TOPICAL COMPOSITION

Abstract

The present invention relates to topical compositions comprising at least one liquid UV-filter and a nano-sized 1,4-di(benzoxazol-2-yl)benzene.

Claims

1. A topical composition comprising a substance which absorbs light in the UVB and/or UVA range and which is liquid at ambient temperature (UV-filter oil), wherein the composition further comprises a nano-sized 1,4-di(benzoxazol-2-yl)benzene having a mean particle size D.sub.n50 determined by laser diffraction of less than 1000 nm, preferably of less than 500 nm, most preferably of less than 400 nm.

2. The topical composition according to claim 1, wherein the amount of the at least one UV-filter oil is selected in the range from 0.1 to 30 wt.-%, more preferably in the range from 1 to 25 wt.-%, most preferably in the range from 5 to 20 wt.-%.

3. The topical composition according to claim 1, wherein the amount of the nano-sized 1,4-di(benzoxazol-2-yl)benzene is selected in the range from 0.1 to 20 wt.-%, preferably in the range from 0.2 to 15 wt.-%, most preferably in the range from 0.3 to 10 wt.-%, based on the total weight of the topical composition.

4. The topical composition according to claim 1, wherein the at least one UV-filter oil is selected from the group consisting of octyl methoxycinnamate, homosalate, ethylhexyl salicylate, octocrylene, polysilicone-15, diethylhexyl 2,6-naphthalate, diethylhexyl syringylidene malonate and benzotriazolyl dodecyl p-cresol as well as mixtures thereof, preferably of octyl methoxycinnamate, homosalate and/or ethylhexyl salicylate.

5. The topical composition according to claim 1, wherein the nano-sized 1,4-di(benzoxazol-2-yl)benzene has a mean particle size D.sub.n50 determined by laser diffraction selected in the range from 50 to 300 nm, more preferably in the range from 120 to 280 nm, most preferably in the range from 150 to 220 nm.

6. The topical composition according to claim 1, wherein the nano-sized 1,4-di(benzoxazol-2-yl)benzene is 1,4-di(benzoxazol-2-yl)benzene in a solid amorphous form.

7. The topical composition according to claim 1, wherein the nano-sized 1,4-di(benzoxazol-2-yl)benzene is incorporated into the topical composition in the form of an aqueous dispersion containing nano-sized particles of 1,4-di(benzoxazol-2-yl)benzene.

8. The topical composition according to claim 1, wherein the topical composition is an emulsion containing an oily phase and an aqueous phase.

9. The topical composition according to claim 1, wherein the amount of the oily phase is at least 10 wt.-%, based on the total weight of the topical composition.

10. The topical composition according to claim 1, wherein the amount of the oily phase is selected in the range from 10 to 60 wt.-%, preferably in the range from 15 to 50 wt.-%, most preferably in the range from 15 to 40 wt.-%, based on the total weight of the topical composition.

11. The topical composition according to claim 1, wherein the topical composition is in the form of an oil-in-water (O/W) emulsion comprising an oily phase dispersed in an aqueous phase in the presence of an O/W emulsifier.

12. The topical composition according to claim 11, wherein the O/W emulsifier is a phosphate ester emulsifier.

13. The topical composition according to claim 12, wherein the phosphate ester emulsifier is a cetyl phosphate.

14. Use of a nano-sized 1,4-di(benzoxazol-2-yl)benzene having a mean particle size D.sub.n50 determined by laser diffraction of less than 1000 nm, preferably of less than 500 nm, most preferably of less than 400 nm to reduce the transfer UV-filter oil(s) contained in a topical composition to a surface.

15. Method to reduce the transfer of liquid UV-filter oil(s) to a surface such as in particular to a glass or plastic surface, said method encompassing the addition of a nano-sized 1,4-di(benzoxazol-2-yl)benzene having a mean particle size D.sub.n50 determined by laser diffraction of less than 1000 nm, preferably of less than 500 nm, most preferably of less than 400 nm into a topical composition comprising such liquid UV-filter oil(s).

Description

EXAMPLES

1. Preparation of Nano-Sized 1,4-di(benzoxazol-2-yl)benzene

[0115] 1.1 General Methods:

[0116] All particles sizes have been determined by laser diffraction with a Malvern Mastersizer 2000 according to the method as outlined in ISO 13320:2009 and/or a Coulter Delsa Nano S (dynamic laser scattering).

[0117] Differential scanning calorimetry (DSC) was performed using Mettler Toledo DSC1 (temperature range from 25 C. to 400 C.; heating rate: 4 C./min; air atmosphere, 2-3 mg samples, average from 2 measurements).

[0118] X-ray diffraction patterns were recorded using a Bruker D8 Advance powder X-ray diffractometer in reflection (Bragg-Brentano) geometry. The PXRD diffractometer was equipped with a LynxEye detector. The samples were generally prepared without any special treatment other than the application of slight pressure to get a flat surface. Silicon single crystal sample holder for polymorph screening, 1.0 mm depth. Samples were measured uncovered. The tube voltage was 40 kV and current was 40 mA. A variable divergence slight was used with a 3 window. The step size was 0.02 2 with a step time of 37 seconds. The samples were rotated at 0.5 rps during the measurement.

[0119] E 1/1 values were determined with a UV/(vis) spectrometer (Perkin Elmer Lambda 650S) at 320 nm and a baseline correction according to the following formula: E 1/1=(E 1/1@320 nm)(E 1/1@650 nm).

[0120] The UVB:UVA ratio was determined by measuring the UV-spectra of the respective micronized UV-filter dispersed in water at a concentration of 0.001% (w/v) active and calculating the ratio by dividing the area-% from 290 to 319 nm (UVB) through the area-% from 320 to 400 nm (UVA).

1.2 Preparation of Coarse Particles of Solid Amorphous 1,4-di(benzoxazol-2-yl)benzene (DBO-400 (A))

[0121] A mixture of 702 g polyphosphoric acid and 4.28 ml methanesulfonic acid was heated to 90 C. 65 g terephthalic acid and 107 g 2-aminophenol were added. The mixture was stirred under inert atmosphere at 180 C. for 8 hours and then transferred to ice water. The precipitated product was filtered and washed with water and acetic acid. The precipitate was dispersed in water and the pH adjusted to 8.0 with sodium hydroxide, filtered and washed with water. The crude product was suspended in a mixture of toluene and 1-butanol 3.3:1, stirred at 85 C. for one hour, filtered, washed with diethyl ether, and dried. The resulting coarse particles of solid amorphous 1,4-di(benzoxazol-2-yl)benzene exhibited a particle size Dn50 of 380 nm (Malvern).

1.3 Preparation of an Aqueous Dispersion of Solid Amorphous 1,4-di(benzoxazol-2-yl)benzene (DBO-200 Dispersion (A))

[0122] A suspension of 175 g of DBO-400 obtained as outlined in (1), 324 g of water and 65 g Green APG 0810 was prepared. Afterwards the suspension was milled for 2 h with a LabStar laboratory mill using yttrium-stabilized zirconium oxide grinding beads (0.3 mm, from Tosoh Ceramic, Japan) and cooling of the milling chamber (12 C. brine). After removal of the grinding beads, a 30% aqueous dispersion of micronized 1,4-di(benzoxazol-2-yl)benzene was obtained.

[0123] Particle Size: [0124] Malvern: Dn50 186 nm (Dn10=126 nm, Dn90=355 nm) [0125] Coulter: Mean value (intensity distribution): 171 nm

[0126] E 1/1: 839

[0127] DSC: onset temperature: 350 C.; heat capacity: 132 J/g.

[0128] Ratio UVB:UVA: 0.49

[0129] X-ray: FIG. 1, line 4

1.4 Preparation of an Aqueous Dispersion of Crystalline 1,4-di(benzoxazol-2-yl)benzene (DBO-200 Dispersion (C))

[0130] After recrystallisation of coarse particles obtained as outlined in (1.2) from o-dichlorobenzene and drying 73.0% of crystalline 1,4-di(benzoxazol-2-yl)benzene was obtained, which was subsequently milled in analogy to the process outlined in (1.3). After removal of the grinding beads a 30% aqueous dispersion of crystalline 1,4-di(benzoxazol-2-yl)benzene was obtained.

[0131] Particle Size: [0132] Coulter: Mean value (intensity distribution): 193 nm

[0133] E 1/1: 719;

[0134] DSC: Onset temperature: 352 C.; heat capacity: 153 J/g.

[0135] Ratio UVB:UVA: 0.35

[0136] X-ray: FIG. 1, line 2

1.5 Preparation of an Aqueous Dispersion of Coarse Solid Amorphous 1,4-di(benzoxazol-2-yl)benzene (DBO-400 Dispersion (A))

[0137] A suspension of 1.8 g of DBO-400 obtained as outlined in (1), 3.51 g of water and 0.69 g of Green APG 0810 was prepared. Afterwards the suspension was mixed at ambient temperature (22 C.) with a magnetic mixture until a homogenous dispersion was obtained. After removal of the magnetic stir bar a 30% aqueous dispersion of micronized 1,4-di(benzoxazol-2-yl)benzene having a mean particle size Dn50 of 380 nm (Malvern) was obtained.

[0138] 2. Material Transfer

[0139] The material transfer has been determined with the sponge test as outlined in the following: [0140] Cut a sponge cloth (Weitawip Claire, from Weita AG: cellulose/cotton fiber mixture, 200 g/m.sup.2, 5 mm thickness) into pieces of 76 mm26 mm [0141] Tare the sponge sample [0142] Apply 400 mg of the respective sample(=cosmetic composition) and distribute homogenously all over the sponge surface of 76 mm26 mm [0143] Weigh the sponge with the applied sample [0144] Tare a microscope slide (glass plate 76 mm26 mm1 mm) [0145] Put the microscope slide (glass plate) on top of the sponge, on which a balance weight of 500 g (height: 6.3 cm, diameter at area of contact: 3.7 cm) is placed for 10 seconds to apply a specific pressure to the sample [0146] Remove cautiously vertically the microscope slide [0147] Weigh the removed microscope slide and determine accordingly the amount of sample transferred to the glass plate [0148] Repeat the test for each composition 10 times to receive an average value (mean value) for each sample.

[0149] 2.1 Material Transfer in Dependence of the Particle Size

[0150] The formulations as outlined in table 1 have been prepared according to standard methods in the art. Afterward the material transfer was assessed as outlined above.

TABLE-US-00001 TABLE 1 Results of the material transfer (I) INCI Ref-1 Inv-1 Inv-2 Wt.-% Potassium Cetyl Phosphate 1.50 1.50 1.50 Cetyl alcohol 3.00 3.00 3.00 Cetearyl alcohol 1.00 1.00 1.00 Caprylic/Capric triglyceride 8.00 8.00 8.00 Aqua Ad 100 Ad 100 Ad 100 Glycerin 3.00 3.00 3.00 Xanthan Gum 0.30 0.30 0.30 Preservative 1.00 1.00 1.00 Octocrylene 8.00 8.00 8.00 DBO 400 nm, Aqua, Decyl Glucoside 2.4* (30% active) (DBO-400 dispersion (A)) DBO 200 nm, Aqua, Decyl Glucoside 2.4* (30% active) (DBO-200 dispersion (A)) Transfer of cream 1.7% 1.3% 0.8% *Based on active

[0151] As can be retrieved from table 1, the addition of the nano-sized organic UV-filter according to the present invention significantly reduced the amount of cream transferred to the glass surface compared to the reference rendering the glass surfaces less smeary compared to the references.

[0152] 2.2 Material Transfer in Dependence of the Particle Size and the Liquid UV-Filter Oil

[0153] The formulations as outlined in table 2 have been prepared according to standard methods in the art. Afterward the material transfer was assessed as outlined above.

TABLE-US-00002 TABLE 2 Results of the material transfer (II) INCI Inv-3 Inv-4 Inv-5 Inv-6 Inv-7 Inv-8 Inv-9 Inv-10 Wt.-% Potassium Cetyl Phosphate 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Cetyl alcohol 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Cetearyl alcohol 1.0 1.0 1.0 1.0 1.00 1.0 1.00 1.0 Caprylic/Capric triglyceride 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 Aqua Ad 100 Glycerin 3.0 3.0 3.0 3.00 3.0 3.0 3.0 3.0 Xanthan Gum 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Preservative 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Homosalate 10.0 10.0 Ethylhexyl salicylate 5.0 5.0 Polysilicone-15 3.0 3.0 Octyl methoxycinnamate 5.0 5.0 DBO-200 dispersion (A) 2.4* 2.4* 2.4* 2.4* DBO-400 (A) 2.4* 2.4* 2.4* 2.4* % Transfer 0.49 3.11 0.40 2.73 0.78 3.76 0.66 2.59 *Based on active

[0154] As can be retrieved from table 2, the addition of the nano-sized 1,4-di(benzoxazol-2-yl)benzene having a particle size of less than 300 nm exhibited an even more pronounced reduction of the amount of the oils transferred to the glass surface compared to the particles having a particle size of >300 nm rendering the glass surfaces even less smeary. Furthermore, the use of the UV-filter oils octylmethoxycinnamate, ethylhexylsalicylate and homosalate resulted in the best results.

[0155] 2.3 Material Transfer in Dependence of Emulsion Type

[0156] The formulations as outlined in table 3 have been prepared according to standard methods in the art. Afterward the material transfer was assessed as outlined above.

TABLE-US-00003 TABLE 3 Results of the material transfer (III) Inv-11 Inv-12 Inv-13 Inv-14 INCI O/W W/O O/W W/O Wt.-% Potassium Cetyl 1.5 Phosphate Polyglyceryl-2- 5.0 5.0 5.0 dipolyhydroxystearate Cetyl alcohol 3.0 Cetearyl alcohol 1.0 Microcristalline wax 2.0 2.0 2.0 Caprylic/Capric 15 15 15 triglyceride Ethylhexyl 5.0 5.0 salicylate Octocrylene 8.0 8.0 Aqua Ad 100 Glycerin 3.0 3.0 3.0 3.0 Xanthan Gum 0.3 Magnesium sulfate 1.0 1.0 1.0 heptahydrate preservative 1.0 0.5 0.5 0.5 DBO-200 dispersion 2.4* 2.4* 2.4* 2.4* (A) Transfer [%] 0.4 1.26 0.8 1.73 *Based on active

[0157] As can be retrieved from the table, the addition of the nano-sized 1,4-di(benzoxazol-2-yl)benzene according to the present invention significantly reduced the amount of the cream transferred to the glass surface compared to the references rendering the glass surfaces less smeary compared to the references. Additionally, the transfer is significantly lower in the O/W formulations than in the respective W/O formulations.

[0158] 3. UV-Performance of the Solid Amorphous Versus Crystalline Form

[0159] The formulations as outlined in table 4 have been prepared according to standard methods in the art. Afterward the in vitro SPF was assessed directly after manufacturing (t0) and after 1-month storage at RT (t1). The in vitro SPF test was performed on PMMA plates (WW5 from Schnberg, 5 cm5 cm, roughness of 5 m): 32.5 mg of the respective formulation (i.e. 1.3 mg/cm.sup.2) were applied homogenously onto the PMMA plates and dried for 15 minutes.

[0160] The in vitro SPF was determined using a Labsphere 2000 UV Transmittance Analyzer: each PMMA plate was measured 9 times at different points on the plate resulting in 27 data points. The result is calculated as the average of these 27 data points.

TABLE-US-00004 TABLE 4 in vitro SPF Ingredient Wt.-% Wt.-% Potassium Cetyl Phosphate 1.8 1.8 Glyceryl Stearate 2.0 2.0 Stearyl Alcohol 2.5 2.5 Isopropyl Myristate 2.0 2.0 C12-15 Alkyl Benzoate 5.0 5.0 Caprylic/Capric Triglyceride 5.0 5.0 Xanthan Gum 0.4 0.4 Aqua Ad 100 Ad 100 Preservative 1.0 1.0 amorphous DBO (30% active) 3* (DBO-200 dispersion (A)) crystalline DBO (30% active) 3* (DBO-200 dispersion (C)) In vitro SPF @ t0 9.1 6.5 In vitro SPF @ t1 8.7 2.9 Critical wavelength 379 382 *based on the active (i.e. 10 wt.-% of the respective dispersion)

[0161] As can be retrieved from table 4 the use of solid amorphous DBO results in a significantly higher SPF compared to the respective crystalline form. Furthermore, such formulations are more storage stable as reflected by an unchanged in vitro SPF after 1-month storage @ RT for the solid amorphous form compared to a significantly reduced SPF after 1-month storage @ RT for of the respective crystalline form.