JPH03148208A - External preparation for skin - Google Patents

Abstract

PURPOSE:To obtain the subject external preparation for skin capable of showing its antibacterial effect in a small amount of an antibacterial agent and excellent in safety to the skin, stability and functionality by blending a synthetic bentonite, a silicone oil and the antibacterial agent. CONSTITUTION:With 0.1-5.0wt.% synthetic bentonite, preferably lithium magnesium silicate, 2-30wt.% silicone oil (e.g. dimethylpolysiloxane or methylphenylpolysiloxane) and 0.005-5wt.% one or more antibacterial agents preferably selected from a group of hinokitiol, photosensitizer 201, abietic acid, rosin and resorcin are blended. Further addition of 0.1-5.0wt.% fatty acid monoglyceride thereto raises the viscosity and provides an oily touch and an excellent stability and functionality difficult to obtain by analogous raw materials.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a skin external preparation having antibacterial activity.

In more detail, it is formulated with a small amount of antibacterial agent to demonstrate antibacterial power,
This invention relates to an external skin preparation that is excellent in terms of safety, stability, and sensory aspects for the skin.

[Conventional technology]

Cosmetics and pharmaceuticals include various preparations containing antibacterial agents.

And its dosage forms vary. Among these dosage forms, cream-like and milky-like forms have the best organoleptic sensation and feeling of use.

However, when a surfactant is added to create such an emulsion type product, the effectiveness of many antibacterial agents decreases in creams containing surfactants, and the amount of antibacterial agent must be increased. However, there were problems in terms of safety and efficacy.

Surfactants are also not sufficiently safe for the skin.

Therefore, various studies are being conducted on emulsification methods that do not use surfactants. One known method is an emulsification method using synthetic bentonite. Bentonite is a special colloidal clay that occurs naturally, and is mainly composed of montmorillonite. Natural products have many impurities and do not form strong gels, but when the type of metal is changed to improve the purity and use whitened magnesium silicate, lithium, or synthetic bentonite, the gel has high thixotropy and can be incorporated into cosmetics. It can be used as

JP-A No. 60-178.803 describes basic cosmetics using lithium-montmorillonite water-swollen gel as the water base for basic cosmetic creams, but the use of bentonite in basic cosmetics has never been done before. Since this publication is well known, it is believed that this publication uses a lithium-montmorillonite water-swellable gel body and a plant protein to disperse setsubun into water.

As described above, synthetic bentonite is widely used in cosmetics as a gelling agent, but when an emulsion is formed using only synthetic bentonite without adding a surfactant, the particles of the emulsion are coarse and tend to solidify over time. However, it also had a squeaky feel in terms of organoleptic aspects, and could not be used as a product.

On the other hand, silicone oil is also widely used as a cosmetic, but silicone oil is considered to be a substance that is difficult to emulsify and is used as an antifoaming agent.

There have been no examples of silicone oil being used in combination with synthetic bentonite, and it was customary to use it at less than 2%.

Although various attempts have been made to create cosmetics that do not contain surfactants, none of them have been able to be used as actual products.

This method of emulsifying cosmetics without using surfactants is
Although it is not impossible to create conventional emulsified cosmetics without using surfactants, in order to use them as products, they must have fine texture, stability, and sensuality such as squeaky feel. , cream-like physical properties, etc. are insufficient, and satisfactory results have not been obtained.

[Problem to be solved by the invention]

The object of the present invention is to provide an emulsified skin preparation containing an antibacterial agent without reducing the effect of the antibacterial agent, and thus retaining antibacterial activity with a small amount of antibacterial agent. The emulsion is stable without the use of surfactants, has a fine texture, does not cause discomfort when used such as a squeak, has excellent physical properties as a cream, etc., and is safe for the skin. The purpose of the present invention is to provide an antibacterial agent-containing external skin preparation that is guaranteed to be safe.

Furthermore, there are topical skin preparations for treating acne that contain antibacterial agents, but in this case, it is better to contain as little oil as possible, and a light feel is preferred from a sensory standpoint. To provide an external preparation for skin containing an antibacterial agent that is less sensitive.

[Means to solve the problem]

The present inventors conducted extensive research to solve the above problems.

The most effective means for preserving the antibacterial activity of antibacterial agents is not to use surfactants. Therefore, we have investigated many substances that can be used as external preparations for the skin regarding emulsification methods that do not use surfactants.
I couldn't reach a decision.

Therefore, we ignored the amounts normally used in external skin preparations and re-experimented by taking into account quantitative changes, and discovered that we could solve the above problems at once by using a large amount of silicone oil together with synthetic bentonite. Completed the invention.

That is, the present invention is an external preparation for skin that contains at least synthetic bentonite, silicone oil, and an antibacterial agent.

It is preferable to contain 0.1 to 5.0% by weight of synthetic bentonite and 2 to 30% by weight of silicone oil.

Furthermore, it is preferable to contain 0.1 to 5.0% by weight of fatty acid monoglyceride.

As the antibacterial agent, it is preferable to use at least one selected from the group consisting of hinokitiol, photosensor No. 201, abietic acid, rosin, and resorcinol.

In the present invention, since no surfactant is blended, the ability of the antibacterial agent is maximized and the amount of antibacterial agent is reduced.
Therefore, safety and effectiveness can be improved in this aspect as well.

In addition, synthetic bentonite and silicone extracts have a functional surface and meet the purpose of the present invention.

As the synthetic bentonite, it is preferable to use the above-mentioned magnesium silicate and lithium.

The silicone oil may be any raw material commonly called silicone oil such as dimethylpolysiloxane or methylphenylpolysiloxane, and the degree of polymerization, that is, the viscosity, is not particularly limited and can be selected depending on the combination with other raw materials and the purpose of the finished product. do it.

Furthermore, it is not easy to disperse synthetic bentonite, but it can be easily uniformized by using a microfluidizer.

Furthermore, when emulsifying, the same effect can be obtained even if the entire skin external preparation is emulsified through a microfluidizer. Emulsification using a microfluidizer increases gel strength, requires less synthetic bentonite, and provides superior results not only from a cost perspective but also from a skin sensory perspective.

Since no surfactant is used in the emulsification of the skin external preparation of the present invention, physically making the particles finer is also a major factor, so by using a microfluidizer,
Of course, it is better to have strong emulsifying power.

By incorporating silicone into the skin external preparation of the present invention, the particles become fine and a thickening effect is produced, and the amount of synthetic bentonite to be incorporated can be reduced.

As a result, in addition to the spreadability that Siliconura has, the reduction in the amount of synthetic bentonite blended with the same substance reduces the sticky feeling, and the viscosity mechanism incorporates elements other than gel, and the fineness of the particles. The stability is improved by
Moreover, the physical properties are also improved.

In addition, when fatty acid monoglyceride is added, the viscosity increases, and it also gives a feeling of freshness in terms of sensory aspects, providing stability and functionality that cannot be obtained with other similar raw materials, and its effectiveness is high. Any fatty acid having a carbon number of 12 to 22 can be used.

The amount of synthetic bentonite blended is affected by other raw materials, emulsification method, and dispersion method, but it is 0.1 to 5% of the total external preparation.
．． 0% by weight is preferred. If it is less than 0.1% by weight, emulsification will be insufficient, and if it exceeds 5.0% by weight, it will give a strong squeaky feeling when used on the skin, which is not preferable.

The amount of silicone oil blended is preferably 2 to 30% by weight based on the total external preparation. If it is less than 2% by weight, no sensory improvement is observed and no improvement in emulsification is observed. If it exceeds 30% by weight, emulsification with the aqueous phase becomes difficult again and the oily feeling becomes strong, which is not preferable.

As the antibacterial agent used in the external skin preparation of the present invention, hinokitiol, photosensor No. 201, resorcinol, etc., which are antibacterial agents usually used in external skin preparations, can be used. One cause of acne, a skin disease, is thought to be related to bacteria within hair follicles, and creams and ointments containing antibacterial agents are used. The applicant has discovered that abietic acid and rosin containing it are effective as antibacterial agents in external skin preparations for acne treatment, and are highly safe and stable without side effects or sensitization, and have filed a separate application. are doing.

When this abietic acid or a rosin containing it is used as an antibacterial agent in the skin external preparation of the present invention, a stable emulsion can be obtained without inhibiting antibacterial activity, and the propagation
ionibacterium acnes.

5taphylococcus aureus, 5t
aphylococcus eojdermi-dis
It is effective against bacteria in hair follicles such as. The amount of antibacterial agent used varies greatly depending on the type of antibacterial agent, but is in the range of 0.005 to 5% by weight based on the total external preparation.

Synthetic pen!・There are no particular restrictions on raw materials other than night and silicon extraction, and liquid oils include liquid paraffin, squalane, olive ura, jojoba oil, safflower oil,
Mink oil, myristyl myristate, triglyceride, etc. are included, and solid oils include paraffin, ceresin, beeswax, gay wax, fatty acids, higher alcohols, etc. Other additives, fragrances, preservatives, antioxidants, etc. can be added. .

These raw materials are selected depending on the purpose, but the quantitative ratio of the compatriots is
Since it affects the physical properties of the product, its amount should be adjusted according to the purpose.

Furthermore, when used as an external skin preparation for treating acne, it is of course better to use less oil.

Since aqueous raw materials change the gel strength of synthetic bentonite, their formulation affects the physical properties of the product.

First, polyhydric alcohols are listed in descending order of gel strength: glycerin, 1,3-butylene glycol, and PEG100O.

Optimal conditions are selected by using these alone or in combination of two or more depending on the amount and purpose of use of the product.

In addition, gel formation is affected by the concentration of the electrolyte, and the optimum conditions differ depending on the type of ion, so if the type and amount of ions are selected, the amount of synthetic bentonite used can be reduced.

Although the addition of an electrolyte exhibits the above-mentioned effects, it does not directly affect the effects of the present invention, so its addition is not essential, but it is preferable to add it because it allows the amount of synthetic bentonite to be reduced. .

In the examples, methyl paraoxybenzoate is used as a preservative to play the role of an electrolyte, but since a preservative is not necessarily required, other electrolytes may be used without the same problem.

Furthermore, if the pH is lower than 5.5, aggregation occurs, so a stable product cannot be obtained at a pH lower than this.

However, synthetic bentonite has a pH buffering effect, and when it is made into an aqueous solution, the pH is around 8.5, so there is no need to adjust the pH, especially when no raw materials that affect the pH are mixed.

Furthermore, some types of water-soluble polymers can destroy gels, and effective water-soluble polymers include, for example, carboxymethyl cellulose, polyvinyl alcohol, and the like.

Water-soluble additives also need to be blended with the above-mentioned precautions.

〔Example〕

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the same extent by these Examples. Unless otherwise specified, numerical values are based on weight (parts by weight, etc.).

(Example 1) IA of emollient cream Squalane 15.9 Glycerin monostearate 2.0 Behenyl alcohol 2.0 Dimethyl polysiloxane (100 cps) 10. 0 Rosin 0.1B Synthetic bentonite 1.0 Purified water 48.813 Butylene glycol 20. O Preservative (Methyl Baroxybenzoate) 0.2 After well dispersing synthetic bentonite in purified water, weigh A and B each, and approximately 7
Heat to 0°C, and while stirring B, gradually add A to emulsify, and cool to room temperature.

(Example 2) 2A of emollient cream Abietic acid 0.1 dimethyl polysiloxane (100 cps) 5. OB
Synthetic bentonite 2.
0 ice cubes 78.7
Glycerin 3.5 propylene glycol 7. 01
% Hibis Wako 105 aqueous solution 1.0 (N
aOH neutralized solution) C Placenta extract 2. O
D Fragrance 0.
5 After well dispersing the synthetic bentonite in purified water, A and B
Weigh each and heat to about 70°C. While stirring B, gradually add A. When the temperature reaches about 60°C, add C and D and cool to room temperature.

(Example 3) Emulsion A Squalane 1.
0 olive oil 1
802-Ethylhexanoic acid triglyceride 1.
0 cetanol 1.
0 beeswax 0.
5 methyl phenyl polysiloxane 2.0
Dimethylpolysiloxane (100cps) 3
．． 0 antioxidant 0
．． 2 Photosensitive element No. 201 0
．． 0 Lusorcin 0
．． IB synthetic bentonite
2. 0 purified water 7
4.49 Glycerin 8
,0 dipropylene glycol 5
．． 0 carboxymethylcellulose 0.
5 (1.0% aqueous solution) Preservative (methyl roseoxybenzoate) 0.2 After well dispersing the synthetic bentonite in purified water, weigh each of A and B, heat to about 70°C, and stir A. At the same time, gradually add B and cool to room temperature.

(Comparative Example 1) A cream in which the raw materials of Emollient Cream 1 of Example 1 were changed as follows.

A Squalane 22
．． 9 Glycerin monostearate
2.0 behenyl alcohol
2.0 dimethylpolysiloxane (100cps)
2. 0 Rosin Sorbitan Monostearate B Polyoxyethylene Sorbitan Monostearate (2
0E, O,) Purified water 1.3 Butylene glycol preservative (methyl roseoxybenzoate) (Comparative example 2) A cream obtained by changing the raw materials of the emollient cream 2 of Example 2 as follows.

A: Dimethyl abietate polysiloxane (100 cps) Sorbitan monostearate B: Polyoxyethylene hardened Castor (60E, 0.)
Purified water Glycerin Propylene glycol 1% Hibis Wako 105 aqueous solution (NaOH neutralized solution) Preservative i'FJ (Methyl roseoxybenzoate) Placenta extract D at 44°20°C Fragrance (Comparative example 3) The emulsion of Example 3 is as follows. Nogoto emulsion.

A Squalane Olive oil 2-Ethylhexanoic acid triglyceride Setanol Beeswax Methyl phenyl polysiloxane Dimethyl polysiloxane (100 cps) Sorbitan monostearate Antioxidant Photosensitizer No. 201 Resorcin B Polyoxyethylene Sorbitan monostearate (2
0E, 0. ) Polyoxyethylene hydrogenated castor oil (60E, O,) Purified water Toro 2゜4 Glycerin 8.0
dipropylene glycol
5. 0 Carboxymethylcellulose (1.0% aqueous solution) 10.5 Preservative (methyl hydroxybenzoate) 0.2
A preservative (methyl roseoxybenzoate) was removed from the above formulation to create a formulation containing the antibacterial agent at the following concentration.

Add Proplonibac to 20g of the emulsion you created.
terium acnes 1.0~1.5X107
The cells were inoculated individually and left at 37°C. 24 hours later, 1 week later,
After 2 and 3 weeks, a portion was taken out and the number of viable bacteria was determined. A modified CAM medium was used as the medium, and each operation was performed anaerobically.

N: No bacteria detected N: No bacteria detected N: No bacteria detected Usage test The method was tested using the double adventure method.

Presenter Na 1 to 16 are Example-1, Presenter No. 17
-32 is Comparative Example-1.

The criteria for effectiveness were as follows.

Acne condition Improvement degree Irritation or not
−Severe −−Worse −−No irritation +10
- Mild - No change 10 - Slight irritation + + 10 - Moderate 10 - Slight improvement 10 - Irritation + + 10 - Slightly severe 10 - Significant improvement ++ 10 - Considerable irritation + + + + - Severe 10 + Significant improvement [Safety test] (Method) (1) Cytotoxicity test 1) Place lEa in a chalet at 6 am with a cover glass.
glcMEM (fetal bovine serum 20%) medium
Dispense in ml.

2) Add JTC-17 cell suspension (300,000 cells) to 5%
Culture at CO, 36°C for 148 hours.

3) Buffer PBS (-) (NaCN 8 g.

KCN O, 2g, Na PO 1, 15g.

4) Wash twice with buffer containing 2 g of KHPOO) 4) Add 3 ml of sample diluted with buffer PBS(-) and incubate at 36°C for 60 minutes.

5) Eagle MELvf (20% fetal bovine serum)
Dispense the medium into 7 ml portions and store in 5% Co, at 36°C, 48°C.
Incubate for hours.

6) Fix, stain and judge.

Judgment criteria [1] Judgment based on cell number 5 cores O: Same 5 cores as Control
1: Almost the same as Control (slightly inferior staining density) Score 2: 2/3 of Control (decreased enough to be visible to the naked eye) Score 3: Almost half of Control (significantly decreased) Score 4: 1/1 of Control 3rd place (very few cells) Score 5: No cells observed (no or almost no cells observed) [2] Judgment based on cell morphology 5core O: Normal image 5core 1: Slight abnormal cells observed (normal cells 80% or more) Score 2: Abnormal cells are observed (normal cells are around 50% to 80%) Scorp 3: Many abnormal cells are observed (normal cells are around 20% to 5096th) Most of the cells are abnormal.

(Normal cells are approximately 10%) Scorp 5: Normal cells are not recognized The first number indicates the determination result based on the number of cells, and the number in parentheses indicates the determination result based on cell morphology.

(2) Human closed patch test 1) Apply the sample to the plaster (fin chamber),
Apply it on the inside of your upper arm and leave it for 24 hours.

2) Peel off the plaster and leave it for 1 hour.

(Iritisotropy) Judgment irritation point 0.00 No reaction 0.00 Suspicious erythema, slight erythema 0.50 Mild erythema, erythema, erythema, W tumor, erythema + edema papules, serous papules, small varicella 0 0 2 ° above + 0 3 ° + corp Stimulation rate - total stimulation points / total number of people x 100 (3) Rabbit closed batch test Six Japanese white rabbits were used. Trim the back skin with electric clippers and apply 0.2 of the sample to the veterinary patch test wound.
Add 1ml drop and apply it to the skin for 24 hours.

Judgment is made based on the following criteria at 1.24.48.72 hours after removal of the patch.

(Judgment criteria) Erythema 5core O: No erythema 5core 1: Very mild erythema (barely noticeable) Score 2: Obvious erythema 5core 3: Moderate to strong erythema 5core 4
: Strong crimson erythema with mild face skin formation (disorder is deep) Score Score 0: No edema 1: Very mild edema) (Finally recognized 5core 2: Obvious edema (clearly distinguishable from the surrounding area) Score 3 : Moderate edema (raised by about 1mm) Score 4 : Strong edema (raised by more than 1mm,
(4) Guinea pig continuous application test 1) Using 6 Hartley white guinea pigs, the skin on the back and flanks is removed with electric clippers and a shaver, and the skin is applied within a 2 cm diameter area with a cotton swab.

2) Apply this application once a day for 3 consecutive days.

(ill determined) (Judgment criteria) Erythema and edema are measured, but same as rabbit closed batch test.

Cumulative stimulation index was 72 after Itr, after 9BHr, after 16B
This is the average value of 5 cores after tlr.

(Results) 2) Human closed batch test 3) Rabbit closed patch test 4) Guinea pig continuous application test [Effects of the invention] In the skin external preparation of the present invention, it is possible to emulsify the antibacterial agent without reducing its effectiveness. By adding a small amount of antibacterial agent, it is possible to obtain an emulsified skin preparation that maintains antibacterial activity.

The skin external preparation of the present invention has a stable emulsion without the use of ordinary surfactants, has a fine texture, does not cause discomfort when used such as a squeaky feeling, and has good physical properties as a cream, emulsion, etc. It is excellent and is guaranteed to be safe for the skin.

As external skin preparations containing antibacterial agents, there are external skin preparations for acne treatment, but the skin external preparation of the present invention contains antibacterial agents with less oily feeling and can reduce the amount of shavings, giving a light feel on the sensory side. It is an external preparation for the skin.

Claims (1)

[Scope of Claims] 1. An external skin preparation comprising at least synthetic bentonite, silicone oil, and an antibacterial agent. 2. The external preparation for skin according to claim 1, which contains 0.1 to 5.0% by weight of synthetic bentonite. 3. Claim 1 containing 2 to 30% by weight of silicone oil
or the skin external preparation according to 2. 4. The skin external preparation according to any one of claims 1, 2 and 3, which contains 0.1 to 5.0% by weight of fatty acid monoglyceride. 5. Claims 1 and 2, wherein the antibacterial agent is at least one selected from the group consisting of hinokitiol, photosensor No. 201, abietic acid, rosin, and resorcinol.
The skin external preparation according to any one of , 3 and 4.