Preservation systems using litsea essential oil

Abstract

The essential oil from Litsea species can be used as a preservative in cleansing compositions for the hair, skin or scalp, in laundry detergent compositions or in hard surface cleaning compositions.

Description

[0001] Henkel AG & Co. KGaA

[0002] Dr. Mundt

[0003] Preservation systems using Litsea essential oil

[0004] The present invention is concerned with the use of essential oil from Litsea species as a preservative in cleansing compositions for the hair, skin or scalp, in laundry detergent composiions or in hard surface cleaning compositions, as well as such compositions comprising Litsea essential oil.

[0005] In order to protect cleansing compositions, laundry detergents and hard surface cleaning compositions from the deleterious effects of microbes, they comprise preservatives. However, many of the antimicrobial actives currently used as preservatives may be problematic for sensitive consumers or users suffering from allergies. Additionally, they are not always biodegradable or obtainable from sustainable sources.

[0006] It is therefore desirable to identify ingredients which also show antimicrobial activity and which can cover the rising demand among consumers for mild, environmentally friendly products.

[0007] The fruit of Litsea species, especially Litsea cubeba, are a known source of essential oil. This essential oil has a lemony fragrance due to its high content of citral, limonene and other components. Citral as the main component can be present in an amount of 50%, in some species even 70 to 85%. It has surprisingly been discovered that the essential oil of Litsea species can be used as a natural preservative.

[0008] In a first embodiment the subject-matter of this invention therefore is the use of essential oil from Litsea species as a preservative in cleansing compositions for the hair, skin or scalp.

[0009] In a second embodiment the subject-matter is the use of essential oil from Litsea species as a preservative in laundry detergent compositions.

[0010] In another embodiment the subject-matter is the use of essential oil from Litsea species as a preservative in hard surface cleaning compositions.

[0011] Further embodiments are cleansing compositions for the hair, skin or scalp, laundry detergent compositions or hard surface cleaning compositions, each comprising essential oil from Litsea species.

[0012] These and other aspects, embodiments, features, and advantages of the invention become apparent to the person skilled in the art in the following detailed description and claims. Each feature from one aspect of the invention can be used in any other aspect of the invention. Furthermore, the examples contained herein are intended to describe and illustrate the invention, but do not restrict it. In particular, the invention is not limited to these examples. 2024PF00286

[0013] 2

[0014] “At least one”, as used herein, means one or more, i.e. 1 , 2, 3, 4, 5, 6, 7, 8, 9 or more of the referenced species. Similarly, “one or more”, as used herein, relates to at least one and comprises 1 , 2, 3, 4, 5, 6, 7, 8, 9 or more. In connection with a given species, the term does not relate to the total number of molecules, but rather to the type of species. “At least one biosurfactant”, for example, thus means that one type of biosurfactant or two or more different types of biosurfactants may be present. In connection with amounts, the term relates to the total amount of the referenced species. With biosurfactants, for example, this means that the given amount is the total amount of all biosurfactants in the composition.

[0015] Numeric values specified without decimal places here refer to the full value specified with one decimal place, i.e. for example, 99 % means 99.0 %, unless otherwise defined.

[0016] The terms “about”, “approximately” or “approx.”, in connection with a numerical value, refer to a variance of ±10 %, preferably ±5 %, with respect to the given numerical value.

[0017] The term “essentially free” within the context of this invention is to be interpreted as the respective compound being contained in the composition in an amount of less than 5 wt.-%, 4 wt.-%, 3 wt.-%, 2 wt.-%, 1.5 wt.-%, 1 wt.-%, 0.75 wt.-%, 0.5 wt.-%, 0.25 wt.-%, 0.1 wt.-%, 0.01 wt.-%, or 0.001 wt.- % based on the total weight of the composition, wherein the amounts are respectively more preferred in descending order. For example, 4 wt.-% is more preferred than 5 wt.-% and 3 wt.-% is more preferred than 4 wt.-%. “Free” within the context of this invention means that the respective compound is not added to the composition as a separate ingredient, so that it may only be present in the form of an additive in a raw material or of an impurity; in such cases it is contained in the composition in an amount of less than 5 wt.-%, 4 wt.-%, 3 wt.-%, 2 wt.-%, 1.5 wt.-%, 1 wt.-%, 0.75 wt.-%, 0.5 wt.-%, 0.25 wt.-%, 0.1 wt.-%, 0.01 wt.-%, or 0.001 wt.-% based on the total weight of the composition, wherein the amounts are respectively more preferred in descending order.

[0018] All percentages given herein in relation to the compositions or formulations relate to weight % (wt.- %) relative to the total weight of the respective composition or formula, if not explicitly stated otherwise. Numeric ranges specified in the format "from x to y" include the specified values. If multiple preferred numeric ranges are specified in this format, it is understood that all ranges created by combining the different endpoints are also included.

[0019] “Cleansing compositions for the hair, skin or scalp” according to the present invention comprise all conceivable compositions used for cleaning and / or conditioning hair, i.e. shampoos, conditioners, lotions and the like, as well as all conceivable compositions used to cleanse the skin, i.e. soaps, shower gels, lotions, serums and the like. 2024PF00286

[0020] 3

[0021] “Laundry detergent compositions” according to the present invention comprise all conceivable textile washing and / or care compositions used in the washing machine or in hand washing. This includes, for example, detergent compositions and compositions for cleaning, care and / or conditioning, pre- and / or post-treatment of all types of textiles, such as garments, carpets, and textile furniture surfaces.

[0022] “Hard surface cleaning compositions” according to the present invention comprise all conceivable compositions used in the household for cleaning and care of hard surfaces, including bathroom and kitchen surfaces and appliances, mirrors, windows and other glass surfaces, floors and furniture, as well as automatic and hand dishwashing compositions.

[0023] The cleansing compositions for the hair, skin or scalp, the laundry detergent compositions and the hard surface cleaning compositions according to the present invention may be in any form known for such products. Thus, they may be liquid, gel-like or paste-like compositions or solid compositions in the form of powders, granules, bars, blocks, tablets and the like. They may also be in the form of a unit-dose composition in a pouch, sachet or the like. The term “liquid”, as used herein, refers to compositions that are flowable and pourable at standard conditions (20 °C and 1013 mbar). Non-Newtonian liquids are comprised as well.

[0024] The Litsea essential oil is preferably obtained from at least one Litsea species selected from the group consisting of Litsea cubeba, Litsea confertiflora, Litsea coriacea, Litsea auriculata, Litsea angustifolia, Litsea glutinosa, Litsea laeta, Litsea lanuginosa or Litsea subcoriacea, most preferably from Litsea cubeba. Litsea species are evergreen or deciduous trees or shrubs belonging to the laurel family, Lauraceae, and are native to parts of Asia and North America. Tthe flowers, leaves and fruit of Litsea species, especially Litsea cubeba, can be used as a source of essential oil with a citrus / lemon fragrance due to their high content of citral as well as limonene and other components.

[0025] In a preferred embodiment, the cleansing compositions for the hair, skin or scalp, the laundry detergent compositions and the hard surface cleaning compositions according to the present invention comprise at least one biosurfactant.

[0026] Biosurfactants usually are surfactants obtained in a fermentation process from bacteria or yeasts. Preferred biosurfactants according to this invention are glycolipids, lipopeptides or lipoproteins. In a preferred embodiment the biosurfactant is a glycolipid, preferably selected from the group consisting of rhamnolipids, sophorolipids and mannosylerythritollipids.

[0027] Sophorolipids are glycolipids consisting of a hydrophobic fatty acid “tail” and a hydrophilic carbohydrate “head” which is sophorose, a disaccharide in which two glucose molecules are connected with a P-1,2 glycosidic bond. The fatty acid is typically a Ci 6-22 saturated or unsaturated 2024PF00286

[0028] 4 hydroxy fatty acid; its terminal or internal OH group is 0-glycosidically linked to the sophorose molecule. The carboxylic end of the fatty acid may be free, as in the following examples:

[0029] Alternatively, they may be internally esterified to form monomeric or dimeric lactones, as in the following examples.

[0030] The open (acidic) form and the lactonic form may also be present simultaneously. In general, lactone sophorolipids are more efficient in reducing surface tension whereas acidic sophorolipids 2024PF00286

[0031] 5 display better foaming properties. The hydroxy groups of the sophorose moiety may also be completely or partially esterified with carboxylic acids such as acetic acid.

[0032] Sophorolipids are produced by various yeast species such as Candida albicans, Candida apicola, Candida floricola, Candida kuoi, Candida riodocensis, Candida stellata, Candida tropicalis, Candida parapsilosis, Rhodotorula bajevae, Rhodotorula bogoriensis, Wickerhamiella domercqiae, Wickerhamomyces anomalus and Starmerella bombicola, and can be obtained from these microorganisms through fermentation.

[0033] Rhamnolipids are glycolipids in which a mono- or di-rhamnose unit is glycosidically linked to the hydroxy group of a p-hydroxy fatty acid, which may in turn be esterified with the hydroxy group of another hydroxylated fatty acid. They can be obtained by fermentation of Pseudomonas bacteria, especially Pseudomonas aeruginosa, preferably grown on hydrophobic substrates such as n- alkanes or vegetable oils.

[0034] Some examples of rhamnolipids are: 2024PF00286

[0035] 6

[0036] There are two main classes of rhamnolipids, namely mono-rhamnolipids, which contain one rhamnose unit, and di-rhamnolipids with two rhamnose groups. Besides C10- carboxylic or hydroxycarboxylic acids, typical rhamnolipids may also contain carboxylic or hydroxycarboxylic acids with longer alkyl chains, such as C12. It is preferred for at least 50 wt.-% of the rhamnolipids to be di-rhamnolipids, preferably at least 90 wt.-% and up to 100%.

[0037] Mannosy lerythritollipids (MELs) are also obtained from various yeasts. They consist of a hydrophilic 4-O-P-D-mannopyranosyl-meso-erythritol moiety and a hydrophobic fatty acid moiety.

[0038] Besides biosurfactants, the cleansing composition for the hair, skin or scalp preferably comprises at least one further ingredient selected from the group consisting of additional surfactants, nonionic polymers, anionic polymers, amino acids, oligopeptides, vitamins, provitamins, vitamin precursors, bio quinones, purine (derivatives), taurine (derivatives), L-carnitine (salts), panthenol, pantothenic acid, 2-furanone (derivatives), ectoine, allantoin, plant extracts, ester oils, UV protective filters, structurants, thickeners, electrolytes, pH regulators, dyes, perfume oils, anti-dandruff agents, opacifiers, pearlescent agents, pigments, stabilizing agents, swelling agents, complexing agents, propellants, preservatives, antioxidants or mixtures thereof.

[0039] The laundry detergent or cleaning composition preferably comprises at least one further ingredient selected from the group consisting of additional surfactants, builders, bleaching agents, bleach activators, bleach catalysts, silver-protecting agents, acids, alkalis, perfumes, solvents, dyes, opacifiers, viscosity regulators, enzymes, electrolytes, complexing agents, hueing dyes, optical brighteners, hydrotropes, soil-release polymers, dye transfer inhibitors, anti-greying agents, antiredeposition agents, antistatic agents, anti-crease agents, corrosion inhibitors, pH adjusters, foam inhibitors, rheology modifiers, rheology stabilizers, ironing aids, bittering agents, shrink-proofing agents, anti-swelling and anti-slip agents, impregnating agents, UV absorbers, antioxidants, skincare substances, softening agents or mixtures thereof.

[0040] In all these compositions the additional surfactant may be selected from anionic, non-ionic, zwitterionic, amphoteric and / or cationic surfactants as well as biosurfactants.

[0041] Among the anionic surfactants that can additionally be used are those of the sulfonate and sulfate types. Surfactants of the sulfonate type that can be used are preferably alkyl benzene sulfonates, olefin sulfonates, i.e. mixtures of alkene and hydroxyalkane sulfonates, and disulfonates, as obtained, for example, from C12-18 monoolefins having a terminal or internal double bond by way of sulfonation with gaseous sulfur trioxide and subsequent alkaline or acid hydrolysis of the sulfonation products. Alkane sulfonates obtained from C12-18 alkanes, for example by way of sulfochlorination or sulfoxidation with subsequent hydrolysis or neutralization, are also suitable. 2024PF00286

[0042] 7

[0043] Likewise, the esters of a-sulfofatty acids (ester sulfonates) are suitable, for example the a- sulfonated methyl esters of hydrogenated coconut fatty acids, palm kernel fatty acids or tallow fatty acids.

[0044] The alkali salts and in particular the sodium salts of the sulfuric acid half-esters of C12-C18 fatty alcohols, for example from coconut fatty alcohol, tallow fatty alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol or stearyl alcohol, or of C10-C20 oxo alcohols and the half-esters of secondary alcohols having these chain lengths are preferred as alk(en)yl sulfates. Alk(en)yl sulfates of the mentioned chain length with synthetic straight-chain alkyl groups prepared from petrochemical sources may also be used. However, it is preferred that the alkyl chain is derived from renewable, natural sources.

[0045] Alkyl ether sulfates are ethoxylated sulfuric acid monoesters of straight-chain or branched alcohols, preferably of C10-C18 fatty alcohols, for example from coconut fatty alcohol, tallow fatty alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol or stearyl alcohol, or of C10-C20 oxo alcohols. They are preferably ethoxylated with 1 to 10 mol of ethylene oxide (EO), especially preferably 1 to 4 EO. A particularly preferred alkyl ether sulfate is sodium laureth sulfate.

[0046] Further suitable anionic surfactants include sulfated fatty acid glycerol esters as well as the salts of alkyl sulfosuccinic acid, which are also referred to as sulfosuccinates or as sulfosuccinic acid esters. Isethionates may also be advantageously used, as may amino acid based surfactants such as taurates, sarcosinates or glutamates. Soaps, especially saturated fatty acid soaps are also suitable, such as the salts of lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and behenic acid, and in particular soap mixtures derived from natural fatty acids, such as coconut fatty acids, palm kernel fatty acids or tallow fatty acids.

[0047] The anionic surfactants, including the soaps, can be present in the form of the sodium, potassium, magnesium or ammonium salts thereof, or as soluble salts of organic bases, such as monoethanolamine, choline or triethylamine. The anionic surfactants are preferably present in the form of the sodium, potassium or magnesium salts, and in particular in the form of the sodium salts.

[0048] Non-ionic surfactants suitable for use include alkoxylated, advantageously ethoxylated, in particular primary alcohols having preferably 8 to 18 C atoms and, on average, 1 to 12 mols of ethylene oxide (EO) per mol of alcohol, in which the alcohol group can be linear or preferably methyl-branched in the 2 position or can contain linear and methyl-branched groups in admixture, as are usually present in oxo alcohol groups. However, alcohol ethoxylates having linear groups of alcohols of native origin having 12 to 18 C atoms, for example of coconut, palm, tallow fatty or oleyl alcohol, and an average of 2 to 8 EO per mol of alcohol, are particularly preferred. Examples of preferred ethoxylated alcohols include 012-14 alcohols having 3 EO or 4 EO, 09-11 alcohol having 7 EO, 2024PF00286

[0049] 8

[0050] C13-15 alcohols having 3 EO, 5 EO, 7 EO or 8 EO, C12-18 alcohols having 3 EO, 5 EO or 7 EO, and mixtures thereof, such as mixtures of 012-14 alcohol having 3 EO and 012-18 alcohol having 5 EO. The degrees of ethoxylation indicated represent statistical averages that can correspond to an integer or a fractional number for a specific product. Preferred alcohol ethoxylates have a narrowed homolog distribution (narrow range ethoxylates, NRE). In addition to these non-ionic surfactants, fatty alcohols having more than 12 EO can also be used. Examples of these are tallow fatty alcohols having 14 EO, 25 EO, 30 EO, or 40 EO.

[0051] Amine oxides are another class of non-ionic surfactants which may be used. They are described by the formula

[0052] R1R2R3NO, in which each R1, R2and R3independently is an unsubstituted or substituted (i.e. hydroxysubstituted) C1-C30 hydrocarbon chain. In preferred amine oxides, R1stands for C12-C18 Alkyl and R2und R3independently of one another are C1-C4 alkyl, especially C12-C18 alkyl dimethylamine oxide. Suitable amine oxides include N-cocoalkyl-N,N-dimethylamine oxide and N-tallowalkyl-N,N- dihydroxyethylamine oxide.

[0053] Another class of non-ionic surfactants that can advantageously be used is the alkyl polyglycosides (APG). Alkyl polyglycosides that can be used satisfy the general formula

[0054] RO(G)z, in which R represents a linear or branched, in particular methyl-branched at the 2-position, saturated or unsaturated aliphatic group having 8 to 22, preferably 12 to 18, C atoms, and G is the symbol that represents a glycose unit having 5 or 6 C atoms, preferably glucose. The degree of glycosidation z is between 1.0 and 4.0, preferably between 1.0 and 2.0, and in particular between 1.1 and 1.4. Linear alkyl polyglycosides are preferably used, which is to say alkyl polyglycosides in which the polyglycol group is a glucose group and the alkyl group is an n-alkyl group.

[0055] Further non-ionic surfactants that may be used include alkoxylated, preferably ethoxylated or ethoxylated and propoxylated fatty acid alkyl esters, preferably having 1 to 4 carbon atoms in the alkyl chain, in particular fatty acid methyl esters, as well as fatty acid alkanolamides and polyhydroxy fatty acid amides.

[0056] Suitable amphoteric or zwitterionic surfactants include betaines, which are described by the formula 2024PF00286

[0057] 9

[0058] (Riii)(Riv)(Rv)N+CH2COO- in which

[0059] R"' stands for an alkyl group with 8 to 25, preferably 10 to 21 carbon atoms, which may additionally contain one or more heteroatoms or groups of heteroatoms such as O, S, NH, C(O), C(O)NH or C(O)O, and

[0060] Rivand Rvindependently stand for identical or different C1-3 alkyl groups.

[0061] Among the betaines, Cio-Cis-alkyl dimethylcarboxymethylbetaine and Cn-C -alkyl amidopropyldimethylcarboxymethylbetaine are preferred. An especially preferred betaine is cocamidopropyl betaine.

[0062] Liquid, gel-like and paste-like compositions may also contain one or more thickeners to regulate and modify their viscosity and their rheological properties. These may be selected from all organic or inorganic thickeners, polymeric or monomeric, known to the skilled person, such as natural organic thickeners and their derivatives, synthetic organic thickeners or inorganic thickeners such as clays or silica. Electrolytes may also be used to regulate viscosity. Organic natural thickeners and their derivatives, such as agar, carrageenan, alginates, pectins, guar gum, gellan gum, starch, dextrin, gelatin casein, carboxymethylcellulose and similar cellulose ethers, hydroxyethyl cellulose, hydroxypropyl cellulose and others, are preferred, as are synthetic organic thickeners such as optionally substituted (meth)acrylic acid polymers, vinyl polymers, polycarboxylic acids, polyethers and the like.

[0063] It is particularly preferred that the compositions are free of other preservatives besides the essential oil from Litsea species.

Claims

2024PF0028610Claims:1 . Use of essential oil from Litsea species as a preservative in cleansing compositions for the hair, skin or scalp.

2. Use of essential oil from Litsea species as a preservative in laundry detergent compositions.

3. Use of essential oil from Litsea species as a preservative in hard surface cleaning compositions4. Use according to any one of claims 1 , 2 or 3, characterized in that the compositions comprise at least one biosurfactant.

5. Use according to any one of the preceding claims, characterized in that the compositions are free of other preservatives besides the essential oil from Litsea species.

6. Use according to any one of the preceding claims, characterized in that the Litsea species used to obtain the essential oil are selected from the group consisting of Litsea cubeba, Litsea confertiflora, Litsea coriacea, Litsea auriculata, Litsea angustifolia, Litsea glutinosa, Litsea laeta, Litsea lanuginosa or Litsea subcoriacea.

7. Cleansing composition for the hair, skin or scalp, characterized in that it comprises essential oil from Litsea species.

8. Laundry detergent composition, characterized in that it comprises essential oil from Litsea species.

9. Hard surface cleaning composition, characterized in that it comprises essential oil from Litsea species.

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