WO2002080882A1

WO2002080882A1 - Skin care cream containing omega-3

Info

Publication number: WO2002080882A1
Application number: PCT/NO2002/000104
Authority: WO
Inventors: Johan Myhre
Original assignee: Pronova Biocare As
Priority date: 2001-03-15
Filing date: 2002-03-13
Publication date: 2002-10-17
Also published as: NO313934B1; NO20011327D0; NO20011327L

Abstract

The present invention relates to a skin care preparation (skin cream) which contains omega-3 fatty acids that do not oxidise, even after application to the skin. The invention also relates to a method for preparing a skin cream of this kind.

Description

Skin care cream containing omega- 3

The present invention relates to a skin care preparation (skin cream) in the form of an emulsion, which contains, among other ingredients, unsaturated fatty acids that are prevented from oxidising, and also to a method for preparing a skin cream of this kind.

In Norway there is a long tradition of using cod liver oil as a dietary supplement, in particular because fish liver oil is considered to be a valuable source of vitamins. In more recent times, there has been a growing awareness of the important role of fish oils as a source of polyunsaturated fatty acids (Dyrberg et al., Lancet ii, 117- 1 19, 1978), and today fish oil is considered to be the best source of the so-called omega-3 fatty acids (omega-3 : fatty acids where the last double bond is three carbon atoms from the end of carbon chain). Research has shown that these fatty acids reduce the risk of cardiovascular disease and that they play an important role in the development of infants. It has long been known that fish liver oil has a healing effect on different types of skin disorders. Recent research has shown that it is the omega-3 fatty acids in the fish liver oil which contribute to this, although the mechanism(s) of action have not been charted. In the body the omega-3 fatty acids are used to perform functions such as forming membranes, and they are known to have a beneficial effect on the skin and also to be anti-inflammatory.

However, a problem associated with the use of omega-3 fatty acids in skin care preparations/creams has been that on oxidation they develop an unpreventable rancid fish oil smell, and therefore there have been very few attempts to use omega-3 fatty acids in this way. However, one patent application which has described the use of omega-3 fatty acids in a skin care preparation is NO 19980711, which relates to a skin care preparation that requires the presence of urea (carbamide). According to the patent, the object of the invention is to draw advantage from the use of the carbamide in the skin care preparation. According to claim 1, this is achieved in that carbamide envelops fatty acids and/or fatty acid compounds in such a way that the fat in the skin care cream is made accessible, at the same time as it is protected against oxidation. However, as already mentioned, a product of this kind is totally dependent on the presence of carbamide in the composition. In addition, it is stated in NO 19980711 (page 4) that the method described results in about only half of the omega-3 fatty acids being enveloped in such a mixture with carbamide, which presumably means that not all the omega-3 present is protected from oxidation. Accordingly, it is an object of the present invention to provide a skin care preparation (skin cream) which comprises fatty acids, specifically omega-3 fatty acids, which are protected against oxidation, so that the skin cream does not emit an odour after application to the skin. It is a further object to provide a skin cream having a much higher omega-3 fatty acid content than has been provided before, yet without the product oxidising and developing a rank odour, and also to provide a method for preparing a product of this kind.

The present invention relates to a skin care preparation (skin cream) comprising, among other ingredients, unsaturated fatty acids (omega-3 fatty acids), and which is prepared in such a way that the omega-3 fatty acids do not oxidise, even after application to the skin. This is achieved by mixing two emulsions where one is a water-in-oil emulsion (emulsion I) containing no omega-3 fatty acids, and the other is an oil-in-water emulsion (emulsion II) containing omega-3 fatty acids. The result is a new type of emulsion (emulsion III) which will be a water-in-oil emulsion. Without the mechanism of action having been established experimentally, and without having to commit to a particular theory, it is the inventor's belief that the omega-3 fatty acids in this new emulsion (emulsion III) are protected against oxidation because they are contained within small water particles, which in turn are surrounded by/dispersed in the homogeneous and continuous lipid phase from emulsion I, thereby preventing the product from turning rancid.

The invention will now be described in more detail, with reference to figures and examples.

Figure 1 : The figure shows emulsion III, which is a water-in-oil emulsion. The water is in the emulsion in the form of a dispersed phase (droplets), 2, 3, which is in a continuous lipid phase 1. About 15% of the water particles are from emulsion II 3, and contain omega-3 fatty acids 4.

In order to prepare a skin care preparation (skin cream) containing omega-3 fatty acids which are not oxidised, so as to avoid a rancid fish oil smell, an emulsion (emulsion III) has been prepared according to the invention by mixing together two other emulsions (emulsion I and emulsion II).

Emulsion I is a water-in-oil emulsion, e.g., a skin cream, which does not contain omega-3 fatty acids, and where the lipid content is relatively low, that is to say 15- 20%, preferably 17%. The water phase in this emulsion comprises from 80 to 85%, preferably 83%.

Emulsion II is an oil-in-water emulsion where the oil comprises from 66 to 80%, preferably 80%, whilst the water phase comprises from 20 to 34%, preferably 20%. The oil phase in the emulsion is composed of marine oils or concentrates or mixtures thereof, or a mixture of marine oils and vegetable oils. The marine oil used is preferably cod liver oil, and most preferably omega-3 fatty acids. If the oil is a fish oil, the omega-3 fatty acid content of the fish oil may be from 10 to 85%, preferably 20-60%, and more preferably 40%. The high oil content gives an emulsion of this kind high viscosity, which appears to help prevent the auto- oxidation of the polyunsaturated fatty acids.

To prepare a new type of skin cream according to the present invention, emulsion I and emulsion II can be mixed in a given ratio, e.g., in a ratio of respectively (80- 90): (20: 10), and preferably in the ratio of 85:15. The two emulsions are mixed by adding emulsion II to emulsion I at room temperature, whereupon they are gently stirred together, preferably without admission of air, until there is a visible homogeneity. The result is a new emulsion, called emulsion III, which will be a water-in-oil emulsion (Figure 1). In emulsion III the oil phase from emulsion I will form a homogeneous and continuous lipid phase 1. The water in emulsion III will be dispersed in the continuous lipid phase in the form of droplets 2, 3, which are consequently prevented from coming into contact with one another. A major portion of the droplets 2 consists of water from emulsion I. The droplets 3 which are from emulsion II constitute a substantially smaller portion of emulsion III as result of the mixture ratio, and the fatty acids 4 from emulsion II are found inside these 3 water droplets, and, according to the inventor, they are thus prevented from oxidising. The lipid phases in emulsions I and II are incompatible, and therefore have no possibility of forming a homogeneous lipid phase. As far as the inventor knows, an emulsion of this kind has not previously been described. In what follows the invention will be illustrated by means of examples, which should by no means be understood as defining the limits of the invention.

EXAMPLES

Example 1

The example illustrates a skin cream according to the present invention which contains omega-3 fatty acids.

The preparation of such a skin cream is carried out in the following manner: (i) first, a skin cream in the form of a water-in-oil emulsion (emulsion I) which does not contain omega-3 fatty acids is prepared, where the ratio between the lipid and the water phase is 17 and 85% respectively; (ii) an oil-in-water emulsion (emulsion II) is prepared, where the oil is fish oil containing omega-3 fatty acids, and where the ratio between the lipid and water phase is 80 and 20% respectively; (iii) emulsion I and emulsion II are mixed together by gentle stirring. Example 2

An emulsion I (skin cream: Hudpleiekrem, ScanHall A.s) is prepared as mentioned in Example 1, where the skin cream consists of about 83% purified water and the following components: stearic acid, palmitic acid, isopropylene myristate, propylene glycol, ceryl alcohol, glycol distearate, polysorbate 80, cetyl acetate, acetylate lanolin alcohol, stearyl alcohol, alcohol denate, triethanolamine, methylparaben, tocopheryl acetate, lactic acid, propyl paraben, fragrance, allantoin and polyethylene glycol-40 hydrogenated castor oil.

Furthermore, an oil-in-water emulsion which has the viscosity of a paste is used as emulsion II. During its preparation, this product has not been in contact with the air, which means that there has not been any oxidation of the fish oil in the product. This emulsion contains in addition vitamins E and C which act as anti- oxidants and play a major role in the defence against free radicals. Emulsion II

(Coromar™, ScanHall A.s) contains fish oil comprising 40% omega-3 fatty acids, in addition to water, eggs, vitamins (ascorbic acid, alpha-tocopherol, folic acid), flavouring (vanillin), preservative (potassium sorbate, sodium benzoate) sweetener (acesulpham K, sodium cyclamate, sodium saccharinate), acidity regulator (citric acid), stabiliser (guar seed powder, xanthan gum) and beta-carotene).

Example 3

A skin cream as disclosed in Example 2 was tested for odour after application to the skin.

Five people applied the skin cream to their hands, and even after 5-8 hours a rancid fish oil smell had not developed. This is due to the fact that the fatty acids or the fish oil in the cream is prevented from oxidising, despite the fact that the amount of fish oil added to the cream is considerably greater than what is known from other creams or ointments.

Claims

PATENT CLAIMS

1. A skin care preparation in the form of an emulsion, characterised in that the emulsion (emulsion III) consists of two other emulsions, emulsion I and emulsion II, where emulsion I is a water-in-oil emulsion and emulsion II is an oil-in-water emulsion, wherein a portion of the oil in emulsion III consists of omega-3 fatty acids that are prevented from oxidising.

2. A skin care preparation according to claim 1, characteri sed in that the omega-3 fatty acids prevented from oxidising consist of marine oils or concentrates or mixtures thereof, or a mixture of marine oils and vegetable oils.

3 A skin care preparation according to any one of claims 1-2, characteri sed in that the marine oil used is preferably a fish oil, and more preferably cod liver oil.

4. A skin care preparation according to any one of claims 1-3, characterised in that emulsion I is a water-in-oil emulsion containing no omega-3 fatty acids and emulsion II is an oil-in-water emulsion containing omega-3 fatty acids, and that emulsion I and emulsion II are present in a ratio of respectively (80-90):(20-10), and preferably 85:15.

5. A skin care preparation according to any one of claims 1-4, characterised in that emulsion III is a water-in-oil emulsion.

6. A skin care preparation according to any one of claims 1-5, char acterised in that emulsion I consists of a lipid phase of 15-20%, preferably 17%, and a water phase of 80-85%, preferably 83%, and that emulsion II consists of a lipid phase of 66-80%, preferably 80%, and a water phase of 34-20%, preferably 20%.

7. A skin care preparation according to any one of claims 1-6, characteri sed in that the omega-3 fatty acid content of the marine oil used may be from 10 to 85%, preferably 20-60%, and more preferably 40%.

8. A skin care preparation according to any one of claims 1-6, characteri sed in that emulsion I is Hudpleiekrem (ScanHall A.s) and emulsion II is Coromar™ Omega-3 (ScanHall A.s).

9. A method for preparing a skin care preparation according to claim 1, characterised in that two separate emulsions are prepared, where one is a water-in-oil emulsion (emulsion I) and the other is an oil-in-water emulsion (emulsion II), and where these emulsions are mixed together carefully at room temperature until visible homogeneity is obtained and a new emulsion (emulsion III) is thus produced, and wherein a portion of the oil in emulsion III consists of omega-3 fatty acids which after the intermixing are prevented from oxidising.

10. A method according to claim 9, characterised in that the omega-3 fatty acids that are prevented from oxidising consist of marine oils or concentrates or mixtures thereof, or a mixture of marine oils and vegetable oils.

11. A method according to any one of claims 9-10, characterised in that the marine oil used is preferably a fish oil, and more preferably cod liver oil.

12. A method according to any one of claims 9-11, characterised in that emulsion I and emulsion II are mixed in a ratio of respectively (80-90):(20:10), preferably 85:15, and that emulsion II is a water- in-oil emulsion.

13. A method according to any one of claims 9-12, char acterised in that emulsion I consists of a lipid phase of 15-20%, preferably 17%, and a water phase of 80-85%, preferably 83%, and that emulsion II consists of a lipid phase of 66-80%, preferably 80%, and a water phase of 34-20%, preferably 20%.

14. A method according to any one of claims 9-13, characterised in that the omega-3 fatty acid content of the marine oil used may be from 10 to 85%, preferably 20-60%, and more preferably 40%.

15. A method according to any one of claims 9-14, characterised in that emulsion I is Hudpleiekrem (ScanHall A.s) and emulsion II is Coromar™ Omega-3 (ScanHall A.s).

16. Use of a skin care preparation according to any one of claims 1-8, for application to the skin.