Transparent sunscreen with high UVA protection

Description

[0001] The present invention relates to an alcohol-based cosmetic transparent sunscreen spray without film-forming polymers and octocrylene, but with the water-soluble sunscreen filter phenylbenzimidazolesulfonate, excluding the denaturant methyl ethyl ketone, in particular in the form of a pump spray or an aerosol spray. Background of the invention

[0002] The present invention relates to a cosmetic, transparent preparation with a light protection filter as a sunscreen for human skin.

[0003] For decades, people in many parts of the world have exposed themselves to solar radiation, as this stimulates melanin production and tans the skin. However, the sun's ultraviolet radiation also has a damaging effect on the skin. In addition to acute damage, such as sunburn, long-term consequences like an increased risk of skin cancer and premature skin aging can also occur.

[0004] To protect the skin, a number of sunscreen filters have been developed for use in cosmetic preparations. The UVA, UVB, and broadband sunscreen filters that can be used are listed in particular in the European Cosmetics Regulation (EC) No 1223 / 2009.

[0005] These sunscreens are commercially available in a wide variety of cosmetic formulations to offer users sun protection for diverse situations (sports, sunbathing, and other leisure activities) and for different body parts (face, eye area, lips, and the entire body). This has led to the development of applications such as creams, fluids, lotions, milks, aerosol foams, emulsion sprays – even wipes and lipsticks containing sunscreen are available commercially.

[0006] In recent years, sunscreen sprays have become increasingly popular with consumers, primarily due to their ease of application. For leisure and sports activities, an even more specialized type has gained traction: the transparent alcoholic sunscreen spray. This newer application method is a solution rather than an emulsion, making it particularly easy to spread on the skin and leaving a minimal stickiness. The stickiness often criticized by users in sunscreen products is therefore significantly reduced with this application method.

[0007] However, these transparent alcoholic sunscreen sprays or gels also have a disadvantage. The absence of UV-absorbing pigments like titanium dioxide limits the choice of UV filters. Therefore, only soluble UV filters can be used. Within the limits of officially approved concentrations of these UV filters, achieving high sun protection factors while simultaneously providing high to very high UVA protection is difficult.

[0008] Transparent sunscreen sprays that are intended to offer both a high sun protection factor (SPF) and high UVA protection currently require, on the one hand, a very high concentration of oil-soluble UV filters. On the other hand, they require the addition of a film-forming polymer, which is considered essential for creating a homogeneous protective film at high SPF levels. The film-forming, but sticky, UV filter octocrylene is also very frequently used in current technology to support the formation of a uniform, yet sticky film on the skin. At the same time, octocrylene supports the necessary photostability of the UVA filters, particularly avobenzone.

[0009] WO 2007 / 068699 A1 describes in detail the existing structure of transparent alcoholic sprays and gels. These are presented as alcoholic solutions with organic, oil-soluble UV filters and film-forming polymers, such as acrylate / octylacrylamide copolymer, carbomer, or acrylate / C10-30 alkyl acrylate crosspolymer, also illustrated with numerous examples.

[0010] In recent years, however, the UV filter octocrylene and the film-forming synthetic, often acrylate-based polymers (synthetic polymer) have come under public scrutiny. Octocrylene, on the one hand, because studies suggest that potentially carcinogenic benzophenone derivatives are formed during storage, and the synthetic polymer, on the other hand, because it is considered potentially harmful to aquatic life.

[0011] Light, easily absorbed and non-sticky alcoholic transparent sprays with a high sun protection factor and high UVA protection are of particular interest to people with fair skin or to older people with actinic keratosis, as this user group has not previously had access to this advantageous type of transparent alcoholic spray without a sticky film.

[0012] The object of the present invention is therefore to eliminate this deficiency of the prior art and to create an alcohol-transparent cosmetic preparation which enables a high sun protection factor with simultaneously high UVA protection, without the use of film formation, i.e., without the undesirable ingredients octocrylene and without synthetic polymer.

[0013] This problem is solved according to the invention by providing a transparent, alcohol-based cosmetic sunscreen composition comprising 0.1 to 3%, based on the total preparation, of the UV filter phenylbenzimidazolesulfonate, at least one cosmetically acceptable oil dissolved in ethyl alcohol, with a water content of 0.1 to 10%, based on the total preparation, and wherein the composition is free of octocrylene and film-forming synthetic polymer and free of the denaturant methyl ethyl ketone (MEK). Preferably, the phenylbenzimidazolesulfonate is produced by aqueous neutralization of the phenylbenzimidazolesulfonic acid in water.

[0014] Utility model DE 20 2010 006 005.2 is in the present field, but differs from the present invention by its film-forming application with polymers and octocrylene. Furthermore, in this description, the use of MEK-denatured alcohol can result in an unpleasant odor, which can only be counteracted and eliminated by a very low dosage of phenylbenzimidazolesulfonate and strong perfume.

[0015] Surprisingly and unexpectedly for those skilled in the art, the present invention makes it possible to achieve a high sun protection factor with simultaneously high and sufficiently photostable UVA protection without any polymer-based film formation. Furthermore, by using undenatured ethanol or ethanol denatured only with isopropyl alcohol, the formation of the unpleasant odor was surprisingly prevented even at higher concentrations of phenylbenzimidazolesulfonate (0.5-3%).

[0016] The composition according to the invention is transparent. A composition according to the invention is considered transparent if it is possible to see through a disposable cuvette (Brand company, 2.5 ml, wavelength range: 220 nm–900 nm) filled with the composition according to the invention with the naked eye in daylight. Text (Anal font, size 8) located directly behind the disposable cuvette must be clearly visible and legible. According to the invention, the composition preferably contains 30 to 85 wt.% ethanol and most preferably 50 to 80 wt.% ethanol, in each case based on the total weight of the preparation. The water content of the composition according to the invention is preferably less than 10%, more preferably less than 3% but at least 0.1%. The composition may additionally contain 1 to 50% isopropyl alcohol.

[0017] In a preferred embodiment of the invention, the composition contains 10 to 45 wt.% of oil components that are liquid at 20°C and, most preferably, 15 to 45 wt.% of oil components that are liquid at 20°C, in each case based on the total weight of the composition.

[0018] In a further embodiment of the invention, the oil components that are liquid at 20°C can be selected from the group of compounds C12-15-alkyl benzoate, butylene glycol dicaprylate / dicaprate, octyldodecanol, phenethyl benzoate, cocoglyceride, isopropyl palmitate, ethylhexyl stearate, dicaprylyl ether, dicaprylyl carbonate, undecane, tridecane, dimethicone, alkyl dimethicone, caprylic / capric triglyceride.

[0019] It is preferred in accordance with the present invention if the liquid care components glycerin with 2-10%, and vitamin E derivatives, such as tocopheryl acetate with 0.2 to 2% and / or panthenol with 0.2 to 2%, are used as further care components in the composition.

[0020] Preferably, the composition further comprises at least one additional oil-soluble UV filter. Particularly advantageous additional oil-soluble UV filters used in accordance with the present invention are: butyl methoxydibenzoylmethane (avobenzone), ethylhexyl salicylate (EHS), diethylhexyl butamidotriazone (DBT), 2,4-bis-{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine (INCI: Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine) (BEMT), ethylhexyl triazone (EHT), and diethylamino hydroxybenzoyl hexyl benzoate (DHHB). Furthermore, all other oil-soluble UV filters listed in Annex VI of the Cosmetics Regulation (EC) No 1223 / 2009 can also be used. Avobenzone is preferred.

[0021] A preparation of the invention is preferred which has a UVA / UVB ratio of at least 0.7 or more, preferably at least 0.9 or more.

[0022] In contrast to the conventional prior art and the sunscreen described in WO 2007 / 068699, it is not advantageous in the context of this invention to use the UV filters titanium dioxide or zinc oxide, as this leads to a loss of the desired transparency of the sunscreen. The preparation is therefore preferably free of titanium dioxide and / or zinc oxide.

[0023] To neutralize 2-phenylbenzimidazole-5-sulfonic acid (INCI: Phenylbezimidazole sulfonic acid: PBSA), aminomethylpropanol, aqueous sodium hydroxide solution, or aqueous potassium hydroxide solution can advantageously be used in accordance with the invention. Other amines, such as tetrahydroxypropyl ethylenediamine, can also be used for this purpose.

[0024] Another aspect of the present invention therefore relates to a method for producing a cosmetic composition according to the invention, comprising a suitable formulation of the ingredients of the cosmetic composition as described herein, further comprising the step of producing the phenylbenzimidazolesulfonate by aqueous or alcoholic neutralization of the phenylbenzimidazolesulfonic acid prior to assembly / formulation.

[0025] According to the invention, the advantageous concentration of PBSA used is between 0.1 wt.% and 5 wt.%, particularly advantageous between 0.3 wt.% and 3 wt.% and most advantageous between 0.3 wt.% and 1.5 wt.% based on the cosmetic preparation.

[0026] Other ingredients used according to the invention include organosiloxanes such as cyclomethicone or dimethicone, conditioning agents such as vitamin E, vitamin C, vitamin A or their derivatives, as well as other excipients such as propylene glycol, isopropyl alcohol or liquid emulsifiers. Other ingredients such as Ronacare AP or ubiquinone, flavonoids or anti-wrinkle agents such as tripeptides or ectoin are also not limiting within the meaning of the present invention.

[0027] According to the invention, it is advantageous if the cosmetic dosage form is an alcoholic spray. It is further advantageous if the preparation according to the invention is to be applied as a spray with a pump atomizer or as an aerosol with one or more propellants selected from the group consisting of propane, butane, isobutane, pentane / isopentane, or dimethyl ether (DME). Furthermore, it is advantageous according to the invention to provide the spray in the form of a bag-on-valve aerosol. It is also advantageous according to the invention if the cosmetic dosage form is an aerosol spray with one or more of the propellants propane, butane, isobutane, pentane, isopentane, or dimethyl ether.

[0028] Another aspect of the present invention relates to the composition according to the invention for use in the prevention or treatment of UV-based skin damage, such as sunburn or skin cancer, as well as actinic keratosis or premature skin aging, comprising the topical application of an effective amount of the composition to the skin of a mammal, in particular a human. In particular, compliance is increased by the advantageous composition of the product, while maintaining protection.

[0029] The following example according to the invention is intended to illustrate the present invention without limiting it. Unless otherwise stated, all quantities, proportions, and percentages are based on the weight and total quantity or total weight of the preparations.

[0030] To further clarify the advantage of the invention; it is preferably a transparent sunscreen spray with a high sun protection factor of 50 (determined in vivo: 55) with a UVA / UVB ratio of 0.92, thus meeting the high UVA protection criteria of the Boots Star rating (5 stars).

[0031] The UVA / UVB ratio can typically be determined as follows. 0.75, 1.0, or 1.3 mg / cm² (depending on the method) of the composition to be tested is applied to a suitably roughened substrate (verified by a profilometer). After controlled distribution, the sample is dried for at least 15 or 30 minutes. Then, the first UV absorbance measurement is performed for the various plates using a spectrophotometer (UV analyzer) to calculate the sun protection factors for UV dose-exposure calculation (if required). Afterward, the samples are exposed to UV light from a calibrated solar simulator, which delivers a precise dose (verified using a radiometer) (UV source verified using a spectrophotometer), and then a second UV absorbance measurement is performed.The UVA / UVB ratio (Boots Star rating system) is then finally calculated from the ratio of the mean UVA absorption to the mean UVB absorption, both defined by the area (per unit wavelength) of the respective UV part from the same curve.

[0032] Other provisions can be found as in Pelizzo et al. (In vitro evaluation of sunscreens: an update for the clinicians. ISRN Dermatol. 2012;2012:352135. doi:10.5402 / 2012 / 352135) e.g. according to COLIPA 2011 / FDA Final Rule 2011 using UV / Vis LAMBDA spectrophotometers. Example:

[0033] Transparent sun spray SPF 50 / UVA / UVB = 0.92 raw material % by weight 1 Alcohol Denat. (IPA / TB without MEK) 53,7 2 Glycerin 3 3 DHHB 3,5 4 K-Phenylbenzimidazolesulfonate 0,8 5 Water 0,5 6 Potassium hydroxide, 30% (KOH) 0,3 7 BEMT 2,8 8 Avobenzone 4,9 9 EHS 4,9 10 C12-15 Alkyl Benzoate 18 11 Dicaprylyl Ether 5 12 Ethylhexyl triazone 2,2 13 DBT 0,2 14 Vitamin E acetate 0,2 100

Claims

1. Transparent cosmetic sun protective composition on an alcoholic basis, comprising, from 0.1 to 3 wt % with respect to the overall composition of the UV filter phenylbenzimidazole sulfonate, at least one cosmetically acceptable oil, dissolved in ethyl alcohol, having a water content of 0.1 % up to 10 wt % with respect to the overall composition, wherein the composition is free from octocrylene and film forming synthetic polymer and is free from the denaturant methyl ethyl ketone (MEK).

2. Cosmetic composition according to claim 1, further comprising an additional oil-soluble UV-filter, preferred Avobenzone.

3. Cosmetic composition according to claim 1 or 2, further comprising glycerin, vitamin E acetate and / or panthenol.

4. Cosmetic composition according to any one of the preceding claims, having an UVA / UVB-ratio of at least 0.7 or more, preferably of at least 0.9 or more.

5. Cosmetic composition according to any one of the preceding claims, wherein the cosmetic administration form is an alcoholic spray.

6. Cosmetic composition according to any one of the preceding claims, wherein the cosmetic administration is an aerosol spray with one or several of the propellants propane, butane, isobutane, pentane, isopentane or dimethylether.

7. Cosmetic composition according to any one of the preceding claims, wherein the phenylbenzimidazole sulfonate is produced through an aqueous or alcoholic neutralization of phenylbenzimidazole sulfonic acid.

8. Method for producing a cosmetic composition according to any one of the preceding claims, comprising a suitable formulating of the ingredients of the cosmetic composition as described herein, and further comprising the step of producing the phenylbenzimidazole sulfonate through an aqueous or alcoholic neutralization of phenylbenzimidazole sulfonic acid before the formulation.

9. Cosmetic composition according to any one of the preceding claims 1 to 7 for use in the prevention or treatment of UV-based skin damage, such as sunburn or skin cancer as well as actinic keratosis or premature skin ageing in a mammal, in particular a human.