JP2005120051A - External preparation for skin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an external preparation for skin capable of obtaining sufficient viscosity by a simple operation and excellent in stability with time and feelings upon use in ascorbic acid-based/alkoxysalicylic acid-based salt type bleaching agent. <P>SOLUTION: The external preparation for skin is obtained by formulating a salt type bleaching agent selected from an ascorbic acid-based compound/an alkoxysalicyclic acid-based compound with carrageenan and has 2,000-30,000 mPa s (at 30°C) viscosity. It is especially suitable that the carrageenan is an iota type. Higher thickening property is exhibited by further formulating a neutral salt including a monovalent cation such as sodium chloride, sodium hydroxide or potassium hydroxide or an alkali into the composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement in the viscosity and feeling of use of a skin external preparation, particularly a skin external preparation containing an ascorbic acid-based and / or alkoxysalicylic acid salt-type whitening agent.

  Market needs for cosmetics with a whitening effect are high, and as a result, ascorbates such as 2-ascorbic acid-2-glucoside potassium and phosphate-L-ascorbyl magnesium, alkoxysalicylates such as potassium 4-methoxysalicylate, etc. Is incorporated into cosmetics as a whitening agent.

On the other hand, in cosmetics, the feeling of use is one of the important factors in its commercial value. As a thickener for skin care preparations, carboxyvinyl polymers are widely used because of their high viscosity, freshness and low stickiness. Has been.
However, when the above ascorbic acid-based or alkylsalicylic acid-based salt whitening agent is added as a main ingredient, the thickening action of the carboxyvinyl polymer is drastically reduced, and when the amount of the carboxyvinyl polymer is increased, There was a problem of generating molecular debris.

In order to solve such problems, polysaccharides such as xanthan gum and agar, which are polysaccharide thickeners, have been used in the past. However, xanthan gum is not very thick, so to obtain the target viscosity. When blended in a high amount, there is a problem that the feeling of use becomes slimy or causes a sticky feeling.
In this way, in skin external preparations mainly composed of ascorbic acid-based or alkoxysalicylic acid-based salt whitening agents, there are few thickeners that can realize a fresh and non-sticky feeling, and therefore, variations in preparations were limited. . In particular, there were few variations in preparations such as a medium-viscosity whitening essence of 2,000 to 10,000 mPa · s and a high-viscosity whitening gel having a viscosity of 10,000 mPa · s or more.

In recent years, it has been reported that a hard and brittle gel formed using agar or gellan gum is mechanically pulverized, and the resulting microgel can function as a thickener with high salt resistance (Patent Documents). 1).
JP 2001-342125 A

However, since the above technique requires a pulverization process for microgel preparation, there is a problem that the process becomes complicated and the cost becomes high. Moreover, it was not sufficient in terms of stability such as water separation, and it was necessary to use in combination with other thickeners.
Therefore, in a composition containing a salt-type whitening agent, there has been a demand for a preparation that can be thickened and gelled by a simple method that does not require such a pulverization step, and that has excellent stability and usability.
The present invention has been made in view of the above-mentioned problems of the prior art. The purpose of the present invention is to obtain a sufficient viscosity with a simple operation in an ascorbic acid-based / alkoxysalicylic acid-based salt whitening compound-containing system, and is stable over time. An object of the present invention is to provide an external preparation for skin which is excellent in properties and feeling of use.

  As a result of intensive studies conducted by the present inventors in order to achieve the above-mentioned object, when using a carrageenan, particularly iota-type carrageenan in a salt-type whitening agent-containing system, the gelled at a low concentration and applied to the skin. In this case, the gel was easily crushed, and it was found that the gel was crisp, sticky and smooth, and also excellent in stability over time, and the present invention was completed.

That is, the skin external preparation according to the present invention comprises a salt whitening agent selected from ascorbic acid compounds and / or alkoxysalicylic acid compounds and carrageenan, and has a viscosity of 2,000 to 30,000 mPa · s (30 ° C).
In the external preparation for skin of the present invention, it is preferable that the carrageenan is iota type.
Moreover, in the skin external preparation of the present invention, the composition further contains one or more selected from neutral salts or alkalis containing monovalent cations in the composition, and the amount of neutral salt or alkali relative to the amount of carrageenan is by mass. It is preferable that it is 0.1 to 10 times.
Further, it is preferable that the neutral salt is sodium chloride and potassium chloride, and the alkali is sodium hydroxide and potassium hydroxide.

  According to the present invention, in a skin whitening external preparation containing a salt whitening agent as a main ingredient, carrageenan, in particular, iota type carrageenan is used as a thickener, so that a medium to 2,000 to 30,000 mPa · s / 30 ° C. When applied on the skin, it has a high viscosity, and it spreads evenly, has a fresh feeling of use, does not become slimy or sticky, and can be used as an external preparation for skin with no problems of stability such as water separation and viscosity reduction.

  In the present invention, the salt-type whitening agent means a whitening agent that is itself a salt type or is neutralized with an alkaline agent to form a salt. Ascorbic acid-based whitening agent, alkoxysaclic acid-based whitening agent Are preferably used. The external preparation for skin of the present invention contains at least one selected from these.

  Ascorbic acid-based whitening agents include ascorbic acid-based compounds composed of ascorbic acid and its derivatives. As a specific example, ascorbic acid includes L-ascorbic acid. Ascorbic acid derivatives include, for example, ascorbic acid inorganic acid esters such as L-ascorbic acid monophosphate, L-ascorbic acid-2-sulfate, dl-α-tocopherol 2-L-ascorbic acid diester; 2 Ascorbic acid glycosides such as -O-α-D-glucopyranosyl-L-ascorbic acid, and the like are preferable, and ascorbic acid-2-glucoside is preferable. Examples of salts of these ascorbic acid and ascorbic acid derivatives include alkali metal salts (Na salts, K salts, etc.), alkaline earth metal salts (Ca salts, Mg salts, etc.), ammonium salts, alkanolamine salts, amino acid salts, etc. In the present invention, an alkali metal salt is preferable.

（式中、Ｒはアルコキシ基である。）
Ｒは、炭素数１〜４のアルコキシ基であることが好適である。具体例としては、３−メトキシサリチル酸、３−エトキシサリチル酸、４−メトキシサリチル酸、４−エトキシサリチル酸、４−プロポキシサリチル酸、４−イソプロポキシサリチル酸、４−ブトキシサリチル酸、５−メトキシサリチル酸、５−エトキシサリチル酸、５−プロポシキサリチル酸、あるいはこれらの塩が挙げられる。塩はアルカリ金属塩（Ｎａ塩、Ｋ塩等）、アルカリ土類金属塩（Ｃａ塩、Ｍｇ塩等）、アンモニウム塩、アルカノールアミン塩、アミノ酸塩などが挙げられるが、本発明において好ましくはアルカリ金属塩である。 Moreover, as a suitable example of an alkoxy salicylic acid type whitening agent, what is shown by the following general formula (I) of Unexamined-Japanese-Patent No. 6-40886 is mentioned, for example.

(In the formula, R is an alkoxy group.)
R is preferably an alkoxy group having 1 to 4 carbon atoms. Specific examples include 3-methoxysalicylic acid, 3-ethoxysalicylic acid, 4-methoxysalicylic acid, 4-ethoxysalicylic acid, 4-propoxysalicylic acid, 4-isopropoxysalicylic acid, 4-butoxysalicylic acid, 5-methoxysalicylic acid, 5-ethoxysalicylic acid. , 5-proposixalicylic acid, or salts thereof. Examples of the salt include alkali metal salts (Na salt, K salt, etc.), alkaline earth metal salts (Ca salt, Mg salt, etc.), ammonium salts, alkanolamine salts, amino acid salts, etc. It is salt.

In the present invention, the blending amount of the salt whitening agent is not particularly limited as long as it is a range usually blended in cosmetics and pharmaceuticals.
In addition, in the skin external preparation of this invention, the said salt type whitening agent may be mix | blended after making it into the form of a salt, and may be neutralized in a composition with an alkali agent. Such an alkali agent for neutralizing a salt-type drug is not particularly limited as long as it can form a salt. For example, metal hydroxides such as sodium hydroxide and potassium hydroxide; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; organic acid salts such as sodium citrate, potassium malate and sodium lactate, and amino acids such as lysine Etc. Of these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferred.

  The external preparation for skin of the present invention is applied to the skin, and the pH is 5 to 8, particularly 6 to 7.5, from the viewpoint of the stability of the salt whitening agent and carrageenan. Is preferred. Care should be taken not to exceed this pH range, as excessive incorporation of alkaline agent increases the pH value.

  Carrageenan is a polysaccharide that is abundant in red algae and is a kind of galactan having a sulfate group. Carrageenan has different sulfate groups depending on the raw materials and extraction methods, and is divided into iota (ι) type, kappa (κ) type, and lambda (λ) type. It depends on. As the carrageenan used in the present invention, iota type is particularly suitable, and commercially available products include Aquagel I-2 (manufactured by Nitta Gelatin), Soagina MV-201 (manufactured by MRC Polysaccharide), and carrageenin CSI-1. (Manufactured by San-Ei Gen FFI Co., Ltd.) and the like are preferably used.

The gel formed by iota-type carrageenan is relatively soft and can be used without being pulverized. Moreover, the transparency of the gel is high, and there is almost no water separation from the gel during storage. On the other hand, kappa-type carrageenan has a very strong gelation ability and a hard gel, so it is difficult to spread it evenly on the skin at the time of use, and it is necessary to grind and use it like gellan gum and agar. . Moreover, it is inferior to the iota type in terms of transparency and stability (water separation). Lambda-type carrageenan has very weak gelling ability and cannot exhibit sufficient ability as a thickener of the present invention.
However, in the present invention, it is possible to use a small amount of kappa type and lambda type as long as iota-type carrageenan is used as a thickener main agent and the effect of the present invention is not affected.

  The amount of iota carrageenan is appropriately determined depending on the target viscosity. In the present invention, it is preferably 0.1 to 3% by mass, and more preferably 0.5 to 2% by mass in the external preparation. Preferably there is. If the blending amount is too small, the thickening effect is not sufficiently exhibited. If the blending amount is too large, the gel becomes hard, and the gel may not be easily crushed at the time of application or the spread may be poor.

Although the manufacturing method of the skin external preparation of this invention is not restrict | limited in particular, It is preferable to manufacture with the method including the following processes.
(A) Carrageenan is added to an aqueous medium containing water and dissolved at 70 to 80 ° C. to obtain an aqueous carrageenan solution.
(B) To the carrageenan aqueous solution of (A), a salt-type drug and, if necessary, an alkali agent and other components are preferably added under temperature conditions of 50 to 60 ° C., and mixed with stirring. If the temperature is too low, the gelation rate is fast, and it may take time to dissolve the drug uniformly. On the other hand, if the temperature is too high, thermal decomposition of a salt-type drug or the like may be caused.
(C) The mixed solution of (B) is allowed to cool or is stirred and cooled.

  The carrageenan gel prepared in this way is a plunging, relatively elastic gel that has a high yield value and is difficult to flow, but deforms significantly when the shear is greater than the yield value. Therefore, when stretched on the skin, the gel is crushed freshly and is very easy to spread. Also, there is no sliminess or stickiness. And also in the blending system of ascorbic acid type / alkoxysalicylic acid type salt whitening agent, the viscosity does not decrease like carboxyvinyl polymer, and a high viscosity can be obtained even in a small amount. Moreover, the obtained gel has high transparency, and has a very high aesthetic value in a gel-form preparation.

  The external preparation for skin of the present invention comprises the above-mentioned salt-type whitening agent and carrageenan (particularly, iota type) as essential components. The viscosity is preferably 2,000 to 30,000 mPa · s / 30 ° C. from the viewpoint of usability and stability.

In the present invention, when a water-soluble salt is further added in addition to the above essential components, the viscosity can be further increased.
Examples of such salts include organic acid salts, amino acid salts, and inorganic acid salts. Examples of the organic acid salt include alkali metal salts such as citric acid, lactic acid, oxalic acid, and succinic acid, ammonium salts, alkanolamine salts, and the like. Examples of amino acid salts include hydrochlorides such as glycine, alanine, proline, lysine, aspartic acid, and glutamic acid, metal salts, ammonium salts, alkanolamine salts, and the like. Examples of inorganic salts include carbonates, phosphates, nitrates, boric acid, sulfuric acid, sulfurous acid, halogen compounds, and hydroxides of metals such as sodium, potassium, calcium, and magnesium. Among these, in this invention, the neutral salt or alkali containing a monovalent cation is suitable, Especially preferably, they are sodium chloride, potassium chloride, sodium hydroxide, and potassium hydroxide. And when considering the influence etc. on pH, neutral salts, such as sodium chloride and potassium chloride, are especially preferable.
The amount of such neutral salt or alkali added is preferably 0.1 to 2% by mass and more preferably 0.5 to 1.5% by mass in the external preparation. If the addition amount is too small, the effect is not sufficiently exerted. On the other hand, even if it is added excessively, the viscosity increase corresponding to it cannot be obtained.

Moreover, in this invention, the component which can be normally mix | blended with a skin external preparation can be suitably mix | blended in the range which does not impair the effect of this invention. Examples include oils, surfactants, moisturizers, preservatives, stabilizers, powders, pigments, fragrances, pH adjusters, chelating agents, other medicinal ingredients, and the like.
The dosage form of the external preparation for skin of the present invention is not particularly limited, and various dosage forms such as a solubilizing system, an emulsifying system, and a dispersing system can be used. Specific examples of the preparation include an aqueous gel, an O / W emulsified gel, an O / W emulsion, and an O / W cream.

Hereinafter, the present invention will be described in more detail with reference to specific examples, but these do not limit the present invention. The blending amount is mass% unless otherwise specified.
First, the test method used in the present invention will be described.

(viscosity)
Using a rotational viscometer manufactured by Shibaura Systems, the viscosity (mPa · s / 30 ° C.) after 1 minute was measured at a rotor rotational speed of 10 rpm.

(PH)
The pH at 25 ° C. ± 2 ° C. was measured using a pH meter and electrodes manufactured by HORIBA.

(transparency)
The prepared sample was filled in a transparent glass container and judged visually.
○: High transparency.
Δ: Slightly cloudy translucent state.
X: Turbid and translucent state.

(Water separation)
The state when it was left to stand in a relatively low temperature thermostatic bath of −20 ° C. to 0 ° C. for one month and then returned to room temperature was observed.

(Feeling of use)
By an actual use test by 10 panelists, evaluations such as spread and slime when applying cosmetics to the skin were performed.
○: More than 5 respondents responded that it was easy to spread and not to be slim. △: 3 to 4 respondents responded that it was favorable to stretch and not to be stretched. Less than 2 people

Test Example 1 Type of thickener A gel was prepared with the following composition. Moreover, the thing which does not mix | blend ascorbic acid-2-glucoside (AA-2G), KOH, and a buffering agent was prepared similarly, and the viscosity measurement was performed.
(Table 1)
――――――――――――――――――――――――――――――――――――
Sample composition 1 2 3 4 5
――――――――――――――――――――――――――――――――――――
Thickener aqueous solution:
(1) Iota carrageenan * 1 1
(2) Gellan gum 1
(3) Agar 1
(4) Xanthan gum 1
(5) Carboxyvinyl polymer 0.5
(6) Ion-exchanged water Residue Residue Residual Residue Residual salt-type chemicals:
(7) AA-2G 2 2 2 2 2
(8) Na citrate 0.01 0.01 0.01 0.01 0.01
(9) Citric acid 0.09 0.09 0.09 0.09 0.09
(10) KOH 0.39 0.39 0.39 0.39 0.39
――――――――――――――――――――――――――――――――――――
Total 100 100 100 100 100 100
――――――――――――――――――――――――――――――――――――
viscosity
[Combination of (7) to (10)] 14300 7100 22000 10700 2500
[(7) ~ (10) no formulation] 300 400 23000 7500 68000
Transparency ○ △ × × ○
No ○ ○ × ○ ○ −
No slim No No No Yes −
Stability (water separation) ○ × × ○ −
−――――――――――――――――――――――――――――――――――――
* 1: Aqua Gel I-2 (Nitta Gelatin)

(Preparation method)
Samples 1-4: A thickener and ion-exchanged water were mixed and dissolved by heating at 80 ° C. to obtain a thickener aqueous solution. After cooling to 50 ° C., (7) to (10) were added, dissolved and allowed to cool.
Sample 5: A thickener and ion-exchanged water were mixed, and (7) to (9) were added and dissolved therein, and then (10) was added and mixed.

As can be seen from Table 1, the viscosity of the carboxyvinyl polymer (Sample 5) was significantly reduced in the ascorbate compounding system as compared to the case of no compounding.
Other thickeners gelled with an ascorbate-containing system, but gellan gum and agar (samples 2-3) are hard and non-flowable in gels, so it is difficult to evenly spread without application of gel pulverization. Met. In addition, these thickeners may cause water separation after long-term storage. In xanthan gum (sample 4), the transparency of the gel was low, and there was a slimy feeling and a stringiness.
On the other hand, when iota-type carrageenan was used (sample 1), a transparent gel having a high viscosity was obtained, and the gel spread well at the time of application. Water separation after long-term storage was not observed.

Test Example 2 Carrageenan Type Sample 1 was prepared in the same manner by changing the carrageenan type. The results are shown in Table 2.
(Table 2)
――――――――――――――――――――――――――――――――――――
Sample Carrageenan 1 6 7
――――――――――――――――――――――――――――――――――――
Iota Carrageenan * 1 1
Kappa Carrageenan * 2 1
Lambda carrageenan * 3 1
――――――――――――――――――――――――――――――――――――
Gel properties Soft, hard, liquid
Elastic gel Brittle gel No gelation Thickening * 4 ○ ○ ×
Transparency ○ △ ○
Noby ○ × ○
Numeri ○ ○ ×
Stability (water separation) ○ × ○
−――――――――――――――――――――――――――――――――――――
* 1: Aquagel I-2 (Nitta Gelatin)
* 2: Carrageenin CSK-1 (manufactured by Saneigensha)
* 3: Soagina LX22 (manufactured by MRC Polysaccharide)
* 4: ○ indicates thickening, and × indicates no thickening.

As shown in Table 2, in the case of kappa-type carrageenan, the gel was hard and pulverization was necessary for use. The transparency and stability of the gel were also low compared to the iota type. Lambda-type carrageenan did not gel in the ascorbate-containing system.
Therefore, in the present invention, it is preferable to use iota-type carrageenan.

Test Example 3 Addition of salt The viscosity of a system in which NaCl and CaCl ₂ were further added as salt to Sample 1 was examined. The amount of increase by NaCl or CaCl ₂ was adjusted by decreasing the amount of ion-exchanged water. The results are shown in Table 3.
(Table 3)
――――――――――――――――――――――――――――――――――――
Sample Cation 1 8 9 10 11 12
――――――――――――――――――――――――――――――――――――
NaCl − 0.5 1 1.5 − −
CaCl ₂ − − − − 0.5 1
――――――――――――――――――――――――――――――――――――
viscosity 14300 18000 20000 20000 20000 1000
−――――――――――――――――――――――――――――――――――――

As can be seen from Table 3, in the iota-type carrageenan + AA-2G blending system, the viscosity could be increased by adding NaCl. Moreover, the obtained gel had excellent usability and stability. The same effect was obtained with an alkaline agent such as NaOH or KOH instead of NaCl.
On the other hand, when CaCl ₂ was used instead of NaCl, the viscosity could be increased, but when the amount was too large, the viscosity was remarkably lowered, the range of the amount was very narrow, and the usability was poor.
Such an increase in viscosity is considered to be due to the influence of cations contained in the salt.
Therefore, in this invention, it is suitable to mix | blend the neutral salt and alkali containing a monovalent cation further, and the compounding quantity is 0.1-10 times with respect to the carrageenan mass, Furthermore, 0.2- It is preferable to make it 2 times.

Formulation Example 1 Gel (1) Iota Carrageenan 1
(2) Ion exchange water to 100
(3) Glycerin 2
(4) Dipropylene glycol 5
(5) PEG1000 1
(6) NaCl 1
(7) Citric acid 0.01
(8) Na citrate 0.09
(9) EDTA-3Na · 2H ₂ O 0.1
(10) Ascorbic acid 2-glucoside 2
(11) KOH 0.385
(12) Methylparaben 0.15
(13) Ethanol 5
(14) POE-POP decyl tetradecyl ether 0.2

(Manufacturing method)
The components (1) to (9) were mixed and heated to 80 ° C. to prepare aqueous phase parts. Thereafter, the chemicals (10) and (11) and alkali were added to the aqueous phase parts. This was cooled to 40 ° C., and ethanol parts mixed with (12) to (14) were added.
The gel of Formulation Example 1 was transparent and the viscosity was 23300 mPa · s / 30 ° C. When applied to the skin, it was fresh and stretched, and the storage stability was also good.

Formulation Example 2 Gel (1) Ion-exchanged water to 100
(2) Iota carrageenan 1
(3) Glycerin 2
(4) Dipropylene glycol 5
(5) PEG1000 1
(6) NaCl 1
(7) Citric acid 0.01
(8) Na citrate 0.09
(9) EDTA-3Na · 2H ₂ O 0.1
(10) Potassium 4-methoxysalicylate 3
(11) Ethanol 5
(12) Methylparaben 0.15
(13) POE-POP decyl tetradecyl ether 0.2

(Manufacturing method)
It adjusted according to the compounding example 1.
The gel of Formulation Example 2 was transparent and the viscosity was 11800 mPa · s / 30 ° C. When applied to the skin, it was fresh and stretched, and the storage stability was also good.

Formulation Example 3 Essence (1) Ion-exchanged water to 100
(2) Iota carrageenan 0.5
(3) Glycerin 2
(4) Dipropylene glycol 5
(5) PEG1000 1
(6) NaCl 1
(7) EDTA-3Na · 2H ₂ O 0.1
(8) Citric acid 0.01
(9) Na citrate 0.09
(10) Ascorbic acid 2-glucoside 2
(11) KOH 0.385
(12) Ethanol 5
(13) Methylparaben 0.15
(14) POE-POP decyl tetradecyl ether 0.2

(Manufacturing method)
It adjusted according to the compounding example 1.
The essence of Formulation Example 3 was transparent and the viscosity was 5700 mPa · s / 30 ° C. When applied to the skin, it was fresh and stretched, and the storage stability was also good.

Formulation Example 4 Emulsion (1) Ion-exchanged water to 100
(2) Iota carrageenan 1
(3) Glycerin 2
(4) KCl 0.375
(5) Citric acid 0.01
(6) Na citrate 0.09
(7) HEDTA-3Na 0.02
(8) Ascorbic acid 2-glucoside 2
(9) KOH 0.385
(10) Dimorpholinopyridazinone 0.05
(11) Phenoxyethanol 0.15
(12) Ethanol 5
(13) Dipropylene glycol 5
(14) POE (60) hardened castor oil 0.35
(15) Polyglyceryl diisostearate 0.2
(16) Glyceryl tri-2-ethylhexanoate 0.7
(17) Perfume appropriate amount

(Manufacturing method)
Water-soluble components (1) to (7) were mixed and heated to 80 ° C. to prepare aqueous phase parts. Thereafter, the chemicals and alkalis (8) to (9) were added at 70 ° C. This was cooled to 40 degreeC and the emulsification part which mixed (10)-(17) at 70 degreeC was added.
The emulsion of Formulation Example 4 had a viscosity of 14600 mPa · s / 30 ° C. When applied to the skin, it was fresh and stretched, and the storage stability was also good.

Claims (4)

A skin-type whitening agent selected from ascorbic acid compounds and / or alkoxysalicylic acid compounds and carrageenan, and having a viscosity of 2,000 to 30,000 mPa · s (30 ° C.) Agent. The skin external preparation according to claim 1, wherein the carrageenan is iota type. The external preparation for skin according to claim 1 or 2, further comprising one or more selected from neutral salts or alkalis containing monovalent cations in the composition, wherein the amount of neutral salt or alkali relative to the amount of carrageenan. An external preparation for skin having a mass of 0.1 to 10 times. The skin external preparation according to claim 3, wherein the neutral salt is sodium chloride and potassium chloride, and the alkali is sodium hydroxide and potassium hydroxide.