CA2029263C

CA2029263C - Cosmetic composition

Info

Publication number: CA2029263C
Application number: CA002029263A
Authority: CA
Inventors: Mayara Easwaran Narayanan Nambudiry; Collur Visweswaria Natraj
Original assignee: Unilever PLC
Current assignee: Givaudan Nederland Services BV
Priority date: 1989-11-10
Filing date: 1990-11-02
Publication date: 1995-09-05
Anticipated expiration: 2010-11-02
Also published as: KR910009238A; JPH0660092B2; JPH03170416A; KR950003088B1; DE69006332T2; ES2062408T3; EP0431755A1; EP0431755B1; CA2029263A1; US5152983A; AU6591090A; ATE100705T1; MY104514A; DE69006332D1; AU628232B2; GB8925473D0; PH27155A; DK0431755T3; ZA908969B; BR9005695A

Abstract

A sunscreen composition suitable for topical application to human skin or hair, to provide protection from excessive exposure to ultra-violet rays, comprises:

i) an effective amount of a substituted 1,3-diketone having an ultra-violet absorption band within the range of from 250 to 500 nm, and an extinction coefficient ? of from 5,000 to 70,000; and ii) a physiologically acceptable vehicle for the substituted 1,3-diketone.

Description

s 2029263 - 1 - S.3017/1 SUNSCREEN COMPOSITIONS

FIELD OF THE INVENTION
lS
The invention relates to compositions comprising natural plant product isolates useful as sunscreen compounds for topical application to human skin and hair to provide enhanced protection from the damaging effects of sunlight.

BACKGROUND AND PRIOR ART

The damaging effects of sunlight on human skin have been observed since time immemorial and many remedies have been proposed to protect the skin from this damage.

In general terms, harmful ultra-violet (W) rays, particularly those originating from sunlight, which ~o penetrate the upper atmosphere and reach the earth's surface, can be classified into:

2~29263 - 2 - S.3017/1 i. the energy-rich W-B rays (290-320nm wavelength) which possess an intense physiopathological activity on the skin; these are absorbed just above the dermis and they are responsible for erythema and skin pigmentation, and ii. W-A rays (320-400nm wavelength) which penetrate deeper into the skin (to the dermis and beyond).
Their energy is much lower and the photobiological o effects they cause are much more long term in nature, for example, they accelerate skin ageing.

Certain synthetic organic substances (sunscreens) whose molecules absorb the harmful ultra-violet rays have been lS proposed for use in mitigating the deleterious effects of ultra-violet radiation. Examples include:

2-hydroxy-4-methoxy-4-methyl benzophenone also known as Benzophenone 10 (CTFA), and available from Ward Blenkinsop under the Trade Name WISTAT 2211;

2-hydroxy-4-n-octyloxybenzophenone, also known as Benzophenone 12 (CTFA), and available from American Cyanamid under the Trade Name CYASORB W 531;

2,2',4,4'-tetraheptoxybenzophenone, also known as Benzophenone 2 (CTFA), and available from BASF Chemical Co. under the Trade Name WINUL D50;

4-t-butyl-4'-methoxydibenzoylmethane, also known as Butyl Methoxy Dibenzoyl Methane (CTFA), and available from Givaudan Coporation under the Trade Name PARSOL 1789; and ~s 3 ~029263 S.3017/l 2-ethylhexyl-p-methoxy cinnamate, also known as Octyl Methoxycinnamate (CTFA), and available from Givaudan Corporation under the Trade Name PARSOL MCX.

Some of these substances absorb more effectively in W-A
range thereby providing filtering of W radiation in this range, while others are more effective in the W -B range.

A common problem exists, however, whatever the choice of synthetic organic sunscreen, for protection from whichever wavelength of ultra-violet radiation, and this is that physiological damage to the body can occur, following topical application of these sunscreens in quantities necessary to provide effective filtering of harmful ultra-violet radiation. Even those synthetic organic sunscreens that are believed to be safe to use in this way, necessarily have safety limits imposed, based on the quantity applied to the skin, which can result in only moderate to poor protection from harmful ultra-violet radiation.

Natural hydroxy anthracenic polyglycosides have been reported as sunscreens (Bader et al, Cosmetics &
Toiletries (1981), 96 (10) 67) and the use of coffee oil as a sunscreen has been reported in French Patent 2 479 688. Similarly, extracts of jujube fruits (JP 84-227813) and aloe extract (US 4,656,029) are stated to be useful in skin applications.
~o Natural extracts of aloe, frangula, senna and cascara containing anthraquinone derivatives have also been reported as useful sunscreen agents (Fox, Cosmetics &
Toiletries (1987), 102 (3), 41).
~5 2~2~263 - 4 - S.3017/1 These prior observations suggesting the use of natural materials as sunscreen agents have generated only limited commercial use, and none is as effective as most of the aforementioned synthetic sunscreens.
s We have now discovered a series of substituted 1,3-diketones, which can be isolated from natural sources, which have wide spectrum absorption properties spanning both the W-A & W-B ranges, and which can be employed as sunscreen agents in cosmetic compositions particularly suited for topical application to the skin or hair. These naturally occurring substituted 1,3-diketones can accordingly be used in place of synthetic W-A ~ W -B
screening compounds in skin compositions, such as those, lS particuarly PARSOL 1789, referred to hereinbefore.

DEFINITION OF THE INVENTION

Accordingly, the invention provides a composition suitable for topical application to human skin or hair to provide protection from excessive exposure to ultra-violet rays, which comprises an effective amount of a substituted 1,3-diketone, having an ultra-violet absorption band in 2S the range of from 250 to 500 nm, and an extinction coefficient ~ of from 5,000 to 70,000, together with a physiologically acceptable vehicle for the substituted 1,3-diketone.

3 o DISCLOSURE OF THE INVENTION

The substituted 1,3-diketone The composition according to the invention comprises as a sunscreen a substituted 1,3-diketone in an amount sufficient to provide protection from excessive exposure to ultra-violet rays.

r,t ~. ' 202~263 - 5 - S.3017/1 The substituted 1,3-diketone will normally have an absorption band in the region of from 250 to 500 nm, spanning both the W -A and W -B ranges, and an extinction coefficient ~ of from 5,000 to 70,000.
s Preferably, the sunscreen has a basic 1,3-diketone chromophore and suitable auxochrome groups providing at least one absorption band in the 280-450 nm region and an extinction coeffcient ~ of from 10,000 to 60,000.

A preferred group of sunscreens for use in the composition according to the invention are shown by tautomeric structures (1) and (2):

1/\/\ R2 (1) H

O O

2 5 Rl/~J\\ R2 ( 2) wherein R1 and R2 may be the same or different, and are chosen from benzylidine, substituted benzylidine, phenyl or substituted phenyl groups.

Preferred examples of the groups R1 and R2 are shown in 3S the following structures (3) to (7):

202~2`6~
-- 6 - S. 3017/1 113Co~~

s Ho ~y ~o/bJ ~4 ~/ (5) 2s <~/ (6) ~ O

~_ _ 7 _ 2029263 S.3017/1 Specific examples of natural compounds for use in the composition of the invention are curcumin, and its analogues demethoxy and didemethoxy curcumin, which can be isolated from Curcuma longa roots, and pongamol which can be isolated from Pongamia glabra seeds.

Curcumin is also known as di-4-hydroxy-3-methoxycinnamoyl lS methane and has the structure (8):

O O

~5 ~~ ~

`~ ~52~263 - 8 - S.3017/1 Pongamol is also known as 1,3-propanedione, 1-(4-methoxy--5-benzofuranyl)-3-phenyl and has the structure (9):

O C

OC~3 The compounds used in the compositions of the invention lS are effective as sunscreen agents either as pure compounds, as a concentrate of an appropriate natural isolate which comprises the substituted 1,3-diketone compound, or as a crude extract of the natural source material or even as the natural source material itself.
~ ,Y~o_~Jo_ 20 ~ For example, k~anji oil can be used in this manner as a source of pongamol.

The composition according to the invention preferably comprises from 0.01 to 15% by weight of the substituted 1,3-diketone.

The Physiologically Acceptable Vehicle The composition according to the invention also comprises a physiologically and cosmetically acceptable vehicle to act as a dilutant, dispersant or carrier for other materials present in the composition, so as to facilitate their distribution when the composition is applied to the ~5 skin and/or hair.

~ 202~263 - 9 - S.3017/1 Vehicles other than water can include liquid or solid emollients, solvents, humectants, thickeners and powders.
Examples of each of these types of vehicle, which can be used singly or as mixtures of one or more vehicles, are as s follows Emollients, such as stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, stearic acid, isobutyl palmitate, isocetyl o stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, octadecan-2-ol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, silicone oils such as dimethylpolysiloxane, di-n-butyl sebacate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, butyl stearate, polyethylene glycol, triethylene glycol, lanolin, cocoa butter, corn oil, cotton seed oil, olive oil, palm kernel oil, rapeseed oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame seed oil, coconut oil, arachis oil, castor oil, acetylated lanolin alcohols, petroleum jelly, mineral oil, butyl myristate, isostearic acid, palmitic acid, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, myristyl myristate;

Propellants, such as propane, butane, isobutane, dimethyl ether, carbon dioxide, nitrous oxide;

Solvents, such as ethyl alcohol, methylene chloride, isopropanol, acetone, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, dimethyl sulphoxide, dimethyl formamide, tetrahydrofuran;

~5 Powders, such as chalk, talc, fullers earth, kaolin, starch, gums, colloidal silica sodium polyacrylate, tetra 202~263 - 10 - S.3017/1 alkyl and/or trialkyl aryl ammonium smectites, chemically modified magnesium aluminium silicate, organically modified montmorillonite clay, hydrated aluminium silicate, fumed silica, carboxyvinyl polymer, sodium carboxymethyl cellulose, ethylene glycol monostearate.

The physiologically acceptable vehicle will usually form from 10 to 99.9%, preferably from 50 to 99~ by weight of the composition, and can, in the absence of other cosmetic o adjuncts, form the balance of the emulsion.

OPTIONAL SKIN BENEFIT MATERIALS AND COSMETIC ADJUNCTS

A particularly convenient form of the composition according to the invention is an emulsion, in which case an oil or oily material will normally be present, together with an emulsifier to provide either a water-in-oil emulsion or an oil-in-water emulsion, depending largely on the average hydrophilic-lyophilic balance (HLB) of the emulsifier employed.

Oil or oily material The composition according to the invention can optionally 2s comprise one or more oils or other materials having the properties of an oil.

Examples of suitable oils include mineral oil and vegetable oils, and oil materials, such as those already proposed herein as emollients. Other oils or oily materials include silicone oils, both volatile and non-volatile.

~s Suitable non-volatile silicones include polyalkyl siloxanes, polyalkylaryl siloxanes or mixtures thereof.

- 11 - S.3017/1 Examples of polyalkyl siloxanes include polydimethyl siloxanes having a viscosity of from 5 to 100,000 centistokes at 25C. These siloxanes are available commercially from the General Electric Company as the Viscasil series and from Dow Corning as 244, 245, 344, 345, 200/5 and 200 fluids. Other examples include Silicones 7202 and 7518 from Union Carbide and SWS 03314 from Stauffer Chemical.

The viscosity can be measured by means of a glass capillary viscometer as set forth in Dow Corning Corporate Test Method CTM004 July 20, 1970.

Also suitable is polydiethyl siloxane.

Examples of polyalkylaryl siloxanes include polymethylphenyl polysiloxanes having a viscosity of from 15 to 65 centistokes at 25C. These siloxanes are available commercially from the General Electric Company as SF 1075 methyl phenyl fluid or from Dow Corning as 556 Cosmetic Grade Fluid.

Suitable volatile silicones are cyclic or linear polydimethyl siloxanes. The number of silicone atoms in the cyclic silicones is 3 to 7, most preferably 4 or 5.
The general formula for cyclic silicones is:

tsi ~ ]n I

wherein n is an integer of from 3 to 7. Viscosities are generally less than 10 centipoise (cP) at 25C.

- 12 - S.3017/1 Linear polydimethyl siloxanes are those having a viscosity of less than 5cP at 25C. The linear volatile silicones usually contain from 3 to 9 silicon atoms and have the general formula:
s (CH3)3 Si--tsi (CH3)2o]mSi (CH3)3 wherein m is an integer of from 1 to 7.

Silicones of the above described types are widely available and examples include those available from Dow Corning such as 244, 245, 344, 345, 200/5 and 200 Fluids from Union Carbide such as Silicone 7202 and 7158, and from Stauffer Chemical such as SWS-03314.
lS
The oil or oily material, when present for the purposes for forming an emulsion, will normally form up to go~, preferably from lo to 80% by volume of the composition.

It is to be understood that the oil or oily material when present can also possess emollient properties and can accordingly also function as a physiological acceptable vehicle as hereinbefore defined.

Emulsifier The composition according to the invention can also optionally comprise one or more emulsifiers the choice of o which will normally determine whether a water-in-oil or and oil-in-water emulsion is formed.

When a water-in-oil emulsion is required, the chosen emulsifier or emulsifiers should normally have an average ~5 HLB value of from 1 to 6. When an oil-in-water emulsion ~ 2029263 - 13 - S.3017/1 is required, a chosen emulsifier or emulsifiers should have an average HLB value of >6.

Examples of suitable emulsifiers are set below in Table 1 s in which the chemical name of the emulsifiers is given together with an example of a trade name as commercially available, and the average HLB value.

2Q2~263 - 14 - S.3017/1 Table 1 __________________________________________________________ Chemical Name Trade Name HLB Value of Emulsifier s _ ______________ Sorbitan trioleate Arlacel 85 1.8 Sorbitan tristearate Span 65 2.1 Glycerol monooleate Aldo MD 2.7 Glycerol monostearate Atmul 84S 2.8 Glycerol monolaurate Aldo MC 3.3 Sorbitan sesquioleate Arlacel 83 3.7 Sorbitan monooleate Arlacel 80 4.3 Sorbitan monostearate Arlacel 60 4.7 Poloxyethylene (2) lS stearyl ether Brij 72 4.9 Poloxyethylene sorbitol beeswax derivative G-1702 5 PEG 200 dilaurate Emerest 2622 6.3 Sorbitan monopalmitate Arlacel 40 6.7 Polyoxyethylene (3.5) nonyl phenol Emulgen 903 7.8 PEG 200 monostearate Tegester PEG
200 MS 8.5 Sorbitan monolaurate Arlacel 200 8.6 PEG 400 dioleate Tegester PEG
400-D0 8.8 Polyoxyethylene (5) monostearate Ethofat 60-16 9.0 Polyoxyethylene (4) sorbitan monostearate Tween 61 9.6 Polyoxyethylene (4) lauryl ether Brij 30 9.7 Polyoxyethylene (5) sorbitan monooleate Tween 81 10.0 PEG 300 monooleate Neutronyx 834 10.4 202~263 - 15 - S.3017/1 Polyoxyethylene (20) sorbitan tristearate Tween 65 10.5 Polyoxyethylene (20) sorbitan trioleate Tween 85 11.0 s Polyoxyethylene (8) monostearate Myrj 45 11.1 PEG 400 monooleate Emerest 2646 11.7 PEG 400 monostearate Tegester PEG 400 11.9 Polyoxyethylene 10 monooleate Ethofat 0/20 12.2 Polyoxyethylene (10) stearyl ether Brij 76 12.4 Polyoxyethylene (10) cetyl ether Brij 56 12.9 S Polyoxyethylene (9.3) octyl phenol Triton X-100 13.0 Polyoxyethylene (4) sorbitan monolaurate Tween 21 13.3 PEG 600 monooleate Emerest 2660 13.7 PEG 1000 dilaurate Kessco 13.9 Polyoxyethylene sorbitol lanolin derivative G-1441 14.0 Polyoxyethylene (12) lauryl ether Ethosperse LA-12 14.4 PEG 1500 dioleate Pegosperse 1500 14.6 Polyoxyethylene (14) laurate Arosurf HFL-71414.8 Polyoxyethylene (20) sorbitan monostearate Tween 14.9 Polyoxyethylene 20 sorbitan monooleate Tween 80 15.0 Polyoxyethylene (20) stearyl ether Brij 78 15.3 -'_ - 16 - S.3017/1 Polyoxyethylene (20) sorbitan monopalmitate Tween 40 15.6 Polyoxyethylene (20) cetyl ether Brij 58 15.7 Polyoxyethylene (25) oxypropylene G-2162 16.0 monostearate Polyoxyethylene (20) sorbitol monolaurate Tween 20 16.7 lo Polyoxyethylene (23) lauryl ether Brij 35 16.9 Polyoxyethylene (50) monostearate Myrj 53 17.9 PEG 4000 monostearate Pegosperse 4000 lS MS 18.7 ____________________________________ ________________ The foregoing list of emulsifiers is not intended to be limiting and merely exemplifies selected emulsifiers which are suitable for use in accordance with the invention.

It is to be understood that two or more emulsifiers can be employed if desired.

The amount of emulsifier or mixtures thereof, to be incorporated in the composition of the invention, when appropriate is from 1 to 50%, preferably from 2 to 20% and most preferably from 2 to 10% by weight of the composition.

Water The composition of the invention can also comprise water, usually up to 80%, preferably from 5 to 80% by volume.
~s - 17 - S.3017/1 Silicone Surfactant The composition of the invention can also optionally comprise a high molecular weight silicone surfactant which can also act as an emulsifier, in place of or in addition to the optional emulsifier(s) already mentioned.

The silicone surfactant is a high molecular weight polymer of dimethyl polysiloxane with polyoxyethylene and/or polyoxypropylene side chains having a molecular weight of from 10,000 to 50,000 and having the structure:

CH3-Si o Si - O - Si 0 - Si CH3 CH3 R1 R ~ CH3 x Y

where the groups R' and R" are each chosen from -H, Cl_18 alkyl and ~ [cH2cH2o]a~cH2cHo]bH
I

2s a has a value of from 9 to 115, b has a value of from 0 to 50, x has a value of from 133 to 673, y has a value of from 25 to 0.25.

Preferably, the dimethyl polysiloxane polymer is one in which:

~5 a has a value of from 10 to 114 b has a value of from 0 to 49 - 18 - S.3017/1 x has a value of from 388 to 402 y has a value of from 15 to 0.75 one of groups R' and R" being lauryl, and the other having a molcular weight of from 1000 to 5000-A particularly preferred dimethyl polysiloxane polymer is one in which:

a has the value 14 b has the value 13 x has the value 249 y has the value 1.25 The dimethyl polysiloxane polymer is conveniently provided as a dispersion in a volatile siloxane, the dispersion comprising, for example, from 1 to 20% by volume of the polymer and from 80 to 99% by volume of the volatile siloxane. Ideally, the dispersion consists of a 10% by volume of the polymer dispersed in the volatile siloxane.

Examples of the volatile siloxanes in which the polysiloxane polymer can be dispersed include polydimethyl siloxane (pentamer and/or hexamer).

A particularly preferred silicone surfactant is cyclomethicone and dimethicone copolyol, such as DC 3225C
Formulation Aid available from DOW CORNING. Another is laurylmethicone copolyol, such as DC Q2-5200, also available from Dow Corning.

The amount of silicone surfactant, when present in the composition will normally be up to 25%, preferably from ~s 0.5 to 15% by weight of the emulsion.

- 19 - S.3017/1 Optional Orqanic sunscreens The composition of the invention optionally can comprise a synthetic organic sunscreen, in addition to the substituted 1,3-diketone obtainable from natural plant sources, as hereinbefore defined, further to enhance the benefit of the composition in providing protection from the harmful effects of excessive exposure to sunlight.

~o As has already been stated, some synthetic organic sunscreens can be harmful to health if applied topically to the skin at a concentration sufficient to screen out effectively radiation from either the W -A range or the W -B range. The presence however, of a naturally-occurring substituted 1,3-diketone, which can - ~rovide broad spectrum protection both the W5~A~a~ndt ~ -B
A ranges, enables a lower than usual amount of~ organic sunscreen materials to be used to "top-up" the overall Sun Protection Factor of the composition to an exceptionally high level, without the risk of causing the type of skin damage or other health problems that can be associated with the use of higher levels of synthetic organic sunscreen materials alone.

In view of this, a relatively small amount of synthetic organic sunscreen optionally can be incorporated into the composition of the invention.

3 0 Examples of suitable synthetic organic sunscreens, when required, include those set out in Table 2 below, and mixtures thereof.

~s 20 29 2~3 - 20 - S.3017/1 CTFA Name Trade Name Supplier ______________________ _________ ________ Benzophenone-l UVlNU~ 400 BASF Chemical Co.
Benzophenone-2 UVlNU~ D-50 BASF Chemical Co.
Benzophenone-3 UVlNUJ M-40 BASF Chemical Co.
Benzophenone-4 UVl~U~ MS-40 BASF Chemical Co.
Benzophenone-6 WINUL D-49 BASF Chemical Co.
Benzophenone-8 SPECRA-SORB W-24 American Cyanamide Benzophenone-10 WISTAT 2211 Ward Blenkinsop Benzophenone-12 CYASORB W531 American Cyanamide DEA
Methoxycinnamate BERNEL HYDRO Bernel Chemical Ethyl dihydroxy-propyl-PABA AMERSCREEN P Amerchol Corp.
Glyceryl PABA NIPA G.M.P.A. Nipa Labs.
Homosalate KEMESTER HMS Hunko Chemical Methyl anthranilate SUNAROME WA Felton Worldwide Octocrylene WINUL N-539 BASF Chemical Co.
Octyl dimethyl PABA AMERSCOL Amerchol Corp.
Octyl methoxy-cinnamate PARSOL MCX Givaudin Corpn.
Octyl salicylate SUNAROME WMO Felton Worldwide PABA PABA National Starch 2-Phenyl-3 o benzimidazole--5-sulphonic acid EUSOLEX 232 EM Industries TEA salicylate SUNAROME W Felton Worldwide 3-(4-methylbenzy-lidene)-camphor EUSOLEX 6300 EM Industries ~s _ 2029263 - 21 - S.3017/1 4-Isopropyl dibenzoyl methane EUSOLEX 8020 EM Industries Butyl methoxy di-benzoyl methane PARSOL 1789 Givaudan Corp.
sEtocryiene WINUL N-35 BASF Chemical Co.

The composition of the invention can accordingly h optionally comprise f~o~,0 1 to 10%, preferably from 1 to 5% by weight of ~n~organic sunscreen material.

Optional Inorganic Sunscreens The composition of the invention optionally can also comprise an inorganic sunscreen.

Examples of inorganic sunscreens include:

titanium dioxide, having an average particle size of <100 nm (also known as ultrafine titanium dioxide), zinc oxide, having an average particle size of from 1 to 300nm, 2S iron oxide, having an average particle size of from 1 to 300nm, silica, such as fumed silica, having an average particle size of from 1 to 100nm.

It should be noted that silica, when used as an ingredient in the composition according to the invention can provide protection from infra-red radiation.

- 22 - S.3017/1 Other Cosmetic Adjuncts Examples of conventional adjuncts which can optionally be employed include preservatives, such as para-hydroxy benzoate esters; antioxidants, such butyl hydroxy toluene;
humectants, such as glycerol, sorbitol, 2-pyrrolidone-5-carboxylate, dibutylphthalate, gelatin, polyethylene glycol, such as PEG 200-600; buffers, such as lactic acid together with a base such as triethanolamine or sodium hydroxide; waxes, such as beeswax, ozokerite wax, paraffin wax; plant extracts, in addition those containing a substituted 1,3-diketone, that can be derived from plant sources such as Aloe vera, cornflower, witch hazel, elderflower, cucumber; thickeners; activity enhancers; colourants; and perfumes. Cosmetic adjuncts can form the balance of the composition.

Use of the Com~osition The composition according to the invention is intended primarily as a sun care product for topical application to human skin or hair, to provide protection from the harmful effects of excessive exposure to sunlight.
2s In use, a small quantity of the composition, for example from 1 to Sml, is applied to exposed areas of the skin or hair, from a suitable container or applicator and, if necessary, it is then spread over and/or rubbed into the 3 O skin or hair using the hand or fingers or a suitable device.

PRODUCT FORM AND PACKAGING

~s The topical skin and/or hair treatment composition of the invention can be formulated as a lotion having a viscosity -2~292~3 - 23 - S.3017/1 of from 4,000 to 10,000 mPas, a fluid cream having a viscosity of from 10,000 to 20,000 mPas or a cream having a viscosity of from 20,000 to 100,000 mPas, or above. The composition can be packaged in a suitable container to suit its viscosity and intended use by the consumer.
For example, a lotion or fiuid cream can be packaged in a bottle or a roll-ball applicator or a propellant-driven aerosol device or a container fitted with a pump suitable for finger operation. When the composition is a cream, it o can simply be stored in a non-deformable bottle or squeeze container, such as a tube or a lidded jar.

The invention accordingly also provides a closed container containing a cosmetically acceptable composition as herein defined.

Method for determination of Sun Protection Factor (SPF~
in vitro The method for the in vitro SPF determination of the composition of the invention involves the spectrophotometric scanning of stratum corneum between 400nm and 290nm utilising a Perkin Elmer Lamba 17 spectrophotometer equipped with a diffuse transmission detection system.

Guinea pig stratum corneum is used in place of human skin and the following procedure is followed.
~o i. Guinea pig stratum corneum is isolated as fine sheets from guinea pig skin and air dried.

ii. A piece of the stratum corneum is applied to the outer surface of a 0.5 cm quartz cuvette using a drop - 24 - S.3017/1 of distilled water to seal the stratum corneum uniformly to the quartz surface.

iii. The quartz cuvette carrying the piece of stratum s corneum is placed in the light path of the spectrophotometer which for this purpose is fitted with a fluorescence cut-off filter. This filter eliminates the autofluorescence of the stratum corneum and filters out all transmissions above o 400nm.

iv. The stratum corneum is scanned from 290 to 400nm and the spectrum obtained is saved as the control.

v. The cuvette with stratum corneum is removed from the spectrophotometer and the test material (i.e.
sunscreen) is applied to the stratum corneum at the rate of 1.5 ~l/cm2, in accordance with German DIN
protocol, and rubbed uniformly across the entire surface of the skin using the finger fitted with a finger stall.

vi. The applied sunscreen material is allowed to stand for 5 minutes at room temperature (20C) to enable it to dry, and then the sample is rescanned in the spectrophotometer as before from 290 to 400nm. This spectrum is saved as the test spectrum. No spectral absorbance changes were observed with drying times 3 0 between 2 and 15 minutes; the 5 minute drying time was therefore adopted as standard.

vii. The control spectrum is subtracted from the test spectrum to provide the spectral absorbance of the ~s test sample of sunscreen material and this absorbence is converted to transmission.

._ - 25 - S.3017/1 viii.The in vitro Sun Protection Factor (SPF) is finally calculated from the transmission measurements as described by Diffey et al, in a paper entitled: "A
new substrate to measure sunscreen protection factors throughout the ultra-violet spectrum" in J. Soc.
Cosmet. Chem. 40, 127-133 (May/June lg89); see especially page 130.

EXPERIMENT

The following experiment confirms the effectiveness as sunscreen agents of 2 naturally occurring substituted 1,3-diketones, as compared with 2 commercially available synthetic sunscreen agents.

lS
In this experiment, albino guinea pigs are depilated on their backs. 24 hours later, a resin template containing three 2 cm x 2 cm apertures was strapped on the backs of the animals and the apertures marked. A solution of pongamol or curcumin at concentrations ranging from 0.25 to 2 mg/sq.cm. in alcohol was applied on the marked areas.
A neighbouring patch was identically treated with alcohol alone. 15 minutes after application of the product, the template was strapped back on and the animal was irradiated by a Wotan Ultravitalux W lamp (300 W) from a distance of 15 cm for 6 mins. The template was removed and the erythema was scored 4 hours afte irradiation and graded on a 5 point scale. For comparison, standard synthetic sunscreen agents, Parsol MCX and 1789 ex Givaudan were used. Curcumin and pongamol used in these studies were of natural origin and obtained from turmeric roots and karanja seed respectively.

- 26 - S.3017/1 Compound Eythema Blank 2.5-3.5 Parsol MCX (0.3 mg/sq.cm) 1.5-2.5 s Parsol 1789 (0.5 mg/sq.cm) 1.0-1.5 Curcumin (2.0 mg/sq.cm) 0.0-1.0 Pangamol (0.7 mg/sq.cm) 0.5-1.0 Pongamol (0.8 mg/sq.cm) 0.0-1.5 It was concluded that both Curcumin and Pongamol were effective in terms of protection from erythema in guinea pigs.

EXAMPLES

The invention is further illustrated with reference to the following examples.

Example 1 This example illustrates a composition according to the invention comprising Pongamol as the natural substituted 1,3-diketone sunscreen agent. Results are also given 2S showing the effectiveness of this composition using a panel of human volunteers.

Pongamol was incorporated at 1.2% by weight and 0.6% by weight in a vanishing cream base containing 18% by weight stearic acid, 0.5% by weight potassium hydroxide, 1.0% by ~ weight glycerine, 0.2% by weight pre ~ vative. A control A cream did not contain pongamol. A ~sin template containing three 1 cm x 1 cm apertures was strapped onto the arms of human voluneers and the apertures marked out.
The cream (5 mg/sq cm) was applied to the areas marked.
15 minutes later, the template was strapped back and - 27 - S.3017/1 irradiated for up to 6 minutes (depending on the skin colour of the volunteers) with a Wotan Ultravitalux W
lamp t300 W) from a distance of 15 cm. The template was removed and the tanning evaluated visually daily for 10 s days. The results of evaluation at the end of 5 days are shown in Table 3 below:

o Panellist Conditions Results (decreasing (duration of sunscreen efficacy, irradiation) increasing tanning 1 5 minutes Left arm 1.2% ~ 0.6% > Control Right arm 1.2% > 0.6% > Control 2 5 minutes ~eft arm 1.2% > 0.6% > Control 3 5~ minutes Left arm 1.2% > 0.6% ~ Control 4 5 minutes Right arm 1.2~ > 0.6% > Control It was found that creams containing pongamol afforded protection from tanning in this experiment.

ExamDle 2 2s This example illustrates the use of a natural substituted 1,3-diketone when incorporated together with a synthetic sunscreen in a vanishing cream base composition.

Pongamol was incorporated along with a known UV B
sunscreen (Parsol MCX ex. Givaudan) in a vanishing cream base containing by weight 18% stearic acid, 0.5% potassium hydroxide, 1% glycerine, 0.2% preservative. The levels of Parsol MCX and Pongamol were 1.0 and 0.7; 1.5 and 0.4;
A 2.0 and 0.3; 2.5 and 0.3%. Creams containing Parsol MCX
C~
and Parsol 1789 (ex-Givaudan) in a vanishing base _ 202926~
- 28 - S.3017/1 containing 18% stearic acid, 0.5% potassium hydroxide, 1.0% glycerine, 0.2% preservative were formulated. The levels of Parsol MCX and Parsol 1789 were 1.0 and 0.2;
1.0 and 0.5; 1.25 and 0.4; 2.5 and 0.2% respectively.
s The forearm of each of a panel of volunteers was washed with soap and water and patted dry. A rexin template containing five 1 cm x 1 cm apertures was strapped onto the forearms of volunteers and the apertures marked out.
o The reflectance from the skin in the marked areas was determined using an instrument which quantified the reflectance from a circular patch of skin 1 cm in diameter. The various creams were applied (4 mg) onto the marked area. Fifteen minutes later, the template was lS strapped back on and the arms irradiated with a Wotan Ultravitalux W lamp (300 W) from a distance of 15 cm.
The templates were removed and the tanning evaluated visually (subjective score) on a 0 to 8 point scale and by measuring the reflectance. The results at the end of 5 days is given in the Table 4 below. All values are means of several independent determinations (numbers in parenthesis).

~0 - 29 - S.3017/1 Parsol MCX: Parsol MCX: Visua~ Reflectance A Parsol 1789 -~an~am4~ ~onga~o~ R) ~ _____________ _______________________________ Placebo 3.30 + 0.17(14) -208 + 10 (10) 1 : 0.2 1.35 + 0.19(14) -119 + 9 (10) 1.25 : 0.4 0.93 + 0.14(14) - 75 + 12 (10) 2.5 : 0.2 0.68 + 0.13(14) - 69 + 14 (10) o 1.0 : 0.7 1.21 + 0.2 (7)- 23 + 13 (5) 1.5 : 0.4 0.77 + 0.19 (6) - 30 + 31 (6) 2.0 : 0.3 0.83 + 0.11 (6) - 36 + 26 (6) 2.5 : 0.3 0.68 + 0.15 (7) - 14 + 13 (5) __________________________________________________________ lS From the above, it was concluded that Pongamol protects the skin from the effects of W radiation in a manner analogous to a well-known W-A sunscreen - Parsol 1789.

~5 202926~
- 30 - S.3017/1 Example 3 This example illustrates a lotion according to the invention.

Ingredient ~ w/w silicone surfactant 10.0 o volatile siloxane 14.0 mineral oil 1.5 Pongamol 1.5 titanium dioxide (water-dispersible) 2.5 titanium dioxide (oil-dispersible) 2.5 2-hydroxy octanoic acid 1.0 2-hydroxy propanoic acid 5.0 butylene glycol 10.0 sodium chloride 2.0 l-proline 0.1 neutralising agent qs preservative qs perfume qs water qs ~o 202~26~
-- 31 - S.3017/1 Example 4 This example illustrates a fluid cream according to the invention.
s Ingredient % w/w volatile siloxane (DC 345) 8.2 silicone surfactant (DC 3225C) 12.0 petroleum jelly 0.5 mineral oil 1.5 Pongamol 2.0 Parsol MCX (octyl methoxycinnamate) 3.0 titanium dioxide (oil-dispersible) 2.0 S titanium dioxide (water-dispersible) 2.0 sodium chloride 2.0 butylene glycol 10.0 l-proline 0.1 2-hydroxy octanoic acid 1.0 2-hydroxy propanoic acid 5.0 neutralising agent qs preservative qs perfume qs water qs 202~263 - 32 - S.3017/1 Example S

This example illustrates a cream according to the invention.
s Ingredient % w/w volatile siloxane (DC 345 Fluid) 8.2 silicone surfactant (DC 3225C) 12.0 o mineral oil 1.5 Curcumin 0.5 petroleum jelly 0.5 Parsol MCX (octyl methoxycinnamate) 1.5 titanium dioxide (oil-dispersible) 1.0 S titanium dioxide (water-dispersible) 1.0 2-hydroxyoctanoic acid 1.0 2-hydroxypropanoic acid 5.0 sodium chloride 2.0 butylene glycol 10.0 l-proline 0.1 neutralising agent (aqueous phase to 4.5) q.s preservative q.s perfume q.s water to 100 ~o - 33 - S.3017/1 Exam~le 6 This example illustrates a lotion according to the invention.
s Ingredient % w/w silicone surfactant (DC 3225C) 10.0 volatile siloxane (DC 345) 14.0 ~o mineral oil 1.5 Pongamol 0-5 Curcumin 0-5 Parsol MCX 3.0 titanium dioxide (oil-dispersible) 2.0 S titanium dioxide (water-dispersible) 2.0 butylene glycol 10.0 sodium chloride 2.0 l-proline o.
2-hydroxy octanoic acid 1.0 2-hydroxy propanoic acid 5.0 neutralising agent qs perfume qs preservative qs 2 S water qs

Claims

1. A sunscreen composition suitable for topical application to human skin or hair to provide protection from excessive exposure to ultra-violet rays, which comprises:

i) an effective amount of a substituted 1,3-diketone having an ultra-violet absorption band within the range of from 250 to 500 nm, and an extinction coeficient .SIGMA. of from 5,000 to 70,000; and ii) a physiologically acceptable vehicle for the substituted 1,3-diketone, and in which the 1,3-diketone has the structure (1):

(1) or its tautomer having the structure (2):

(2) where R1 and R2 are the same or different, and in which the groups R1 and R2 are chosen from (3) (6) (7)

2. A composition according to claim 1, in which the substituted diketone is di-4-hydroxy-3-methoxycinnamoylmethane (curcumin) having the structure (8):

(8)

3. A composition according to claim 1, in which the substituted 1,3-diketone is 1,3-propanedione, 1-(4-methoxy-5-benzofuranyl)-3-phenyl (Pongamol) having the structure (9):

(9)

4. A composition according to claims 1, 2 or 3, in which the 1,3-diketone forms from 0.01 to 15% by weight of the composition.

5. A composition according to claim 1, 2 or 3, which in the form of a cream or lotion.