JP5825815B2 - Material for reducing skin contact amount of antiseptic contained in external preparation for skin and reducing method - Google Patents

Description

The present invention relates to a material for reducing the amount of skin contact with a preservative contained in an external preparation for skin and a method for reducing the amount.

Conventionally, for external preparations such as skin external preparations such as emulsions, creams, lotions, packs, cleaning agents, foundations, and other quasi-drugs, dispersions, ointments, creams, external use liquids, etc. Alternatively, preservatives such as parabens, sodium benzoate, sodium dehydroacetate, and phenoxyethanol are blended in order to kill and improve the preservability of the external preparation for skin.

However, it has been reported that some external skin preparations containing a preservative such as parabens, sodium benzoate, sodium dehydroacetate, phenoxyethanol, etc., feel a sense of irritation caused by the preservative during use.

On the other hand, prepare skin external preparations that do not contain preservatives such as parabens, sodium benzoate, sodium dehydroacetate, and phenoxyethanol, or reduce the amount, for users who feel irritation caused by preservatives during use Although attempts have been made, in order to prevent microbial contamination during the manufacturing process, so-called primary contamination, a sterile room or similar equipment is prepared to keep the manufacturing environment sterile, and manufacturing workers are also required to perform aseptic operations. In addition, a strict manufacturing process must be held at a higher cost than when manufacturing an external preparation for skin containing a preservative.

Furthermore, in the above-mentioned cosmetics that do not use preservatives, so-called preservative-free (paraben-free) or a small amount of preservatives, contamination of the contents due to the return of cosmetics to which various bacteria have adhered, so-called secondary In order to avoid contamination, a container is disclosed for preventing the cosmetics once removed from being returned. (Patent Document 1) However, an increase in the number of parts and the number of assembly steps cannot be denied.

In addition, attempts have been made to reduce skin irritation caused by preservatives by filling or contacting a skin external preparation with a container or member made of a preservative-adsorbing material. (Patent Document 2)

JP2002-17439 JP 2003-335631 A

However, in the method of filling the skin external preparation into a container or member composed of a preservative-adsorbing material, the inventors adsorb the preservative contained in the skin external preparation during the storage period.

In other words, when a skin external preparation is filled in a container composed of a preservative-adsorbing material, the preservative amount of the external skin preparation after filling is reduced by the adsorption of the preservative to the raw material. Will decrease before use.
Therefore, when the user opens the skin external preparation filled in the container and the use is terminated until the end of use, the initial sufficient antiseptic effect may be exhibited. Therefore, the growth of microorganisms occurs, and the external preparation for skin changes in quality, causing problems such as odor and cloudiness.
Secondary contamination by so-called microorganisms occurs, and the antiseptic effect cannot be fully exhibited against this contamination.

Therefore, as a result of intensive studies to solve the above-mentioned problems, the present inventors have shortened a preservative for skin external preparations containing parabens, sodium benzoate, and phenoxyethanol in order to improve the storage stability of the external preparation for skin. The present inventors have found a skin contact amount reducing material that can be reduced in time. For those who feel irritation due to the preservative, the amount of the preservative was reduced by adsorbing the preservative contained in the external preparation for skin by using the preservative skin contact amount reducing material of the present invention. The present inventors have also found a method that can be used without feeling the irritation of the preservative by applying to the skin later.
According to this method, it is possible to prevent so-called secondary contamination of microorganisms from outside during use until the use of the external preparation for skin is finished without affecting the storage stability of the external preparation for skin.
In addition, the preservative contained in the external preparation for skin at the time of use can be rapidly reduced.
As a result, it became possible to reduce the user's irritation feeling due to the antiseptic contained in the external preparation for skin.

As a result of examining various materials in order to solve the above problems, the present inventors have found that ethylene-vinyl acetate copolymer has a rapid and high adsorptivity to preservatives such as parabens, sodium benzoate, and phenoxyethanol. Found to have.

That is, in the present invention, by first bringing a skin external preparation containing a preservative into contact with a material containing an ethylene-vinyl acetate copolymer, parabens, sodium benzoate, and phenoxyethanol contained in the external skin preparation are converted into an ethylene-vinyl acetate copolymer. It is possible to reduce skin irritation because the amount of the preservative is reduced when it is adsorbed quickly and efficiently to the contained material and then applied to the skin.

According to the present invention, when used on the skin, the skin external preparation is brought into contact with a material having rapid preservative adsorptivity, and applied to the skin after adsorbing the preservative, whereby the skin external preparation is used. The skin contact amount of the preservative contained can be reduced, and skin irritation can be reduced.
Furthermore, there is no need to take special preventive measures against microbial contamination in the manufacturing process, so-called primary contamination, and without adversely affecting the preservability of the skin external preparation. It also becomes possible to prevent so-called secondary contamination of microorganisms from the outside.

In the present invention, the external preparation for skin means all compositions externally applied to the skin. For example, a composition applicable as a skin external preparation such as cosmetics such as emulsions, creams, lotions, packs, cleaning agents, foundations, quasi-drugs, external medicines such as dispersions, ointments, creams, and external liquids. Say. The form of the external preparation for skin such as liquid, cream, powder, solid and the like is not limited. The form having fluidity is particularly suitable, but when the method for reducing the amount of skin contact with the preservative contained in the external preparation for skin of the present invention is applied, the external form of the skin having no fluidity such as powder or solid Fluidity can also be imparted by adding a liquid to the agent.

The ethylene-vinyl acetate copolymer (ethylene / vinyl acetate copolymer) used in the present invention is a polymer obtained by copolymerizing ethylene and vinyl acetate, and is generally abbreviated as EVA.
The content of vinyl acetate contained in the ethylene-vinyl acetate copolymer is not particularly limited, but is preferably 3 to 40%, more preferably about 10 to 25%.
For example, a commercially available ethylene vinyl acetate copolymer 25 (vinyl acetate content 25%) manufactured by Wako Pure Chemical Industries, Ltd. is preferably used.

The material containing the ethylene-vinyl acetate copolymer used in the present invention can be used in the form of a cotton puff, a makeup sponge, a pack sheet, a gauze, a bottle cap, or a dispenser nozzle.
Regarding the form, it is sufficient that the external preparation for skin containing a preservative and the ethylene-vinyl acetate copolymer can be brought into contact with each other, and the material containing the ethylene-vinyl acetate copolymer may have a large surface area such as gauze, puff or sponge. In this case, the portion in contact with the external preparation for skin containing the preservative becomes large, and the preservative can be removed more efficiently.

For example, a material containing an ethylene-vinyl acetate copolymer can be easily coated by impregnating the ethylene-vinyl acetate copolymer with an ethylene-vinyl acetate copolymer solution after impregnating the cotton-puff, makeup sponge, gauze and other cosmetics with the ethylene-vinyl acetate copolymer solution. Can be created.
The coating amount of the ethylene-vinyl acetate copolymer can be adjusted by changing the concentration of the ethylene-vinyl acetate copolymer solution.

In addition, the ethylene-vinyl acetate copolymer itself may be made into a fiber, or the ethylene-vinyl acetate copolymer and another polyolefin may be blended into a fiber to be used as a nonwoven fabric.
Examples of the polyolefin include hydrocarbon-based polyolefins such as polyethylene and polypropylene. The structure of the ethylene-vinyl acetate copolymer and the polyolefin fiber is not particularly limited, and examples thereof include fibers having a core-sheath structure in which polyolefin is a core component and ethylene-vinyl acetate copolymer is a sheath component. The ratio of the core and the sheath can be arbitrarily used.
Nonwoven fabrics containing an ethylene-vinyl acetate copolymer can be produced using various known techniques. For example, a wet manufacturing method in which fibers are suspended in water uniformly and made into a sheet shape with a wire mesh, etc., an air raid method in which fibers are scattered in the air and then collected in a wire mesh to form a card, or spinning. Examples thereof include a spun bond method and a melt blow method in which a web is directly formed from a machine. Furthermore, when manufacturing a nonwoven fabric, you may use additives, such as surfactant for improving the dispersibility of a fiber, and polyvinyl alcohol for improving the entanglement of a fiber. These nonwoven fabrics may be a single layer or a laminate of two or more different types of nonwoven fabrics.

As another form, it can be made by impregnating a makeup sponge with an ethylene-vinyl acetate copolymer solution and then drying, and coating the makeup sponge with an ethylene-vinyl acetate copolymer.
Alternatively, the ethylene-vinyl acetate copolymer itself may be made into a foam by a method such as a press-crosslinking foam molding method and molded into a shape such as a makeup sponge. At that time, pigments may be used as fillers (calcium carbonate, silica, clay, etc.), rubbers for improving elasticity and heat resistance (natural rubber, styrene / butadiene rubber, ethylene propylene rubber, etc.) and colorants. good.

By doing in this way, it can be freely formed in the form which does not touch the contents during a preservation period, but contacts or passes at the time of use.

The content of ethylene-vinyl acetate copolymer in the preservative-adsorbing material used in the present invention is preferably 2% by weight or more, and is in direct contact with skin such as cotton puff, makeup sponge, pack sheet, gauze, etc. When used in such a form, it is preferably 2 to 30% by weight, particularly preferably 5 to 20% by weight. When the ethylene-vinyl acetate copolymer content exceeds 30% by weight, the properties are hard and the possibility of damaging the skin surface increases, which is not suitable for the original purpose of reducing the irritation to the skin when using a skin external preparation. Further, if the ethylene-vinyl acetate copolymer content is less than 2% by weight, sufficient preservative adsorption performance may not be obtained.

Preservatives that can be expected to be reduced, which are objects of the present invention, are parabens, sodium benzoate, and phenoxyethanol.
Usually, the antiseptic | preservative contained in a skin external preparation is mix | blended in the ratio which can prevent the microbial contamination at the time of skin external preparation manufacture, and can maintain the preservability during a preservation | save period.

Skin external preparations that are the subject of the present invention include preservatives, aqueous components, oily components, plant extracts, animal extracts, powders, surfactants, oils, alcohols, pH adjusters, preservatives, antioxidants, It is prepared by mixing thickeners, pigments, fragrances and the like as necessary and blending them appropriately. Moreover, the skin external preparation used as the object of this invention can be manufactured by normal factory equipment, and can be filled in a container by a conventional method. The dosage form of the external preparation for skin of the present invention is not particularly limited, and may be various dosage forms such as lotion, emulsion, cream, pack, powder, spray, ointment, dispersion, and cleaning agent.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

<Example 1> Difference in preservative adsorbability depending on the material Measurement test 6 kinds of preservatives commonly used for skin external preparations, such as methylparaben, ethylparaben, sodium benzoate, sodium dehydroacetate, phenoxyethanol and salicylic acid, the degree of adsorption to various materials Was measured. A preservative aqueous solution shown in "Table 1" was prepared, and the preservative aqueous solution / material was added at a weight ratio of 5/1 to a plastic bag with a chuck (Unipack, Production Japan Co., Ltd.) and allowed to stand at room temperature for 1 hour. Thereafter, the aqueous solution was recovered, the amount of the preservative was quantified by liquid chromatography, and the preservative adsorption rate of the material was calculated by comparison with the amount of the preservative before the treatment with the material. The preservative adsorption rate was calculated by “Formula 1”. The results are shown in “Table 2”.
Among the materials used, lyocell is one of regenerated cellulose fibers, and is obtained by spinning a solution in which cellulose itself is dissolved in a solvent, such as acetate fibers, without going through a derivatization process. Tencel is a trade name of Coatles. Cupra is copper ammonia rayon and is a kind of recycled fiber.

The preservative adsorption rate was determined by the following formula.

Formula 1

The calculation was performed using the above formula.

* 1: Polyethylene terephthalate * 2: Polyethylene * 3: Polypropylene * 4: Ethylene-vinyl acetate copolymer * 5: Ethylene-vinyl alcohol copolymer

Table 2 shows the results of measuring the preservative adsorption properties of the materials. From the results shown in Table 2, a remarkable preservative-adsorbing effect was observed particularly in cotton + EVA and pulp + rayon + EVA containing ethylene-vinyl acetate copolymer in the raw material. The material containing ethylene-vinyl acetate copolymer showed strong adsorption effect especially on parabens of methylparaben and ethylparaben.

<Example 2> Measurement test of difference in preservative adsorbability depending on ethylene-vinyl acetate copolymer content In the experiment of <Example 1>, methylparaben was found to have a particularly strong adsorption effect on a material containing ethylene-vinyl acetate copolymer. Regarding ethylparaben, the relationship between the content of ethylene-vinyl acetate copolymer in the material and the adsorptivity was investigated.
The ethylene-vinyl acetate copolymer-containing material was prepared by dissolving an ethylene-vinyl acetate copolymer (Wako Pure Chemical Industries, Ltd., ethylene vinyl acetate copolymer 25 (vinyl acetate content 25%)) in tetrahydrofuran so as to have a content of 0.75% by weight. The product was sprayed onto a commercially available cotton using a glass sprayer, and after spraying, the product was allowed to stand at room temperature overnight and dried.
The ethylene-vinyl acetate copolymer content of the ethylene-vinyl acetate copolymer-containing material was adjusted by adjusting the amount of ethylene-vinyl acetate copolymer sprayed on the cotton and finally having a content of 1 to 20% by weight. . The ethylene-vinyl acetate copolymer concentration was confirmed by measuring the dry weight of the cotton before and after spraying.
Next, a preservative aqueous solution shown in “Table 3” was prepared, and the preservative aqueous solution / ethylene-vinyl acetate copolymer-containing material was added to a plastic bag with a chuck (Unipack, Production Japan) at a ratio of 5/1 for 1 hour at room temperature. Left under. Thereafter, the aqueous solution was recovered, the amount of the preservative was quantified by liquid chromatography, and the preservative adsorption rate of the material was calculated by comparison with the amount of the preservative before the treatment with the ethylene-vinyl acetate copolymer-containing material. The preservative adsorption rate was calculated by “Formula 1”. The results are shown in “Table 4”.

Table 4 shows the results of a test for measuring the difference in preservative adsorption depending on the ethylene-vinyl acetate copolymer content. From the results shown in Table 4, a remarkable adsorption effect on methylparaben and ethylparaben was observed particularly in a material containing 2 to 20% by weight of ethylene-vinyl acetate copolymer in the material. In addition, although measurement data are not shown, dipotassium glycyrrhizinate, glucoside ascorbate, arbutin, and magnesium ascorbate are known as components useful for the skin blended in the preservative aqueous solution shown in Table 3 used in this experiment. Was not adsorbed on materials containing ethylene-vinyl acetate copolymer.
A similar test was conducted using an ethylene-vinyl acetate copolymer having a vinyl acetate content of 25% (ethylene vinyl acetate copolymer 20 (vinyl acetate content 20%) manufactured by Wako Pure Chemical Industries, Ltd.). Results were obtained.

<Example 3> Experiment on change in adsorption rate depending on adsorption time In the experiment of <Example 1>, methylparaben and ethylparaben, which showed a particularly strong adsorption effect on a material containing an ethylene-vinyl acetate copolymer, were brought into contact with the material. The relationship between time and adsorptivity was investigated.
The ethylene-vinyl acetate copolymer-containing material was prepared by dissolving an ethylene-vinyl acetate copolymer (Wako Pure Chemical Industries, Ltd., ethylene vinyl acetate copolymer 25 (vinyl acetate content 25%)) in tetrahydrofuran so as to have a content of 0.75% by weight. The product was sprayed onto a commercially available cotton using a glass sprayer, and after spraying, the product was allowed to stand at room temperature overnight and dried.
The ethylene-vinyl acetate copolymer concentration of the ethylene-vinyl acetate copolymer-containing material is adjusted by adjusting the amount of ethylene-vinyl acetate copolymer sprayed on the cotton, and finally adjusting the spray amount to a content of 20% by weight. Created. The ethylene-vinyl acetate copolymer concentration was confirmed by measuring the dry weight of the cotton before and after spraying.
Prepare the preservative aqueous solution shown in “Table 3” and add the preservative aqueous solution / ethylene-vinyl acetate copolymer-containing material to the plastic bag with a chuck (Unipack, Production Japan) in a ratio of 5/1, 5 minutes, 15 minutes. It was left at room temperature for 1 hour, 24 hours and 1 week. Thereafter, the aqueous solution was recovered, the amount of the preservative was quantified by liquid chromatography, and the preservative adsorption rate of the material was calculated by comparison with the amount of the preservative at the start. The preservative adsorption rate was calculated by “Formula 1”. The results are shown in “Table 5”.

"Table 5"

Table 5 shows the results of measurement tests of changes in contact time with materials and preservative adsorption rate. From the results shown in Table 5, the adsorption rate was as high as 70% for methyl paraben and 80% for ethyl paraben even when the standing time was 5 minutes.
Then, the results after the standing time of 5 minutes and the standing time of 168 hours were compared.
For comparison, the ratio of the adsorption rate for a standing time of 5 minutes / the adsorption rate for a standing time of 168 hours was determined.
70/78 = 0.897 for methylparaben
80/87 = 0.920 for ethylparaben
As a result, it was found that even in a short time of 5 minutes, the adsorptive power was not so different from the adsorptivity after 168 hours.
Regarding the adsorption effect of the present invention, the effect is exhibited in a short time. In other words, it is sufficient even in usage scenes in which the material containing ethylene-vinyl acetate copolymer is impregnated with the skin external preparation to be used and used immediately, that is, the skin is soaked with lotion and used immediately on the face. The effect can be expected.

<Example 4> The lotions shown in the practical use test examples 21 to 24 were prepared by a conventional method.
The ethylene-vinyl acetate copolymer-containing material was prepared by dissolving an ethylene-vinyl acetate copolymer (Wako Pure Chemical Industries, Ltd., ethylene vinyl acetate copolymer 25 (vinyl acetate content 25%)) in tetrahydrofuran so as to have a content of 0.75% by weight. The product was sprayed onto a commercially available cotton using a glass sprayer, and after spraying, the product was allowed to stand at room temperature overnight and dried.
The ethylene-vinyl acetate copolymer concentration of the ethylene-vinyl acetate copolymer-containing material is adjusted by adjusting the amount of ethylene-vinyl acetate copolymer sprayed on the cotton, and finally adjusting the spray amount to a content of 20% by weight. Created. The ethylene-vinyl acetate copolymer concentration was confirmed by measuring the weight of cotton before and after spraying.
By using this ethylene-vinyl acetate copolymer-containing material instead of a normal cotton puff, a usage test on skin irritation and usability was conducted.
The subject selected a panel that felt stimulation with methylparaben in advance.
The results are shown in “Table 7”. The values in the table represent “number of people who complained of skin irritation or who complained of usability / number of subjects”.
The usage procedure is as follows.
A) A cotton puff coated with 20% of an ethylene-vinyl acetate copolymer which is an ethylene-vinyl acetate copolymer-containing material was impregnated with lotion.
B) Apply to face.
C) After use, a questionnaire survey on the presence or absence of irritation and usability was conducted.

Numbers represent weight percent.

From the results of “Table 7”, it was confirmed that in Experimental Example 21 and Experimental Example 22 in which a material having antiseptic adsorption was used as a cotton puff, there was no person complaining of skin irritation and the usability was also good. It was done.
According to the results of “Table 7”, the skin external preparation is brought into contact with the preservative-adsorbing material of the present invention, and the preservative contained in the skin external preparation is adsorbed and applied to the skin. It was confirmed that the amount of the preservative contained in the skin was reduced.
This can provide a method for reducing the skin contact amount of the preservative contained in the topical skin preparation at the time of use without reducing the amount of the preservative contained in the topical skin preparation until just before use. It became clear that can be solved.

<Example 5>
30% by weight of ethylene-vinyl acetate copolymer (vinyl acetate content 25%) fiber 1.1 dtex x 7 mm (fineness x fiber length) and 0.1-0.6 dtex x 5-10 mm (fineness x fiber length), ultra-fine polyethylene terephthalate A raw material mixed with 70% by weight of fibers (TEPYRUS-PET, manufactured by Teijin Fibers Limited) was wet-made by the method described above to produce a nonwoven fabric. Next, three sheets of this non-woven fabric are overlapped on a paper machine, water-entangled with a water jet device, dried and wound up, and a three-layer structure in which one intermediate layer is sandwiched between two surface layers Manufactured non-woven fabric for cosmetics and beauty. The basis weight of one nonwoven fabric was 60 g / m2.
Immediately after impregnating the skin lotion of Experimental Example 21 with this, it was used by 5 panelists who felt irritation to methylparaben, and no irritation was felt.

By using the preservative skin contact amount reducing method of the present invention, it has an excellent performance of easily and rapidly reducing the amount of the preservative that comes into contact with the skin at the time of use. The present invention is an invention having such remarkable operational effects, and is an invention that makes a significant industrial contribution and is significant.

Claims (4)

Reduction containing 1 to 2 or more kinds of preservatives selected from ethylparaben, methylparaben, sodium benzoate, sodium dehydroacetate, and phenoxyethanol contained in a skin external material containing 2 to 30% by weight of an ethylene-vinyl acetate copolymer Material (except the container, except a mixture with polyethylene). The reducing material according to claim 1, wherein 2-30% by weight of ethylene-vinyl acetate copolymer is contained in cotton puff, makeup sponge, pack sheet, and gauze. Ethylene - preservative containing 2 to 30 wt% vinyl acetate copolymer reduces material (Except the container, except a mixture with polyethylene) in contacting the skin external preparation, ethylparaben contained in the external preparation for skin, methylparaben, One or more preservatives selected from sodium benzoate, sodium dehydroacetate and phenoxyethanol are adsorbed and then applied to the skin to apply ethyl paraben, methyl paraben, sodium benzoate and dehydroacetic acid to the skin. A method for reducing the amount of skin contact with one or more preservatives selected from sodium and phenoxyethanol (excluding medical practice). The reduction method according to claim 3, wherein 2 to 30% by weight of an ethylene-vinyl acetate copolymer is contained in a cotton puff, makeup sponge, pack sheet, or gauze.