Patent Application
20080019929
The present invention relates to topically applicable water-in-oil (w/o) or water-in-silicone (w/Si) formulations, in particular, to new UV-protection formulations which comprise a micronised UV absorber, wherein the micronised UV absorber is combined with specific fatty acid alcohol.
It has long been known that prolonged exposure to UV radiation can lead to the formation of erythemas or light dermatoses, as well as to an increased incidence of skin cancers, or accelerated skin ageing.
Various sunscreen formulations have been proposed which include materials which are intended to counteract UV radiation, thereby inhibiting the said undesired effects on the skin.
A great number of compounds have been proposed for use as UV protectants in sunscreen formulations, especially soluble organic UV absorbers and insoluble micronised inorganic compounds, in particular zinc oxide and titanium dioxide.
With respect to the use in sunscreen formulations of soluble organic UV absorbers, they have the disadvantages that their effectiveness as UV protectants in terms of SPF (Sun Protection Factor) in a sunscreen formulation is often too low for commercial purposes; as a result of their solubility, they exhibit relatively high allergenic potential; and that as a result of intrinsic photochemical lability, the duration of the protective effect is often too low.
The high specific weight of insoluble inorganic compounds, such as titanium dioxide leads to a reduced stability of formulations containing them. Moreover, such inorganic compounds have been claimed to generate toxic radicals under the influence of light and water (“Redox Mechanisms in Heterogeneous Photocatalysis”, Serpone et al, Electrochemistry in Colloids and Dispersions, Editors Mackay and Texter, VCH Publishers Inc., New York 1992).
In GB-A-2303549, there is described a method of producing micronised, insoluble organic UV absorbers, as well as a sunscreen composition comprising a micronised formulation of an insoluble organic UV absorber, produced according to the said method.
Micronised insoluble organic When the so obtained UV absorbers are used in sunscreen formulations they provide excellent UV protection and have an SPF rating which is at least as high as corresponding sunscreen formulations containing a known inorganic UV absorber. Unlike the latter UV absorbers micronised insoluble organic UV absorbers show no tendency for generating radicals which could damage or sensitise human skin under the influence of light.
In WO 99/66896 a micronised organic UV absorber sun screen composition is disclosed, wherein the micronised organic UV absorber is present in the oil phase of the formulation.
Surprisingly it was found that the combination of a micronized organic UV absorber and a specific fatty alcohol allows a maximum of miscibility of micronized organic particles within the continuous oil phase of w/o emulsions wherein the micronized particles are stabilized in the oil phase of the composition. Simultaneously the crystal growth of micronized organic UV absorbers within W/O emulsions is limited or even eliminated.
Therefore, the present invention relates to a topically applicable water-in-oil (w/o) or water-in-silicone (w/Si) formulation comprising:
Suitable organic UV absorber (c1) may be, e.g. a triazine, a benzotriazole, a benzophenone, a vinyl group-containing amide, a cinnamic acid amide or a sulfonated benzimidazole UV absorber.
A preferred class of triazine compounds is that having the formula
Preferred compounds of formula (1) are those, wherein
Most preferred triazine derivatives are compounds of formula
Furthermore, triazine derivatives of formula
are preferred, wherein
Most preferred as component (c1) are triazine derivatives of formula
Further preferred triazine derivatives according to component (c1) correspond to formula
Further preferred triazine derivatives according to component (c1) are compounds of formulae
the formula
in which
Uppermost of interest are compounds of the formulae (5e) and (5f), in which
Very particularly preferred in this case are triazine compounds of the formula (5e)-(5h), in which R27 and R28 have the same meaning.
Furthermore, interesting triazines correspond to the formula
in which
Preferred compounds correspond to the formula
Further preferred triazine derivatives according to component (c1) are those compounds having one of the formulae
as well as 2,4,6-tris(diisobutyl-4′-aminobenzalmalonate)-s-triazine and 2,4-bis(diisobutyl-4-aminobenzalmalonate)-6-(4′-aminobenzylidenecamphor)-s-triazine.
Particularly preferred compounds of formula (1) are those having the formula:
In relation to the compounds of formula (28), when R37, R38 and R39 is an alkali metal it is preferably potassium or, especially sodium; when R37, R38 and R39 is a group N(R40)4 in which R30 has its previous significance, it is preferably a mono-, di- or tri-C1-C4alkylammonium salt, a mono-, di- or tri-C2-C4alkanolammonium salt or a C1-C3alkyl ester thereof; when R40 is a C1-C3alkyl group, it is preferably a C1-C2alkyl group, more preferably a methyl group; and when R30 is polyoxyethylene group, this preferably contains from 2-6 ethylene oxide units.
One preferred class of triazole micronised organic UV absorbers is that having the formula
A further preferred class of triazole micronised organic UV absorbers corresponds to the formula
T2 has its previous significance.
A still further preferred class of triazole micronised organic UV absorbers corresponds to the formula
A preferred class of vinyl group-containing amide micronised organic UV absorbers corresponds to the formula:
Preferred compounds of formula (32) are 4-methyl-3-penten-2-one, ethyl-3-methylamino-2-butenoate, 3-methylamino-1-phenyl-2-buten-1-one and 3-methylamino-1-phenyl-2-buten-1-one.
A preferred class of cinnamic acid amide micronised organic UV absorbers corresponds to the formula:
A preferred class of sulfonated benzimidazole micronised organic UV absorbers corresponds to the formula
Further preferred classes of micronised or micronisable UV absorbers used for the present invention are:
Fatty alcohols are generally understood as saturated or unsaturated primary alcohols (1-al-kanols) having 6 to 22 carbon atoms. They are obtained by reduction of triglycerides, fatty acids or fatty acid methyl esters.
Preferably the fatty alcohol according to component (c2) is a linear or linear branched C8-C20alcohol.
The fatty alcohols according to component (c2) are preferably characterized by primary alcohols which correspond to the formula
Examples of fatty alcohols according to component (c2) correspond to the formula
The fatty alcohols according to component (c2) in the composition of the present invention may be used as single compounds or as mixtures of 2 or more than 2 single compounds.
Preferably, mixtures of linear octanol and linear decanol are used as component (c2).
Preferred combinations of insoluble micronized organic UV-screening actives (component (c1) and primary C6-C28 fatty alcohols (component (c2)) are:
The micronised organic UV absorber, component (c1), is preferably produced by the method described in GB-A-2303549, namely by a process which comprises grinding the corresponding organic UV absorber, in coarse particle form, in a grinding apparatus, in the presence of 1 to 50%, preferably 5 to 40% by weight, based on the micronised organic UV absorber, of an alkyl polyglucoside having the formula CnH2n+1O(C6H10O5)xH, in which n is an integer ranging from 8 to 16 and x is the mean polymerisation level of the glucoside moiety (C6H10O5) and ranges from 1.4 to 1.6, or an ester thereof.
Any known process suitable for the preparation of microparticles can be used for the preparation of the micronised UV absorbers, for example wet-milling, wet-kneading, spray-drying from a suitable solvent, by the expansion according to the RESS process (Rapid Expansion of Supercritical Solutions), by reprecipitation from suitable solvents, including supercritical fluids (GASR process=Gas Anti-Solvent Recrystallisation/PCA process=Precipitation with Compressed Anti-solvents).
The micronised UV absorbers so obtained usually have an average particle size from 0.02 to 2, preferably from 0.03 to 1.5, and more especially from 0.05 to 1.0 micrometer.
The UV absorbers according to component (c1) can also be used as dry substrates in powder form
The topically applicable water-in-oil (w/o) or water-in-silicone (w/Si) formulation according to the present invention may additionally contain one or more than one further non-micronized UV filter as listed in Tables 1 and 2.
The UV absorbers as described in Tables 1 and 2 below may be added to the topically applicable water-in-oil (w/o) or water-in-silicone (w/Si) formulations according to the present invention in a amounts from 0.1 to 20% b.w. Mixtures of these UV absorbers can be used, inter alia, to improve the solubility or to increase UV absorption.
The topically applicable formulations of the present invention comprise at least a water phase and an oil-phase.
They are preferably formulated as water-in-oil (w/o) or water-in-silicone (w/Si) emulsions or microemulsions.
They may contain low molecular weight emulsifiers selected from non-ionic, cationic, amphoteric and anionic emulsifiers from 0.1 to 20% bw.
The UV-photoprotecting composition (c) is prepared by incorporating the primary C6-C28 fatty alcohol (componente (c2)) into the UV absorber dispersion which contains the micronized UV absorber by simply mixing the 2 components.
The so obtained UV-photoprotecting composition (c) is preferably incorporated into the oil phase of the W/O emulsion.
The simple adding of such UV-photoprotecting composition helps to stabilize or even eliminate the crystal growth of the selected micronized organic UV-screening agent within the oil phase of the W/O or W/Si emulsion, or int the Si-phase of the w/Si emulsion respectively.
The final W/O or W/Si formulations according to the present invention may exist in a wide variety of presentation forms, for example:
Of special importance as cosmetic preparations for the skin are light-protective preparations, such as sun milks, lotions, creams, oils, sunblocks or tropicals, pretanning preparations or after-sun preparations, also skin-tanning preparations, for example self-tanning creams. Of particular interest are sun protection creams, sun protection lotions, sun protection milk and sun protection preparations in the form of a spray.
Of special importance as cosmetic preparations for the hair are the above-mentioned preparations for hair treatment, especially hair-washing preparations in the form of shampoos, hair conditioners, hair-care preparations, e.g. pretreatment preparations, hair tonics, styling creams, styling gels, pomades, hair rinses, treatment packs, intensive hair treatments, hair-straightening preparations, liquid hair-setting preparations, hair foams and hairsprays. Of special interest are hair-washing preparations in the form of shampoos.
As water- and oil-containing emulsions or microemulsions the preparations contain, for example,
The topically applicable water-in-oil (w/o) or water-in-silicone (w/si) formulation may also contain one or one more additional compounds as esters of fatty acids,natural or synthetic triglycerides including glyceryl esters and derivatives, pearlescent waxes, hydrocarbon oils, silicones or siloxanes (organosubstituted polysiloxanes), fluorinated or perfluorinated oils, super-fatting agents, surfactants, consistency regulators/thickeners and rheology modifiers, polymers, biogenic active ingredients, deodorising active ingredients, anti-dandruff agents, antioxidants, hydrotropic agents, preservatives and bacteria-inhibiting agents, perfume oils, colourants, insect repellents or polymeric beads or hollow spheres as spf enhancers.
Cosmetic or pharmaceutical formulations are contained in a wide variety of cosmetic preparations like skin-care preparations, bath preparations, cosmetic personal care preparations, foot-care preparations, light-protective preparations, skin-tanning preparations, depigmenting preparations, insect-repellents, deodorants preparations for cleansing and caring for blemished skin, e.g. synthetic detergents (solid or liquid), peeling or scrub preparations or peeling masks; hair-removal preparations in chemical form (depilation),—shaving preparations, fragrance preparations, cosmetic hair-treatment preparations,
The cosmetic preparation according to the invention is distinguished by excellent protection of human skin against the damaging effect of sunlight.
Manufacturing instruction: Heat separately part A to 80° C. and B to 80° C. Slowly add part B to part A under high stirring. Decrease the speed till moderate stirring 500 rpm. Let cool down to 35° C. and add part C.
Manufacturing instruction: Heat part A and part B separately to 80 C under stirring. Add part B to part A with continuous stirring. Homogenize for 30 sec with Ultra Turrax at 11000 rpm. Let cool down to 40° C. and add part C. Cool down to room temperature under continuous stirring.
* measurement made on Labsphere UV Transmittance Analyzer 1.2 μl/cm2 on PMMA
Manufacturing instruction: Heat phase A to 75° C. Add part B to part A and homogenize for 30 sec. at 11000 rpm. Let cool down to 50° C. and add part C. Continuous stirring until room temperature.
| Number | Date | Country | Kind |
|---|---|---|---|
| 04104185.6 | Sep 2004 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP05/54225 | 8/29/2005 | WO | 2/26/2007 |
