External composition containing Unsaturated fatty acid or its salt or ester

Abstract

To a polyunsaturated fatty acid or its salt or ester was added an antioxidative sesame component and ascorbic acid or an ascorbyl fatty acid ester. To the polyunsaturated fatty acid or its salt or ester, or an oil or fat containing the polyunsaturated fatty acid or its salt or ester having an peroxide value (PV) of 3.0 meq / kg or less and an acid value (AV) of 1.0 or less, and no odor in terms of sensory testing was mixed with an antioxidative sesame component, ascorbic acid or an ascorbyl fatty acid ester, and an external base material, under conditions preventing oxygen from mixing, and the mixture is quickly placed in a hermetic container. The above method provides an external composition containing a polyunsaturated fatty acid or its salt or ester, exhibiting enhanced oxidative stability, and consequently preventing the generation of peculiar odor and peroxides resulting from the oxidation of the polyunsaturated fatty acid.

Description

TECHNICAL FIELD [0001] The present invention relates to an external composition containing a polyunsaturated fatty acid or its salt or ester, exhibiting enhanced oxidative stability, and consequently preventing the generation of peculiar odor and peroxides resulting from the oxidation of the polyunsaturated fatty acid. Specifically, the present invention relates to an external composition exhibiting enhanced oxidative stability, prepared by adding an antioxidative component of sesame and an ascorbic acid or ascorbyl fatty acid ester to the polyunsaturated fatty acid or its salt or ester, and which is not affected by oxidation. For example, it does not generate an odor resulting from oxidation when it is applied to skin. The present invention also relates to an external composition used for curing inflammatory skin diseases. [0002] In the present invention, the polyunsaturated fatty acid refers to a fatty acid having at least three double bonds. [0003] In the present invention, the e...

AI Technical Summary

Benefits of technology

[0020] The object of the present invention is to provide an external composition containing a polyunsaturated fatty acid or its salt or ester, exhibiting extremely enhanced oxidative stability. Specifically, the present invention provides an external composition containing a polyunsaturated fatty acid, such as EPA, and which does not generate odors or peroxides resulting from oxidation when it is applied to skin.

[0021] The inventors of the present invention have conducted intensive research in order to enhance the oxidative stability of oils and fats (oils and fats containing a high proportion of polyunsaturated fatty acid, such as oils of fish and aquatic animals). As a result, the inventors found that the oxidative stability of oils and fats can be extremely enhanced by adding an antioxidative component of sesame, such as sesamol, an ascorbic acid or ascorbyl fatty acid ester, and tocopherol in combination, and thus accomplished the present invention.

[0030] The present invention provides an external composition exhibiting oxidative stability extremely superior to the known external compositions containing a polyunsaturated fatty acid or the like. The present invention can also provide external medical drugs, external quasi drugs, and cosmetic preparations containing a polyunsaturated fatty acid or the like, such as EPA, which has not been put into practical use as external preparations due to an odor resulting from oxidation, in spite of its efficacy. Since the composition of the present invention exhibits superior oxidative stability, it can be easily produced and preserved even though such a polyunsaturated fatty acid is used. Also, the polyunsaturated fatty acid content can be increased.

Problems solved by technology

However, no decisive cure has not yet been found for allergodermia, and accordingly a safe therapeutic drug is desired which produces satisfactory therapeutic effects without side effects.

The ingestion of fish oil causes AA on cell membranes to be replaced with EPA, consequently reducing the production of mediators from the AA.

However, oils and fats containing polyunsaturated fatty acids exhibit very low oxidative stability.

However, no perfect method has been found yet, and thus there are various limits in use, such as of product type, distribution temperature, content, and storage conditions.

Although many patent applications have been filed for use of EPA or the like as an antiallergic drug, no invention has been put in practical use (for example, Japanese Unexamined Patent Application Publication Nos. 2-290812 and 6-62795).

Patent applications for use of EPA or the like as an external preparation also have been filed (Japanese Unexamined Patent Application Publication Nos. 3-90046, 8-109128, 6-298642, and 7-112913), but they have not been put in practical use.

However, the oxidation stabilities of fish oils and other oils and fats having extremely low oxidative stability (whose fatty acids have at least four double bonds) cannot be sufficiently enhanced by only such combinations of antioxidants and synergists.

It is however reported that sesamol is not effective for oils and fats exhibiting extremely low oxidative stability, such as fish oil (NOF Corporation, from fiscal Heisei 4 (1994) to Heisei 8 (1996), DHA Koudo Seisei Chushutsu Gijutsu Kaihatsu Jigyo, Kekka Gaiyou (DHA Koudo Seisei Chushutsu Gijutsu Kenkyu Kumiai) pp.

However, they are not effective for oils and fats exhibiting extremely low oxidative stability, such as fish oil, if they are used alone, and even their combined use with tocopherol does not produce satisfactory effects.

Although some of the antioxidants use sesamol and an ascorbic acid ester in combination, they do not produce effects particularly superior to other antioxidants.

This is probably because the combination of sesamol and an ascorbic acid ester does not produce superior effects.

In addition, the thermal instability of the antioxidants may affect antioxidant properties.

Since external preparations are spread on the surface of skin to come into contact with oxygen at a large area, they are liable to stand in a state to be oxidized and are, in addition, allowed to stand in such a state for a long time.

Also, stains of EPA or the like on clothing are difficult to remove by normal washing, and their odor remains for a long time.

EPA and the like have such a disadvantage in using as drugs in practice, in spite of their efficacy.

Furthermore, it has generally known that peroxides produced by oxidation of EPA or the like harmfully affect living bodies.

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