AU2008249532A1

AU2008249532A1 - Cleansing composition

Info

Publication number: AU2008249532A1
Application number: AU2008249532A
Authority: AU
Inventors: Craig Joseph Davies; Phillip Michael Green; Paul Lawrence Heffernan; Samantha Jane Thomas
Original assignee: Manchester Business Park
Current assignee: Manchester Business Park
Priority date: 2007-12-06
Filing date: 2008-11-28
Publication date: 2009-06-25
Also published as: PL386709A1; GB0723849D0; GB2455404A; GB0821731D0; GB2455404B

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "CLEANSING COMPOSITION" The following statement is a full description of this invention, including the best method of performing it known to me/us: Cleansing Composition The present invention relates to a cleansing composition, in particular to a 5 foaming and cleansing composition which is preferably mild to the skin and provides excellent moisturising properties. Products which not only cleanse but which also moisturise the skin are desirable to consumers for a variety of reasons such as the convenience of 10 needing to apply only a single product to achieve both cleansing and moisturising. In addition, the use of a "dual" cleansing and moisturising product will reduce the occurrence of the sometimes unpleasant taut, dry feeling of the skin experienced as a result of the drying effect observed with some cleansing only products. 15 However, it is often difficult to ensure absorption of the moisturising component into the skin when delivery is from an aqueous composition. As such, numerous attempts have been made in the art to improve the delivery of moisturisers onto the skin from products of this type. To date, 20 research in this area has adopted one of two approaches, as follows: (i) The use of mild surfactants to prevent skin dryness, reducing the need for the presence and good absorption of moisturiser; and (ii) The use of high levels of moisturisers, overcoming the problem of 25 poor delivery as the presence of excess moisturiser ensures that some, if even a low percentage of the overall moisturiser present in the composition, reaches and is absorbed onto the skin. Whilst the use of mild surfactants offers benefits to the skin, they are often 30 rejected by consumers. This is because a trade-off exists between mildness and the ability of the product to lather sufficiently and also for the product to be of an acceptable viscosity for consumers to use. To overcome these two issues, the most common approach has been to 2 increase the overall surfactant level of the product but this then leads to a product which is harsher to skin (since increased total surfactant concentration is detrimental to mildness) and is more costly to produce. Another approach has been to use thickening systems. Whilst this might 5 overcome the issue of the product viscosity, it does not address the issue of lather and it has been found that any thickening system selected has to be carefully chosen to avoid additional problems being created (such as instability and/or foam depression). 10 In one recent example, Piterski et al describe a mild foaming cleanser composition in WO 02/062936. This document seeks to overcome the twin issues of viscosity and foaming by the use of 'instant foaming' packaging. The use of packaging to address the problem is, however, a costly solution and does not address the fact that consumers dislike using thin product 15 formulations. The most common approach in marketed moisturising personal wash products has been to produce a structured surfactant product which contains high levels of oils to moisturise the skin. High levels of surfactants 20 are therefore required to hold this oil in suspension and also to allow the product to lather sufficiently. This has the problem that a high level of surfactants will be detrimental to skin mildness but also leads to a number of other problems such as product instability, higher cost (for both formulation and process), the need for more complex processing, and a 25 higher base odour. In addition, as it is difficult to control the levels of oils delivered to the skin, an undesirable greasy skin feel may be observed. Whilst several attempts have been made to overcome these issues, the success rate has been low and the solutions inefficient as surfactants and oils are antagonistic in terms of lather, mildness and effect on skin 30 hydration. This is because the high surfactant systems needed in the typical high-moisturiser prior art cause stripping of moisturiser from the skin and damage to skin proteins resulting in a reduction of skin barrier function.

3 Thus a need still exists for personal cleansing products which offer some or all of the properties of mildness, skin moisturisation, production of a consumer acceptable amount of lather, which have the correct consumer aesthetics, and can be produced in a cost-effective manner. 5 There is therefore provided, in accordance with a first aspect of the invention, a foaming, cleansing composition comprising: (i) a mild surfactant system comprising in the range about 0.1 to 20% 10 w/w of the total composition; (ii) a humectant system comprising in the range about 0.1 to 20% w/w of the total composition; (iii) from 0.1 to 10% w/w of the total composition of one or more glyceryl ester(s); and 15 (iv) a thickening system comprising in the range 0.1 to 5% w/w of the total composition. The inventive composition has been shown to be extremely mild to the skin. The composition optimises the properties of mildness, skin 20 moisturising, lather and consistency. In accordance with a further aspect of the invention there is provided a method of making a cleansing composition in accordance with the first aspect of the invention comprising the steps of combining a surfactant 25 system, humectant system, glyceryl ester and thickening system. In accordance with an additional aspect of the invention there is also provided a method of cleansing the skin comprising applying the cleansing composition of the first aspect of the invention to the skin, and rinsing off. A 30 further aspect of the invention provides a method of moisturising the skin comprising applying the cleansing composition of the first aspect of the invention to the skin, and rinsing off.

4 As noted above, the invention provides a solution to the problem of producing a cleansing composition which: (i) is of low cost and complexity for formulation, packaging and manufacture; 5 (ii) delivers moisture to the skin without any greasiness either in-use or post-use; and (iii) meets the expected consumer requirements for a washing product with no compromise for viscosity, lather or in-use performance. 10 The benefits in terms of cost come from providing a composition which need not include high levels of oils or surfactant, does not require expensive packaging, and can be produced without the need for high temperature or complex processing. 15 The benefits in terms of reduced greasiness come by avoiding the use of high levels of moisturiser, instead moisture is delivered more efficiently to the skin by using a combination of mild surfactant, humectants and only low levels of water-soluble glyceryl ester(s). 20 Benefits in terms of consumer requirements are available from providing high lather through the combination of a mild surfactant system, preferably a combination of alkyl sulphates or alkyl ether sulphates blended with mild surfactants; combined with the use of a thickening system optionally based on a layered silicate thickener combined with an organic gum (which 25 provides the required product viscosity without compromising lather generation or quality). In a preferred embodiment, the surfactant comprises about 5 to 15% w/w of the total composition. As used herein the w/w percentages quoted for the 30 surfactants are the w/w percentage of the active matter rather than the total surfactant as supplied.

5 The mild surfactant system is optionally comprised of a combination of components selected from: (A) an alkyl sulphate and/or an alkyl ether sulphate; (B) an alkyl and/or an alkyl amidopropyl betaine; and 5 (C) one or more surfactants classed as non-irritant to slightly irritant as defined by having an (L/D) ratio greater than 10 (RBC haemolysis/denaturation, as defined in Pape, W.J.W., Pfannenbecker, U. & Hoppe, U. (1987). "Validation of the red blood cell test as an in vitro assay for the rapid screening of irritation potential of surfactants". Molecular 10 Toxicology, 1, 525-536., the disclosure of which is herein incorporated by reference). In some embodiments component (C) will comprise at least 20% by weight of the total surfactant system. In some embodiments the ratio of 15 components (A) to (B) will be in the range from 5:1 to 1:5. In further embodiments component (C) will comprise at least 20% by weight of the total surfactant system and the ratio of components (A) to (B) will be in the range from 5:1 to 1:5. 20 In one embodiment of the invention the ratio of components (A) to (B) will be in the range from 1:1 to 1:5, more preferably in the range from 1:1 to 1:2, and most preferably from 1:1.5 to 1:2. Generally the most preferable ratio is about 1:1.75. Preferably, the composition comprises more of component (B) than Component (A). 25 The alkyl sulphates and alkyl ether sulphates that comprise component (A) offer a high foaming component to the cleansing composition of the invention. The alkyl sulphates and alkyl ether sulphates will typically include alkyl groups of from 8 to 22, carbon atoms and may be 30 unsaturated. The alkyl ether sulphates will often contain from 1 to 10 ethylene oxide or propylene oxide units per molecule.

6 The preferred alkyl sulphates and alkyl ether sulphates for use in the invention include sodium lauryl sulphate, sodium lauryl ether sulphate 1 EO, 2EO and 3EO, ammonium lauryl sulphate and ammonium lauryl ether sulphate 1EO, 2EO and 3EO. The most preferred sulphate surfactant is 5 sodium lauryl ether sulphate used either alone or in combination with other sulphate surfactants. The alkyl or alkyl amidopropyl betaine that comprises component (B) includes simple betaines of formula: 10 R 2 101

R'-N*-CH

2 CO2~

R

3 15 and amido betaines of formula: R 2 20 R1 - CONH-(CH 2 )m-N*-CH 2 CO2~ R 3 where m is 2 or 3. In both formulae R 1 is alkyl or alkenyl of 7 to 18 carbon 25 atoms and R 2 and R 3 are each independently alkyl, hydroxyalkyl or carboxyalkyl of 1 to 3 carbon atoms; R 1 may, in particular, be a mixture of

C

12 and C 14 alkyl groups derived from coconut so that at least half, preferably at least three quarters, of the group R 1 has 10 to 14 carbon atoms. R 2 and R 3 are preferably methyl. In some embodiments it is 30 preferred to include cocoamidopropyl betaine, lauramidopropyl betaine or combinations thereof.

7 The mild surfactants that comprise component (C) can be selected from anionic, non-ionic and/or amphoteric surfactants and may optionally be selected from: amphoacetates, sarcosinates, sulfosuccinates, amine oxides, ether carboxylates, sultaines, alkyl polyglucosides, sucrose esters, 5 alkanolamides, acyl lactates, ethoxylated fatty alcohols, or combinations thereof. In some examples it is preferred that the mild surfactant be a sulfosuccinate, often a cocamidosulfosuccinate. In some embodiments, the humectant system will be present in the range 5 10 to 15% w/w of the total composition. A variety of humectants can be employed, such as urea, glycerine, sorbitol, polyglycerol, sodium PCA, natural betaine (trimethyl glycine), lactate salts or combinations thereof. The generally preferred humectants include urea, sodium PCA, glycerine, lactate salts, and combinations thereof. 15 The glyceryl esters may comprise in the range about 1 to 5% w/w of the total composition. As used herein, the description "glyceryl ester(s)" is also intended to cover PEG modified glyceryl esters. These can include, among others, glyceryl oleate, glyceryl laurate (and other alkane/alkenyl chains 20 e.g. C8 to C22, mono-, di- and tri- esters and mixtures thereof), glycereth-2 cocoate, PEG-7 glyceryl cocoate, PEG-6 caprylic/capryl glycerides, and combinations thereof. In some embodiments, the preferred glyceryl esters are selected from glyceryl oleate, PEG-7 glyceryl cocoate, PEG-6 caprylic/capryl glycerides and combinations thereof. 25 In a further embodiment, the thickening system comprises in the range about 1 to 3% w/w of the total composition. The thickening system may, in some examples, consist of a combination of layered silicate thickener (both natural and synthetic) and organic gums (such as, although not exclusively, 30 xanthan gum, guar gum, carrageenan gum, locust bean gum, alginates and celluloses). In a preferred embodiment the silicate thickener is synthetic. Where gums are present, it is often the case that these will be selected from xanthan gum, carrageenan gum and combinations thereof.

8 Illustrative silicates include sodium magnesium silicate, aluminium magnesium silicate, magnesium silicate, aluminium silicate, chemically modified magnesium aluminium silicate, smectite clay, bentonites, hectorites, pyrogenic colloidal silica, organically modified montmorillonite 5 clay, hydrated aluminium silicate, fumed silica, barium silicate, calcium silicate, alumina, zeolite and combinations thereof. Particularly preferred is a silicate selected from sodium magnesium silicate (available commercially under the trademark Laponite) and aluminium magnesium silicate (available commercially under the trademarks of Gel White and Veegum). 10 Advantageously, the silicates will be finally divided powders having an average particle size ranging from about 0.0001 micron to about 50 micron, preferably from about 0.001 micron to about 10 micron, more preferably from about 0.01 to about 1.5 micron. 15 The thickening system can also optionally incorporate insoluble materials, these may be selected from pigments (such as TiO 2 ), high molecular weight silicones, wax based pearlescent agents, mica based shimmering agents, exfoliants, encapsulates (containing, for instance, fragrances or 20 benefit agents), anti-dandruff agents, antibacterial agents and combinations thereof. Further examples of components suitable for incorporation into the inventive cleansing composition are given in the International Cosmetic 25 Ingredient Dictionary, Seventh Edition, 1997, published by CTFA (The Cosmetic, Toiletry & Fragrance Association), incorporated herein by reference. In addition a wide variety of other optional ingredients can be included for 30 aesthetics or as adjunct ingredients. These include but are not limited to fragrances, preservatives, dyes, chelating agents and combinations thereof.

9 In accordance with the method of preparing a cleansing composition as defined above, it is preferred that the steps required to combine the surfactant system, the humectant system, the glyceryl ester(s) and the thickening system occur at ambient temperature. In addition, it is preferred 5 in some embodiments that the thickening system of the invention is first prepared and the other components of the cleansing composition added thereto with mixing. This offers a stable solution throughout the preparation process and reduces the incidence of separation of the composition. It is also preferred that the glyceryl ester(s) be added after the surfactants in the 10 composition. Unless otherwise stated each of the integers described in the invention may be used in combination with any other integer as would be understood by the person skilled in the art. Further, although all aspects of the 15 invention preferably "comprise" the features described in relation to that aspect, it is specifically envisaged that they may "consist" or "consist essentially" of those features outlined in the claims. In particular, it should be noted that the cleansing composition of the first 20 aspect of the invention may comprise a mild surfactant system, a humectant system, glyceryl ester(s) and a thickening system as defined. Unless otherwise stated all percentages appearing in the specification are percentages by w/w of the composition being described. In addition, 25 unless otherwise stated, all numerical values appearing in this application are to be understood as being modified by the term "about". Examples The following table discloses examples prepared in accordance with the 30 invention. Each example includes a total surfactant content of 10.0%.

10 The examples are either viscous pourable liquids or dispensable gels and all demonstrate consumer desirable lathering, mildness and moisturising properties. 5 The numbers in the table refer to inclusion levels as % w/w. For the surfactants this is expressed as active matter rather than "as supplied" with the exception of Lamesoft P065 (trade name from Cognis GmbH) which is a blend of Coco Glucoside and Glyceryl oleate (approx. 30% each). Ingredient A B C D E F Glycerine 10 5.0 4.0 5.0 2.0 Urea 5.0 4.0 4.0 Sodium PCA 2.0 1.0 Trimethyl glycine (natural betaine) 4.0 Lauramidopropyl betaine 1.0 3.0 4.0 3.0 3.0 4.0 Sodium lauryl ether sulphate 3.0 3.0 3.0 3.5 3.5 3.0 Disodium PEG-4 cocamido MIPA sulfosuccinate 3.0 4.0 2.0 2.0 3.0 Coco glucoside 3.0 3.0 Lamesoft P065 5.0 5.0 Glyceryl oleate 1.5 1.0 1.0 PEG-7 glyceryl cocoate 2.0 1.0 1.0 PEG-6 capric/caprylic glycerides 1.0 Tetrasodium EDTA 0.16 0.16 0.16 0.16 0.16 0.16 Preservative - 0.08 0.08 0.08 0.08 0.08 0.08 11 Ingredient A B C D E F Kathon CG Lactic acid 88% 1.25 1.0 1.0 1.3 Citric acid monohydrate 1.0 1.0 Sodium magnesium silicate (synthetic) 1.5 2.0 1.0 1.5 Magnesium aluminium silicate (natural) 2.0 2.0 Xanthan gum 0.5 1.0 1.0 0.5 Carrageenan gum 0.5 0.5 Sodium carboxymethyl cellulose 0.5 Fragrance 0.5 0.5 0.5 0.5 0.5 0.5 Balanc Balanc Balanc Balanc Balanc Balanc Water e e e e e e % of total surfactant system having an L/D ratio >10 60 40 30 35 35 30 Ingredient G H I J K L Glycerine 3 5 2 6 2 Urea 3 6 4 8 Cocamidopropyl 5.5 3.5 5 4.5 3.5 3.5 betaine Sodium Laureth 2 3 3 2.5 3 3 Sulfate 12 Disodium 2 3.5 PEG-4 Cocamido

MIPA

sulfosuccinate Disodium 2.5 3 3.5 PEG-5 Laurylcitrate Sulfosuccinate Coco 3.5 Glucoside Glyceryl oleate 1.25 1 1.5 1.2 PEG-7 glyceryl 1.25 2 2 cocoate PEG-6 1 1.5 Capric/Caprylic Gycerides Tetrasodium 0.16 0.16 0.16 0.16 0.16 0.16 EDTA Preservative - 0.1 0.1 0.1 0.1 0.1 0.1 Kathon CG Lactic Acid 1 1 1 88% 13 Citric acid 1 1 1 monohydrate Sodium 1.5 1 1.5 1.5 Magnesium Silicate (synthetic) Magnesium 2 2 aluminium silicate (natural) Xanthan 0.5 0.5 1 0.5 0.5 0.5 Gum Fragrance 0.5 0.5 0.5 0.5 0.5 0.5 Water Balance Balance Balance Balance Balance Balance % of total 25 35 20 30 35 35 surfactant system having an L/D ratio >10 Preparation Methodology The examples of the invention were prepared as follows. A formulation 5 quantity of water was placed in a suitable vessel at ambient temperature. Silicate thickener was then added and mixed until fully hydrated and dispersed. The organic gum thickener was then added and mixed until fully hydrated and dispersed. Humectant and subsequently EDTA (ethylenediaminetetraacetic acid) were then added with mixing until 10 homogenous. The citric or lactic acid were then added slowly as an aqueous solution, and the surfactants added in any order with mixing until a homogeneous solution obtained.

14 The glyceryl esters and fragrance were premixed and added slowly to the composition. Where present, Lamesoft P065 was then added with mixing, followed by preservative. The resulting mixture was then mixed for at least 15 minutes to ensure homogeneity. 5 It should be appreciated that the compositions and methods of the invention are capable of being incorporated in the form of a variety of embodiments, only a few of which have been illustrated and described above. 10

Claims

1. A cleansing composition comprising: 5 (i) a mild surfactant system comprising in the range from about 0.1 to 20% w/w of the total composition; (ii) a humectant system comprising in the range from about 0.1 to 20% w/w of the total composition; (iii) from 0.1 to 10% w/w of the total composition of one or more glyceryl 10 ester(s); and (iv) a thickening system comprising in the range from 0.1 to 5% w/w of the total composition.

2. A cleansing composition according to claim 1, wherein the mild 15 surfactant system comprises a combination of components selected from: (A) an alkyl sulphate and/or an alkyl ether sulphate; (B) an alkyl and/or an alkyl amidopropyl betaine; and (C) one or more surfactants having an (LID) ratio greater than 10. 20

3. A cleansing composition according to claim 2, wherein component (C) comprises at least 20% by weight of the total surfactant system.

4. A cleansing composition according to claim 2 or claim 3, wherein the ratio of components (A) to (B) is in the range from 5:1 to 1:5. 25

5. A cleansing composition according to claim 4, wherein the ratio of components (A) to (B) is in the range from 1:1 to 1:5.

6. A cleansing composition according to claim 5, wherein the ratio of 30 components (A) to (B) is in the range from 1:1 to 1:2.

7. A cleansing composition according to claim 6, wherein the ratio of components (A) to (B) is in the range from 1:1.5 to 1:2. 16

8. A cleansing composition as claimed in claim 1, wherein the composition comprises more of component (B) than Component (A).

9. A cleansing composition according to any preceding claim 5 comprising about 5 to 15% w/w, of the total composition, of surfactant system.

10. A cleansing composition according to any preceding claim comprising about 5 to 15% w/w, of the total composition of humectant 10 system.

11. A cleansing composition according to any preceding claim, wherein the humectant is selected from urea, glycerine, sorbitol, polyglycerol, sodium PCA, trimethyl glycine, lactate salts and combinations thereof. 15

12. A cleansing composition according to any preceding claim comprising from about 1 to 5% w/w of the total composition of glyceryl ester(s).

13. A cleansing composition according to any preceding claim, wherein 20 the glyceryl ester(s) is selected from glyceryl oleate, glyceryl laurate, glycereth-2 cocoate, PEG-7 glyceryl cocoate, PEG-6 caprylic/capryl glycerides, and combinations thereof.

14. A cleansing composition according to any preceding claim 25 comprising about 1 to 3% w/w, of the total composition, of thickening system.

15. A cleansing composition according to any preceding claim, wherein the thickening system is selected from a combination of layered silicate 30 thickener and organic gums. 17

16. A method of making a cleansing composition according to any preceding claim comprising the steps of combining a surfactant system, humectant system, glyceryl ester(s) and thickening system. 5

17. A method of cleansing the skin comprising applying a cleansing composition according to any of claims 1 to 15 to the skin, and rinsing off.

18. A method of moisturising the skin comprising applying a cleansing composition according to any of claims 1 to 15 to the skin, and rinsing off. 10