TOPICAL COMPOSITION COMPRISING AN INORGANIC UV-FILTER

Abstract

The present invention relates to isopropylparabene free topical compositions comprising a specific polyester and at least one inorganic UV-filter. Furthermore, the present invention relates to the use of the combination of such polyesters and inorganic UV-filters to reduce the stickiness of compositions comprising either the polyester or the inorganic UV-filter.

Claims

1. An isopropylparabene free topical composition comprising an inorganic UV-filter wherein the composition further comprises a polyester comprising (i) between 20 to 50 wt.-%, based on the total weight of the polyester, of 2-(4-C.sub.1-8 alkoxybenzylidene)malonate units and (ii) between 50 to 80 wt.-%, based on the total weight of the polyester, C36 dimer fatty units, and with the proviso that the polyester has a hydroxyl value selected in the range of 0 to 120 mg KOH/g, a number average molecular weight (Mn) selected in the range of 1000 to 8000 g/mol and a viscosity of less than 250 Pa.Math.s (25° C.).

2. The topical composition according to claim 1, wherein the polyester is a polyester obtainable by polycondensation of a C.sub.1-8dialkyl 2-(4-C.sub.1-8 alkoxybenzylidene)malonate and C36 fatty diol.

3. The topical composition according to claim 2, wherein the C.sub.1-8dialkyl 2-(4-C.sub.1-8alkoxybenzylidene)malonate is selected from the group consisting of di(m)ethyl 2-(4-(m)ethoxybenzylidene)malonate.

4. The topical composition according to claim 1, wherein the polyester is obtained by transesterification of a C.sub.1-8dialkyl 2-(4-C.sub.1-8 alkoxybenzylidene)malonate and C36 fatty diol in a mol ratio selected in the range of 1:1.5 to 1.5:1, preferably in the range of 1:1.25 to 1:1, most preferably in the range of 1:1.2 to 1:1.1.

5. The topical composition according to claim 1, wherein the inorganic UV-filter is selected from the group consisting of optionally surface treated titanium dioxide and optionally surface treated zinc oxide as well as mixtures thereof.

6. The topical composition according to claim 5, wherein the titanium dioxide and the zinc oxide are surface treated.

7. The topical composition according to claim 6, wherein the titanium dioxide is double coated titanium dioxide coated with an inner silica and an outer dimethicone coating and the zinc oxide is a zinc oxide coated with triethoxycaprylylsilane.

8. The topical composition according to claim 1, wherein the amount (total) of the inorganic UV-filter in the topical composition is selected in the range from 0.1 to 50 wt.-%, more preferably from 1 to 30 wt.-%, most preferably from 2.5 to 25 wt.-%, based on the total weight of the topical composition.

9. The topical composition according to claim 1, wherein the amount of the polyester in the topical compositions is selected in the range from 0.1 to 15 wt.-%, preferably in the range from 0.5 to 10 wt.-%, most preferably in the range from 1 to 7 wt.-%, based on the total weight of the topical composition.

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

11. 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.

12. 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, preferably in the presence of a cetyl phosphate.

13. Use of an inorganic UV-filter to reduce the transfer of a topical composition comprising a polyester according to claim 1 to a surface and/or to reduce the stickiness of topical composition comprising a polyester according to anyone of the preceding claims.

14. Method to reduce the transfer of a topical composition comprising a polyester according to claim 1 to a surface, said method encompassing the addition of an inorganic UV-filter to said topical composition.

15. Method to reduce the stickiness of a topical composition comprising a polyester or an inorganic UV-filter according to claim 1, said method encompassing the combined use of said polyester and said inorganic UV-filter addition in the topical composition.

Description

EXPERIMENTAL PART

Example 1: Preparation of the Polyester

[0108] Dimethyl 2-(4-methoxybenzylidene)malonate (Hostavin PR-25, Clariant) and C36 fatty diol (Radianol 1990, Oleon) in a molar ratio of 1:1.09 were charged in a reactor (250 g batch). Afterwards a catalytic amount of tetrabutyl titanate (Lehmann & Voss) was added (approx. 0.1 g per 100 g reaction mixture). Then the reaction mixture was heated to 120° C. Once oligomers were formed, vacuum was applied to remove methanol (MeOH) and further built up the polymer. During this time, samples were taken, and the reaction was stopped at an OHV of 34-38 mg KOH/g. Then, the reaction mixture was cooled, and the obtained polyester was discharged obtaining a polyester having an OHV of 38.2 mg KOH/g, a Mn of 2350 g/mol, a polydispersity of 1.7 and a viscosity of 44.8 Pa S at 25° C. (determined according to ISO 3219).

Example 2: Application Tests

[0109] The formulations (O/W emulsions) as outlined in table 1 have been prepared according to standard methods in the art.

[0110] Transfer onto Surfaces

[0111] Then the transfer resistance has been tested with the sponge test as outlined below: [0112] Cut a sponge cloth (Weitawip Claire from Weita AG (Art. No 279051), cellulose/cotton mixture, 200 g/m.sup.2) into pieces of 76 mm×26 mm [0113] Tare the sponge sample [0114] Apply 350 mg cream and distribute homogenously all over the sponge surface of 76 mm×26 mm [0115] Weigh the sponge with the applied sample [0116] Tare microscope slide (glass plate 76 mm×26 mm) [0117] Put a microscope slide (glass plate) on top of the sponge and charge it with a 500 g weight for 10 seconds [0118] Weigh the amount of cream transferred to the glass plate [0119] Repeat the test for each formulation 10 times to receive an average value (mean value) for each formulation

TABLE-US-00001 TABLE 1 O/W emulsion Ref-1 Inv-1 Inv-2 INCI wt.-% Potassium cetyl phosphate 1.50 1.50 1.50 Cetyl Alcohol 3.00 3.00 3.00 C12-15 alkyl benzoate 8.00 8.00 8.00 Dicaprylyl Carbonate 8.00 8.00 8.00 Phenoxyethanol, 1.00 1.00 1.00 Ethylhexylglycerin Polyester of example 1 5.00 5.00 5.00 Titanium dioxide coated with — 5.00 silica and dimethicone.sup.1 Zinc oxide coated with — 5.00 triethoxycaprylylsilane.sup.2 Xanthan gum 0.30 0.30 0.30 Disodium EDTA 0.10 0.10 0.10 Aqua Ad 100 Ad 100 Ad 100 Glycerin 3.00 3.00 3.00 Transfer to glass plate 28.1 12.7 12.5 mean value [mg] .sup.1PARSOL ® TX (DSM nutritional Products Ltd) .sup.2SUNZnO-NAS (Sunjin)

[0120] As can be retrieved from table 1, an emulsion comprising the combination of an inorganic UV-filter and a polyester according to the present invention exhibited a significantly reduced amount of cream transferred to the glass surface compared to an emulsion comprising only the polyester.

[0121] Stickiness

[0122] Afterwards the stickiness of the formulation was tested by measuring the sand adherence: as outlined below: [0123] The cream was applied on Schönberg plates (2 mg/cm.sup.2) [0124] The plates were dried for 15 minutes at 40° C. to form a film, [0125] The plate with the dried film were weighted (control plate), [0126] Sand was put into a petri dish, [0127] The plate was placed with the dried film side into the sand and a weight (500 g) was put onto the plate, [0128] After 5 minutes the plate was taken out of the sand and weighted (sample weight) [0129] The amount of sand sticking to the plate was calculated (sample weight−control weight)

[0130] The results are presented below in table 2 (mean value from 6 plates).

TABLE-US-00002 TABLE 2 Ref-2 Ref-3 Inv-3 Inv-4 INCI wt.-% Potassium cetyl phosphate 1.50 1.50 1.50 1.50 Cetyl Alcohol 3.00 3.00 3.00 3.00 C12-15 alkyl benzoate 8.00 8.00 8.00 8.00 Dicaprylyl Carbonate 8.00 8.00 8.00 8.00 Phenoxyethanol, 1.00 1.00 1.00 1.00 Ethylhexylglycerin Polyester of example 1 — 5.00 — 5.00 Titanium dioxide coated with — — 5.00 5.00 silica and dimethicone.sup.1 Xanthan gum 0.30 0.30 0.30 0.30 Disodium EDTA 0.10 0.10 0.10 0.10 Aqua Ad 100 Ad 100 Ad 100 Ad 100 Glycerin 3.00 3.00 3.00 3.00 Sand sticking to plate [mg] 0.52 0.83 0.58 0.52 .sup.1PARSOL ® TX (DSM nutritional Products Ltd) .sup.2 SUNZnO-NAS (Sunjin)

[0131] As can be retrieved from the results presented in table 2, the addition of either the inorganic UV-filter or the polyester according to the present invention leads to an increase in stickiness, while the combined use resulted in a synergistically reduced stickiness (i.e. sand adherence), equivalent to the stickiness of the formulation without any UV-filter.