FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2006
PROVISIONAL SPECIFICATION
(See Section 10 and Rule 13)
ULTRAVIOLET LIGHT ABSORBING SILICONE COMPOUNDS, PROCESS FOR MAKING SAME AND COSMETIC COMPOSITIONS THEREFROM
HINDUSTAN LEVER LIMITED, a company incorporated under the Indian Companies Act, 1913 and having its registered office at Hindustan Lever House, 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India
The following specification describes the invention

- 1 -
5 FIELD OF INVENTION
The present invention relates to ultraviolet light absorbing si1icone compounds.
10 The invention has been developed primarily for use in personal
care compositions and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.
15 BACKGROUND OF THE INVENTION
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in
20 the field.
Solar radiation includes about 5% Ultraviolet (UV) radiation, wavelength of which is between 200nm and 400nm. It is further classified into three regions; from 320 to 400 nm, 290 to 320 nm
25 and from 200 to 290nm. These are respectively designated as UV-A, UV-B and UV-C regions. A large part of UV-C radiation is absorbed by the Ozone layer.
Scientific studies have indicated that exposure to UV-A and UV-B 30 radiation for short period causes reddening of the skin and
localized irritation, whereas continued and prolonged exposure can lead to sunburn, melanoma and formation of wrinkles. It is also reported that UV radiation causes significant damage to hair. Therefore, it is desirable to protect the skin from the harmful
35 effects of both, UV-A and UV-B radiation.
Personal care products such as creams and lotions are used to mitigate these effects and/or to prevent further damage. For this

- 2 -
5 purpose, sunscreens or sun block agents are generally added
therein to protect the skin from harmful effects of UV radiation.
Organic sunscreens absorb a large fraction of the incident UV radiation, thereby preventing the radiation from coming in contact
10 with the surface of the skin. They have UV absorbing sites, called chromophores, which are primarily responsible for their activity.
Some sunscreens absorb UV-A radiation while some absorb UV-B radiation.
15 It is known that some organic sunscreens and their photo-degradation residues are capable of penetrating through the layers of the skin. These residues are known to cause localized irritation, allergic reactions and sensitized skin and tissues. On the other hand, once applied to the skin in the form of a cosmetic
20 composition, sunscreens are generally expected to remain thereon and continue to remain effective for an appreciable amount of time. This demand becomes difficult to meet when the body comes in contact with water e.g. while swimming or on perspiration, after application of the cosmetic composition. Therefore, in addition to
25 being efficacious, sunscreens are also expected to be substantive, safe and easy to incorporate in various types of formulations.
To this end, some attempts have been made, which meet some of the above requirements.
30
Silicone elastomers such as DC9040™, which is a commercially marketed product by Dow Corning, are included in cosmetics along with sunscreens to increase their substantivity on the skin. On the other hand, some attempts have also been made to combine
35 silicones and organic sunscreens by way of covalent bonding to reduce trans-dermal penetration of sunscreens and/or increase their substantivity.

- 3 -
5 US 4,868, 251 (1989, Allergen INC) describes UV radiation
absorbing silicone compositions which are made by reacting a terminal vinyl functional base silicone polymer with a silicone
crosslinker having plurality of hydride functional groups, in the presence of a terminal vinyl functional UV absorbing moiety.
10 During the reaction, the crosslinker reacts simultaneously with
the base polymer and the UV absorbing moiety, leading to a highly crosslinked gelled material, which is used for making contact lenses. Due to the highly crosslinked nature, this material is unsuitable for use in cosmetics.
15
WO 03 027168 (Silver, Michael, E.) describes high molecular weight silicone elastomers having covalently bound UV absorbing organic sunscreen. These are made by reacting reactive silicone base polymer with reactive UV absorbing sunscreens. These elastomers
2 0 are said to address the issues pertaining to formulation
complexity and toxicity. However, the silicone base polymers used herein do bond with themselves, thereby leading to a highly crosslinked material which, is relatively difficult to incorporate in cosmetic compositions.
25
In our co-pending application 514/MUM/2006 we have described a method for stabilization of UV-A sunscreens by covalently binding them to a linear polymeric silicone backbone along with UV-B sunscreens. These compounds are used in cosmetic compositions to
30 provide protection against UV-A and UV-B radiations. The compounds synthesized according to this co-pending application have been found to be relatively difficult to incorporate in cosmetic compositions.
3 5 The present inventors have found out an improved way of doing so,
which overcomes some of the limitations of this co-pending application.

- 4 -
5 Thus there exists the need for silicone based ultraviolet light absorbing compounds which are relatively easy to incorporate in cosmetic compositions and which provide protection against UV radiation to a significant extent.
10 The present inventors have found that ultraviolet light absorbing silicone compounds containing chains of silicone base polymers, covalently attached to at least one of organic UV-A or UV-B sunscreen, while being covalently bound to each other through difunctional spacer groups, unexpectedly solves the problems
15 associated with the synthesis and the ease of incorporation of these compounds in cosmetic compositions, while significantly reducing transdermal migration of sunscreens and also improved substantivity.
20 OBJECT OF THE INVENTION
It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.
2 5 It is an object of the present invention to provide ultraviolet
light absorbing silicone compounds, which are relatively easy to incorporate in cosmetic compositions.
It is an object of the present invention to provide ultraviolet
3 0 light absorbing silicone compounds, which provide protection
against UVA and UVB radiations.
SUMMARY OF THE INVENTION
According to an aspect of the invention there is provided an
35 ultraviolet light absorbing silicone compound of the general formula:

- 5 -


.i^/'+o^m

10
15

where Rl is straight or branched alkyl, cycloalkyl,
polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl,
aralkyl, alkenyl, alkynyl or fluorocarbon group containing 1
- 50 carbon atoms or any combination thereof;
R2 = Rl or -H, -OH or a group selected from polyethers,
perfluoropolyethers, or an organic moiety containing
nitrogen and/or phosphorous and/or sulfur or
polymer/biopolymer chains,
X is a UV absorbing moiety;
R3 is a spacer group; and
a, b and c are integers from 1 to 200.

According to another aspect of the invention, there is provided an ultraviolet light absorbing silicone compound of the general
20 formula:

- 6 -

R1
.Si X

R1
R1'

R1

-Si

So

R1
.Si

R1
Ho/lWo^-W

R1
Si'

-R1

10
15

where Rl is straight or branched alkyl, cycloalkyl,
polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl,
aralkyl, alkenyl, alkynyl or fluorocarbon group containing 1
- 50 carbon atoms or any combination thereof;
R2 = Rl or -H, -OH or a group selected from polyethers,
perfluoropolyethers, or an organic moiety containing
nitrogen and/or phosphorous and/or sulfur or
polymer/biopolymer chains;
X is a UVA absorbing moiety;
Y is a UVB absorbing moiety;
R3 is a spacer group; and
a, b, c and d are integers from 1 to 2 00.

20

According to another aspect of the invention, there is provided a process for preparing an ultraviolet light absorbing silicone compound comprising the step of:
reacting a compound-1 having the general formula;
Rl R2 Rl R1-.
-CH
-Si.
\-E1
Rl
H
i'°+si-
Rl

25

where Rl is straight or branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl,

- 7 -

5 aralkyl, alkenyl, alkynyl or fluorocarbon group containing 1 - 50 carbon atoms(s) or a combination thereof; R2 is an alkyl group and p is an integer from 2 to 400, with at least one UV absorbing moiety having a terminal reactive group, that bind covalently to compound-1, in the presence
10 of a spacer compound selected from the group consisting of mono alkenyl polyethers; alpha, omega dienes; alpha, omega diynes; alpha, omega ene- ynes and alkenyl or alkynyl terminated polysiloxanes, in the presence of a catalyst and optionally in the presence of an organic solvent or a
15 silicone fluid.
According to another aspect of the invention there is provided a process for preparing an ultraviolet light absorbing silicone compound comprising the step of:
20 reacting a compound-1 having the general formula;
R1 R2 R1 R1
-Si.
Rl H Rl
-O-Si
si-°
where Rl is straight or branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, alkynyl or fluorocarbon group containing 1
25 - 50 carbon atoms(s) or a combination thereof;
R2 is an alkyl group and p is an integer from 2 to 400, with a UVA absorbing moiety and a UVB absorbing moiety each having a terminal reactive group, which binds covalently to said compound-1, in the presence of a spacer compound
30 selected from the group consisting of mono alkenyl
polyethers; alpha, omega dienes,• alpha, omega diynes,• alpha, omega ene- ynes and alkenyl or alkynyl terminated polysiloxanes in the presence of a catalyst and optionally in the presence of an organic solvent or a silicone fluid.
35

- 8 -
5 According to another aspect of the invention, there is provided a cosmetic composition comprising an ultraviolet light absorbing silicone compound of the invention.

10

The invention will now be described in greater detail.
DETAILED DESCRIPTION
According to one aspect, the present invention relates to ultraviolet light absorbing silicone compounds.

15 These silicone compounds are synthesized by reacting Si-H
containing siloxanes and / or polysiloxanes (linear or cyclics) with alkenyl or alkynl functional ultraviolet absorbing compounds in the presence of difunctional spacer compounds having alkenyl or alkynyl groups, in the presence of a suitable catalyst, optionally
20 in the presence of organic and / or silicone based solvent.
The Si-H containing siloxanes, which are used as the base polymers can be represented by the following general formula:
R1 R2 R1
R1.
Si'°
-Si..
/ I \ ^
Rl H R1
,0-Si
\ -n-J ,-0-
P
25 where Rl is straight or branched alkyl, cycloalkyl,
polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, alkynyl or fluorocarbon group containing 1-50 carbon atoms(s) or a combination thereof; R2 is an alkyl group and p is an integer from 2 to 400. Preferably
30 R1 and R2 are short chain alkyl groups selected from methyl,
ethyl, propyl or butyl groups, more preferably all Rl groups are methyl groups.
UV-A absorbing moiety is preferably selected from alkenyl or 35 alkynyl functional derivatives of one or more of benzophenone,

- 9 -
5 dibenzoylmethane, diarylbutadiene, curcumin or triazine. UVB
absorbing moiety is preferably selected from alkenyl or alkynyl functional derivatives of one or more of aminobenzoic acid, cinnamic acid, salicylic acid, benzylidene camphor, malonates, phenyl benzimidazole, cyanoacrylates, diphenyl-acrylate, triazine,
10 triazole or vinyl group-containing amides.
Preferred aminobenzoic acid derivatives are selected from 4-aminobenzoic acid, 4-aminobenzoic acid-2,3-dihydroxypropyl ester, 4-[bis(2-hydroxypropyl)-amino]benzoic acid ethylester, 4-
15 (dimethylamino)benzoic acid-2-ethylhexylester and ethoxylated 4-aminobenzoic acid ethylester with appropriate structural modifications.
Preferred cinnamic acid derivatives are selected from p-methoxy- 20 cinnamic acid-2-ethylhexylester, 4-methoxy-cinnamic acid
isopentylester, 4-methoxy-cinnamic acid-2-methylhexylester and diethanolamine salt of 4-methoxy-cinnamic acid with appropriate structural modifications.
25 Preferred Salicylic acid derivatives suitable include 2-ethylhexyl salicylate, 4-isopropyl-benzylsalicylate and 3,3,5-trimethylcyclohexyl-salicylate, whereas preferred benzylidene camphor derivatives include 3-(4'-methyl-benzylidene)-dl-camphor and 3-benzylidene camphor with appropriate structural
30 modifications.
Preferred phenylbenzimidazole derivatives include 2-phenylbenzimdazole-5-sulfonic acid and its potassium, sodium and triethanolamine salts, while diphenylacrylate derivatives include
35 2-cyano-3,3'-di-phenylacrylic acid-2-ethylhexylester and 2-cyano-3,3'-diphenylacrylic acid ethylester with appropriate structural modifications.

- 10 -
5 The triazole derivatives are preferably selected from 2-(2-hydroxy-5-methylphenyl) benzotriazole, malonate derivative are preferably selected from p-methoxy benzal diethyl malonate, p-methoxy benzal diisobutyl malonate, cinnamal diethyl malonate, indolal diethyl malonate, fural diethyl malonate, 3,4,5 trimethoxy
10 benzal diethyl malonate or p-allyloxy benzal diethyl malonate with appropriate structural modifications.
Preferred cyanoacrylate derivatives include 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, 2-ethyl, 2-cyano-3,3-diphenylacrylate,
15 (acetoxyalkyl) 2-cyano-3,3-diphenylacrylate, 2-ethylhexyl 2-cyano-3-phenylacrylate, 2-ethyl 2-cyano-3-phenylacrylate or
(acetoxyalkyl) 2-cyano-3-phenylacrylate, while preferred benzophenone derivatives include 2-hydroxy-4-methoxybenzophenone , 2-hydroxy4-methoxybenzophenone-5-sulfonic acid and its sodium salt
20 and 8-(2, 2'-dihydroxy-4-meothxybenzophenone) with appropriate structural modifications.
Preferred benzoylmethane derivatives and dibenzoylmethane derivatives include 1-(4-tert-butylphenyl)3-(4-methoxyphenyl)-
25 propane-l, 3-dione and 4-isopropyidibenzoylmethane, 2-methyldibenzoylmethane, 4-methyldibenzoylmethane, 4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane, 2,4-dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane, 4,4'-diisopropylbenzoylmethane, 4-tert-butyl-4'-
30 methoxydibenzoylmethane, 2-methyl-5-isopropyl-4'-methoxydibenzoylmethane, 2-methyl- 5 -tert-butyl- 4 ' -methoxydibenzoylmethane, 2,4-dimethyl-4'-methoxydibenzoylmethane and 2,6-dimethyl-4'tert-butyl-4'methoxydibenzoylmethane with appropriate structural modifications.
35
The base silicone polymer chains are covalently linked to each other through difunctional spacer groups. These difunctional spacer groups prevent excessive and three dimensional

- 11 -
5 crosslinking, which leads to a gelled mass. Instead they help in forming a crosslinked elastomeric compound that is relatively easier to incorporate in cosmetic compositions. Preferred spacer
compounds are selected from di alkenyl polyethers, alpha, omega
dienes, alpha, omega diynes; alpha, omega ene- ynes or di alkenyl
10 or dialkynyl terminated polysiloxanes. Suitable examples of alpha, omega-dienes are 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene; 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, 1,13-tetradecadiene and 1,19-eicosadiene. Suitable examples of alpha, omega-diynes are 1,3-butadiyne or 1,5-hexadiyne, whereas alpha,
15 omega ene-yne is preferably hexene-5-yne. It is preferred that the spacer groups are siloxane based.
Di-alkenyl terminated polysiloxanes, useful as spacer groups according to the invention can be represented by the following
20 general formula:

■Si-
Si
k°-
/
R' V R

wherein R is straight or branched alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, alkaryl, alkoxy, aryl, aralkyl, alkenyl, or alkynyl or fluorocarbon group containing
25 approximately 1 to approximately 50 carbon atoms(s) and
combinations thereof; where p is an average and is a number with a value in the range of 20-1000 (corresponding to an average molecular weight of 1500-75,000 daltons) (with more particular values for r being in the range of 300-500, corresponding to an
30 average molecular weight in the range of 22,000-40,000 daltons,-and a particular vinyl terminated polysiloxane having r = 375, a molecular weight of 28,000 and a viscosity of 1000 cps); and 0.2 weight % vinyl content. R19, R23 are the monovalent unsaturated hydrocarbon radical having 2 to 12 carbon atoms, such as allyl,
35 vinyl; preferably vinyl and R18, R2 0, R21, R22 and R24 are the monovalent hydrocarbon radicals (CI to CIO monovalent

- 12 -
5 hydrocarbon), preferably from the group consisting of methyl, ethyl, propyl, isopropyl etc; most preferably methyl.
The di-alkenyl terminated polyethers can be represented by the following general formulae:

10

R = divalent moiety

Catalysts
It is preferred that the addition reaction between the alkenyl or alkynyl terminated UV absorbing moeties, the alkenyl or alkynyl
15 terminated spacer compounds and the Si-H functional silicone base polymer chains is carried out in the presence of a suitable addition catalyst. These are selected from metal complexes or their compounds or metals in free or immobilized form. Transition metals such as Platinum, Palladium and Rhodium are particularly
20 preferred. Preferred catalysts are Chloroplatinic acid, complexes of Platinum with unsaturated compounds e.g. Platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex; Platinum(O)-2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane complex; Pt0(l,5 cyclooctadine) i.e. Pt(COD)]; Platinum Phospine complexes;
25 Platinum on Carbon; Platinum on inorganic supports such as silica and Platinum black. Other metals such as palladium, rhodium complexes were also used for the reaction (for examples Wilkinson's catalyst RhCl [(C6H5) P]3. More Preferred catalysts are metal complexes or compounds or free metals or immobilized
30 form of Transition metals such as Platinum, Palladium, Rhodium, Preferable catalysts are Chloroplatinic acid, complexes of

- 13 -
5 platinum with unsaturated compounds. The catalyst can be in heterogeneous phase, e.g., on charcoal or, preferably, in homogeneous phase (Karstedt catalyst). Platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex was used most preferably.
10 Solvents and Swelling agents
The reaction between silicone base polymer, UV absorbing moieties and spacer is optionally carried out in the presence of a solvent selected from water, a silicone fluid; polar organic compounds, non-polar organic compounds and mixtures thereof. Typically the
15 solvent is present in an amount of 0. 1 to 99.89 wt. % based on
the weight of all components. Preferably the solvent is present in an amount of from 1 to 80 wt. % and more preferably from 1 to 50 wt. %. When the solvent is a polar or no-polar organic compound it is preferred that the amount to be used is that which would create
20 a product containing <40 wt. % solids.
When used, the solvent becomes an integral part of the resulting elastomer composition and affects the structural and physical properties of the silicone elastomer. Preferably the solvent is not removed from the silicone elastomer composition.
2 5 Silicone fluids useful as the solvent include, but are not limited
to alkyl and/or aryl siloxanes such as methyl siloxanes and alkyl and/or aryl siloxanes containing functional groups wherein the functional groups do not react with or substantially change the reaction between Z and Z'. Preferred are volatile methyl siloxanes
3 0 (VMS). VMS compounds correspond to the average unit formula
(CH3)jSiO(4-j)/2 in which j has an average value of 2 to 3. The VMS compounds contain siloxane units joined by Si--0--Si bonds.
Representative linear volatile methyl siloxanes include, but are not limited to, hexamethyldisiloxane, octamethyltrisiloxane,
35 decamethyltetrasiloxane, dodecamethylpentasiloxane,
tetradecamethylhexasiloxane, and hexadecamethylheptasiloxane.

- 14 -
5 Representative cyclic volatile methyl siloxanes are
hexamethylcyclotrisiloxane; octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane; and dodecamethylcyclohexasiloxane.
The silicone fluid useful herein also includes using silicone fluids represented respectively by formulas R 3SiO (R2SiO) nSiR3 and
10 (R2SiO) p wherein R is as defined above. The value of subscript n is 0-80, preferably 5-20. The value of subscript p is 3-9, preferably 4-6. These polysiloxanes have a viscosity generally in the range of about 1-100 mm2/s. Silicone fluids can also be used where n has a value sufficient to provide siloxane polymers with a
15 viscosity in the range of about 100-1, 000 mm 2/sec. Typically, n can be about 80-375. Illustrative of such silicone fluids are polydimethylsiloxane, polydiethylsiloxane, polymethylethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane.
2 0 Functional silicone fluids can also be employed as the solvent.
Polar organic compounds useful herein include monohydroxy alcohols such as ethyl alcohol and isopropyl alcohol; diols and triols such as propylene glycol, 2-methyl-1,3-propane diol HOCH 2CH(CH3) CH2OH, 1,2-hexanediol CH3 (CH2) 3CH(OH)CH20H, and glycerol; glycerol esters 25 such as glyceryl triacetate (triacetin), glyceryl tripropionate (tripropionin), and glyceryl tributyrate (tributyrin); and polyglycols such as polyethylene glycols and polypropylene glycols, among which are PPG-14 butyl ether C4H9 [OCH (CH3) CH 2] i40H.
Non-polar organic compounds may also be used as the diluent. The
3 0 non-polar organic compounds include aromatic hydrocarbons,
aliphatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols, glycol ethers, alkyl halides, or aromatic halides. Representative compounds are alcohols such as methanol, ethanol, 1-propanol, cyclohexanol, benzyl alcohol, 2-octanol, 35 ethylene glycol, propylene glycol, and glycerol

- 15 -
5 Suitable organic solvents are the ones that do not undergo a chemical reaction with any of the components of the silicone phase, under the anticipated conditions of processing and use and that is suitable for use in the intended end-use application.
The reaction temperature, depending upon the reactants, is in the
10 range of 5 to 200°C and preferably about 80 - 120°C and most preferably 110°C. The reaction time could vary between 1 minute to about 48 hours.
According to yet another aspect, the present invention relates to
15 a cosmetic composition comprising the ultraviolet radiation absorbing silicone compound according to the invention, in a cosmetically acceptable vehicle. It is preferred that the compound is present from 1 to 3 0% by weight of the composition, more preferably from 2 to 15% and most preferably from 3 to 10% by wt
2 0 of the composition. These could be suitable for the protection of
human skin and/or hair from damaging effects of UV radiation.
The cosmetic compositions of the invention are useful as compositions for photo protecting the human epidermis or hair against the damaging effect of UV irradiation, as
25 antisun/sunscreen composition or as makeup product. Such
compositions can, in particular, be provided in the form of a lotion, a thickened lotion, a gel, a cream, cleansing milk, an ointment, a powder or a solid tube stick and may optionally be packaged as an aerosol and may be provided in the form of a
3 0 mousse, foam or a spray.
The cosmetic compositions of the invention can also contain usual cosmetic adjuvants and additives commonly employed in skin care products such as liquid or solid emollients, silicone oils, emulsifiers, solvents, humectants, polymeric or inorganic 35 thickeners, powders, organic or inorganic sunscreens, skin
lightening agents, skin conditioners, optical brighteners, propellants, healing agents (example allantoin), cooling agents

- 16 -
5 (example urea, menthol, menthyl lactate, frescolate), antiseptic agents and other specific skin-benefit actives. The vehicle may also further include adjuncts such as antioxidants, perfumes, opacifiers, preservatives, colorants and buffers. The necessary amounts of the cosmetic and dermatological adjuvants and additives
10 can, based on the desired product, easily be chosen by the skilled person.
The composition can additionally comprise from 0.1 % to 10%, more preferably from 0.1 % to 5 % of an inorganic sunscreen agent e.g.
15 titanium dioxide, zinc oxide or silica such as fumed silica and mixtures thereof.
Emollients, such as stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, stearic acid, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl
2 0 laurate could be used in the compositions. The emollient is
preferably present in an amount from about 1 wt.% to about 20 wt.%, preferably from about 2 wt.% to about 15 wt.%, and most preferably from about 4 wt.% to about 10 wt.% of the total weight of the composition.
25 The preservatives and antioxidants are preferably present in an amount ranging from about 1 wt. % to about 10 % of the total weight of the composition. Preferably, the preservatives and/or antioxidants are present in an amount varying from about 0.1 wt. % to about 1 wt. %
3 0 Moisturizing agents, such as humectants, may be incorporated into
the compositions according to the present invention to reduce the trans- epidermal water loss (TEWL) of the horny layer of the skin. Suitable humectants include glycerin, lactic acid, pyrrolidone carbonic acid, urea, polyethylene glycol, polypropylene glycol,
35 sorbitol, PEG- 400, and mixtures thereof. Additional suitable
moisturizers are polymeric moisturizers of the family of water soluble and/or with water gelating polysaccarides such as

- 17 -
5 hyaluronic acid, chitosan and/or fucose rich polysaccharides available, e.g., as Fucogel1000 (CAS-Nr. is 178463-23-5) from SOLABIA S. The moisturizing agent is optionally present in an
amount varying from about 0.5 wt. % to about 8 wt. %, preferably from about 1 wt. % to about 5 wt. % of the total weight of the
10 composition.
Suitable neutralizing agents which may be included in the composition of the present invention to neutralize components such as e.g. an emulsifier or a foam builder/stabilizer include but are not limited to alkali hydroxides such as a sodium and potassium
15 hydroxide) organic bases such as diethanolamine (DEA), triethanolamine (TEA), aminomethyl propanol, trisodium ethylenediaminetetraacetic acid and mixtures thereof; basic amino acids such as arginine and lysine and any combination of any of the foregoing. The neutralizing agent may be present in an amount
20 of about 0.01 wt.% to about 8 wt.% in the compositions of the present invention, preferably, 1 wt.% to about 2 wt.%. Electrolytes could be present in an amount of about 0.01 wt. % to about 0.5% wt. in the compositions of the present inventions.
2 5 The invention will now be explained in detail with help of the
following non-limiting examples, which form preferred embodiments of the various aspects of the invention.
A general scheme of synthesis adopted by the present inventors is
3 0 given below. Specific examples synthesized by the present inventors
are also given below.

- 18 -

Me Me Me Me
^r0^lro^s^o^_Me MHPS copolymer
MC H \ Me
Me
EFZ
Reactive UV chromophores

Q OH

Allyloxy functional
dibenzoylmethane sunscreen
(UVA)

and/or


EtO
and/or

Allyloxy functional cyanoacrylate sunscreens (UVA1)

Allyloxy functional
Malonate sunscreen
(UVB)

Reactive spacer or cross-linker

Me
Me r / ^n

Me

Divinyl terminated Polysiloxane (VTP)

Me

Me

Me

and/or

Divinyl terminated poly(ethylene glycol)

Hydrosilylation Reaction

Platinum Catalyst

Actives or other additives

Swelling agent/Solvents


UV absorbing gel (containing covalently linked UVA & UVB chromophores)

- 19 -

f%

UVA

O

OH

\\ /

0"(CH2)3

(CHA
in

Example-1
Synthesis of ultraviolet light absorbing silicone compound having 10 UV-B absorbing moiety belonging to the malonate class and UVA
absorbing moiety belonging to the Dibenzoylmethane class with a siloxane spacer.


Me
/
Me
Swelling agent
Me M
Me Me
Me
Me
Me
Me
Me
Me-Me'
UVA
Me
UVB
CH,
H2C
-Si-
r
Me'
^ -Me
LOJ
UVB
Me—-SJ-Me CH2 CH,
UVA
/ Me /
Me Me Me Me
Me
Me

Silicone elastomer Gel swollen with D,

15

20

This silicone compound was synthesized in five stages.
Stage 1: Synthesis of allyloxy functional UV-B sunscreen of
malonate class.
Stage 2: Synthesis of allyloxy functional UV-A sunscreen of
dibenzoylmethane class

- 20 -
5 Stage 3: Synthesis of methylhydrogenpolysiloxane (MHPS) copolymer.
Stage 4: Synthesis of divinyl terminated polysiloxane copolymer
(VTP) spacer.
Stage 5: Hydrosilylation and Swelling
10 Stage 1) was a two-step process.
Step a: Synthesis of Allyloxy Benzaldehyde
A mixture of 4-hydroxybenzaldehyde (10 g, 0.09 M) and Potassium carbonate (20g, 0.145 M) was prepared in 200 ml Acetone. The
15 reaction mixture was refluxed for 2 hours to form potassium salt
of 4-hydroxy benzaldehyde. Allyl chloride (40 ml) was added over a period of 3 - 4 hours and the mixture was further refluxed for -20 hrs. The progress of the reaction was checked by TLC. The reaction mass was cooled to room temperature after TLC showed absence of
20 reactants. The mass was filtered and the residue was washed thrice with 100 ml hot acetone for each wash. The acetone filtrate was concentrated and 100 ml n-Chloroform was added. The Chloroform layer was washed with saturated Sodium chloride solution followed by distilled water wash till the pH of the solution was neutral.
25 The organic hexane layer was dehydrated over anhydrous Sodium sulfate and concentrated.
The resultant product was clear, transparent brownish liquid and the yield of reaction was about 92%.
30 Step b: Reaction of" Allyloxy Benzaldehyde with diethyl Malonate.
In a reaction assembly fitted with Dean-Stark apparatus, a mixture of 0.48 g (0.0056 M) Piperidine and 0.35 g (0.0056 M) Acetic acid in 3 0ml Benzene, Diethyl, malonate 8.05g (0.05 M) and Allyoxy
35 benzaldehyde 6g (0.037 M) were added. Water was removed
azetropically by maintaining the reaction mass at reflux temperature of Benzene for -14 hours. The progress of the reaction was monitored by TLC. The reaction mass was washed with distilled

- 21 -

5 water (3X100 ml), followed by washes with IN HC1 and saturated Sodium bicarbonate solution. The organic layer was washed till neutral pH & dehydrated over Na2S04. The dehydrated layer was concentrated.
10 Yield of the product was about 90% and its structure is:
OEt
0 -OEt

allyloxy functional UV-B sunscreen of malonate class
Stage 2) Synthesis of allyloxy-functional UV-A sunscreen of dibenzoylmethane class
This synthesis was carried out in two steps - a and b.
15
Step a: Synthesis of p-allyloxy Acetophenone
A suspension of 4-hydroxy Acetophenone 10 g and anhydrous Potassium carbonate (2 0g) was prepared in 200 ml Acetone. The reaction mixture was refluxed for 2 hours to form potassium salt
20 of 4-hydroxy acetophenone. Allyl chloride (40 ml) was added over a period of 3 - 4 hours and the mixture was further refluxed for 20 hrs. The progress of the reaction was monitored by TLC. The reaction mass was cooled to room temperature after TLC showed absence of reactants. The mass was filtered and the residue was
25 washed thrice with 100 ml hot acetone for each wash. The acetone
filtrate was concentrated and 100ml n-Hexane was added. The Hexane layer was washed with saturated Sodium chloride solution followed by distilled water wash till the pH of the solution was neutral. The organic hexane layer was dehydrated over anhydrous Sodium
30 sulfate and concentrated. This product was used without re-crystallization for the next stage.
Step b: Reaction of p-tertiary butyl methyl benzoate with p-allyloxy Acetophenone

- 22 -
5 Methanol (110 ml) & sodium 2.5g (0.1087 M) were mixed at room
temperature under stirring till a clear solution was obtained. In a reaction assembly containing simultaneous addition and distillation facility, Toluene was added and Methanol was completely removed from the solution.
10
16.4 g (0.0852 M) Para tert-butyl methyl benzoate was added to the above reaction vessel and the mixture was stirred for 0.5 hours. A mixture of Para allyoxy acetophenone 15 g (0.0852 M) & toluene was then added over a period of 2 hours, while continuously adding
15 toluene and removing Methanol which is the by product of the
reaction. The progress of this reaction was monitored by TLC. The reaction time was approximately 5-6 hours, after which 125 ml toluene was added and the reaction mass was washed with IN HC1. Reaction mass was further washed with water till pH of the aqueous
20 layer was neutral. The organic layer was dried over anhydrous Sodium sulfate and concentrated. The crude product was recrystallized from n-hexane.
The product obtained was a pale yellow solid, yield of which was 92%.
allyloxy functional UV-A sunscreen of dibenzoylmethane class
25 The structure of allyloxy functional dibenzoylmethane sunscreen shown above is of the enol tautomer of the compound. The compound can also exist in the corresponding keto form.
30 Stage 3. Synthesis of methylhydrogen-polysiloxane (MHPS) copolymer
50 g of octamethycyclotetrasiloxane (D4) was mixed with 15 g of methylhydrogen-polysiloxane (Aldrich, MHPS) in a two necked round bottom flask. To the mixture 1 g of Tulsion catalyst (Thermax, T63MP) was added. The reaction mixture was stirred at 120 deg C 35 for 4 hours. Viscous MHPS copolymer obtained was cooled down to room temperature. Catalyst was filtered off. Un-reacted D4 was

- 23 -
5 distilled off under vacuum at 125 deg C. The product obtained was colorless - viscous oil.
Me Me Me Me Me-sr°+-^°iTfs('0k-Si-Ma
Me H \ Me
Me
MHPS copolymer Stage 4. Synthesis of divinyl terminated polysiloxane (VTP) copolymer
10 20 g of octamethycyclotetrasiloxane (D4) was mixed with 4 g of divinyltetramethy-disiloxane (Aldrich) in a 50 mL two necked flask. To the mixture 0.3 g of Tulsion catalyst (Thermax, T63MP) was added. The reaction mixture was stirred at 120 deg C for 4 hours. Divinyl terminated polysiloxane copolymer (VTP) copolymer
15 obtained was cooled down to room temperature. Catalyst was
filtered off. Un-reacted D4 was distilled off under vacuum at 125 deg C. The product obtained was colorless - viscous oil. This was used as the spacer compound.

Me Me
20

Me
i -Si
-O
/
-sr
Me \, Me
IVIC Me
Divinyl terminated polysiloxane (VTP) copolymer

Stage 5: Hydrosilylation & Swelling
0.2 g (0.00059 M) allyloxy functional UV-A sunscreen of dibenzoylmethane class (as prepared in stage-2 above); 0.45 g (00148 M) allyloxy functional UV-B sunscreen of malonate class (as
25 prepared in stage-1 above) and 0.3 0 g divinyl terminated
polysiloxane (VTP) (as prepared in stage-4 above) were charged into a moisture-free three necked flask, fitted with as reflux assembly, maintained under Nitrogen atmosphere. 50 ml dry toluene was added subsequently to dissolve all the reagents. Three drops
30 of Platinum catalyst (1,3-divinyltetramethyldisiloxane, Sigma-
Aldrich) were added to the reaction mixture and the mixture was stirred at RT for about 0.5 hours. 3 g of

- 24 -
5 methylhydropolysiloxane (MHPS) copolymer (as prepared in stage-3 above) were added and the reaction was stirred at about 110 °C for about 2-3 hrs. The progress of the reaction was monitored by TLC and FT-IR. The product was obtained in a gel form. The gel was further washed with methanol to remove un-reacted organic matter
10 and Platinum catalyst. It was further swollen in 30 g of
(decamethylcyclopentasiloxane) D5 and remaining traces of toluene and methanol were removed under vacuum below 60 °C. Total mass (33.95g) = Solids (3.95g) + Solvent (30g); %Solid = 11.63; %solvent =88.63
15
The absorbance of a 600 ppm solution of the compound obtained in example-1 showed 2 UV absorption maxima, one at 326 nm with an absorbance value of 0.17 units and the other at 368 nm with a corresponding absorbance value of 0.3 units, thereby confirming
20 the presence of both the UV absorbing moieties.
Comparative example-A
When the reaction was carried out in the absence of any spacer molecule, it was observed that due to excessive cross-linking, the
25 entire reaction mass turned into a gel, which was practically of no usage in cosmetics. The procedure adopted is reported below:
50 g of octamethycyclotetrasiloxane (D4) was mixed with 25 g methylhydrogenpolysiloxane (Aldrich, MHPS) in a two necked round
30 bottom flask. To the mixture 1 g of Tulsion catalyst (Thermax, T63MP) was added. The reaction mixture was stirred at 120 deg C for 4 hours. Viscous MHPS copolymer obtained was cooled down to room temperature. Catalyst was filtered off. Un-reacted D4 was distilled off under vacuum at 125 deg C. The product obtained was
35 colorless - viscous oil. Allyloxy functional UV-A sunscreen i.e. 0.2 g (0.00059 M) allyloxy functional UV-A sunscreen of dibenzoylmethane class (as prepared in stage-2 above) and 0.45 g (00148 M) allyloxy functional functionalized UV-B sunscreen of

- 25 -

5 malonate class (as prepared in stage-1 above) were charged into a
moisture-free reflux assembly, maintained under Nitrogen atmosphere. A Three drops of Platinum catalyst (1,3-divinyltetramethyldisiloxane, Sigma-Aldrich) was added to the reaction mixture and the mixture was stirred at RT for about 0.5
10 hours. A mixture of 3 g Polymethylhydrosiloxane was added to the reaction mixture and the reaction was maintained at about 100°C for about 4 hours hrs. During the reaction cross-linking was observed. This therefore leads to the fact that presence of a spacer compound is important.
15
Example-2:
Synthesis of Ultraviolet radiation absorbing silicone compound having UV-B moiety of the malonate class and UVA moiety of the Dibenzoylmethane class, along with a Polyethyleneglycol emulsifier
20 chain and a siloxane spacer group.
This silicone sunscreen was synthesized in five stages. Stages 1 to 4 of this example are similar to that of the corresponding stages of example-1 described above.
PEG
Me w ^ PEG
Me Me Me Me I Me
^-^°^^0^^0-jFf^.0^L0^rMe
Me UVA \ PEG CH, Me
UVB / 2
H,C
-su.
I P I Swelling agent , ~*^—
Me-Z£=Me pEC? T^ PEG
CH,
iiv» UVB PEG CH2 ci i . r- ,
Me UVA / ; /Me Silicone elastomer Gel
M^0^\-0-U- Vo-kf V-O-U- f °4rsr-Me -oiler, «M> D5
Me Me Me Me I Me
25
Stage 5: Hydrosilylation & Swelling
0.25 g (0.00059M) monoallyloxy terminated poly(ethylene glycol)
(Clariant 20-10 Polygykol) and 60 mL toluene were charged to a
30 three necked flask fitted with a Dean and stark set-up under nitrogen atmosphere. Traces of water present in PEG and toluene

- 26 -
5 where removed by azeotropic distillation. 0.2 g (0.00059 M) allyloxy functional UV-A sunscreen of dibenzoylmethane class (as
prepared in stage-2 above); 0.45 g (0.00148 M) allyloxy functional UV-B sunscreen of malonate class (as prepared in stage-1 above) and 0.30 g divinyl terminated polysiloxane (VTP) (as prepared in
10 stage-4 above) were charged subsequently. Three drops of Platinum catalyst (1, 3-divinyltetramethyldisiloxane, Sigma-Aldrich) were added to the reaction mixture and the mixture was stirred at RT for about 0.5 hours under Nitrogen atmosphere. 3 g. methylhydropolysiloxane (MHPS) copolymer (as prepared in stage-3
15 above) were added to the reaction mixture. The reaction was
maintained at about 110 °C for about 2-3 hrs. The progress of the reaction was monitored by TLC and FT-IR. The product was obtained in a gel form. This gel was further washed with methanol to remove un-reacted organic matter and Platinum catalyst. It was further
20 swollen in 3 0 g of D5 and remaining traces of toluene and methanol
were removed under vacuum below 60 °C.
Total mass (34.15g) = Solids (4.15g) + Solvent (30g);
%Solid = 12.15; %solvent = 87.84
25 The absorbance of a 500 ppm solution of the compound obtained in example-1 showed 2 UV absorption maxima, one at 326 nm with an absorbance value of 0.89 units and the other at 368 nm with a corresponding absorbance value of 0.89 units, thereby confirming the presence of both the UV absorbing moieties.
30
Example-3:
Synthesis of Organofunctional silicone elastomer gel where UV-B chromophore belonged to the malonate class and UVA chromophores belonged to Dibenzoylmethane class with pendant Polyethyleneglycol
35 based self emulsifying chains and Polyethyleneglycol based spacer compound.

- 27 -

Me Me Me Me T Me PEGV^--Tt\ /EG
Me / \ PEG .CH,
UVB ~~ H2C
UVA
I O, I 1 CH2
UVA '
l UVB „.,„ ,CH, Silicone elastomer Gel
MeN \ / J to / Me
Me^^-0-fS!^0^S\^o4rf^-0-^ff'0TB~Sr-Me
Me Me Me Me ^ Me

5 This silicone sunscreen was synthesized in four stages of which stages 1, 2 and 3 are common to that of the corresponding stages of example-1.
10
Stage 4: Hydrosilylation & Swelling
0.25 g (0.00059M) monoallyloxy terminated poly(ethylene glycol) (Clariant 20-10 Polygykol) , 0.2 g divinyl terminated poly (ethylene glycol) (Aldrich) and 60 ml toluene were charged to a
15 three necked flask fitted with a Dean and stark set-up under
nitrogen atmosphere. Traces of water present in PEG derivatives, and toluene where removed by azeotropic distillation. Reaction mixture was cooled to room temperature. 0.3 g (0.00089M) allyloxy functional UV-A sunscreen (as prepared in stage-2 of example-1
20 above); 0.45g (0.00148 M) allyloxy functional UV-B sunscreen of malonate class (as prepared in stage-1 of example-1 above) were charged subsequently. Three drops of Platinum catalyst (1,3-divinyltetramethyldisiloxane, Sigma-Aldrich) were added to the reaction mixture and the mixture was stirred at RT for about 0.5
25 hours. 2.7 g Polymethylhydrosiloxane (MHPS) copolymer was added to the reaction mixture and the reaction was maintained at about 100 °C for about 1.5 - 2 hrs. The progress of the reaction was monitored by TLC and FT-IR. The product was obtained in a gel
form. After the reaction was complete, 30 g of D5 was added and
30 excess toluene was removed under vacuum below 60 °C. The gel was

- 28 -
5 further washed with methanol to remove un-reacted organic matter
and Platinum catalyst.
Total mass (33.90g) = Solids (3.9g) + Solvent (30g);
%Solid = 11.5; %solvent = 88.5.
10 Compounds of the present invention were used to formulate sunscreen compositions, which had the ability to protect skin from both UVA & UVB radiations. Some representative and non-limiting examples of cosmetic cream compositions prepared in accordance with an aspect of the invention are as follows. The table-1 below represents the compositions according to the invention.
Table-1

Ingredients Code Code Code
Ex-4 Ex-5 Ex-6
Phase 1
Compound of Example 1 10 - -
Compound of Example 2 - 10 -
Compound of Example 3 - - 10
D5 (Decamethylcyclopentasiloxane) 5 5 5
Silicone emulsifier 5225C (Dow) 3 3 -
Phase 2
Vit-E - - 0.1
Iso Propyl Myristate ' - - 0 .1
Phenoxy ethanol - - 0.1
Phase 3 (aqueous phase)
Water 20 35 35
Niacinamide - - 0.5
Glycerin - - 0.2
Other minors To 100 To 100 To 100

- 29 -
5 Procedure for preparing skin care creams
Although creams and other cosmetic preparations could be made by known methods, a representative and non-limiting example of the procedure adopted by the present inventors is given below. Ingredients from phase 1& 2 were mixed and homogenized for 10
10 minutes. Viscosity of this phase was controlled by changing quantity of D5. Phase 3 was prepared separately at room temperature. Aqueous solution of phase 3 was added slowly to phase under homogenized condition. Creams were obtained at room temperature.
15
Absorbance measurements were carried out to study the absorbance characteristics of the compounds used in the formulations. Absorbance was measured for Example-5 by preparing dilute solutions as reported under in the following table-2.
20
Table-2

Absorbance(A) 800 ppm 500 ppm 2 00 ppm
Ex-5 3 26 nm 0.2 0.11 0.04
3 68 nm 0.21 0.13 0.04i r.
Thus it can be readily seen that the compound synthesized according to the invention after formulating a cosmetic composition using it, remains active and continues to absorb UVA and UVB radiation.
30 Substantivity studies:
Substantivity studies were conducted to determine the efficacy of the ultraviolet radiation absorbing silicone compounds synthesized according to the invention and used in a formulation, namely Composition of example-5.

- 30 -
5 The efficacy of this compound was tested against marketed sun- care products.
SHISEIDO® White Lucent brightening protective moisturizer (Formulation 3)
AVIANCE® Beauty Solutions White essence skin enhancing fluid 10 (Formulation 4)
FAIR & LOVELY® ACTIVE SUNBLOCK (Formulation 5)
Basic Principle behind the experiment
Glass plates coated with TINASORB (a blue fluorescer molecule) were 15 used for these studies. Upon irradiation with UV light onto the
coated glass plates, a blue fluorescence is observed. When the UV radiation is prevented from reaching a part of the coated glass surface, by means of a UV blocking agent, blue fluorescence is not observed in that part and such part appears dark.
20
Glass plate - I was coated with Tinasorb. Upon UV irradiation, blue fluorescence could be seen from this. This is depicted in figure-A of figure -1 below.
25 Glass plate - II was coated with a film of cosmetic cream without any sunscreens. Glass plate II was then placed on glass-plate I. The fluorescence obtained from "Glass plate - I coated with Tinasorb" through Glass plate-II was again observed under UV light (figure B). Fluorescence could be seen.
30
Glass plate III coated with a film of FAIR & LOVELY ACTIVE SUNBLOCK cream was place on glass-plate I. The fluorescence obtained from "Glass plate - I coated with Tinasorb" through Glass plate - III was again observed under UV light (this has been depicted in figure
35 C). The film of the cosmetic composition containing sunscreens
prevents UV radiation from reaching the Glass Plate-1, therefore preventing fluorescence. This region therefore appears as a dark patch.

- 31 -
5 Glass plate - IV was patterned with alphabets (U, L, I) using
various formulations (containing sunscreens) films. Glass plate IV was place on glass-plate I. The fluorescence obtained from "Glass plate - I coated with Tinasorb" - (through Glass plate - IV) was again observed under UV light (figure D). Dark patches could be
10 seen that corresponded to the alphabets on the Glass plate-IV, where light could not reach the glass surface.
Figure-1 gives a depiction of the glass surfaces upon irradiation with UV light.
15
Substantivity studies
Cosmetic cream composition made according to the invention (Experiment 5) was tested for its efficacy as regards the substantivity of the sunscreen agent against commercially available
20 products (Shiseido, Aviance and Fair & Lovely Active Sunblock)
About 2g of the products (Experiment 5, Shiseido, Aviance & Fair & Lovely Active Sunblock) were taken on clean glass plates and the material was spread to form films. The films were dried for 3
2 5 hours, after which, all glass plates were observed under UV light.
The extent of blue fluorescence was recorded as the T0 (Zero time) reading. The glass coated films were then subjected to sonication for 30 sec and washed under flowing tap-water for 10 sec. The
extent of blue fluorescence was recorded as the T30 reading. The
3 0 same plate was then sonicated for 150 seconds, washed under tap-
water for 10 sec and the extent of blue fluorescence was recorded (T150 reading) . The process was continued for the reading at time 180 sec (T180 reading)
35 The figures indicate that the compositions according to the invention have comparatively higher substantivity than the commercially available products, even at 30 seconds as the applied films were washed off.

- 32 -

5 It will be appreciated that the illustrated examples provide for ultraviolet light absorbing silicone compounds, which are relatively easy to incorporate in cosmetic compositions.
It will be appreciated that the illustrated examples provide for
10 ultraviolet light absorbing silicone compounds, which provide protection against UVA and UVB radiations.
v^WvXioUA^nA
Dated this 20th day of December 2006 HINDUSTAN LEVER LIMITED
S.VENKATRAMANI
(Senior Patents Manager)
0
5