Surface-reacted calcium carbonate for modifying the biomechanical properties of the skin

Abstract

The present invention refers to the use of a surface-reacted calcium carbonate in a cosmetic and/or skin care composition as an agent for modifying the biomechanical properties of the skin.

Claims

1. A method for modifying the biomechanical properties of the skin comprising applying to the skin a cosmetic and/or skin care composition comprising a surface-reacted calcium carbonate, wherein the surface-reacted calcium carbonate has a volume median particle size d.sub.50 from 0.1 to 90 μm, the surface-reacted calcium carbonate is a reaction product of natural ground calcium carbonate or precipitated calcium carbonate with carbon dioxide and one or more H.sub.3O.sup.+ ion donors, wherein the carbon dioxide is formed in situ by the H.sub.3O.sup.+ ion donors treatment and/or is supplied from an external source, the amount of the surface-reacted calcium carbonate in the cosmetic and/or skin care composition is from 0.1 to 5 wt-% based on the total weight of the cosmetic and/or skin care composition, and the method results in a modification of one or more of firmness of the skin, elasticity of the skin, or plasticity of the skin.

2. The method of claim 1, wherein the surface-reacted calcium carbonate has a volume median particle size d.sub.50 from 0.5 to 50 μm.

3. The method of claim 1, wherein the surface-reacted calcium carbonate has a specific surface area of from 15 m.sup.2/g to 200 m.sup.2/g, measured using nitrogen and the BET method.

4. The method according to claim 1, wherein the natural ground calcium carbonate is selected from the group consisting of marble, chalk, limestone, and mixtures thereof, or the precipitated calcium carbonate is selected from the group consisting of precipitated calcium carbonates having an aragonitic, vateritic or calcitic crystal form, and mixtures thereof.

5. The method according to claim 1, wherein the at least one H.sub.3O.sup.+ ion donor is selected from the group consisting of hydrochloric acid, sulphuric acid, sulphurous acid, phosphoric acid, citric acid, oxalic acid, an acidic salt, acetic acid, formic acid, and mixtures thereof.

6. The method according to claim 1, wherein the modification of the biomechanical properties of the skin refers to the skin firmness.

7. The method according to claim 1, wherein the skin refers to the skin of the arms, the skin of the hands, the skin of the legs, the skin of the feet, the skin of the neck, the skin of the chest, and/or the skin of the face.

8. The method according to claim 1, wherein the cosmetic and/or skin care composition has a pH value of ≤8.5.

9. The method according to claim 1, wherein the surface-reacted calcium carbonate is present in the cosmetic and/or skin care composition in an amount from 0.1 to 50 wt.-%, based on the total weight of the composition.

10. The method according to claim 1, wherein the cosmetic and/or skin care composition further comprises water and/or at least one oil.

11. The method according to claim 1, wherein the cosmetic and/or skin care composition comprises at least one active agent being adsorbed onto and/or absorbed into the surface of the surface-reacted calcium carbonate.

12. The method according to claim 11, wherein the at least one active agent is selected from pharmaceutically active agents, biologically active agents, vitamins, disinfecting agents, preservatives, flavouring agents, surfactants, oils, fragrances, essential oils, and mixtures thereof.

13. The method according to claim 1, wherein the composition further comprises at least one additive selected from the group consisting of bleaching agents, thickeners, stabilizers, chelating agents, preserving agents, wetting agents, emulsifiers, emollients, fragrances, colorants, skin tanning compounds, antioxidants, minerals, pigments, UV-A and/or UV-B filter, and mixtures thereof.

14. The method according to claim 1, wherein the cosmetic and/or skin care composition is selected from an eye make-up product, a facial make-up product, a lip care product, a hand care product, a skin care product, or a combination product thereof.

15. The method according to claim 1, wherein the surface-reacted calcium carbonate does not lead to negative side-effects or does not lead to skin irritation, after application on the skin.

16. The method according to claim 1, wherein the at least one H.sub.3O.sup.+ ion donor is selected from the group consisting of hydrochloric acid, sulphuric acid, sulphurous acid, phosphoric acid, oxalic acid, H.sub.2PO.sub.4.sup.−, being at least partially neutralised by a cation selected from Li.sup.+, Na.sup.+ and/or K.sup.+, HPO.sub.4.sup.2−, being at least partially neutralised by a cation selected from Li.sup.+, Na.sup.+, K.sup.+, Mg.sup.2+, and/or Ca.sup.2+, and mixtures thereof.

17. The method according to claim 1, wherein the modification of the biomechanical properties of the skin refers to an increased skin firmness.

18. The method according to claim 1, wherein the skin refers to the skin of the face.

19. The method according to claim 1, wherein the cosmetic and/or skin care composition has a pH value of ≤8.0.

20. The method according to claim 1, wherein the surface-reacted calcium carbonate is present in the cosmetic and/or skin care composition in an amount from 0.5 to 20 wt.-%, based on the total weight of the composition.

21. The method according to claim 1, wherein the cosmetic and/or skin care composition further comprises water, and/or at least one oil selected from the group consisting of vegetable oils and esters thereof, alkanecoconutester, plant extracts, animal fats, siloxanes, silicones, fatty acids and esters thereof, petrolatum, glycerides and pegylated derivatives thereof.

Description

EXAMPLES

(1) 1. Measurement Methods

(2) In the following, measurement methods implemented in the examples are described.

(3) Particle Size Distribution

(4) Volume determined median particle size d.sub.50(vol) and the volume determined top cut particle size d.sub.98(vol) was evaluated using a Malvern Mastersizer 2000 Laser Diffraction System (Malvern Instruments Plc., Great Britain). The d.sub.50(vol) or d.sub.98(vol) value indicates a diameter value such that 50% or 98% by volume, respectively, of the particles have a diameter of less than this value. The raw data obtained by the measurement was analyzed using the Mie theory, with a particle refractive index of 1.57 and an absorption index of 0.005. The methods and instruments are known to the skilled person and are commonly used to determine particle size distributions of fillers and pigments.

(5) The weight determined median particle size d.sub.50(wt) was measured by the sedimentation method, which is an analysis of sedimentation behaviour in a gravimetric field. The measurement was made with a Sedigraph™ 5120 of Micromeritics Instrument Corporation, USA. The method and the instrument are known to the skilled person and are commonly used to determine particle size distributions of fillers and pigments. The measurement was carried out in an aqueous solution of 0.1 wt.-% Na.sub.4P.sub.2O.sub.7. The samples were dispersed using a high speed stirrer and supersonicated.

(6) Specific Surface Area (SSA)

(7) The specific surface area was measured via the BET method according to ISO 9277 using nitrogen, following conditioning of the sample by heating at 250° C. for a period of 30 minutes. Prior to such measurements, the sample was filtered within a Buchner funnel, rinsed with deionised water and dried overnight at 90 to 100° C. in an oven. Subsequently, the dry cake was ground thoroughly in a mortar and the resulting powder was placed in a moisture balance at 130° C. until a constant weight was reached.

(8) Intra-Particle Intruded Specific Pore Volume (in Cm.sup.3/g)

(9) The specific pore volume was measured using a mercury intrusion porosimetry measurement using a Micromeritics Autopore V 9620 mercury porosimeter having a maximum applied pressure of mercury 414 MPa (60 000 psi), equivalent to a Laplace throat diameter of 0.004 μm (˜nm). The equilibration time used at each pressure step was 20 seconds. The sample material was sealed in a 5 cm.sup.3 chamber powder penetrometer for analysis. The data were corrected for mercury compression, penetrometer expansion and sample material compression using the software Pore-Comp (Gane, P. A. C., Kettle, J. P., Matthews, G. P. and Ridgway, C. J., “Void Space Structure of Compressible Polymer Spheres and Consolidated Calcium Carbonate Paper-Coating Formulations”, Industrial and Engineering Chemistry Research, 35(5), 1996, p 1753-1764).

(10) The total pore volume seen in the cumulative intrusion data can be separated into two regions with the intrusion data from 214 μm down to about 1-4 μm showing the coarse packing of the sample between any agglomerate structures contributing strongly. Below these diameters lies the fine inter-particle packing of the particles themselves. If they also have intra-particle pores, then this region appears bi-modal, and by taking the specific pore volume intruded by mercury into pores finer than the modal turning point, i.e. finer than the bi-modal point of inflection, the specific intra-particle pore volume is defined. The sum of these three regions gives the total overall pore volume of the powder, but depends strongly on the original sample compaction/settling of the powder at the coarse pore end of the distribution.

(11) By taking the first derivative of the cumulative intrusion curve the pore size distributions based on equivalent Laplace diameter, inevitably including pore-shielding, are revealed. The differential curves clearly show the coarse agglomerate pore structure region, the inter-particle pore region and the intra-particle pore region, if present. Knowing the intra-particle pore diameter range it is possible to subtract the remainder inter-particle and inter-agglomerate pore volume from the total pore volume to deliver the desired pore volume of the internal pores alone in terms of the pore volume per unit mass (specific pore volume). The same principle of subtraction, of course, applies for isolating any of the other pore size regions of interest.

(12) 2. Pigment Materials

(13) GCC1

(14) GCC 1 is high purity natural calcium carbonate obtained from limestone, sold by Omya, and shows the characteristics listed in Table 1 below.

(15) SRCC 1

(16) SRCC 1 has a d.sub.50=1.6 μm, d.sub.98=10.0 μm, a SSA=31.4 m.sup.2/g and an intra-particle intruded specific pore volume of 0.837 cm.sup.3/g (for the pore diameter range of 0.004 to 0.59 μm).

(17) SRCC 1 was obtained by preparing 7 liters of an aqueous suspension of ground calcium carbonate in a mixing vessel by adjusting the solids content of a ground marble calcium carbonate from Omya Madencilik A. S., Turkey, having a mass based median particle size of 0.4 μm, as determined by sedimentation, such that a solids content of 15 wt.-%, based on the total weight of the aqueous suspension, is obtained.

(18) Whilst mixing the slurry, 290 g phosphoric acid was added in form of an aqueous solution containing 10 wt.-% phosphoric acid to said suspension over a period of 100 minutes at a temperature of 70° C. After the addition of the acid, the slurry was stirred for additional 5 minutes, before removing it from the vessel, filtering the product for removing excess water and then further drying in an oven.

(19) TABLE-US-00001 TABLE 1 Properties of used pigment materials Oil d.sub.50 d.sub.98 SSA Absorption R(y) Products (μm) (μm) (m.sup.2/g) (g/100 g) (%) SRCC 1 1.6 10.0 31.4 44 96.4 GCC 1 0.85 5.0 9.7 18 91.7

(20) 3. Other Materials—Tradenames/Suppliers/INCI Names of Ingredients

(21) TABLE-US-00002 TABLE 2 Ingredients for a cosmetic and/or skin care composition Ingredients INCI Nomenclature Suppliers A) Lanette O Cetearyl Alcohol 8) Imwitor 372P Glyceryl Stearate Citrate 1) Almond Oil Prunus Amygdalus Dulcis 3) (Sweet Almond) Oil Apricot Oil Prunus Armeniaca (Apricot) 3) Kernel Oil KCC SF1000N-100 cSt Polydimethylsiloxane 2) KCC 4130P Stearyl Dimethicone 2) Coconut Oil Cocos nucifera Oil 7) B) Water dem. Aqua (water) 1,2-Propanediol Propylene Glycol Glycerin Glycerin Xanthan Gum Xanthan Gum 5) Potassium Sorbate Potassium Sorbate 8) Sodium Chloride Sodium Chloride D) Phenochem NIB Methylparaben (and) 6) Ethylparaben (and) Butylparaben (and) Propylparaben (and) Phenoxyethanol 1) Sasol GmbH, Germany 2) KCC Silicone Corporation, Korea 3) Hänseler AG, Switzerland 4) Sigma Aldrich, Switzerland 5) Omya Hamburg GmbH, Germany 6) SLI Chemicals GmbH, Germany 7) Georges Walther AG, Switzerland 8) Cognis GmbH, Germany

(22) 4. Biomechanical Properties—Test Results

(23) TABLE-US-00003 TABLE 3 Skin care and/or cosmetic compositions Composition No. 1 2 Ingredients INCI Nomenclature % w/w % w/w A) Lanette O Cetearyl Alcohol 2.00 2.00 Imwitor 372P Glyceryl Stearate Citrate 5.00 5.00 Almond Oil Prunus Amygdalus Dulcis 2.00 2.00 (Sweet Almond) Oil Apricot Oil Prunus Armeniaca (Apricot) 3.00 3.00 Kernel Oil KCC SF1000N-100 cSt Polydimethylsiloxane 2.00 2.00 KCC 4130P Stearyl Dimethicone 2.00 2.00 Coconut Oil Cocos nucifera Oil 3.00 3.00 B) Water dem. Aqua (water) add. 100 add. 100 1,2-Propanediol Propylene Glycol 4.00 4.00 Glycerin Glycerin 3.00 3.00 Xanthan Gum Xanthan Gum 0.20 0.20 Potassium Sorbate Potassium Sorbate 0.20 0.20 Sodium Chloride Sodium Chloride 0.90 0.80 C) GCC1 5 5 SRCC1 D) Phenochem NIB Methylparaben (and) 1.00 1.00 Ethylparaben (and) Butylparaben (and) Propylparaben (and) Phenoxyethanol 100.00 100.00

(24) The cosmetic compositions were prepared as follows: Heat phase A & B separately at 80° C. Add phase B to phase A while stirring (Heidolph, Faust, 300 rpm) Cool down at room temperature Add part C & D and homogenize (Ultra Turrax T25-D, IKA, 24 000 rpm) Adjust the pH at 6.0 using lactic acid (10%-solution)

(25) 4.1 Measurement of Biomechanical Properties of the Skin

(26) Firmness measurements were carried out with a MPA 580 Cutometer® (Courage & Khazaka). The measurement is based on an in vivo non-invasive method to evaluate skin rheological properties: measures of biological extensibility and elasticity variations. The technique consists on the suction of the skin in the orifice of a probe by a constant vacuum pressure and for a constant duration. The depth of penetration of the skin into the probe is measured, without friction and mechanical effects, by using two optical prisms located at the opening of this probe. Cutaneous skin elasticity was performed with a 2 mm probe with a 450 mbar constant pressure and one cycle of measurement. Suction and relaxation times are 3 seconds each. Each measurement is an average of two acquisitions. The cutaneous firmness parameter Uf was studied. FIG. 1 shows a skin deformation curve obtained with a Cutometer® and the measured parameters.

(27) Table 4 shows test results for a comparative skin care and/or cosmetic composition comprising GCC 1.

(28) TABLE-US-00004 TABLE 4 Comparative skin care and/or cosmetic composition comprising GCC 1 % of subjects Param- ΔΔ Dx-DO % of with an eters Kinetic (mean ± SEM) efficacy improvement Firmness R0 (Uf) Δ D28 −0.083 ± +22% 90 0.014

(29) It can be gathered from the data shown in Table 4 that after 28 days of once daily use, the composition comprising GCC 1 induced a certain improvement of biomechanical properties of the skin, characterized by: a decrease in firmness parameter (R0 (Uf)) of 22% on average.

(30) TABLE-US-00005 TABLE 5 Inventive skin care and/or cosmetic composition comprising SRCC 1 % of subjects Param- ΔΔ Dx-DO % of with an eters Kinetic (mean ± SEM) efficacy improvement Firmness R0 (Uf) Δ D28 −0.103 ± +27% 90 0.020

(31) It can be gathered from the data shown in Table 5 that after 28 days of once daily use, the composition comprising SRCC 1 induces an improvement of biomechanical properties of the skin. The improved is characterized by a significant decrease in firmness parameter (R0 (Uf)) of 27% on average, and thus in an increased skin firmness. Furthermore, a firm skin was observed in 90% of the subjects.

(32) By comparing the data shown in Table 4 and Table 5, it can be seen that the inventive composition comprising a surface-reacted calcium carbonate provides better results for the modification of skin firmness when compared to a composition comprising a ground calcium carbonate.

(33) 4.2 Sensory Evaluation of the Skin Care and/or Cosmetic Composition

(34) Composition 1 comprising GCC 1 and composition 2 comprising SRCC 1 were tested by subjects concerning unpleasant skin sensations such as skin irritation. The results of the study were evaluated after a time period of 28 days.

(35) During the test study with composition 1 comprising GCC 1, 5% of the subjects reported cutaneous/ocular irritation sensations.

(36) During the test study, none of the subjects complained about irritation sensations after or during the application of composition 2 comprising SRCC1.

(37) Thus, the cosmetic and/or skin care composition comprising SRCC 1 is not irritant, and therefore in any case, less irritant to the skin than the cosmetic and/or skin care composition comprising GCC 1.