WO2007144670A1

WO2007144670A1 - Moisturising and sunscreen skincare composition

Info

Publication number: WO2007144670A1
Application number: PCT/GB2007/050333
Authority: WO
Inventors: Timm Schmidt; Ilke Apel
Original assignee: Reckitt & Colman (Overseas) Limited
Priority date: 2006-06-14
Filing date: 2007-06-13
Publication date: 2007-12-21
Also published as: EP2040667A1; GB0611743D0; GB2439618A

Abstract

A skincare composition in the form of an emulsion comprising: a) an organic sunscreen component comprising at least one sunscreen selected from the group consisting of bis-ethylhexyloxyphenol methoxyphenyl triazine and methylene bis-benzotriazolyl tetramethylbutylphenol; b) a moisturising system comprising starch or a derivative thereof and a polymeric quaternary compound salt having humectant properties; and c) a carrier comprising an oil phase, an aqueous phase and an emulsifying system, said emulsifying system comprising at least one emulsifier selected from an anionic or non-ionic emulsifier. The composition not only reduces the effect of UV radiation on the skin from UV damage, it also improves the moisturisation levels to help protect the skin from the effects of UV radiation.

Description

MOISTURISING AND SUNSCREEN SKINCARE COMPOSITION

The present invention relates to a composition for topical application which protects the skin from the effects of sunlight, in particular to a skincare composition in the form of an emulsion which provides a moisturising and sunscreen effect.

Radiation from the sun plays a major role in damaging one or more layers of the skin. For example, the heat rays have an effect in drying out the skin; also the effect of UV rays in penetrating into the deeper levels of the skin are well documented. There are different types of rays present in sunlight. UVB rays are responsible for causing sunburn where significant damage and dehydration of the skin occurs, and also may lead to skin cancers. UVA rays may also contribute to skin cancer but additionally lead to a photoageing effect where the skin loses its healthy and youthful appearance. In the dermis, the collagen and elastin fibres which provide the skin with strength, structure and elasticity, are broken down by exposure to UV radiation, leading to wrinkles and sagging skin. The UV damage may occur at any time of year as the UVA rays, which penetrate more deeply into the skin than UVB rays, pass though glass.

In addition, exposure to UV light may affect lipids in the outer layer of the skin causing the cells in the stratum corneum to adhere poorly to each other, providing that the new skin continuously being formed has an impaired skin barrier. Furthermore, destruction of the lipids, which generally form a strong protective barrier acting to preserve the moisture in the body, may also cause the skin cells to lose the water they need to stay healthy and supple. A healthy stratum corneum comprises about 30% water, giving the skin resilience and elasticity. Accordingly, it is desired to moisturise skin exposed to UV light to retain its healthy function.

Numerous products have been provided to protect the skin from the effect of exposure to the sun. These products include organic and/or inorganic sunscreens. Many of the organic sunscreens which mop up the free radicals are unstable when formulated and do not provide protection for a prolonged period. In particular, great care must be taken to minimise the amount of chosen ingredients to reduce the likelihood of the system being unstable. Significant problems can be incurred in formulating emulsions containing sunscreens and other desired ingredients to provide compositions which are capable of manufacture and are stable on storage, maintaining both the efficacy of the active and maintaining a satisfactory dispersion thereof throughout the skincare composition. If the formulation does not provide adequate protection from the sun, the epidermis is a primary location at which damage occurs. Damage to the epidermis, including dehydration, increases the damage to the lower layers of the dermis and also the intercellular matrix between the layers.

The present invention seeks to provide an improved suncare formulation. It has now been found that by providing a stable composition in which an effective sunscreen component can be combined with a particular moisturising system, advantages in the protection and overall appearance of the skin are achieved.

Patent application WO2006/061661 , published 15 June 2006, concerns a skincare composition comprising a starch (or starch derivative) and a polymeric quaternary ammonium salt having humectant properties, said composition being useful for moisturising the skin. It is disclosed that sunscreening agents are among conventional ingredients that may be incorporated in the subject composition.

However, in accordance with the present invention, there is provided an improved skincare emulsion composition which enhances the combined moisturisation and sunscreen effect on the skin of a user. It has been found that the selection of particular sunscreens formulated as an emulsion with a particular moisturising system provides advantageous protection for the skin from the effects of sunlight.

Accordingly, the present invention provides a skincare composition in the form of an emulsion comprising: a) an organic sunscreen component comprising at least one sunscreen selected from the group consisting of bis-ethylhexyloxyphenol methoxyphenyl triazine and methylene bis-benzotriazolyl tetramethylbutylphenol; b) a moisturising system comprising starch or a derivative thereof and a polymeric quaternary compound salt having humectant properties; and c) a carrier comprising an oil phase, an aqueous phase and an emulsifying system, said emulsifying system comprising at least one emulsifier selected from an anionic or non-ionic emulsifier.

The present invention has allowed the formation of a stable sunscreen system in a composition which is able to provide a continuous moisturisation effect. The emulsion can contain a relatively high proportion of water, especially up to 50% or even 60% by weight or more. The moisturisation effect of the composition may be maintained at continuous levels for a period of 12 hours or more. A continuous moisturisation effect is particularly desirable as it significantly reduces the dehydration of the skin on exposure to sunlight and maximises the rehydration and moisturisation of the skin. It has been found that a healthy skin with a properly functioning outer barrier layer exposed to the environment is better able to withstand the effects of exposure to sunlight than dehydrated, damaged skin. In particular, not only do compositions according to the invention prevent substantial moisture loss, through the continuous addition of moisture over a period of up to 12 hours or more, the epidermal layer of the skin is healthier and is better able to withstand the effects of UV radiation. Accordingly, an advantageous UV protection effect may be obtained. The compositions are advantageously used daily to maximize their effect. The compositions may be used by any person to obtain a moisturisation effect during exposure to sunlight, preferably also in advance of exposure to sunlight. A particular advantage of the present invention is that it provides a stable and effective sunscreen composition which is effective when the user has dry skin or a dry skin condition where the effect of a poorly moisturised skin can have a more marked effect on the UV damage caused to the skin. Thus, the present composition not only reduces the effect of sunlight on the skin from UV damage, it also improves the moisturisation levels to help protect the skin from the effects of UV radiation.

The skincare composition is suitable for topical application to the skin to provide a continuous moisturisation and sunscreen effect over a number of hours, ie there is a continuous and regular hydration effect to support the effect of the sunscreen component. Accordingly, the composition provides a sustained moisurisation and sunscreen effect which achieves an enhanced and persistent treatment of the skin when exposed to sunlight, especially UV radiation. The prolonged effects of the composition and constant effect of the composition is particularly valuable.

The sunscreen component useful in accordance with the present invention comprises an organic sunscreen component comprising at least one sunscreen selected from the group consisting of bis-ethylhexyloxyphenol methoxyphenyl triazine and methylene bis-benzotriazolyl tetramethylbutylphenol. These sunscreens are known as broad spectrum UV agents, but are particularly effective as UV-A sunscreens, and hence serve to reduce the effect of UV radiation on the skin. These two sunscreens have been found to be particularly effective in combination with the present moisturisation system and may be used singly or in combination.

Additional organic sunscreen agents may also be combined with said sunscreens, including p-aminobenzoic acids, esters and derivatives thereof, for example, 2-ethylhexyl p-dimethylaminobenzoate, and the octyl ester of p-aminobenzoic acid; methoxycinnamate esters such as 2-ethylhexyl p-methoxycinnamate, 2-ethoxyethyl p-methoxycinnamate, isopentenyl-4-methoxycinnamate or α,β-di-(p- methoxycinnamoyl)-α'-(2-ethylhexanoyl)-glycerin; dibenzoylmethanes such as butyl methoxydibenzoylmethane; benzophenones such as oxybenzone; 2- phenylbenzimidazole-5-sulfonic acid and disodium phenyl dibenzimidazole tetrasulfonate and terphthalylidene dicamphor sulfonic acid; alkyl-β,β- diphenylacrylates for example alkyl α-cyano-β,β-diphenylacrylates such as octocrylene; triazines such as 2,4,6-trianilino-(p-carbo-2-ethylhexyl-1 '-oxy)-1 ,3,5 triazine; camphor derivatives such as methylbenzylidene camphor; silicone derivatives such as drometrizole trisiloxane, benzylidene malonate polysiloxane and dimethicodiethyl benzal malonate and salicylates such as octyl salicylate. Preferably, maximum protection is afforded by the incorporation of at least one UV-B filter in a composition according to the present invention.

In one embodiment, the organic sunscreen component comprises bis- ethylhexyloxyphenol methoxyphenyl triazine in combination with one or more of methylene bis-benzotriazolyl tetramethylbutylphenol, ethylhexyl methoxycinnamate, isoamyl p-methoxycinnamate and butyl methoxydibenzoylmethane. In another embodiment, the sunscreen component comprises methylene bis-benzotriazolyl tetramethylbutylphenol in combination with one or more of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexylmethoxy cinnamate, isoamyl p-methoxycinnamate and butyl methoxydibenzoylmethane. Preferably, the sunscreen component comprises a combination of bis-ethylhexyloxyphenol methoxyphenyl triazine, methylene bis- benzotriazolyl tetramethylbutylphenol and ethylhexylmethoxy cinnamate, optionally including isoamyl p-methoxycinnamate.

Preferably, a composition according to the invention comprises an organic sunscreen component in an amount greater than 2.5% by weight of the composition, more preferably greater than 5% by weight and most preferably greater than 10% by weight. Further preferably, the sunscreen agent is present in the composition in an amount less than 25% by weight, more preferably less than 20% by weight and most preferably less than 15% by weight. Accordingly, in particularly preferred compositions, the sunscreen component is present in the composition in the range from 2.5% to 25% by weight, more preferably in the range from 5% to 20% by weight and most preferably in the range from 10% to 15% by weight.

Further preferably, the organic sunscreen component is present in an amount of from 15% to 60% by weight of the oil phase, more preferably from 25% to 50% by weight and most preferably from 30% to 45% by weight. If desired, a composition according to the present invention may also comprise an inorganic sunscreen agent, preferably titanium dioxide. Said inorganic sunscreen agent, if present, is preferably used in the range from 1 % to 10% by weight, more preferably in the range from 2% to 8% by weight and most preferably in the range from 3% to 7% by weight.

A composition according to the invention comprises a moisturising system comprising starch or a derivative thereof and a polymeric quaternary compound salt having humectant properties. The moisturising system reduces the effect of sunlight, including UV radiation, in dehydrating the skin. Preferably, the moisturising system is present in an amount of from 0.1 % to 16% by weight of the composition, more preferably from 1 % to 6% by weight and most preferably from 2.25% to 3.75% by weight.

The moisturising system used in accordance with present invention has a continuous effect in moisturising the skin over a period of 12 hours or more. This is particularly effective where a person may be exposed to the sun for long periods and accordingly the provision of a continuous moisturising system helps to combat the continuous dehydrating effect of the sun and to protect the skin against the effects of the sun.

The starch or starch derivative employed in the moisturing system is preferably a chemically or physically modified starch. Most preferably, the starch is modified so as to render it heat-stable and/or non-swelling. A preferred form of starch derivative is a dimethyl imidazolidinone starch derivative, ie a product obtained by reaction of 1 ,3-dimethyl-4,5-dihydroxy-2-imidazolidinone (dimethyl imidazolidinone) with starch. Particular starches that may be used include corn starch but, more preferably, the starch is rice starch. The dimethyl imidazolidinone starch derivative may thus be dimethylimidazolidinone corn starch or, more preferably, dimethylimidazolidinone rice starch.

A suitable form of dimethylimidazolidinone rice starch is available from Agrana u. Staerke AG, Conrathstr. 7, A-3950 Gmuend, Austria, under the trade name Rice NS. Another supplier is Dr Hauser, Reintalstrasse 8, D-82467 Garmisch- Partenkirchen, Germany.

The starch or starch derivative is preferably present in the composition according to the invention at a level of less than 15% by weight, preferably less than 10% by weight, and more preferably less than 5% by weight. The concentration of starch derivative is preferably greater than 0.1 % by weight, and more preferably greater than 1 % by weight. The concentration of starch derivative is therefore preferably in the range from 0.1 % to 15% by weight, and more preferably in the range from 1 % to 5% by weight, particularly in the range from 2.25% to 3.75% by weight.

The polymeric quaternary ammonium salt is most preferably the material known as Polyquaternium-51 , ie the polymeric quaternary ammonium salt that conforms generally to the formula:

A suitable form of polyquaternium-51 is available from NOF Corporation, 4-20-3, Ebisu, Shibuya-ku, Tokyo 150, Japan, under the trade name Lipidure-PMB.

The ammonium salt is preferably present in the composition according to the invention at a level of less than 1 % by weight, more preferably less than 0.1 % by weight. The concentration of ammonium salt is preferably greater than 0.0001% by weight, and more preferably greater than 0.001 % by weight. The concentration of ammonium salt is therefore preferably in the range from 0.0001 % to 1 % by weight, and more preferably in the range from 0.001 % to 0.1 % by weight.

In preferred composition according to the present invention, the ratio of moisturising system to sunscreen component is in the range 1 :1 to 1 :20 parts by weight, more preferably 1 :2 to 1 :10 parts by weight, most preferably 1 :4 to 1 :6 parts by weight.

The composition according to the invention may comprise one or more additional moisturising or humectant ingredients, ie moisturising or humectant ingredients that are additional to the starch derivative and the ammonium salt.

Most preferably, the additional moisturising or humectant ingredient is a relatively low molecular weight polyalcohol, eg a C2-6 aliphatic polyalcohol. Examples of such polyalcohols include glycerin (1 ,2,3-trihydroxypropane), 1 ,3-butylene glycol and propylene glycol. The most preferred additional moisturising or humectant ingredient is glycerin.

The additional moisturising or humectant ingredient(s) are preferably present in the composition at a level of up to 25% by weight or more, more preferably up to 20% by weight. The concentration of additional moisturising or humectant ingredient(s) is preferably greater than 1% by weight, more preferably greater than 5% by weight, and most preferably greater than 10% by weight. The concentration of additional moisturising or humectant ingredient(s) is therefore preferably in the range from 1 % to 25% by weight, and more preferably in the range from 5% to 20% by weight.

Where glycerin is present in the composition, the concentration of glycerin is preferably in the range from 1 % to 20% by weight, more preferably in the range from 10% to 20% by weight, and in particular in the range from 10% to 15% by weight. The composition may comprise more than one aliphatic polyalcohol. In some embodiments, the composition comprises both glycerin and propylene glycol.

Compositions comprising one or more aliphatic polyalcohols have been found to be particularly beneficial. In a more specific aspect, the invention thus provides a composition for topical application to the skin, which composition comprises a starch or starch derivative, a polymeric quaternary ammonium salt having humectant properties, and from 10% to 20% by weight of one or more aliphatic polyalcohols. The polyalcohols are preferably C2-6 aliphatic polyalcohols, most preferably selected from the group consisting of glycerin (1 ,2,3-trihydroxypropane), 1 ,3-butylene glycol and propylene glycol. Preferably, the composition comprises glycerin.

In preferred embodiments, the composition is free of any additional moisturising agents other than the low molecular weight polyalcohols. In particular, the composition is preferably free of sodium PCA, urea, trehalose and sodium hyaluronate.

The carrier provided in accordance with the present invention comprises an oil component and an aqueous component. Both components are required to be topically acceptable to a user, especially both cosmetically and dermatologically acceptable. The present compositions may be applied to healthy skin and to diseased skin. A composition according to the present invention is in the form of an emulsion, such as water-in-oil or oil-in-water emulsion, in which one of the phases is dispersed in the other phase with the aid of said emulsifying system. The emulsion may have an aqueous continuous phase or an oily continuous phase. Preferably, the emulsion is an oil-in-water emulsion in which the aqueous component provides the continuous phase.

The carrier provides a suitable stable topical vehicle for the sunscreen component, the moisturising component and any other desired ingredients. Elements of the carrier may be chosen so that they also have a pharmacological effect in the formulation, especially the oils. Preferably the carrier comprises at least 50% by weight of the composition, more preferably at least 65% by weight of the composition. Further preferably, the carrier comprises from 50% to 98% by weight of the composition, more preferably from 65% to 95% by weight and most preferably from 75% to 90% by weight of the composition.

In one embodiment of the invention, the organic sunscreen component is contained in the oil phase and the moisturising system is in the aqueous phase. In another embodiment of the invention, a portion of the sunscreen component is contained in the oil phase and another portion of the sunscreen component is dispersed in the aqueous phase. Conveniently, bis-ethylhexyloxyphenol methoxyphenyl triazine is contained in the oil phase. Conveniently, methylene bis- benzotriazolyl tetramethylbutylphenol is dispersed in the aqueous phase.

Preferably, the oil component comprises: hydrocarbons, silicone oils, triglycerides, waxes, glycerin, fatty acids, fatty acid alcohols and esters thereof, mineral oils, vegetable oils and hydrogenated vegetable oils, lanolin or mixtures thereof. Examples of hydrocarbons include paraffins (for example paraffinum liquidum and white soft paraffin), petrolatum, hydrogenated polyisobutene, alkyl benzoates, isohexadecane, isododecane, isononyl isonanoate, diisopropylcyclohexane; examples of silicone oils include dimethicone, cyclomethicone, cetyldimethicone or stearyl dimethicone, examples of triglycerides include natural triglycerides and synthetic or semi-synthetic triglycerides including triethylhexanoin and caprilic/capric triglyceride; examples of waxes include vegetable waxes such as carnauba wax, animal waxes such as beeswax,and mineral waxes such as paraffin wax, ozokerite; examples of esters of fatty acids or alcohols include isopropyl palmitate, isopropyl myristate, dioctylmaleate, glyceryl oleate and cetostearyl isononanoate, octyl palmitate, cetearyl alcohol, stearyl alcohol, cetyl alcohol, glyceryl Myristate, decyl cocoate:examples of mineral oils include Vaseline oil; examples of vegetable oils include jojoba oil, soy bean oil, coconut oil, sunflower seed oil, apricot kernel oil, shea butter (butyrospermum parkii), avocado oil and examples of hydrogenated vegetable oils include hydrogenated palm oil. The oil chosen for any composition may depend on the type of composition desired. The oil will be topically acceptable for cosmetic and/or dermatological use. Conveniently, the oil will have a pharmacological effect on the skin, such as providing an emollient effect. Preferred classes of oils include silicone oils, mineral oils, vegetable oils and triglycerides, especially mineral oils and vegetable oils. Particularly preferred oils are butyrospermum parkii, caprilic/capric triglyceride, C12-15 alkyl benzoate, isohexadecane, triethylhexanoin, cyclomethicone, dimethicone, cetearyl alcohol, isopropylpalmitate, stearyl alcohol, cetyl alcohol, stearyl dimethicone, glyceryl myristate, paraffinum liquidum, aluminium starch octenylsuccinate and decyl cocoate or mixtures thereof.

Especially preferred is a combination of C12-15 alkyl benzoate, caprilic/capric triglyceride, cyclomethicone and aluminium starch octenylsuccinate, optionally in combination with either isopropylpalmitate and/or isohexadecane, butyrospermum parkii.

Preferably, said oil is present in an amount in the range from 4% to 50% by weight of the composition, more preferably in the range from 6% to 30% by weight and most preferably in the range from 8% to 20% by weight.

Preferably, water is present in the composition in the range from 20% to 80% by weight of the composition, more preferably in the range from 25% to 75% by weight and most preferably in the range from 35% to 55% by weight.

Further preferably, the ratio of water to oil is in the range 10:1 to 1 :10 parts by weight, more preferably 5:1 to 1 :1 parts by weight and most preferably 5:1 to 3:1 parts by weight.

An emulsifying system useful in accordance with the present invention comprises at least one emulsifier comprising an anionic or non-ionic emulsifier. Typical representatives of these classes of emulsifiers are known to those skilled in the art. Optionally, the emulsifier may be combined with a thickening agent. A further preferred effect is achieved in accordance with the present invention by the incorporation of liquid crystal forming emulsifiers in the composition. Accordingly, in one embodiment the composition comprises an emulsifying system comprising a liquid crystal forming system. Emulsifiers that form lamellar liquid crystals are believed to mimic the multi-lamellar lipid structure of the stratum corneum which comprises corneocytes surrounded by a matrix of hydrophobic lipid membranes arranged in multiple lamellar sheets; the sheets of the lamellar membranes may have a crystal-like periodic arrangement and readily slide over one another thus keeping the stratum corneum pliant and elastic. Liquid crystals may provide advantageous skincare characteristics, for example in terms of skin penetration and hydration. It is believed that this may occur as the liquid crystals are formed into similar self-organising structure as natural stratum corneum lipids and thus show a high affinity to the skin.

Preferably, the emulsifying system comprises a combination of emulsifiers with different HLB values, more preferably at least one emulsifier with a high HLB value and at least one emulsifier with a low-medium HLB value, especially preferably at least one emulsifier with a high HLB value and at least one emulsifier with a low HLB value. Typically high HLB emulsifiers have a HLB value above 20. Typically low-medium HLB emulsifiers have a HLB below 20, for example 3-20. Preferably, the non-ionic emulsifier has a HLB value in the range 3-20. Preferably, the anionic emulsifier has a HLB value above 20. In one embodiment, the mixture of emulsifiers may comprise a combination of one or more anionic emulsifiers with one or more non-ionic emulsifiers. In another embodiment, the mixture may comprise a combination of anionic emulsifiers. In another embodiment, the mixture may comprise a combination of non-ionic emulsifiers.

The emulsifying system is preferably present in the composition in an amount in the range from 0.01 % to 20% by weight of the composition, preferably from 0.1% to 15% by weight, most preferably from 1 % to 10% by weight.

Examples of high HLB anionic emulsifiers include: methylglucose sesquistearate, sucrose cocoate, decyl glucoside, potassium stearate, sodium cetearyl sulphate, isolaureth-4 phosphate and polyglyceryl-3 methylglucose distearate. Examples of high HLB non-ionic emulsifiers include: steareth-21 , steareth-10, ceteareth-12, ceteareth-20, oleth-10, PEG-12 oleate, PEG-12 stearate or PEG-80 sorbitan. Typically, the high HLB emulsifier is present in an amount in the range 0.01 % to 10% by weight, more preferably in the range 0.1 % to 5% by weight.

Examples of low-medium HLB anionic emulsifiers include steareth-2, ceteareth-5, PEG-2 stearate and cetyl PEG/PPG/-19/1 dimethicone. Examples of low-medium HLB non-ionic emulsifiers include stearyl alcohol, sorbitan stearate, cetearyl alcohol, glyceryl stearate, polyglyceryl-3 oleate, sorbitan oleate and sorbitan palmitate. Typically, a low-medium HLB emulsifier may be present in the composition in an amount in the range 0.1% to 10% by weight, more preferably in the range 0.5% to 5% by weight.

Preferably, the emulsifiers used may be selected from one or more of sorbitan stearate, stearyl alcohol, sucrose cocoate, methyl glucose sesquistearate, cetyl phosphate, dicetylphosphate, ceteth-10 phosphate, cetearyl alcohol, glyceryl stearate, cetearyl glucoside, especially a combination of a high HLB anionic emulsifier with a low HLB non-ionic emulsifier. More preferably, the emulsifiers are selected from methylglucose sesquistearate, stearyl alcohol, sucrose cocoate, sorbitan stearate, glyceryl stearate, cetearyl glucoside and acrylates/C 10-30 alkyl acrylate cross-polymer. The combinations of methylglucose sesquistearate/stearyl alcohol or sucrose cocoate/ sorbitan stearate are particularly preferred.

Optionally other emulsifiers may also be incorporated in compositions according to the invention including steareth-2, steareth-21 , steareth-10, ceteareth-5, ceteareth-12, ceteareth-20, oleth-10, polyglyceryl-3 oleate, polyglyceryl-3 methylglucose distearate, sodium cetearyl sulphate, sodium stearate, PEG-12 Oleate, PEG-2 stearate, PEG-12 stearate, sorbitan oleate, sorbitan palmitate and cetyl PEG/PPG-10/1 dimethicone.

Suitably, thickeners include hydrophilic polymers and derivatives thereof, eg agarose, carbomer, polyacrylamide, alkyl acrylate crosspolymer, carboxymethyl hydroxyethylcellulose, hydroxyethyl cellulose, xanthan gum, cellulose gum, and hydroxypropyl starch.

Compositions in accordance with the invention may be formulated in any one of numerous different forms. Suitable types of composition, and methods by which they may be prepared, will generally be evident to those skilled in the art.

Compositions according to the invention are formulated as emulsions. The emulsions may be o/w, w/o, o/w/o or w/o/w emulsions. Preferred emulsion compositions are o/w emulsions. Such emulsion-type compositions may be described inter alia as creams or lotions. Other emulsion compositions are w/o emulsions.

As moisturisation of the skin is an important benefit of the compositions according to the invention, additional ingredients that contribute to improved skin-feel are preferably present. Such additional ingredients may include skin conditioning agents.

Suitable skin conditioning agents that may be present include ingredients having emollient properties, ie ingredients which help to maintain the soft, smooth and pliable appearance of the skin, and which function by their ability to remain on the skin surface or in the stratum corneum to act as lubricants, to reduce flaking and to improve the skin's appearance. Suitable skin conditioning ingredients will be evident to those skilled in the art, but examples include PPG-15 stearyl ether, ethylhexyl stearate, cetyl dimethicone, octyldodecanol, PPG-20 methyl glucose ether, isopropyl myristate isopropyl palmitate, isopropyl laurate isodecyl laurate, isodecyl neopentanoate, isohexadecane, pentaerythrityl tetraisostearate, caprylic/capric triglyceride, canola oil, sunflower oil (Helianthus annuus), olive oil (Olea europea), cottonseed oil (Gossypium herbaceum), jojoba oil (Simmondsia chinensis), shea butter (Butyrospermum parkii), cocoa butter (Theobroma cacao), cupuacu butter (Theobroma grandiflorum), avocado oil (Persea gratissima), evening primrose oil (Oenothera biennis), mineral oil, liquid paraffin, squalane, dimethicone, phenyl trimethicone, cyclomethicone, cyclopentasiloxane, dimethiconol and petrolatum. As noted above, one or more of these components may be present in the oil phase.

It may also be desired to include one or more skincare active ingredients according to conventional use as known by a person skilled in the art.

The composition will generally also comprise other ingredients or excipients which constitute or form part of a dermatologically acceptable carrier and will be well known to those skilled in the art. These include, for example:

a) 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. Examples of chelating agents are ethylenediamine tetraacetic acid and its salts, notably the dipotassium and especially the disodium or tetrasodium salt.

b) Preservatives - ingredients which prevent or retard microbial growth and thus protect the composition from spoilage. Examples of preservatives include DMDM hydantoin, propylparaben, methylparaben, phenoxyethanol, sodium benzoate, bronopol, sodium dehydroacetate, polyhexamethylenebiguanide hydrochloride, isothiazolone and diazolidinylurea.

c) Perfumes and colourings.

d) pH adjusting agents; and

e) Anti-oxidants.

In one embodiment of the present invention there is excluded a composition wherein the starch or starch derivative is a corn starch derivative and the polymeric quaternary ammonium salt is polyquaternium-51 , glycerin, sodium PCA, urea, trehalose and sodium hyaluronate.

In another embodiment of the invention, there is excluded surfactants which are not emulsifiers.

As described above, the compositions according to the invention are useful in that they enhance the moisturisation of the skin. Accordingly, in another aspect the invention provides methods for protecting the skin or for regulating the condition of the skin, which method comprises the topical application to the skin of a composition as herein described. In particular, the above methods protect the skin from the effects of sunlight and/or improve the appearance of the skin following exposure to sunlight. The skin to which the composition is applied will most commonly be human skin, the composition generally being applied by the user to his or her own skin. Usually, the composition will be applied to areas of skin that are normally exposed, eg the face and/or neck, the arms, hands or legs. A composition according to the invention is applied to the skin for example by rubbing or massaging into the skin, preferably before exposure to the sun for example 20-30 minutes before sun exposure.

In a yet further aspect of the invention, there is provided the use of a moisturising system comprising starch or a derivative thereof and a polymeric quaternary compound salt having humectant properties in the preparation of a skincare composition in the form of an emulsion having an emulsifying system comprising an anionic or non-ionic emulsifier and a sunscreen component comprising at least one organic sunscreen selected from the group consisting of bis- ethylhexyloxyphenol methoxyphenyl triazine and methylene bis-benzotriazolyl tetramethylbutylphenol .

The present invention also provides a process to prepare a composition as previously described comprising combining said sunscreen component (or at least one ingredient of the sunscreen component) with an oily phase and homogenously mixing with an aqueous phase. Preferably the moisturising component is incorporated in the aqueous phase, further preferably it is incorporated in the aqueous phase before combining with the oil phase. In the process, further ingredients may be incorporated into the oil phase/ aqueous phase before and/or after mixing at least one of thesunscreen components. One or more active ingredients may be added at different stages of the process. Either or both the oil and aqueous phases may be heated before being combined, for example to a temperature in the range 50-100⁰C.

In the following examples, there are described several preferred embodiments to illustrate the invention. However, it is to be understood that the invention is not to be limited to the specific embodiments.

In the examples, Methylene Bis-benzotriazolyl Tetramethylbutylphenol and Bis- Ethylhexyloxyphenol Methoxyphenyl Triazine are available from Ciba Speciality Chemicals, D-79630 Grenzach-Wyhlen, Germany, under the trade names Tinosorb M and Tinosorb S respectively; Ethylhexyl Methoxycinnamate and lsoamyl p- Methoxycinnamate are available from Symrise, D20354 Hamburg , Germany under the trade names Parsol MCX and Neo Heliopan E 1000, respectively; the Dimethylimidazolidinone Rice Starch is available from Agrana u. Staerke AG, Gmuend, Austria, under the trade name Rice NS; the Polyquaternium-51 is available from NOF Corporation, Tokyo 150, Japan, under the trade name Lipidure-PMB; the Methyl Glucose Sesquistearate is available from Degussa, Essen, Germany under the trade name Tegocare PS; the mixture of sorbitan stearate and sucose cocoate (92.5%, 7.5%) is available under the tradename Arlatone 2121 and the cetearyl glucoside is available from Degussa, Essen, Germany under the trade name Tegocare CG 90. Example 1 : Cream

Ingredient % bv weight

Glycerin 12.0 lsopropylpalmitate 5.0

C12-15 Alkyl Benzoate 4.0 lsoamyl p-Methoxycinnamate 3.75

Ethylhexyl Methoxycinnamate 3.716

Caprylic/Capric Triglyceride 3.5

Aluminium Starch Octenylsuccinate 3.0

Dimethylimidazolidinone Rice Starch 2.5

Methylene Bis-benzotriazolyl Tetramethylbutylphenol 2.5

Cyclomethicone 2.0

Methyl Glucose Sesquistearate 2.0

Stearyl alcohol 2.0

Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine 1.9

Phenoxyethanol 1.0

Parfum 0.5

Decyl Glucoside 0.45

Sodium Hydroxide 0.05

Carbomer 0.12

Propylene Glycol 0.025

Xanthan Gum 0.025

Polyquaternium-51 0.01

BHT 0.003

Water to 100%

Method

The sunscreens (excepting Methylene Bis-benzotriazolyl Tetramethylbutylphenol), the emulsifiers (Methyl Glucose Sesquistearate and stearyl alcohol) and other oily ingredients were combined to form an oil phase. The moisturising system (Dimethylimidazolidinone Rice Starch and Polyquaternium-51 ) was combined with the water and water-soluble ingredients to form an aqueous phase. The oil and water phases were independently heated to 70 -80⁰C and the oil phase admixed with the water phase. The two phases were homogenised and cooled with careful stirring. Ingredients sensitive on temperature, including Methylene Bis- benzotriazolyl Tetramethylbutylphenol, were then added to the emulsion at room temperature and the pH adjusted.

Example 2 : Cream

Ingredient % bv weight

Glycerin 12 .0

Sorbitan Stearate 5 .09 C12-15 Alkyl Benzoate 5 .0

Ethylhexyl Methoxycinnamate 7. 433

Caprylic/Capric Triglyceride 3. 0

Aluminium Starch Octenylsuccinate 3. 0

Isohexadecane 3. 0 Dimethylimidazolidinone Rice Starch 2. 5

Methylene Bis-benzotriazolyl Tetramethylbutylphenol 2. 5

Cyclomethicone 2. 0

Cetearyl Alcohol 1. 0

Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine 1. 9 Butyrospermum parkii 1. 0

Phenoxyethanol 1. 0

Parfum 0. 5

Decyl Glucoside 0. 45

Sucrose Cocoate 0. 41 Xanthan Gum 0. 125

Tocopherol 0. 1

Carbomer 0. 120

EDTA 0. 05

Sodium Hydroxide 0. 04 Propylene Glycol 0.025

Polyquaternium-51 0.01

BHT 0.007

Water to 100%

Method

The composition of Example 2 was prepared in a similar manner to that described in Example 1.

Example 3 : Cream

Ingredient % bv weiqht

Glycerin 10.53

C12-15 Alkyl Benzoate 8.0

Ethylhexyl Methoxycinnamate 4.96

Propylene Glycol 4.0

Cyclomethicone 4.0

Caprylic/Capric Triglyceride 3.5

Aluminium Starch Octenylsuccinate 3.0

Triethylhexanoin 3.0

Cetearyl Alcohol 3.0

Dimethylimidazolidinone Rice Starch 2.5

Isohexadecane 2.5

Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine 1.7

Titanium Dioxide 2.4

Methylene Bis-benzotriazolyl Tetramethylbutylphenol 1.4

Cetearyl Glucoside 1.25

Butyrospermum parkii 1.0

Phenoxyethanol 1.0

Parfum 0.5

Decyl Glucoside 0.25 lsolaureth-4 Phosphate 0.3 PEG-25 Butyl Vinylether / Sodium Maleate Copolymer 0.3

Carbomer 0.12

Tocopherol 0.1

Sodium Hydroxide 0.06

EDTA 0.05

Xanthan Gum 0.014

Polyquaternium-51 0.01

BHT 0.005

Butylmethoxydibenzoyl methane 1.5

Water to 100%

Method

The composition of Example 3 was prepared in a similar manner to that described in Example 1.

Example 4 : Cream

Ingredient % bv weiqht

Glycerin 12.0

C12-15 Alkyl Benzoate 6.0

Ethylhexyl Methoxycinnamate 4.459

Caprylic/Capric Triglyceride 3.5

Aluminium Starch Octenylsuccinate 3.0

Dimethylimidazolidinone Rice Starch 2.5

Isohexadecane 2.5

Cyclomethicone 2.0

Triethylhexanoin 2.0

Methylene Bis-benzotriazolyl Tetramethylbutylphenol 2.0

Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine 1.9

Butyrospermum parkii 1.0

Phenoxyethanol 1.0

Parfum 0.5

Decyl Glucoside 0.36 Acrylates/C 10-30 Alkyl Acrylate Crosspolymer 0.2

Carbomer 0.2

Tocopherol 0.1

EDTA 0.05

Sodium Hydroxide 0.03

Propylene Glycol 0.025

Xanthan Gum 0.02

Polyquaternium-51 0.01

BHT 0.005

Water to 100%

Method

The composition of Example 4 was prepared in a similar manner to that described in Example 1.

Example 5 : Cream

Ingredient % bv weiqht

Glycerin 12.0

C12-15 Alkyl Benzoate 6.0

Ethylhexyl Methoxycinnamate 3.996

Caprylic/Capric Triglyceride 3.5

Aluminium Starch Octenylsuccinate 3.0

Dimethylimidazolidinone Rice Starch 2.5

Cyclomethicone 2.0

Triethylhexanoin 2.0

Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine 1.7

Methylene Bis-benzotriazolyl Tetramethylbutylphenol 1.4

Butyrospermum parkii 1.0

Phenoxyethanol 1.0

Parfum 0.5

Decyl Glucoside 0.25 Acrylates/C 10-30 Alkyl Acrylate Crosspolymer 0.2 lsolaureth-4 Phosphate 0.1875

PEG-25 Butyl Vinylether / Sodium Maleate Copolymer 0.1875

Carbomer 0.18

Tocopherol 0.1

EDTA 0.05

Sodium Hydroxide 0.04

Propylene Glycol 0.014

Xanthan Gum 0.014

Polyquaternium-51 0.01

BHT 0.004

Water to 100%

Method

The composition of Example 5 was prepared in a similar manner to that described in Example 1.

Clinical Trial

The continuous moisturisation effect of Examples 1 and 2 was measured using a Standard Corneometer CM 825. The method by which moisturisation is measured is based on the dielectric constant of water. Due to the high dielectric constant of water, the dielectric characteristics of the stratum corneum are related to the water content. Assuming constant frequency, temperature and structure of the skin surface, an increase of capacitance correlates with an increase in skin hydration.

The study was conducted double blind on 30 female volunteers with dry skin. The investigation sites were localised at the inner sides of both forearms. The skin hydration was measured immediately before product application (t zero), after 2 hours , 4 hours, 6 hours , 8 hours and 12 hours. The results below represent the skin hydration relative to t zero (=1 ) and how it changes over time.

It can be seen that both formulations exhibited an advantageous continuous moisturisation profile. In addition, both formulations were deemed to provide valuable sunscreen profiles.

Claims

1. A skincare composition in the form of an emulsion comprising: a) an organic sunscreen component comprising at least one sunscreen selected from the group consisting of bis-ethylhexyloxyphenol methoxyphenyl triazine and methylene bis-benzotriazolyl tetramethylbutylphenol; b) a moisturising system comprising starch or a derivative thereof and a polymeric quaternary compound salt having humectant properties; and c) a carrier comprising an oil phase, an aqueous phase and an emulsifying system, said emulsifying system comprising at least one emulsifier selected from an anionic or non-ionic emulsifier.

2. A composition as claimed in Claim 1 , wherein the organic sunscreen component comprises bis-ethylhexyloxyphenol methoxyphenyl triazine in combination with one or more of methylene bis-benzotriazolyl tetramethylbutylphenol, ethylhexyl methoxycinnamate, isoamyl p- methoxycinnamate and butyl methoxydibenzoylmethane.

3. A composition as claimed in Claim 1 , wherein the organic sunscreen component comprises methylene bis-benzotriazolyl tetramethylbutylphenol in combination with one or more of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexylmethoxy cinnamate, isoamyl p-methoxycinnamate and butyl methoxydibenzoylmethane.

4. A composition as claimed in any preceding claim, wherein the organic sunscreen component comprises a combination of bis-ethylhexyloxyphenol methoxyphenyl triazine, methylene bis-benzotriazolyl tetramethylbutylphenol and ethylhexylmethoxy cinnamate, optionally including isoamyl p-methoxycinnamate.

5. A composition as claimed in any preceding claim, wherein the organic sunscreen component is present in the range from 5% to 20% by weight of the composition.

6. A composition according to any preceding claim further comprising an inorganic sunscreen agent.

7. A composition according to Claim 6, wherein said inorganic sunscreen agent is present in the range from 2% to 8% by weight of the composition.

8. A composition as claimed in any preceding claim, wherein the starch or starch derivative is a chemically or physically modified starch.

9. A composition as claimed in any preceding claim, wherein the starch derivative is a product obtained by reaction of 1 ,3-dimethyl-4,5-dihydroxy-2- imidazolidinone (dimethyl imidazolidinone) with starch.

10. A composition as claimed in any preceding claim, wherein the starch derivative is dimethylimidazolidinone rice starch.

11. A composition as claimed in any preceding claim, wherein the concentration of starch or starch derivative is in the range from 0.1% to 15% by weight of the composition.

12. A composition as claimed in any preceding claim, wherein the polymeric quaternary ammonium salt is Polyquaternium-51 , ie the polymeric quaternary ammonium salt that conforms generally to the formula:

13. A composition as claimed in any preceding claim, wherein the concentration of ammonium salt is in the range 0.0001% to 1 % by weight of the composition.

14. A composition as claimed in any preceding claim, wherein the ratio of moisturising system to sunscreen component is in the range 1 :1 to 1 :20 parts by weight.

15. A composition as claimed in any preceding claim, which further comprises one or more additional moisturising or humectant ingredients.

16. A composition as claimed in Claim 15, wherein the polyalcohol is selected from the group consisting of glycerin (1 ,2,3-trihydroxypropane), 1 ,3-butylene glycol and propylene glycol.

17. A composition as claimed in Claim 15 or Claim 16, wherein the concentration of additional moisturising or humectant ingredient(s) is in the range from 10% to 20% by weight of the composition.

18. A composition as claimed in any preceding claim wherein the oil comprises one or more of silicone oils, mineral oils, vegetable oils and triglycerides, preferably butyrospermum parkii, caprilic/capric triglyceride, C12-15 alkyl benzoate, isohexadecane, triethylhexanoin, cyclomethicone, dimethicone, cetearyl alcohol, isopropylpalmitate, stearyl alcohol, cetyl alcohol, stearyl dimethicone, glyceryl myristate, paraffinum liquidum, aluminium starch octenyl succinate and decyl cocoate or mixtures thereof.

19. A composition as claimed in any preceding claim wherein said oil is present in an amount in the range from 6% to 30% by weight of the composition.

20. A composition as claimed in any preceding claim, wherein the emulsifying system comprises a liquid crystal forming system.

21. A composition as claimed in any preceding claim, wherein the emulsifying system comprises at least one high HLB emulsifier and at least one low-medium HLB emulsifier.

22. A composition as claimed in Claim 21 wherein the high HLB emulsifier comprises one or more of methylglucose sesquistearate, sucrose cocoate, decyl glucoside, potassium stearate , isolaureth-4 phosphate, steareth-21 , steareth-10, ceteareth-12, ceteareth-20, oleth-10, polyglyceryl-3 methylglucose distearate, sodium cetearyl sulphate, PEG-12 oleate, PEG-12 stearate or PEG-80 sorbitan

23. A composition as claimed in either one of Claims 21 or 22 wherein the high HLB emulsifier is present in an amount in the range from 0.01 % to 10% by weight of the composition.

24. A composition as claimed in Claim 21 wherein the low-medium HLB emulsifier comprises stearyl alcohol, sorbitan stearate, cetearyl alcohol, glyceryl stearate, stearath-2, ceteareth-5, polyglyceryl-3 oleate, PEG-2 stearate , sorbitan oleate, sorbitan palmitate or cetyl PEG/PPG/-19/1 dimethicone.

25. A composition as claimed in Claim 24 wherein the low-medium emulsifier is present in the composition in an amount in the range 0.1 % to 10% by weight of the composition.

26. A composition as claimed in any preceding claim, which further comprises one or more ingredients selected from the group consisting of: a) skin conditioners; b) stabilizers; c) chelating agents; d) anti-oxidants; e) preservatives; f) perfumes and colourings; g) pH adjusting agents; and h) anti-oxidants.

27. A method for moisturising skin, which method comprises the topical application to the skin of a composition as claimed in any preceding claim.

28. A method for protecting skin against UV radiation, which method comprises the topical application to the skin of a composition as claimed in any one of claims 1 to 25.

29. Use of a composition as claimed in any one of claims 1 to 26 to protect the skin against UV radiation.

30. Use of a composition as claimed in any one of claims 1 to 26 in the manufacture of a medicament for the protection of the skin against UV radiation.

31. Use of a moisturising system comprising starch or a derivative thereof and a polymeric quaternary compound salt having humectant properties in the preparation of a skincare composition in the form of an emulsion comprising an emulsifying system comprising at least one emulsifier selected from an anionic or non-ionic emulsifier and an organic sunscreen component comprising at least one sunscreen selected from the group consisting of bis-ethylhexyloxyphenol methoxyphenyl triazine and methylene bis-benzotriazolyl tetramethylbutylphenol.

32. A process to prepare a composition as claimed in any one of claims 1 to 26 comprising combining at least one ingredient of said organic sunscreen component with an oily phase and homogenously mixing with an aqueous phase in the presence of an emulsifying system comprising at least one emulsifier selected from an anionic or non-ionic emulsifier.

33. A process according to claim 32 to form a composition, wherein bis- ethylhexyloxyphenol methoxyphenyl triazine is present in said oil phase and methylene bis-benzotriazolyl tetramethyl butylphenol is dispersed in said aqueous phase.