Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q19/00—Preparations for care of the skin
  • A61Q19/10—Washing or bathing preparations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/31—Hydrocarbons
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/46—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing sulfur
  • A61K8/463—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing sulfur containing sulfuric acid derivatives, e.g. sodium lauryl sulfate
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
  • A61K8/81—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • A61K8/8105—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • A61K8/8117—Homopolymers or copolymers of aromatic olefines, e.g. polystyrene; Compositions of derivatives of such polymers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/92—Oils, fats or waxes; Derivatives thereof, e.g. hydrogenation products thereof
  • A61K8/922—Oils, fats or waxes; Derivatives thereof, e.g. hydrogenation products thereof of vegetable origin
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q19/00—Preparations for care of the skin

Definitions

• the present invention relates to a rinse-off composition capable of delivering a skincare active to the skin to achieve a beneficial therapeutic effect, to a process to prepare said composition and to uses thereof.
• the skin is a complex organ and is subject to many biological and microbiological mechanisms. When functioning properly, the skin has very effective barrier properties, being water-proof, flexible and permeable to certain substances. However, it is a common occurrence that one or more processes regulating the condition of the skin are impaired, and the skin does not function effectively or is uncomfortable and/or disfiguring to the patient. For example, the skin may have some dysfunction which may lead to dryness or cracking or even more severe conditions, such as eczema or psoriasis. In addition, the functioning of the skin is subject to further factors, including the normal ageing process as well as extrinsic factors such as UV- radiation, pollution, and contact with many substances, such as detergents, chemicals on clothing and medical treatments. All these factors may affect the barrier properties of the skin to varying degrees.
• compositions comprising one or more skincare actives.
• These compositions are generally applied topically and are chosen to have a beneficial effect on the skin to counteract one or more of the above effects.
• the skincare active or combination of actives chosen according to the particular therapeutic and cosmetic effect desired, contributes to the overall appearance and well-being of the skin.
• the choice of the carrier in the composition is also important as the use of a convenient, pleasant to use composition leads to higher compliance.
• active ingredients arranged to be administered topically must be presented in a carrier which facilitates absorption through the layers of the dermis and epidermis to permit the active to be absorbed at the relevant site of action to achieve a desired therapeutic effect.
• Providing a satisfactory formulation to optimise delivery can be a particular problem for many skincare active ingredients, especially insoluble active ingredients. Firstly, it may be necessary to soubilise these active ingredients so that they can pass effectively through the outer skin membrane and reach the site of action. It is also required that the formulation is cosmetically acceptable to the user and is stable on storage, including maintaining the efficacy of the active and also keeping a satisfactory dispersion thereof throughout the skincare composition.
• compositions containing skincare active ingredients Many reported skincare developments concern improvements in formulating compositions containing skincare active ingredients. However, in cases where there is an impairment of the barrier function, there arises the further potential problem that the skin may not permit satisfactory transport of the active therethrough to the site of action. Furthermore, the effect of having dry or damaged skin is that as well as being uncomfortable, due to excess dryness and/or less flexibility than desired, a patient suffers pain and/or discomfort when substances are applied thereto as the skin may be cracked. Care must also be taken that skincare compositions capable of delivering actives do not exacerbate existing skin conditions. In addition, many compositions do not have the desired level of cosmetic acceptability for the user.
• compositions leave a sticky residue and/or may be non- homogenous leaving smears which take a significant time period to disappear and may rub off the skin and/or stain clothing. Poor cosmetic acceptability also leads to problems in ensuring compliance with the desired therapeutic regime in applying the correct amount of the composition at the correct intervals to ensure optimum treatment. Accordingly, in providing a suitable composition, effective treatment should be combined with ease of administration.
• the user may not apply the skincare composition onto the skin for a satisfactory period in order to allow a sufficient dose of active to be administered to the site of action.
• inconvenience and cosmetic unacceptability are factors in reducing compliance with administering a desired active.
• One way of improving the regularity of application to the skin is to combine the application of the therapeutic composition with existing body cleansing routines. This avoids the inconvenience of requiring an extra stage of skin care, particularly if it is necessary to wait for an oily residue to disappear.
• the application of detergent formulations to dry and cracked skin may be uncomfortable to the patient and may even contribute further to the skin disorder, particularly if it is associated with dysfunction of the skin barrier.
• a skincare composition may be provided which is capable of being applied to the skin and which may be rinsed off, leaving a therapeutically effective amount of skincare active or actives present on the skin to have the desired effect.
• This may be achieved by combining said desired a skincare active or actives in a composition with a carrier system comprising a physiologically acceptable oil in an amount of 25% or more by weight of the composition, in combination with a surfactant selected from an anionic or non-ionic surfactant and a non-aqueous film former, miscible with said oil.
• a surfactant selected from an anionic or non-ionic surfactant and a non-aqueous film former, miscible with said oil.
• the present invention provides a rinse-off composition suitable for topical application, said composition comprising a skincare active ingredient capable of regulating the barrier properties of the skin and a carrier therefor, said carrier comprising a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition; b) a surfactant selected from an anionic surfactant, a non-ionic surfactant or a mixture thereof; and c) a miscible non-aqueous film former.
• the term "rinse-off' as used herein means that said composition is applied to a desired area on the skin surface and rinsed therefrom by applying water to the area.
• the rinsing process removes a portion of the composition from the skin but also deposits a film containing a remaining portion of the composition on the skin.
• the composition may be applied to the skin in the presence or absence of water, for example during or before a shower or bath. However, the composition is rinsed away with water.
• the composition is rubbed or wiped from the skin as it is washed away by the water.
• the rinsing step follows substantially after the application of the composition to a given area on the skin.
• the rubbing action to apply said composition and the rubbing action to rinse away the composition may occur substantially simultaneously.
• an emulsion is formed between the rinsing water and the oil in the composition, facilitated by the surfactant.
• a non-greasy film is deposited on the skin, said film containing therapeutic amounts of said skincare active or actives.
• a composition provided in accordance with the present invention is for topical application to a skin surface. Accordingly, the composition will be cosmetically and/or dermatologically acceptable to the user.
• the above described carrier combination has allowed the preparation of a composition for topical application which contains a very high oil content, namely 25% or more by weight of the composition.
• the composition is capable of forming a satisfactory emulsion which can be rinsed off the skin with water which not only leaves an effective amount of the active ingredient on the skin but achieves this without undesirable residues being associated therewith.
• the efficacious nature of the composition is a result of the combination of surfactants and high level of oil, together with the effect of the film former.
• the combination of the emulsion formed and film deposited provides that the composition is still effective to deposit a therapeutic amount of active ingredient present in the composition on the skin. Accordingly, the amount of active ingredient to be incorporated in the composition falls within an acceptable limit.
• a particular advantage achieved with a composition according to the present invention is a substantial improvement in the regulation of the skin barrier function.
• the composition following application of the composition there is a comfortable skin feeling without the tightness normally associated with dry and cracked skin and a substantial improvement in skin feel.
• a non-oily residue is provided after rinsing, leaving a protective film providing a moisturising effect.
• the composition also provides advantageous stability properties and is cosmetically acceptable to the user, is convenient to use and is easily applied.
• the composition may also provide advantageous hydration properties.
• due to the mild and effective formulations a noticeable increase in compliance has been found which leads to better therapeutic treatment.
• the present system may allow the formulation of hydrophilic and/or lipophilic skincare active ingredients in both aqueous and non-aqueous compositions as desired.
• the presentation of lipophilic ingredients to the skin surface generally presents additional formulation issues in order to solubilise said actives, thus it is a particular advantage of the present invention that substantially insoluble or lipophilic ingredients can be used in the subject compositions.
• the composition includes at least one skincare active ingredient capable of regulating the barrier properties of the skin, for example maintaining and/or restoring and/or improving the function of the skin barrier.
• Such properties generally improve the feel and appearance of the skin.
• the user will have a skin condition which requires treatment, although it may be a temporary skin condition, such as an allergic reaction through exposure to an irritant environment or caused by UV radiation.
• the skincare active ingredient used in accordance with the present invention regulates the function of the skin to allow it to provide an effective barrier between the external environment and the internal organs of the body.
• an abnormal skin barrier function results in dry skin conditions in which cracking of the skin occurs leading to general discomfort, such as eczema or psoriasis, or inflammatory conditions.
• Skincare actives conventionally used for regulating the barrier properties of the skin may be used in compositions according to the invention.
• the skincare active ingredient is effective to treat dysfunction in the skin barrier. More preferably, the skincare active ingredient is useful to treat dry skin conditions and/or inflamed skin conditions.
• the skincare active ingredient is useful to treat one or more skin conditions selected from eczema, psoriasis, rosacea-prone skin, inflamed skin and acne.
• Suitable actives include those known to be useful in the treatment of dry skin conditions, including eczema, for example Allantoin, Dexpanthenol, Lanolin Alcohol, Omega 6 Fatty Acids, Hamamelis, Hyaluronic acid, Evening Primrose Oil, Cholesterol and Ceramides; psoriasis, for example Urea and Polidocanol; rosacea-prone skin for example Ruscogenin and Glycyrrhetinc Acid; and sensitive, allergenic-prone skin for example Acetylhexapeptide-1 and Bisabolol.
• eczema for example Allantoin, Dexpanthenol, Lanolin Alcohol, Omega 6 Fatty Acids, Hamamelis, Hyaluronic acid, Evening Primrose Oil, Cholesterol and Ceramides
• psoriasis for example Urea and Polidocanol
• rosacea-prone skin for example Ruscogenin and Glycyrrhetinc
• Said skincare actives may also include anti-inflammatory compounds, for example selected from the following: steroidal agents selected from hydrocortisone, fluocinolone acetonide, halcinonide, halobetasol propionate, clobetasol propionate, betamethasone dipropionate, betamethasone valerate, and triamcinolone acetonide, and non-steroidal anti-inflammatory agents selected from aspirin, ibuprofen, ketoprofen, naproxen, aloe vera gel, aloe vera, licorice extract, pilewort, Canadian willow root, zinc, and allantoin.
• anti-inflammatory compounds for example selected from the following: steroidal agents selected from hydrocortisone, fluocinolone acetonide, halcinonide, halobetasol propionate, clobetasol propionate, betamethasone dipropionate, betamethasone valerate, and triamcinolone acet
• anti-acne agents including those which have an exfoliation effect on the skin, for example, salicylic acid
• a preferred anti-acne agent is salicylic acid.
• Salicylic acid is preferably incorporated into the composition according to the invention as the free acid.
• the pH of the composition may, and generally will, be such that the salicylic acid exists in the composition in dissociated form.
• the composition may well contain cationic counterions, the salicylic acid may then be thought of as being present in salt form.
• the salicylic acid may be incorporated into the composition in salt form, eg as a salt with a Group I metal, such as sodium salicylate.
• any and all references to salicylic acid should be taken to encompass references to the acid and to dissociated forms and salts thereof.
• preferred active ingredients may include hydrophilic moisturizing agents or regenerating agents or anti-inflammatories and the liposoluble active ingredients may include healing, nutritional or anti-inflammatory agents.
• hydrosoluble active ingredients may be selected from sodium lactate (keratolytic and moisturizing), extracts of Hafnia biolysate (anti-inflammatory and growth factors), extracts of Klebsiella pneumoniae and biolysate (anti-elastase and anti-collagenase).
• the composition includes two or more skincare active ingredients. If more than one active is used in the composition, preferably each active has an effect in treating the barrier function of the skin, especially dysfunction of the skin barrier. Further preferably, at least one skincare active ingredient is lipophilic or substantially insoluble in water.
• a composition according to the invention may comprise a combination of hydrophilic and lipophilic active ingredients. However, preferably each of the skincare actives employed in the composition is lipophilic.
• the total amount of active ingredient present in the composition is from 0.01 % to 30% by weight of the composition, preferably from 0.05% to 15% by weight, more preferably from 0.08% to 5% by weight and most preferably from 0.1 % to 1% by weight of the composition.
• Each active will generally be deposited on the skin in conventional amounts according to its intended use as known by a person skilled in the art. It is generally found that up to 30% skincare active is retained on the skin from that present in the composition, more typically up to 20%, particularly up to 10%. Accordingly, the composition should be formulated to contain approximately between 3 and 20 times the amount of active required to be present on the skin, more usually between 5 and 10 times the amount of active required.
• a therapeutically effective amount of skincare active can be retained in the skin from a rinse-off composition.
• Preferred actives are low dosage actives, which may be formulated in the composition in an amount up to 10% by weight of the composition, of which at least 10% of the amount in said composition weight is retained on the skin after rinsing.
• the ceramide may be of natural, synthetic or semi-synthetic origin.
• the ceramide is preferably selected from ceramides of animal origin (particularly from ox brain or milk), of vegetable origin (particularly from wheat), extracted from micro-organisms (particularly yeasts) or genetically modified organisms or ceramides similar to naturally occurring ceramides, such as trihydroxypalmitamidohydroxypropyl myristyl ether commercially available as ceramide H03 or myristyl palmitamido- serinate commercially available as DERMACIDE, both compounds available from the Sederma Company, 78612 Le Perray en Yvelines Cedex, France.
• the ceramide content of the compositions of the invention can vary from 0.00001 % to 5% by weight of the composition, preferably from 0.0005% to 1 % by weight and more preferably from 0.0001 % to 0.1 % by weight.
• the composition contains a source of linoleic acid, for example a vegetable oil.
• the linoleic acid source comprises one or more vegetable oils rich in linoleic acid containing at least 5% by weight linoleic acid, preferably at least 10% by weight and more preferably at least 20% by weight linoleic acid.
• a source of linoleic acid evening primrose oil (Oenothera Biennis) is preferred.
• the linoleic acid content of the composition can also be obtained by mixing two or more of these oils.
• a semi-synthetic oil can also be used, for example triglyceride enriched with linoleic acid.
• the content of oil rich in linoleic acid of the compositions according to the invention can vary from 0.1 % to 20% by weight, preferably from 0.25% to 10% by eight.
• the linoleic acid content of the compositions can vary from 0.01 to 15%, preferably from 0.02% to 5% by weight.
• the composition also contains a source of cholesterol.
• sources are well known to a person skilled in the art.
• the cholesterol is preferably used in an amount of at least 0.001 % by weight of the composition, more preferably at least 0.005% by weight, especially at least 0.01 % by weight and most preferably at least 0.02% by weight.
• the cholesterol is preferably used in an amount up to 1 % by weight of the composition, more preferably up to 0.5% by weight, especially up to 0.2% by weight and most preferably up to 0.1 % by weight.
• preferably cholesterol is present in an amount of from 0.001 % to 1 % by weight, more preferably in an amount of from 0.005% to 0.5% by weight and most preferably in an amount of from 0.01 % to 0.1% by weight.
• the linoleic acid is present in the composition in combination with a ceramide, said linoleic acid being in an amount of 1 to 200 parts by weight per part by weight ceramide, more preferably 10 to 100 parts by weight per part by weight ceramide.
• the cholesterol is present in the composition in combination with a ceramide, said cholesterol being in an amount of 1 to 200 parts by weight per part by weight ceramide, more preferably 10 to 100 parts by weight per part by weight ceramide.
• An especially preferred embodiment of the present invention comprises evening primrose oil (Oenothera Biennis), cholesterol and ceramide H03. Conveniently, this combination may be employed to an extent of linoleic acid in an amount of 1 to 200 parts by weight per part by weight ceramide and cholesterol in an amount from 1 to 200 parts by weight per part by weight ceramide.
• the compositions of the invention can optionally also contain an additional auxiliary hydrosoluble or liposoluble active ingredient, useful in treating conditions other than regulating the barrier properties of the skin.
• Other auxiliary actives may include anti-microbial or antibacterial agents, anti-viral agents, anti-fungal agents and anthelmintic agents. These may be used in combination with the skincare active ingredients effective to regulate the barrier properties of the skin to treat desired symptoms.
• Preferred auxiliary active ingredients may also include one or more of the following:
• antimicrobial or antibacterial compounds for example selected from the following:
• triclosan neomycin, clindamycin, polymyxin, bacitracin, benzoyl peroxide, hydrogen peroxide, tetracylines such as doxycycline or minocycline, sulfa drugs such as sulfacetamide, penicillins, cephalosporins such as cephalexin, and quinolones such as lomefloxacin, olfoxacin or trovafloxacin;
• antiviral compounds for example selected from acyclovir, tamvir, and penciclovir;
• antifungal compounds for example selected from the following: farnesol, clotrimazole, ketoconazole, econazole, fluconazole, calcium or zinc undecylenate, undecylenic acid, butenafine hydrochloride, ciclopirox olaimine, miconazole nitrate, nystatin, sulconazole, and terbinafine hydrochloride; and
• anthelmintic compounds for example metronidazole.
• a composition according to the present invention comprises a carrier comprising a physiologically acceptable oil for topical application.
• the oil is cosmetically and/or dermatologically acceptable.
• the oil is present in a sufficient amount to solubilise any insoluble skincare active ingredient for delivery onto and absorption into the skin, even though the composition is rinsed off the skin with water substantially immediately after application.
• the oil also has emollient properties on the skin and thus may also contribute to an enhancement of the barrier properties of the skin, in addition to that provided by the skincare active ingredient.
• the physiologically effective oil useful in accordance with the present invention may be any cosmetically and/or dermatologically acceptable synthetic or natural oil known to the person skilled in the art.
• oils preferably provide emollient properties on the skin, for example to maintain the soft, smooth and pliable appearance of the skin.
• Emollients function by their ability to act as lubricants and reduce flaking on the surface of the skin.
• the oily phase excipients may be hydrocarbons, silicone oils, triglycerides, waxes, fatty acids, fatty acid alcohols and esters thereof, mineral oils, vegetable oils and hydrogenated vegetable oils, lanolin or mixtures thereof.
• hydrocarbons examples include paraffins (for example paraffinum liquidum and white soft paraffin), petrolatum, hydrogenated polyisobutene, alkyl benzoates, isohexadecane, isododecane, isononyl isonanoate, diisopropylcyclohexane;
• silicone oils include dimethicone, cyclomethicone or cetyldimethicone;
• triglycerides include natural triglycerides and synthetic or semi-synthetic triglycerides;
• waxes include vegetable waxes such as carnauba wax, animal waxes such as beeswax, and mineral waxes such as paraffin wax, ozokerite;
• esters of fatty acids or alcohols include isopropyl palmitate, isopropyl myristate, dioctylmaleate, glyceryl oleate and cetostearyl isononanoate, oct
• the oil selected for any composition may depend on the type of composition desired.
• Preferred oils are silicone oils, mineral oils, vegetable oils and triglycerides.
• a further preferred group of oils are mineral oils, vegetable oils and triglycerides, especially mineral oils and vegetable oils.
• the mineral oil comprises paraffinum liquidum or petrolatum or a mixture thereof.
• a particularly preferred source of paraffinum liquidum is Versagel available from Penreco, 138 Petrolia Karns City USA. This ingredient may be combined with additional paraffinum liquidum or petrolatum as required in order to improve the emollient properties.
• the vegetable oil comprises at least one oil selected from soy bean oil, jojoba oil and coconut oil. Soybean oil is especially preferred.
• oils may be used in an amount of 25% or more of the composition, preferably at least 35% by weight of the composition.
• the oil content may be determined by whether it is desired to formulate the composition according to the invention as an aqueous emulsion or a non-aqueous system.
• the oil is preferably present in the composition in an amount greater than 30% by weight, more preferably greater than 35% by weight, advantageously greater than 40% by weight and most preferably greater than 45% by weight of the composition.
• the oil generally provides the largest component by weight of the composition.
• the oil comprises the major ingredient of the composition. It may, for example, form over half of the composition by weight, preferably greater than 60% by weight, more preferably greater than 70% by weight, and most preferably greater than 80% by weight of the composition.
• the oil may be used up to an extent of 99% by weight of the composition, however, for cosmetic acceptability, additional ingredients may be desired.
• upper limits to the amount of oil present in the composition may conveniently be values such as 90% by weight, 94% by weight, 95% by weight or 98% by weight.
• the oil is suitably present in an amount from 25% to 99% by weight of the composition, preferably from 50% to 98% by weight, more preferably from 60% to 95% by weight and most preferably from 70% to 94% by weight of the composition.
• the oil content may be 25% by weight of the composition or more, preferably 30% or more by weight, more preferably 34% or more by weight and most preferably 38% or more by weight of the composition.
• Upper limits to the amount of oil present when the composition comprises an aqueous emulsion may conveniently be values such as 70% by weight, 60% by weight, 50% by weight or 45% by weight of the composition.
• the oil is advantageously present in an amount from 25% to 70% by weight, preferably from 30% to 60% by weight, more preferably from 34% to 50% by weight and most preferably from 38% to 45% by weight of the composition.
• the ratio of oil to water is in the range 1 :5 to 5:1 parts by weight, preferably 1 :1 to 2:1 parts by weight.
• the water preferably forms between 10% and 50% by weight, more preferably between 20% and 30% by weight, of the composition.
• a composition according to the present invention comprises a surfactant.
• the surfactant used is capable of forming an emulsion substantially immediately with the physiologically acceptable oil in the presence of water, even when the composition comprises a high oil content, ie 25% or more by weight of the composition.
• the surfactant allows the formation of an emulsion which may be rinsed off by water. Following topical application to the skin and rinsing off with water, a portion of the composition is rinsed off the skin and a further portion of the composition is retained on the skin to form a cosmetically acceptable film on the skin. It is a particular advantage of the invention that the formation of the emulsion allows a substantial proportion of the active to be retained on the skin, even though water is applied to rinse the composition away.
• the composition may also have wetting and cleaning properties on the skin.
• the surfactant is selected from one or more non-ionic or anionic surfactants or a mixture thereof, although small amounts of cationic and/or amphoteric surfactants may also be incorporated in compositions according to the present invention, either as separate components or admixed in combination with other surfactants.
• non-ionic surfactants include the class of ethoxylated fatty alcohols and other surfactants such as oleth-5, PEG-5 cocamide, polysorbate 20, PEG-40 hydrogenated castor oil, alkyl poly(ethylene oxide), copolymers of poly(ethylene oxide) and poly(propylene oxide) (commercially called Poloxamers or Poloxamines), alkyl polyglucosides, including: octyl glucoside, decyl maltoside, fatty alcohols, cetyl alcohol, oleyl alcohol;
• anionic surfactants includes the class of alkyl ether sulphates, such as sodium lauryl sulphate, sodium laureth sulphate, sodium dodecyl sulfate, ammonium lauryl sulfate, ammonium laureth sulphate, sodium C12- 15 pareth sulphate and disodium laureth sulfosuccinate, soaps or fatty acid salts ;
• non-ionic surfactants preferably have a HLB in the range 6-20, more preferably 6-12.
• Anionic surfactants preferably have a HLB greater than 20.
• a preferred class of surfactants has only an emulsifying action without a detergent action, ie emulsifiers. This may be useful where it is desired to improve the barrier properties of the skin without requiring the skin to be cleaned first. This forms a preferred feature in non-aqueous systems.
• one class of preferred surfactants are emulsifying surfactants, particularly non-ionic emulsifying surfactants, for example ethoxylated fatty alcohols, preferably ethylene glycol ethers of lauryl alcohol that conform to the formula
• n 1 -10
• Preferred surfactants are laureth-2, laureth-4, laureth-6.5 or a mixture thereof, especially laureth-2 and/or laureth-4. Further preferably emulsifying surfactants are used in a composition substantially free of water.
• emulsifier capable of providing an oil-in-water emulsion in compositions containing a high level of oil
• Such an emulsion may be formed either on admixture with any water present in the composition and/or on rinsing the composition off the skin with water.
• Known cosmetically acceptable emulsifiers include:
• sesquioleates such as sorbitan sesquioleate, available commercially for example under the trade name Arlacel 83 (ICI), or polyglyceryl-2- sesquioleate
• ethoxylated esters of derivatives of natural oils such as the polyethoxylated ester of hydrogenated castor oil available commercially for example under the trade name Arlacel 989 (ICI)
• silicone emulsifiers such as silicone polyols available commercially for example under the trade name ABIL WS08 (Th.
• Goldschmidt AG Goldschmidt AG
• ethoxylated fatty alcohols for example the emulsifiers available commercially under the trade name Brij (ICI);
• e) sorbitan esters for example the emulsifiers available commercially under the trade name Span (ICI);
• ethoxylated sorbitan esters for example the emulsifiers available commercially under the trade name Tween (ICI);
• g) ethoxylated fatty acid esters such as ethoxylated stearates for example the emulsifiers available commercially under the trade name Myrj (ICI);
• h) ethoxylated mono-, di-, and tri-glycerides for example the emulsifiers available commercially under the trade name Labrafil (Alfa Chem.);
• i) non-ionic self-emulsifying waxes for example the wax available commercially under the trade name Polawax (Croda);
• Such emulsifying surfactants are preferably present in an amount up to 15% by weight of the composition, more preferably in an amount up to 10% by weight, especially in an amount up to 5% by weight, for example 4% or 2% by weight of the composition.
• the lower amount of the surfactant will depend on the amount of oil present in the composition and the type of composition required, for example, the properties of the emulsion formed on rinsing or whether a high level of oil needs to be left on the skin, for example minimum values of 0.1 % by weight, 0.5% by weight and 1 % by weight could be considered to provide efficacious results.
• an anionic and/or non-ionic surfactant in an amount of at least 2.5% by weight, especially at least 3.5% by weight of the composition.
• the surfactants, especially non-ionic surfactants may be present in an amount of from 0.1 % to 15% by weight, preferably from 0.5% to 10% by weight, more preferably from 1 % to 5% by weight, most preferably from 2.5% to 5% by weight and especially from 3.5% to 5% by weight of the composition.
• a second embodiment of the invention provides aqueous emulsions.
• Such systems may include the surfactants, including emulsifiers, described above.
• a preferred emulsifier system maintains a stable emulsion on storage but is capable of forming a foam when applied to the skin on rinsing with water.
• an emulsifying surfactant is combined with a surfactant with detergent action.
• a preferred class of surfactants are structured surfactants which cause the compositions to form a foam and have a detergent action. This may be useful where it is desired to clean the skin before applying a skincare active to improve the barrier properties of the skin. This forms a preferred feature of aqueous systems.
• a valuable surfactant combination includes a) an alkyl ether sulphate commercially available Sodium Trideceth Sulphate, present in surfactant systems under the trade names Cedepal TD (from Stepan, Northfield, Illinois, USA), Genapol XRO (from Clariant, Munchenstein, Switzerland) and Miracare SLB 205 (from Rhodia, Aubervilliers, France); and/or b) an alkylamido alkylamine commercially available as a betaine, for instance Sodium Lauroamphoacetate, present in surfactant systems under the trade names Genegen LDA (from Clariant), Miranol HMA and Miracare SLB 205 (both from Rhodia); and/or c) Alkanolamide commercially available as Cocamide DEA, present in surfactant systems under the trade name Comperlan 100 (Cognis, Dusseldorf, Germany).
• the anionic surfactant may aid the production of liquid crystals.
• Liquid crystals may provide advantageous skin care characteristics, for example in terms of skin penetration and hydration than conventional washes. It is believed that this may occur as the liquid crystals are formed into a similar self-organizing structure as natural stratum corneum lipids, and thus show a high affinity to the skin.
• the liquid crystals provide both a structure for the incorporation of the oil which will be released on skin and also provide a rich lather. Sufficient surfactant should be incorporated into the carrier to generate a satisfactory detergent foam.
• a preferred surfactant is a mixture of an anionic surfactant with an amphoteric surfactant, preferably comprising a mixture of sodium trideceth sulphate and sodium lauroamphoacetate, such as is available from Rhodia, 93308 Aubervilliers, France under the trade name Miracare SLB 205.
• Such surfactants may be present in an amount up to 50% by weight of the composition, preferably up to 45% by weight of the composition, more preferably in an amount up to 40% by weight, especially in an amount up to 35% by weight and most preferably up to 30% by weight of the composition.
• the lower amount of the surfactant will depend on the amount of oil present in the composition and the type of composition required, for example whether a lather is required or the amount of film deposited on the skin, for example minimum values of 1% by weight, 10%, by weight and 25% by weight could be considered to be preferred.
• the total surfactant may be present in an amount of from 1 to 45% by weight, preferably from 10% to 45% by weight, more preferably from 15% to 45% by weight and most preferably from 25% to 30% by weight of the composition.
• the composition may also include additional anionic and non-ionic emulsifiers as desired.
• a preferred surfactant combination comprises an ethylene glycol ether of lauryl alcohol, sodium trideceth sulphate and sodium lauroamphoacetate.
• a composition according to the invention also comprises a non-aqueous film former arranged to retain said active on the skin when the composition is rinsed off.
• the film former is capable of forming a membrane on the skin arranged to support the skincare active ingredient in a stable system at the same time as an emulsion of the composition is rinsed from the skin.
• the film former comprises a gel-forming polymer.
• the film-former is present in the composition in an amount from 0.01% to 10% by weight, preferably from 0.05% to 8% by weight, more preferably from 0.1 % to 5% by weight, of the composition.
• the film former is miscible with the carrier comprising the oil and the surfactant.
• the choice of film former may be determined by the presence of water in the carrier but will be within the formulation knowledge of the person skilled in the art to provide a miscible combination of film former with the components of the carrier depending on whether an aqueous or nonaqueous carrier is required.
• the film former is arranged to provide a membrane comprising said active ingredients on the skin when the composition is rinsed away.
• the membrane may be in the form of a film or a gel layer, preferably a gel.
• the non-aqueous film former may be a hydrocarbon polymer film former, for example a styrene copolymer, preferably a hydrogenated alkylene-styrene copolymer, more preferably a hydrogenated butylene/ethylene/styrene copolymer or a hydrogenated ethylene/propylene/styrene copolymer or a mixture thereof.
• a particularly suitable styrene copolymer is incorporated in Versagel M750 (Mineral oil, hydrogenated butylene/ethylene/styrene copolymer; hydrogenated ethylene/propylene/styrene copolymer) available from Penreco. These copolymers are preferred in non-aqueous systems.
• a gel may be formed on interaction between the styrene copolymer and the oil and forms a protective membrane when it is applied to the skin.
• the film former serves to deposit and maintain a layer of the oil containing the skincare active on the surface of the skin.
• a styrene copolymer film-former is preferably present in the composition in an amount from 0.1% to 10% by weight of the composition, more preferably from 1% to 5% by weight of the composition.
• the film former may be combined with a structuring agent, said structuring agent being capable of forming a foam on application to the skin in the presence of water, the film former also being capable of reacting with water and forming a gel.
• a structuring agent capable of forming a foam on application to the skin in the presence of water
• the film former also being capable of reacting with water and forming a gel.
• the formation of the gel on the skin underneath the foam thus acts to deposit a film containing said active on the surface of the skin.
• the film former may be integrated in the lamellar liquid phase.
• a film or gel layer on the skin is formed and the skincare active deposited on the surface of the skin for transport through the skin membrane to the site of action.
• the detergent foam is rinsed from the skin.
• a cationic polysaccharide film former is preferred, especially a cationic guar gum derivative.
• a particularly preferred aqueous emulsion comprises a cationic guar gum derivative comprising hydroxypropyl guar hydroxypropyltrimonium chloride, for example available under the trade name Jaguar C-162 from Rhodia, Aubervilliers, France.
• the cationic polysaccharide is present in an amount from 0.02% to 2% by weight, more preferably 0.05 to 1% by weight of the composition.
• compositions according to the present invention may be in the form of oily dispersions, oil-in-water emulsions, foams or structured liquids which may be emulsions or may be capable of forming foams when shear forces are applied.
• the composition will generally contain a solvent system or other continuous liquid phase. Such a system may be aqueous.
• compositions according to the present invention may be substantially free of water or may contain water in an appropriate amount, for example up to 75% by weight of the composition.
• water When water is present, it is preferably used in an amount of at least 1 % by weight of the composition, more preferably at least 5% by weight, especially at least 10% by weight and most preferably at least 20% by weight.
• the maximum amount of water which may be present in the carrier is up to 75% by weight of the composition.
• the upper limit of water will depend on the amounts of other ingredients incorporated in the composition so that the water may form the remainder of the composition up to 100% by weight.
• water may be used in an amount up to 60% by weight of the composition, more preferably up to 50% by weight, especially up to 40% by weight and most preferably up to 30% by weight.
• the viscosity may be in the range from 1 to 100,000 mPa.s, preferably from 5 to 50,000 mPa.s.
• the viscosity of the composition may be measured using a Brookfield RVT viscometer equipped with a spindle 6 rotating at 10rpm after 2 minutes.
• composition according to the invention may contain optional ingredients, for example to improve the therapeutic effect, to improve the manufacturing process, to improve storage stability and or increase acceptability to the consumer.
• composition may additionally comprise other components which will be well known to those skilled in the art. These include, for example:
• Emulsion stabilising salts such as sodium chloride, sodium citrate or magnesium sulphate.
• Preservatives - ingredients which prevent or retard microbial growth and thus protect the composition from spoilage.
• preservatives include such as propylparaben, bronopol, sodium dehydroacetate, polyhexamethylenebiguanide hydrochloride, isothiazolone and diazolidinylurea.
• Chelating agents or sequestering agents (sequestrants) - ingredients that have the ability to complex with and inactivate metallic ions in order to prevent their adverse effects on the stability or appearance of the composition, as described above.
• chelating agents are ethylenediamine tetraacetic acid and its salts, notably the dipotassium and especially the disodium or tetrasodium salt.
• Abrasives ingredients used to assist in the removal of unwanted tissue or foreign materials from the skin during application of the composition.
• Abrasives commonly comprise fine solid particles.
• a suitable abrasive is polyethylene beads.
• pH adjusters Ingredients used to control the pH of the composition. Examples of pH adjusters are inorganic salts such as sodium hydroxide, and organic bases such as triethanolamine.
• composition according to the invention is applied to the skin for example by rubbing or massaging into the skin and is then rinsed off, for example with water. Although a portion of the composition is washed away, a thin film containing the solubilised actives is retained on the skin and it has been found that this is sufficient to deliver a beneficial therapeutic effect even with very low quantities of active ingredients.
• the composition retained on the skin has been found to easy and comfortable to apply, does not have a drying effect and has a pleasant feel on the skin. It may also hydrate as well as softening the skin and reduces the dryness associated with many skin conditions.
• a method for the prophylactic or remedial treatment of acne comprises the topical application of a rinse-off composition to the skin of a patient, the composition comprising a skincare active ingredient capable of regulating the barrier properties of the skin and a carrier, said carrier comprising a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition; b) a surfactant selected from an anionic surfactant, a non-ionic surfactant or a mixture thereof; and c) a miscible non-aqueous film former.
• the method according to this aspect of the invention may be a therapeutic method, but will often be a primarily cosmetic method, the objective of which is to reduce or eliminate externally visible, and often unsightly, symptoms of acne.
• a rinse-off composition to treat a skin condition associated with dysfunction of the skin barrier, said composition comprising a skincare active ingredient capable of regulating the barrier properties of skin and a carrier therefor, said carrier comprising
• composition (a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition;
• a surfactant selected from an anionic surfactant, a non-ionic surfactant or a mixture thereof;
• a portion of said composition is capable of forming an emulsion in the presence of water and a further portion is capable of forming a film comprising said skincare active ingredient on the affected skin.
• a carrier in the manufacture of a rinse-off composition for the treatment of a dry and/or inflamed skin condition, said composition comprising a skincare active ingredient capable of regulating the barrier properties of skin, said carrier comprising
• composition (a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition;
• a surfactant selected from an anionic surfactant, a non-ionic surfactant or a mixture thereof;
• a method of depositing a therapeutically effective amount of a skincare active ingredient on the surface of dry and/or inflamed skin said skincare active ingredient being capable of regulating skin barrier function, comprising the steps of: i) administering a rinse-off composition comprising said active ingredient admixed with a carrier, said carrier comprising a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition, b) a surfactant comprising an anionic surfactant, a non-ionic surfactant or a mixture thereof; and c) a miscible non-aqueous film former; and ii) applying water to rinse a portion of said composition from the skin and deposit a film comprising a further portion of the composition on the skin.
• a method of treating dysfunction of the skin barrier comprising i) the administration of a rinse-off composition, said composition comprising a skin care active ingredient capable of regulating skin barrier function and a carrier therefor, said carrier comprising a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition, b) a surfactant comprising an anionic surfactant, a non-ionic surfactant or a mixture thereof; and c) a miscible non-aqueous film former; and ii) applying water to form an emulsion capable of being rinsed from the skin leaving a film deposit comprising a therapeutically effective amount of said active ingredient on the skin.
• a method of moisturising the skin comprising i) the administration of a rinse-off composition, said composition comprising a skin care active ingredient capable of regulating skin barrier function and a carrier therefor, said carrier comprising a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition, b) a surfactant comprising an anionic surfactant, a non-ionic surfactant or a mixture thereof; and c) a miscible non-aqueous film former; and ii) applying water to form an emulsion capable of being rinsed from the skin leaving a film deposit comprising a therapeutically effective amount of said active ingredient on the skin.
• a skincare active ingredient effective in regulating the skin barrier function is administered to the skin in a rinse-off composition
• a rinse-off composition comprising the steps of i) combining said active ingredient with a carrier comprising a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition; b) a surfactant selected from an anionic, a non-ionic surfactant or a mixture thereof; and c) a miscible non-aqueous surfactant film former; ii) applying said composition to the skin; and iii) applying water to rinse away a portion of said composition and form a film comprising a therapeutically effective amount of said active on the skin.
• a further aspect of the present invention provides a method of retaining a skincare active ingredient effective in the treatment of skin barrier function on the surface of the skin comprising administering a rinse off composition comprising said active ingredient admixed with a carrier comprising a) a physiologically acceptable oil present in an amount of at least 25% by weight of the composition, b) a surfactant selected from an anionic or a non-ionic surfactant or a mixture thereof; and c) a miscible non-aqueous surfactant film former, followed by applying water to rinse away a portion of said composition and form a film comprising a therapeutically effective amount of said active on the skin.
• the present invention also provides a process to prepare a rinse off composition as previously described comprising combining said active ingredient with said physiologically acceptable oil.
• said active ingredient is combined with a mixture of said oil and said surfactant.
• Further ingredients may be incorporated into the oil/active ingredient mixture before and/or after mixing with said active ingredient.
• One or more active ingredients may be added at different stages of the process.
• a composition may be formed in which the oil provides the continuous phase.
• an aqueous emulsion is formed.
• the one or more surfactants are mixed with the water, followed by the addition of the oil.
• the oil phase includes one or more active ingredients.
• a process according to the invention may also include the step of heating said oil, optionally in combination with one or more additional ingredients, to a temperature in the range 50-100 0 C.
• the one or more active ingredients may be included in the mixture before or after the heating stage.
• trihydroxypalmitamidohydroxypropyl myristyl ether is available from Sederma, Paris, France under the trade name Ceramide H03.
• Examples 1-3 a mixture of paraffinum liquidum (90%), hydrogenated ethylene/propylene/styrene copolymer (5%), hydrogenated butylene/ethylene/styrene copolymer (5%), butyl hydroxyl toluene (0.1 %), tetradibutyl pentaerithrityl hydroxyhydrocinnamate (0.01 %) is available from Penreco, 138 Petrolia Karns City USA under the trade name Versagel;.
• the anionic surfactant is a mixture of sodium trideceth sulphate (-20%), sodium lauramphoacetate (-33.5%) and sodium chloride (-2.5%) is available from Rhodia, under the trade name Miracare SLB 205.
• Example 1 In-shower conditioner
• Example 2 The composition of Example 2 was prepared in a similar manner to that described in Example 1.
• Example 3 In-shower conditioner
• Example 3 The composition of Example 3 was prepared in a similar manner to that described in Example 1.
• Example 4 Structured Liquid
• Anti-oxidant 1 0.05
• Anti-oxidant is a blend of lecithin (-40%), tocopherol (-17%), ascorbyl palmitate (-35%) and hydrogenated palm glycerides available from Cognis under the trade name Controx VP.
• Anti-oxidant 1 (as Example 4) 0.05
• Enteromorpha Compressa Extract (20%) is contained in butylene glycol (40%) and glycerine (40%) available as Enteline 2 from Secma.
• Example 5 The composition of Example 5 was prepared in a similar manner to that described in Example 4.
• Anionic surfactant 30.0 Laureth-2 2.0 Coconut Oil 40 .0 Tocopherol 0 .1 Citric Acid 0 .8 Sodium Chloride 2 .0 Citric Acid 0.5 Preservative 0.9 Water to 100%
• Example 6 The composition of Example 6 was prepared in a similar manner to that described in Example 4. To this carrier may be added one or more skincare active ingredients
• Example 7 The composition of Example 7 was prepared in a similar manner to that described in Example 4. To this carrier may be added one or more skincare active ingredients.
• Anti-oxidant 1 0.05
• Example 8 The composition of Example 8 was prepared in a similar manner to that described in Example 4. Clinical Study
• composition A was applied at least once per day for seven days and a subjective assessment made by each subject.
• Composition A (Structured Liquid)
• the anionic surfactant is a mixture of sodium trideceth sulphate (-20%), sodium lauramphoacetate (-33.5%) and sodium chloride (-2.5%) is available from Rhodia, under the trade name Miracare SLB 205.
• At least one skincare active ingredient including one or more of Oenothera Biennis (0.25% w/w), cholesterol (0.05% w/w) and Trihydroxypalmitamidohydroxypropyl myristyl ether (0.002% w/w).
• composition B was applied at least once per day for seven days and a subjective assessment made by each subject. The effect of the carrier alone on the skin was studied to determine the effect on the skin.
• Composition B (In-shower conditioner)
• composition was well-tolerated by 10 out of the 12 subjects, with minor temporary intolerance reported by two.
• the overall skin condition improved on average in terms of redness, scaliness and dryness.
• the strengths 3 of the product were found to be:
• At least one skincare active ingredient including one or more of Oenothera Biennis (0.25% w/w), cholesterol (0.05% w/w) and Trihydroxypalmitamidohydroxypropyl myristyl ether (0.002% w/w).

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