WO2015014818A2

WO2015014818A2 - Improved sunscreen compositions

Info

Publication number: WO2015014818A2
Application number: PCT/EP2014/066229
Authority: WO
Inventors: Jan Martin BAUMEISTER; Cloè Cibil-Le MEUDEC; Brigitte Kaiser
Original assignee: Colep Portugal, S.A.
Priority date: 2013-07-30
Filing date: 2014-07-29
Publication date: 2015-02-05
Also published as: GB201313609D0; WO2015014818A3

Abstract

There is herein described improved oil-in-water emulsion sunscreen compositions comprising UV filters, emulsifiers, carrageenan, or carrageenan-based hydro-colloidal emulsion stabilising agents, and optionally film forming polymers and methods for the preparation thereof.

Description

IMPROVED SUNSCREEN COMPOSITIONS

Field of the Invention

The present invention relates to oil-in-water sunscreen compositions having improved water-resistance and methods for the preparation thereof. More particularly, the present invention relates to oil-in-water sunscreen compositions having improved water- resistance comprising an aqueous phase and an oil phase wherein the aqueous phase includes one of more carrageenan hydro-colloidal stabilising agents and wherein the oil phase includes one or more ultraviolet (UV) filters. Background of the Invention

It is accepted that exposure to the sun, and in particular to UV rays can cause significant damage to the structure of unprotected skin, and thereby lead to an increased risk of the development of various skin cancers, such as for example basal or squamous cell cancers, or melanomas. Both the WHO and the FDA have confirmed that use of effective sunscreen products, which absorb UV radiation before it can affect the skin, can prevent such damage.

With wider public awareness of the detrimental effects of over-exposure to the sun has come an increased demand for sun protection products. It has recently been reported that in the US market alone the estimated yearly sales were in the region of $500 million with a year-on-year predicted increase of 2% p. a. In tandem with this wider understanding of the need for effective protection has come the demand for products which are able to protect various skin types, maintain effective sun-protection over increased periods of time, and also deliver effective sun-protection in response to a wider range of environmental factors than ever before. For example, it is now widely recognised that to maintain optimal protection levels from any particular aqueous sunscreen formulation it is advantageous to select a formulation suitable for the skin-type to which it in being applied, or to use a formulation designed for the level of protection desired, and to re-apply the sunscreen as necessary in accordance with the manufacturers guidance.

The effectiveness of sunscreens, and as such their ability to provide protection from sun-damage, is routinely compromised by the conditions in which they are necessarily utilised. For example, where a sunscreen is applied prior to prolonged sun exposure the skin surface is highly likely to be at a lower temperature, and indeed drier, than it will become during exposure to the sun, where the skin surface temperature is elevated as a l consequence of the heat from the sun, resulting in wetter skin from sweat, or even, where the skin surface is subjected to changes in temperature and levels of dryness due to swimming and drying-off and such like. As this sun-exposure, sweating, swimming, drying cycle may be repeated several times during the day, particularly when consumers are on holiday, the need for awareness of optimal sun-protection behaviours, and in particular re- application of product as necessary is increased. Modern sunscreens, which screen the skin from the effects of US rays, are typically high sun protection factor (SPF) formulations providing a long-term protection against harmful UV-A and UV-B irradiation with SPFs of 50 or more. In general, such high SPF formulations require significant amounts of organic UV- filters to deliver the essential levels of protection required. However, because these organic UV-filters are typically oils, their use can result in an unpleasant greasy skin feeling. Product skin-feel is an important factor in the delivery of effective sun-protection because the consumer will be more likely to use and repeat-use, as necessary, a product which is easy to use and is pleasant to apply, as opposed to a product which is less pleasant to use. To overcome this greasy skin-feel issue many sunscreen formulations are now formulated as oil-in-water emulsions, to provide a more pleasant skin feeling when applying the sunscreen formulation.

To provide efficient stabilisation of the droplets of oil (organic UV-filters) in such oil-in- water sunscreen formulations, emulsifiers have typically been utilised. A problem with such oil-in-water emulsion-based sunscreens is that, once they are dried-on or dried-into the skin, oily-films of the UV-filters on the skin are likely to be readily solubilised into water during sweating, showering, swimming or the like by residual levels of emulsifiers and, they are susceptible to being washed off and undesirably leave the skin unprotected and exposed. Film-forming polymers have been incorporated into some oil-in-water emulsion-based sunscreens to increase their water-resistance and mitigate this issue. Without being bound to any particular theory it is thought that such film-forming polymers may act akin to lacquer or glue, and reduce or prevent the amount oil (organic UV-filters) being washed away after the emulsion has been applied to and has dried in / onto the skin.

A common problem with emulsified oil-in-water sunscreen formulations which include film-forming polymers is that their residual skin-feel is often oily and moreover, the additional polymeric material in such compositions leads to increased dried-in residues on the skin, leading to an unpleasant, gritty or tightened skin feel. Significantly however, a common difficulty with such emulsified oil-in-water sunscreen formulations is that they deliver insufficient water protection levels in order to be deemed "very waterproof" according to standard Industry guidelines, such as those established by Cosmetics Europe (formerly Colipa). Given the ever-increasing demand for effective high SPF sunscreens to deliver protection to the skin throughout the anticipated environments to which the skin will be routinely exposed, elevated skin temperatures (and sweating), exposure to water (sea, chemically balanced pools, or fresh water) and dry-off, this failure to deliver protection when exposed to water is a significant issue. Thus, it would be desirable to provide effective sunscreen compositions capable of delivering effective protection from the effects of UV rays which: provide high SPF protection; are easy to apply; have desirable skin feel; are resistant to the effects of water; maintain a desirable level of protection for a suitable length of sustained exposure to the sun; are suitable for use across a variety of skin-types. In parallel with the need to develop sunscreen compositions which deliver effective protection across a range of environmental conditions and also have desirable skin-feel there is also a need for products suitable for parenteral application or other application scenarios capable of rapidly delivering sufficient product volume to the skin to enable ease- of-spread across the target area of skin to be protected. Whilst foamable sunscreen compositions may address the parenteral application aspect, to date there remains an unmet need for improved high SPF foamable sunscreens capable of providing effective protection from the sun, desirable skin feel and desirable levels of water-proofing.

Due to their gelatinous properties, seaweed extracts, carrageenans have been long- used as food additives, for thickening, gelling or stabilising products. Carrageenans are particularly used in the food industry for the stabilisation of dairy products, many of which are oil-in-water emulsions. However the utility of carrageenans within the cosmetics field to-date has been limited.

The applicant has now developed novel oil-in-water high SPF sunscreen formulations including carrageenans having improved water-resistance; skin feel characteristics; and/or skin dryness.

Whilst water-resistant sunscreen compositions are known these do not particularly relate to the use of carrageenans, for example US2011091401 (Al) relates to water- resistant sunscreen compositions and discloses water-resistant emulsions with perfluorinated emulsifier in combination with polysaccharides. Taking an alternative approach for the provision of improved water-resistance US2005186160 (Al) relates to sunscreen compositions with enhanced SPF and water resistant properties which are surfactant-free. In contrast to the oil-in-water emulsions provided herein, US2012134939 (Al) relates to water-in-oil emulsion sunscreen cosmetic compositions and discloses a water-in-oil emulsion composition having a water-soluble polymer which can be carrageenan. Sunscreen compositions having polysaccharide components are found in

WO02092041 (Al) which relates to a UV-screening and colour-changing composition and discloses a sunscreen composition having 2% of a stabiliser, which can be carrageenan, and colour-changing ingredients, and US6180090 (Bl) relates to the use of polysaccharides for improving the light protection effect of cosmetic or dermatological light protection compositions and discloses a sunscreen composition having triazine-based UV filters and polysaccharides for enhanced SPF.

None these applications disclose the oil-in-water emulsions of the present invention having carrageenan at a level of from 0.1 to 1%, or provide any teaching of any advantage for use of carrageenans per se, or for the provision of enhanced water resistance and/or enhanced skin feel in oil-in-water emulsions in particular.

It is an object of at least one aspect of the present invention to obviate or mitigate at least one or more of the aforementioned problems. It is an object of at least one aspect of the present invention to provide improved sunscreen compositions comprising carrageenan hydro-colloid.

It is an object of at least one aspect of the present invention to provide improved sunscreen compositions which have desirable water-resistance properties.

It is an object of at least one aspect of the present invention to provide improved sunscreen compositions and desirable skin feel characteristics, particularly in relation to skin-dryness.

It is an object of at least one aspect of the present invention to provide improved sunscreen compositions which have desirable water-resistance properties in combination with desirable skin feel characteristics and high SPF. It is an object of at least one further aspect of the present invention to provide improved foamable sunscreen compositions which have desirable water-resistance properties in combination with desirable skin feel and high SPF. Summary of the Invention

The Applicant has developed a novel sunscreen composition comprising:

(a) one or more UVA filter and one or more UVB filter at a total UV filter level of from 5% to 35% by weight;

(b) one or more emulsifiers at a level of from 1 % to 7% by weight;

(c) one or more carrageenan, or carrageenan-based hydro-colloidal emulsion stabilising agents at a level of from 0.1 % to 1 % by weight;

(d) water and optionally

(e) one or more film forming polymers at a level of from 1 % to 5% by weight wherein the composition is an oil-in-water emulsion and wherein at least one of the

UV filters is an oil.

Surprisingly, the applicant has found that the novel sunscreen compositions according to the present invention form stable oil-in-water emulsions which solubilise oily UV-filters with significantly reduced levels of emulsifiers, and/or film-forming polymers than the levels found in current commercial sunscreen formulations whilst still delivering excellent levels of protection, high SPF, and providing desirable skin feel properties as well as increased water-resistance versus current commercial high SPF sunscreen formulations.

Thus, according to a further aspect of the present invention there is provided oil-in- water sunscreen compositions comprising:

(i) one or more UVA filter and one or more UVB filter at a total UV filter level of from 5% to 35% by weight;

(ii) one or more emulsifiers at a level of from 1 % to 7% by weight;

(iii) one or more carrageenan, or carrageenan-based hydro-colloidal emulsion stabilising agents at a level of from 0.1 % to 1 % by weight;

(iv) water; and optionally

(v) one or more film forming polymers at a level of from 1 % to 3% by weight; wherein the relative weight ratio of UV oil components to emulsion stabilising agents is in the range between 100 : 1 and 50 : 1 and the relative ratio of UV oil components to film-forming polymers, where present, is in the range of 50: : 1 to 20: : 1 ; wherein the UV oil components are dispersed within the aqueous phase; and wherein the water soluble UV filters, where present, are in the aqueous phase.

As illustrated in the Examples, novel oil-in-water sunscreen compositions developed by the Applicant have been demonstrated to deliver improvements in water-resistance, skin feel, skin dryness, as well as providing desirable high levels of SPF protection when compared to conventional sunscreen compositions, by utilising hydro-colloids of carrageenan.

Detailed Description

The sunscreen compositions according to the invention are oil-in-water emulsions.

Sunscreen compositions as defined herein are products formulated for topical application to the skin for protection against the harmful effects of exposure to the sun. The term sunscreen as used herein includes sunblock, sun tan lotion, sun screen, sun burn cream or sun block out. The protection provided by sunscreen compositions as defined herein is absorption and, optionally reflection of some of the UV radiation from the sun.

Whilst emulsions are a particular class of colloidal systems, the terms emulsion and colloid may be interchangeably used herein in relation to the oil-in-water emulsions according to the present invention. The sunscreen compositions of the invention are oil-in- water emulsions i.e. a mixture of two immiscible liquids, oil and water, wherein the continuous/external aqueous phase and the liquid dispersed within it as separate droplets, the dispersed/internal oil phase, are both liquids. Whilst not wishing to be bound to any particular theory it is proposed herein that the sunscreen compositions according to the present invention are capable of delivering effective levels of UV protection across the skin to which they are applied due to the statistical distribution of the oil (UV filters) within the continuous aqueous phase, also known as the dispersion medium.

For the avoidance of doubt the aqueous phase in the oil-in-water emulsions according to the present invention may additionally comprise further oil- or water-soluble additives as may typically be found in sunscreen products, and as detailed hereinafter.

UV filters as defined herein include organic chemical compounds which absorb UV light, organic particulates which contain multiple chromophores, and inorganic chemical compounds which reflect UV light. Ultraviolet light may be artificially divided into three ranges: UVA is radiation in the 320-400 nm range; UVB is radiation in the 290-320 nm range; and UVC is radiation in the 100-290 nm range. As UVC is totally blocked by the ozone layer in the upper atmosphere of the Earth, blocking agents for UVC are not typical in sunscreen products. The ozone layer blocks some of the UVB, however all of the UVA passes through the ozone layer.

The sunscreen compositions according to the invention comprise filters for the effective protection of the skin against both UVA and UVB at a combined level in the range of from 5% to 35%, and preferably in the range of from 15% to 35% by weight.

UVA filters suitable for use herein include: avobenzone or butyl methoxydibenzoylmethane, also known as Parsol 1789, Parsol A, Eusolex 9020, Escalol 517, BMBM, BMDBM, and related compounds, such as for example oxybenzone; Tinosorb S also known as bis-ethyl-hexyloxyphenol methoxyphenyl triazine, BEMT, bemotrizinol, anisotriazine, Escalol S, Tinosorb S Aqua; Tinosorb M also known as methylene bis- benzotriazolyl tetramethylbutyl-phenol, MBBT, Bisoctrizole; Mexoryl SX also known as terephthalyiidene dicamphor sulfonic acid, TDSA, Ecamsuie; Mexoryl XL also known as Drometrizole trisiloxane, Ecamsuie; a combination of avobenzone and oxybenzone also known as Helioplex; Octocrylene also known as Uvinul N539T, OCR, Eusolex OCR; Oxybenzone also known as Benzophenone-3, BP3, Uvinul M40, Eusolex 4360, Escalol 567; Ensulizole also known as phenylbenzimiazole sulfonic acid, PBSA, Eusolex 232, Parsol HS; dioxybenzone also known as benzophenone-8; Meradimate also known as menthyl anthranilate; Sulisobenzone also known as benzophenone-4, BP4, uvinul MS40, Escalol 577; Disodium phenyl dibenzimidazole tetrasulfonate also known as Bisimidazylate, DPDP; Uvinal A Plus also known as diethylaminohydroxybenzoyl hexyl benzoate, DHHB; Uvasorb HEB also known as diethylhexyl butamidotriazone, DBT, Iscotrizinol. In general the UVA filter(s) suitable for use herein include both water soluble and oily UVA filters. According to a particular aspect one or more of the UVA filter(s) is an oil, more preferably the one or more UVA filter(s) are oils.

According to a further aspect of the present invention there is provided an oil-in-water sunscreen composition as detailed hereinbefore wherein one or more of the UVA filters is an oil.

UVB filters suitable for use herein include: benzyl salicylate and salicylate derivitaves, such as for example homosalate; benzyl cinnamate and cinnamate derivatives; Octinoxate also known as Octyl methoxy-cinnamate, OMC, Ethylhexyl methoxycinnamate, EHMC, Escalol 557, Parsol MCX, Eusolex 2292, Tinosorb OMC, Uvinul MC80; Octocrylene also known as Uvinul N539T, OCR, Eusolex OCR; a combination of avobenzone and oxybenzone also known as Helioplex; Tinosorb M also known as methylene bis- benzotriazolyl tetramethylbutyl-phenol, MBBT, Bisoctrizole; Tinosorb S also known as bis- ethyl-hexyloxyphenol methoxyphenyl triazine, BEMT, bemotrizinol, anisotriazine, Escalol S, Tinosorb S Aqua; Oxybenzone also known as Benzophenone-3, BP3, Uvinul M40, Eusolex 4360, Escalol 567; octisalate also known as octyl salicylate, ethylhexyl salicylate, EHS, Escalol 587; homosalate also known as homomethyl salicylate, HMS; uvinul T150 also known as octyitriazone, ethylhexyl triazone, EHT; cinoxate also known as 2-ethoxyethyl p- methoxycinnamate, Phiasol, Give Tan, Sundare; aminobenzoic acid, PABA; Padimate O also known as OD-PABA, octyldimethyl PABA, ethylhexyl dimethyl PABA, EHDP, Escalol 507; Ensulizoie also known as phenylbenzimidazole sulfonic acid, PBSA, Eusolex 232, Parsol HS; dioxybenzone also known as benzophenone-8; Sulisobenzone also known as benzophenone-4, BP4, uvinul MS40, Escalol 577; trolamine salicylate also known as trienanolamine salicylate; 4-methylbenzylidene camphor; Uvasorb HEB also known as diethylhexyl butamidotriazone, DBT, Iscotrizinol; Parsol SLX also known as dimethico- diethylbenzal-malonate, Polysilicone-15, PS15; Amiloxate also known as Isoamyl p- Methoxy-cinnamate, IMC, Neo Heliopan E1000. In general the UVB filter(s) suitable for use herein include both water soluble and oily UVB filters. According to a particular aspect one or more of the UVB filter(s) is an oil, more preferably the one or more UVB filter(s) are oils.

According to a further aspect of the present invention there is provided an oil-in-water sunscreen composition as detailed hereinbefore wherein one or more of the UVB filters is an oil.

For the avoidance of doubt many compounds are capable of filtering both UVA and UVB radiation. According to a further aspect of the present invention there is provided an oil-in-water sunscreen composition as detailed hereinbefore wherein the UVA and UVB filters are oils.

According to a further aspect of the present invention there is provided an oil-in-water sunscreen composition as detailed hereinbefore wherein the one or more UVA filters are oils and wherein the one or more UVB filters are water soluble.

Exemplary UV filters for use in the compositions according to the present invention may be independently selected from: Eusolex 9020, butyl -methoxydi benzoyl -methane (Avobenzone), UV-A-filter; Tinosorb S, bis-ethylhexyloxyphenol methoxyphenyl triazine, UV-A/B-filter (suitable for use as a UV-B filter in the formulae in Tables 1 and 2 herein); Octocrylene UV-A/B-filter (suitable for use as a UV-B filter in the formulae in Tables 1 and 2 herein); Parsol HS, phenylbenzimidazole sulphonic acid, UV-B-filter; Parsol SLX Polysilicone-15, UV-B-filter. Thus the present invention provides sunscreen formulations in accordance with any of the variations herein wherein the UVA and UVB filters are selected from: Eusolex 9020, butyl-methoxydibenzoyl-methane (Avobenzone); Tinosorb S, bis-ethylhexyloxyphenol methoxyphenyl triazine ; Octocrylene ; Parsol HS, phenylbenzimidazole sulphonic acid; Parsol SLX Polysilicone-15 and mixtures thereof.

Oil-in-water sunscreen compositions according to the present invention wherein the UV filters are oils are formulated to have a pH value in the range of from pH 4.5 to 7.5 for formulations. Oil-in-water sunscreen compositions according to the present invention wherein the UV filters comprise a mixture of water-soluble and oily UV-filters have a pH value in the range between 6.8 and 7.5.

In addition, the sunscreen compositions according to the invention may include inorganic compounds which reflect UV light at a level in the range of from 1 % to 30%, and preferably in the range of from 10% to 30% by weight and wherein the total level of UVA and UVB filters and said UV light reflecting materials is in the range of from 5% to 35%, and preferably in the range of from 15% to 35% by weight. UV reflector compounds suitable for use herein are inorganic particulates that reflect, scatter and absorb UV length and include: titanium dioxide, zinc oxide or a combination of both. Thus the present invention additionally provides a sunscreen formulation as detailed hereinbefore additionally comprising from 15% to 35% by weight of UV filters and UV light reflecting materials.

According to a further aspect the present invention additionally provides a sunscreen formulation as detailed hereinbefore additionally comprising from 15% to 35% by weight of UV filters and UV light reflecting materials and wherein said formulation is a non-aerosol formulation.

For the avoidance of doubt non-aerosol formulations as defined herein include any formulation which does not include propellants, such as for example, pump-sprays and the like. Emulsifiers, also known as emulgents, are compounds or materials consisting of both water soluble hydrophilic portions and water-insoluble, oil soluble lipophilic portions, which dual functionality provides their emulsifying effects. Typically emulsifiers are utilised to provide enhanced miscibility / stability to mixtures of liquids which would either, not normally mix, or if mixed would normally separate if left unattended. The present compositions comprise one or more emulsifiers each independently present at a level between 1 % to 7% by weight, and wherein the total level of emulsifier(s) present in the sunscreen compositions herein is in the range of from 1 % to 7%; from 1.5% to 5%; or from 2% to 4% by weight.

Emulsifiers suitable for use herein are those which are soluble in water, which are neither strongly hydrophilic, nor are strongly lipophilic but rather are well-balanced, i.e. they have an appropriate balance between their hydrophilicity and lipophilicity, their so-called HLB value. Emulsifiers having an HLB value of greater than about 14, preferably greater than about 16, more preferably greater than about 18 and especially around 20 can be used in the sunscreen compositions herein. Emulsifiers suitable for use in the sunscreen formulations according to the present invention include one or more surface active agent or surfactants. Examples of water-soluble emulsifiers for use herein include: glycerol stearate; stearic acid triethanolamine (TEA) salt; cetylated monoglycerides; polyglycerol esters; sucrose esters; diacetyl tartaric (acid) ester of monoglyceride (DATEM); sodium stearoyl lactylate (SSL); calcium stearoyl lactylate (CSL); Amphisol K (potassium cetyl phosphate) and the like; and mixtures thereof. Sunscreen compositions comprising a mixture of surfactant emulsifiers, and in particular, mixtures of 2% by weight of glycerol stearate and 2% by weight of TEA stearate have been demonstrated to provide desirable properties.

Thus according to a further aspect the present invention provides sunscreen formulations as defined herein, comprising a mixture of surfactant emulsifiers, wherein the combined level of emulsifier is in the range of 4% to 5% by weight.

Thus according to a yet further aspect the present invention provides sunscreen formulations as defined herein wherein the total level of emulsifier is 4% by weight and wherein the emulsifier is a stearate surfactant.

The Applicant has advantageously found that oil-in-water sunscreen formulations according to the present invention having desirable properties are provided where the relative ratio of UVA oil components to emulsifiers is in the range between 10 : 1 and 2 : 1 ; or between 5 :1 and 2 : 1 and the relative ratio of UV oil components to film-forming polymers is in the range of 2.5 : 1 to 50 : 1 ; or between 2.5 : 1 and 30 : 1 . As demonstrated in the examples herein oil-in-water sunscreen formulations where the relative ratio of UV oil components to emulsifiers is 2.5 :1 and the relative weight ratio of UV oil components to emulsion stabilising agents is in the range between 100 : 1 and 50 : 1 and the relative ratio of UV oil components to film-forming polymers, where present, is in the range of 50: : 1 to 20: : 1 have particularly desirable properties.

The Applicant has advantageously found that oil-in-water sunscreen formulations according to the present invention having desirable properties are provided where the relative ratio of UV components to emulsion stabilising agents is in the range between 100 : 1 to 50 : 1 and the relative ratio of UV oil components to film-forming polymers is in the range of 50: 1 to 20 : 1 have desirable properties.

Carrageenans, also known as carrageenins, are wholly natural materials which are extracted from certain species of the red seaweed, class Rhodophyceae and are generally considered to be high molecular weight linear sulphated polysaccharides having varying degrees of sulphation, whilst there are a number of structurally different carrageenans, labelled beta-, kappa-, iota-, mu-, nu-, lambda-, theta-, and xi-, of these kappa-, iota- and lambda- are more widely commercially available and are suitable for use herein. Kappa- carrageenan has one sulfate per disaccharide, iota-carrageenan has two sulfates per disaccharide and lambda carrageenan has three sulfates per disaccharide. The level of carrageenan in the sunscreen compositions herein is in the range of from 0.1 % to 1 %; in the range of from 0.2% to 0..5%; or in the range of from 0.3% to 0.5% by weight. Carrageenans suitable for use herein include commercially available forms of: iota-, kappa-, and/or lambda- carrageenan, and mixtures thereof, as well as stable sodium, potassium, magnesium and/or calcium salts of iota-, kappa- and/or lambda-carrageenan, and mixtures thereof. Suitable commercially available carrageenans for use in the improved sunscreen compositions according to the present invention include: Genuvisco® CG-131 and CG-131 ; Genugel®; refined carrageenans, such as Satiagel™ VPC and such like. Preferred for use herein are iota- and/or lambda-carrageenan and stable salts thereof. In particular sunscreen compositions comprising hydro-colloids of iota-carrageen and stable salts thereof have been demonstrated to deliver especially advantageous water-resistance properties.

According to a further aspect the present invention provides sunscreen formulations as defined herein wherein the level of carrageenan is in the range of 0.3% to 0.5% by weight. According to a yet further aspect the present invention provides sunscreen formulations having desirable water-resistance as defined herein wherein the level of carrageenan is in the range of 0.3% to 0.5% by weight and wherein said carrageenan is independently selected from: iota-carrageenan; iota-carrageenan in the form of an Na, K or Ca salt; a mixture of iota-carrageenan and its salts; iota-carrageenan in the form of an Na- salt; iota-carrageenan as detailed hereinbefore at a level of 0.3% by weight.

The Applicant has advantageously found that oil-in-water sunscreen formulations according to the present invention having desirable properties are provided where the relative ratio of UVA oil components to emulsifiers is in the range between 5 : 1 and 1 : 1 ; or between 2 :1 and 1.2 : 1 and the relative ratio of UVA oil components to carrageenan is in the range of 25: : 1 to 10 : 1. As demonstrated in the examples herein oil-in-water sunscreen formulations where the relative ratio of UVA oil components to emulsifiers is 2.5 : 1 and the relative ratio of UVA oil components to carrageen is in the range of 18: 1 to 15 : 1 have particularly desirable properties. As indicated hereinbefore the novel sunscreen compositions according to the present invention form oil-in-water emulsions which solubilise oily UV-filters. Such compositions deliver excellent levels of protection, high SPF, and provide desirable skin feel properties as well as increased water-resistance versus current commercial high SPF sunscreen formulations. Without wishing to be bound to any particular theory it is thought that this surprising increase in water-resistance of topically applied sunscreen compositions according to the invention, when compared to other hydrocolloids or traditional sunscreen formulations (which can comprise higher levels emulsifiers and/or film-forming polymers) may be related to the unique solubility properties of carrageenans, and in particular their ready solubility in hot aqueous solution, for example sweat or perspiration, which it is believed may then enable combination of the carrageenans with multi-valent ions present in sweat or perspiration to provide poorly soluble salts.

As illustrated in the Experimental results section hereinafter the Applicant has found that sunscreen composition having varying desirable levels of water-resistance can be formulated with varying salt forms of carrageen, particularly the sodium salt of iota- carrageenan.

Film-forming polymers suitable for use herein are polymeric materials which mitigate the effects or water and/or reduce the amount of UV filters which are washed off, or sweated off the skin. The sunscreen compositions of the present invention include one or more film forming polymers at a level of from about 1 % to 5%, from 2% to 4%, from 2.5% to 3.5% by weight. Examples of the one or more film-forming polymers suitable for use in the compositions according to the present invention include: trimethylpentanediol/adipic acid/glycerin cross polymer (Lexorez® 200); polyacrylic acid; polycrotonic acid; polymethacrylic acid; polymaleic acid; polyitaconic acid; octylacrylamide/acrylates/butylaminoethyl methacrylate copolymer; acrylates/octylacrylamide copolymer; acrylates copolymer; octylacrylamide/butylaminoethyl methacrylate copolymer; VA crotonates/vinyl neodecanoate copolymer; VA Crotonates copolymer; sodium polystyrene sulfonate; polyurethane-14 (and) AMP-Acrylates copolymer; acrylates/octylacrylamide copolymer; acrylates/steareth-20 itaconate, copolymer; acrylates/ceteth-20 itaconate copolymer; PVM/MA half ethyl ester copolymer; butylated PVP; PVP/hexadecene copolymer; PVP/eicosene copolymer; tricontanyl PVP; butyl ester of PVM/MA copolymer; PVM/MA copolymer; ethyl ester of PVM/MA copolymer; butyl ester of PVM/MA copolymer; vinyl caprolactam/PVP/dimethylaminoethyl methacrylate copolymer; polyquaternium-1 1 ; polyquaternium-28; Polyimide-1 ; PVP/Vinylcaprolactam/DMAPA Acrylates Copolymer; Isobutylene/Ethylmaleimide/Hydroxyethylmaleimide Copolymer; Acrylates/CI-2 Succinates/Hydroxyacrylates Copolymer; PVP/DMAPA Acrylates Copolymer; VP/Acrylates/Lauryl Methacrylate Copolymer; Polyquaternium-55;

PVP/Dimethylaminoethylmethacrylate Copolymer; VinylcaprolactamNP/Dimethylaminoethyl Methacrylate Copolymer; VA/Butyl Maleate/lsobornyl Acrylate Copolymer; acrylic acid/ethyl acrylate/t-butyl acrylamide; t-butyl acrylate/ethyl acrylate/methacrylic acid; ethyl acrylate/t- butyl acrylate/methacrylic acid; polyquaternium-16; PVP; PVPNA copolymer; Polyurethane- 1 ; VP/MethacrylamideNinyl Imidazole Copolymer; Acrylates Copolymer; Acrylates/Acrylamide Copolymer; Polyvinylcaprolactam; Dimethicone/Acrylates Copolymer; Amerchol; acrylic acid/methacrylic acid/acrylates/methacrylates; acrylic acid/methacrylic acid/acrylates/methacrylates/hydroxy ester acrylates; methacryloyl ethyl betaine/acrylates copolymer; Acrylates/Hydroxyesters; Ethylenecarboxyamide/AMPSA/Methacrylates Copolymer; methacrylic acid/sodium acrylamidomethyl propane sulfonate copolymer; AMP- Acrylates/Allyl Methacrylate Copolymer; Polyacrylates-X; Acrylates/C 10-30 AlkyI Acrylates Copolymer; Polyurethane-2; Polyurethane-4; PPG-17/IPDI/DMPA Copolymer; polyethylene glycol; water-soluble acrylics; water-soluble polyesters; polyacrylamides; polyamines; polyquaternary amines; styrene maleic anhydride (SMA) resin; or mixtures or combinations thereof. Sunscreen compositions comprising a film-forming trimethylpentanediol/adipic acid/glycerin crosspolymer, Lexorez® 200, and in particular, Lexorez® 200 at 2% by weight have been demonstrated to provide desirable stability and water-resistance properties.

Thus according to a further aspect the present invention provides sunscreen formulations as defined herein comprising a film-forming polymer at a level of from 1 % to 5%, wherein said film-forming polymer is preferably present at 2% to 4% by weight, and wherein said film-forming polymer is a trimethylpentanediol/adipic acid/glycerin crosspolymer. Thus according to a yet further aspect the present invention provides sunscreen formulations as defined herein wherein the total level of film-forming polymer is 2% to 4%, preferably from 2.5% to 3.5% by weight and wherein said polymer is Lexorez® 200.

The Applicant has also found that the improved sunscreen compositions according to the present invention, which have desirable water-resistance properties in combination with desirable skin feel and high SPF, can be formulated as stable foamable, stable foaming, or stable foamed products such as mousses via the inclusion of one or more additional foam- boosting agents at a level of from 0.5% to 2%, and preferably at 1 % by weight, wherein said foam-boosting agents are amphoteric surfactants, so-called amphoterics. Suitable amphoteric foam-boosting agents for use herein are surfactants having an ionic charge which can change between anionic character, the isoelectric neutral stage, and the cationic character and include amphoterics having one ionic group, and betaine (Ν,Ν,Ν- trimethylglycine) and betaine-derivatives which are amphoterics having a fully quaternatrized nitrogen and present in the form of zwitterions. Betaines for use herein include: alkyl derivatives of betaine, alkyl betaines, wherein one methyl group is replaced by a long alkyl chain derived from coconut oil, or palm kernel oil (C₈-C₁₈), tallow (C₁₆-C₁₈ and C₁₈ ), palm oil (C₁₆-C₁₈ and C₁₈ ), or pure C₁₂-chain; alkylamido derivatives of betaine, alkylamido betaines of the general formula R-amidopropyl betaine wherein R is -cocoalkyl, mixed -coco/- oleoalkyl, or a pure -Ci₂-derivative; hydroxysulpho-betaines of general formula R- hydroxysulphobetaine wherein R is -cocoalkyl and synthetic Ci₄-Ci₅ alkyl structures in aqueous solutions with NaCI. Any commercially available amphoteric foam-boosting agent may be used, further examples of such materials include alkyl amphoterics, polycarboxyglycinates and the like.

As illustrated in the Experimental results hereinafter use of cocamidopropylbetaine (Dehyton® K) provides, foamable, oil-in-water, sunscreen compositions suitable for delivery as mousse products having: high SPF; highly desirable levels of water-resistance; desirable skin-feel properties.

Thus according to a yet further aspect the present invention provides sunscreen formulations as defined herein additionally comprising one or more amphoteric surfactant foam boosting agents at a level of from 0.5% to 2%, from 0.6% to 1.6%, from 0.8% to 1.2% by weight. According to a yet further still aspect the present invention provides sunscreen formulations as defined herein additionally comprising an alkylamidobetaine foam boosting agent at a level of 0.5%% to 2% by weight.

As detailed hereinafter the sunscreen formulations as defined herein can be formulated as stable foamable products. Surprisingly the Applicant has found that the foams provided by said formulations are exceptionally stable over time, after or on and/or after dispensing, providing foams which remain stable for greater than 3 minutes; greater than 5 minutes; greater than 10 minutes. A stable foam as defined herein means a foam which to the naked eye does not lose its exterior shape or foamed appearance within the defined time frames indicated herein. Foamable sunscreen formulations according to the present invention have been demonstrated to provide foams which remain stable for up to 30 minutes.

Thus the present invention additionally provides foamable oil-in-water sunscreen compositions comprising:

(ii) one or more emulsifiers at a level of from 1 % to 7% by weight;

(iv) one or more amphoteric surfactant foam boosting agents at a level of from 0.5% to 2% by weight.

(v) water; and optionally

one or more film forming polymers at a level of from 1 % to 3% by weight; wherein the relative weight ratio of UV oil components to emulsion stabilising agents is in the range between 100 : 1 and 50 : 1 and the relative ratio of UV oil components to film-forming polymers, where present, is in the range of 50: : 1 to 20: : 1 ; wherein the UV oil components are dispersed within the aqueous phase; and wherein the water soluble UV filters, where present, are in the aqueous phase.

In addition to their demonstrated advantageous water-resistance foaming, foamable, or foamed sunscreen compositions according to this yet further aspect of the present invention deliver highly desirable product application advantages including: stable foams; ease-of foam-breaking; non-drip formulations (even in warm environments); more even distribution of UV-filters across the skin. It is believed that the thixotropic properties of carrageenans are related to the ability of the mousse formulations according to this yet further aspect of invention to form stable foams.

Ease of foam breaking as defined herein means foams which are readily broken down and are therefore readily spreadable, thereby providing more rapid skin-coverage.

As discussed herein before the sunscreen formulations according to the present invention may additionally comprise additional agents as are typically found in sunscreen formulations such as for example: perfumes or fragrances, preservatives, antibacterial components, colouring agents, chelating agents such as EDTA and salts thereof, soothing agents such as Allantoin or tocopherol, and such like. These additional agents may each be independently present at levels in the range of from 0.01 % to 1 % by weight, and the total level of additional agents present in the sunscreen formulations according to the present invention is in the range of from 0.01 % to 5% by weight. For the avoidance of doubt, where the actual or relative amounts of water in any particular composition according to the invention described herein are not specified it should be understood that the actual or relative amount of water required will be that sufficient to reach 100% of composition, either by weight or relative volume. Water may be used in any form suitable for inclusion into consumer products including: purified, de-ionised or distilled form, or from regular supply.

The oil-in-water sunscreen compositions according to the invention can be dispensed as liquids, pump sprays, pump foams and foams and may preferably be dispersed as aerosol sprays and/or mousses. Thus according to a yet further aspect the present invention provides a sunscreen product comprising a sunscreen composition as defined herein wherein said composition is dispersed as a liquid, pump spray, foam, aerosol spray, or mousse.

Where aerosol spray or mousse compositions are formulated the composition additionally comprises a propellant at a level of from 5% to 15% by weight, from 7% to 12%, 10% by weight. When formulating a propellant formulation the % weight of propellant is by weight of the final propellant containing composition. For the avoidance of doubt the relative weight ratios of the non-propellant components are relative to each other, whilst the propellant ratio is relative to the final composition i.e. to formulate Formula 1 in table 1 as an aerosol containing 10% of propellant, formula 1 would comprise 90% of the final formulation. Any suitable commercial propellant may be used. Suitable propellants for use herein include: liquefied petroleum gases like for example propane and butane, dimethyl ether; compressed air; compressed nitrogen; soluble compressed gases such as for example, C0₂ or mixtures thereof.

Thus the present invention additionally provides a sunscreen composition formulated as an aerosol or mouse product comprising:

(ii) one or more emulsifiers at a level of from 1 % to 7% by weight;

(iv) water; and optionally

(v) one or more film forming polymers at a level of from 1 % to 3% by weight; and/or one or more amphoteric surfactant foam boosting agents at a level of from 0.5% to 2% by weight. wherein the relative weight ratio of UV oil components to emulsion stabilising agents is in the range between 100 : 1 and 50 : 1 and the relative ratio of UV oil components to film-forming polymers, where present, is in the range of 50: : 1 to 20: : 1 ; wherein the UV oil components are dispersed within the aqueous phase; wherein the water soluble UV filters, where present, are in the aqueous phase, and wherein a propellant is present at a relative level of from 5% to 15% by weight versus the total weight of the sunscreen composition.

The novel sunscreen formulations according to the invention may additionally be formulated for dispension from pump foam dispensers. Such non-aerosol pump products may include a compress pack such as for example a bag-on-valve or tin plate systems both of which are commercially available technologies.

According to a further aspect the present invention provides a sunscreen product comprising a sunscreen composition as defined herein wherein said composition is provided within a bag within a bag-on-valve packaging system to allow 360° application of the composition to the skin.

Sun protection factor (SPF) is a worldwide standard for measuring the effectiveness of a sunscreen, levels of protection from UV radiation, when applied at an even rate of 2 milligrams per square centimeter (mg/cm²). Essentially the SPF rating is a multiplier that tells how long one can safely remain in the sun. For example, if an individual whose unprotected skin becomes sunburned in 5 minutes, then an SPF-15 sunscreen should allow that individual to stay in the sun for 15 times 5 minutes, or 75 minutes, without burning. As detailed in the Experimental results hereinafter sunscreen compositions according to the present invention have been demonstrated to deliver high levels of SPF protection. In the EU high SPF levels are SPFs in excess of about SPF-30, more particularly in excess of about SPF-50, which are typically labeled as SPF50⁺. Other jurisdictions may allow labeling levels of up to about SPF-70. According to a further aspect the present invention additionally provides novel and inventive methods for the preparation of the novel and inventive sunscreen formulations as detailed herein, both in the form or aerosol and non-aerosol compositions. Such methods are detailed hereinafter in the Process Examples. Thus the present invention provides a method for the preparation of an oil-in-water sunscreen formulation with water-soluble and oily UV filters comprising:

(a) Preparation of an aqueous phase comprising water soluble UV filter(s);

(b) Neutralisation of the aqueous phase to between pH 6.8 to 7.5 followed by addition of carrageenan and subsequent heating to a temperature of between 80°C to 85°C ; (c) Preparation of an oil phase comprising one or more emulsifiers and oily UV filter(s and heating to a temperature of between 80°C to 85°C; and

(d) Emulsification of the oil phase into the aqueous gel phase followed by cooling;

(e) Addition of foam booster and other optional additional components followed by optional pH adjustment.

According to a yet further aspect the present invention provides a method for the preparation of foamable oil-in-water sunscreen formulations including a propellant.

Thus the present invention provides a method for the preparation of foamable oil-in-water sunscreen formulations with water-soluble and oily UV filters comprising:

(a) Preparation of an aqueous phase optionally comprising water soluble UV filter(s); (b) Optional neutralisation of the aqueous phase to between pH 6.8 to 7.5, followed by addition of carrageenan and subsequent heating to a temperature of between 80°C to 85°C ;

(c) Preparation of an oil phase comprising one or more emulsifiers and oily UV filter(s and heating to a temperature of between 80°C to 85°C;

(e) Addition of foam booster and other optional additional components; and

(f) Addition of propellant(s) at a level of from 5% to 15% by weight under suitable conditions, and optional pH adjustment to between 6.8 and 7.5 if optional water- soluble UV filters.

For the avoidance of doubt, the UVA and UVB filter components, the carrageenan, the emulsifiers, the foam boosters, the other optional additional components, and the pH adjusting agents, for use in accordance with the method of the invention are as generally defined herein before, and as specifically defined in the Claims hereinafter, and as particularly detailed in the Examples herein.

Detailed Description - Experimental Methods The various physical properties of the compositions exemplified can be measured according to any of the standard methodologies as are known in the art. For example, the SPF of a test product can be measured in vivo by determining the point at which the skin of fair-skinned volunteers becomes sunburned when exposed to a suitable artificial light source. Alternatively the SPF may be measured in vitro using a spectrometer to determine the transmittance of the sunscreen and the degradation of the product. Such methods are well-known in the field of sunscreens and are described in Allen et. al. Thermo Fisher Scientific, Application Note: 51463.

To determine the SPF protection level of a sunscreen composition the common

International Sun Protection Factor (SPF) test method (2006) agreed between JCIA, CTFA- SA and COLIPA, available at: https://www.cosmeticseurope.eu/downloads/86.html can be used. In brief this method requires that an unprotected area of each subject's skin, in a test area of the back between the waist and shoulder-line, be exposed to UV light and a test sun protection product be applied to a different area of skin (in the test area) with subsequent exposure to UV light. A further area of skin (in the test area) is exposed to UV light following application of a reference SPF sunscreen formulation. A xenon art lamp solar simulator (or equivalent) of defined and known output is used to provide the UV light source. By incrementally increasing the UV dose, varying degrees of skin erythema are generated which are visually assessed for redness intensity 16 to 24 hours post-UV exposure, using the judgement of a trained evaluator. The minimum erythemal dose (MED) for unprotected skin of an individual (MEDui) and the MED post-application of a test sunscreen formulation on an individual (MEDpi) must be determined on the same subject on the same day. More than one test product may be tested on the same subject in any single test. The individual sun protection factor (SPFi) for each subject tested is provides as the ration of MEDpi/MEDui and the SPF for the any test product is the arithmetic mean of all valid SPFi results from each and every subject in the test. A minimum of 10 valid results and a maximum of 20 are recommended for calculation of SPF values.

The present UV protective factor studies were performed in accordance with the Recommendation of the Commission of the European Communities of 22 September 2006 on the efficacy of sunscreen products and the claims made relating thereto (document number C(2006) 4089, 2006/647/EC) as discussed hereinbefore. Sunscreen products should be sufficiently effective against UVB and UVA radiation to provide a high level of health protection. For this purpose, a sunscreen product should provide the minimum UVB and UVA protection. Protection against UVA and UVB radiation should be interconnected. Scientific findings show that some of the biological damage to the skin can be prevented or reduced if the level of SPF measured in the persistent pigment darkening test (i.e. fighting mainly UVA radiation) is at least 1/3 of the factor measured by the sunscreen test (i.e. fighting mainly UVB radiation). Additionally, in order to provide comprehensive protection, dermatologists recommend a critical wavelength of at least 370nm.

In the experiments carried out by the Applicant for the determination of MED, SPF, or PPD a UV TH - 1 lamp was used containing UVA radiant with a wavelength spectrum of between 320 and 400 nm, a peak emission of 370 nm, and a UVB wavelength spectrum of between 280 and 320 nm. In accordance with general guidelines MED is representative of the minimal erythema dose which causes a distinct erythema after 24 hours.

Detailed experimental method for determination of MED: MED (minimal erythema dose) was measured in each of the 15 test subjects prior to the determination of the protective factor of the sunscreen product(s) to be tested. One cm² skin areas that are usually not subject to irradiation (the back) were irradiated with a UV lamp with various increasing doses of UVB 0.01 J/cm², 0.02J/cm², up to 0.1 J/cm². The MED was recorded as the lowest dose of UVB radiation which caused a erythematous reaction, usually after 2 hours, which remained after 24 hours and which produced melanosis after 48 hours. The average UVB/MEDs determined in these laboratory tests was between 0.06 and O.U/crm² for persons with skin types 1 to 3. In an analogous manner, the average UVA MEDs were determined to be between 7 to 10J/cm². Detailed experimental method for determination of SPF: In order to determine the SPF (UVB), persistent pigment darkening (PPD) against UVB/UVA rays, studies were performed on 15 subjects of different skin types ranging in age between 22 to 60 years, after a prior assessment of the subject's skin by a dermatologist in order to exclude possible lesions, which would prevent the proper conduct of the study or its correct interpretation. The determination was consistent with the principles of COLIPA. The tested product - "BK - 31 - 6" was applied onto 1 cm² skin areas of the back (2 mg/cm²), and next to it the control COLIPA - P2 sample was applied at the same dosage volume. After 10 minutes, the skin areas on the volunteers, having test/control products thereon, were irradiated with increasing doses of UVB and UVA, which were the multiple MED for each volunteer. The increase in dose was 1 MED. The standard range of radiation doses ranged from 1— 10, 1 1— 20, 21— 30, 31 - 40, 41 - 50, 51 - 60, and 60 - 65 MED. Erythema was assessed after 2, 24, 48 and 72 hours respectively.

In the EU the relative ratio of the level of protection against PDD for UVA has to be 1/3 of the level of protection against UVB / SPF. Other ratios apply in other jurisdictions.

Resistance to water immersion and sweating is also an important aspect of a sunscreen performance. In the USA this is measured in vivo, by the ability of a product to withstand water immersion. SPF has to remain unchanged after two twenty-minute immersions for a "water resistant" product. A "very water resistant" product will offer the same protection after four twenty-minutes immersions. Each 20 minute immersion interval is followed by a 20 minute rest/air dry period until the total water exposure time is reached. In Europe, the SPF after a 40 and 80 minute water immersion period is measured and compared to the original SPF before water exposure. A product is considered "water resistant" or "extra water resistant" if the SPF data after 40 or 80 minute immersions respectively is greater or equal to 50% of the pre-immersion SPF. In Europe the SPF number on the product label products is pre-water exposure while in the USA the SPF on the label corresponds to the measurements after the water immersion cycles. To determine the water-resistance of a sunscreen composition the following method using the guidelines for the Evaluation of Sun Product Water Resistance provided by the European Cosmetic Toiletry and Perfumery Association (COLIPA) in 2005, available at: https://www.cosmeticseurope.eu/downloads/88.html may be used. Essentially the water resistance test compares the SPC of a test product following a period of immersion in water with the original, static SPF of said test product determined using the COLIPA 2006 SPF method described hereinbefore. To determine the wet SPF (SPFw), the International SPF test method is followed up until the point where the product under test has been applied to the individual volunteer's skin, after which the water resistance can be assessed by: allowing 15 to 30 minutes drying time post-product application; immersing the test area in water for 20 minutes; leaving the area to dry for 15 minutes (without towelling); immersing the test area in water for a further 20 minutes; leaving the area to dry for 15 minutes (without towelling); the SPF of the so-treated skin is then measured (SPFw) which can then be compared with the static SPF to provide an assessment of water-resistance.

Process Examples

Preparation of an oil-in-water formulation with water-soluble and oily UV filters.

The water soluble UV filter(s) are added to water (aqueous phase) followed by neutralisation to between pH 6.8 to 7.5 with aqueous triethylamine or NaOH with subsequent addition of carrageenan with stirring to provide a homogeneous aqueous gel phase. Separately the oil phase comprising one or more emulsifiers and the oily UV filter(s) is prepared. Each phase is separately heated to a temperature of between 80°C to 85°C after which the oil phase is emulsified into the aqueous gel phase with continuous stirring. The mixture is cooled to 30°C or room temperature, preferably about 30 °C using a cold water jacket with continued stirring and the foam booster and other optional additional components, such as film forming polymers and additional agents as are typically found in sunscreen formulations are added. If necessary, the pH of the final sunscreen formulation is adjusted to between 6.8 and 7.5 as indicated hereinbefore.

Formulations prepared according to this method are suitable for direct application, such as for example as creams or lotions.

Preparation of a foamable oil-in-water sunscreen formulation including a propellant.

The base adjusted sunscreen formulation is prepared in accordance with the method above and then suitable propellant(s) are added at from 5% to 15% by weight under suitable conditions and packaged accordingly. If necessary the pH of the foam- booster containing sunscreen formulation is adjusted to between 6.8 and 7.5 as detailed hereinbefore depending upon whether water-soluble UV filters are present.

Formulations prepared according to this method are suitable for application as aerosols or mousses.

To prepare sunscreen formulations with only oily UV filter the above methods are used with adjustment to a pH in the range of between 4.5 to 7.5 as may be necessary using triethylamine or NaOH as detailed hereinbefore.

The following non-limiting examples are representative of the sunscreen compositions according to the invention.

Example Compositions 1 to 12

Compositions 1 to 4, as detailed in Table 1 , are representative of the compositions according to the present invention and may be made according to the processes indicated hereinbefore.

Compositions 5 to 12, as detailed in Table 2 are comparator formulations which comprise equivalent levels of UV-filters to compositions 1 to 4.

All components are expressed as % of total sunscreen composition for example 1 % of Versan® soft means that there is 1 part by weight of Versan® soft per 100 parts by weight (100%) of the complete composition.

Table 1

Film-forming polymer, 2 2 2 2

trimethylpentanediol/adipic

acid/glycerin crosspolymer³

Foam-booster, coca- 1 1

mamidopropylbetaine⁴

Water (to 100 parts) to 100 to 100 to 100 to 100

¹ commercially available as Genuvisco® CG-131 from CP Kelco

² commercially available as Genuvisco® CG-129 from CP Kelco

³ commercially available as Lexorez® 200 from Inolex Chemical Company

⁴ commercially available as Dehyton® K from Cognis

Table 2

⁵ commercially available as Velsan^® soft, from Clariant

⁶ commercially available as LaraCare™, (arabinogalactan) from Lonza ⁷ commercially available as Keltrol® CG-SFT, from CP Kelco

Example Compositions 13 to 15

Compositions 13 (SP F 30), 14 (SPF 30), and 15 (SPF 50), as detailed in Table 3, are representative of mousse compositions according to the present invention and may be made according to the processes indicated hereinbefore.

All components are expressed as % of total sunscreen composition for example 1 % of Versan® soft means that there is 1 part by weight of Versan® soft per 100 parts by weight (100%) of the complete composition, and as target weight in g out of a 1 kg or 12Kg batch as indicated.

Table 3

D Parasol SLX, Polysilicone-15, UV filter - - - - 3.00 360

F Euxyl PE9010, Phenoxyethanol, 1.00 10 1.00 10 1.00 120 ethyhexyl glycerin, UV filter

G Dehyton K, Cocoamidopropyl betaine 1.00 10 1.00 10 1.00 120

H TEA, Triethanolamine (QS pH 6.8 - 7.0)

100 1000 100 1000 100 12,000

The compositions of Examples 13 to 15 are prepared as follows: A: Water is placed in the main formulation vessel and parasol HS is added with neutralisation under continuous stirring until it is soluble and has a pH of 6.4 to 6.8; B Carageenan is added with stirring until a homogeneous gel is obtained and the formulation vessel is then heated to about 80 to 85°C. The components in phase D of Table 3 are mixed together in a separate vessel and heated to a temperature of about 80 to 85°C, and then this heated mixture of components is added into the homogeneous gel phase in the main formulation vessel. Triethanolamine is then added to the stirred mixture, and stirring is continued for a further 10 minutes, at 80°C, followed by cooling to

30°C using a water-jacket or such like, with continuous stirring. Stirring is continued for the addition of the Euxyl PE9010, followed by the Dehyton K. The pH is then adjusted to from about 6.8 to 7.0 if necessary, using TEA.

Experimental Results

As illustrated in Table 4, sunscreen compositions according to the invention, Examples 2 to 4, have desirable high SPF protection levels, and desirable skin-feel properties. In addition to the required high SPF protection necessary to demonstrate effectiveness as a potential sunscreen, it is highly desirable that the sunscreen compositions of the invention additionally demonstrate water-resistance.

As also illustrated in Table 4, compositions according to the invention display desirable water-resistance properties. All the test formulations were subjected to a common water-resistance testing method. To assess the relative water-resistance properties of test formulations the following method may be used: measure a common amount of a test formulation and carefully place onto a glass slide using a pipette, or a spatula, and distribute evenly over said slide (avoiding the edges); repeat for further test and comparator formulations as necessary; allow the slides to dry overnight at room temperature (RT), or in an oven at 26°C; weigh each slide and leave to dry for a further hour and re-weigh to confirm dried-weights; prepare solutions of demineralised water in separate 150ml glass beakers with a sufficient volume of water to fully immerse the formulation containing portions of each test slide; carefully immerse each test slide in an individual beaker without agitation or stirring and leave for 20 minutes; remove slides carefully and leave to dry overnight at room temperature (RT), or in an oven at 26°C; weigh each slide and leave to dry for a further hour and re-weigh to confirm dried-weights; calculate the percentage weight of each formulation removed by the water to provide comparative water-resistance measurements. Visual checks of the relative turbidity the solution remaining in of each beaker may be also be used in this assessment as a rough guideline of relative water resistance. Table 4 illustrates the advantageous properties of foamable spray products made in accordance with the method provided herein which include 10% of propellant in addition the components indicated in Examples 1 to 4.

TABLE 4

¹ Assessed by measuring the weight loss from an immersion test. ^x water-proof

^Y very water-proof All the example compositions demonstrated excellent water-resistance properties overall and in particular the foam compositions 2 and 4 which additionally include a betaine foam boosting agent demonstrated enhanced water-resistance.

Additional experiments have confirmed that non-aerosolised emulsions i.e. example compositions 1 to 4 and 13 to 15 herein, display desirable mousse stability properties with foam stabilities in excess of 10 minutes as well as excellent bulk stability properties of up to 4 weeks stability at 42°C. Further studies have confirmed that propellent-containing aerosol compositions according to the invention have bulk stabilities at 42°C of greater than 4 weeks. Whilst specific embodiments of the present invention have been described above, it will be appreciated that departures from the described embodiments may still fall within the scope of the present invention. For example, any suitable type of UVA and UVB filters may be used. Moreover, any type of iota-carrageenan may be used.

Claims

1. A sunscreen composition comprising:

(a) one or more UVA filters and one or more UVB filters at a total UV filter level of from 5% to 35% by weight;

(b) one or more emulsifiers at a level of from 1 % to 7% by weight;

(d) water; and optionally

(e) one or more film forming polymers at a level of from 1 % to 5% by weight wherein the composition is an oil-in-water emulsion and wherein the composition is an oil-in-water emulsion and wherein at least one of the UV filters is an oil.

2. A sunscreen composition according to claim 1 , wherein the relative ratio of UVA oil components to emulsifiers is in the range of from 10 : 1 to 2 : 1 and the relative ration of UVA oil components to film-forming polymers is in the range of from 2.5 : 1 to 50 : 1 and wherein the UVA oil components are dispersed within the aqueous phase.

3. A sunscreen composition according to any of claims 1 or 2, wherein the level of

carrageenan is in the range of 0.2% to 0.5% by weight.

4. A sunscreen composition according to any preceding claim, wherein the carrageenan is independently selected from: iota-carrageenan and salts thereof; lambda- carrageenan and salts thereof; and mixtures of iota-, and lambda-carrageenan and salts thereof.

5. A sunscreen composition according to any preceding claim, wherein the carrageenan is iota-carrageenan and/or a salt thereof.

6. A sunscreen composition according to any preceding claim, wherein the total level of emulsifier is in the range of 4% to 5% by weight.

7. A sunscreen composition according to any preceding claim, wherein the total level of emulsifier is 4% by weight and wherein the emulsifier is one or more stearate surfactants.

8. A sunscreen composition according to any preceding claim, wherein the emulsifiers are glycerol stearate and TEA-stearate.

9. A sunscreen composition according to any preceding claim, wherein the level of film- forming polymer is from 2% to 4% by weight.

10. A sunscreen composition according to any preceding claim, wherein the film-forming polymer is a trimethylpentanediol/adipic acid/glycerin crosspolymer.

1 1 . A sunscreen composition according to any preceding claim additionally comprising a foam boosting agent at a level of from 0.5 % to 2% by weight, and wherein the foam boosting agent is a zwitterionic amphoteric surfactant.

12. A sunscreen composition according to claim 1 1 , wherein the foam boosting agent is an alkylamidobetaine

13. A sunscreen composition according to claim 12, wherein the foam boosting agent is cocamidopropylbetaine.

14. A sunscreen composition according to any preceding claim additionally comprising a propellant, wherein said propellant is present at a relative level of from 5% to 15% by weight versus the total weight of the sunscreen composition.

15. A sunscreen composition according to any preceding claim wherein the sunscreen composition is foamable.

16. A method for the preparation of an oil-in-water sunscreen formulation with water- soluble and oily UV filters comprising:

(a) Preparation of an aqueous phase comprising water soluble UV filter(s);

(b) Neutralisation of the aqueous phase to between pH 6.8 to 7.5 followed by addition of carrageenan and subsequent heating to a temperature of between 80°C to 85°C ;

(d) Emulsification of the oil phase into the aqueous gel phase followed by cooling; and