Makeup removal ingredients

Abstract

Invention details;

Description

[0001] A MAKE-UP REMOVAL COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates to a skin cleaning composition, more particularly a composition for washing the face that is especially useful and effective in removal of make-up.

[0004] Background of the Invention

[0005] People like to use cosmetic products especially on their face and other exposed parts of the body for various benefits e.g. providing even skin tone, smoothening age-related fine wrinkles, providing brightness effect, getting sunscreen benefits etc. Further, makeup products like lipstick, foundations, mascara etc. are applied for beautifying the face, to the individual’s personal desires. Such products contain a variety of ingredients which may be particulate e.g. pigments, inorganic particles, powders and sunblock; oily ingredients like organic sunscreens, emollients, solvents; water soluble ingredients like humectants, polymers, and other skin care actives like vitamins, antiaging actives etc. Such leave-on cosmetic and make up products are so formulated that they are meant to have high substantivity on the skin. Such products are claimed to retain their efficacy on the skin and be stable over long periods of use e.g. up to 8 to 12 hours and not smudge, smear or run when the person perspires or is exposed to changing external conditions like sunlight, pollution, and dry ambient conditions like a heated or air-conditioned room. While on the one hand such products have to be highly substantive on the skin, on the other hand it is necessary that the consumer has to have a simple, safe and mild wash off make-up removal products that ensures that such leave-on cosmetic I make -up products are easily removed without the need for too much mechanical abrasion.

[0006] The most commonly used skin cleansing product is one which contains a combination of synthetic surfactant and soap (often called a soap-syndet composition) for emulsifying the oil and particulates to deliver excellent cleansing benefit. However, such compositions are often found wanting when it comes to efficiency in removal of make up on the face. The present inventors have found that the make-up efficacy is better if a composition is formulated with a combination of a synthetic surfactant (to the exclusion of soap) and free fatty acid. However, such a composition, often termed as a gel-creme product, which is high in water and free fatty acid does not have the desired rheological properties i.e the desired sensory / viscosity when in use. The product has to have certain high viscosity such that it can be easily applied on the face and used for face wash without too much run off and wastage of the product. Further, the composition was found wanting in terms of formulation stability. They found that inclusion of a specific polymer viz. cross-linked acrylate copolymer over a narrow window of pH was able to solve this problem so that the composition not only had the desired formulation stability but had the desired high viscosity. Further it was found to be stable over varied temperature conditions.

[0007] It is thus an object of the present invention to provide for a face wash composition that is highly effective in make-up removal.

[0008] It is yet another object of the present invention to provide for a highly efficient make-up removing face wash composition that is stable on storage over long time and over varying temperature conditions.

[0009] It is yet another object of the present invention that is formulated to have high make-up removal efficacy, is stable over long time and varying temperature conditions and is delivered at a desired high viscosity for easy application and use.

[0010] Summary of the Invention

[0011] The present invention relates to a make-up removal composition comprising

[0012] (i) 1 to 25 wt% synthetic surfactant;

[0013] (ii) 0.1 to 10 wt% free fatty acid;

[0014] (iii) 0.1 to 2.5 wt% thickener which is a crosslinked acrylate copolymer;

[0015] (iv) 0.1 to 1 wt% of an alkali;

[0016] (iv) 40 to 70 wt% water; wherein the composition has a pH in the range of 6.2 to 6.8; and wherein the composition has a viscosity in the range of 15,000 to 35,000 mPa-s.

[0017] Detailed Description of the Invention

[0018] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word "about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

[0019] The topical composition of the invention is meant to be used for personal care or for cosmetic use and could also be referred to as a personal care composition or a cosmetic composition. By a “personal care composition” as used herein, is meant to include a composition for topical application i.e external surfaces of the skin and / or hair of humans. Such a composition may be classified as leave-on or wash off, and includes any product applied to a human body for improving appearance, cleansing, odour control or general aesthetics. The composition of the present invention is preferably a cleansing composition of the wash off type which comprises a synthetic surfactant.

[0020] "Skin" as used herein is meant to include skin on the face and parts of the body (e.g. neck, arms, hands, legs and scalp) which are the exposed parts where one generally tends to apply leave-on cosmetic compositions especially make-up compositions.

[0021] The composition of the invention is of the cleansing type that is of the so called wash-off or rinse- off format. By these formats, is meant that the composition is generally diluted with water and applied on the topical surface e.g. the face and then rinsed off with copious amounts of water after a few minutes. Cleansing composition of the present invention is in the liquid form with a viscosity in the range of 15,000 to 35,000 cps (or millipascal-second; mPa-s) preferably in the range of 15,000 to 25,000 cps (or mPa-s), more preferably in the range of 16,000 to 22,000 cps (or mPa-s). The composition is preferably a Newtonian fluid. The viscosity of the product is measured using a Brookfield Viscometer with RV 6 spindle @ 20 rpm (for 30 to 60 sec, preferably, 30 sec) at 25 ± 2°C.

[0022] The composition of the invention comprises a surfactant which is selected from one or more of an anionic, an amphoteric and a non-ionic surfactant. Preferably the surfactant is selected from one or both of an anionic and an amphoteric surfactant, most preferably a combination of both. The anionic surfactants is preferably selected from an alkyl ether sulphate, primary alkyl sulphate, secondary alkyl sulphonates, alkyl benzene sulphonates, or ethoxylated alkyl sulphates. Especially preferred are sodium lauryl ether sulphate (SLES). The SLES for use in the present invention generally preferably has 1 to 3 Ethoxylate (EO) groups. SLES is preferably included in 3 to 14%, preferably 6 to 12% by dry weight basis of the composition. SLES is generally available as a 30% solution in water. The other surfactant which may be included in the present invention is cocoamide monoethanol amine (CMEA). CMEA is preferably included in 1 to 3% by weight of the composition. One preferred aspect of the liquid cleansing composition of the invention relates to an aspect wherein the surfactant comprises a mixture of sodium lauryl ether sulphate (SLES) and coco amide monoethanol amine (CMEA). Alkyl polyglucoside may also be present in the composition, preferably those having a carbon chain length between Ce and C .

[0023] Another useful surfactant for inclusion in the liquid cleansing composition of the invention is an amphoteric surfactant preferably a betaine surfactant, more preferably an alkyl amidopropyl betaine surfactant for example cocamidopropyl betaine. In a preferred embodiment, the composition comprises from 0.1 to 5 wt.%, preferably from 0.5 to 4 wt.%, more preferably from 1 to 3 wt.% of the amphoteric surfactant.

[0024] Surfactants of the non-ionic class for inclusion in the liquid cleansing composition of the invention are preferably of the polyoxyethylene sorbitan alkyl esters class (sold as Tween surfactants)), fatty alcohol ethoxylates (sold as Brij surfactants), alkyl phenol ethoxylates (sold as Triton surfactants), fatty acid ethoxylates (sold as Myrj surfactants), and Alkyl poly glucosides (sold as Plantacare surfactants). The total amount of surfactant included in the composition of the invention is preferably from 5 to 15%, more preferably 7 to 15% by weight of the composition.

[0025] The composition of the invention comprises 0.1 to 10 wt% free fatty acid. By free fatty acid is meant the amount of fatty acid present in the composition exclusive of any fatty acid that may have converted to soap due to inclusion of the alkali. The free fatty acid is preferably present in 0.1 to 6%, more preferably 4 to 6% by weight of the composition. The free fatty acid preferably comprises C10 to C16 fatty acid, more preferably C12 to C14 fatty acids. For the amount of alkali included in the composition of the invention the amount of soap generated insitu as a consequence of this is at most 1 % by weight of the composition, preferably in the range of 0.1 to 0.5 wt%.

[0026] The composition of the invention comprises a thickener which is a crosslinked acrylate copolymer. It is liquid, acrylic rheology modifier designed to suspend, stabilize, and thicken surfactant-based personal cleansing products and soap-based cleansing systems. A particularly preferred copolymer for use in the composition of the invention is Carbopol Aqua SF-1 acrylic emulsion polymer from Lubrizol. It is especially useful in formulations containing high levels of surfactants. It is an alkali swellable acrylic emulsion polymer. The thickener is included in 0.1 to 2.5%, preferably 0.2 to 2.4% by weight of the composition. The composition of the invention is prepared by including an alkali therein. The alkali is included to ensure that the pH of the composition is carefully adjusted to be in the range of 6.2 to 6.8. pH of the composition is measured using a calibrated pH meter at 25 °C.

[0027] It has been observed that outside this pH range, the composition of the invention does not have the desired viscosity. Below a pH of 6.2, the viscosity drops to some degree which is not acceptable. The composition being a skin cleansing composition is most likely used to remove make up on the face. When doing so, the foams generated by dilution could come in contact with the mucous membranes of the eyes, nose etc. and cause irritation. Thus, a pH as close to 7, preferably higher than 6.2 is preferred for such applications. At a pH higher than 6.8 the viscosity of the composition of the present invention is observed to drop very dramatically. Thus, it is important that the pH be adjusted to be in the range of 6.2 to 6.8 by careful inclusion of desired amount of alkali.

[0028] The alkali to be included to achieve this may be one or more of sodium hydroxide, potassium hydroxide or triethanolamine, preferably potassium hydroxide. Depending on the alkali or combination of alkali used, it may be included in amount of 0.1 to 10 wt%, preferably 0.1 to 2 wt%. When potassium hydroxide is used it is preferably used at 0.1 to 1wt%, more preferably from 0.4 to 0.6% on dry weight basis of the composition.

[0029] The composition of the invention may include a humectant which is generally a polyhydric alcohol. Preferably the humectant is at least one of propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1 ,3-butylene glycol, isoprene glycol, 1 ,3 propanediol, pentylene glycol, hexylene glycol, 1 ,2,6-hexanetriol, glycerol, ethoxylated glycerol, and propoxylated glycerol. Preferred humectants are selected from one or more of glycerine, 1 ,3-butylene glycol, propylene glycol, 1 ,3 propanediol, pentylene glycol, hexylene glycol, and sorbitol. Glycerol is the most preferred humectant. It is preferred that the amount of humectant is 0.1 to 20 %, more preferably 5 to 15% by weight of the composition.

[0030] The composition of the invention is in a thick liquid form with the viscosity range as mentioned hereinabove. Water is present in an amount of 40 to 70%, preferably 40 to 65%, more preferably 50 to 65% by weight of the composition. The composition of the invention may include other known ingredients such as electrolytes, perfumes, pigments, preservatives, emollients, and sunscreens.

[0031] The invention will now be illustrated with the help of the following examples.

[0032] Examples

[0033] Example A,1 : Make up removal efficacy of a composition as per the invention vs. a control sample Composition as per the invention (Example -1) is shown in Table -1. Composition of a control sample (Example -A) outside the invention is shown in Table -2.

[0034] Table -1 : Example -1 : The pH of the above composition was 6.4 and the viscosity was 26,000.

[0035] Table -2: Example -A

[0036] The pH of the above composition was 9.2 and the viscosity was 70,000.

[0037] The two compositions Example 1 and Example A were tested for make-up removal efficacy. The method used to measure the efficacy is give below:

[0038] This study was designed to assess the cleansing and makeup removing (MUR) efficacy of the test product. An in-vitro assessment technique was used for assessment. The skin sample used in the study was an artificial skin a substrate that mimics human skin. It is made to have topography, pH, critical surface tension, chemical reactivity and ionic strength that is similar to human skin. To mimic the real-life scenario, vitro skin was used as a substrate and was exposed to automotive exhaust chamber.

[0039] The presence of make-up was visualized as color on the skin surface. The efficacy of rinse off activity was determined by reduction or removal of make-up by evaluating the presence of white tone.

[0040] The imaging assessment is relatable to the visual appearance. The assessment was based on the grey-tone evaluation using pixel composition. A standard NIH published software Image J * was used for the analysis.

[0041] Determination of cleansing / MUR efficacy of test product:

[0042] Step 1 : Preparation of skin sample: The vitro skin sample was cut into proper shape and size.

[0043] Step 2: lmaging-1 : The digital images of skin sample on the white background was captured.

[0044] Step 3: Make - up application: A standard foundation product was evenly applied to the skin samples after which it was allowed to settle for 10 to 15 minutes and other make up products like Kajal and lipstick was applied over it. Step 4: lmaging-2: The digital images of skin sample on the white background was captured.

[0045] Step 5: Rinse off: The vitro skin sample was pre-wet and specific amount of test product was spread across the sample surface and water was added. The surface was rubbed in linear horizontal direction across the sample surface with uniform pressure 5 times back and forth. The surface was then rinsed for 60 seconds using running de-ionized water.

[0046] Step 6: Drying of the skin sample: The vitro skin sample was dried for 15 minutes in controlled temperature and humidity (25 ± 5°C and 50 ±10% RH).

[0047] Step -7: lmaging-3: The digital images of skin sample on the white background was captured.

[0048] The Imaging data (Imaging 1, 2 and 3) were fed into the software and the mean and standard deviation of selected assessment area was calculated using the following equation:n / . . . > _

[0049] % cleansing 100

[0050] In the present case

[0051] % cleansing = (Imaging 3 - Imaging 2) / (Imaging 1 - Imaging 2) * 100.

[0052] It was observed that sample as per Example - 1 was seen to spread more evenly and easily on hand as compared to sample of Example -A.

[0053] The make-up removal efficacy (% cleansing) is summarised in Table - 3 below:

[0054] Table - 3

[0055] The p- value of the data for Example -1 was < 0.001 vs. control.

[0056] Effect of pH on the viscosity of the samples: Composition as per Example - 1 was prepared at various pH values by varying the amount of alkali used. The viscosity of the samples was measured as described earlier. The data is summarised in Table -4 below: Table - 4:

[0057] The data in the table -4 above indicates that the optimum pH for the composition is in the range of 6.2 to 6.8. Below that range the viscosity drops marginally. Further it is not desirable to go to these low pH ranges as it is not very skin friendly. Above the desired pH range, the viscosity is seen to drop dramatically.

[0058] The data in the table -4 shows that pH influenced the viscosity despite the amount of the crosslinked acrylate copolymer was constant (1.95 wt%) in all these compositions in table -4 above. Further, additional composition as per the present invention (example 2); and a composition outside the present invention (example B) were prepared and are shown in tables 5 and 6 below.

[0059] Table -5: Example -2

[0060] The pH of the above composition was approx. 6.8 and the viscosity was approx. 18450 cps (or mPa-s). Table -6: Example -B

[0061] The pH of the above composition was approx. 7.8 and the viscosity was approx. 8390 cps (or mPa-s).

Claims

DEPCT691. A cosmetic removal composition consisting of (i) 1 to 25% by weight of synthetic surfactants; (ii) 0.1 to 10% by weight of free fatty acids; (iii) 0.1 to 2.5% by weight of thickeners which are crosslinked acrylate copolymers; (iv) 0.1 to 1% by weight of alkali; (iv) 40 to 70% by weight of water; where the composition has a pH in the range of 6.2 to 6.8; and where the composition has a viscosity in the range of 15,000 to 35,000 millipascal-seconds.

2. A composition as claimed in claim 1 where one or more synthetic surfactants are selected. More than in anionic, nonionic and amphoteric surfactants.

3. A composition as claimed in claim 2 where the anionic surfactant is sodium lauryl ether sulfate.

4. A composition as claimed in claim 2 or 3 where the amphoteric surfactant is alkylamidepropyl betaine.

5. A composition as claimed in any of the preceding claims containing 5 to 15% by weight of surfactants.

6. A composition as claimed in any of the preceding claims containing 0% free fatty acids.1 to 6% by weight, ideally 4 to 6% by weight.

7. Composition as claimed in any of the preceding claims, incorporating additional humectants of 0.1 to 20% by weight, ideally 5 to 15% by weight.

8. Composition as claimed in any of the preceding claims, in which the alkali is potassium hydroxide, sodium hydroxide, or triethanolamine, ideally potassium hydroxide.

9. Composition as claimed in claim 8, incorporating potassium hydroxide of 0.4 to 0.6% by weight.

10. Composition as claimed in any of the preceding claims, incorporating soap of at most 1% by weight.