WO2004078159A1

WO2004078159A1 - Low irritation lathering formulations

Info

Publication number: WO2004078159A1
Application number: PCT/EP2004/002498
Authority: WO
Inventors: Véronique MAHE; Otto Von Stetten; Herman Hensen; Jessica Schneider; Celia Sander; Joseph Koester
Original assignee: Johnson and Johnson Consumer France SAS
Current assignee: Johnson and Johnson Consumer Holdings France SAS
Priority date: 2003-03-07
Filing date: 2004-03-08
Publication date: 2004-09-16
Anticipated expiration: 2005-09-07
Also published as: CN1756526A; BRPI0408144A; KR20050120635A; MXPA05009571A; CA2518213A1; JP2006519808A; EP1601341A1; AU2004216853A1

Abstract

This invention relates to lathering skin-care products containing particular surfactant systems that provide good lathering and low irritation, said surfactant system containing: (a) one or more alkyl or alkenyl oligoglucosides, (b) one or more amphoteric surfactants, and (c) one or more anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic cosurfactants [(a + b) : c] being such that it is in the range of 1.1 : 1 to 10 : 1.

Description

Low Irritation Lathering Formulations

Brief description of the invention

This invention relates to lathering cleansing formulations containing particular surfactant systems that provide good lathering and low irritation.

Background of the Invention

Surfactants are essential components in cleansing formulations such as in shampoos, bath and shower gels, providing cleaning and de-fatting properties as well as lathering capacity. Although the latter is of less importance to the actual performance of a cleansing composition, nevertheless the consumer perceives it as an essential quality of a cleansing composition. Current cleansing formulations contain mixtures of various types of surfactants that provide the above-mentioned qualities.

Anionic surfactants are added because of their good lathering properties. Apart from providing good basic quantities of lather, they also have been found to add to the quality of the lather, in particular to its constitution and to the lather kinetics. Anionic surfactants give lather that is stable, i.e. that does not collapse and remains present for a sufficiently long period of time, even in the presence of fats and hard water. A problem associated with the use of anionic surfactants is their tendency to dry out the skin upon frequent use and to generate intolerance towards this type of surfactants. This in particular is the case in sensitive skin types and in applications for babies. Another problem associated with anionic surfactants is their tendency to cause irritation and stinging, in particular to the eyes and the sensitive skin area around the eyes.

To increase skin tolerability further surfactants are added as co-surfactants, but these have been found to negatively impact the lathering performance of the anionic

CONF.R.V.AT50N COPY surfactants. Therefore only smaller amounts of co-surfactants can be added in cleansing formulations.

WO 97/26860 discloses conditioning shampoo compositions which are capable of cleansing and conditioning the hair, comprising a mixture of anionic, nonionic and amphoteric surfactants and a conditioning system comprising at least two particular conditioning polymers.

WO 98/24409 discloses aqueous compositions of body-cleansing agents with strong foaming action that contain anionic surfactants, alkyl(oligo)glucosides, and a combination of zwitterionic surfactants and ampholytic surfactants. Although the disclosed formulations are taught to have good foaming properties and to be well tolerated by the skin, they still contain relatively high concentrations of anionic surfactants, which is necessary for the foaming properties of these compositions but nevertheless make them not completely satisfactory in terms of mildness, in particular mildness to the eyes.

Hence there is a need to provide lathering cleansing formulations for personal use, and in particular to provide shampoos, that have good dermal tolerability, more specifically for sensitive skin types and babies. There is an additional need to provide lathering cleansing compositions and in particular shampoos that are non-irritating to the skin and in particular to the eyes and the area around the eyes. There is a further need for such formulations that have adequate cleansing capacity, are stable and provide sufficient amounts of lather of good quality and stability.

The formulations of the present invention wherein the content of anionic surfactants is reduced, nevertheless provide good lathering quality and show reduced skin irritation and decreased stinging of the eyes. Moreover it has been found that the total content of surfactants in the formulations of the invention can be lowered without negatively impacting their cleaning and lathering performance. Summary of the invention

The present invention relates to lathering skin-care formulations comprising a surfactant system containing: (a) one or more alkyl or alkenyl oligoglucosides,

(b) one or more amphoteric surfactants and

(c) one or more anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.1 : 1 to 10 : 1, and wherein the Trans-Epithelial Permeability (TEP) value of the formulation is equal or above about 1.95.

In a further aspect there are provided lathering skin-care formulations comprising a surfactant system containing: (a) one or more alkyl or alkenyl oligoglucosides,

(b) one or more amphoteric surfactants and

(c) one or more anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.1 : 1 to 10 : 1, and wherein the total concentration of betaine surfactants does not exceed about 2 weight-%.

Preferred are formulations wherein the total concentration of betaine surfactants does not exceed 1.5%, more preferred are formulations wherein the total concentration of betaine surfactants does not exceed 1 weight-%. Of particular interest are formulations having substantially no betaine content.

In an alternative aspect, this invention relates to lathering skin-care formulations as mentioned in this specification that contain at least about 2 weight-% of one or more alkyl or alkenyl oligoglucosides. Of particular interest are those formulations containing at least about 3 weight-% of one or more alkyl or alkenyl oligoglucosides. Of particular interest are any of the formulations as specified above or hereinafter having a TEP value which is equal or above about 1.95, or alternatively, which is equal to or above 2.00.

Of further preference are formulations according to this invention wherein the total concentration of anionic surfactants is lower than 7 weight-%, in particular lower than 5 weight-%, more in particular lower than 4 weight-%, or lower than 3 weight-%, relative to the total weight of the formulation.

In preferred embodiments this invention provides lathering skin-care formulations comprising a surfactant system containing:

(a) one or more alkyl or alkenyl oligoglucosides;

(b) one or more amphoteric surfactants selected from the group consisting of amphoalkanoates, amphodialkanoates, aminoalkanoates, and imino alkanoates; (c) one or more anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.5 : 1 to 10 : 1.

A particular feature of this invention comprises the fact that the anionic surfactants are present in a lesser amount than the sum of all non-anionic surfactants. Therefore the anionic surfactants are referred to as 'co-surfactants'.

In still a further aspect, the present invention concerns the use of a mixture comprising components (a), (b) and (c) as specified herein as a surfactant system in a lathering cleansing formulation for personal use.

Detailed description of the invention

Whenever used in this specification, any percentage is a weight percentage, expressing the weight-by-weight ratio of the ingredient relative to the total weight of the formulation. As used herein a, b and c in e.g. [(a + b) : c] and other equations refers to the total weight amount of the components (a), (b) and (c) respectively in the various definitions of the surfactant combinations in the formulations of the present invention.

Alkyl and alkenyl oligoglucosides

The formulations of the invention contain alkyl or alkenyl oligoglucosides, which are known nonionic surfactants, which correspond to formula (I):

R¹0-[G]_P (I)

wherein R¹ is an alkyl and/or alkenyl group containing 4 to 22 carbon atoms, G is a sugar unit containing 5 or 6 carbon atoms and p is a number of 1 to 10. These glucosides may be obtained by art-known preparative methods and a number of these ingredients are commercially available.

The alkyl and or alkenyl oligoglucosides may be derived from aldoses or ketoses containing 5 or 6 carbon atoms, preferably glucose. Accordingly, the preferred alkyl and/or alkenyl oligoglucosides are alkyl and/or alkenyl oligoglucosides. The index p in general formula (I) indicates the degree of ohgomerization (DP), i.e. the distribution of mono- and oligoglucosides, and is a number of 1 to 10. Whereas p in a given compound must always be an integer and, above all, may assume a value of 1 to 6, the value p for a certain alkyl oligoglucoside is an analytically determined calculated quantity, which is generally a broken number. Alkyl and/or alkenyl oligoglucosides having an average degree of ohgomerization p of 1.1 to 3.0 are preferably used. Alkyl and or alkenyl oligoglucosides having a degree of ohgomerization of less than 1.7 and, more particularly, between 1.2 and 1.5 are preferred from the applicational perspective. The alkyl or alkenyl group R¹ may be derived from primary alcohols containing 4 to 11 and preferably 8 to 10 carbon atoms. Typical examples are butanol, caproic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and the technical mixtures thereof obtained, for example, in the hydrogenation of technical fatty acid methyl esters or in the hydrogenation of aldehydes from Roelen's oxosynthesis. Alkyl oligoglucosides having a chain length of C₈ to C₁₀ (DP = 1 to 3), which are obtained as first runnings in the separation of technical C₈.₁₈ coconut oil fatty alcohol by distillation and which may contain less than 6% by weight of C₁₂ alcohol as an impurity, and also alkyl oligoglucosides based on technical C₉-π oxoalcohols (DP = 1 to 3) are preferred. In addition, the alkyl or alkenyl group R¹ may also be derived from primary alcohols containing 10 to 22, in particular 12 to 22 and preferably 12 to 16 carbon atoms. Typical examples are decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, brassidyl alcohol and technical mixtures thereof which may be obtained as described above. Of particular interest are the so-called cocoglucosides, which have a C₈.₁₈ alkyl group mixture derived from coconut fatty alcohols. Alkyl oligoglucosides based on hydrogenated C₁ .₁₄ coconut oil fatty alcohol having a DP of 1 to 3 are preferred.

Amphoteric surfactants

The compositions of the invention additionally may contain amphoteric or zwitterionic surfactants. Typical examples of amphoteric or zwitterionic surfactants are alkyl betaines, alkyl amidobetaines, aminopropionates, aminoglycinates, imidazolinium betaines, sulfobetaines and amphoacetates. These types of surfactants are all known compounds.

The formulations in accordance with the present preferably contain only small amounts of betaines, in particular the betaines will be present at the concentrations specified herein. Of particular interest are formulations that do not substantially contain betaines. The latter means that the formulations contain no or only some small amounts of betaines, e.g. less than about 0.5 weight-%, or even less than about 0.3 weight-%, or less than about 0.1 weight-%.

Betaines

Betaines are known surfactants, which are mainly produced by carboxyalkylation, preferably carboxymethylation, of amine compounds. The starting materials are preferably condensed with halocarboxylic acids or salts thereof, more particularly with sodium chloroacetate, one mole of salt being formed per mole of betaine. The addition of unsaturated carboxylic acids, for example acrylic acid, is also possible. Examples of suitable betaines are the carboxyalkylation products of secondary and, in particular, tertiary amines corresponding to formula (II):

I

R²-N-(CH₂)nCOOX (II)

I R⁴

in which R² stands for alkyl and/or alkenyl groups containing 6 to 22 carbon atoms, R³ stands for hydrogen or alkyl groups containing 1 to 4 carbon atoms, R⁴ stands for alkyl groups containing 1 to 4 carbon atoms, n is a number of 1 to 6 and X is an alkali metal and/or alkaline earth metal or an ammonium group, the latter including unsubstituted and substituted ammonium such as alkyl ammonium, alkanol ammonium and glucammonium. Typical examples are the carboxymethylation products of hexyl methyl amine, hexyl dimethyl amine, octyl dimethyl amine, decyl dimethyl amine, dodecyl methyl amine, dodecyl dimethyl amine, dodecyl ethyl methyl amine, C₁₂.₁₄ cocoalkyl dimethyl amine, myristyl dimethyl amine, cetyl dimethyl amine, stearyl dimethyl amine, stearyl ethyl methyl amine, oleyl dimethyl amine, C₁₆.₁₈ tallow alkyl dimethyl amine and technical mixtures thereof.

Other suitable betaines are carboxyalkylation products of amidoamines corresponding to formula (El):

R³

I

R5CO-NH-(CH₂)_m-N-(CH2)nCOOX (III)

I R⁴ in which R⁵CO is an aliphatic acyl group containing 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, m is a number from 1 to 3 and R³, R⁴, n and X have the same meaning as described above. Typical examples are reaction products of fatty acids containing 6 to 22 carbon atoms, namely caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselic acid, linoleic acid, linolenic acid, elaeostearic acid, arachic acid, gadoleic acid, behenic acid and erucic acid and technical mixtures thereof, with N, N- dimethyl aminoethyl amine, N,N-dimethyl aminopropyl amine, N,N-diethyl aminoethyl amine and N,N-diethyl aminopropyl amine which are condensed with sodium chloroacetate. It is preferred to use a condensation product of C_8-18 cocofatty acid-N,N- dimethyl aminopropyl amide with sodium chloroacetate.

Another type of betaines, which can be added to the formulations according to the invention are the imidazolines that can be represented by formula (IV):

wherein R⁶ represents an alkyl group having 5 to 21 carbon atoms, R⁷ represents a hydroxy group, a OCOR⁶- or NHCOR⁷-group and m equals 2 or 3. These substances are also known components that can be prepared, for example, by a cyclic condensation of 1 or 2 moles of fatty acids with polyvalent amines, such as, for example aminoethylethanolamine (AEEA) or diethylenetriamine. The corresponding carboxyalkylation products result in mixtures of different multiple-chain betaines. Typical examples are the condensation products of the previously mentioned fatty acids with AEEA, preferably imidazoline out off lauric acid or C₁₂.₁₄-cocofatty acids, which are subsequently converted into betaines with sodium chloracetate. Amphoalkanoates. amphodialkanoates. aminoalkanoates and imino-alkanoates Alkyl or alkenyl-amphoalkanoates or ampho-dialkanoates can more generally be represented by formula (V) :

R^aC(0)-NH-CH₂CH₂-N-CH₂CH₂-0-R

I

Alk-C(O)0- (V);

wherein: R^a represents an alkyl or alkenyl radical containing 10 to 24 carbon atoms, usually the coco or lauryl chains; each Alk represents alkylene, in particular Cι-₄alkylene, more in particular CH or

CH₂CH ;

R^b represents hydrogen (e.g. in the amphoacetates or amphopropionates) or -Alk- C(O)OM (e.g. in the amphodiacetates or amphodipropionates); and each M represents a hydrogen atom, an alkali metal or an alkaline-earth metal, or an amine or an ammonium group, the latter including unsubstituted and substituted ammonium such as alkyl ammonium, alkanol ammonium and glucammonium.

Of interest are the alkyl or alkenyl amphoacetates, alkyl or alkenyl amphodiacetates, the alkyl or alkenyl amphopropionates or the alkyl or alkenyl amphodipropionates. Of particular interest are the alkyl amphoacetates or di-acetates as well as the alkyl ampho-propionates or dipropionates, wherein the alkyl preferably is lauryl or coco.

As used herein alkyl and alkenyl refers to hydrocarbon radicals having from about 4 to about 30 carbon atoms, in particular from about 8 to about 22 carbon atoms. Alkyl or alkenyl may also be defined above in relation to the alkyl or alkenylglucosides.

Another class of useful amphoteric surfactants for use in the formulations of this invention are the alkyl or alkenyl aminoalkanoates and the alkyl or alkenyl- iminodialkanoates which can be structurally represented by the following formulae: Rc-NH-Alk-COO-M R^c-N(Alk-C00-M)₂

wherein R^c represents an alkyl or alkenyl radical, this can be a radical containing 10 to 24 carbon atoms, usually the coco or lauryl chains; M and Alk are as defined above. Of particular interest are the alkyl or alkenyl aminopropionates.

Preferred amphoteric surfactants are the amphoacetates and particularly preferred is lauroamphocetate.

Anionic co-surfactants

Typical examples of anionic surfactants, which are used as co-surfactant in the formulations of the invention are soaps, alkyl benzene- sulfonates, alkane sulfonates, olefin sulfonates, alkyl ether sulfonates, glycerol ether sulfonates, α-methyl ester sulfonates, sulfofatty acids, alkyl sulfates, fatty alcohol ether sulfates, glycerol ether sulfates, fatty acid ether sulfates, hydroxy mixed ether sulfates, monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono- and dialkyl sulfosuccinates, mono- and dialkyl sulfosuccinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and salts thereof, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, N- acyl amino acids such as, for example, acyl lactylates, acyl tartrates, acyl glutamates and acyl aspartates, alkyl oligoglucoside sulfates, protein fatty acid condensates (more particularly vegetable wheat-based products) and alkyl (ether)phosphates. Where the anionic surfactants contain polyglycol ether chains, they may have a conventional homologue distribution although they preferably have a narrow homologue distribution. Alkyl ether sulfates are preferably used as anionic co-surfactants.

Alkyl ether sulfates

Alkyl ether sulfates ("ether sulfates") are also known anionic surfactants that are industrially produced by the sulfation of fatty alcohol or oxoalcohol polyglycol ethers with sulfonic or chlorosulfonic acids (CS A) and subsequent neutralization. Ether sulfates suitable for the purposes of the invention correspond to formula (VI): R80-(CH₂CH₂0)mS0₃X (VI)

in which R is a linear or branched alkyl and/or alkenyl group containing 6 to 22 carbon atoms, n is a number of 1 to 10 and X is an alkali metal and/or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium. Typical examples are the sulfates of addition products of on average 1 to 10 and, more particularly, 2 to 5 moles of ethylene oxide onto caproic alcohol, caprylic alcohol, 2- ethyl hexyl alcohol, capric alcohol, lauryl alcohol, isotridecyl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol and brassidyl alcohol and technical mixtures thereof in the form of their sodium and/or magnesium salts. The ether sulfates may have both a conventional homologue distribution and a narrow homologue distribution. It is particularly preferred to use ether sulfates based on adducts of, on average, 2 to 3 moles of ethylene oxide with technical C₁₂-₁₄ or C₁₂-₁₈ coconut fatty alcohol fractions in the form of their sodium and/or magnesium salts.

The formulations according to the invention have a total concentration of surfactants (a) + (b) + (c) which is in the range of 0.1 to 20, in particular in the range of 1 to 15 and more in particular in the range of 5 to 13 weight-%, or in the range of 5 to 12 weight-% - relative to the total weight of the formulation.

Particular formulations according to this invention have the following composition : (a) 0.1 to 20 weight-% alkyl oligoglucosides,

(b) 0.1 to 20 weight-% amphoteric surfactants; and

(c) 0.1 to 20 weight-% anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.1 : 1 to 10 : 1, and that the quantities are completed to 100% by addition of suitable further components. Preferred are preparations with following composition :

(a) 1 to 10 weight-% alkyl oligoglucosides;

(b) 1 to 10 weight-% amphoteric surfactants; and

(c) 1 to 10 weight-% anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.5 : 1 to 5 : 1, and that the quantities are completed to 100% by addition of suitable further components.

More preferred are formulations with following composition : a) 2 to 10 weight-% alkyl oligoglucosides; b) 2 to 10 weight-% amphoteric surfactants; and c) 2 to 5 weight-% anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 2 : 1 to 3 : 1, and that the quantities are completed to 100% by addition of suitable further components.

Further preferred are formulations as defined in the previous paragraph, containing a) 2 to 8 weight-% or in particular 3 to 5 weight-% alkyl oligoglucosides, b) 2 to 5 weight-% amphoteric surfactants and c) 2 to 5 weight-% anionic co-surfactants.

In the particularly preferred preparations the surfactants' weight ratio of the alkyl glucosides to amphoteric surfactants to the anionic co-surfactants [a : b : c] is in the range of (1.0 to 1.5) : (1.0 to 1.3) : 1.

Of specific interest are any of the formulations mentioned above or herein after wherein the amphoteric surfactants are selected from the group consisting of amphoalkanoates, amphodialkanoates, aminoalkanoates, and imino alkanoates. Of further interest are any of the formulations mentioned above or hereinafter wherein the amphoteric surfactants are selected from the group consisting of alkyl or alkenyl amphoacetates, alkyl or alkenyl amphodiacetates, alkyl or alkenyl amphopropionates or alkyl or alkenyl amphodipropionates. Of still further interest are the alkyl amphoacetates or di-acetates as well as the alkyl ampho-propionates or dipropionates, wherein the alkyl moiety preferably is lauryl or coco. As used herein alkyl and alkenyl by preference refer to hydrocarbon radicals having from about 4 to about 30 carbon atoms, in particular from about 8 to about 22 carbon atoms.

The lathering formulations according to the present invention may be formulated into a variety of cleansing products such as, for example, shampoos, foam bath formulations, bath and shower gels, and any other cleansing formulations.

These formulations may also contain further auxiliary agents and additives such as mild surfactants, oil components, emulsifiers, superfatting agents, pearlizing waxes, consistency promoters, thickeners, polymers, silicone compounds, fats, waxes, lechitines, phospholipids, stabilizers, biogenic agents, deodorizers, anti-dandruff agents, film formers, swelling agents, XJV protection factors, antioxidants, hydrotropes, preservatives, insect repellents, tyrosin inhibitors, solubilizers, perfume oils, dyes and the like.

Consistency promoters and thickeners

Optional ingredients of the formulations according to the invention are consistency promoters and thickeners.

Suitable consistency promoters in particular are fatty alcohols containing 12 to 22 and preferably 16 to 18 carbon atoms and, in addition, partial glycerides. These substances are preferably used in combination with alkyl oligoglucosides and/or fatty acid-N- methyl glucamides of the same chain length and/or polyglycerol poly- 12- hydroxystearates.

Suitable thickeners are, for example, hydrophilic silica products (Aerosil®), polysaccharides, more especially xanthan gum, guar-guar, agar- agar, alginates and tyloses, carboxymethyl cellulose and hydroxyethyl cellulose, also relatively high molecular weight polyethylene glycol monoesters and diesters of fatty acids, polyacrylates (for example Carbopol® and Pemulen-types [Goodrich], Synthalens® [Sigma], Keltrol® [Kelco], Sepigel® [Seppic], Salcare® [Allied Colloids]), polyacrylamides, polymers, polyvinyl alcohol and polyvinyl pyrrolidone. Particularly suited is also bentonite, for example Bentone® Gel VS-5PC [Rheox], which is a mixture of cyclopentasiloxanc, disteardimonium hectorite und propylene carbonate. Also suited are surfactants, such as ethoxylated fatty acid glycerides, esters of fatty acids with polyols, for example pentaerythritol or trimethylol propane, narrow-range fatty alcohol ethoxylates or alkyl oligoglucosides and electrolytes, such as alkali metal or alkaline earth metal salts, in particular the halides, e.g. sodium chloride and ammonium chloride.

Preferred are polyethyleneglycol fatty acids, particularly preferred is PEG-distearate.

The quantity of consistency promoters and thickeners to be used in the formulations according to the present invention is determined by the desired viscosity of these formulations, which may be in the range of 1000 to 10,000 mPas and preferably in the range 3,000 to 6,000 mPas (Brookfield viscosimeter, spindle 4, 10 r.p.m., at +/-3° C).

Other optional ingredients

Suitable oil components that can be added are, for example, Guerbet alcohols based on fatty alcohols containing 6 to 18 and preferably 8 to 10 carbon atoms, esters of linear C₆-₂₂ fatty acids with linear C₆. ₂ fatty alcohols, esters of branched C_6-13 carboxylic acids with linear C_6-22 fatty alcohols such as, for example, myristyl myristate, myristyl palmitate, myristyl stearate, myristyl isostearate, myristyl oleate, myristyl behenate, myristyl erucate, cetyl myristate, cetyl palmitate, cetyl stearate, cetyl isostearate, cetyl oleate, cetyl behenate, cetyl erucate, stearyl myristate, stearyl palmitate, stearyl stearate, stearyl isostearate, stearyl oleate, stearyl behenate, stearyl erucate, isostearyl myristate, isostearyl palmitate, isostearyl stearate, isostearyl isostearate, isostearyl oleate, isostearyl behenate, isostearyl oleate, oleyl myristate, oleyl palmitate, oleyl stearate, oleyl isostearate, oleyl oleate, oleyl behenate, oleyl erucate, behenyl myristate, behenyl palmitate, behenyl stearate, behenyl isostearate, behenyl oleate, behenyl behenate, behenyl erucate, erucyl myristate, erucyl palmitate, erucyl stearate, erucyl isostearate, erucyl oleate, erucyl behenate and erucyl erucate. Also suitable are esters of linear C₆-₂ fatty acids with branched alcohols, more particularly 2-ethyl hexanol, esters of hydroxycarboxylic acids with linear or branched C₆. ₂ fatty alcohols, more especially Dioctyl Malate, esters of linear and/or branched fatty acids with polyhydric alcohols (for example propylene glycol, dimer diol or trimer triol) and/or Guerbet alcohols, triglycerides based on C₆.₁₀ fatty acids, liquid mono-/di-/triglyceride mixtures based on C₆-₁₈ fatty acids, esters of C₆-₂₂ fatty alcohols and/or Guerbet alcohols with aromatic carboxylic acids, more particularly benzoic acid, esters of C_2-1 dicarboxylic acids with linear or branched alcohols containing 1 to 22 carbon atoms or polyols containing 2 to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear and branched C_6-22 fatty alcohol carbonates, Guerbet carbonates, esters of benzoic acid with linear and/or branched C₆-₂₂ alcohols (for example Finsolv® TN), linear or branched, symmetrical or nonsymmetrical dialkyl ethers containing 6 to 22 carbon atoms per alkyl group, ring opening products of epoxidized fatty acid esters with polyols, silicone oils and/or aliphatic or naphthenic hydrocarbons, for example squalane, squalene or dialkyl cyclohexanes.

The addition products of ethylene oxide and/or propylene oxide with fatty alcohols, fatty acids, alkylphenols or with castor oil are known commercially available products. They are homolog mixtures of which the average degree of alkoxylation corresponds to the ratio between the quantities of ethylene oxide and/or propylene oxide and substrate with which the addition reaction is carried out. C₁₂-₁₈ fatty acid monoesters and diesters of addition products of ethylene oxide with glycerol are known as refatting agents for cosmetic formulations.

Typical examples of suitable partial glycerides are hydroxystearic acid monoglyceride, hydroxystearic acid diglyceride, isostearic acid monoglyceride, isostearic acid diglyceride, oleic acid monoglyceride, oleic acid diglyceride, ricinoleic acid monoglyceride, ricinoleic acid diglyceride, linoleic acid monoglyceride, linoleic acid diglyceride, linolenic acid monoglyceride, linolenic acid diglyceride, erucic acid monoglyceride, erucic acid diglyceride, tartaric acid monoglyceride, tartaric acid diglyceride, citric acid monoglyceride, citric acid diglyceride, malic acid monoglyceride, malic acid diglyceride and technical mixtures thereof which may still contain small quantities of triglyceri.de from the production process. Addition products of 1 to 30 and preferably 5 to 10 moles of ethylene oxide with the partial glycerides mentioned are also suitable.

Typical examples of fats are glycerides, i.e. solid or liquid (in this case often also referred to as oils) vegetable or animal products which consist essentially of mixed glycerol esters of higher fatty acids, and suitable waxes are inter alia natural waxes, such as, for example, candelilla wax, carnauba wax, japan wax, esparto grass wax, cork wax, guaruma wax, rice germ oil wax, sugarcane wax, ouricury wax, montan wax, beeswax, shellac wax, spermaceti, lanolin (wool wax), uropygial grease, ceresin, ozokerite (earth wax), petrolatum, paraffin waxes, microcrystalline waxes; chemically modified waxes (hard waxes), such as, for example, montan ester waxes, sasol waxes, hydrogenated jojoba waxes, and synthetic waxes, such as, for example, polyalkylene waxes and polyethylene glycol waxes. In addition to the fats, suitable additives are also fat-like substances, such as lecithin and phospholipids. For the person skilled in the art, the term "lecithins" means those glycerophospholipids formed from fatty acids, glycerol, phosphoric acid and choline by esterification. In the specialist field, lecithins are therefore also often referred to as phosphatidylcholines (PC). Examples of natural lecithins which may be mentioned are cephalins, which are also referred to as phosphatidic acids and are derivatives of l,2-diacyl-sn-glycerol-3-phosphoric acids. By contrast, the term "phospholipids" usually means mono- and, preferably, diesters of phosphoric acid with glycerol (glycerol phosphates), which are generally considered to be fats. In addition, sphingosines and sphingolipids are also suitable.

Suitable pearlizing waxes that can be added are, for example, alkylene glycol esters, especially ethylene glycol distearate; fatty acid alkanolamides, especially cocofatty acid diethanolamide; partial glycerides, especially stearic acid monoglyceride; esters of polybasic, optionally hydroxysubstituted carboxylic acids with fatty alcohols containing 6 to 22 carbon atoms, especially long-chain esters of tartaric acid; fatty compounds, such as for example fatty alcohols, fatty ketones, fatty aldehydes, fatty ethers and fatty carbonates which contain in all at least 24 carbon atoms, especially laurone and distearylether; fatty acids, such as stearic acid, hydroxystearic acid or behenic acid, ring opening products of olefin epoxides containing 12 to 22 carbon atoms with fatty alcohols containing 12 to 22 carbon atoms and/or polyols containing 2 to 15 carbon atoms and 2 to 10 hydroxyl groups and mixtures thereof.

The superfatting agents that can be added to the formulations may be such substances as, for example, lanolin and lecithin and polyethoxylated or acylated lanolin and lecithin derivatives, polyol fatty acid esters, monoglycerides and fatty acid alkanolamides, the latter also serving as foam stabilizers.

Suitable cationic polymers that can be added are, for example, cationic cellulose derivatives such as, for example, the quatemized hydroxyethyl cellulose obtainable from Amerchol under the name of Polymer JR 400®, cationic starch, copolymers of diallyl ammonium salts and acrylamides, quatemized vinyl pyrrolidone/vinyl imidazole polymers such as, for example, Luviquat® (BASF), condensation products of polyglycols and amines, quatemized collagen polypeptides such as, for example, Lauryldimonium Hydroxypropyl Hydrolyzed Collagen (Lamequat® L, Grϋnau), quatemized wheat polypeptides, polyethyleneimine, cationic silicone polymers such as, for example, amodimethicone, copolymers of adipic acid and dimethylaminohy- droxypropyl diethylenetriamine (Cartaretine®, Sandoz), copolymers of acrylic acid with dimethyl diallyl ammonium chloride (Merquat® 550, Chemviron), polyaminopolyamides and crosslinked water-soluble polymers thereof, cationic chitin derivatives such as, for example, quatemized chitosan, optionally in microcrystalline distribution, condensation products of dihaloalkyls, for example dibromobutane, with bis-dialkylamines, for example bis-dimethylamino-l,3-propane, cationic guar gum such as, for example, Jaguar®CBS, Jaguar®C-17, Jaguar®C-16 of Celanese, quatemized ammonium salt polymers such as, for example, Mirapol® A-15, Mirapol® AD-1, Mirapol® AZ-1 of Miranol.

Suitable anionic, zwitterionic, amphoteric and nonionic polymers that can be added are, for example, vinyl acetate/crotonic acid copolymers, vinyl pyrrolidone/vinyl acrylate copolymers, vinyl acetate/butyl maleate/isobomyl acrylate copolymers, methyl vinylether/maleic anhydride copolymers and esters thereof, uncrosslinked and polyol- crosslinked polyacrylic acids, acrylamidopropyl trimethylammonium chloride/acrylate copolymers, octylacrylamide/methyl methacrylate/tert.-butylaminoethyl methacrylate/2- hydroxypropyl methacrylate copolymers, polyvinyl pyrrolidone, vinyl pyrrolidone/vinyl acetate copolymers, vinyl pyrrolidone/dimethylaminoethyl methacrylate/vinyl caprolactam terpolymers and optionally derivatized cellulose ethers and silicones.

Suitable silicone compounds are, for example, dimethyl polysiloxanes, methylphenyl polysiloxanes, cyclic silicones and amino-, fatty acid-, alcohol-, polyether-, epoxy-, fluorine-, glucoside- and/or alkyl-modified silicone compounds which may be both liquid and resin-like at room temperature. Other suitable silicone compounds are simethicones, which are mixtures of dimethicones with an average chain length of 200 to 300 dimethylsiloxane units and hydrogenated silicates.

The formulations of the invention may further contain amounts of suitable UV protection factors, biogenic agents such as, for example, tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, deoxyribonucleic acid, retinol, bisabolol, allantoin, phytantriol, panthenol, AHA acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts and vitamin complexes, deodorants, germ inhibitors, enzyme inhibitors, odor absorbers, which are substances which are capable of absorbing and largely retaining odor-forming compounds, film formers, swelling agents such as Pemulen and alkyl-modified Carbopol types (Goodrich).

Suitable solubilizers or hydrotropes are, for example, ethanol, isopropyl alcohol or polyols.

Suitable preservatives are any of the preservatives mentioned in the European Cosmetic Directive, Annex VI, and comprise, for example, phenoxyethanol, formaldehyde solution, parabens, pentanediol or sorbic acid and the like.

Suitable perfume oils are mixtures of natural and synthetic perfumes. Natural perfumes include the extracts of blossoms (lily, lavender, rose, jasmine, neroli, ylang- ylang), stems and leaves (geranium, patchouli, petitgrain), fruits (anise, coriander, caraway, juniper), fruit peel (bergamot, lemon, orange), roots (nutmeg, angelica, celery, cardamon, costus, iris, calmus), woods (pinewood, sandalwood, guaiac wood, cedarwood, rosewood), herbs and grasses (tarragon, lemon grass, sage, thyme), needles and branches (spruce, fir, pine, dwarf pine), resins and balsams (galbanum, elemi, benzoin, myrrh, olibanum, opoponax). Animal raw materials, for example civet and beaver, may also be used. Typical synthetic perfume compounds are products of the ester, ether, aldehyde, ketone, alcohol and hydrocarbon type. Examples of perfume compounds of the ester type are benzyl acetate, phenoxyethyl isobutyrate, p-tert.butyl cyclohexylacetate, linalyl acetate, dimethyl benzyl carbinyl acetate, phenyl ethyl acetate, linalyl benzoate, benzyl formate, ethylmethyl phenyl glycinate, allyl cyclohexyl propionate, styrallyl propionate and benzyl salicylate. Ethers include, for example, benzyl ethyl ether while aldehydes include, for example, the linear alkanals containing 8 to 18 carbon atoms, citral, citronellal, citronellyloxyacetaldehyde, cyclamen aldehyde, hydroxycitronellal, lilial and bourgeonal. Examples of suitable ketones are the ionones, α-isomethylionone and methyl cedryl ketone. Suitable alcohols are anethol, citronellol, eugenol, isoeugenol, geraniol, linalool, phenylethyl alcohol and terpineol. The hydrocarbons mainly include the terpenes and balsams. However, it is preferred to use mixtures of different perfume compounds which, together, produce an agreeable fragrance. Other suitable perfume oils are essential oils of relatively low volatility which are mostly used as aroma components.

Suitable dyes are any of the substances suitable and approved for cosmetic purposes as listed.

The formulations of the present invention have a reduced content of anionic surfactants but nevertheless provide good lathering properties. Additionally, the total content of surfactants in the formulations of the invention is lower without negatively impacting their cleaning and lathering performance. This further aids to decreasing irritation and moreover is attractive from and economic point of view. The formulations of the invention are well tolerated and are particularly useful for applications on babies and sensitive skin types. The formulations specifically can be formulated into shampoos with reduced or low eye stinging. The formulations according to the invention have excellent lathering and cleansing properties and because of their mildness they are well suited for application on the skin.

The invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention thereto. All percentages relating to ingredients mentioned in these examples are weight/weight, relative to the total weight of the formulation.

Examples

Example 1

% Coco glucoside 5.0 %

Na Cocoamphoacetate 4.41 % Na laureth sulfate 4.0 %

Polyquatemium-10 0.20 % Hydroxypropyltrimonium- Hydrolyzed wheat protein 0.60 % Aqua 81.245 %

Tetrasodium EDTA (86%) 0.065 % Glycerine (100%o) 0.500 %

Phenoxyethanol 0.80 %

Methylparaben 0.165 %

Citric acid (35%) / Aqua (65%) 0.45 %

PEG 150 Distearate 0.14 % PEG -4 Rapeseedamide (100%) 0.50 %

Fragrance 0.15 %

PEG 80 Sorbitan Laurate (>70%) 0.80 %

Iodopropynyl Butylcarbamate (10%) /

PEG-4 (10%) / PEG-4 Laurate (40%) / PEG-4 Dilaurate (40%) 0.04 %

Dye 1.00 %

TOTAL 100 %

First the surfactants are mixed, whereupon a mixture of the conditioners (Polyquatemium-10 and hydrolyzed wheat) in water is added. Then the other ingredients are added in the sequence that they are listed. Example 2

Aqua 84.96 % Cocoglucoside 4.10 %

Sodium Lauroamphoacetate 3.29 %

Sodium Laureth Sulfate 2.98 %

Polyquatemium-10 0.090 %

Tetrasodium EDTA (86%) 0.065 %

Glycerine (100%) 0.500 %

Phenoxyethanol 0.80 %

Methylparaben 0.165 % Citric acid (35%) / Aqua (65%) 0.45 %

PEG 150 Distearate 0.14 %

PEG -4 Rapeseedamide (100%) 0.50 %

Fragrance 0.15 %

PEG 80 Sorbitan Laurate (>70%) 0.80 % Iodopropynyl Butylcarbamate (10%) / PEG-4 (10%) / PEG-4 Laurate (40%) /

PEG-4 Dilaurate (40%) 0.04 %

Dye 1.00 %

TOTAL 100 %

First the surfactants are mixed, whereupon the conditioner (Polyquatemium-10) is added. Then the other ingredients are added in the sequence that they are listed.

Example 3

The Trans-Epithelial Permeability (TEP) assay is used as an in vitro model for ocular irritation based on damage to the permeability barrier of the comeal epithelium. The permeability barrier is formed by tight junctions and desmosomes of the outermost cell layers.

One of the first events to occur when an irritant comes into contact with the comeal epithelium is the loss of the permeability barrier as tight junctions separate. The epithelium becomes leaky exposing the underlying stroma to the irritant and eventually cells detach. The imbibition of fluid may cause the stroma to swell and the collagen lamellae to separate, resulting in cloudiness.

Tight junctions are found in several well established epithelial cell lines including MDCK cells. A confluent monolayer of MDCK cells grown on a microporous insert exhibits high electrical resistance and does not allow the passage of sodium fluorescein across the membrane. The confluent layer of MDCK cells behaves as a functional intact epithelium. After treatment with shampoo, electrical resistance is lost and sodium fluorescein leaks across the membrane to the lower well in a dose related manner.

Method

TEP assay :

1. MDCK cells seeded into Transwell™ inserts at a density of 1 X 10⁵ cells/well

2. MDCK cells grown to confluency on the 0.4μm porous membrane of the insert over 48 hours

3. Inserts washed with HBSS and placed in a fresh 24 well plate containing lOOOμl HBSS in each well

4. 200 μl of test shampoo diluted in HBSS added to each insert

5. Monolayer exposed to test shampoo for 15 minutes.

6. Insert washed with HBSS before placing in a fresh 24 well plate containing lOOOμl in each well. 7. 200 μl of 0.02% sodium fluorescein added to each insert.

8. Amount of sodium fluorescein leaked through to the lower well measured spectrophotometrically (492nm) Modified eye test:

1. lOOμl of neat shampoo added to one rabbit eye once a day for three days

2. Eyes examined according to the Draize scoring system at lhr, 24hrs, 48hrs, 96hrs and 7 days after the first instillation

3. In vitro comeal rating based on the number of animals out of six exhibiting positive comeal reactions :

Rating Animals with opacity Description

1 0 slight

2 1 slight/moderate

3 2-3 moderate

4 4-5 moderate/severe

5 6 severe

Data Analysis Probit analysis was carried out on absorbance readings to generate an EC₅₀ value. The EC₅₀ values from two or three assays were averaged and plotted against the various components of the modified eye test :

Log EC₅₀ compared to various components of the modified eye test : PCR The number of comeal reactions out of six expressed as a percentage J&J Based on the rating described in the modified eye test.

MASC The maximum comeal score during the 7 day evaluation period for all six rabbits. Average of all in vivo runs. MASCJ The maximum conjunctival score during the 7 day evaluation period for all six rabbits. Average of all in vivo runs. MADS The maximum daily score during the 7 day evaluation period for all six rabbits. Average of all in vivo runs. Correlation of in vivo and in vitro data was done for 39 formulations:

Variable Correlation coefficient

PCR 0.81

J&J Rating 0.78 MASC 0.75

MASCJ 0.68

MADS 0.66

Prediction of comeal irritation Formulations with an EC₅₀ greater than 2% (expressed as 'TEP > 2.00') can be predicted as less than moderate irritants by the TEP. Formulations with an EC₅₀ less than 2% were predicted as moderate irritants or greater by the TEP.

Using a cut-off of 2%, 20 of 41 formulations were correctly predicted as greater than moderate irritants. 4 of the formulations were incorrectly predicted as moderate or greater irritants and 17 formulations were correctly predicted as less than moderate irritants.

Using these results the TEP assay has a positive predictive value (PV+) of 100% and a negative predictive value (PV-) of 81%.

Using the formulations of example 1 and 2 in the TEP assay method described above, an EC₅₀ greater than 2% for both formulations was found (TEP value > 2.00).

Claims

1. A lathering skin-care formulation comprising a surfactant system containing:

(a) one or more alkyl or alkenyl oligoglucosides, (b) one or more amphoteric surfactants, and

(c) one or more anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.1 : 1 to 10 : 1, and wherein the TEP value of the formulation is equal or above about 1.95.

2. A lathering skin-care formulation comprising a surfactant system containing:

(a) one or more alkyl or alkenyl oligoglucosides,

(b) one or more amphoteric surfactants, and

3. A formulation according to claim 2, wherein the total concentration of betaine surfactants does not exceed 1.5%, in particular does not exceed 1 weight-%, more in particular has substantially no betaine content.

4. A formulation according to claims 1-3, wherein the formulation contains at least about 2 weight-% or in particular 3 weight-% of one or more alkyl or alkenyl oligoglucosides.

5. A formulation according to claim 1, wherein the formulation comprises a surfactant system containing

(a) one or more alkyl or alkenyl oligoglucosides; (b) one or more amphoteric surfactants selected from the group consisting of amphoalkanoates, amphodialkanoates, aminoalkanoates, and imino alkanoates; (c) one or more anionic co-surfactants.

6. A formulation as claimed in claims 2-5, having a TEP value, which is equal or above about 1.95.

7. A formulation according to claims 1-6, wherein the total concentration of anionic surfactants is lower than 5 weight-%, relative to the total weight of the formulation.

8. A formulation according to claims 1 or 7, wherein the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co-surfactants [(a + b) : c] is such that it is in the range of 1.5 : 1 to 10 : 1.

9. A formulation according to claim 8, wherein the total concentration of surfactants (a) + (b) + (c) is in the range of 0.1 to 20, in particular in the range of 1 to 15 and more in particular in the range of 5 to 13 weight-% - relative to the total weight of the formulation.

10. A formulation according to claim 1, containing :

(a) 0.1 to 20 weight-% alkyl oligoglucosides,

(b) 0.1 to 20 weight-% amphoteric surfactants and (c) 0.1 to 20 weight-% anionic co-surfactants the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.1 : 1 to 10 : 1, and wherein the quantities are completed to 100% by addition of suitable further components.

11. A formulation according to claim 10 containing :

(a) 1 to 10 weight-% alkyl oligoglucosides;

(b) 1 to 10 weight-% amphoteric surfactants; and

(c) 1 to 10 weight-% anionic co-surfactants; the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 1.5 : 1 to 5 : 1, and wherein the quantities are completed to 100% by addition of suitable further components.

12. A formulation according to claim 11 containing :

(a) 2 to 10 weight-% alkyl oligoglucosides,

(b) 2 to 10 weight-% amphoteric surfactants and (c) 2 to 5 weight-% anionic co-surfactants the weight ratio of the alkyl glucosides and amphoteric surfactants to the anionic co- surfactants [(a + b) : c] being such that it is in the range of 2 : 1 to 3 : 1, and wherein the quantities are completed to 100% by addition of suitable further components.

13. A formulation according to claim 12 containing

(a) 5 to 10 weight-% alkyl oligoglucosides,

(b) 5 to 10 weight-% amphoteric surfactants and

(c) 2 to 5 weight-% anionic co-surfactants and wherein the surfactants' weight ratio of the alkyl glucosides to amphoteric surfactants to the anionic co-surfactants [a : b : c] is in the range of (1.0 to 1.5) : (1.0 to 1.3) : 1.

14. A formulation according to any of claims 1 - 13, wherein wherein the amphoteric surfactants are selected from the group consisting of amphoalkanoates, amphodialkanoates, aminoalkanoates, and imino-alkanoates.

15. A formulation according to any of claims 1 - 13, wherein wherein the amphoteric surfactants are selected from the group consisting of alkyl or alkenyl amphoacetates, alkyl or alkenyl amphodiacetates, alkyl or alkenyl amphopropionates or alkyl or alkenyl amphodipropionates.

16. A formulation according to any of claims 1 - 13, wherein wherein the amphoteric surfactants are selected from the group consisting of alkyl amphoacetates or di-acetates as well as alkyl ampho-propionates or dipropionates,

17. A formulation according to claim 16, wherein wherein the alkyl is lauryl or coco.