CA2188877A1

CA2188877A1 - Cosmetic compositions

Info

Publication number: CA2188877A1
Application number: CA 2188877
Authority: CA
Inventors: Robert Francis Date; Zahid Nawaz; Eric George Spengler
Original assignee: Individual
Current assignee: Procter and Gamble Co
Priority date: 1994-04-26
Filing date: 1995-04-25
Publication date: 1995-11-02
Also published as: WO1995028913A1; EP0758881A1; CN1150755A; GB9408259D0; MX9605223A; AU2427795A; EP0758881A4; JPH09512277A; CZ315096A3

Abstract

A skin care composition in the form of an oil-in-water dispersion which comprises from 1 % to 60 % oil, from 30 % to 98.8 %
water, from 0.1 % to 20 % urea, and from 0.1 % to 20 % of an organic amphiphilic emulsifier material which is capable of forming liquid crystals in product or on the skin. The composition provides improved moisturization, skin feel and skin care benefits and reduced greasiness, together with excellent rub-in, absorption and stability characteristics.

Description

W0 95/28913 F~ ,3" . - .

Cosmetic ComDositions Technical Field The present invention relates to cosmetic co"l~.osi~ions. In particular it relates to cosmetic Co"l~ osiLiulls in the form of emulsions or lotions which provide improved moisturization, skin feel ,skin care and appddldl~ce benefits and reduced s~,ea~i"dss, together with excellent rub-in and abso".~ion clldlduldri~Lil,s. The coi,,,uG~;Lions also display excellent stability ClldlduL~Iialiua at normal and elevated temperatures.
Background of the Invention Skin is made up of several l~yers of cells which coat and protect the keratin and collagen fibrous proteins that form the skeleton of its structure. The outermost of these layers, referred to as the stratum corneum, is known to be cor"~.osed of 25nm protein bundles surrounded by 8nm thick layers.
Anionic surfactants and organic solvents typically penetrate the stratum corneum "":-"b~d"e and, by de~ ull (i.e. removal of the lipids from the stratum corneum), destroy its intesrity. This destruction of the skin surface LupO~lap~ly leads to a rough feel and may eventual~y permit the surfactant or solvent to interact with the keratin, creating irritation.
It is now recognised that ~c;.~L.,;.~i,~g the proper water gradient across the stratum corneum is important to its fu"uLiùnali~y~ Most of this water, which is s~ld~illles considered to be the stratum corneum's plcu~Li~ dl, comes from inside the body. If the humidity is too low, such as in a cold climate, insufficient water remains in the outer layers of the stratum corneum to properly plasticize the tissue, and the skin begins to scale and becomes itchy. Skin p~ y is also decreased somewhat when there is inadequate water across the stratum corneum. On the other hand, too much water on the outside of the skin causes the stratum corneum to ultimately sorb three to five times its own weight of bound water. This swells and puckers the skin and results in c,u~,ru~.i"~dLcly a two to three foldincrease in the p~,ll ~~' ' Ly of the skin to water and other polar molecules.
Thus, a need exists for co,,,~,osiLiuns which will assist the stratum corneum in ~"e.;.,L~.;., ,9 its barrier and water-reteQtion functions at optimum wogS/28913 r~l~e~ 0~

pe, rur~al)ce in spite of deleterious interactions which the skin may encounter in washing, work, and recreation.
Conventional cosmetic cream and lotion compositions as described, for example, in Sagarin, Cosmetics Science and Technology, 2nd Edition, Vol.l, Wiley l"L~ nce (1972) and Encyclopaedia of Chemical Technology, Third Edition, Volume 7 are known to provide varying degrees of emolliency, barrier and water-retention Imoisturizing) benefits. However, they can also suffer serious negatives in terms of skin feel (i.e. they often feel very greasyon the skin) as well as having poor rub-in, absorption and residue ClldlaLL~ .s.
The present inventiùn therefore provides skin-care cosmetic compositions which provide improvements in moisturization, absorption, skin feel, skin care and cpp~d~a~ a,d.,~ ,Li~s and which in particular provide improved short and longer term moisturizing effectiveness, while at the same time reducing stickiness and avoiding a greasy feel on the skin. The compositions also display excellent stability chard..L~ri~Li.,:, at both normal and elevated temperatures.
Summarv of the Invention ~
Acco,~;nul~, in one aspect of the present invention, there is provided a skin care co",~,o~iLiol- in the form o~ an oil-in-water emulsion co,,,~u,i~;llg:
(a) from about 1% to about 60% by weight of oil;
(b) from about 30% to about 98.8% by weight of water;
(c) from about 0.1% to about 20% by weight of urea; and (d) from about 0.1% to about 20% by weight of an organic liquid crystal-forming amphiphilic emulsifier material.
The culllpO~iLio~s of the present invention take the form of an oil-in-water emulsion or disp6~;0l1 conLci,~i,,g cne or more distinct emulsified or dispersed oil phases together with urea and an essential liquid crystal-forming emulsifier co"~pol~"L as well as various optional ingredients as indicated below. All levels and ratios are by weight of total composition, unless otherwise indicated. Chain length and degrees of ethoxylation are also specified on a weight average basis.
.. _ . . . .. . _ _ .. _ , WO 95128913 2 1 8 8 8 7 7 r~

A first essential component of the ~o~posi~ions herein is an oil or mixture of oils. In physical terms, the cO"Ipo~ilions yenerally take the form of a dispersion of one or more oil phases (referred to herein as primary phase secondary phase etc) in an aqueous continuous phase each oil phase comprising a single oily colllpo~1el~ or a mixture of oily col"pol~e"L~ in miscible or ho"~o~ eous form. The overall level of oil phase co",pone"~ in the col"~iLiu,~s of the invention is preferably from about 1% to about 60%, preferably from about 2% to about 30% and more preferably from about 3% to about 20% by weight. In preferred embodiments, the primary oil phase is present in an amount of from about 4% to about 16%, more preferably from about 5% to about 11% by weight of co,,,posiLiun. The level of primary oil phase component is found to be valuable herein for achieving optimum moisturization and s"~a~i"ess ~l,a,duL~ Li~s~ The primary oil phase generally comprises a natural or synthetic oil selected from mineral, vegetabie, and animal oils fats and waxes fatty acid esters, fatty alcohols, fatty acids and mixtures thereof having emollient cosmetic properties. The primary oil phase col,,uonellL is pl~r~ldl.ly esse"Li.,lly silicone-free ie contains no more than about 10%, prt:re,d~ly no more than about 5% by weight of silicon-based materials. It will be ~",de,~lùod that the oil phase may contain small levels ~eg. up to about 25% preferably 10%) of oil phase soluble emulsifier ingredients. Such ingredients are not to be considered as oil phase cu,,,pone,,~ from the viewpoint of d~l~llllilli,lg the oil phase level and required HLB. In preferred ~IlIL- ' 11~111~, the overallrequired HLB of the oil phase is from about 8 to about 12 especially from about 9 to about 11 required HL8 being d~l~lllli"ed by summing the individual required HLB values for each component of the oil phase multiplied by its W/W p~luelllage in the oil phase Isee ICI Literature on HLB
system) .
Suitable primary oil phase co~uol~e~ for use herein include for exampleoptionally hydroxy-substituted C8-Cso unsaturated fatty acids and esters thereof, C1-C24 esters of Cg-C30 saturated fatty acids such as isopropyl myristate cetyl palmitate and octyldodecylmyristate (Wickenol 142) beeswax, saturated and unsaturated fatty alcohols such as behenyl alcohol and cetyl alcohol, hydrocarbons such as mineral oils petrolatum and squalane, fatty sorbitan esters (see US-A-3988255 Seiden issued October -WO95/28913 A 2~ 88877 r~
26 1976), lanolin and lanolin deriYatives, animal and vegetable triglycerides such as almond oil, peanut oil, wheat germ oil, linseed oil, jojoba oil, oil of apricot pits, walnuts, palm nuts, pistachio nuts, sesame seeds, rapeseed, cade oil, corn oil, peach pit oil, poppyseed oil, pine oil, castor oil, soybean oil, avocado oil, sa~flower oil, coconut oil, hazelnut oil, olive oil, y,dpeseedoii, and sunflower seed oil and C1 C24 esters of dimer and trimer acids such as diisopropyl dimerate, diisostearylmalate, di;sGa~t:alyldimerate and llii~o,l~:àryltrimerate. Of the above, highly preferred are the mineral oils, petrolatums, unsaturated fatty acids and esters thereof and mixtures thereof.
Compositions herein preferably also comprise a secondary oil phase which in preferred e",bod;-"~"L~ is present in a level of from about 0.1/0 to about 20%, especially from about 1% to about 10% by weight of con",osiLion.
Moreover, the primary oil phase is preferably present in wei~qht excess of the secondary oil phase. The secondary oil phase cril,,,uonr~lll is preferably silicone-based. Suitable silicone co"~ol-e"l~ herein include water-insoluble silicones inclusive ~f non-volatile polyalkyl and polyaryl siloxane ~ums and fluids, volatile cyclic and linear polyalkylsil~"~a,~e~, polyalkoxylated silicones, amino and quaternary ammonium modified silicones, rigid cross-linked and reinforced silicones and mixtures thereof. In preferred embodiments the silicone component is a silicone gum having a molecular weight of from about 200,000 to about 4,000,000 or a mixture of silicones including the silicone gum. In mixtures, the silicone gum pl~ftllaiJI~ constitutes from about 5% to about 40%, especially from about 10% to 20% by weight of the silicone mixture. The silicone or silicone mixture preferably constitutes from about 0.1% to about 20%, more preferably from about 0.5% to about 15%, and especia~ly from about 1% to about 10% by weight of composition .
A preferred silicone component for use herein consists dsse"L:~lly of:
li) a silicone l1aving a molecular weight of from about 200,000 to about 4,000,000 selected from ~;",e~l,;.,onol, fluorosilicone and di",~Ll,icone ând mixtures thereof; and WO 95/28913 ~._111),. _. . -21 88~77 a silicone-based carrier having a viscosity from about 0.65 mm2.s~
1 to about 100 mm2.s-1, wherein the ratio of i) to ii) is from about 10:90 to about 20:80 and wherein said silicone component has a final viscosity of from about 500 mm2.s~1 to about 10,000 mm2.s-1.
Di",~Ll,i~,onol-based silicones suitable for use herein have the chemical structure (Il):
HO~CH3)2SiO~CH3)2SiO]n~CH3)2SiOH
where n is from about 2000 to about 40,000, preferably from about 3000 to about 30,000.
The fluo~ es useful herein have a molecular weight of from about 200,000 to about 300,000, preferably from about 240,000 to about 260,000 and most preferably about 250,000.
The silicone gums include " "~:LI,icones as described by Petrarch and others including US-A-4,152,416, May 1, 1979 to Spitzer, et al, and Noll, Walter, Chemistrv and TechnolorJv of Silicones. New York: Academic Press 1968.
Also des." ' . ,9 silicone gums are General Electric Silicone Rubber Product Data Sheets SE 30, SE 33, SE 54 and SE 76. "Silicone gum" materials useful herein denote high molecular weight materials having a mass-average molecular weight in excess of about 200,000 and preferably from about 200,000 to about 4,000,000. Typically, they have a viscosity at 25C in excess of about 1,000,000 mm2.s~1. Specific examples include polydimethylailv,~ane, (polydimethylsiloxane) (methylvinylsiloxà,~e) copolymer, poly(dimethyl~ilv,~dne) ~diphenyl) ~methylvinyl;,ilo..a,~e) copolymer and mixtures thereof.
The silicone-based carriers suitable for use herein include certain silicone fluids. The silicone fluid can be either a polyalkyl siloxane, a polyaryl siloxane, a polyalkylaryl siloxane or a polyether siloxane copoiymer.
Mixtures of these fluids can also be used and are preferred in certain executions .

Wo 95128913 2 ~ 8 8 ~ 7 7 r~

The polyalkyl siloxane fluids that can be used include, for example, polydi"~ l,ylsiloxanes with YiSCOsities ranging from about 0.65 to 600,000 mm2.s~1, preferably from about 0.65 to about 10,000 mm2.s~1 at 25C. These siloxanes are available, for example, from the General Electric Company as the Viscasil (RTM~ series and from Dow Corning as the Dow Corning 200 series. The ess6hli211y non-volatile polyalkylarylsiloxane fluids that can be used include, for example, polymethylphenylsilo.~al~es, having v;scoailies of about 0.65 to 30,000 mm2.s~1 at 25C. These siloxanes are available, for example, from the General Electric Company as SF 1075 methyl phenyl fluid or from Dow Cornins as 556 Cosmetic Grade Fluid.
Also suitable for use hereirl are certain volatile cyclic polydimethylsiloxanes having a ring structure i"c~"Jo~ g from about 3 to about 7 ICH3)2SiO
moieties.
The viscosity can be measured by means of a glass capillary ~,;s~,o",~Lt:~ as set forth in Dow Cornins Corporate Test Method CTM0004, July 29, 1970.
F~ t lably the viscosity of the silicone blend constitutins the secondary oil phase ranses from about 500 mm2.s~1 to about 100,000 mm2.s~
1,.preferably from about 1000 mm2.s~1 to about 10,000 mm2.s~1.
The most preferred silicone component for use herein is a ' "t,~l,;c~nol sum havins a moleculâr weisht of from about 200,000 to about 4,000,000 alons with a silicone carrier with a viscosity of about 0.65 to 100 mm2.s~1. An example of this silicone c~",l.olle"~ is Dow Cornins Q2-1403 ~85% 5 mm2.s~1 D:."~ll,icon~ Fluid/15% D;.,l~ll,;conol) and Dow Corning Q2-1401 available from Dow Corning.
Another class of silicone cu,,,~-u,~enL suitable for use herein includepolyd;o"~af ,o~iloxdlle-polyoxyalkylene copolymers co"l~ 6 at least one polydiory~",o~iloxa"e segment and at least one polyoxyalkylene segment, said pol~diur~ osilo~a~e segment con~i ,li"s ess~"i l'y of RbSiO(4-b)/2 .... _ . . _ ....

~ wo9~2S9l3 2 1 88877 r siloxane units wherein b has a value of from about O to about 3, inclusive, there being an averase Yalue of approximately 2 R radicals per silicon for all siloxane units in the copolymer, and R denotes a radical selected from methyl, ethyl, vinyi, phenyl and a divalent radical bonding said polyoxyalkylene se5ment to the polydiorganosiloxane segment, at least about 95% of all R radicals being methyl; and said polyoxyalkyiene segment having an average molecular weight of at least about 1000 and consistins of from about O to about 50 mol percent polyoxypropylene units and from about 50 to about 100 mol percent polyoxyethylene units, at least one terminal portion of said polyoxyalkylene segment being bonded to said polydiorganosiloxane segment, any terminal portion of said polyoxyalkylene segment not bonded to said polydiorganosiloxane segment being satisfied by a ~:llllilld~ill9 radical; the weight ratio of polyui~lyal~Gsilo,.d,~e segments to polyoxyalkylene segments in said copolymer having a value of from about 2 to about 8. Such polymers are described in US-A-4,268,499.
r~rt~ ce for use herein are pol~"~ioryd"G ,iloxd,~e-polyoxyalkylene copolymers having the general formula:
l H3 fH3 CH3 CH3 H3C-- Si --o--(Si--~x ~fi-- O)y--~i-- CH3 CH3 CH3 l 3H6 CH3 o -- (C2H40) a (C3H60) bR
wherein x and y are selected such that the wei~ht ratio of polydiorgano-siloxane segments to polyoxalkalkylene segments is from about 2 to about 8, the mol ratio of a:~a+b) is from about 0.5 to about 1, and R is a chain l~l-llilld~ g group, especially selected from hydrogen; hydroxyl; alkyl, such as methyl, ethyl, propyl, butyl, benzyl; aryl, such as phenyl; alkoxy such as methoxy, ethoxy, propoxy, butoxy; benzyloxy; aryioxy, such as phenoxy; alkynyloxy, =
Wo 9~2ssl3 ~ ~ ~ 8 ~ 7 7 . ~
such as vinyloxy and allvloxy; acyloxy, such as acetoxy, acryloxy and iJ,opionu~y and amino, such as dimethylamino.
The number of and average molecular weights of the segments in the copolymer are such that the weight ratio of polydio,!~dnosilokc,lle segments to polyoxyalkylene segments in the copolymer is preferably from about 2.5 to about 4Ø
Suitable copolymers are available cu"""el.,ially under the ll~d~ s Belsil (RTM~ frûm Wacker-Chemie GmbH, Gescl~d~lab~ icll S, Postfach D-8000 Munich 22 and Abil (RTM) from Th. Goldscl~",idl Ltd., Tego House, Victoria Road, Ruisiip, ~ l95~Y. HA4 OYL.
Particularly preferred for use herein are Belsil ~RTM) 6031 and Abil ~RTM) B88183.
The above polydiorga,loailoxane - polyoxyalkylene copolymers can be used above ûr in admixture with other silicûnes, for example, the volatile cyclic polydimethylsiloxanes. Moreover, such cûpolymers and mixtures can be used in co",' ! laliOIl with the herein defined silicone gums.
The silicone col",uon~"l is valuable herein in conjunction with the liquid crystal-forming emulsifier and urea for modifying the perceived skin feel of the composition. Highly preferred in this respect are silicone gums having a mûlecular weight of frûm 200,000 to 4,000,000. Thus according tû
another aspect of the invention, there is provided a skin care compositiûn in the fûrm of an oil-in-water ~;;.peraiun which co,,,~uliaes a silicone or mixtureof silicones in a level of from 0.1 GJG to 20% by weight, the silicone or âilicone mixture comprising a silicone gum having a molecular weight of from about 200,000 to about 4,000,000 and wherein the COIllpOailiO
additionally inco,,uo,dl~s from about 0.1% to abûut 20% of urea and optionally from about 2 % to about 10 % of an emulsifier capable of forming liquid crystals in water, the preferred emulsifier being a fatty acid ester blend based on a mixture of sorbitan fatty acid ester and sucrose fatty acid ester! The fatty acid ester in each instance is preferably Cg-C24, more preferably C10-C20~ The silicone or silicone mixture is preferably present in a level of from about 0.5% to about 15%, preferably from 1% to about 10% by weight of composition, this level being based on the total blend of W095/28913 P~,lru~, _'~' 21 88~77 gum and non-gum silicone materials. In preferred embodiments the co",~.osiLions of this aspect of the invention comprise a primary oil phase which is essentialiy silicone-free together with a secondary oil phase comprising the silicone gum. The primary oil phase is described in detail above.
Preferred en~h~ ~e~L~ herein comprise from about 0.1% to about 10% by weight of an unsaturated fatty acid or ester. Preferred unsaturated fatty acids and esters for use herein are optionally hydroxy substituted Cg-Cso unsaturated fatty acids and esters especially esters of ricinoleic acid. The unsaturated fatty acid or ester component is valuable herein in Coll~ ld~iOI1 with the liquid crystal-forming emulsifier for improving the skin feel and rub-in ~ I)clac~ LiGs of the co",posilul~. Highly preferred in this respect is cetyl I ;C;I1GI~ Lt: .
A second essential ingredient in the composition herein is an organic amphiphilic emusifier material which is capable of forming liquid crystals in product or when the product is applied on the skin at ambient or elevated temperatures. Preferably the emulsifier is capable of forming liquid crystals (especially smectic Iyotropic liquid crystals) at a temperature in the range from about 20C to about 60C. The emulsifier is preferably illcOl~JOlaLed into the co",l-o~iLio~ in an amount of from about 0.1 % to about 20%
preferably from about 2% to about 10%, and more preferably from about 3% to about 7% by weight of col~uosiLiol~. The alll~ JII emulsifier preferred for use herein is selected from polyol esters alkoxylated polyol esters and mixtures thereof a preferred emulsifier c~",~,~,i ,i"g a sugar ester especially an ester selected from sucrose oleates and p..'~llilal~:, and mixtures thereof. Highly preferred herein is a fatty acid ester blend based on a mixture of sorbitan or sorbitol fatty acid ester and sucrose fatty acid ester the fatty acid in each instance being preferably Cg-C24 more preferably C10-c2o. The preferred fatty acid ester emulsifier from the viewpoint of moisturisation is a blend of sorbitan or sorbitol C1 6-C20 fatty acid ester with sucrose C1o-cl6 fatty acid ester especially sorbitan stearate and sucrose cocoate. This is co~ e~ 'y available from ICI under the trade name Arlatone 2121. The stA~ ",~clla~ ", of formulation derived from Arlatone 2121 is based on the formation of distinct liquid crystalline structures in the water phase into which the oil phase is W0 95/28913 2 ~ 8 ~ 8 7 ~ P~ s l 1~ .
dispersed. In order to achieve optimum moisturisation, absorption and skin feel together with reduced ~ aas;lless it is desirable for the ratio of primary oil to fatty acid ester emulsifier to lie in the range from about 6:1 to about 1:1, preferably from about 4:1 to about 1:1.
A further essential ingredient of the co",posiLiol,s herein is urea which is present in a level of from about 0.1% to about 20%, preferably from about 0.5% to about 10% and more preferably from about 1% to about 5% by weight of cr.,llpo:~iLiol~.
In preferred e",L,od;"lellL~, the oil phase and organic alll~ ' material are premixed in water at a temperature above the Kraft Point of the organic a~ Jhi~ ilic material (but preferably below about 60C) to form a liquid crystal/oil in water dispersion prior to addition of the urea. The urea is found to be especially effective herein in c~ lalion with the amphiphilic emulsifier material for providing outstanding skin moisturisation and softening in the context of an oil-in-water skin care emulsion Go""~o:,iLion.
Moreover, it is surprisingly found that the urea is rendered more stable to hydrolytic de~ladaliollr thereby allowing an increase in col"~.~si~iondl pH.
A wide variety of optional i~y~ L~ such as non-occlusive moisturizers, humectants, gelling agents, neutralizing a~qents, perfumes, colouring agents and surfactants. can be added to the skin culllpo~ilions herein.
The co~"po~i~ions llerein can comprise a humectant. Suitable humectantsfor use herein include sorbitol, propylene glycol, butylene glycol, hexylene glycol, ethoxylated 31ucose derivatives, hexanetriol, glycerine, water-soluble polyslycerylmethacrylate lubricants and par~Ll,enols. A preferred humectant herein is glycerine ~so"~i",es known as glycerol or glycerin~. Chemically, glycerine is 1,2,3-1~rupa"~,iol and is a product of co"",l,:n e. One large source of the material is in the manufacture of soap. Also preferred for use herein is butylene 31ycol.
In the present cu",posiLions, the humectant is preferably present at a level of from about 0.1% to about 20%, more preferably from about 1% to about 10%, and especially from about 2% to about 5% by weight of co"" osiLioll.

Suitable polyglyceryl~ Lllacrylate lubricants for use in the compositions of this invention are available under the trademark Lubrajel (RTM) from Guardian Chemical Corporation, 230 Marcus Blvd., Hauppage, N.Y. 11787.
In general, Lubrajels can be described as hydrates or clathrates which are formed by the reaction of sodium glycerate with a methacrylic acid polymer.
Thereafter, the hydrate or clathrate is stabilized with a small amount of propylene ~qlycol, followed by controlled hydration of the resulting product.
Lubrajels are marketed in a numrJer of ~qrades of varying glycerate: polymer ratio and viscosity. Suitabl ~ Lubrr jels include Lubrajel TW, Lubrajel CG and Lubrajel MS, Lubrajel WA, Lubr2j~' DV and so-called Lubrajel Oil.
At least part (up to about 5% by weight of composition~ of the humectant can be incorpor~ted in ~he form of an admixture with a particulate lipophilic or hydrophobic carrier material. The carrier material and humectant can be added either to the aqueous or disperse phase.
This copolymer is particularly valuable for reducing shine and co"l,~" ,9 oil while helpin~q to provide effective moisturization benefits. The cross-linked hydrophobic polymer is pl~ bly in the form of a copolymer lattice with at least one active illU~d;~ ll dispersed uniformly throughout .,nd entrapped within the copolymer lattice. Alternatively, the h~roohobic polymer can take the form of a porous particle having a surface ~rea (N2,BET) in the range from about 50 to 500, preferably 10~ to 300m2.g-1 and having the active ingredient absorbed therein.
The cross-linked l~ jdlupho~ic polymer is preferably present in an amount of from about 0.1% to about 10% by weight and is preferably ill~.ul~ ltd in the external aqueous phase. The active ingredient can be one or more or a mixture of skin co"",a~i~;e oils, skin colll~Ja~iLlr- humectants, emollients, moisturizing agents and sunscreens. In one embodiment, the polymer material is in the form of a powder, the powder bein~q a combined system of particles. The system of powder particles forms a lattice which includes unit particles of less than about one micron in average diameter, agul~ e~c,L~ of fused unit particles of sized in the range of about 20 W095128913 2 1 88~7 P~
to 100 microns in 2~/erage diameter and aggregates of clusters of fused ag~lo,,,t ,c~, of sizes in the range of about 200 to 1,200 microns in average diameter.
The powder material of this embodiment can be broadly described as a cross-linked "post absorbed" hydrophobic polymer lattice. The powder ,u~er~cbly has entrapped and dispersed therein, an active which may be in the form of a solid, liquid or gas. The lattice is in particulate form and constitutes free flowing discrete solid particles when loaded with the active material. The lattice may contain a pr'dddL~:llllilled quantity of the active material. A suitable polymer has the structural formula:
CH3 ~ CH3 C=O C=O
O O
R' - R" - Y
o C=O

where the ratio of x to y is 80:20, R' is CH2CH2- and R" is -(CH2) 11 CH3 The hydluphoL~ic polymer is a highly crosslinked polymer, more particularly a highly cross-linked polymethacrylate copolymer. The material is manufactured by the Dow Corning Co,~.orcLioll~ Midland.
Michigan, USA, and sold under the lldd~dlllalh POLYTRAP (RTM~. It is an ultralight free-flowing white powder and the particles are capable of absorbing high levels of lipophilic liquids and some hydrophilic liquids while at the same time IlldillLaillill9 a free-flowing powder character. The powder structure consists of a lattice of unit particles 2~ ~877 Wo 95/28913 1 less than one micron that are fused into a3ylu,,,e,aL~ of 20 to 100 microns and the agglomerates are loosely clustered into macro-particles or aggregates of about 200 to about 1200 micron size. The polvmer powder is capable of containing as much as four times its weight of fluids, emulsions, dispersion or melted solids.
Adsorption of actives onto the polymer powder can be accoi"~ dd using a stainless steel mixing bowl and a spoon, wherein the active is added to the powder and the spoon is used to gently fold the active into the polymer powder. Low viscosity fluids may be adsorbed by addition of the fluids to a sealable vessel containing the polymer and then tumbling the materials until a consiaL~ y is achieved. More elaborate blending equipment such as ribbon or twin cone blenders can also be employed. The preferred active i,,y,edi~llL for use herein is ~qlycerine. Preferably, the weight ratio of humectant: carrier is from about 1:4 to about 3:1.
Also suitable as a highly cross-linked polymethacrylate copolymer is M u~ponges 5647. This takes the form of generally spherical particles of cross-linked hydrophobic polymer having a pore size of from about 0.01 to about 0.05,um and a surface area of 200-300m2/g. Again, it is preferably loaded with humectant in the levels described above.
The co""~osiLions of the invention can also contain a hydrophilic gelling agent at a level preferably from about 0.01% to about 10%, more preferably from about 0.02% to about 2%, and especially from about 0.02% to about 0.5%. The gelling agent ~l~rt:labl~ has a viscosity 11%
aqueous solution, 20C, Brookfield RVT) of at least about 4000 mPa.s, more preferably at least about 10,000 mPa.s and especially at least 50,000 mPa.s.
Suitable hydrophilic gelling agents can generally be described as water-soluble or colloidal!y water-soluble polymers, and include cellulose ethers (e.g. hydroxyethyl cellulose, methyl cellulose, hydroxypropylmethyl cellulose), polyvinylpyrrolidone, polyvinylalcohol, guar gum, hydroxypropyl guar gum and xanthan gum.

W0 95/28913 ~ ~ 8 8 8 7 7 . ~
Preferred hydrophilic gelling agents herein, however, are acrylic acidlethyl acrylate copolymers and the carboxyvinyl polymers sold by the B.F.
Goodrich Company under the trade mark of Carbopol resins. These resins consist essentially of a colloidally water-soluble polyalkenyl polyether crosslinked polymer of acrylic acid crosslinked with from 0.75% to 2.00%
of a crosslinking agent such as for example polyallyl sucrose or polyallyl pentaerythritol. Examples include Carbopol 934, Carbopol 940, Carbopol 950, Carbopol 954, Carbopol 980, Carbopol 951 and Carbopol 981.
Carbopol 934 is a water-soluble polymer of acrylic acid clossli"h~:d with about 1% of a polyallyl ether of sucrose having an average of about 5.8 allyl groups for each sucrose molecule. A most preferred polymer is Carbopol 951. Also suitable for use herein are hydluphobi~.~lly modified cross-linked polymers of acrylic acid having alll~Jhi~aLlli~ properties available under the Trade Name Carbopol 1382, Carbopol 1342 and Pemulen TR-1 (CTFA Desiy"a~io,l: Acrylates/10-30 Alkyl Acrylate Crosspolymer). A
colllbilla~ioll of the polyalkenyl polyether cross-linked acrylic acid polymer and the hydrophobically modified cross-linked acrylic acid polymer is also suitable and is preferred for use herein. The gelling agents herein are particularly valuable for providing excellent stability cl~a,a~ ,i .Li..s over both normal and elevater~ temperatures.
Neutralizing agents suitable for use in neutralizing acidic group colllaill;llg hydrophilic gelling agents herein include sodium hydroxide, potassium hydroxide, ammonium hydroxide, monoell,a,~ola",i"e, ' lanolalllille and ll ie:ll lal lulal l lil le .
The co",posi~io,~s of the invention are in emulsion form and are preferably formulated so as to have a product viscosity of at least about 4,000 mPa.s and preferably in the range from about 4,000 to about 300,000 mPa.s, more preferably from about 8,000 to about 200,000 mPa.s and especially from about 10,000 to about 50,000 mPa.s ~25C, neat, Brookfield RVT
Spindle No. 5).
The compositions of the invention can also contain from about 0.1% to about 10%, preferably from about 1% to about 5% of a panthenol moisturizer. The panthenol moisturizer can be selected from D-panthenol (lRI-2,4-dihydroxy-N-[3-hydroxypropyl)]-3,3-dimethylbutamide), DL-~ WO95/28913 2 88877 r~
panthenol, calcium pantothenate, royal jelly, panthetine, pa"~u~ ;"e,panthenyl ethyl ether, pangamic acid, pyridoxin, pantoyl lactose and Vitamin B complex. Highly preferred from the viewpoint of skin care and tack reduction is D-panthenol.
The compositions of the present invention can additionally comprise from about 0.001% to about 0.5%, preferably from about 0.002% to about 0.05%, more preferably from about 0.005% to about 0.02% by weight of carboxymethylchitin. Chitin is a polysacLl,aride which is present in the integument of lobsters and crabs and is a mucopolysaccl1a,ide having beta (1-4) linkages of N-acetyl-D-glucosamine. Carboxymethylchitin is prepared by treating the purified chitin material with alkali followed by mono~lllolac~ic acid. It is sold col"",e,..;~'!y in the form of a dilute lapplu~illldL~ly 0.1% to 0.5% by weight) aqueous solution under the name Chitin Liquid available from A & E Connock Ltd., Fordingbridge, England.
Other optional materials include keratolytic agents such as salicylic acid;
proteins and polypeptides and derivatives thereof; water-soluble or sol~ ~ " ''e preservatives such as Germall 115, methyl, ethyl, propyl and butyl esters of hydroxybenzoic acid, benzyl alcohol, EDTA, Euxyl (RTM) K400, Bromopol (2-bromo-2-niL~u~.,u~,a"e-1,3-diol) and phenoxypropanol;
anti-bacterials such as Irgasan IRTM) and phenoxyethanol (preferably at levels of from 0.1% to about 5%); soluble or ~ ' 'lv soluble moisturising agents such as hylaronic acid and starch-grafted sodium polyacrylates such as Sanwet (RTM) IM-1000, IM-1500 and IM-2500 available from Celanese Su~ lal;so~Llelll Materials, Portsmith, VA, USA and described in USA-A-4,076,663; colouring agents; perfumes and perfume solubilizers and additional surfactants/emulsifiers such as fatty alcohol ethoxylates, ethoxyiated polyol fatty acid esters, wherein the polyol can be selected from glycerine, propyleneglycoi, ethyleneglycol, sorbitol, sorbitan, polypropyleneglycol, glucose and sucrose. Examples include glyceryl monohydroxy stearate and stearyl alcohol ethoxylated with an average of from 10 to 200 moles of ethyleneoxide per mole of alcohol and PEG-6 caprylic/capric glycerides.

wog~i/2sgl3 21 88~ 77 r~

Preferred enlbc ' .~e"L~ of the invention additionally comprise from about 0.1% to about 5% by weight of aluminium starch octenylsuccinate.
Aluminium starch octenylsuccinate is the aluminium salt of the reaction product of octenylsuccinic anhydride with starch and is C~ lCidlly available under the trade name from Dry Flo National Starch & Chemical Ltd.
Dry Flo is useful herein from the viewpoint of skin feel and ap~ ion r,l~al~.L~ lic.s.
Other optional materials herein in~lude pigments which, where water-insoluble, contribute to and are i~r,luded in the total level of oil phase di~nL~. Pigments suitable fol use in the compositions of the present invention can be organic and/or inorganic. Also included within the term pigment are materials having a low colour or lustre such as matte finishing agents, and also light scattering agents. Examples of suitable pigments are iron oxides, acyglutamate iron oxides, ultramarine blue, D&C dves, carmine, and mixtures thereof. Depending upon the type of composition, a mixture of pigments will normally be used. The preferred pigments for use herein from the viewpoint of moisturisation, skin fee~, skin a~Jpealdllce and emulsion c~"" " :"Ly are treated pigments. The pigments can be treated with compounds such as amino acids, silicones, lecithin and ester oils.
The pH of the cr ,i~posiLions is ~referably from about 4 to about 9, more preferably from about 5 o ~bout 7.5. The water content of the co",~.o:,iLio,~s herein is genrrally t-om about 30% to about 98.8%, preferably from about 50% to atout 95% and especially from about 60% to about 90% by weignt wo 95178913 2 ~ ~ 8 ~ ~ 7 r~"l The invention is illustrated by the following examples FY~rnDles I to V
1I 111 !Y Y
Cetyl Alcohol 0.25 0.3 0.2 0.3 0.25 Stearic Acid 0.11 0.2 0.1 0.2 0.1 Steareth 100 0.1 0.1 0.15 0.15 0.15 GMHS (1) 0.15 0.2 0.1 0.2 0.15 Cetyl Palmitate 3.0 2 3 4 2.5 Mineral Oil 2.0 3 4 3 3.5 Petrolatum 3.00 2 2.5 4 3.5 Wickenol 142 ~RTM) 0.60 1 1 1 0.7 Di",t:~l,ico,le 200 0.3 0.4 0.5 0.5 0 4 Propyl Paraben 0.08 0.08 0.07 0.08 0.07 Arlatone (RTM) 2121 6 4 7 5 4 Glycerin 3 8 3 2 7 Carbopol (RTM) 1342 0.095 0.075 0.075 0 075 0 075 Carbopol (RTM) 951 0.09 0.08 0.09 0.09 0.08 Na4 EDTA 0.1 0.2 0.1 0.1 0.1 Methyl Paraben 0.175 0.175 0.175 0.175 0.175 KOH0.3 0.2 0.2 0.2 0.2 D;",t:Ll,i~.one CL21403 3 - 4 3 Cr llic~ Gle~ - 2 Butylene Glycol - - - 2 DryFlo (RTM) - 1 - 0.5 Perfume 0.2 0.2 - 0.2 Urea 2.5 1.5 3 2 2.5 Colour 0.0004 0.0002 0.0003 1. Glycerylmonohydroxystearate The co"".G ,;Lions are made as follows:
A first premix of thickening agents Arlatone 2121 and other water soluble ingredients apart from urea is prepared by admixing in water and heating to about 80C. A second premix of oil phase i"~,~die,~L~
other than silicone gum is prepared by mixing and heating and is added to the aqueous premix.
The resulting mixture is cooled to about 60C. The silicone gum and urea are then added to the resulting oil-in-water emulsion and the mixture is cooled before adding minor i,,u,t:die,~L~. The CO~ o .ilion is ready for packaui~g~

wo 9SI28913 2 1 8 8 8 7 7 F~

The co",puaiLiuns dispiay improved moiâturisation, skin feel and skin care c1~a,a-,L~riaLi-,s together with reduced ~reasiness snd excellent rub-in and abso~i Liun cl~ald~Lt:lialics~

~ wogsn89l3 218~8~7 P~ m ExamDles Vl to X
VlVll Vlll IX 25 Cetyl A~lcohol 0.25 0.3 0.2 0.3 0.25 Stearic Acid 0.11 0.2 0.1 0.2 0.1 Steareth 100 0.1 0.1 0.15 0.15 0.15 GMHS ~1) 0.15 0.2 0.1 0.2 0.15 Cetyl Palmitate 3.0 2 3 4 2.5 Mineral Oil 2.0 3 4 3 3.5 Petrolatum 3.00 2 2.5 4 3.5 Wickenol 142 (RTM) 0.60 1 1 1 0.7 Dimethicone 200 0.3 0.4 0.5 0.5 0.4 Propyl Paraben 0.08 0.08 0.07 0.08 0.07 Arlatone (RTM) 2121 6 4 7 5 4 Glycerin 6 3 1.5 2 8 Carbopol (RTM) 1342 0.095 0.075 0.075 0.075 0 075 Carbopol (RTM) 954 0.09 0.08 0.09 0.09 0.08 Na4EDTA 0.1 0.2 0.1 0.1 0.1 Methyl Paraben 0.175 0.175 0.175 0.175 0.175 KOH0.3 0.2 0.2 0.2 0.2 Di",~Ll,icone Q21403 3 - 4 3 C~clo",~ll,i. one/
li"~ o~le copolyol 1.0 1.0 - 1.0 1;0 M u:lpoll~es 5647 - - 3.0 Lecithin - 0.1 Phenoxyethanol 0.2 0.2 0.2 0.2 0.2 Cr~ ,ui~ lOl~a~e: - 2 - 1 -Butylene Glycol - - - 2 DryFlo (RTM) - 1 - 0.5 Perfume 0.2 0.2 - 0.2 Urea 3 2.5 2 1.5 2 Colour 0.0004 0.0002 0.0003 1. Glycerylmonohydroxystearate The co"~uo~iLions of Examples Vl to X are made in the same way as the co""~G~iLiuns of Examples l-V above.

Claims

WHAT IS CLAIMED IS:

1. A skin care composition in the form of an oil-in-water emulsion comprising:
(a) from about 1% to about 60% by weight of oil;
(b) from about 30% to about 98.8% by weight of water;
(c) from about 0.1% to about 20% by weight of urea: and (d) from about 0.1% to about 20% by weight of an organic liquid crystal-forming amphiphilic emulsifier material.

2. A skin care composition according to Claim 1 wherein the oil and organic amphiphilic emulsifier material are premixed in water to form a liquid crystal/oil in water dispersion prior to addition of the urea.

3. A skin care composition according to Claim 1 or 2 wherein the urea is present in an amount in the range from about 0.5% to about 10%, preferably from about 1% to about 5% by weight.

4. A skin care composition according to any of Claims 1 to 3 wherein the amphiphilic emulsifier material is selected from polyol esters, alkoxylated polyol esters and mixtures thereof.

5. A skin care composition according to Claim 4 wherein the organic amphiphilic emulsifier material comprises a sugar ester, specially an ester selected from sucrose oleates and palmitates, and mixtures thereof.

6. A skin care composition according to Claim 5 wherein the emulsifier is a blend of sorbitan stearate and sucrose cocoate.

7. A skin care composition according to any of Claims 1 to 6 comprising from about 2% to about 30%, preferably from about 3% to about 20% by weight of oil and from about 2% to about 10% preferably from about 3% to about 7% of amphiphilc emulsifier material.

8. A skin care composition according to any of Claims 1 to 7 comprising one or more distinct oil phases and wherein the primary oil phase is essentially silicone-free and is present in a level of from about 4% to about 16% by weight and wherein the weight ratio of primary oil phase to emusifier is in the range from about 6:1 to about 1:1, preferably from about 4:1 to about 1:1.

9. A skin care composition according to Claim 8 wherein the primary oil phase comprises a natural or synthetic oil selected from mineral, vegetable, and animal oils, fats and waxes, fatty acid esters, fatty alcohols fatty acids and mixtures thereof.

10. A skin care composition according to any of Claims 1 to 9 incorporating a secondary oil phase which comprises a silicone or mixture of silicones in a level of from 0.1% to 20% by weight, preferably from about 0.5% to about 15%, more preferably from 1% to about 10% by weight of composition, and wherein the silicone or silicone mixture comprises a silicone gum having a molecular weight of from about 200,000 to about 4,000,000.

11. A skin care composition according to any of Claims 1 to 10 additionally comprising from about 0.1% to 10% of an optionally hydroxy substituted C8-C50 unsaturated fatty acid or an ester thereof.

12. A skin care composition according to Claim 11 wherein the optionally hydroxy substituted C8-C50 unsaturated fatty acid or ester thereof is cetyl ricinoleate.

13. A skin care composition according to any of Claims 1 to 12 additionally comprising from about 0.1% to about 20% by weight of a humectant selected from glycerine, polyglycerylmethacrylate lubricants, butylene glycol, sorbitol, panthenols, propylene glycol, hexylene glycol, ethoxylated glucose derivatives, hexanetriol and glucose ethers, and mixtures thereof.

14. A skin care composition according to Claim 13 wherein the humectant is selected from glycerine and butylene glycol, and mixtures thereof.

15. A skin care composition according to any of Claims 1 to 14 additionally comprising from about 0.01% to about 10% by weight of a hydrophilic gelling agent selected from carboxyvinyl polymers, preferably colloidally water-soluble polymers of acrylic acid cross-linked with from about 0.75% to about 2% of a cross-linked agent selected from polyalkyl sucrose and polyalkyl pentaerythritol.

16. A skin care composition according to any of Claims 1 to 15 wherein the gelling agent comprises a hydrophobically-modified cross-linked polymer of acrylic acid having amphipathic properties.

17. A skin care composition according to any of Claims 1 to 16 additionally comprising from about 0.1% to about 5% by weight of aluminium starch octenylsuccinate.