JPS63188610A - Cosmetic - Google Patents

Abstract

PURPOSE:To obtain a safe cosmetic having synergistically increased antimicrobial activity and sufficient antisepticizing power free from a feeling of skin irritation, by using specific amounts of 1,3-butylene glycol, a surface active agent having a specific ratio of inorganic properties and organic properties and an organic acid. CONSTITUTION:A cosmetic is blended with (A) 0.5-10wt.% calculated as antimicrobial component of a surface active agent such as monopalmitic acid sucrose ester, monomyristic acid decaglycerin, etc., having antimicrobial activity and a ratio of inorganic properties and organic properties of 1.20-2.00, (B) 0.05-0.5wt.% one or more organic acids, preferably citric acid, lactic acid, etc., as an antimicrobial component and (C) 3-20wt.% 1,3-butylene glycol to give a cosmetic having enhanced antimicrobial actions of the components A and B, showing sufficient antimicrobial activity without adding an antiseptic such as parahydroxybenzoic ester, etc., providing an unfavorable irritating feeling and high safety.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to the use of 1.3-butylene glycol in an amount of 3 to 20% by weight, a surfactant in which 1.0.8 is 1.20 to 2.00, and an organic The present invention relates to a safe cosmetic containing one or more acids, which has antiseptic properties and does not cause skin irritation.

[Conventional technology]

Conventionally, cosmetics have been formulated with preservatives or fragrances having a preservative effect as listed in Table 1 in order to prevent microbial contamination. Preservatives to be added to cosmetics must have a broad antibacterial spectrum, be effective in small amounts, be stable in formulations and not have their efficacy reduced by the influence of PL+ or other ingredients, and have solubility.

It has excellent dispersibility, does not interfere with the product's nine colors, odors, etc., is as harmless to living organisms as possible, is non-irritating, has no sensitization, phototoxicity, photosensitization, or mutagenicity, and is highly safe. etc., and preservatives that meet these requirements have been sought and studied. As a result, a wide variety of preservatives have been recognized as being usable in cosmetics, and among them, rose hydroxybenzoic acid esters are considered to be highly safe and are the most commonly used.

[Problem that the invention seeks to solve]

However, these preservatives, including rose hydroxybenzoic acid esters, have the problem of ``skin irritation,'' which has been largely ignored until now due to problems such as skin irritation and melasma caused by cosmetics. Ta. (Currently being submitted to the journal of the Japan Society of Cosmetic Technologists) This skin irritation is caused by the pain and itchiness felt when applied to the skin, even at the preservative concentration actually used, where no inflammatory irritation was observed in the human punch test. It causes unpleasant sensations such as ``burning'' and ``tingling,'' and, like inflammatory or sensitizing irritation, is a serious problem when using cosmetics. Table 1 shows the skin irritation caused by some preservatives.

Table 1. Skin irritation caused by preservative Preservative Concentration a) Skin irritation b) Eugenol 0.05 2.9a) Carboxymethyl cellulose (C, M, C) 1.0% aqueous solution weight % b) Applied to 30 subjects It is shown as the average value of the ratings when the feeling of stimulation is evaluated on the following four levels.

Evaluation: 0 Irritation No irritation 1 Somewhat painful 2 Painful 3 Very painful However, if we refrain from using these preservatives to suppress this skin irritation, the problem of microbial contamination of cosmetics will arise, so cosmetics should not be used. In addition to the need to consider the form of the material, it also requires aseptic manufacturing, which requires significant capital investment and strict control of the process.

[Means for solving problems]

In order to solve the above problems, we conducted various studies and found that adding 1,3-butylene glycol can improve the preservative power of the system (
US Patent 37321)2. British patent 1409024°K
, 8cott et al.; J. Food Sci.
, 41 (31541-546 (1976)). Also,
In addition to conventional preservatives, it has been found that there are surfactants and organic acids that have antibacterial activity (Nobuyuki Kato et al.; Antibacterial and Antifungal 3 (sl 355-361 (1975); Takeshi Uchibori; Surface 21). (4t 182-193 (1983),
Sanitation Technology Society; Food preservation technology using natural products pp, 5
-1) (1981)). When these are used in combination, practical antibacterial activity can be expected due to the additive effect of the individual antibacterial activities.

From the results of our study, we considered that 1,3-butylene glycol has the effect of enhancing the antibacterial effects of other substances, and that organic acids act antibacterially by lowering the pH due to the addition of 1,3-butylene glycol. For surfactants with antimicrobial activity, the inorganic-to-organic ratio (Inor-ganic-Org
anic balance, 1. This could be explained using O, B). That is, in order for a certain substance to have antibacterial activity, the substance must be hydrophilic to some extent and an effective amount must be transferred to the aqueous phase and come into contact with microorganisms in the aqueous phase. On the other hand, in order for a substance that has come into contact with a microorganism to permeate the cell membrane of the microorganism and exhibit antibacterial activity, a certain degree of lipophilicity is required. In other words, it is necessary to have both hydrophilicity and lipophilicity. These properties were expressed using an organic conceptual diagram. An organic conceptual diagram is an attempt to systematically summarize the properties of organic compounds under one theory, and is systematically assembled based on some basic physical properties of organic compounds.

In addition to individual physical property values, it is also possible to predict the general outline of a wide range of compounds from a certain degree of chemical structure, based on the origin of the properties (determining a certain standard as a numerical value, and then This paper aims to help conceptually understand all organic compounds by considering a method of showing the compounds of Inor
ganic-organic balance, 1.0
．． B) is used. ! , 0.8 is simply the ratio of the inorganic part to the organic part in the structure of an organic compound. In the present invention, surfactants I which serve our purposes.

0.8 was in the range of 1.20-2.00.

The blending amount of the surfactant with 1.0.8 of 1.20 to 2.00 is 0.5 to 10% by weight, considering the amount that is effective for expressing antibacterial activity and does not cause irritation. did.

The amount of organic acid blended was 0.05 to 0.5% by weight, which does not cause skin irritation. Regarding 1,3-butylene glycol, it was decided to incorporate 3 to 20% by weight in consideration of the effective amount and feeling of use.

1. As the surfactant having O and B of 1.20 to 2.00, sucrose monopalmitate, decaglyceryl monomyristate, etc. are used. Furthermore, as the organic acid, citric acid and lactic acid give preferable results.

[Action and effect]

The functions and effects of the present invention will be explained in detail with reference to Examples.

(Example 1) Cleansing cream The prescription is shown below along with comparative examples.

After mixing ① to ② and heating and dissolving at 85 to 90°C, 0 to [phases] and ①, which were mixed and heated in the same manner, are added and emulsified.
After emulsification, cool while stirring, and add ① at 45°C.

(Example 2) lotion The prescription is shown below along with comparative examples.

Mix and dissolve ■～■. When adding (2), heat and dissolve part of (2) in advance, cool and mix.

Examples 1 and 2 above. Comparative Examples 1 to 4 were examined for skin irritation and antibacterial activity.

Regarding the sensation of skin irritation, 30 subjects used the cosmetics of Examples and Comparative Examples and evaluated the sensation of irritation on a four-point scale as follows.

Evaluation Sensation of irritation 0 No irritation 1 Slightly painful 2 Painful 3 Very painful The results are shown as the number (percentage) of subjects who gave ratings of O to 3 for each sample, and are summarized in Table 2.

Antibacterial activity was determined by Escherichia coli (Escherichia coli).
l i).

Green MiA seedling (Pseudomonas aerugi)
nosa), Pseudomonas cepasia (Pseu
domonas eμμ flies).

Staphylococcus aureus (Staphylococcus a)
ureus) were cultured individually and then mixed, sample 20
The bacteria were inoculated to approximately 5.0 x 10 cells/g in a well.

After inoculation, the samples were allowed to stand at 37°C, and the number of viable bacteria per gram of each sample after 2 weeks is shown in Table 3.

Table 2. Skin irritation table 3. Antibacterial activity Table 22 From Table 3, cosmetics using preservatives (methyl and propyl parahydroxybenzoate), namely Comparative Example 1
．． In Comparative Example 3, the antibacterial activity was sufficiently satisfactory as the test bacteria were killed two weeks after inoculation, but it was shown that good results were not obtained regarding skin irritation. In other words, 80% of the subjects in Comparative Example 1 and 60% of the subjects in Comparative Example 3
complains of some kind of skin irritation.

Regarding Comparative Example 2 and Comparative Example 4, the former was subject 1.
0% answered that it was somewhat irritating, and no one in the latter group complained of irritating sensation (Table 2), but as shown in Table 3,
Even after 2 weeks after inoculation, many viable bacteria were observed (8
X10' cells/g, lXl0' cells/g), and no antibacterial activity was observed.

Regarding Examples 1 and 2, only 3% of the test subjects in the former complained of slight irritation (Table 2), and the antibacterial activity also showed that the test bacteria died two weeks after inoculation. (Table 3) and was sufficient. That is, the examples of the present invention were highly safe cosmetics that had sufficient antibacterial activity and hardly caused skin irritation.

As described above, the present invention makes it possible to provide cosmetics with sufficient antibacterial activity and high safety without the need to incorporate preservatives that cause undesirable skin irritation upon use. Ta.

Claims (3)

[Claims] (1) 3 to 20% by weight of 1,3-butylene glycol;
Inorganic-Organic Ratio
c balance, I. O. B) is 1.20 to 2.0
A cosmetic containing 0 surfactant and one or more organic acids. (2) I. O. The cosmetic according to claim 1, wherein the amount of the surfactant having B of 1.20 to 2.00 is 0.5 to 10% by weight. (3) The cosmetic according to claim 1 or 2, wherein the amount of organic acid blended is 0.05 to 0.5% by weight.