Personal care composition

Abstract

An aqueous shear-thinning personal care composition comprises: (a) at least 3 wt % of a sulfonate compound of general formula (I): where R.sup.1 represents a C.sub.8-22 alkyl group alkyl group; R.sup.2 represents a C.sub.1-4 alkyl group; each of R.sup.3, R.sup.4 and R.sup.5 independently represents a hydrogen atom or a C.sub.1-4 alkyl group; and M.sup.+ represents a sodium or potassium cation; (b) at least 3 wt % of an amphoteric or zwitterionic surfactant; (c) at least 10 wt % of water; and (d) at least 0.5 wt % of an additional component in the form of particles or droplets suspended in the composition. The composition is stable in an aqueous environment and can be formulated with a wide range of additional components.

Claims

1. An aqueous, shear thinning personal care composition comprising: (a) at least 3 wt % of a sulfonate compound of general formula: ##STR00009## where R.sub.1 represents a C.sub.8-22 alkyl group; R.sub.2 represents a C.sub.1-4 alkyl group; and each of R.sub.3, R.sub.4 and R.sub.5 independently represents a hydrogen atom or a C.sub.1-4 alkyl group; and M.sup.+ represents a cation; (b) at least 3 wt % of an amphoteric or zwitterionic surfactant; (c) at least 10 wt % of water; (d) from about 0.1% to about 50% wt % of an additional component in the form of solid or non-solid water-insoluble particles or droplets suspended in the composition; (e) an electrolyte present in an amount from 2 wt % to 25 wt %; and wherein said composition is capable of maintaining said solid or non-solid water-insoluble particles or droplets in suspension without sedimentation or separation over a time period of at least one month, and wherein the composition does not comprise an additional structurant.

2. The composition as claimed in claim 1 wherein R.sub.2 represents a methyl group.

3. The composition as claimed in claim 1 wherein each of R.sub.3, R.sub.4 and R.sub.5 represents a hydrogen atom.

4. The composition as claimed in claim 1 wherein component (a) is present in an amount of up to 30 wt %.

5. The composition as claimed in claim 1 wherein component (b) is present in an amount of up to 30 wt %.

6. The composition as claimed in claim 1 wherein component (c) is present in an amount of from 20% to 95% by total composition weight.

7. The composition as claimed in claim 1 wherein component (d) is present in an amount from at least 0.5 wt %.

8. The composition as claimed in claim 1, wherein said additional component (d) is a benefit agent.

9. The composition as claimed in claim 1, wherein the composition further includes a benefit agent.

10. The composition as claimed in claim 1, formulated as a product selected from the following: a bath or shower gel; a hand washing composition; a facial washing composition; a pre-, during- or post-shaving product; a skin moisturizer; a hair gel; a medicinal skin treatment product; a shampoo; a hair conditioner; a dental product.

11. The composition as claimed in claim 1, wherein said electrolyte is present in an amount up to 15 wt %.

12. The composition as claimed in claim 1, wherein said electrolyte is present in an amount up to 10 wt %.

13. A personal care composition comprising: a) a viscous, shear-thinning component consisting essentially of water and (i) at least 3 wt % of a sulfonate compound of general formula: ##STR00010## where R.sub.1 represents a C.sub.8-22 alkyl group; R.sub.2 represents a C.sub.1-4 alkyl group; and each of R.sub.3, R.sub.4 and R.sub.5 independently represents a hydrogen atom or a C.sub.1-4 alkyl group; and M.sup.+ represents a cation; ii) at least 3 wt % of an amphoteric and/or zwitterionic surfactant component; iii) from 2 wt % to 25 wt % of an electrolyte component; and iv) from about 0.1 wt % to about 50 wt % of an additional component in the form of solid or non-solid water-insoluble particles or droplets suspended in the composition; wherein said composition maintains said solid or non-solid water-insoluble particles or droplets in suspension without sedimentation or separation over a time period of at least one month, and wherein the composition does not comprise an additional structurant.

14. The composition as claimed in claim 13 wherein R.sub.2 represents a methyl group.

15. The composition as claimed in claim 14 wherein each of R.sub.3, R.sub.4 and R.sub.5 represents a hydrogen atom.

16. The composition as claimed in claim 13, wherein said additional component comprises a benefit agent.

17. The composition as claimed in claim 13, wherein the composition further comprises a benefit agent.

18. The composition as claimed in claim 13, formulated as a product selected from the following: a bath or shower gel; a hand washing composition; a facial washing composition; a pre-, during- or post-shaving product; a skin moisturizer; a hair gel; a medicinal skin treatment product; a shampoo; a hair conditioner; a dental product.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a plot showing the amount of sodium cocoylmethylisethionate (SCMI) present in aqueous solutions having various pH values following incubation at 48.9 C. at various intervals over a 30 day period of time.

(2) FIG. 2 is a plot showing the pH stability of sodium cocoylmethylisethionate (SCMI) present in aqueous solutions having various pH values following incubation at 48.9 C. at various intervals over a 30 day period of time.

(3) FIG. 3 is a plot showing skin irritancy properties of a number of compounds, including two sulfate surfactants; SLS and SLES (known to have significant irritancy), distilled water, SCI (known to have low irritancy) and SCMI, as described in Example 3.

EXAMPLE 1

(4) In a preliminary test the stability of SCMI in 10 wt % aqueous solutions adjusted to have initial pH values respectively of 4.5, 5.5, 6.5, 7.5, 8.5 and 9.5, each held at 48.9 C. for an extended period of days, were tested for the amount of SCMI present over the test period.

(5) The pH values were read using a standard electrode pH meter (Fisher Accument XL-25). The electrode was place in the composition (no further dilution) and the pH recorded.

(6) The results are shown in FIG. 1. It can be seen that the percentage of SCMI does not change from Day 0 to Day 30, at any of these pH values.

EXAMPLE 2

(7) In a preliminary test 10 wt % solutions of SCMI, adjusted to have initial pH values respectively of 4.5, 5.5, 6.5, 7.5, 8.5 and 9.5, each held at 48.9 C. for an extended period of days, were tested for their pH stability over the extended period. The pH testing was as described above.

(8) The results are shown in FIG. 2. It can be seen that the pH values were substantially unchanged from Day 0 to Day 30 at all these pH values, except for a small pH reduction in the first few days, for the sample held at the highest pH value, 9.5.

EXAMPLE 3

(9) In a preliminary test based on the Zein protocol the skin irritancy properties of a number of compounds were tested, including two sulfate surfactants SLS and SLES (known to have significant irritancy), distilled water, SCI (known to have low irritancy) and SCMI. The results are shown in FIG. 3. SCMI and SLMI were shown to have low irritancy, similar to that shown by SCI; and significantly lower than the sulfates.

(10) The Zein protocol is an in-vitro test to measure skin irritancy of formulations. The method makes use of the correlation between binding ability of surfactants to proteins and the damage the surfactant causes to the skin. The de-naturation of epidermal protein is a key mechanism in the development of observable damage to the skin by surfactants. Zein protein, an insoluble protein extracted from corn kernel, is used as a model for epidermal protein and the solubility of the Zein protein in surfactant solutions is believed to be a reliable guide for the skin irritancy caused by the surfactant. The test involves establishing the amount of Zein protein which can be solubilised by surfactant. 5 g of Zein protein may be dispersed in 40 cm.sup.3 of surfactant solution (at 2 wt % concentration). The mixture is shaken for 1 hour at 35 C., and immediately centrifuged to remove any non-solubilised Zein. The amount solubilised is estimated from the solution nitrogen content using micro-Kjeldahl method (making allowance for any nitrogen in the compound tested).

EXAMPLE 4

(11) Simple solubility tests were carried out.

(12) 10 wt % of SCI shaken with deionised water gave a milky white suspension. The solubility limit of SCI in water is quoted as 0.5 wt %.

(13) 10 wt % of SCMI added to deionised water immediately gave a clear solution.

(14) 10 wt % of SCEI added to deionised water immediately gave a clear solution.

EXAMPLE 5

(15) Foaming tests were performed using a capped measuring cylinder which was charged with an aliquot of the stated surfactant leaving room for foam to form. Foam heights in the graduated cylinder were measured at the start and after 10 inversions of the cylinder. The operation was carried out in the same manner for each surfactant.

(16) 100% SLES gave a foam of medium height but which was also open and watery.

(17) 80 wt % SLS/20 wt % CAPB gave a foam which was high but open and watery.

(18) 100% SCMI gave a foam of medium height but which was rich and creamy.

(19) 80% SCMI/20% CAPB gave a foam of medium height but which was rich and creamy.

EXAMPLES 6 TO 14

(20) Formulated compositions containing canola oil as benefit agent were prepared and tested for viscosity and physical stability over a one-month period. The results are set out in the table below.

(21) TABLE-US-00001 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Water 51.6 50.6 49.6 48.6 66.66 49.6 49.6 45.35 42.85 NTRLQUEST E-30 (formerly 1 1 1 1 1 1 OCTAQUEST E-30) Tetrasodium EDTA (40%) 0.25 0.25 FINSOFT C-17 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Cocamidopropyl betaine (30%) 12.5 16.67 12.5 12.5 12.5 12.5 Sodium Lauroamphoacetate 12.5 12.5 12.5 5 7.5 SCMI (85%) 15 15 15 15 6.17 15 SLMI (85%) 15 15 15 Cocamide MEA 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 Canola oil 12 12 12 12 2.5 12 12 12 12 Sodium chloride 3 4 5 6 8 5 5 5 5 50% citric acid solution (to pH 1 1 1 1 1 1 1 1 5-6) NTRLQUEST, OCTAQUEST, FINSOFT are registered trade marks of Innospec Brookfield RVT Viscometer Heleopath T-Bar Spindles @ 25 C. T-Bar Spindle B @ 1 RPM 14,800 18,000 27200 37200 T-Bar Spindle B @ 2.5 RPM 8320 9600 13,760 18400 T-Bar Spindle C @ 1 RPM 17000 60000 56000 77000 77000 T-Bar Spindle C @ 2.5 RPM 20400 28400 28000 37200 36400 Appearance White White White White White White White White White Lotion Lotion Lotion Lotion Lotion Lotion Lotion Lotion Lotion Stability over 1 month test Stable Stable Stable Stable Stable Stable Stable Stable Stable period

(22) The formulations of Examples 15 and 16 were prepared by progressive mixing and blending of the components, in the order given. The pH was adjusted to between 5.2 and 5.8 using citric acid after blending of the preceding components (in the respective tables), but before blending in of the fragrance, dye and preservative.

EXAMPLE 15

(23) The following moisturizing and conditioning shampoo was prepared.

(24) TABLE-US-00002 Ingredients Tradename (Supplier) % w/w Water to 100 Trisodium Natrlquest E30 0.15 Ethylenediamine (Innospec) disuccinate Sodium Chloride 4.00 Guar Activsoft C-17 0.2 Hydroxypropyltrimonium (Innospec) Chloride Disodium Miranol C2M Conc. 7.5 Cocoamphodipropionate (Rhodia) Sodium Methyl Cocoyl Pureact WS Conc. 7.5 Taurate (Innospec) Guar Gum Activsoft S (Innospec) 0.5 Glycerin 1.00 SLMI Pureact SLMI-85 12.5 (Innospec) Cocamide MEA Aminol CM Flakes 3.5 (Innospec) Quaternium 75 Condicare CT (Innospec) 2.00 Dimethicone Dow Corning 200 Fluid 4.00 (Dow Corning) Cocamidopropyl Betaine Mirataine BET C-30 10.00 (Rhodia) Citric Acid (50% soln) pH 5-2-5.8 Preservative trace Fragrance trace Dye(s) trace

(25) The viscosity of the conditioning shampoo of Example 15 was tested under different shear rates, on a viscometer with a T-Bar C Spindle, at 22 C. The results were as follows: 0.5 RPM=160,000 cps 1.0 RPM=90,000 cps 2.5 RPM=42,400 cps

EXAMPLE 16

(26) The following foaming body lotion was prepared.

(27) TABLE-US-00003 Ingredients Tradename (Supplier) % w/w to 100 Water to 100 Trisodium Natrlquest E30 0.15 Ethylenediamine (Innospec) disuccinate Sodium Chloride 3.6 Guar Activsoft C-17 0.18 Hydroxypropyltrimonium (Innospec) Chloride Disodium Miranol C2M Conc. 6.7 Cocoamphodipropionate (Rhodia) Sodium Methyl Cocoyl Pureact WS Conc. 6.7 Taurate (Innospec) Guar Gum Activsoft S (Innospec) 0.45 Glycerin 1.00 SLMI Pureact SLMI-85 11.2 (Innospec) Cocamide MEA Aminol CM Flakes 3.1 (Innospec) Canola Oil Rita Canola Oil (Rita) 9.00 Cocamidopropyl Betaine Mirataine BET C-30 10.00 (Rhodia) Trideceth-7 Carboxylic Pureact TA (Innospec) 3.5 Acid Citric Acid (50% soln) to pH 5.2-5.8 Preservative trace Fragrance trace Dye(s) trace

(28) The viscosity of the foaming body lotion of Example 16 was tested under different shear rates, on a viscometer with a T-Bar C Spindle, at 22 C. The results were as follows: 0.5 RPM=240,000 cps 1.0 RPM=140,000 cps 2.5 RPM=64,000 cps