JPH0575721B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lotion that is stable against contamination with microorganisms. More specifically, one or more N-long-chain acyl basic amino acid derivatives represented by the general formula () or () and acid addition salts thereof, and a paraoxybenzoic acid ester represented by the general formula (). The present invention relates to a lotion containing a specific amount of one or more of these and having excellent microbial stability, which is characterized in that it does not substantially contain ethanol. Conventionally, as preservatives and antifungal agents for lotions, from among those listed in the Cosmetic Raw Materials Standards (hereinafter referred to as cosmetic ingredients), we have selected agents that are stable in lotions, do not have an adverse effect on the lotion itself, and are effective in small amounts. It is customary to use one type or a combination of two or more types with a strong strength. However, the reality is that there are restrictions on the composition of cosmetic bases, and from the standpoint of skin safety, it is not possible to incorporate them in large enough quantities to ensure a sufficient antiseptic and antifungal effect. Also,
There are many cases in which the constituent components of lotion and the preservative and antifungal agent interact with each other and lose their effectiveness. for example,
In lotions containing polymer mucilage, the effects of oil-soluble preservatives and fungicides such as paraoxybenzoic acid esters, sorbitan acid, and isopropyl methyl phenol are weakened due to adsorption, and their original antibacterial properties are often not exhibited. If a large amount is added with the expectation of further effects, another problem will arise: crystal precipitation at low temperatures. Also benzoate, dehydroacetate,
And salts such as salicylates are used in lotions.
It is well known that it is not effective unless the PH is weakly acidic, it becomes completely ineffective when it becomes basic, and as the acidity becomes stronger, the solubility in water decreases and crystallization occurs. Furthermore, even if cationic benzalkonium chloride and hibitene digluconate are fully effective, there are problems with skin safety and eyelid irritation, and they also tend to foam and become less effective in acidic conditions. It is a preservative and fungicide that is not suitable for the highly safe lotion that we aim for. Furthermore, since it reacts with anionic substances and is deactivated, its range of use is extremely limited. In particular, when the ethanol concentration in the lotion is in the range of 0 to 8% by weight, the antibacterial properties of ethanol cannot be expected to be very high, and since the lotion contains a lot of water, it is difficult to add preservatives and fungicides.
There are many problems with dissolution. Therefore, by using one or a combination of two or more of the preservatives and fungicides that are currently permitted for cosmetics, it is stable in lotions and does not have a negative effect on the lotions themselves, and is safe and effective. It is very difficult to obtain a strong preservative and antifungal agent, and even if many combinations are tested for each lotion, it is not possible to select an appropriate preservative and antifungal agent.
Furthermore, even if it were possible to select an appropriate preservative and fungicide, a great deal of time and effort would have to be spent to select it, which was a source of trouble for those skilled in the art. Furthermore, in the case of lotion, since it is required to have a certain level of transparency or more, it is not possible to use substances that cause the transparency to deteriorate over time and become cloudy or develop color, so cosmetics other than lotion cannot be used. It has been even more difficult to develop a substance that has sufficient antiseptic and antifungal effects compared to raw materials. Due to the above-mentioned circumstances, attempts are often made to incorporate newly developed antibacterial substances that are not listed in cosmetics, but contrary to the effects shown in aqueous solutions of these drugs, they show almost no effect in lotions. It is also true that many of these methods are rarely put into practical use, and the current situation is that the expectations of those skilled in the art are not met. For example, N-long-chain acyl basic amino acid derivatives represented by the general formula () or () and their acid addition salts have been disclosed as bactericidal detergents (Japanese Patent Publication No. 51-5413), and the () formula N-cocoyl-L-arginine ethyl ester-DL-pyrrolidone carboxylic acid salt corresponding to the acid addition salt of
It is also commercially available as a cationic surfactant with antibacterial properties (trade name: CAE; manufactured by Ajinomoto Co., Inc.).
CAE, which is in the form of pyrrolidone carboxylate, has good solubility in water.
It dissolves at a level of several percent by weight and is expected to find applications. However, in complex systems such as liquid cosmetics, where many types of raw materials are mixed or dissolved, the expected solubility cannot be achieved due to the influence of other solutes, so even if blended, However, there are many cases where no effect is shown. We synthesized N-long-chain acyl basic amino acid derivatives represented by the general formula () or () and their acid addition salts, and tried incorporating them into several types of liquid cosmetics, but the expected effects were not obtained. It has been confirmed that if the amount is increased to a level where the effect is not achieved and the cosmetic effect is achieved, the cosmetic itself becomes unstable, and there are very few liquid cosmetics that can satisfy both effects and stability. In particular, in systems that do not contain ethanol, we could hardly find a range that satisfies both efficacy and stability. In view of the above circumstances, the inventors of the present invention conducted extensive research in order to obtain a highly effective preservative and antifungal agent that is stable in lotion, does not adversely affect the product quality of lotion, and has excellent safety. As a result, the above N〓
- It has been found that the above object can be achieved by using a combination of a long-chain acyl basic amino acid derivative, an acid addition salt thereof, and a paraoxybenzoic acid ester, and the present invention has been completed. That is, the present invention provides 0.005% by weight<x≦0.05% by weight of one or more types (x) of the N-long-chain acyl basic amino acid derivatives and acid addition salts thereof represented by the following general formula () or (). % and 0.01% by weight of one or more paraoxybenzoic acid esters (y) represented by the following general formula () <y≦
This lotion contains 0.08% by weight of ethanol and is characterized by being substantially free of ethanol.

【formula】

[Formula] (However, in the formula, RCO has 6 to 6 carbon atoms.
20 saturated or unsaturated fatty acid residues, X is _-NH2 , -
OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ or -
It represents OCH ₂ C ₆ H ₅ , where n represents 3 or 4. )

[Formula] (In the formula, R is -CH ₃ , -C ₂ H ₅ , -
_It shows _{C3H7 , -C4H9 , -C6H5 , -CH2C6H5 .} ) According to the present invention, the preservative and antifungal agent is stable in lotion, does not cause crystal precipitation or precipitation even when left at low temperatures, and exhibits a strong inhibitory effect on all microorganisms such as mold, yeast, and bacteria. When used in combination, sufficient effects can be achieved with a smaller amount than when used alone. Next, the configuration of the present invention will be described. As the N〓-long chain acyl basic amino acid derivatives and their acid addition salts represented by the general formula () or () used in the present invention, N〓-caproyl-
L-arginine methyl ester hydrochloric acid, N-lauroyl-L-arginine ethyl ester-DL
-pyrrolidone carboxylate, N〓-palmitoyl-L-arginine ethyl ester hydrochloride acid, N〓-
cocoyl-L-lysine ethyl ester hydrochloride acid,
Examples include N-cocoyl-L-arginine ethyl ester-DL-pyrrolidonecarboxylic acid hydrochloride. In carrying out the present invention, one or more of these may be blended. The compounding amount (x) is
0.005% by weight<x≦0.05% by weight. If it is less than 0.005% by weight, sufficient antiseptic and antifungal effect cannot be obtained;
If the amount exceeds % by weight, the stability and transparency of the system are likely to be impaired. The paraoxybenzoic acid esters (hereinafter abbreviated as parabens) represented by the general formula () used in the present invention include paraoxybenzoic acid methyl esters, such as methylparaben, ethylparaben, propylparaben, n-butylparaben, isobutylparaben, and benzylparaben. Examples include parabens, and one or more of these may be blended. Blend amount
(y) is 0.01% by weight<y≦0.08% by weight. If it is less than 0.01% by weight, sufficient antiseptic and antifungal effect cannot be obtained.
When used in an amount exceeding 0.08% by weight, the transparency and stability of the lotion may be impaired. In addition to the above-mentioned essential ingredients, the lotion of the present invention includes:
Bases normally used in lotions, such as oil, surfactants, water, humectants, antioxidants, ultraviolet absorbers, other preservatives, fragrances, pigments, etc., are added as necessary. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples, the blending amount represents weight %. Prior to Examples, methods for evaluating antiseptic and antifungal effects and stability over time will be explained. (1) Evaluation of preservative and antifungal effect After inoculating 105 mold spores, ¹⁰⁵ yeast spores precultured for 48 hours, and ¹⁰⁶ bacteria precultured 24 hours per gram of cosmetics, The number of residual microorganisms was confirmed by culturing and evaluated in the following three stages. 〇Inoculated mold decreased to less than 100/g in 2 weeks Inoculated yeast decreased to less than 100/g in 1 week Inoculated bacteria decreased to less than 100/g in 1 week △Inoculated mold decreased to 100/g in 3 weeks Inoculated yeast decreased to 100/g or less in 2 weeks Inoculated bacteria decreased to 100/g or less in 2 weeks × Inoculated mold, yeast, and bacteria did not reach the level of △ above 〇 Evaluations of △ and △ are based on cases where all the conditions for mold, yeast, and bacteria are satisfied; if even one type of microorganism does not satisfy these conditions, the evaluation is evaluated as ×. (2) Temperature stability of lotion over time The lotion in a glass bottle was heated to 37°C and 0°C.
Changes in appearance after being left for a week were observed and evaluated on the following two scales. 〇: No precipitation observed ×: Precipitation occurred Examples 1 and 2, Comparative Examples 1 to 5

[Table] (Production method) Add and dissolve at room temperature (water part). Add and dissolve at 50℃ (glycol part). The glycol part was added to the water part, mixed, solubilized, colored with a pigment, and then filtered to obtain a lotion. (Results) As is clear from Table 1, the examples of the present invention had good antiseptic and antifungal effects and stability over time.

Claims (1)

[Scope of Claims] 1 N-long chain acyl basic amino acid derivatives represented by the general formula () or () and one or more of the acid addition salts thereof (x) in an amount of 0.005% by weight < x
≦0.05% by weight, and one or more paraoxybenzoic acid esters represented by the general formula () (y)
0.01% by weight<y≦0.08% by weight, and is characterized by substantially not containing ethanol. [Formula] [Formula] (However, in the formula, RCO has 6 or more carbon atoms.
20 saturated or unsaturated fatty acid residues, X is _-NH2 , -
OCH ₃ , -OC ₂ H ₅ , -OC ₃ H ₇ , -OC ₄ H ₉ or -
It represents OCH ₂ C ₆ H ₅ , where n represents 3 or 4. ) [Formula] (In the formula, R is -CH ₃ , -C ₂ H ₅ , -
_It shows _{C3H7 , -C4H9 , -C6H5 , -CH2C6H5 .} )