lotion, a mousse, a paste and a spray. In some embodiments, the composition is provided in the form of a shampoo, a conditioner or a hair mask.
[0178] In some embodiments, the composition is formulated to be applied to the hair, or is applied to the hair, for a fixed period of time (such as up to 1 minute, up to 2 minutes, up to 3 minutes, up to 4 minutes or up to 5 minutes, up to 10 minutes, up to 15 minutes, up to 20 minutes, up to 25 minutes or up to 30 minutes) prior to rinsing. In some embodiments, the conditioner or hair mask is formulated for application to the hair, or is applied to the hair without rinsing, such that the conditioner or hair mask remains on the hair.
[0179] According to a further aspect of some embodiments of the disclosure, there is provided a UV protective composition as disclosed herein, for use in protecting an inanimate object, against a harmful effect of ultraviolet radiation, in some embodiments providing broad-spectrum protection against both ultraviolet A and ultraviolet B radiation.
[0180] According to a further aspect of some embodiments of the disclosure, there is provided a method of protecting the skin or the hair of a subject against a harmful effect of ultraviolet radiation, the method comprising applying to the skin and/or the hair of the subject a sunscreen composition comprising a matrix comprising a polymer and an oil; and particles of doped or undoped BLT crystals, dispersed in the matrix.
[0181] According to a further aspect of some embodiments of the disclosure, there is provided the use of a matrix comprising a polymer and an oil; and particles of a UV protective-agent comprising doped or undoped BLT crystals, dispersed in the matrix, in the manufacture of a composition for protection of the skin and/or the hair of a subject against a harmful effect of ultraviolet radiation.
[0182] According to a further aspect of some embodiments of the disclosure, there is provided the use of a matrix comprising a polymer and an oil; and particles of a UV protective-agent comprising doped or undoped BLT crystals, dispersed in the matrix, in the manufacture of a composition for protection of exterior surfaces of an inanimate object against a harmful effect of ultraviolet radiation. The exterior surface may comprise the surface of any porous or non-porous material, including, but not limited to glass, fabrics, leathers, woods, cardboards, metals, plastics, rubbers, ceramics and other structural materials.
[0183] The composition for the protection of inanimate objects against UV radiation, can be formulated in any form suitable for application to the surface of the inanimate object on which it is to be used.
EXAMPLES
Materials and Methods
Materials
[0184] The following materials were purchased from Sigma Aldrich, USA:
TABLE-US-00001 Bi.sub.2O.sub.3 (99.9% pure) CAS 1304-76-3 Fe.sub.2O.sub.3 (99% pure) CAS 1309-37-1 La.sub.2O.sub.3 (99.9% pure) CAS 1312-81-8 Poly Acrylic Acid Sodium base (PAA) CAS 9003-04-7 TiO.sub.2 (99% pure) CAS 13463-67-7
[0185] The milling media, namely Zirconia beads having an average diameter of 2 mm, were purchased from Pingxiang Lier Ceramic Co., China.
Equipment
[0186] High Resolution Scanning Electron Microscope HSEM/TEM Magellan XHR 400L FE-SEM by Nanolab Technologies, Albany, N.Y., USA.
[0187] High Resolution X-ray diffractometer XRD Rigaku SmartLab with Cu radiation generated at 40 kV and 30 mA (CuKa=1.542 A) as the X-ray source.
[0188] Particle Size Analyzers (Dynamic Light Scattering) Zen 3600 Zetasizer (for particles in the range of up to about 10 m) and Mastersizer 2000 (for particles in the range of 0.02 m to 2000 m) by Malvern Instruments, Malvern, UK.
[0189] Oven, Vulcan-Hart 3-1750 multi-stage programmable box furnace.
[0190] Temperature controllable circulating water bath, BL-30L 9 liter HP by MRC, Hampstead, London, UK.
[0191] Grinding Mill Model HD-01 Attritor by Union Process, Inc., Akron, Ohio, USA.
[0192] Analytical Balance XSE by Mettler-Toledo International Inc., Columbus, Ohio, USA.
[0193] Mortar Grinder Pulverisette 2 by Fritsch GmbH, Idar-Oberstein, Germany.
[0194] Double Planetary Mixer by Charles Ross & Son Company, Hauppauge, N.Y., USA.
Example 1
Preparation of BLT Crystals
[0195] BLT crystals having the formula Bi.sub.(4-x)La.sub.(x)Ti.sub.(3-y)Fe.sub.(y)O.sub.12 as an ultraviolet-absorbing agent, wherein x is between 0.1 and 1.5; and wherein y is between 0 and 2 were prepared by a solid solution method. The Fe-doped crystals included five different molar ratios of Fe to Ti, as follows: 0.0625:2.9375, 0.125:2.875, 0.25:2.75, 1:2 or 1.5:1.5.
[0196] In this process, the constituent metal oxides were mixed together in powder form so as to obtain the desired stoichiometric amount. Bi.sub.2O.sub.3, having a MW of 465.96 g/mol, La.sub.2O.sub.3 having a MW of 325.82 g/mol, TiO.sub.2 having a MW of 79.87 g/mol were mixed in desired ratio so that the combined BLTO powders amounted to about 200 grams. When desired, Fe.sub.2O.sub.3 having a MW of 159.69 g/mol, was added while the amount of titanium dioxide was reduced, the amount of ferric oxide selected to provide the required doping ratio. The combination of metal oxides, which in case of intended iron doping can be termed the BLTO-Fe powders, amounted likewise to about 200 grams.
[0197] All materials were weighed using an analytical scale (Mettler Toledo, USA).
[0198] The powders of the constituent oxides were then mixed together for about 10 minutes at 70 rpm at ambient temperature in a Pulverisette 2 mortar grinder (Fritsch, Germany), so as to obtain homogeneously mixed powders (BLTO or BLTO-Fe, as appropriate). The mixed powders were transferred to a 500 ml alumina crucible and sintered or calcined by heating in a ceramic oven at a rate of 40 C. per minute until the temperature reached 1000 C., and maintaining at this temperature for 24 hours, allowing for the formation of the desired doped or undoped BLT crystals. It is believed that under such conditions, the iron atoms can substitute the titanium atoms in the orthorhombic structure of the BLT to provide doping without breaking the crystallographic symmetry.
[0199] After 24 hours at 1000 C., the samples were allowed to cool down to ambient temperature (circa 23 C.), at which time they were again ground to homogeneous powder for about 10 minutes at 70 rpm by the Pulverisette 2 mortar grinder.
[0200] Powders of doped or undoped BLT crystals prepared as above-described were either used or analyzed as is in coarse form, or further size-reduced and used and analyzed in the form of nanoparticles, as described in following examples. It is to be understood that the coarse material was manually ground with a mortar and pestle to disassociate any gross agglomerate that may be present in the resulting powders, so as to eliminate coarse lumps of particles. In bulk size, the BLT compounds displayed a pale yellow shade if undoped and a reddish tint if doped, the color intensity depending on the degree of iron doping.
Example 2
Crystal Structure Determination
[0201] The crystal structure of doped BLT crystals for a Fe:Ti substitution of 0.25:2.75 as above-prepared was determined by powder XRD using Rigaku TTRAX-III X-ray diffractometer. The X-ray source (Cu anode) was operated at a voltage of 40 kV and a current of 30 mA on packed powder samples. Data were collected in continuous detector scan mode at a step size of 0.02/step. Diffractograms were collected over the 2 range of 10 to 65. The results are shown in
Example 3
Absorbance Determination in Powder
[0202] Absorbance correlation of coarse powders over the wavelength range of 200-800 nm was calculated using a Cary 300 UV-Vis spectrophotometer with an integrated sphere detector (Agilent Technologies, Santa Clara, Calif., USA).
[0203] Briefly, the absorbance of the samples was qualitatively estimated by subtracting the amount of light reflected from the powder sample, gathered by the integrated sphere detector of the spectrophotometer, from the amount of light reflected from a white surface (which reflects all incident light). Since the extent of penetration of the light into the samples and the extent of scattering of the sample is unknown, this measurement provides an absorbance profile of the sample rather than a true quantitative measurement.
[0204] Results, showing correlation to absorbance as a function of wavelength, determined by diffuse reflection measurement gathered by the integrated sphere method, are presented in
[0205]
[0206]
Example 4
Preparation of Nanoparticles
[0207] Nanoparticles of doped or undoped BLT crystals, as well as their respective constituents and mixtures thereof when desired, were prepared from the ground samples obtained in Example 1 or from their stock powders. Generally, all such samples or stock powders contained particles having a size greater than about 5 micrometer (m) and may be referred hereinafter as the coarse materials. The coarse powders were milled in an Attritor grinding mill (HD-01 by Union Process) using a batch size of 200 g with solid loading 10% (20 g) as follows.
[0208] All materials were weighed using an analytical scale (XSE by Mettler Toledo). 20 g of PAA dispersant was weighed and dispersed in about 100 ml of deionized water. 20 g of coarse powder was weighed and introduced into the dispersant-containing liquid to provide a dispersant to inorganic material ratio of 1:1 yielding a slurry of the inorganic material. Water was added to complete batch size to 200 g, the solids constituting about 10 wt. % of the sample.
[0209] The aqueous slurry of inorganic material was then placed in a zirconia pot with 2300 g of 2 mm diameter zirconia grinding beads. The pot was placed in the grinding mill, and the grinding mill activated at 700 rpm for about 75 hours at 25 C.
[0210] The hydrodynamic diameter of the nanoparticles obtained by this method was determined by Dynamic Light Scattering, using a Zen 3600 Zetasizer from Malvern Instruments Ltd. (Malvern, UK). A sample of the milled nanoparticles was further diluted in deionized water to form a suspension having a solid concentration of about 0.5 wt. %.
[0211] Representative results, showing the percentage of number of doped and undoped BLT crystal particles having hydrodynamic diameters in the range of 1-100 nm are presented in
[0212] As shown in the figure, the particles of inorganic material in suspension had hydrodynamic diameters of up to about 100 nm. The majority of doped and undoped BLT crystal particles had hydrodynamic diameters in the size range of from about 15 nm and up to about 60 nm or 50 nm. The predominant peak of undoped BLT, was around about 26 nm, whereas the two Fe-doped variants displayed similar peaks at about 28 nm for Fe:Ti 0.25:2.75 and about 24 nm for Fe:Ti 1:2 Results of the particle size distribution of the nanoparticles prepared as herein described, namely the maximum hydrodynamic diameter of a percentage of the population, are provided in the Table 1 below, in terms of percent of number of particles.
TABLE-US-00002 TABLE 1 Max. Hydrodynamic Diameter (nm) Material 50.0% 90.0% 95.0% 97.5% 99.0% Undoped 25.6 37.0 43.1 53.0 72.0 BLT Fe:Ti 0:3 Doped 28.0 34.0 37.7 44.9 64.6 BLT Fe:Ti 0.25:2.75 Doped 24.0 33.0 36.5 43.0 68.3 BLT Fe:Ti 1:2
[0213] As can be seen from the above table, at least 99% of the nanoparticles of doped or undoped BLT as prepared and size-reduced according to the present teachings have a dimension of at most 100 nm.
Example 5
Absorbance of Suspended Crystal Nanoparticles
[0214] Absorbance of the doped and undoped BLT crystal nanoparticles prepared according to Example 4 was measured over the wavelength range of 200-800 nm using a Cary 300 UV-Vis spectrophotometer with quartz cuvette (10 mm light pathway). The samples were diluted in the vehicle in which the inorganic materials were milled (namely with deionized water containing 20 wt. % PAA) to provide any desired predetermined solid concentration (e.g., 0.125 wt. %, 0.25 wt. % and 0.5 wt. %,). Results are presented in
[0215] In
[0216] Since 0.125 wt. % of undoped BLT already provides for a significant absorbance of about 0.74 at 400 nm, the absorbance of Fe-doped BLT crystals (Fe:Ti 0.25:2.75 and Fe:Ti 1:2), is displayed in
[0217] Higher concentrations of nanoparticles of Fe-doped BLT were also tested and displayed a pattern similar to that of unsubstituted BLT, namely over the range tested a higher concentration of material led to a broader range of wavelength with efficient absorbance.
Example 6
Scanning Electron Microscope Studies
[0218] The doped and undoped BLT crystal nanoparticles were also studied by High Resolution Scanning Electron Microscopy (HR-SEM) using Magellan 400 HSEM/TEM by Nanolab Technologies.
[0219]
Example 7
Determination of Critical Wavelength
[0220] Based on the absorbance spectra determined according to previous Examples, critical wavelength was calculated for undoped BLT crystals and for two Fe-doped variants, all measured at nanoparticle concentration of 0.5 wt. % and 0.125 wt. %. A suspension of nanoparticles of Zinc Oxide at 0.5 wt. % served as control.
[0221] Briefly, in order to quantify the breadth of UV protection, the absorbance of the sunscreen composition was integrated from 290 nm to 400 nm the sum reached defining 100% of the total absorbance of the sunscreen in the UV region. The wavelength at which the summed absorbance reaches 90% absorbance was determined as the critical wavelength which provided a measure of the breadth of sunscreen protection.
[0222] The critical wavelength .sub.c was defined according to the following equation:
wherein:
[0223] .sub.c is the critical wavelength;
[0224] T() is the mean transmittance for each wavelength; and
[0225] D is the wavelength interval between measurements.
[0226] Critical wavelengths as calculated are presented in Table 2 below.
TABLE-US-00003 TABLE 2 Critical Wavelength (nm) Inorganic Material 0.125 wt. % 0.5 wt. % BLT undoped 370 390 BLT-Fe Fe:Ti 0.25:2.75 374 393 BLT-Fe Fe:Ti 1:2 378 397 ZnO Control Not Available 362
[0227] As can be seen from the above table, according to the Critical Wavelength Method, undoped and Fe-doped BLT crystal nanoparticles can be classified as providing broad spectrum protection (i.e. having a critical wavelength of 370 nm or more) at concentrations of as low as 0.125 wt. % and 0.5 wt. % Such results are superior to those achieved by the control suspension consisting of ZnO nanoparticles having similar particle size distribution when tested at the higher concentration of 0.5 wt. %.
Example 8
Preparation of Composition Comprising Polymer Matrix and BLT Crystals
[0228] The nanoparticles of doped or undoped BLT crystals prepared according to the present teachings and above-examples can be further processed so as to be embedded or immobilized within a polymer matrix. Suitable methods and polymers are described by the present Applicant in PCT Publication No. WO 2017/013633, incorporated herein by reference in its entirety as if fully set forth herein. In particular, Example 2 of the reference provides for the preparation of a polymer matrix, whereas Example 3 teaches how to blend such matrix with nanoparticles, and how to further process such mixture so as to obtain polymer embedded particles.
Example 9
Preparation of Composition Comprising BLT Crystals in Wood Lacquer
[0229] Doped and undoped BLT crystal nanoparticles are diluted in a clear wood lacquer (Tambour Clear Glossy Lacquer for Wood No. 8, Cat. No. 149-001) to a particle concentration of 1% by weight of the total lacquer composition. The resulting mixtures are sonicated for 30 seconds using a Misonix Sonicator tip (Misonix, Inc.) at amplitude 100, 15 W. The sonicated lacquer dispersions are applied upon a microscopic glass slide at an initial thickness of about 100 m (using 100 m thick spacers and a leveling rod). The lacquer coated slides are left to dry for at least 12 hours at ambient temperature (circa 23 C.) resulting in a dried layer of sample of about 5 m. The lacquer devoid of added nanoparticles serves as control. Absorbance of the dried layers of lacquer over the wavelength range of 200-800 nm is assessed using a Cary 300 UV-Vis spectrophotometer.
Example 10
Non-Aqueous Compositions Comprising Doped BLT Crystals
[0230] The Fe doped BLT crystals were prepared as described in Examples 1 to 3.
Preparation of Nanoparticles
[0231] Nanoparticles of doped BLT crystals were prepared from the ground samples obtained in Example 1. Generally, all such samples contained particles having a size greater than about 5 micrometer (m) and may be referred hereinafter as the coarse materials. The coarse powders were milled in an Attritor grinding mill (HD-01 by Union Process) using a batch size of 300 g with solid loading 10% (30 g) as follows.
[0232] All materials were weighed using an analytical scale (XSE by Mettler Toledo). 30 g of polyhydroxystearic acid (commercially available from Innospec Performance Chemicals as Dispersun DSP-OL100 or Dispersun DSP-OL300) dispersant was weighed and dispersed in about 100 ml of Isopar L of ExxonMobil Chemicals or C12-C15 alkyl benzoate (commercially available from Phoenix Chemical as Pelemol 256). 30 g of coarse powder of Fe-doped BLT was weighed and introduced into the dispersant-containing liquid to provide a dispersant to inorganic material weight per weight ratio of 1:1 yielding a slurry of the inorganic material. Isopar L or C12-C15 alkyl benzoate was added to complete batch size to 300 g, the solids constituting about 10 wt. % of the sample.
[0233] The oily slurry of inorganic material was then placed in a zirconia pot with 2300 g of 2 mm diameter zirconia grinding beads. The pot was placed in the grinding mill, and the grinding mill activated at 700 rpm for about 75 hours at 25 C.
[0234] The hydrodynamic diameter of the milled particles was determined by Dynamic Light Scattering, using a Malvern Nano ZS Zetasizer particle size analyzer. A sample of the milled nanoparticles was further diluted in Isopar L to form a suspension having a solid inorganic concentration of about 0.1 wt. % for the sake of such measurements. Representative results, showing the hydrodynamic diameters of Fe-doped BLT particles, having Fe:Ti doping of 1:2 or 0.25:2.75, expressed in terms of percentage of number of particles in the range of 10-1,000 nm are presented in
[0235] As shown in
TABLE-US-00004 TABLE 3 Max. Hydrodynamic Diameter Material D.sub.N10 D.sub.N50 D.sub.N90 BLT 1:10 58.0 nm 79.5 nm 138.0 nm BLT 1:2 84.3 nm 128.0 nm 256.0 nm
[0236] As the above dynamic light scattering measurements, which assume, for the sake of hydrodynamic diameter calculations, that the particles are perfect spheres tend to overestimate the actual size of the particles, in particular if non-spherical, the size of the particles of Fe-doped BLT was further assessed by STEM microscopy.
11Example
Preparation of Composition Comprising Swelled Polymer Matrix Macroparticles and Nanoparticles UV-Protective Agent
[0237] 2 weight portions of a swelled polymer matrix (consisting of Nucrel 699 and Isopar L), prepared as described in Example 3 of WO 2017/013633 to the same Applicant, were mixed with 1 weight portion of non-aqueous dispersions containing 10 wt. % inorganic nanoparticles of UV-protective agents, Fe-doped BLT having a Fe:Ti ratio of 1:2 or 0.25:2.75, prepared as described in Example 10. The oil dispersions used herein are those which served for the measurements illustrated in
[0238] 200 g of the resulting mixture were placed in a zirconia pot, 2,500 g of zirconia beads of about 2.38 mm ( 3/32) diameter were added to the pot, and the pot was placed in the grinding mill. The temperature of the pot was maintained at 25 C. while the grinding mill was set to mill the contents of the pot at 700 rpm for 12 hours resulting in a composition according to the teachings herein comprising inorganic nanoparticles of UV-protective agent dispersed and embedded in the swelled polymer matrix macroparticles.
[0239] The hydrodynamic diameters of the resulting macroparticles of swelled polymer matrix were determined using Malvern Mastersizer 2000. The percentage (per volume) of macroparticles of polymer embedding the BLT-Fe doped nanoparticles are presented in
[0240] The absorbance of the non-aqueous dispersions of polymer embedded Fe-doped BLT composite lotions was measured as described in Example 3 with the following modifications. The dispersions were spread between two quartz slides (76.225.41.0 mm) and their absorbance over the wavelength range of 200-800 nm was assessed using a Cary 300 UV-Vis spectrophotometer. The results are presented in
[0241] Certain marks referenced herein may be common law or registered trademarks of third parties. Use of these marks is by way of example and shall not be construed as descriptive or limit the scope of this disclosure to material associated only with such marks.
[0242] Although the disclosure has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims.
[0243] Citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the disclosure.