Synergistic mixtures of aromatic alcohols and derivatives thereof and tropolone (derivatives)

The present invention relates to the field of antimicrobial active compounds, and in particular certain mixtures, formulations and foodstuffs comprising certain compounds (alcohols, ethers, esters, acids, corresponding salts and solvates) of a formula (I) (in this context, see below) and at least one tropolone (derivative) of the formula (II) (in this context, see below) and to products comprising such mixtures in an antimicrobially active amount.

The invention also relates to certain uses and processes in which the mixtures according to the invention are employed.

In the cosmetics and pharmaceutical and in the foodstuffs industry there is a constant need for agents having antimicrobial properties, in particular for the preservation of products which are otherwise perishable (such as e.g. cosmetics, pharmaceutical products or foodstuffs), but also for direct cosmetic or therapeutic treatment of microorganisms which can have an adverse influence on the human

or animal body. Reference may be made by way of example to microorganisms which can cause body odour, acne, mycoses or the like.

In the technical fields referred to a large number of antimicrobial active compounds are indeed already employed, but alternatives nevertheless continue to be sought, in order to be able to perform targeted specific treatments and/or reduce side effects. In this context, however, in the search for alternative agents having an antimicrobial and in particular preserving action it is to be noted that the substances used in the cosmetics, pharmaceutical and/or foodstuffs field must be

- toxicologically acceptable,

readily tolerated by the skin,

stable (in particular in the conventional cosmetic and/or pharmaceutical formulations),

largely and preferably completely odourless and

- inexpensive to prepare (i.e. employing standard processes and/or starting from standard precursors).

The search for suitable (active) substances which have one or more of the properties mentioned to an adequate extent is made difficult for the person skilled in the art in that there is no clear dependency between the chemical structure of a substance on the one hand and its biological activity against certain microorganisms (germs) and its stability on the other hand. Furthermore, there is no predictable connection between the antimicrobial action, the toxicological acceptability, the skin tolerability and the stability of a substance.

According to a first aspect, the present invention relates to an antimicrobial mix- ture comprising or consisting of:

(a) one or more compounds of the formula (I)

their salts or solvates,

wherein R ¹ and R ² in each case independently of one another are chosen from the group consisting of: H, OH, F, Cl, Br and I,

and wherein X in each case denotes:

(CH ₂ )m where m = 1 , 2 or 3

or

⁰ -(- ^CH rJτr

where n = 1 , 2 or 3

or

0-CH ₂ - CH(R3)

where R ^J = CH ₃ or CH ₂ OH

CH; CH, or

where p = 1 or 2,

wherein in the compound(s) of the formula I

a primary alcohol function CH ₂ OH is optionally replaced by a radical which is chosen from the group consisting of CH ₂ OR ⁴ , COOH and COOR ⁴

and/or

a secondary alcohol function CHOH is optionally replaced by the radical CHOR ⁴ ,

wherein each R ⁴ denotes an aliphatic or aromatic radical, independently of the meaning of further radicals,

and

(b) one, two or more compounds chosen from the group consisting of the tropolones of the formula (II)

wherein the substituents R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ independently of one another have the following meaning:

H;

linear or branched, saturated or unsaturated, aliphatic hydrocarbon radical having up to 30 C atoms;

OH;

OR ¹⁰ , wherein R ¹⁰ is a linear or branched, saturated or unsaturated, aliphatic hydrocarbon radical having up to 30 C atoms;

COOH;

COOR ¹¹ , wherein R ¹¹ is a linear or branched, saturated or unsaturated, aliphatic hydrocarbon radical having up to 30 C atoms;

NO ₂ ,

NH ₂ ,

F, Cl, Br, I,

If X has the meaning (CH ₂ ) _mj the compounds benzyl alcohol (m=1) and 2- phenylethyl alcohol (m=2) are preferred.

°-(- ^CH -2 / n

If X has the meaning , the compounds 2-phenoxyethanol

(n=2) and 3-phenoxypropanol (n=3) are preferred.

Q Ql^ CH(R^

If X has the meaning ² , the compounds 1 -phenoxy-propan-2- ol (R ³ =CH ₃ ) and 3-phenoxy-propane-1,2-diol (R ³ =CH ₂ OH) result. The two compounds mentioned are preferred for use in an antimicrobial mixture according to the invention.

( CH; -CH,

If X has the meaning , the compounds benzyloxyme- thanol (p=1) and (benzyloxymethoxy)-methanol (p=2) result. The two compounds are preferred for use in antimicrobial mixtures according to the invention.

The preferred compounds of the formula (I) are shown once again below, the particular structural formulae assigned containing no indications of enantiomers which may be preferred.

Benzyl alcohol (CARN: 100-51-6)

-Phenylethyl alcohol (CARN: 60-12-8),

-Phenoxyethanol (CARN: 122-99-6),

-Phenoxypropanol (CARN: 6180-61-6),

-Phenoxy-propan-2-ol (CARN: 770-35-4);

3-Phenoxy-propane-1.2-diol (CARN: 538-43-2),

Benzyloxymethanol (CARN: 14548-60-8)

(Benzyloxymethoxy)-methanol (CARN: 35445-70-6).

The use of 2-phenoxyethanol is particularly preferred.

It has already been indicated that instead of the alcohols of the formula I reproduced above by their structural formula, certain derivatives which are derived from the said alcohols by optionally replacing a primary alcohol function CH ₂ OH by a radical which is chosen from the group consisting of CH ₂ OR ⁴ , COOH and COOR ⁴ and/or a optionally replacing a secondary alcohol function CHOH by the radical CHOR ⁴ , wherein each R ⁴ denotes an aliphatic or aromatic radical, independently of the meaning of further radicals, can be employed in an antimicrobial mixture according to the invention.

This possibility of the (alternative or additional) use of derivatives (ether, carbox- ylic acid or ester) relates in particular to the eight alcohols characterized above as preferred. Instead of the said alcohols, the corresponding ethers, car boxy lie acids or esters can thus also be employed.

Alternatively or additionally, the corresponding salts or solvates of the carboxylic acids can also be employed.

In the functional groups CH ₂ OR ⁴ and COOR ⁴ of the derivatives, R ⁴ preferably denotes a saturated or unsaturated, branched or unbranched radical having 1, 2, 3, 4 or 5 C atoms or an optionally substituted phenyl or benzyl radical.

In the mixtures according to the invention, the constituents (a) and (b) in the mixture are preferably adjusted such that their antimicrobial action is intensified synergistically.

Compounds which are preferred for use as constituent (b) in antimicrobial mixtures according to the invention are:

tropolone (formula (II): R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ = H), alpha-thujaplicin (formula (II): R ⁵ = iso-propyl, R ⁶ , R ⁷ , R ⁸ , R ⁹ = H), beta-thujaplicin (formula (II): R ⁶ = iso-propyl, R ⁵ , R ⁷ , R ⁸ , R ⁹ = H) gamma-thujaplicin (formula (II): R ⁷ = iso-propyl, R ⁵ , R ⁶ , R ⁸ , R ⁹ = H)

or a mixture of these compounds.

The structural formula of the compound tropolone (CAS No.: 533-75-5; 2,4,6- cycloheptatrien-1-one, 2-hydroxy), which is particularly preferred for use in a mixture according to the invention, is:

The invention is based on the surprising finding that the mixtures according to the invention show a synergistically intensified antimicrobial effect at least against selected germs, in particular against Aspergillus niger, a mould which can be combated only with great difficulty, and also against other germs.

In particular, it has been found that the mixtures according to the invention can be used outstandingly as an antimicrobial active compound mixture, in particular for preserving otherwise perishable articles (see above).

Although persons skilled in the art have already addressed the antimicrobial properties of aromatic alcohols, such as e.g. benzyl alcohol, 2-phenylethyl alco- hoi, 2-phenoxyethanol, 3-phenoxypropanol, 1-phenoxy-propan-2-ol, 3-phenoxy- propane-1,2-diol, benzyloxymethanol and (benzyloxymethoxy)-methanol, and of tropolone and tropolone derivatives extensively, there has hitherto been no indication that the mixtures according to the invention of such compounds have a significantly improved antimicrobial action (at least against selected germs) in the individual case.

The antimicrobial action of tropolone and tropolone derivatives is known e.g. from Antimicrob. Agents Chemother, vol. 7(5), 500-506 (1975). However, studies of a synergistically intensified activity against Aspergillus niger of a combination of tropolone with the aromatic alcohols, acids, their salts and solvates and ester and ethers to be employed according to the invention are not disclosed in any of these publications.

The antimicrobial action of benzyl alcohol, 2-phenoxyethanol and further aromatic alcohols to be employed according to the invention is described in detail e.g. in "Handbuch der Konservierungsmittel [Preservatives Handbook]" (ed.: Fach- gruppe Konservierung und Betriebshygiene der Deutschen Gesellschaft fur wissenschaftliche und angewandte Kosmetik e.V (DGK); Verlag fur chemische Industrie, H.Ziolkowsky GmbH, D-86150 Augsburg; ISBN 3 87846 171 2). However, studies of a synergistically intensified activity against Aspergillus niger in

combination with tropolone or a tropolone derivative are disclosed neither in this nor in further publications.

The aromatic alcohols to be employed according to the invention usually per se have only a deficient action, for example, against moulds such as Aspergillus niger. In respect of individual aromatic alcohols, a gap in the activity on moulds (e.g. the "problem germ" Aspergillus niger) is thus to be recorded. High use concentrations of individual aromatic alcohols have therefore hitherto been necessary for complete inhibition of moulds.

It was therefore particularly surprising that the mixtures according to the invention show a highly synergistic activity, and in the treatment of Aspergillus niger are significantly superior to

individually dosed tropolones or tropolone derivatives of the formula (II) and mixtures of tropolone (derivatives) of the formula (II) or

- individually dosed compounds of the formula (I), in particular individually dosed aromatic alcohols, such as e.g. benzyl alcohol, 2- phenylethyl alcohol,

2-phenoxyethanol, 3-phenoxypropanol, 1-phenoxy-propan-2-ol, 3-phenoxy- propane-1,2-diol, benzyloxymethanol and (benzyloxymethoxy)-methanol and mixtures of these compounds

at the same concentration, in particular in respect of the reduction in germ count and the speed of the reduction in germ count.

On the basis of the particularly significant intensification in the action of their constituents, mixtures according to the invention are suitable in particular for combating Aspergillus niger even at a low dosage of the mixture according to the invention.

For the preparation of effective mixtures according to the invention which cause a particularly rapid reduction in the Aspergillus niger germ count, it is sufficient to

mix one mixture constituent (a), such as benzyl alcohol, 2-phenylethyl alcohol, 2- phenoxyethanol, 3-phenoxypropanol, 1-phenoxy-propan-2-ol, 3-phenoxy- propane-1,2-diol, benzyloxymethanol and/or (benzyloxymethoxy)-methanol, with a small amount of constituent (b), i.e. one, two or more tropolones of the formula (II), for example an amount of (b) in the range of 0.001 - 10 wt.%, preferably only 0.5 - 4 wt.%, based on the amount of constituent (a). If an amount of 0.5 wt.% e.g. of 2-phenoxyethanol is employed, this corresponds e.g. to an amount of tropolone(s) of just about 0.005 wt.%, in each case based on the total weight of the end product.

Based on the total weight of constituents (a) and (b) to be employed according to the invention, the content of constituent (a) is preferably in the range of from 80 to 99.99 wt.%, but preferably in the range of 94 - 99.5 wt.%.

The antimicrobial mixtures according to the invention are suitable for preservation and antimicrobial treatment of perishable products, such as e.g. cosmetic prod- ucts, pharmaceutical products or foods (foodstuffs).

A cosmetic or pharmaceutical formulation according to the invention or a foodstuff according to the invention comprises

a mixture which is antimicrobial according to the invention and comprises or consists of constituents (a) and (b) as stated above and

- further conventional constituents,

the total amount of constituents (a) and (b) being in the range of from 0.01 to 10 wt.%, based on the total weight of the formulation or of the foodstuff.

For the preparation of such a formulation or such a foodstuff, the corresponding (conventionally otherwise perishable) product is brought into contact with an antimicrobially active amount, preferably an amount which is active against Aspergillus niger, of an antimicrobial mixture according to the invention.

On the basis of their synergistically intensified antimicrobial activity, however, the mixtures according to the invention can also be employed

(a) for the cosmetic treatment of microorganisms which cause body odour,

(b) for the cosmetic treatment of microorganisms which cause acne,

(c) for the cosmetic treatment of microorganisms which cause mycoses and

(d) for the treatment of microorganisms on or in inanimate matter.

On the basis of the synergistic action of constituents (a) and (b) in an antimicro- bial mixture or formulation according to the invention or a corresponding foodstuff, an adequate antimicrobial activity can already be achieved if the amount of constituent (a) and/or the amount of constituent (b) in each case considered in itself is not antimicrobially active. However, the total amount of constituents (a) and (b) is then antimicrobially active.

The present invention also relates to the use of an antimicrobial mixture according to the invention as an antimicrobial active compound mixture. In this context, that stated above applies accordingly in respect of the compounds of constituents (a) and (b) which are preferably to be employed.

The mixtures according to the invention display their synergistically intensified antimicrobial action against a large number of Gram-positive bacteria, Gram- negative bacteria, moulds and yeasts, which in particular renders possible preservation and antimicrobial treatment of a large number of cosmetic formulations. A particularly good action exists against Gram-negative bacteria, such as Escherichia coli and Pseudomonas aeruginosa, against yeasts, such as Candida albicans, and precisely - as already mentioned - against fungi, such as Aspergillus niger. The very good activity of the mixtures according to the invention

against Aspergillus niger, a mould which can be combated only with great difficulty, is to be regarded as particularly advantageous here.

The present invention furthermore relates to corresponding methods for the cosmetic and/or therapeutic treatment of germs, in particular on the human body, and in particular especially of (i) microorganisms which cause body odour, (ii) microorganisms which cause acne and/or (iii) microorganisms which cause mycoses, comprising topical application of an antimicrobially active amount of a mixture according to the invention. The contents of the said constituents (a) and (b) of the mixtures are therefore preferably adjusted such that their antimicrobial action is intensified synergistically.

Preferred embodiments of the methods according to the invention correspond to the preferred embodiments of the use according to the invention which are explained above.

The human skin is populated by a large number of various microorganisms, which include the microorganisms already mentioned above, as well as others. Most of these microorganisms are not pathogenic and are irrelevant to the physiological state of the skin and to the odour thereof. On the other hand, others can influence the healthy state of the skin decisively.

As our own studies have now shown, the synergistically active mixtures accord- ing to the invention have a good action against Staphylococcus epidermidis,

Corynebacterium xerosis, Brevibacterium epidermidis, Propionibacterium acnes and against Trichophyton and Epidermophyton species, so that they can be employed as agents for the treatment of (combating) underarm and foot odour or body odour generally, as agents for combating acne, as antidandruff agents and for the treatment of mycoses (in particular dermatomycoses).

In the context of the present text, "treatment" is understood here as meaning any form of influencing of the microorganisms in question in which the multiplication of these microorganisms is inhibited and/or the microorganisms are killed.

The use concentration of a mixture according to the invention (which is preferably in a preferred embodiment) when used as a preservative or antimicrobial active compound in a foodstuff or a cosmetic or pharmaceutical formulation is preferably in the range of from 0.01 to 10 wt.%, but particularly preferably in the range of from 0.05 to 5 wt.%, in each case based on the total weight of the foodstuff or the formulation. The foodstuff and formulation additionally comprise conventional further constituents, in this context see below. The particular content of constituents (a) and/or (b) to be used according to the invention in mixtures according to the invention can be below the amount regarded as antimicrobially active in itself if the total amount of these substances which is present is sufficiently high to achieve an antimicrobial action of the total mixture. This applies in particular to the action against Aspergillus niger.

In a preferred method according to the invention for the cosmetic and/or therapeutic treatment of (i) microorganisms which cause body odour, (ii) microorgan- isms which cause acne and/or (iii) microorganisms which cause mycoses, the use concentration of the synergistically active mixtures according to the invention is also in the range between 0.01 and 10 wt.%, and particularly preferably in the range between 0.05 and 5 wt.%, in each case based on the total weight of the cosmetic or pharmaceutical product which comprises the mixture.

The synergistically active mixtures can be employed here (a) prophylactically or (b) as required.

The concentration of the amount of active compound to be applied e.g. daily varies and depends on the physiological state of the subject and individual- specific parameters, such as age or body weight. The synergistically active mix- tures according to the invention can be employed either by themselves or in combination with further antimicrobially active substances.

Further uses/methods and mixtures/compositions according to the invention can be found in the following statements and the attached patent claims.

Compositions which comprise a mixture according to the invention are, especially if they are employed against germs which cause body odour, as a rule applied topically in the form of solutions, creams, lotions, gels, sprays or the like. For other purposes, an oral (tablets, capsules, powders, drops), intravenous, in- traocular, intraperitoneal or intramuscular administration or an administration in the form of an impregnated dressing is appropriate in some cases.

The mixtures according to the invention can be incorporated without difficulties into the usual cosmetic and/or dermatological formulations, such as, inter alia, pump sprays, aerosol sprays, creams, ointments, tinctures, lotions, nail care products (e.g. nail varnishes, nail varnish removers, nail balsams) and the like. It is also possible here, and in some cases advantageous, to combine the synergistic mixtures according to the invention with further active compounds, for example with other antimicrobially, antimycotically or antivirally active substances. The cosmetic and/or dermatological/keratological formulations comprising the syner- gistic mixtures according to the invention can otherwise have the conventional composition here and serve for the treatment of skin and/or hair in the sense of a dermatological treatment or a treatment in the sense of care cosmetics. However, they can also be employed in make-up products in decorative cosmetics.

If the mixtures according to the invention are employed as active compounds for preserving organic material, one or more further preservatives can advantageously additionally be employed as constituent(s) (c). Preservatives which are preferably chosen here are those such as 2,4-hexadienoic acid (sorbic acid) and its salts, formaldehyde and paraformaldehyde, 2-hydroxybiphenyl ether and its salts, 2-zinc-sulfidopyridine N-oxide, inorganic sulfites and bisulfites, sodium iodate, chlorobutanolum, 4-ethylmercury-(ll)5-amino-1,3-bis(2-hydroxybenzoic acid), its salts and esters, dehydracetic acid, formic acid, 1,6-bis(4-amidino-2- bromophenoxy)-n-hexane and its salts, the sodium salt of ethyl mercury-(l I)- thiosalicylic acid, phenylmercury and its salts, 10-undecylenic acid and its salts, 5-amino-1 ,3-bis(2-ethylhexyl)-5-methyl-hexahydropyrimidine, 5-bromo-5-nitro- 1 ,3-dioxane, 2-bromo-2-nitro-1,3-propanediol, N-(4-chlorophenyl)-N'-(3,4- dichlorophenyl)-urea, 4-chloro-m-cresol, 2,4,4'-trichloro-2'-hydroxy-diphenyl

ether, 4-chloro-3,5-dimethylphenol _J 1 , 1 '-methylene-bis(3-(1 -hydroxymethyl-2,4- dioximidazolidin-5-yl)urea), poly-(hexamethylenediguanide) hydrochloride, hexamethylenetetramine, 1 -(3-chloroallyl)-3,5,7-triaza-1 -azonia-adamantane chloride, 1 -(4-chlorophenoxy)-1 -(1 H-imidazol-1 -yl)-3,3-dimethyl-2-butanone, 1 ,3- bis-(hydroxymethyl)-5,5-dimethyl-2,4-imidazolidinedione, Octopirox, 1 ,2-dibromo- 2,4-dicyanobutane, benzethonium chloride, 2,2'-methylene-bis(6-bromo-4- chlorophenol), bromochlorophene, mixture of 5-chloro-2-methyl-3(2H)- isothiazolinone and 2-methyl-3(2H)-isothiazolinone with magnesium chloride and magnesium nitrate, 2-benzyl-4-chlorophenol, 3-(4-Chlorphenoxy)-1,2-propanediol (Chlorphenesin), 2-chloroacetamide, chlorhexidine, chlorhexidine acetate, chlor- hexidine gluconate, chlorhexidine hydrochloride, N-alkyl(Ci ₂ -C ₂₂ )trimethyl- ammonium bromide and chloride, 4,4-dimethyl-1,3-oxazolidine, N- hydroxymethyl-N-(1 ,3-di(hydroxymethyl)-2,5-dioxoimidazolidin-4-yl)-N'-hydroxy- methylurea, 1,6-bis(4-amidino-phenoxy)-n-hexane and its salts, glutaraldehyde, 5-ethyl-1 -aza-3,7-dioxabicyclo(3.3.0)octane, 3-(4-chlorophenoxy)-1 ,2- propanediol, hyamines, alkyl-(C ₈ -Ci ₈ )-dimethyl-benzyl-ammonium chloride, alkyl- (C ₈ -Ci ₈ )-dimethyl-benzylammonium bromide, alkyl-(C ₈ -Ci ₈ )-dimethyl-benzyl- ammonium saccharinate, benzyl hemiformal, 3-iodo-2-propynyl butylcarbamate, sodium hydroxymethyl-aminoacetate or sodium hydroxymethyl-aminoacetate, imidazolidinylurea, diazolidinylurea, sodium hydroxymethylglycinate, chlorphenesin, DMDM hydantoin, methylchloroisothiazolinone and methylisothiazolinones as well as certain 1,2-alkanediols.

Combinations with one or more branched or unbranched 1 ,2-alkanediols having 6 to 12 carbon atoms are preferred in particular. Particularly preferred combinations are those with:

1 ,2-hexanediol or

1 ,2-octanediol or

1 ,2-decanediol or

a mixture of 1 ,2-hexanediol and 1 ,2-octanediol or

a mixture of 1 ,2-hexanediol and 1 ,2-decanediol or

a mixture of 1,2-octanediol and 1 ,2-decanediol or

a mixture of 1,2-hexanediol, 1,2-octanediol and 1 ,2-decanediol.

Such mixtures which, in addition to constituents (a) and (b), also comprise one or more of the diols mentioned, often have an activity which is particularly intensified synergistically.

If the mixtures according to the invention are to be employed chiefly for inhibition of the growth of undesirable microorganisms on or in animal organisms, a combi- nation with one or more further antibacterial or antimycotic active substances (as additional constituent(s) (c)is also advantageous here in some cases. In this respect, further active compounds which are worth mentioning, in addition to the large group of conventional antibiotics, are, in particular, the products relevant for cosmetics, such as (triclosan, climbazole, octoxyglycerol (ethylhexyl glycerol, Sensiva SC50), Octopirox (1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2(1H)- pyridone, 2-aminoethanol), chitosan, totarol, famesol, geranylacetol, glycerol monolaurate, arylalkyl alcohols, such as e.g. 4-methyl-4-phenyl-2-pentanols (DE 101 43 434, in particular 4-methyl-4-phenyl-2-pentanol), muguet alcohol (2,2- dimethyl-3-phenylpropanol), other arylalkyl alcohols (e.g. as disclosed in DE 44 47 361 , DE 103 30 697, US 4,110,430 or EP 1 157 687), essential oils with antimicrobial properties and isolates from essential oils with antimicrobial properties like e.g. thymol or eugenol, perfume oils or single aroma chemicals with antimicrobial activity, polyglycerol esters, such as e.g. polyglyceryl 3-caprylates, or combinations of the substances mentioned, which are employed, inter alia, against underarm odour, foot odour or dandruff formation.

The mixtures according to the invention can advantageously be combined, in particular in cosmetic formulations, with further conventional constituents, such as, for example:

Further preservatives, further antimicrobial agents, such as e.g. further antibacte- rial agents or fungicides, abrasives, antiacne agents, agents against ageing of the skin, anticellulitis agents, antidandruff agents, antiinflammatory agents, irritation-preventing agents, irritation-inhibiting agents, antioxidants, astringents, perspiration-inhibiting agents, antiseptic agents, antistatics, binders, buffers, carrier materials, chelating agents, cell stimulants, cleansing agents, care agents, depilatory agents, surface-active substances, deodorizing agents, antiperspirants, softeners, emulsifiers, enzymes, essential oils, fibres, film- forming agents, fixatives, foam-forming agents, foam stabilizers, substances for preventing foaming, foam boosters, gelling agents, gel-forming agents, hair care agents, hair-setting agents, hair-straightening agents, moisture-donating agents, moisturizing substances, moisture-retaining substances, bleaching agents, strengthening agents, stain-removing agents, optically brightening agents, impregnating agents, dirt-repellent agents, friction-reducing agents, lubricants, moisturizing creams, ointments, opacifying agents, plasticizing agents, covering agents, polish, gloss agents, polymers, powders, proteins, re-oiling agents, abrading agents, silicones, skin-soothing agents, skin-cleansing agents, skin care agents, skin-healing agents, skin-lightening agents, skin-protecting agents, skin- softening agents, cooling agents, skin-cooling agents, warming agents, skin- warming agents, stabilizers, UV-absorbing agents, UV filters, detergents, fabric conditioning agents, suspending agents, skin-tanning agents, thickeners, vitamins, oils, waxes, fats, phospholipids, saturated fatty acids, mono- or polyunsaturated fatty acids, α-hydroxy acids, polyhydroxy-fatty acids, liquefiers, dyestuffs, colour-protecting agents, pigments, anticorrosives, aromas, flavouring substances, odoriferous substances, polyols, surfactants, electrolytes, organic solvents or silicone derivatives.

The mixtures according to the invention can moreover also particularly advantageously be employed in combination with perspiration-inhibiting active com-

pounds (antiperspirants) for combating body odour. Perspiration-inhibiting active compounds which are employed are, above all, aluminium salts, such as aluminium chloride, aluminium hydrochloride, nitrate, sulfate, acetate etc. In addition, however, the use of compounds of zinc, magnesium and zirconium may also be advantageous. For use in cosmetic and dermatological antiperspirants, the aluminium salts and - to a somewhat lesser extent - aluminium/zirconium salt combinations have essentially proved suitable. The aluminium hydroxychlorides which are partly neutralized and therefore tolerated better by the skin, but not quite so active, are additionally worth mentioning.

If the mixtures according to the invention are to be employed for antimicrobial treatment of a surface (e.g. of a human or animal body), a combination with (metal) chelators is advantageous in some cases. (Metal) chelators which are preferably to be employed here are, inter alia, α-hydroxy fatty acids, phytic acid, lactoferrin, α-hydroxy acids, such as, inter alia, citric acid, ascorbic acid, lactic acid and malic acid, and humic acids, bile acids, bile extracts, bilirubin, biliverdin or EDTA, EGTA and derivatives thereof.

For use, the cosmetic and/or dermatologically active mixtures according to the invention are applied to the skin and/or hair in a sufficient amount in the conventional manner for cosmetics and dermatics. In this context, cosmetic and derma- tological formulations which comprise a mixture according to the invention and additionally act as sunscreen compositions offer particular advantages. These formulations advantageously comprise at least one UVA filter and/or at least one UVB filter and/or at least one inorganic pigment. In this context, the formulations can be in various forms such as are conventionally employed e.g. for sunscreen formulations. They can thus be e.g. a solution, an emulsion of the water-in-oil (W/O) type or of the oil-in-water (ONSI) type or a multiple emulsion, for example of the water-in-oil-in-water (W/O/W) type, a gel, a hydrodispersion, a solid stick or also an aerosol.

As mentioned, formulations which comprise a mixture according to the invention can advantageously be combined with substances which absorb UV radiation,

the total amount of the filter substances being e.g. 0.01 wt.% to 40 wt.%, preferably 0.1 % to 10 wt.%, in particular 1.0 to 5.0 wt.%, based on the total weight of the formulations, in order to provide cosmetic formulations which protect the hair or skin from ultraviolet radiation.

A high content of care substances is regularly advantageous in formulations for topical prophylactic or cosmetic treatment of the skin comprising mixtures according to the invention. According to a preferred embodiment, the compositions comprise one or more animal and/or plant fats and oils having care properties, such as olive oil, sunflower oil, refined soya oil, palm oil, sesame oil, rapeseed oil, almond oil, borage oil, evening primrose oil, coconut oil, shea butter, jojoba oil, sperm oil, beef tallow, neat's foot oil and lard, and optionally further care constituents, such as, for example, fatty alcohols having 8-30 C atoms.

Care substances which can be combined in an outstanding manner with the synergistic mixtures according to the invention moreover also include

- ceramides, where ceramides are understood as meaning N- acylsphingosins (fatty acid amides of sphingosin) or synthetic analogues of such lipids (so-called pseudo-ceramides), which significantly improve the water retention capacity of the stratum corneum.

phospholipids, for example soya lecithin, egg lecithin and cephalins

- vaseline, paraffin oils and silicone oils; the latter include, inter alia, dialkyl- and alkylarylsiloxanes, such as dimethylpolysiloxane and methyl p he ny I- polysiloxane, as well as alkoxylated and quaternized derivatives thereof.

Cosmetic formulations which comprise mixtures according to the invention can also comprise antioxidants, it being possible for all the antioxidants which are suitable or usual for cosmetic and/or dermatological uses to be used.

Cosmetic formulations which comprise mixtures according to the invention can also comprise vitamins and vitamin precursors, it being possible for all the vitamins and vitamin precursors which are suitable or usual for cosmetic and/or dermatological uses to be used. There are worth mentioning here, in particular, vitamins and vitamin precursors, such as tocopherols, vitamin A, niacin acid and niacinamide, further vitamins of the B complex, in particular biotin, and vitamin C and panthenol and derivatives thereof, in particular the esters and ethers of panthenol and cationically derivatized panthenols, such as e.g. panthenol triacetate, panthenol monoethyl ether and the monoacetate thereof and cationic pan- thenol derivatives.

Cosmetic formulations which comprise mixtures according to the invention can also comprise antiinflammatory or redness- or itching-alleviating active compounds. All the antiinflammatory or redness- and itching-alleviating active compounds which are suitable or usual for cosmetic and/or dermatological uses can be used here.

Cosmetic formulations which comprise mixtures according to the invention can also comprise active compounds having a skin-lightening or skin-tanning action. According to the invention, all the skin-lightening or skin-tanning active compounds which are suitable or usual for cosmetic and/or dermatological uses can be used here.

Cosmetic formulations which comprise mixtures according to the invention can also comprise anionic, cationic, nonionic and/or amphoteric surfactants, especially if crystalline or microcrγstalline solids, for example inorganic micropigments, are to be incorporated into the formulations.

The invention is explained in more detail in the following with the aid of an example. Unless stated otherwise, the data relate to the weight.

Example 1 : Comparison of adequate preservation of cosmetic formulations comprising 2-phenoxyethanol (product A, not according to the invention), tropolone

(product B, not according to the invention) and a mixture of 2-phenoxyethanol and tropolone (product C, according to the invention)

Testing for adequate preservation was carried out in accordance with the European Pharmacopoeia.

Testing thus comprises contamination of the formulation, if possible in its final condition, with a prescribed inoculum of suitable microorganisms, storage of the inoculated formulation at a certain temperature, removal of samples from the container at certain intervals of time and determination of the number of microorganisms in the samples removed in this way. The preserving properties are adequate if, under the conditions of the test, a clear reduction or, where appropriate, no increase in the germ count results in the inoculated formulations after the prescribed times at the prescribed temperatures. Experimental details of the test procedure are described in the European Pharmacopoeia (ISBN 3-7692- 2768-9; Supplement 2001 to the 3rd Edition, page 421-422, chapter 5.1.3).

Test germs:

The following microorganism strains were used for the tests for adequate preservation:

A: Escherichia coli ATCC 8739

B: Pseudomonas aeruginosa ATCC 90270

C: Staphylococcus aureus ATCC 6538

D: Candida albicans ATCC 10231

E: Aspergillus niger ATCC 16404

The initial germ count (CFU/g; "0 value") was in the range of from 220,000 to 280,000 in the various test series.

Formulation:

For the tests for adequate preservation, a defined amount of the active compound combination according to the invention (product C) was incorporated into an C7W emulsion. For comparison purposes, the comparison products (product A and B) were incorporated into separate O/W emulsions.

Table 1 : Formulations with products A, B and C:

pH: 5,5

Result:

The results of the preservative stress tests for Aspergillus niger for the active compound combinations investigated, comprising the mixture according to the invention (product C) or the comparison systems (products A and B), clearly show a synergistic effect of the mixture according to the invention (product C). In the case of Aspergillus niger, a germ which is particularly problematic in respect of preservation of industrial products, it was possible to reduce the germ count to 0 within 7 days by using the mixture according to the invention. By using the mixture according to the invention (product C), it was already possible to reduce the number of colony-forming units from 220,000 to 200 after 2 days (Table 2). In contrast, the active compound contained in product A (2 -phenoxyethanol) in a dosage of 1.0 wt.% for comparison purposes rendered possible no such significant reduction in the number of colony-forming units (CFU after 2 days: 113,000) in Aspergillus niger, which also applies to product B (tropolone, dosage: 0.01 %; CFU after 2 days: 95,000). This test series thus shows by way of example that the active compound mixtures according to the invention have an action which is significantly improved synergistically compared with products A (2- phenoxyethanol) and B (tropolone).

Table 2: Testing for adequate preservation for product A (comprising 1 % phenoxyethanol), for product B (comprising 0.01 % tropolone) and for product C (mixture according to the invention comprising 0.05 % phenoxyethanol and 0.005 % tropolone).

The calculation of the SI value for treatment of Aspergillus niger with a mixture of phenoxyethanol and tropolone after an incubation phase of 2 days is shown below by way of example (Table 3). The calculated SI of 0.0019 clearly shows that the mixture is a highly synergistic combination of active compounds. It was not possible to calculate the 7-day, 14-day and 28-day SI values, since after this incubation phase the germ counts either could not be determined precisely, as in the case of the individual substances (< 100), or were 0 (compare Table 1). In these special cases, KuII ¹ S equation cannot be used; however, the synergism is also evident for product C in the 7-day values on the basis of the germ count of 0.

Literature : Synergy index:

D.C.Steinberg; Cosmetics & Toiletries 115 (11); p. 59-62 (2000)

F.C.Kull et al.; Applied Microbiology 9; p. 538-541 (1961)

Table 3: Calculation of the synergy index (Sl) at the time 2 days with the aid of the CFU values for product A (phenoxyethanol; dosage: 1 %), product B (tropolone; dosage: 0.01 %) and for the synergistic mixture according to the invention (ratio of amounts of product A and product B: 1 :1; w/w; dosage of

phenoxyethanol: 0.5 %; dosage of tropolone: 0.005%); test germ: Aspergillus niger)

Outstanding results which confirm the superiority of product C according to the invention were likewise obtained in respect of the further test germs.

Formulation examples F1 - F13: Cosmetic formulations comprising mixtures of 2- phenoxyethanol and tropolone

Some efficiently preserved cosmetic formulations comprising mixtures of 2- phenoxyethanol and tropolone according to the invention are given in the following formulations of Formula 1 to Formula 13.

Formulation F1: Anti-wrinkle cream

Formulation F2: Anti-inflammatory lotion

Formulation F3: Sunscreen lotion

Formulation F4: Anti-itch ointment

Formulation F5: Healing Spray

Formulation F6: Soothing Powder

Formulation F7: Moisturising Gel

Formulation F8: Silicone Emulsion

Formulation F9: Hair Conditioner

Formulation F10: Shampoo

Formulation F11: Anti-perspirant Stick

Formulation F12: Lotion Base for Wet Wipes (Emulsion)

Raw Material % weight

Phase 1

Cetearyl Isononanoate, Ceteareth-20, Stearyl Alcohol, Glyceryl 3,00

Stearate, Glycerin, Ceteareth-12, Cetyl Palmitate

Mineral Oil 3,00

Phase 2

Water 84,99

Glycerin 0,50

Propyleneglycol 1 ,00

Hydrolite-5 3,00

Allantoin 0,10

Phase 3

Phenoxyethanol 1 ,00

Tropolone 0.01

Phase 4

Fragrance 0.40

Formulation F 13: Base for Wet Wipes (Solution)