Personal cleansing composition

Abstract

The present invention relates to the delivery of biologically active materials to the skin through personal cleansing compositions. More specifically, the present invention relates to the surprising discovery that active materials such as stearoketonic acid are deposited in much higher amounts than other similar types of fatty acids. Unlike those fatty acids, the present invention ensures that there is no compromise to sensory benefits such as acceptable viscosity. This is achieved by incorporating stearoketonic acid in cleansing compositions comprising synthetic anionic surfactants.

Description

[0001] Invention Field This invention relates to the delivery of bioactive substances to the skin via personal cleansing compositions. More specifically, this invention relates to the surprising discovery of active substances such as stearic acid depositing in much higher quantities compared to other similar types of fatty acids. Unlike those fatty acids, this invention ensures no compromise in sensory benefits such as stability and acceptable viscosity. Background of the Invention Personal care compositions are primarily used to clean localized surfaces of the human and animal body, thereby maintaining hygiene. These compositions are delivered in many forms, such as strips, liquids, gels, and lotions. Personal care compositions, also known as wash-off compositions, are used to remove dirt and grime from the skin. This involves applying a composition, typically diluted with water, to the skin to create a foaming liquid. The foaming liquid, along with dirt and oil, is removed from the skin surface by rinsing with plenty of water.

[0003] To deliver health benefits to the skin, bioactive substances such as vitamins, skin brighteners, sunscreens, and immune-boosting agents are delivered via leave-on compositions such as creams, lotions, gels, and ointments. Delivering them to the skin in sufficient quantities with a cleansing composition to enable their delivery of bioactive effects has always been a challenge. This is because the primary purpose of leave-on compositions is to remove dirt and oil from the surface. Therefore, the competing mechanism for the desired deposition of active substances on the skin surface is a challenge posed by leave-on compositions. An example is fatty acids such as hydroxystearic acid (HSA), which can be deposited on the skin due to its many beneficial bioactive properties. The inventors have found it difficult to deposit sufficient amounts of HSA onto the skin using leave-on compositions. Furthermore, it has been found that HSA undesirably thickens the composition, thus affecting pourability; for example, it has been found difficult to incorporate bioactively effective amounts of 12-HSA (above about 0.5%) into liquid compositions without affecting pourability.

[0004] US2283683 relates to methods for the separation and purification of long-chain aliphatic aminoacyl compounds.

[0005] US5464554 relates to a solid detergent composition.

[0006] DE10 2015 213478A1 relates to a stable mixture, namely a fine dispersion of hydrogenated castor oil in water with anionic, amphoteric and nonionic surfactants, suitable for stabilizing surfactant reagents, particularly for the pearlescent luster of cosmetics.

[0007] The inventors were extremely surprised to discover that stearic acid (KSA), a chemically similar compound that typically exists as an impurity (at most 3% by weight of HSA) during the manufacturing process of HSA, does not function in this manner at all. KSA was found to have excellent deposition properties. Furthermore, they discovered that KSA can be incorporated in much higher amounts than HSA without affecting the viscosity of the liquid composition; that is, it does not thicken as much, thus ensuring good pourability. Other sensory properties, such as foaming, were also observed to be acceptable.

[0008] Therefore, one object of the present invention is to ensure high deposition of bioactive substances from wash-off compositions. Invention Overview This invention relates to a personal hygiene composition comprising: (i) 0.001 to 10.0% by weight of stearic acid; (ii) 3.0 to 80% by weight of synthetic anionic surfactants; and (iii) 5 to 95% by weight of water; The condition is that the composition is substantially free of hydroxystearic acid when stearic acid is in the range of 0.001 to 0.3% by weight.

[0010] Another aspect of the invention relates to a method for ensuring enhanced deposition of stearic acid from a cleansing composition, the method comprising the steps of washing the skin with the composition of the invention, preferably diluted with water, followed by rinsing the skin with water. Invention Details Any feature of one aspect of the invention may be used in any other aspect of the invention. The word “comprising” is intended to mean “including”, but not necessarily “consisting of” or “made up of”. In other words, the listed steps or options need not be exhaustive. Except in the operational and comparative examples, or where otherwise expressly indicated, all figures in this specification indicating the amount of material or reaction conditions, the physical properties of the material, and / or its use should be understood to be modified by the word “about”. Numerical ranges expressed in the format “from x to y” are understood to include both x and y. When multiple preferred ranges are described in the format “from x to y” for a particular feature, it should be understood that all ranges combining different endpoints are also considered. Unless otherwise stated, quantities used herein are expressed as a weight percentage based on the total weight of the composition and may be abbreviated as “weight%”. The use of any and all instances or exemplary language (e.g., “such as”) provided herein is merely for the purpose of better illustrating the invention and is not intended to limit the scope of the otherwise claimed invention in any way.

[0012] The compositions of the present invention are suitable for the purpose of cleaning surfaces (e.g., skin). Preferably, the composition is in liquid form. Liquid form means a composition that is easily poured from a bottle and has a sufficiently high viscosity so that a sufficient amount, for example, 5 to 10 ml, can be poured into a cup-shaped palm. Therefore, the viscosity is preferably in the range of about 10 to about 20,000 mPa·s. A preferred viscosity is in the range of 1,000 to 16,000 mPa·s, more preferably in the range of 1,000 to 10,000 mPa·s. The viscosity is measured at 25°C. The viscosity is measured using a cone / plate Anton Paar viscometer. The cone used is a CP5 with a diameter of 50 mm and an angle of 0.5 degrees. The liquid composition can then be applied to the skin using a suitable method, typically by hand, or using a sponge, loofah, or similar material with plenty of water to create foam; it is then rinsed off with water to clean the surface, such as skin. As used in this article, “skin” refers to the skin on the face and body, including areas such as the neck, chest, back, arms, armpits, hands, legs, and scalp.

[0013] The compositions of the present invention comprise stearic acid. Preferred stearic acids used in the compositions of the present invention are 7-ketostearic acid, 9-ketostearic acid, 10-ketostearic acid, 12-ketostearic acid, and mixtures thereof. The most preferred stearic acid is 12-ketostearic acid. The structure of 12-ketostearic acid is shown below: Stearic acid is preferably contained in the composition at a weight of 0.001 to 10% by weight. Particularly preferred is that stearic acid is contained in the composition at a weight of at least 0.01%, more preferably at least 0.1%, more preferably at least 0.2%, further preferably at least 0.3%, even more preferably at least 0.5%, and most preferably at least 0.8%. Furthermore, particularly preferred is that stearic acid is contained in the composition at a weight of at most 8%, more preferably at most 6%, even more preferably at most 5%, and most preferably at most 4%. A particularly preferred aspect relates to compositions containing 0.2 to 4% by weight of stearic acid.

[0014] When the composition contains 0.001 to 0.3%, more preferably 0.001 to 0.5%, and even more preferably 0.001 to 0.8% stearic acid, it is preferred that the composition is substantially free of hydroxystearic acid. Preferably, the personal care composition is substantially free of hydroxystearic acid.

[0015] "Essentially free of hydroxystearic acid" means that the amount of hydroxystearic acid is less than 0.1% by weight, preferably less than 0.01% by weight, and ideally is not present in the composition. Particularly preferred is that, if present, the amount of hydroxystearic acid is less than the amount of stearic acid present. Hydroxystearic acid can be 10-hydroxystearic acid, 12-hydroxystearic acid, or trihydroxystearic acid (e.g., 9,10,13-trihydroxystearic acid), or trihydroxystearin, or a compound that, upon decomposition, produces one or more hydroxystearic acid or hydroxystearate molecules, such as a monoester, diester, or trimer of glycerol with hydroxystearic acid.

[0016] Throughout this specification, any reference to hydroxystearic acid and stearic acid also includes their salts or esters. Acids can be partially neutralized, therefore compositions may include mixtures of acids and their salts (if applicable).

[0017] The compositions of the present invention further include 3.0 to 80% by weight, preferably 4.0 to 40% by weight, more preferably 4.0 to 20% by weight, of a synthetic anionic surfactant. Preferred synthetic anionic surfactants used in the compositions of the present invention are hydroxyethyl sulfonates, taurine salts, glycine salts, alkyl sulfates, alkyl ether sulfates, succinates, sulfosuccinates, amphoteric acetates, sarcosinates, glutamates, α-olefin sulfonates, lactates, methyl ester sulfonates, and mixtures thereof. Preferably, the anionic surfactant according to the present invention is a synthetic anionic surfactant. The synthetic anionic surfactant according to the present invention is an anionic surfactant other than soap.

[0018] Preferably, the synthetic anionic surfactant is selected from hydroxyethyl sulfonates, taurine salts, glycine salts, alkyl sulfates, alkyl ether sulfates (AES), α-olefin sulfonates (AOS), and mixtures thereof. Even more preferably, alkyl ether sulfates are used as the anionic surfactant in the composition. Anionic surfactants are known to provide foaming and cleaning effects.

[0019] Examples of alkyl sulfates that can be used as anionic surfactants in compositions include sodium dodecyl sulfate (SLS), sodium tetradecyl sulfate, and mixtures thereof. Examples of AES that can be used as synthetic anionic surfactants include anionic surfactants having the following general formula: R1-(OR') n -O-SO3 - M + ,in: R1 is a saturated or unsaturated C8-C. 16 C is preferred 12 -C 14 Alkyl chain; preferably, R1 is a saturated C8-C chain. 16 More preferably saturated C 12 -C14 Alkyl chain; R' is ethylene; n is 1 to 18; preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 5. M + It is a suitable cation that provides electrical neutrality, preferably ammonium, sodium, calcium, potassium or magnesium, and more preferably sodium cation.

[0020] Examples of AES that can be used in compositions to synthesize anionic surfactants include sodium lauryl ether sulfate (SLES), sodium myristyl ether sulfate, and sodium palmityl ether sulfate, and mixtures thereof. Preferred AES are SLES having 1 to 3 ethylene oxide units per molecule. More preferably, SLES have 1 to 2 ethylene oxide units per molecule.

[0021] Another class of particularly desirable synthetic anionic surfactants are alkyl hydroxyethyl sulfonates (e.g., fatty acid esters of hydroxyethyl sulfonates, such as sodium lauroyl hydroxyethyl sulfonate or sodium cocoyl hydroxyethyl sulfonate) and alkyl taurates (e.g., alkyl tauramides, such as N-methyl taurine). It is particularly suitable to include them in surfactant mixtures because they have the advantage of being sulfate-free. Furthermore, they provide the ability to formulate systems at neutral and slightly acidic pH levels.

[0022] Particularly preferred aspects relate to compositions comprising 5 to 20% by weight, preferably 6 to 15% by weight, of a surfactant system comprising (a) an alkali metal acyl hydroxyethyl sulfonate and (b) an alkali metal alkyl taurate.

[0023] Acyl hydroxyethyl sulfonate surfactants are typically produced by fatty acids (e.g., C... 10 To C 16 Fatty acids, such as lauric acid) and hydroxyethyl sulfonates (e.g., HOCH2CH2SO4M) + M + It can be produced by direct esterification in a process commonly referred to as "DEFI" (decoupling of fatty acid hydroxyethyl sulfonates), for example, using sodium or potassium counterions. Preferred hydroxyethyl sulfonates include cocoyl hydroxyethyl sulfonate and lauroyl hydroxyethyl sulfonate, preferably containing sodium or potassium as counterions.

[0024] Other preferred synthetic anionic surfactants used in the compositions of the present invention are alkyl taurates, such as alkyl taurate amides. Such alkyl taurate amides can be derived from taurine; methyl taurine; or the corresponding taurate (e.g., NH₂CH₂CH₂SO₃M). + M +It can be prepared by reacting sodium or potassium counterions with suitable fatty acids. Preferred alkyl tauramides include sodium methylcocoyl taurate and sodium methyllauroyl taurate.

[0025] The composition can also be delivered with a soap other than HSA or KSA salts, using a combination of one or more of the above-described synthetic anionic surfactants. The soap used to prepare the cleaning compositions of the present invention is preferably C8-C. 24 Soap, preferably C 10 -C 20 Soap, C is the best choice 12 -C 18 Soap. The cation of the soap can be an alkali metal, an alkaline earth metal, or ammonium. Preferably, the cation of the soap is selected from sodium, potassium, or ammonium. More preferably, the cation of the soap is sodium or potassium. Fatty acids derived from other suitable oils / fats such as peanut oil, soybean oil, tallow, palm oil, palm kernel oil, etc., can also be used in other desired proportions. This combination of soap and synthetic surfactant is generally referred to as a soap-based synthetic detergent formulation. In a soap-based synthetic detergent formulation, soap can be contained in 0.1 to 30%, preferably 1 to 25%, more preferably 5 to 20% by weight of the composition.

[0026] Preferably, the composition may further comprise 0.1 to 40% by weight of an amphoteric surfactant, nonionic surfactant, or mixture thereof. These provide foam enhancement and improve the sensory properties of the composition. Preferably, the amphoteric surfactant is selected from betaines, sulfobetaines, and amine oxides. Preferred examples are cocamidopropyl betaine (CAPB), cocamidopropyl alcohol amide (CMEA), cocoamphoacetate, and mixtures thereof. When included, the composition preferably comprises 0.1 to 20% by weight, more preferably 1 to 10% by weight of an amphoteric surfactant.

[0027] Suitable nonionic surfactants include addition products of ethylene oxide and / or propylene oxide with fatty alcohols, fatty acids, and fatty amines. Any particular type of alkoxylated material described below can be used as a nonionic surfactant. Preferably, the HLB of the nonionic surfactant is from about 7 to about 20. Polyglucoside-type nonionic surfactants can also be used. When included, the composition preferably contains 0.1 to 20% by weight, more preferably 1 to 10% by weight of a nonionic surfactant.

[0028] The pH of the composition is preferably in the range of 4.0 to 10.5, more preferably in the range of 4.0 to 7.0.

[0029] The pH measurement reported in this invention is as follows: The composition was diluted 1:1 with deionized water, and the pH was measured directly at room temperature (25°C) using a standard pH meter.

[0030] The composition of the present invention is preferably in liquid form, in which case water is preferably present in 40 to 90% by weight.

[0031] Preferably, the composition further comprises a water-soluble / water-dispersible polymer. These polymers can be cationic, anionic, amphoteric, or nonionic with a molecular weight greater than 100,000 Daltons. They are known to improve the viscosity and stability of liquid cleaning compositions, enhance the sensory experience on and after use, and improve foam creaminess and foam stability. Such polymers can preferably be used in amounts of 0.1 to 10% by weight, more preferably 0.1 to 5% by weight, even more preferably 0.25 to 3% by weight, and even more preferably 0.5 to 2% by weight.

[0032] Examples of water-soluble / water-dispersible polymers include carbohydrate gums such as cellulose gum, microcrystalline cellulose, cellulose gel, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, methyl cellulose, ethyl cellulose, guar gum, gum arabic, gum arabic, gum acacia, agar gum, xanthan gum, and mixtures thereof; modified and unmodified starch granules and pregelatinized cold water-soluble starch and phosphate starch; and emulsion polymers such as Aculyn. ® 28. Aculyn ® 22 or Carbopol ® Aqua SF1; cationic polymers, such as modified polysaccharides, including those marketed under the trade name Jaguar ® C13S, Jaguar ® C14S, Jaguar ® C17 or Jaguar ® C16 is cationic guar gum purchased from Rhone Poulenc; cationic modified cellulose, such as UCARE from Amerchol. ® Polymer JR 30 or JR 40; N-Hance from Hercules ® 3000, N-Hance ® 3196, N-Hance ® GPX 215 or N-Hance ® GPX 196; Synthetic cationic polymers, such as Merquat sold by Nalco. ® 100. Merquat ® 280. Merquat ® 281 and Merquat ® 550; cationic starch, such as StaLok sold by Staley Inc. ®100, 200, 300, and 400; cationic galactomannans, such as Galactasol from Henkel, Inc. ® Series; Quadrosoft ® LM-200; and Polyquaternium-24 from Dow ® And Polyquaternium-67. Also suitable are high molecular weight polyethylene glycols, such as Polyox. ® WSR-205 (PEG 14M), Polyox ® WSR-N-60K (PEG 45) and Polyox ® WSR-301 (PEG 90M). Biodegradable polymers are particularly preferred.

[0033] Preferably, the composition further comprises one or more skin whitening agents. Preferably, the skin whitening agent may be selected from ammonium lactate, arbutin, azelaic acid, kojic acid, butylated hydroxyanisole, butylated hydroxytoluene, citrate, 3-diphenylpropane derivatives, ellagic acid, glucopyranosyl-1-ascorbic acid, gluconic acid, hydroquinone, 4-hydroxyanisole, and linoleic acid. The amount of skin whitening agent that may be included in the compositions of the present invention depends on its efficacy, but generally they are included in the composition at 0.01-5% by weight.

[0034] Preferably, the composition further comprises a preservative to protect the composition from the growth of potentially harmful microorganisms. Particularly preferred preservatives include hydantoin derivatives, propionates, various quaternary ammonium compounds, phenoxyethanol, imidazolidinyl urea, octyl glycol, undecylalanine, octylglycine, sodium dehydroacetate, sodium benzoate, and benzyl alcohol. The amount of preservative used is preferably from 0.01% to 2% by weight, more preferably from 0.1% to 1% by weight.

[0035] The composition may also contain emollients such as stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, stearic acid, isobutyl palmitate, isooctyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, octadecane-2-ol, isocetyl alcohol, eicosanol, behenyl alcohol, cetyl palmitate, silicone oils such as dimethyl polysiloxane, di-n-butyl sebacate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, stearyl alcohol, etc. The composition includes butyl myristate, polyethylene glycol, triethylene glycol, lanolin, cocoa butter, shea butter, corn oil, cottonseed oil, olive oil, palm kernel oil, rapeseed oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame oil, coconut oil, peanut oil, castor oil, acetylated lanolin alcohol, petrolatum, mineral oil, butyl myristate, isostearic acid, palmitic acid, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, and myristyl myristate. The emollient may be included in the composition at 0.1 to 15% by weight, preferably 0.1 to 10% by weight.

[0036] The composition may further include a wide range of other optional components, such as antioxidants, bio-additives, buffers, colorants, astringents, fragrances, humectants, sunscreens, conditioning agents, pH adjusters, skin soothing agents, and skin healing agents.

[0037] The composition can also be delivered in solid form, in which case it is preferably in the form of bars. In such cases, soap bars are preferred. Soap bars generally have the following composition: Soap, i.e., fatty acid salts, preferably present in an amount of 5 to 80% by weight, more preferably 10 to 75% by weight, and even more preferably 25 to 75% by weight of the cleaning composition. It may contain a small amount (0.1-10% by weight) of synthetic anionic surfactants, which may be one or more of the synthetic anionic surfactants listed above. Soap bars may include other known ingredients such as fragrances, pigments, preservatives, emollients, gelling agents, and thickeners. The selection of these ingredients depends largely on the form of the composition. Water is a preferred carrier. When water is present, it is preferably present in an amount of at least 1% by weight of the composition, more preferably at least 2%, and even more preferably at least 5%. When water is the carrier, the soap bar may contain 10 to 50% by weight, more preferably 12 to 40% by weight, and even more preferably 12 to 35% by weight of water.

[0038] The cleaning compositions of the present invention can also be delivered via moisturizing strip compositions. Moisturizing strip soap compositions containing fatty acyl hydroxyethyl sulfonates (e.g., cocoyl hydroxyethyl sulfonate) are particularly preferred. Fatty acyl hydroxyethyl sulfonate (e.g., cocoyl hydroxyethyl sulfonate) surfactant "products" are defined as mixtures of anionic acyl hydroxyethyl sulfonate surfactants and fatty acid / fatty acid soaps. They are highly desirable in personal skin or hair cleansing products because they foam well, are gentle on the skin, and have good emollient properties. Typically, fatty acid hydroxyethyl sulfonate surfactant products are produced by esterification of fatty acids or by reaction of fatty acid chlorides with carbon chain lengths of C8-C20 with hydroxyethyl sulfonates. In addition to hydroxyethyl sulfonates, typical fatty acyl hydroxyethyl sulfonate-containing surfactant products contain about 40 to 95% by weight of acidic hydroxyethyl sulfonate and 5 to 50% by weight, typically 10 to 40% by weight, usually less than 5% by weight, of free fatty acids, and trace amounts (less than 2% by weight) of other additives. The content of fatty acid soaps can range from 5 to 15% by weight. It may contain 1 to 5% by weight of other surfactants, such as betaine. Water is typically contained in the composition at 2 to 8% by weight.

[0039] The compositions of the present invention can also be delivered via self-foaming compositions. Preferred self-foaming compositions contain 2.5 to 10% by weight of a surfactant, typically a mixture of synthetic anionic and amphoteric surfactants. Preferred synthetic anionic surfactants are amino acid-based, namely sodium lauroyl glycinate, sodium cocoyl glycinate, sodium lauroyl glutamate, sodium cocoyl glutamate, and may also be selected from one or more of sodium lauroyl hydroxyethyl sulfonate, sodium cocoyl hydroxyethyl sulfonate, α-olefin sulfonate (AOS), or combinations thereof. Amphoteric surfactants may be one or more listed above herein. Self-foaming compositions also typically contain a humectant selected from glycerin, propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexanediol, 1,3-butanediol, isopentyl glycol, 1,2,6-hexanetriol, ethoxylated glycerin, propoxylated glycerin, or combinations thereof. It may also contain a moisturizing agent selected from one or more compounds listed above herein. Self-foaming compositions of this type are typically sulfate-free.

[0040] According to another aspect of the invention, a method is provided to ensure enhanced deposition of stearic acid from a cleansing composition, comprising washing the skin with the composition of the invention (preferably diluted with water), followed by rinsing the skin. The composition can be diluted with water at a weight ratio ranging from 1:5 to 1:500, preferably from 1:10 to 1:100. After the washing step, the skin can be rinsed with plenty of water to substantially remove all of the composition from the skin surface.

[0041] Another aspect of the invention relates to a composition of the invention for depositing stearic acid on the skin when the composition (preferably diluted with water) is used and then the skin is rinsed with water.

[0042] The invention will now be illustrated with the aid of the following non-limiting embodiments.

[0043] Example Examples 1-4: Compared with 12-HSA, 12-KSA deposition on vitro skin Prepare liquid skin cleansing compositions as shown in Table 1.

[0044] Table 1

[0045] Table 2:

[0046] The deposition of active substances (12HSA / 12KSA) on vitro skin was measured using the procedure given below: Remove the vitro skin and cut it into 5×5 cm pieces. Pre-wet with 500 μL of water and rub for 30 seconds. Drain excess water. Apply 0.08 mL of the net product and allow it to foam for 20 seconds. Leave the foam on the vitro skin for 30 seconds. Rinse the vitro skin with 100–120 mL of water for 30 seconds. Extract the vitro skin by sonication with 10 mL of methanol for 25 minutes. Analyze the concentration of active ingredients in the extract using LC-MS. The data are summarized in Table 3 below.

[0047] Table 3

[0048] The composition was too sticky to process, making it impossible to measure the deposition.

[0049] The data in Table 3 above show that 12KSA is much better than 12HSA in the deposition of compositions used for washing substrates.

[0050] Examples 5-7: Rheological properties of various compositions Examples 5-6 were obtained as described above. Furthermore, Example 7 was prepared using a higher amount of 12KSA. These samples were then removed and subjected to two shear rates (0 s⁻¹). -1 and 1 s -1 Rheological properties were measured at these shear rates. The procedure for measuring viscosity at these shear rates is as follows: The viscosity of the samples was measured using a cone / plate Anton Paar viscometer. The cone used was a CP5 with a diameter of 50 mm and an angle of 0.5°. Viscosity was measured using a shear gradient, where the sample was subjected to increasing shear rates, and the viscosity of the sample as a function of the shear rate was observed. All experiments were conducted at 25°C. The data is summarized in Table 4.

[0051] Table 4:

[0052] The data in Table 4 above show that when the increased amount of 12KSA is included, the composition according to the invention does not unnecessarily thicken and remains within an acceptable viscosity range.

Claims

1. A personal hygiene composition comprising: (i) 0.001 to 10.0% by weight of stearic acid; (ii) 3.0 to 80% by weight of synthetic anionic surfactants; and (iii) 5 to 95% by weight of water; The condition is that when the stearic acid is in the range of 0.001 to 0.3% by weight, the composition is substantially free of hydroxystearic acid.

2. The composition of any one of the preceding claims, wherein the composition comprises 0.2 to 4% by weight stearic acid.

3. The composition of any one of the preceding claims, wherein the stearic acid is selected from 7-ketostearic acid, 9-ketostearic acid, 10-ketostearic acid, 12-ketostearic acid and mixtures thereof.

4. The composition according to any one of the preceding claims, wherein the synthetic anionic surfactant is selected from hydroxyethyl sulfonates, taurine salts, glycine salts, alkyl sulfates, alkyl ether sulfates, succinates, sulfosuccinates, amphoteric acetates, sarcosinates, glutamates, α-olefin sulfonates, lactates, methyl ester sulfonates, and mixtures thereof.

5. The composition of any one of the preceding claims further comprises 0.1 to 40% by weight of an amphoteric surfactant, a nonionic surfactant, or a combination thereof.

6. The composition as claimed in any of the preceding claims, wherein the pH of the composition is in the range of 4.0 to 10.

5.

7. The composition as claimed in any of the preceding claims, wherein it is in liquid form.

8. The composition of claim 7, wherein it comprises 40 to 90% by weight water.

9. The composition as described in any one of claims 1 to 6, wherein it is in solid form, preferably in strip form.

10. The composition of claim 9, wherein it comprises 10 to 50% by weight water.

11. The composition as claimed in any of the preceding claims, wherein the composition is substantially free of hydroxystearic acid.

12. A method for ensuring enhanced deposition of stearic acid from a cleansing composition, comprising the steps of washing the skin with the composition according to any one of the preceding claims, the composition preferably diluted with water, followed by rinsing the skin with water.

13. The use of the composition according to any one of claims 1 to 10 for depositing stearic acid onto the skin when the skin is washed with the composition and then rinsed with water, wherein the composition is preferably diluted with water.

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