Cosmetic composition containing sucdnlc add esters.

FIELD OF THE INVENTION

The invention relates to a novel cosmetic composition for topical application to skin, hair or nails comprising a novel succinic acid derivatives having a lipid-like structure, and a coεmetically acceptable vehicle.

BACKGROUND TO THE INVENTION AND PRIOR ART

It is generally understood that ceramides present within the intercellular lipid lamellae of the stratum corneum play an important role in the production and maintenance of the water permeability barrier of the skin. Ceramides, or substances closely related to them, have been widely disclosed as components of skin care compositions.

For example Unilever NV in EP 0 097 059 disclosed the vital role played by ω-linoleoyl ceramides in the water barrier of the skin and described the synthesis and application for skin care of such ω-substituted ceramides.

Also Kao Corporation, in GB 2 178 312 and GB 2 213 723, disclose the use of natural ceramides extracted from skin in topical products, and in EP 0 227 994, they disclose synthetic analogues of ceramides.

It is believed that one of the causes of dry skin and ageing skin is a reduction in the amount of lipid contained within these intercellular lipid lamellae. It is therefore desirable to be able successfully to replace these depleted lipids via the topical route.

It has now been found that alkyl and alkenyl acid monoester alkoxylates, which are easily synthesised, also have an action analogous to that of the natural and synthetic ceramides.

SUMMARY OF THE INVENTION

Accordingly the invention provides a composition suitable for topical application. to skin, hair or nails comprising:

(i) An effective amount of at least one succinic acid derivative having the general structure (1) :

R, R. O

Rι O ( C _n H _2n O ) _χ C — CH CH C (OC H-, ) OR (1)

in which R ₁ represents an alkyl, alkenyl, mono- or dihydroxyalkyl or hydroxyalkenyl group having from 6-22 carbon atoms;

R ₂ and R ₃ individually represent H or an alkyl or alkenyl group having from 12 to 22 carbon atoms; providing that when R ₂ is H, R ₃ is an alkyl or alkenyl group and when R ₃ is H, R ₂ is an alkyl or alkenyl group;

R ₄ represents hydrogen, an alkyl, alkenyl, mono- or dihydroxyalkyl or hydroxyalkenyl group having from 6 to 22 carbon atoms or the group (2):

O R, R _? 0

II I I I! C CH CH C ( ^C _n ^H _2n °)χ ^0R ( ² )

n is an integer of from 2 to 3

x and y are average degrees of alkoxylation, namely x is from 0 to 20 and y is from 1 to 20; and

(ϋ) a cosmetically acceptable vehicle.

DISCLOSURE OF THE INVENTION

We have identified certain synthetic succinic acid derivatives which resemble in their key properties natural ceramides, these are incorporated into cosmetic compositions in an effective amount, preferably from 0.00001 to 50%, more preferably from 0.001 to 20% and most preferably from 0.1 to 10% be weight of the composition.

The succinic acid derivative

In structure (1) , the group R ₄ preferably represents H, while the group R ₁ preferably represents an alkyl group having from 16 to 22 carbon atoms and most preferably from 20 to 22 carbon atoms.

Also with reference to structure (1) , n and m are preferably 2 and (x+y) is preferably from 1 to 20.

Specific examples of these lipid components are those having the structures (3) to (7) :

O O

II II C ₁₈ H ₃₇ O C CH CH ₂ C (OC ₂ H ₄ ) ₇ . _8E0 OH

( 3 )

C ₁₅ H ₃₁ CH,

o o

II II

^C 22 ^H 45 0 — C — CH CH ₂ C ( OOfl ₇ . _8E0 OH

(4 )

C ₁₅ H ₃₁ CH,

0 O

^C 22 ^H 43 ° ^{C CH CH} 2 ^C ( ° ^C 2 ^H 4-5EO ^0H

( 5 )

C _| H _ι CH — CH

O O

C ₆ H ₁₃ — 0 C — CH CH, C ( OC ₂ H ₄ ) ₃ _ _4E0 OH

I ( 6 )

C _{1 1} H ₂₃ - CH,

0 0

^C 18 ^H 37 ° ^C CH CH, C ( 00,^ ) ^ ₀ — OH

I ( 7 ) 1 , ^H 29 CH,

The composition according to the invention may contain more than one succinic acid derivative having the structure (1) . In particular, it may be advantageous to incorporate at least two derivatives wherein for one derivative at least one of R.* and R ₂ /R ₃ is an alkenyl or hydroxyalkenyl group and for the second derivative both R*. and R ₂ /R ₃ are alkyl or hydroxyalkyl groups. A particularly preferred example of such a composition is one comprising structure (3) and structure (5) .

SYNTHESIS OF THE LIPID COMPONENT

The succinic acid derivatives of the invention are manufactured by methods of preparative chemistry that are of themselves known, starting from the known alkenylsuccinic anhydrides that can be obtained by ene- addition of maleic anhydride to olefins. Such a succinic anhydride of the general formula (8)

0 //

R CH C

\ 0 (8) R CH C

0

is reacted with an alcohol of formula R — OH to form the monoester and the monoester is then alkoxylated with (x+y) ols of ethylene oxide (n=2) or propylene oxide (n=3) , where R ¹ , R ² , R ³ , n, x and y have the meanings given for

2 3 formula 1. If it is desired that the group R or R should be an alkyl group, then the succinic anhydride of structure (8) , the monoester or the alkoxylate can be hydrogenated to saturate the double bonds that are present.

•* Suitable alcohols of the formula R OH are, for example, fatty alcohols with 6-22 carbon atoms, preferably, for example, stearyl, arachidyl, behenyl, oleyl, linoleyl and erucyl alcohol. Alkane diols and alkane triols with 6-22 carbon atoms such as, for example, ricinolyl alcohol, 9- hydroxystearyl alcohol and 9, 10-dihydroxystearyl alcohol are also suitable.

The alkoxylation of the monoester is preferably carried out in the presence of basic catalysts such as, for example, LiOH, NaOH, KOH, NaOCH ₃ , KOCH ₃ and other known catalysts for reacting ethylene oxide or propylene oxide with reactive hydroxyl groups. It is preferable to work at temperatures of 100-200°C, a slightly higher than atmospheric pressure of 1-10 bar and with an excess of ethylene or propylene oxide. The monoester of structure (1) adds a first ol of alkylene oxide to the free carboxyl group (y=l) even in the absence of a catalyst; if more than one mol of alkylene oxide is to be added, a second alkoxylation step with an alkoxylation catalyst must then follow, or alkoxylation must be carried out in the presence of a catalyst from the start.

In alkoxylation in the presence of a catalyst, alkylene oxide is also introduced into the ester bond of the monoester; this results in the attachment of the alkoxy groups designated x in structure (1) . Finally during alkoxylation there is also partial transesterification of

the alkoxylate of structure (1) with R ⁴ =H with the formation of complex esters in which R ⁴ =R ¹ 0(C _n H _2n O) _χ -CO-CHR ² -CHR ³ -CO- or has the same meaning as R . However, monoester ethoxylates of the structure (l) with R=H are the main component of the reaction mixture.

Alternatively, the monoester can also be converted into the alkali metal or alkaline earth metal salt and the latter then alkoxylated in an inert solvent.

The cosmeticallv acceptable vehicle

The composition according to the invention also comprises a cosmetically acceptable aqueous or non-aqueous vehicle to act as a dilutant, dispersant or carrier for the succinic acid derivative in the composition, so as to facilitate its distribution when the composition is applied to the skin, hair and/or nails.

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 follows:

Emollients, such as stearyl alcohol, glyceryl monoricinoleate, glyceryl onostearate, mink oil, cetyl alcohol, isoproopyl isostearate, stearic acid, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, octadecan-2-ol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, volatile or non-volatile 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, tallow, lard, olive oil, palm kernel oil, rapeseed oil, safflower seed

oil, evening primrose oil, soybean oil, sunflower seed oil, passion flower oil, avocado oil, olive oil, sesame seed oil, coconut oil, arachis oil, castor oil, acetylated lanolin alcohols, petroleum jelly, mineral oil, butyl myristate, isostearic acid, palmitatic acid, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, myristyl myristate;

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

Solvents, such as ethyl alcohol, methylene chloride, iεopropanol, acetone, squalane, εqualene, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, polyethylene glycol, dimethyl sulphoxide, dimethyl formamide, butylene glycol, tetrahydrofuran;

Powders, such as chalk, talc, fullers earth, kaolin, starch, gums, particularly xanthum gum, colloidal silica sodium polyacrylate, tetra 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 cosmetically acceptable vehicle will usually form from 10 to 99.9%, preferably from 50 to 99% by weight of the emulsion, and can, in the absence of other cosmetic adjuncts, form the balance of the composition.

OPTIONAL SKIN BENEFIT MATERIALS AND COSMETIC ADJUNCTS

Although the composition according to the invention can be aqueous or non-aqueous, a particularly convenient form is an emulsion, in which case an oil or oily material will

normally be present, together with an emulsifier to provide a water-in-oil emulsion, an oil-in-water emulsion, or a complex emulsion, depending largely on the average hydrophillic-lyophilic balance (HLB) of the emulsifier employed.

Oil or oily material

The composition according to the invention can optionally 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, such as polydimethyl siloxanes.

The oil or oily material, when present for the purposes for forming an emulsion, will normally form up to 90%, preferably from 10 to 80% by volume of the composition.

Emulsifier

The composition according to the invention can also optionally comprise one or more emulsifiers the choice of 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 HLB value of from 1 to 6. When an oil-in-water emulsion 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 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.

Table 1

Chemical Name Trade Name HLB Value of Emulsifier

Sorbitan trioleate Arlacel 85 1.8 Sorbitan tristearate Span 65 2.1 Glycerol monoleate 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) 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

400-DO 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 Polyoxyethylene (20) sorbitan tristearate Tween 65 10.5 Polyoxyethylene (20) sorbitan trioleate Tween 85 11.0

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

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-714 14.8 Polyoxyethylene (20 sorbitan monostearate Tween 14.9

Polyoxyethylene 20 sorbitan monooleate Tween 80 15.0 Polyoxyethylene (20) stearyl ether Brij 78 15.3 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 Polyoxyethylene (23) lauryl ether Brij 35 16.9 Polyoxyethylene (50) monostearatae Myrj 53 17.9 PEG 4000 monostearate Pegosperse 4000

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

Although the composition of the invention can be anhydrous, it can also comprise water, usually up to 98%, preferably from 5 to 80% by volume.

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:

where the groups R ₁₃ and R ₁₄ are each chosen from -H , C ₁₈ alkyl and - [ CH ₂ CH ₂ 0 ] _t [ CH ₂ CHO ] _u H

CH,

t has a value of from 9 to 115, u has a value of from 0 to 50, v has a value of from 133 to 673, w has a value of from 25 to 0.25.

Preferably, the dimethyl polysiloxane polymer is one in which:

t has a value of from 10 to 114 u has a value of from 0 to 49 v has a value of from 388 to 402 w has a value of from 15 to 0.75

one of groups R ₁₃ and R being lauryl, and the other having a molecular weight of from 1000 to 5000.

A particularly preferred dimethyl polysiloxane polymer is one in which:

t has the value 14 u has the value 13 v has the value 249 w 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 hexa er) .

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 0.5 to 15% by weight of the emulsion.

Other cosmetic adjuncts

Examples of conventional adjuncts which can optionally be employed include preservatives, such as para-hydroxy benzoate esters; antioxidants, such as -tocopherol, humectants, such as glycerol, sorbitol, 2-pyrrolidone-5- carboxylate, dibutylphthalate, gelatin, polyethylene, glycol, preferably PEG 200-600; buffers, such as lactic acid together with a base such as triethanolamine or sodium hydroxide; surfactants, such as glycerol ethers; waxes, such as beeswax, ozokerite wax, paraffin wax, plant

extracts, such as Aloe vera, cornflower, witch hazel, elderflower, cucumber; thickeners; activity enhancers; colourants; perfumes; and sunscreen materials such as ultrafine titanium dioxide and organic sunscreens such as p-aminobenzoic acid and esters thereof, ethylhexyl p- methoxycinnamate, 2-ethoxyethyl p-methoxycinnamate and butyl methoxydibenzoylmethane; and skin benefit agents, such as retinoic acid, retinol, retinol esters; anti- inflammatory agents, such as salicylic acid; skin whiteners, such as arbutin and mixtures thereof.

In a further preferred composition, the succinic acid derivative is combined with conventional ceramides, pseudoceramides, polyol fatty acid polyesters, sterols, particularly cholesterol, galactosyldiacyl glycerols, phospholipidε, alkyl polyglucosideε, glycosphingolipids, fatty acids and esters thereof and mixtures thereof and other ingredients well known to those skilled in the art to produce a liposomal dispersion.

A further preferred composition may also contain in combination with the succinic acid derivative and optional additional ingredients disclosed above, an organic acid component chosen from hydroxy carboxylic acids, keto carboxylic acids, esters thereof and mixtures thereof.

In yet another preferred composition, the succinic acid derivative iε diεsolved in squalene or squalane, optionally together with ceramides, and formulated with volatile and non-volatile εiliconeε to produce an anhydrous or nearly anhydrous single phaεe εyεte .

Cosmetic adjuncts can form the balance of the composition.

Use of the Composition

The composition according to the invention is intended primarily as a product for topical application to human skin, especially aε an agent for reducing the permeability of water through the εkin, particularly for treating dry, ageing or damaged εkin, in order to reduce moisture loss, increase stratum corneum flexibility and generally to enhance the quality of skin. The composition may further be used to improve skin desquamation and aε an agent to influenence epidermal differentiation. The composition can also be applied to hair and nails.

In use, a εmall quantity of the composition, for example from 0.2 to 5 ml, is applied to exposed areas of the skin, from a suitable container or applicator and, if necessary, it is then spread over and/or rubbed into the skin using the hand or fingers or a suitable device.

PRODUCT FORM AND PACKAGING

The topical skin, hair or nail treatment composition of the invention can be formulated as a lotion having a viscosity 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 viscoεity of from 20,000 to 100,000 mPaε, or above. Alternative product forms include liquids, microemulsionε, mousseε and gels.

The composition can be packaged in a suitable container to suit its viscoεity and intended uεe by the conεumer. For example, a lotion or fluid cream, or the alternative product forms 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 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.

IN VITRO MEASUREMENT OF WATER VAPOUR TRANSMISSION RATE

The reduction in water permeability of the skin following topical application of the composition according to the invention can be determined by in vitro measurement of the water vapour transmisεion rate (WVTR) uεing a water transmission cell adapted from that described by Blank I.H., J. Invest. Dermatol., [1952], 18 _. , 433-440.

Pretreatment of porcine stratum corneum

Isolated porcine stratum corneum was floated on propan-2-ol contained in a glasε petri diεh. The diεh was gently agitated for 4 hours and the sample of extracted stratum corneum was then removed, floated in saline solution onto spectra mesh and air dried overnight.

Measurement of Initial WVTR prior to treatment

850 μl distilled water was placed in the centre well of the cell and a sample of pretreated stratum corneum (see above) was carefully laid over the well ensuring that it completely covered the O-ring, εuch that a watertight εeal waε achieved. Care waε taken to avoid wrinkleε, tears and holes in the stratum corneum sample. The transmission cell was then εcrewed into poεition and allowed to equilibrate at room temperature before an initial measurement was made. The cell waε weighed after 5 minutes, then placed in an incubator at 37°C, 0% RH. Two further weight measurements were taken at suitable intervalε over a period of 24 hours at the the end of which time a test or control solution was

applied and two more measurements were taken during a further 21 hours. Five cells were used for each test or control treatment.

Study of the effect of topical application of test material

For each test, a solution of test material in chloroform/methanol (2:1 v/v) were prepared at 24 mg/ml concentration. 10 μl of this solution was applied to the previously selected propan-2-ol extracted skin as described above. The chloroform/methanol quickly evaporated. The five cells containing the skin samples were weighed after 5 minutes prior to placing in the incubator at 37°C, 0% RH. As mentioned above, two weight measurements were then taken at intervals over a period of 21 hours.

A control measurement was made using other selected skin samples. This was carried out in the same way using an equal quantity of chloroform/methanol (2:1) containing no test material.

Calculation of the WVTR

The WVTR was calculated for each sample (pre and post topical application) as follows:

weight loss

WVTR (mg/cm ² /hr) =

Area of exposed tissue x Time

The mean WVTR for each group of cells was then calculated from these values. The standard deviation was calculated from the observed changes (relative increase or decrease) in WVTR measured before and after the topical application.

Statistics

The level of significance was calculated using Duncan's Multiple Range test between WVTR measurements.

Results

The above procedure was used to asεeεs the ability of solutions of succinic acid derivatives having structures (3), (4) and (5) in admixture with cholesterol and stearic acid in a ration of 1:2:1 respectively to reduce WVTR.

These were compared with a control using chloroform/ ethanol alone. A comparison of the WVTR value before and after application of the succinic acid derivatives enables the percentage repair of the barrier function to the stratum corneum to be calculated. Results are shown in Table 1.

Table 1

EXAMPLES

The invention is illustrated by the following examples.

Example 1

This example illustrates a high internal phase water-in-oil emulsion in accordance with the invention.

A high internal phase water-in-oil emulsion having the following formulation was prepared:

% w/w

Fully hydrogenated coconut oil 3.9 Succinic acid derivative having the structure (3) 0.1

Brij 92* 5 Bentone 38 0.5

Preservative 0.3

MgSO 7H ₂ 0 0.3

Butylated hydroxy toluene 0.01

Perfume qs Water to 100

*Brij 92 is polyoxyethylene (2) oleyl ether

Example 2

This example illustrates an oil-in-water cream containing a succinic acide derivative of the invention.

An oil-in-water cream emulsion having the following formulation was prepared:

% w/w

Mineral oil 4 Succinic acid derivative having the structure (5) 0.1

Brij 56* 4 Alfol 16RD* 4

Triethanolamine 0.75

Butane-l,3-diol 3

Xanthan gum 0.3

Preservative 0.4 Perfume qs

Butylated hydroxy toluene 0.01 Water to 100

*Brij 56 is cetyl alcohol POE (10) Alfol 16RD is cetyl alcohol

Example 3

This example illustrates an alcoholic lotion containing a succinic acid derivative of the invention.

The lotion had the following formulation:

% w/w

This example illustrates an alcoholic lotion containing a succinic acid derivative of the invention.

The lotion had the following formulations:

w/w

Succinic acid derivative having the structure (7) 0.2

Dimethylsulphoxide 10

Ethanol 40

Antioxidant 0.1

Perfume qs

Water to 100

Example 5

The following composition according to the invention represents a lotion which can be used in the treatment of dry or ageing skin:

% w/w

Succinic acid derivative having the structure (3) 1.5

Perfume 0.1

Hydroxyethyl cellulose 0.4

Absolute ethanol 25 p-methyl benzoate 0.2 Sterilised demineralised water to 100

Example 6

The following composition according to the invention represents a lotion which can be used in the treatment of dry or ageing skin:

% w/w

Succinic acid derivative having the structure (5) 0.08

Ethanol 10

Perfume 0.5

Distilled water to 100

Example 7

This example illustrateε a suncare cream:

w/w

2-hydroxy-n-octanoic acid

Succinic acid derivative having the structure (4) 0.01 Silicone oil 200 cts 7.5

Glycerylmonostearate 3

Cetosteryl alcohol 1.6

Polyoxyethylene-(20) -cetyl alcohol 1.4

Xanthan gum 0.5 Parsol 1789 1.5

Octyl methoxycinnate (PARSOL MCX) 7

Perfume qs

Colour qs

Water to 100

Example 8

This example illustrates non-aqueous skincare composition:

w/w

Silicone gum SE-30 10

Silicone fluid 345 ² 20

Silicone fluid 344 ³ 55.79

Squalene 10

Succinic acid derivative having the structure (3) 0.01

Ceramides 0.01

2-hydroxy-n-octanoic acid 0.7

Vitamin A palmitate 0.5

Vitamin E linoleate 0.5

Herbal oil 0.5

Ethanol 2

A dimethyl silicone polymer having a molecular weight of at least 50,000 and a viscosity of at least 10,000 centistokes at 25°C, available from GEC

2 Dimethyl siloxane cyclic pentamer, available from Dow Corning Corp

Dimethyl siloxane tetramer, available from Dow Corning Corp

Example 9

This example illustrates a suntan lotion:

% w/w

2-keto octanoic acid 0.2

Succinic acid derivative having the structure (5) 0.02 Acetulan (cetyl acetate and acetylated lanolin alcohol) 4

Propylene glycol 3

Stearic acid 2 Dow Corning 556 fluid (phenyl dimethicone) 1 Veegum (modified magnesium aluminium silicate) 1

Cetyl alcohol 0.5

Triethanolamine 0.5 Octyl methoxycinnamate 1

Oxybenzone 1

Preservatives qs

Water to 100