IES980410A2 - A cosmetic composition - Google Patents

Abstract

A cosmetic composition comprising: (a) squalane derived from a plant source in an amount in the range of 0.1% to 7.5% of the total weight of the composition; (b) a mixed triester which results from the reaction of glycerin and caprylic and capric acids in an amount in the range of 0.1% to 15% of the total weight of the composition; (c) a natural fatty acid glyceride that is obtained from the nuts of the karite or shea butter tree (Butyrospermum Parkii) in an amount in the range of 0.1% to 10% of the total weight of the composition; (d) a bridged malonamide having a molecular weight of greater than 450 in an amount in the range of 0.05% to 2.75% of the total weight of the composition; and (e) a cosmetically acceptable carrier, provided that the combined amounts of ingredients (a) to (d) does not exceed 17% by weight of the total composition. The composition mimics certain aspects of the epidermal lipids of the skin thus helping to retain the moisture retaining properties of the skin.

Description

The present invention relates to a cosmetic composition, in particular a skincare composition.

Background of the Invention: Cosmetics are used to enhance a person’s beauty either by cleansing, colouring moisturising Cosmetic skincare products have been used to prevent premature ageing and dryness by moisturising the skin and protecting it from environmental elements which tend to cause skin damage. In particular facial skincare products are important as the face tends to be exposed to the elements more frequently than the skin of other parts of the body.

LODGED The skin is composed of different layers. From a cosmetic point of view it is the outer layer, the epidermis, which is of most importance. The external protective layer of the epidermis is the stratum comeum. The stratum corneum is composed of cells called corneocytes embedded in an extracellular matrix of multiple lipid bilayers. The entire stratum corneum forms a water barrier, thus controlling moisture loss from the skin.

Its proper function is essential for maintaining beautiful and healthy skin.

A healthy skin is dependent on the correct balance of lipids, hygroscopic watersoluble substances and water, with intercellular lipids playing a role in the water holding properties.

Two important functions of the stratum comeum are retention of moisture and prevention of water loss. Many factors such as exposure to environmental conditions like low humidity, insufficient hydration from epidermal layers and air movements may contribute to excessive water loss from the stratum comeum and as a result cause the skin to become dry. Continuous and prolonged immersion in soap or detergent solutions may also contribute to dryness of the stratum corneum.

One of the characteristics of aged skin is a partial decrease in the hygroscopic water soluble components, resulting in a lowered capacity for binding water in the stratum comeum and hence a dry skin. The cause of dry skin is the removal of skin surface lipids, the stratum comeum lipids and the dissolution of the hygroscopic water soluble components of the stratum corneum.

Emollient creams and lotions, which contain moisture binding ingredients and/or lipids and/or oils which contribute to improving the barrier function of the skin have a positive effect on skin hydration and have thus been used as skincare products. These products help to improve the appearance of skin and reduce the impact of irritants on the skin.

Skincare compositions are described by Rawlings et al in PCT publication no. WO 94/10131 employing phytosphingosine - containing ceramide one structures. These OPEN TO PUBLIC WSPEC UNDER SECTION 28 AND RULE 2 compositions are described as having a positive effect on the water barrier function of the skin and reducing water loss. skinj WO 94/07844 discloses hydroxyl alkyl amides of dicarboxylic acids and their use in cosmetic compositions. The hydroxyl alkyl amides disclosed are pseudoceramides DMS® a product commercially available from Rhone Poulenc Rorer contains a phospholipid, lipids such as shea butter (which contains phytosterols) and squalane (obtained from olive oil) and caprylic/capric triglyceride Object of the Invention.

It is an object of the present invention to provide alternative cosmetic compositions which act to reduce moisture loss from the skin and which help to maintain a healthy skin.

Summary of the Invention: The present invention provides a cosmetic composition comprising: (a) squalane derived from a plant source in an amount in the range of 0.1% to 7.5% of the total weight of the composition; (b) a mixed triester which results from the reaction of glycerin and caprylic and capric acids in an amount in the range of 0.1% to 15% of the total weight of the composition; (c) a natural fatty acid glyceride that is obtained from the nuts of the karite or shea butter tree (Butyrospermum Parkii) in an amount in the range of 0.1% to 10% of the total weight of the composition; (d) a bridged malonamide having a molecular weight of greater than 450 in an amount in the range of 0.05% to 2 75% of the total weight of the composition; and (e) a dermatologically acceptable carrier provided that the combined amounts of ingredients (a) to (d) does not exceed 17% by weight of the total composition Beyond the limit of 17% stability problems could occur in the composition It is believed that the compositions of the present invention mimic certain aspects of the epidermal lipids of the skin thus helping to maintain the moisture retention properties of the skin.

In one embodiment of the present invention the composition further comprises a solvent which may be in addition to or comprised in the carrier (e). Suitably the solvent is selected from the group consisting of glycerin, sorbitol, propylene glycol, butylene glycol and/or other polyhydric alcohols, their esters and ethers. These solvents may also function as humectants.

Detailed Description of the Invention: IE 980410 The cosmetic compositions of the invention are for application to human skin, more particularly the stratum corneum where they improve moisturisation. The compositions help to restore the moisture barrier function of the skin. The compositions of the invention are particularly useful for application to the face.

The compositions of the invention can be used in combination with one or more of the following additional ingredients; (i) humectants such as glycerin, sorbitol, propylene glycol, butylene glycol, and lactylates; (ii) emollients such as cetyl alcohol, stearyl alcohol, myristyl alcohol, oleic alcohol, stearic acid, lauric acid, coconut oil, avocado oil, olive oil, castor oil, cholesterol, rapeseed oil, palmitic acid, cycfomethicone, dimethicone, dioctyl adipate, hexyldecanol, octyldecanol, glyceryl monostearate, polyisobutene, polyisoprene, lanolin, polybutene and myristyl myristate; (iii) skin-conditioner agents such as hydrogenated polydecane, hydrogenated isobutene, hydrogenated palm glycerides, hydrogenated olive oil, hydrogenated jojoba oil, coconut fatty acid triglyceride, refined phytosterols derived from edible soya oil; (iv) complex lipids in which one of the primary hydroxyl groups of glycerin is esterified with a phosphoric acid which carries an additional ester grouping and the other two remaining hydroxyl groups are esterified with long chain, saturated or unsaturated fatty acids.

Squalane derived from a plant source refers to squalane such as that obtainable from the unsaponifiable fraction of olive oil. The mixed triester which results from the reaction of glycerin and caprylic and capric acids generally contains caprylic acid at 50-65% and capric acid at 30-45%.

The natural fatty acid glyceride that is obtained from the nuts of the karite or shea butter tree (Butyrospermum Parkii, Bassio Parkii) is also known as shea butter Humectants are normally hygroscopic materials.

Experimental Details The beneficial effects of the compositions of the invention can be demonstrated by carrying out Comeometer CM 825 moisturisation studies which are used to evaluate moisture retention properties of the skin due to the compositions of the invention being applied to the human skin. The moisture retention properties shown on treated areas are good and show improvement over control areas which were untreated.

Moisturisation Study Protocol IE 980410 This study demonstrates the improved moisture retention in the skin due to the compositions of the invention when applied to the skin as compared to untreated areas of skin which were used as a control. A Corneometer CM825 (Courage & Khazaka) was used to measure the water content variation in the stratum corneum. This instrument takes measurements of the capacitance of the stratum corneum. The dielectric constant of water is relatively high and will effect the capacitance of a capacitor. Different dielectric constant due to different skin moisture levels can thus be measured The instrument has a probe containing the precision capacitor attached to a liquid crystal display and can be connected to a computer. An active special purpose glass face of the probe is applied to the relevant skin area e g. volar forearm. A measurement of capacitance is taken and the value displayed on the liquid crystal display is the relative degree of moisture content of the stratum corneum of the skin. The contact pressure applied by the active probe is maintained at a constant level by means of a special design feature on the probe.

Example 1 A cosmetic composition in the form of a skincare lotion was prepared using the following raw materials which are identified by INCI name. (INCI is an abbreviation for the International Nomenclature Cosmetic Ingredient. INCI nomenclature is internationally accepted and is detailed in publications such as International Cosmetic Ingredient dictionary and handbook (7th edition 1997 published by: The Cosmetic Toiletry and Fragrance Association, 1101 17th Street, N W. Suite 300, Washington DC 20036-4702, United States of America). All ingredients are listed by their European Union (EU) INCI name with the exception of the ingredients: Water, Shea Butter and Fragrance which are listed by their US CTFA (Cosmetic Toiletry and Fragrance Association) name with the corresponding European Union INCI name listed alongside in parenthesis.

All data is given as the percentage weight/weight of the total composition.

INCI Name Phase A Water (Aqua) to 100 (“To 100” is used in this Example and the following Examples to indicate that water forms the remainder of the composition and does not include water of the other phases).

Carbomer 0.22 Butylene Glycol 2.00 Methylparaben 0.20 B Stearic Acid 1.40 Glyceryl Stearate SE 3.20 Caprylic/Capric Triglyceride 1.50 Squalane 3.00 Ceteareth-12 1.40 Shea Butter (Butyrospermum Parkii) 1.00 Bishydroxyethyl Biscetyl Malonamide 0.20 Propylparaben 0 10 Phase C Water 1.00 Triethanolamine 0.45 Phase D Water 1.00 Imidazolidinyl Urea 0.30 Phase E Fragrance (parfum) 0.30 IE 980410 Preparation: The Carbomer was dispersed and mixed into water which was heated to 75-8O°C and the remaining raw materials from phase A added The temperature of this phase was maintained at 75-80°C. The raw materials from phase B were mixed with heating to 75-80°C. Phase B was added to phase A with milling and stirring and then phase C was added. Milling and stirring were continued yntil a homogenous emulsion was formed. The emulsion was then stirred until cool and phases D and E were added.

The skincare lotion produced had a pH in the range 6-7.

Example 2 A cosmetic composition in the form of a skincare cream was made from the following raw materials: All data is given as the percentage weight/weight of the total composition.

INCI Name Phase A Water (aqua) to 100 Propylene Glycol '3.00 Carbomer 0 50 Methylparaben 0.25 Phase B Glyceryl Stearate, PEG -100 Stearate 3.50 Cetyl Alcohol 0.80 Stearic Acid 2.00 Squalane 4.00 Caprylic/Capric Triglyceride 3 .00 Shea Butter (Butyrospermum Park’d) 2.00 Bishydroxyethyl Biscetyl Malonamide 0.75 IE 980410 Phase C Water 2.00 Tetrahydroxypropyl Ethylenediamine 1.60 Phase D Water 1.00 Imidazolidinyl Urea 0.30 Phase E Fragrance (parfum) 0.30 A skincare cream was prepared by combining the ingredients as described in Example 1.

The skincare cream produced had a pH in the range 6-7.

Example 3 A cosmetic skincare cream was made using the following raw materials All data is given as the percentage weight/weight of the total composition INCI Name Phase A Water (aqua) to 100 Carbomer 0.50 Glycerine 2.00 Methylparaben 0.25 Phase B Petrolatum 1.00 Squalane 2.20 Caprylic/CapricTriglyceride 5.50 Glyceryl Stearate 1.75 Shea Butter (Butyrospermum Parkii) 1.40 Bishydroxyethyl Biscetyl Malonamide 1.00 Cetyl alcohol 0.80 Sorbitan Stearate 0.40 PEG- 40 Stearate 1.35 Propylparaben 0.15 Phase C Water 2.00 Tetrahydroxy propyl Ethylenediamine 1.25 Phase D Water 1.00 Imidazolidinyl Urea 0.30 Phase E Fragrance (parfum) 0.30 JBtSftQAiPe A skincare cream was prepared by combining the ingredients as d I, The skincare cream produced had a pH in the range 6-7.

Example 4 A skincare cream was prepared by combining the following ingredients as described in Example 1. All data is given as the percentage weight/weight of the total composition.

INCI Name Phase A Water to 100 Carbomer 0.50% Glycerine 1.00 Methylparaben 0.25 Phase B Glyceryl Stearate, PEG 100 Stearate 3.00 Cetyl Alcohol 1.00 Squalane 4.00 Caprylic/Capric Triglyceride 5.00 Shea Butter (Butyrospermum Parkii) 1.00 Bishydroxyethyl Biscetyl Malonamide 1.00 Stearic Acid 2.00 Propylparaben 0.15 Phase C Water 2.00 Tetrahydroxypropyl ethylenediamine 1.60 Phase D Water 1.00 Imidazolidinyl Urea 0.30 Phase E Fragrance (parfom) 0 30 The cream produced was a homogenous cream with a pH in the range 6-7.

Evaluation of the moisturising effect of a formulation of Example 4: The moisturising effect of the formulation of Example 4 was measured on the volar forearms of five volunteers using a Corneometer CM825 as described above. A measured quantity (approximately 0.040grams) of a formulation prepared according to Example 4 was applied to the volar forearms of five volunteers and spread in a manner to ensure coverage of the product over a defined area (treated area). The time was recorded when the product was applied and spread on the deflrlsi S8Q4slt0ie of application determined the time of assessing the treated area. The test sites on the volunteer volar forearms were systematically rotated throughout the panel i.e. alternating between being “near the elbow” and being “near the wrist” to ensure randomisation of results and prevent corruption of the results from location of the test site on the forearm. To avoid re-testing an area which was previously tested using the Corneometer CM825, which may have removed some of the formulation being examined, five subareas of the test site were created Each of the five subareas was measured using the Corneometer CM825 at different time intervals i.e. after 30mins, 60mins, 120mins, 300mins and 480mins Ten measurements were taken on the subareas at each time interval. Ten measurements were also taken on the untreated sites, which were located adjacent to the treated area, at each time interval. The results of this test is given in Table 1 below: The data given in Tablel demonstrates a positive effect on the moisture levels in the stratum corneum of the skin, to which the composition of Example 4 was applied. The benefit was observed over several time intervals.

Claims (10)

Claims: IE 980410

1. A cosmetic composition comprising: (a) squalane derived from a plant source in an amount in the range of 0.1% to 7.5% of the total weight of the composition; (b) a mixed triester which results from the reaction of glycerin and caprylic and capric acids in an amount in the range of 0.1% to 15% of the total weight of the composition; (c) a natural fatty acid glyceride that is obtained from the nuts of the karite or shea butter tree (Butyrospermum Parkii) in an amount in the range ofO. 1% to 10% of the total weight of the composition; (d) a bridged malonamide having a molecular weight of greater than 450 in an amount in the range of 0.05% to 2.75% of the total weight of the composition; and (e) a cosmetically acceptable carrier, provided that the combined amounts of ingredients (a) to (d) does not exceed 17% by weight of the total composition.

2. A cosmetic composition according claim 1 wherein squalane is present in an amount in the range of 1.0 to 5.25% of the total weight of the composition.

3. A cosmetic composition according to any preceding claim wherein the mixed triester is present in an amount in the range of 1.0 to 7.0% of the total weight of the composition

4. A cosmetic composition according to any preceding claim wherein natural fatty acid glyceride that is obtained from the nuts of the karite or shea butter tree (Butyrospermum Parkii) is present in an amount in the range of 0.5 to 4.0% of the total weight of the composition.

5. A cosmetic composition according to any preceding claim wherein the bridged malonamide is present in an amount in the range of 0.2 to 1.4% of the total weight of the composition.

6. A cosmetic composition according to any preceding claim wherein the bridged malonamide is bishydroxyethyl biscetyl malonamide

7. A cosmetic composition according to any preceding claim which further comprises a solvent.

8. A cosmetic composition according to claim 7 wherein the solvent is selected from the group consisting of glycerin, sorbitol, propylene glycol, butylene glycol and/or polyhydric alcohols, their esters and ethers Tomkins & Co. IE 980410 Abstract A Cosmetic Composition A cosmetic composition comprising: (a) squalane derived from a plant source in an amount in the range of 0.1% to 7.5% of the total weight of the composition; (b) a mixed triester which results from the reaction of glycerin and caprylic and capric

9. 10 acids in an amount in the range of 0.1% to 15% of the total weight of the composition; (c) a natural fatty acid glyceride that is obtained from the nuts of the karite or shea butter tree (Butyrospermum Parkii) in an amount in the range of 0.1% to 10% of the total weight of the composition; (d) a bridged malonamide having a molecular weight of greater than 450 in an amount in the range of 0.05%

10. 15 to 2.75% of the total weight of the composition; and (e) a cosmetically acceptable carrier, provided that the combined amounts of ingredients (a) to (d) does not exceed 17% by weight of the total composition. The composition mimics certain aspects of the epidermal lipids of the skin thus helping to retain the moisture retaining properties of the skin.