ZA200206537B

ZA200206537B - Low PH high fatty acid vanishing cream.

Info

Publication number: ZA200206537B
Application number: ZA200206537A
Authority: ZA
Inventors: Rully Anjasmara Siswoyo; Dwiwahyu Haryo Suryo
Original assignee: Unilever Plc
Priority date: 2000-03-21
Filing date: 2002-08-15
Publication date: 2003-08-15
Also published as: AU2001256180A1; GB0006866D0; WO2001070188A1

Description

LOW pH HIGH FATTY ACID VANISHING CREAM

The present invention relates to stably suspended cosmetic vanishing creams of low pH.

Vanishing creams are popular around the world because they spread easily onto the skin giving a thin, semi-matte film which seems to disappear or “vanish”. They are also used to counteract shine which may arise from overactive sebaceous glands. Moreover, these creams counteract skin dryness to alleviate flaking, cracking and roughness.

The creams are usually formulated with high levels of stearic acid suspended in water by means of an emulsifying agent. Typically the emulsifying agent is a potassium or sodium soap formed by the in situ reaction of caustic potash or other alkali on a portion of the stearic acid.

Consequently, the formulations have a pH above 7, and usually substantially above, because of the presence of alkali. Humectants, such as glycerin, are normally also present in vanishing creams.

Emerging trends in skin care have required that vanishing cream formulations be adapted to incorporate skin benefit agents. For example, WO 99/37280 {Bartolone et al.) discloses vanishing creams which are formulated to include . alkali or alkaline earth metal salts of alpha-hydroxy carboxylic acids into order to achieve skin lightening . properties. The disclosure describes the new products as having a pH above 5. Care was taken 1n this prior art document not to incorporate acid versions of the alpha-

- 2 = hydroxy carboxylic acids into the formulations. %

Unfortunately, the beneficial properties of these skin benefit agents have not been realized in such formulations and thus, it was clear that further work was necessary in order to enhance the performance of vanishing creams.

In addition to alpha-hydroxy carboxylic acids it would also be desirable to incorporate other skin benefit agents. For example, U.S. Patent 5,482,710 (Slavtcheff et al.) discloses the use of alpha- and beta-hydroxycarboxylic acids in combination with salts of glycyrrhizinic acid, alpha- bisabolol and anti-microbial agents including triclosan.

Accordingly, the present invention aims to provide a vanishing cream having a relatively high level of fatty acid and a low pH to accommodate acidic skin benefit agents which enhance the performance of the formulation.

The present invention also aims to provide a cosmetic composition, particularly a vanishing cream of low pH, wherein skin benefit agents can be stably suspended in the composition.

These and other objects of the present invention will become more readily apparent from consideration of the following summary and detailed description.

A cosmetic composition is provided comprising: ] (1) from 5 to 50% by weight of a C12-Cpp fatty acid; (ii) from 0.1 to 20% by weight of a Cg-Cpy fatty acid substituted saccharide; wherein the composition has a pH from about 1 to about 6.5.

The applicants have surprisingly found that cosmetic vanishing creams can be stably formulated at a pH of about 6.5 or less by incorporation of a stabilizing amount of a

Cg-C22 fatty acid substituted saccharide. Vanishing creams of the present invention which have a high fatty acid content (over 5% of, for example, stearic acid) retain the traditional consumer benefits of such products even at low pH, namely good moisturization without greasiness/oiliness, ease of absorption, cool sensation and a matte finish.

Addition of acidic skin benefit agents results in improvements in the areas of rough/flaky skin, enhancement of skin cell renewal and reduction of pimples.

Consequently, a first essential component of the vanishing cream compositions of the present invention is a Ci12-Cyg fatty acid, preferably stearic acid. The fatty acid will be present in amounts ranging from 5 to 50%, preferably from 7 » to 40%, more preferably from 10 to 25%, optimally from 12 to 20% by weight of the composition. '

A second component of the vanishing cream compositions of the present invention is a Cg-Cpp fatty acid substituted . saccharide. Preferably, these components are Cg-Cp2 fatty acid substituted glucose materials, more preferably Cg-Cjy fatty acid and C1-C3 alkyl substituted glucose compounds.

Suitable Cg-Cpp fatty acid substituted saccharides include methyl glucose sesquistearate, ethyl glucose sesquistearate, propyl glucose sesquilstearate, methyl glucose sesquipalmitate, ethyl glucose sesquipalmitate, propyl glucose sesquipalmitate, methyl glucose sesquilaurate, ethyl glucose sesquilaurate, propyl glucose sesquilaurate, methyl glucose sesquibehenate, ethyl glucose sesquibehenate, propyl glucose sesquibehenate and any combinations thereof. Of these, the most preferred saccharide is methyl glucose sesquistearate (a CTFA and INCI nomenclature) available as

TEGO Care PS sold by Th. Goldschmidt AG. Amounts of the stabilizing agent may range from about 0.1 to about 20%, preferably from about 0.5 to about 10%, more preferably from about 1 to about 8%, optimally from about 2 to about 5% by weight of the composition.

An optional but advantageous substance which may be present in compositions of the present invention is an acidic skin benefit agent. Representative of this category are the alpha- and beta- hydroxy carboxylic acids. Illustrative of ¢ the beta-hydroxy carboxylic acids is salicylic acid. The alpha-hydroxy carboxylic acids are represented by formula I having the structure:

RI

: R—C —COOH 0

OH wherein R and rR may be the same or different and are selected from H, F, Cl, Br, alkyl, aralkyl or aryl groups which may be saturated or unsaturated, isomeric or nonisomeric, straight or branched chain, having 1 to 25 carbon atoms, or in a cyclic form having 5 or 6 ring members. In addition, R and rR: may be substituted with an

OH, CHO, COOH or alkoxy group having 1 to 9 carbon atoms.

The alpha-hydroxy acid exists as a free acid, and includes stereoisomers, and D, L, and DL forms thereof when R and R! are not identical.

Illustrative of this group of materials are: 2-hydroxyethanoic acid (glycolic acid); 2-hydroxypropanoic acid (lactic acid); 2-methyl 2- hydroxypropanoic acid (methyllactic acid); 2-hydroxybutanoic acid; 2-hydroxypentanoic acid; 2-hydroxyhexanoic acid; 2-hydroxyheptanoic acid; 2-hydroxyoctanoic acid; 2- hydroxynonanoic acid; 2-hydroxydecanoic acid; 2- hydroxyundecanoic acid; 2-hydroxydodecanoic acid (alpha- hydroxylauric acid); 2-hydroxytetradecanoic acid (alpha- hydroxymyristic acid); 2-hydroxyhexadecanoic acid (alpha- * hydroxypalmitic acid); 2-hydroxyoctadecanoic acid (alpha- hydroxystearic acid) ; 2-hydroxyeicosanoic acid (alpha- hydroxyarachidonic acid): 2-phenyl 2-hydroxyethanoic acid (mandelic acid}; 2,2-diphenyl 2-hydroxyethanoic acid

" woo1/70188 PCT/EP01/02344 (benzilic acid); 3-phenyl 2-hydroxypropanoic acid (phenyl : lactic acid); 2—phenyl, 2-methyl, 2-hydroxyethanoic acid (atrolactic acid); 2-(4’~-hydroxyphenyl) 2-hydroxyethanoic ) acid; 2-(4’ -chlorophenyl 2-hydroxyethanoic acid; 2-(3'~

S hydroxy-4’'-methoxyphenyl) 2-hydroxyethanoic acid; 2-(4" - hydroxy-3’ -methoxyphenyl)2-hydroxyethanoic acid; 37 -(2- hydroxyphényl) 2-hydroxypropanoic acid; 3-(4' -hydroxyphenyl) 2-hydroxypropanoic acid; and 2-(3',4’'-dihydroxyphenyl) 2- hydroxyethanoic acid.

Most preferred of this group of materials are glycolic acid, lactic acid, 2-hydroxyoctanoic acid or combinations thereof.

Levels of alpha-hydroxy alkanoic acids may range from about 0.1 to about 10%, preferably between about 0.2 and 1%, optimally between about 0.4 and 1% by weight of the composition.

In a particularly preferred embodiment, there will be present a mixture of both a beta-hydroxy carboxylic acid and an alpha-hydroxy carboxylic acid. For instance, the optimum combination is a mixture of salicylic acid and glycolic acid in a relative weight ratio from about 20:1 to about 1:20, preferably from about 10:1 to 1:1, optimally from about 3:1 to about 2:1.

Compositions of the present invention may also include a variety of anti-irritancy agents, particularly to counteract * any irritancy caused by the acidic skin benefit agents.

Suitable antli-irritancy agents include gluconolactone, borage seed oil, wild borage, dextran, alpha-bisabolol (extracted from chamomille), azulene (extracted from yarrow), resveratrol, petroselenic acid, and combinations ’ thereof. Each of these may be present at levels ranging from about 0.0001 to about 5%, preferably from about 0.001 to about 1%, optimally from about 0.01 to about 0.5% by weight of the composition.

Herbal extracts may also be included as components of the composition and are particularly effective for controlling the level of sebum/oil. Suitable extracts include dill, horseradish, oats, neem, beet, broccoli, tea, pumpkin, soybean, barley, walnut, flax, ginseng, poppy, avocado, pea, sesame, dandelion, wheat, nettle, cashew, pineapple, apple, asparagus, Brazil nut, chickpea, grapefruit, orange, cucumber, buckwheat, strawberry, ginko, tomato, blueberry, cowpea and grape extracts.

Other suitable herbal extracts include ivy horse chestnut, centella asiatica, rosmarinic acid, sericoside, ruscogenin, escin, escolin, betulinic acid, catechin and derivatives thereof. Each of these may be present in an amount ranging from about 0.00001 to about 2%, preferably between about 0.01 and about 0.5% by weight of the composition.

Anti-microbial agents may also be useful in compositions of the present invention. Typically the anti-microbial agents are selected from triclosan, tricarbanilide, tea tree oil, . farnesol, farnesol acetate, hexachlorophene, Cq4-C20 quaternary ammonium salts such as benzalconium chloride and } a variety of zinc or aluminum salts. Typically the zinc or aluminum salts are compounds such as zinc pyridinethione, zinc sulphate, zinc chloride, zinc phenolsulphonate,

© WO 0170188 PCT/EP01/02344 aluminum chloride, aluminum sulphate and aluminum : chlorhydrate. The anti-microbial agent may be present in amounts ranging from about 0.1 to about 5%, preferably from ) about 0.2 to about 1%, optimally about 0.3% by weight of the composition.

Compositions of the present invention ordinarily contain water as a carrier in amounts ranging from about 5 to about 95%, preferably from about 30 to about 90%, optimally from about 50 to about 85% by weight of the composition.

Emollient materials in the form of silicone oils or synthetic esters may be incorporated into the compositions of the present invention. These may be present in amounts ranging from about 0.1 to about 30%, preferably between about 1 and 20% by weight of the composition.

Silicone oils may be divided into the volatile and non- volatile variety. The term “volatile” as used herein refers to those materials which have a measurable vapor pressure at ambient temperature. Volatile silicone oils are preferably chosen from cyclic or linear polydimethylsiloxanes containing from about 3 to about 9, preferably from about 4 to about 5, silicon atoms.

Linear volatile silicone materials generally have viscosities less than about 5 centistokes at 25°C while cyclic materials typically have viscosities of less than . about 10 centistokes.

Nonvolatile silicone oils which are suitable as emollients . for the compositions of the present invention include polyalkyl siloxanes, polyalkylaryl siloxanes or polyether siloxane copolymers (e.g. dimethicone copolyol). Suitable non-volatile polyalkyl siloxanes include, for example, polydimethyl siloxanes with viscosities ranging from about 5 to about 100,000 centistokes at 25°C. Among the preferred non-volatile emollients which are useful in the present compositions are polydimethyl siloxanes having viscosities from about 10 to about 400 centistokes at 25°C.

Suitable ester emollients include: (1) alkenyl esters of fatty acids having 10 to 20 carbon atoms, such as methyl myristate, methyl stearate, oleyl myristate, oleyl stearate, or butyl oleate; (2) ether-esters such as fatty acid esters of ethoxylated fatty alcohols; (3) polyhydric alcohol esters, such as ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and di-fatty acid esters, polyethylene glycol (200-6000) mono- and di-fatty acid esters, propylene glycol mono- and di- fatty acid esters, polypropylene glycol 2000 monooleate, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated } glyceryl monostearate, 1,3-butylene glycol monostearate, 1,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene ’ sorbitan fatty acid esters; (4) wax esters such as beeswax, spermaceti, myristyl myristate, stearyl stearate; (5) sterols esters, such as cholesterol fatty acid esters.

The preferred ester emollients are C;-C3 alkyl fatty esters such as methyl stearate, methyl myristate and methyl palmitate. Cg-Cz0 alkyl esters of fatty acids such as cetyl palmitate and myristyl myristate are also particularly preferred.

Humectants of the polyhydric alcohol-type may also be included in the compositions of the present invention. The humectant helps to increase the effectiveness of the emollient, reduces scaling, stimulates removal of built-up scale and generally improves skin feel. Typical polyhydric alcohols include glycerol, polyalkylene glycols and more preferably alkylene polyols and their derivatives, including propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol and derivatives thereof, sorbitol, hydroxypropyl sorbitol, isoprene glycol, hexylene glycol, 1,3-butylene glycol, 1,2,6-hexanetriol, ethoxylated glycerol, propoxylated glycerol and mixtures thereof. The amount of humectant may range anywhere from about 0.5 to about 30%, preferably between 1 and 15% by weight of the composition.

Thickeners/viscosifiers in amounts of up to about 5% by ) weight of the composition may also be included. The skilled person would appreciate that the precise amount of thickener required may vary depending upon the consistency and thickness of the composition desired. Suitable thickeners include xanthan gum, sodium carboxymethyl cellulose, hydroxyalkyl and alkyl celluloses (particularly hydroxypropyl cellulose), sclerotium gum and polyacrylamide dispersions in isoparaffin such as those sold by Seppic Inc. under the Sepigel® 305 trademark.

Preservatives may also desirably be incorporated into the cosmetic compositions of the present invention to protect against the growth of potentially harmful microorganisms.

Suitable traditional preservatives include alkyl esters of para-hydroxybenzoic acid. Other preservatives which have more recently come into use include hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Cosmetic chemists are familiar with appropriate preservatives and routinely choose them to satisfy the preservative challenge test and to provide product stability. Particularly preferred preservatives are disodium EDTA, phenoxyethanol, methyl paraben, butyl paraben, propyl paraben, imidazolidinyl urea (commercially available as Germall 1157), sodium dehydroacetate and benzyl alcohol. The preservatives should be selected having regard for the use of the composition and possible incompatibilities between the preservatives and other . ingredients in the emulsion. The preservatives are preferably employed in amounts ranging from about 0.012% to about 2% by weight of the composition.

Advantageously, compositions of the present invention may contain glycyrrhizinic acid and salts thereof. These may be of the alpha or beta glycyrrhizinic variety. Particularly useful are the alkali metal and ammonium salts such as disodium and dipotassium glycyrrhizinate. Amounts of these substances may range from about 0.0001 to about 3%, preferably from about 0.01 to about 1.0%, optimally from about 0.1 to about 0.5% by weight of the composition.

Colorants and fragrances may also be included in the compositions of the present invention. These may be present in amounts ranging from about 0.05 to about 5%, preferably between about 0.1 and about 3% by weight of the composition.

Compositions of the present invention will have a pH ranging from about 1 to about 6.5, preferably from about 2 to about 6.0, more preferably from about 3 to about 5.5, optimally from about 3.5 to about 4.5.

Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material are to be understood as modified by the word “about”.

The following examples will more fully illustrate the embodiments of this invention. All parts, percentages and proportions referred to herein and in the appended claims are by weight unless otherwise illustrated. "a

EXAMPLES 1-8

The following examples are illustrative of vanishing cream formulations according to the present invention.

Vanishing Cream [CoMpoNENTS |Exmwpl®

I FSR 2 TA 7 SU FT KA A 0 0

Lauric Acid ~~ [2.00 ]2.00[4.00 [4.00 [4.00 [1.00 ]1.00]10.00

Methyl Glucose 2.25 3.00 {2.00 2.00 2.25 3.25 1.00

Sesguistearate

Lactic Acid [1.00 [-- [3.00 [4.00 [7.00 [-- [1.00[--

Glycolic Acid | -- _j1.000-- J-- [-- "71.00 |-- [3.00

Cetyl Palmitate

Salicylic Acid

Methyl Paraben

Dipotassium 0.15 0.15] 0.15 0.15 0.15 0.15 0.15 0.15

Glycyrrhizinate

Silicone DC 200

Propyl Paraben

EXAMPLE 9

A series of stability tests were conducted to establish the performance of fatty acid saccharides as stabilizing agents for low pH vanishing creams. Table I provides formulations : of compositions which were comparatively tested.

TABLE I

: ms Te Ip 15.00 [15.00 [15.00 [15.00

Methyl Glucose 2.25

Sesquistearate

Lauryl Polyglucose [-- ]1.69 12.25 [2.81

Cetyl Palmitate

Salicylic Acid

Methyl Stearate

Myristic Acid

Methyl Paraben

Dipotassium 0.15 0.15 0.15 0.15

Glycyrrhizzinate

Silicone DC 200-50

Propyl Paraben

Stability was determined in a 6 months storage stability test. Samples were stored for six months with temperatures alternating from 25°C (room temperature) to 6°C to 45°C and exposed to sunlight. Samples with satisfactory stability within the six month period may normally be expected to be stable for about 2-3 years in the marketplace.

Formulation A employing methyl glucose sesquistearate as a stabilizer provided a stable emulsion without any phase : separation. By contrast, replacement with an alkyl polyglucoside such as lauryl polyglucose at 75%, 100% and 125% of the methyl glucose sesquistearate levels (compare formulations B, C and D respectively) resulted in phase

The foregoing description and examples illustrate selected embodiments of the present invention. In light thereof variations and modifications will be suggested to one skilled in the art, all of which are within the spirit and purview of this invention.

D

Claims

oN WO 01770188 PCT/EP01/02344 I - 16 - . CLAIMS | oo

1. A cosmetic composition comprising: : : (i) from 5 to 50% by weight of a C32-Cpo fatty acid; (ii) from 0.1 to 20% by weight of methyl glucose sesquistearate; wherein the composition has a pH from about 1 to about 6.5.

2. A composition according to claim 1 wherein the C33-Czo fatty acid is stearic acid.

3. A composition according to claim 1 or claim 2 wherein the C;2-Coo fatty acid is present in an amount from about 10 to about 25% by weight.

4. A composition according to any one of the preceding claims further comprising an acidic skin henefit agent.

5. A composition according to claim 4 wherein the acidic skin benefit agent is selected from alpha-hydroxy carboxylic acids, beta-hydroxy carboxylic acids or mixtures thereof.

6. A composition according to claim 5 wherein the alpha- hydroxy carboxylic acids are selected from glycolic acid, lactic acid, 2-hydroxyoctanocic acid or combinations thereof.

’ 7. A composition according to claim 5 or claim 6 wherein , the beta-hydroxy carboxylic acid is salicylic acid. oo AMENDED SHEET - oo 2003 04-0 7 oo n \ FE

8. A composition according to any one of the preceding claims wherein the pH ranges from 2 to 6.0.

9. A composition according to any one of the preceding claims further comprising from about 0.0001 to about 3% by weight of glycyrrhizinic acid or a salt thereof. AMENDED SHEET 2003 -04- 07