Abstract:
Oil mixtures, which provide lipid compositions for restraining skin degeneration, contain, by weight, 30% to 50% rice bran oil and 15% to 25% sesame oil and also contain additional oil, which includes in particular, oil from among maize oil, wheat germ oil and sunflower oil, so that the composition contains linoleic acid and contains vitamin E for protecting the composition against oxidation, the composition being prepared from oils containing gum, color and odor which are subjected to degumming, decoloring and deodorizing, the deodorizing being carried out under conditions of temperature and vacuum so that the composition has at least 2% by weight unsaponifiable oil matter and particularly from 2% to 3% unsaponifiable oil matter.

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns a lipid composition intended to be used in cosmetic compositions, in particular a lipid composition having an anti-ageing action. 
     Premature ageing of the epidermis is partly due to external attack such as for example from UV radiation and pollution generating free radicals. 
     It is known, for example from European Patent Application Publication No. 0477825, that sesame oil has the property of stabilizing edible vegetable oils rich in unsaturated fatty acids, for example maize oil, against oxidation. 
     The anti-radical properties of unsaponifiable fractions of sesame oil and wheat germ oil in cosmetic compositions are also known, for example from European Patent Application Publication No. 0581624. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a lipid composition for cosmetic products having an anti-ageing action on the skin, namely an anti-radical, soothing and hydrating action, while being naturally stabilized against oxidation, namely not containing added anti-oxidants. 
     To that end, lipid compositions of the present invention for cosmetic products or for cosmetic purpose are based upon a mixture of oils which provide anti-ageing action, maintain good hydration at the epidermis and have anti-radical properties, and the oils employed are rich in antioxidant unsaponifiable compounds. 
     The invention also provides processes for preparation of the lipid compositions, in which raw or partially refined oils are used, characterized in that the mixture of oils is degummed, decolorized and deodorized, wherein the deodorization is carried out under conditions enabling obtaining a content of at least 2% by weight, and in particular, a content 2% to 3% by weight, of unsaponifiable matter, as well as stability against oxidation corresponding to an induction period of at least 15 h in the RANCIMAT test at 100° C. 
     The lipid composition according to the invention is characterized in that it comprises a mixture of oils which comprise, in particular, rice bran oil and sesame oil and in that it comprises at least 2% by weight unsaponifiable matter, and in particular, from 2% to 3% by weight of unsaponifiable matter, and in that the fatty acids of the triglycerides comprise, by weight, 30% to 40% of oleic acid, 40% to 50% of linoleic acid and less than 2% of alpha-linolenic acid. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The composition of the present invention contains rice bran oil which is particularly rich in gamma-oryzanol which has anti-oxidant activity. 
     The composition also contains sesame oil, certain constituents of which specifically inhibit delta 5 desaturase, the enzyme responsible for the biotransformation of dihomogamma-linolenic acid (DHGLA) into arachidonic acid (AA). It is thus likely to have an anti-inflammatory action, in as much as the formation of products derived from AA, such as, for example, leucotriene B4, which is pro-inflammatory, should profitably reduce products derived from DHGLA, for example prostaglandins of series 1 having an anti-inflammatory action. 
     The composition contains an oil comprising an appreciable quantity of oleic acid which has a structuring action and acts as a vehicle for essential bio-active fatty acids while being neutral from the point of view of bioactivity. The oleic acid content gives the lipid mixture good stability to oxidation and photo-oxidation, which prevents the formation of active oxygenated radicals. 
     The oils of choice meeting these requirements are preferably rice bran oil and sesame oil. The oils in question preferably constitute 45% to 65%, for example 60%, by weight of the final lipid mixture. 
     The composition contains oils providing essential fatty acids of the n-6 family, low n-3 fatty acids, so as to take account of the greater biochemical reactivity of those of the n-3 family. 
     Oils rich in fatty acids of the n-6 family are selected from those rich in linoleic acid, for example maize oil, wheat germ oil, sunflower oil or blackcurrant seed oil. Thus the composition has a high linoleic acid content, with 40% to 50% by weight of fatty acids. This acid is a constituent of ceramides which play an important role as a barrier against dehydration of the epidermis. Linoleic acid also shows itself to be active against cellular hyperproliferation associated with lack of essential fatty acids, an effect that could be associated with the re-establishment of normal levels of series 2 prostaglandins in the epidermis. 
     These &#34;active&#34; fatty acids can also be incorporated in the formulation in the form of their ethyl or propionic esters, in quantities calculated so as to obtain the desired relative levels and proportions. 
     The composition according to the invention also contains an oil rich in vitamin E which can improve its keeping properties, for example a wheat germ oil. 
     The average composition in fatty acids of the triglycerides in the final composition is as follows: 
     
         ______________________________________Fatty acids % by weight          % by weight______________________________________C16:0       10-15       preferably                            &lt;13.5C16:1,n-7   0.05-0.5    &#34;        &lt;0.3C18:0       1-4         &#34;        &lt;3C18:1,n-9   30-50       &#34;        &lt;35C18:2,n-6   40-60       &#34;        &lt;48C18:3,n-3 (alpha)       1-2         &#34;        &lt;2C20:0       &lt;1          &#34;        &lt;0.5C20:1       &lt;1          &#34;        &lt;0.5______________________________________ 
    
     On the basis of their respective compositions in fatty acids and in natural anti-oxidant constituents, the following mixtures of oils are preferred: 
     
         ______________________________________Oil        % by weight          % by weight______________________________________Rice bran oil      30-40       preferably                           40Maize oil  20-40       &#34;        30Sesame oil 15-25       &#34;        20Wheat germ oil       5-15       &#34;        10______________________________________ 
    
     According to the processes of the present invention, a cold-pressed sesame oil is preferably used, which contains the desired compounds sesamoline and sesamine. Wheat germ and sesame oils are preferably chosen that are low in lecithins and rich in unsaponifiable matter. 
     Degumming preferably takes place by putting the mixture of oils in contact with a concentrated solution of citric acid, in the presence of water at about 80° C., during which hydration is carried out, followed by separation of the gums, for example by centrifuging or decanting. 
     In a variant of the degumming treatment, the mixture of oils heated to 80° C. is treated by circulating steam under vacuum. 
     After separation of the gums, as indicated previously, the mixture of degummed oils is treated by putting it into contact with an adsorbent consisting of damp amorphous silica gel for about 20 min at 80°-85° C. under a vacuum of about 50-80 mbar. 
     In certain cases, bleaching is also carried out with decolorizing earth activated with acid. 
     Finally, the mixture of oils is deodorized under controlled conditions, for example at about 180° C. with about 1% live steam and under a vacuum of about 1-2 mbar for about 2 h. It is thus possible to maintain an appreciable content of unsaponifiable matter and in particular to control the tocopherols. 
     The lipid composition according to the invention may be advantageously used in various aqueous or anhydrous cosmetic compositions for treatment of the skin, such as fluids, creams and lotions for the face, hands and body, sun creams and lotions, antiwrinkle creams and lotions and similar compositions. 
     The cosmetic composition in question can be, in particular, in the form of a solution, a water-in-oil emulsion or an oil-in-water emulsion, a suspension or an aerosol. As anhydrous cosmetic compositions incorporating the lipid composition according to the invention, reference may be made to body oils, anhydrous balms, anti-sun oils and lipsticks. 
     In such a cosmetic composition, the lipid composition according to the invention may represent 1 to 80%, preferably 5 to 60% by weight. 
     Such a cosmetic composition generally includes, in suitable quantities, additives such as, for example emulsifiers, anti-perspirant agents, stabilizers, preservatives, sun filters, perfumes, dyes or emollients, waxes, pearl agents and inorganic or organic fillers. 
     The lipid composition according to the invention may also be used for a cosmetic purpose in the form of a nutritional supplement, for example in capsules or gelatin capsules. 
    
    
     EXAMPLES 
     The following examples illustrate the invention. In these, percentages and parts are given by weight except where indicated to the contrary. 
     Examples 1-3 
     Preparation of the mixture of oils 
     The following partially refined oils were mixed with stirring and under nitrogen in the proportions indicated. 
     
         ______________________________________  Oil      %______________________________________  Rice bran oil           40  Maize oil           30  Sesame oil           20  Wheat germ oil           10______________________________________ 
    
     In order to do this, the oils were mixed in the proportions indicated above in a stainless steel reactor provided with a double walled system with fluid circulation to keep the temperature constant and a variable speed stirrer, avoiding temperatures greater than 30° C. 
     Example 1 
     The mixture was then heated to 65° C. and treated with 0.3% of 50% citric acid, 2 to 3% water was added and the precipitated gums were separated off by centrifuging. 
     The degummed mixture was then put into contact with 1% hydrated amorphous silica gel (TRISYL) and 0.5% hydrated amorphous silica gel (TRISYL 300) at 80°-85° C. for 20 min under a vacuum of 50-80 mbar. 
     The mixture was finally deodorized at 180° C. for 3 hours by steam entrainment with 1% of steam per hour. 
     The properties of the final mixture of refined oils were as follows: 
     
         ______________________________________LOVIBOND colour, 2.5 cm (1&#34;) cell, R                   0.9LOVIBOND colour, 2.5 cm (1&#34;) cell, Y                   5.3Induction time, RANCIMAT test, h                   17.5Unsaponifiable matter content, measured by                   21.3IUPAC method 2.104, g/kgFree fatty acid content, %                   0.28______________________________________ 
    
     Example 2 
     The procedure was as in the preceding Example 1, apart from the fact that the preliminary degumming was carried out by steam treatment at 80° C. for 20 min with 2% steam. The results of the LOVIBOND colour analyses and the RANCIMAT test were identical. 
     Example 3 
     The procedure was as in Example 2, except that the degummed mixture was put into contact with 0.5% of TRISYL 300 hydrated amorphous silica gel and that following this treatment the mixture was put in contact with 0.25% of TONSIL OPTIMUM FF decolorizing earth before deodorization. The coloration and the induction time results were as follows: 
     
         ______________________________________LOVIBOND colour, 2.5 cm (1&#34;) cell, R                  1.4LOVIBOND colour, 2.5 cm (1&#34;) cell, Y                  9.5Induction time, RANCIMAT test, h                  16.5______________________________________ 
    
     Example 4 
     
         ______________________________________Anhydrous balmIngredients             %______________________________________Lanolin                 35Hydrogenated lanolin    30Ozokerite               3Lipid composition according to Example 2                   20Cyclopentadimethylsiloxane                   12______________________________________ 
    
     The anhydrous product of this Example was obtained by mixing the constituents at 70° C., and then cooling with stirring until room temperature was reached. 
     Example 5 
     
         ______________________________________Ingredients         %______________________________________Fatty alcohol esters C.sub.8 -C.sub.10               26Ozokerite           10Carnauba wax        3Bees wax            3Pigment             9Perfume             0.1Castor oil          qsp 100Lipid composition of Example 2               6______________________________________ 
    
     The pigments were sieved. The constituents were then mixed at 70° C., except for the perfume. The mixture was left to cool to 35° C. with stirring and the perfume was then added. The preparation was finally transferred to a triple roll mill. 
     Example 6 
     
         ______________________________________Make-up foundationIngredients           %______________________________________Lipid composition of Example 2                 4Mixture of glyceryl mono-di-stearate,                 3.3stearic acid and glycerine (40/50/5/5)Mixture of lanolin alcohol and                 3liquid paraffin (15/85)Glyceryl mono-di-iso-stearate                 1.8Isopropyl palmitate   5ethyl-2-hexyl palmitate                 5Titanium oxide        8.31Brown iron oxide      0.73Yellow iron oxide     1.7Black iron oxide      0.26Propyl p-hydroxybenzoate                 0.1Methyl p-hydroxybenzoate                 0.1Perfume               0.3Triethanolamine       1.2Hydrated magnesium aluminium silicate                 1.5Sodium carboxymethylcellulose                 0.14Cyclopentadimethylsiloxane                 8Glycerine             3Sterilized demineralized water                 qsp 100Propylene glycol      3Stearic acid          2.4______________________________________ 
    
     The pigments were blended and sieved and they were then incorporated in the oily phase, previously warmed to 70° C. The sodium carboxymethylcellulose was dispersed separately in water. When the solution was homogeneous, the other components of the aqueous phase were added and the mixture was heated to 75° C. The two phases were then emulsified with rapid homogenization. The emulsion was then allowed to cool with stirring, the perfume and triethanolamine were added at 35° C. and homogenization was then carried out. The preparation was then transferred to a triple roll mill. 
     Example 7 
     
         ______________________________________Moisturising protective body lotionIngredients           %______________________________________Polysorbate 60        0.8Perfume               0.3Glycerol stearate and PEG 100 stearate                 1Hydrogenated polyisobutene                 2Lipid composition of Example 2                 8Stearic acid          1Glycerine             3CARBOPOL 941          0.3Triethanolamine       0.3Water + preservative  qsp 100______________________________________ 
    
     The CARBOPOL 941 was dispersed in water. When the solution was homogeneous, the other components of the aqueous phase were added and the mixture was heated to 75° C. The constituents of the oily phase were mixed separately at 70° C. The two phases were then emulsified with rapid homogenization. The mixture was allowed to cool with stirring and the perfume, triethanolamine and preservative were added at 35° C., followed by homogenization. The preparation was allowed to cool to room temperature and packaged. 
     Example 8 
     
         ______________________________________Protective care fluidIngredients             %______________________________________Methyl glucose sesquistearate                   2Lipid composition of Example 2                   2Cyclomethicone          13Perfume                 0.2PEG 20 methyl glucose sesquistearate                   2Xanthan gum             0.2Polyacrylamide acid and C.sub.13 -C.sub.14 -isoparaffin                   0.8and laureth 7Water + preservatives   qsp 100______________________________________ 
    
     The xanthan gum was dispersed in water at 75° C. The constituents of the oily phase were mixed separately at 70° C. The two phases were then emulsified under rapid homogenization. The mixture was allowed to cool with stirring, the perfume and preservative was added at 35° C. and homogenization was then carried out. The preparation was then allowed to cool to room temperature and packaged. 
     Example 9 
     
         ______________________________________Protective care cream, oil-in-water emulsionIngredients             %______________________________________PEG 20 stearate         1Glyceryl stearate and PEG 100 Stearate                   1Stearic acid            1Stearyl alcohol         2Lipid composition of Example 2                   20Soya protein hydrolysate                   0.2Glycerine               3CARBOPOL 941            0.4Triethanolamine         0.4Water + preservative    qsp 100______________________________________ 
    
     The CARBOPOL 941 was dispersed in water. When the solution was homogeneous, the other components of the aqueous phase were added and the mixture was heated to 70° C. The constituents of the oily phase were mixed separately at 75° C. Emulsification of the two phases was then carried out under rapid homogenization. The mixture was then allowed to cool with stirring and the perfume was added at 35° C., followed by homogenization. The preparation was allowed to cool to room temperature and packaged. 
     Example 10 
     
         ______________________________________Care cream, water-in-oil emulsionIngredients             %______________________________________Sorbitan monoisostearate                   5Microcrystalline wax    1Lipid composition of Example 2                   19Fatty acid esters in C.sub.8 -C.sub.10 and                   1fatty alcohol esters in C.sub.12 -C.sub.18Modified Montmorillonite gel and neutral oil                   5(triglycerides of caprylic and capric acids)Propylene glycol        3Water + preservative    qsp 100______________________________________ 
    
     The constituents of the oily phase were mixed at 75° C. The constituents of the aqueous phase were mixed separately at 70° C. After emulsification of the two phases with rapid homogenization, the mixture was allowed to cool with stirring to room temperature and packaged.