Use of a composition as a cosmetic product.

The present invention relates to the use of a composition as a cosmetic product including a liquid and powdery cosmetic compositions comprising an inclusion product having a slightly water-soluble component with a hydroxy-alkylated cyclodextrin (hereinafter abbreviated as "HACD") formulated therein. More specifically, the present invention relates to a liquid cosmetic composition and a powdery cosmetic composition having improved product characteristics such as useability and stability, and effectively preventing skin roughening, due to the formulation of an inclusion product with HACD.

Cosmetic compositions well known in the art such as cosmetic water, lotions, beauty lotion, etc. contain, in addition to a main component such as water or alcohol, various slightly water-soluble components such as oils and fats, physiologically active substances, UV-ray absorbers, antiphlogistics, and perfumes, formulated by utilizing a small amount of a surfactant for enhancing the useability and utility thereof.

Also, powdery cosmetic compositions used for an amelioration of skin sorenes due to a sunburn contain a slightly water-soluble component such as a skin activator and a drug in a water-soluble powdery base.

In cosmetic compositions, it is well known that a quantitative limitation will arise when formulating the above-mentioned slightly water-soluble components, and therefore, for example, when solubilizing slightly water-soluble components in large amounts and in a uniform state, a large amount of ethanol or a polyol must be formulated, but the formulation of these components cause the problem of skin irritation. Also, if the slightly water-soluble components are not uniformly dissolved, a problem arises in that the cosmetic composition becomes turbid or loses its transparency, to thereby reduce its commercial value. Further, the slightly water-soluble components formulated also react with the other components, to thereby cause a deterioration and decomposition of the other components.

To solve these problems, Japanese Unexamined Patent Publication (Kokai) No. 61-227517 discloses a technique by which the above-mentioned components are formulated by utilizing the inclusion action of a cyclodextrin polymer. But, according to this method, since a cyclodextrin polymer per se having a constant quality is difficult to obtain, and because the polymer is viscous and slightly soluble in water, satisfactory results could not be obtained.

Also, in powdery cosmetic compositions of the type which are commercially available in powdery form, to which water is added before use, since this type of cosmetic is solubilized between the palms while using only of a small amount of water, the slightly water-soluble components are not uniformly dissolved, and therefore, a coarse feeling remains during use and the pharmacological effect thereof is not fully exhibited. As means for solving these problems, attempts have been made to increase the amount of the surfactant or to utilize the inclusion action of a cyclodextrin polymer, but good results could not be obtained for the same reason as mentioned above. Also, none of the cyclodextrin polymers provides a satisfactory skin roughening prevention effect.

Recently, there is a trend toward using a base makeup on the skin, primarily directed to beautifying the skin, and thus there is a need for a cosmetic composition which effectivly prevents skin roughening and retains the preferable characteristics of a cosmetic composition.

SUMMARY OF THE INVENTION

Accordingly, the objects of the present invention are to eleminate the above-mentioned disadvantages of the prior art and to provide a composition for use as a cosmetic product having a high degree of safety, an excellent solubility, useability, and stability, and providing an effective skin roughening prevention, by utilizing the inclusion action of HACD, which can be readily solubilized without using a large amount of a solubilizing agent such as ethanol or a polyol.

Other objects and advantages of the present invention will be apparent from the following description.

In accordance with the present invention, there is provided a composition for use as a cosmetic product comprising an inclusion product having a slightly water-soluble component with a hydroxyalkylated cyclodextrin formulated therein.

The HACD used in the present invention is a cyclodextrin well known in the art as a cyclic oligosaccharide, having a hydroxyalkyl group introduced into the hydroxyl group thereof, namely hydroxypropyl-β-cyclodextrin.

This special HACD used in the present invention has an excellent solubility in hydrophilic solvents such as water, compared with the CD of the prior art as shown in Table 1, and in the present invention any desired amount of a slightly water-soluble component can be formulated in a cosmetic composition by utilizing this property and the inclusion action of HACD. <tables id="tabl0001" num="0001"><img file="EP0366154B1_D0001.tif" /></tables>

Several processes for preparing HACD are known in the prior art, and an example thereof is shown below.

A 100 g amount of β-CD (manufactured by Nihon Shokuhin Kako, tradename: Seldex N) was dissolved in 150 ml of a 20% aqueous NaOH, 50 ml of propylene oxide was gradually added dropwise while maintaining the temperature at 30°C, and the reaction was continued for 20 hours under stirring. After completion of the reaction, the pH was adjusted to 6.0 with hydrochloric acid, and the product placed in a dialyzing film tube to effect desalting under running water for 24 hours. Then the product was dried by a lyophilizer, to give about 90 g of a propylated β-cyclodextrin. The degree of substitution of the hydroxypropylated β-cyclodextrin was found to be 5.1.

The slightly water-soluble component to be used in the present invention means a cosmetic component which is substantially insoluble or only slightly soluble in water. The examples include UV-ray absorbers such as benzophenone, 4-t-butyl-4'-methoxydibenzoylmethane, glyceryl dimethoxycinnamate ethylhexanoate, p-aminobenzoate, octyl p-methoxycinnamate, and phenyl salicylate; antiphlogistics such as L-menthol and camphor; preservatives such as ethyl p-benzoate, propyl p-benzoate, and butyl p-benzoate; and sterilizers such as glycyrrhizinic acid, triclosane, and dibutylhydroxy toluene; single substance perfumes such as linalool, linalyl acetate, limonene, citral, methylionone, benzyl acetate, methyldehydrojasmonate, phenylethyl alcohol, muskketone, santalol, a-hexylcinnamicaldehyde, TEC, and citronelol, and composed perfumes comprising mixtures thereof.

The property of these substances may be either liquid or crystalline, and they may be used either alone or in the form of a mixture.

When preparing the inclusion product using such a slightly water-soluble component and HACD, the well-known methods as described below may be employed.

To an aqueous 20 to 60% by weight of HACD is added and mixed 0.01 to 0.15 part by weight of the required component as mentioned above per 1 part by weight of HACD, followed by stirring and mixing at 20 to 50°C. The stirring may be carried out at 50 to 3000 rpm, and the inclusion reaction time is 2 to 8 hours.

The inclusion product thus obtained is solubilized or emulsified in the aqueous solution, and can be used as such, but the aqueous solution can be also finely powdered by a treatment such as freeze drying or spray drying before use. In the liquid or non-powdery cosmetic composition according to the first embodiment of the present invention, a formulation is possible in either the the reaction mixture or the finely powdered state.

The content of the above-mentioned inclusion product in the liquid cosmetic composition of the present invention, which is influenced by the kind of slightly water-soluble component included and the type of cosmetic composition, is preferably up to 25% by weight, more preferably 0.5 to 15% by weight of the entire cosmetic composition in the finely powdered state. Although it is technically possible to formulate an amount of more than 25% by weight, a drawback arises in that the cosmetic composition becomes sticky during use.

The liquid or non-powdery cosmetic composition of the first embodiment of the present invention, in addition to the above components, can further formulate other conventional cosmetic components corresponding to the commercial product feature, for example, humectants such as hyaluronic acid; water-soluble drugs such as vitamin C; viscosity controllers; pH controllers; preservatives; sterilizers, antioxidants; perfumes; and dyes.

In the powdery cosmetic composition of the second embodiment of the present invention, the same inclusion product as used in the cosmetic composition of the first embodiment of the present invention can be used, but since the dried product form is maintained until immediately before use, preferably the inclusion product of HACD is added in the dry state to other water-soluble base components. The amount of the inclusion product of HACD in the powdery cosmetic composition is preferably up to 50% by weight, more preferably 1.0 to 40%, of the entire powdery cosmetic in the finely powdered state. Although no substantial problem arises with an amount of more than 50% by weight, the cosmetic does become sticky during use.

In the powdery cosmetic composition of the second embodiment of the present invention, soluble powder bases such as D-mannitol and lactose other than the inclusion product of HACD, and corresponding to the commercial product feature, other cosmetic components, for example, humectants such as hyaluronic acid; water-soluble drugs such as vitamin C; viscosity controllers; pH controllers; preservatives; sterilizers; antioxidants; perfumes; and dyes can be also formulated.

According to the present invention, slightly water-soluble components which can be limitedly formulated in the prior art can be formulated in any desired amount without the aid of alcohol, whereby liquid or powdery cosmetic compositions are obtained which have an excellent transparency, stability, safety, useability, and effectively prevent skin roughening. Also, in the present invention, since the slightly water-soluble substance is included with HACD, other components in the liquid or powdery cosmetic compositions are not affected thereby, and thus a long term stabilization is obtained.

Further, in the second aspect of the present invention, an effect is obtained whereby the powdery cosmetic composition is completely dissolved with a small amount of water during use.

EXAMPLES

The present invention will now be further illustrated in detail by the following Examples, wherein "parts" in the formulation are all by weight unless otherwise noted.

Example 1: Humectant Cosmetic Water

Preparation 1

<tables id="tabl0002" num="0002"><img file="EP0366154B1_D0002.tif" /></tables>

Preparation 2

<tables id="tabl0003" num="0003"><img file="EP0366154B1_D0003.tif" /></tables>

Preparation method

The hydroxypropylated CD mixture of (1) (2.5 g) was dissolved in 40 g of deionized water, (2) and (3) were added thereto, and the mixture was stirred to obtain the Preparation 1 containing the inclusion product of the hydroxypropylated CD mixture.

Then the above Preparation 1 was added to the above Preparation 2 to obtain a humectant cosmetic water having a drug stably formulated therein.

When the hydroxypropylated CD mixture was omitted from the above-described composition, the resultant cosmetic water did not have a good stability, in that the oil components were separated from the drug over a lapse of time.

Example 2: Systemic Lotion

Preparation 1

<tables id="tabl0004" num="0004"><img file="EP0366154B1_D0004.tif" /></tables><tables id="tabl0005" num="0005"><img file="EP0366154B1_D0005.tif" /></tables>

Preparation 2

<tables id="tabl0006" num="0006"><img file="EP0366154B1_D0006.tif" /></tables>

Preparation method

To a solution of (1) dissolved in deionized water were added UV-ray absorbers (2), (3) and (4), followed by stirring, to prepare the Preparation 1 containing the inclusion product of hydroxypropylated β-CD.

Then the above Preparation 1 was added to the Preparation 2 to obtain a systemic lotion having UV-ray absorbers stably formulated therein:

When the hydroxypropylated β-CD was omitted from the above-described composition, lotion had a poor stability, in that the UV-absorbers were separated over a lapse of time.

Example 3: Astringent

Preparation 1

<tables id="tabl0007" num="0007"><img file="EP0366154B1_D0007.tif" /></tables>

Preparation 2

<tables id="tabl0008" num="0008"><img file="EP0366154B1_D0008.tif" /></tables>

Preparation method

To a solution of (1) dissolved in deionized water were added (2), (3), and (4), followed by stirring, to obtain the Preparation 1 containing the inclusion product of the hydroxyethylated β-CD.

Then the above Preparation 1 was added to the Preparation 2 to obtain an astringent having a UV-ray absorber, perfumes, and a dye stably formulated therein.

Example 4: Nonalcoholic Cosmetic Water

Preparation 1

<tables id="tabl0009" num="0009"><img file="EP0366154B1_D0009.tif" /></tables>

Preparation 2

<tables id="tabl0010" num="0010"><img file="EP0366154B1_D0010.tif" /></tables>

Preparation method

To a solution of (1) dissolved in deionized water were added (2) and (3), followed by stirring, to prepare the Preparation 1 containing the inclusion product of the hydroxymethylated β-CD.

Then the above Preparation 1 was added to the Preparation 2 to obtain a nonalcoholic cosmetic water containing an antiphologistic and a perfume stably formulated therein.

Example 5: Powder Containing Cosmetic Water

Preparation 1

<tables id="tabl0011" num="0011"><img file="EP0366154B1_D0011.tif" /></tables>

Preparation 2

<tables id="tabl0012" num="0012"><img file="EP0366154B1_D0012.tif" /></tables>

Preparation method

To a solution of (1) dissolved in deionized water were added (2), (3), and (4), followed by stirring, to prepare the Preparation 1 containing the inclusion product of the hydroxybutylated β-CD.

Then the above Preparation 1 was added to the Preparation 2 to obtain a powder containing a cosmetic water having an antiphologistic and a perfume formulated stably therein.

Example 6: Action against Skin Roughening

Sample of the inclusion products having composed perfume included in CD prepared by dissolving 5 g of various CD or CD derivatives in 95 g of deionized water and adding 0.01 g of a composed perfume (linalol, linalol acetate, lavender oil, santalol, coumarine, etc.), followed by stirring, were used to determine the skin roughening prevention effect.

The hair at the back of 3 Hartley-strain guinea pigs weighing 700 to 850 g was cut with a pair of clippers, followed by a of depilation treatment. On day 4 after the hair was removed, 25 ml of an aqueous 3% sodium alkylbenzenesulfonate (LAS) solution was continuously applied once per day on 4 sites of the skin to which the depilation treatment was applied to cause skin roughening. Further, at the same sites, after coating the LAS solution, 50 ml of each of the above-mentioned samples was applied once per day.

The changes in the state of the skin on day 7 after the initiation of the LAS aqueous solution application were evaluated with regard to erythema and exfoliation according to the standards shown below; these are average values. Also, the totals of the respective average values of erythema and exfoliation are shown as the skin roughening score. The results are shown in Table 2.

Evaluation of Erythema

<tables id="tabl0013" num="0013"><table frame="all"><title>Table 2</title><tgroup cols="5" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="31.50mm" /><colspec colnum="2" colname="col2" colwidth="31.50mm" /><colspec colnum="3" colname="col3" colwidth="31.50mm" /><colspec colnum="4" colname="col4" colwidth="31.50mm" /><colspec colnum="5" colname="col5" colwidth="31.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Sample</entry><entry namest="col2" nameend="col2" align="center">Erythema</entry><entry namest="col3" nameend="col3" align="center">Exfoliation</entry><entry namest="col4" nameend="col4" align="center">Skin roughening score (Total)</entry><entry namest="col5" nameend="col5" align="center">Remark</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="center">Hydroxypropyl-β-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">0.2</entry><entry namest="col3" nameend="col3" align="char" char=".">0.6</entry><entry namest="col4" nameend="col4" align="char" char=".">0.8</entry><entry namest="col5" nameend="col5" align="left">Invention</entry></row><row><entry namest="col1" nameend="col1" align="center">α-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">0.7</entry><entry namest="col3" nameend="col3" align="char" char=".">2.0</entry><entry namest="col4" nameend="col4" align="char" char=".">2.7</entry><entry namest="col5" nameend="col5" align="left">Comparison</entry></row><row><entry namest="col1" nameend="col1" align="center">β-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">0.9</entry><entry namest="col3" nameend="col3" align="char" char=".">0.7</entry><entry namest="col4" nameend="col4" align="char" char=".">1.6</entry><entry namest="col5" nameend="col5" align="left">   "</entry></row><row><entry namest="col1" nameend="col1" align="center">Υ-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">0.5</entry><entry namest="col3" nameend="col3" align="char" char=".">1.1</entry><entry namest="col4" nameend="col4" align="char" char=".">1.6</entry><entry namest="col5" nameend="col5" align="left">   "</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="center">β-CD-polymer</entry><entry namest="col2" nameend="col2" align="char" char=".">1.1</entry><entry namest="col3" nameend="col3" align="char" char=".">1.2</entry><entry namest="col4" nameend="col4" align="char" char=".">2.3</entry><entry namest="col5" nameend="col5" align="left">   "</entry></row></tbody></tgroup></table></tables>

Although the skin roughening prevention effect is greater as the numerical value of skin roughening score is lower, as apparent from Table 2, it is obvious that the hydroxypropyl-β-CD of the present invention acts very effectively to prevent skin roughening, compared with the samples formulated for comparative purposes.

Example 7: Action on Corneum Turnover

To determine the effect on turnover of corneum, the respective samples were applied in the same manner as in Example 1 except that duncil chloride was applied on the same sites before the application of the 3% aqueous LAS solution of Example 11. From the change of a relative fluorescent value with a lapse of time, the days when only 50% of the original fluorescent value appeared were calculated. The results are shown in Table 3. The turnover of corneum is accelerated as the days in which 50% of the fluorescence disappears are lessened, suggesting progress against the skin roughening. <tables id="tabl0014" num="0014"><table frame="all"><title>Table 3</title><tgroup cols="3" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Sample</entry><entry namest="col2" nameend="col2" align="center">50% fluorescence disappearance days</entry><entry namest="col3" nameend="col3" align="center">Remark</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="center">Hydroxypropyl-β-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">4.7</entry><entry namest="col3" nameend="col3" align="left">Invention</entry></row><row><entry namest="col1" nameend="col1" align="center">α-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">3.8</entry><entry namest="col3" nameend="col3" align="left">Comparison</entry></row><row><entry namest="col1" nameend="col1" align="center">β-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">3.4</entry><entry namest="col3" nameend="col3" align="left">   "</entry></row><row><entry namest="col1" nameend="col1" align="center">γ-CD</entry><entry namest="col2" nameend="col2" align="char" char=".">3.7</entry><entry namest="col3" nameend="col3" align="left">   "</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="center">β-CD-polymer</entry><entry namest="col2" nameend="col2" align="char" char=".">2.7</entry><entry namest="col3" nameend="col3" align="left">   "</entry></row></tbody></tgroup></table></tables>

As apparent from Table 3, the hydroxypropyl-β-CD of the present invention is very effectively inhibits the corneum turnover, compared with the samples formulated for comparative purposes.