JPS63126542A - Microemulsion - Google Patents

Abstract

PURPOSE:To enhance the temp. stability of the title microemulsion by mixing specified amts. of a hydrophilic ionic surfactant, plural kinds of oil having a specified inorg. property on the org. conceptual chart and contg. a specified number of carbons, and water to prepare the microemulsion. CONSTITUTION:The hydrophilic ionic surfactant, one or >=2 kinds among the >=15C oil having 0 inorg. property on the org. conceptual chart, the >=16C oil at 2<inorg. property <=20, the >=17C oil at 20<inorg. property <=50, the >=18C oil at 50<inorg. property <=100, the >=19C oil at 100<inorg. property <=150, the >=20C oil at 150<inorg. property <=200, the >=21C oil at 200<inorg. property <=250, and the >=22C oil at 250<inorg. property, and water are mixed. A microemulsion contg. 0.005-60wt.% of the above-mentioned oil, contg. a 1/0.5-1/10 ratio of the hydrophilic ionic surfactant and the total oil component, and having 0.01-0.1mum mean particle diameter is thus obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a microemulsion that uses a hydrophilic ionic surfactant and can stably contain a large amount of oil over a wide temperature range. , used in fields such as cosmetics.

[Prior Art] Conventionally known microemulsions are as follows. That is, the first is obtained using a conventional nonionic surfactant and oil, the second is a combination of an anionic surfactant and a cosurfactant, and the third is a combination of an anionic surfactant and a nonionic surfactant. It uses a combination of a surfactant or an electrolyte.

The first is that when a hydrocarbon such as cyclohexane or n-heptane is added to an aqueous solution of a nonionic surfactant such as +5o-RCHO(CH2CHzO)9H and the temperature is raised, the concentration of the nonionic surfactant increases. In front of this, a region appears where the amount of solubilized hydrocarbons (oil) increases rapidly (Kozo Shinoda, 209-225, Solution and Solubility, round neck). From the solubilization limit temperature shown in the phase diagram to the agreement! It is known that in the W region, the solubility of oil in the aqueous phase increases dramatically, forming a so-called microemulsion. However, microemulsions (1w region) with increased oil solubilization obtained with nonionic surfactant-hydrocarbon systems that have been studied previously have maintained the hydrophilic-lipophilic balance of the system. It exists only in a very narrow temperature range (about several degrees Celsius to about 10 degrees Celsius), and has the disadvantage that outside this range, the system becomes cloudy immediately or over time, and eventually separates into water and oil. For this reason, it is extremely difficult to apply it to cosmetics or pharmaceuticals.

The second method is to balance the hydrophilic-lipophilic balance of the system by combining an anionic surfactant and co-surfactants such as pentanol, hexanol, and octatool. The aim is to utilize the region where the amount of solubilization increases rapidly. The third is
By adding an electrolyte to a combination of a lipophilic nonionic surfactant and a specific anionic surfactant, or a combination of a lipophilic nonionic surfactant and an ionic surfactant, a hydrophilic-philic system can be selected from among the compositions. It attempts to utilize the region where the amount of solubilized hydrocarbons (oil) increases rapidly within a very narrow ratio range where the oil balance is balanced (Kozo Shinoda, Hiroyuki Saijo, 308-314.35.1986 , JP-A-58-1
28311, Japanese Unexamined Patent Publication No. 58-131127”).Second,
In the third method, stability against temperature has been solved, but the composition in which the microemulsion can stably exist is still very limited, and in actual product systems, the formulation is quite limited or complicated. There are concerns that it will become Furthermore, the second method uses a cosurfactant such as hexanol, which poses a safety problem.

[Problems to be solved by the invention] For this reason, makeup 'F4 intended for use at normal temperatures.
The use of microemulsions in medicines and medicines is the first
The method 1 was considered difficult from the viewpoint of stability, and the methods 2 and 8 were viewed as problematic from the viewpoint of prescription. However, the ability of microemulsions to uniformly dissolve a large amount of oil with a small amount of surfactant is extremely useful, and creating microemulsions with high temperature stability and a wide range of formulations is a challenge for researchers. was.

In view of this current situation, the present researchers conducted intensive research in order to obtain microemulsions with excellent temperature stability and a wide range of formulations. Surprisingly, by using a combination of oils with limited inorganic properties (Organic Concept Diagram, Yoshio Koda, Sankyo Publishing, 1984), it is possible to easily form microemulsions that are stable over a very wide temperature range. They have found that the present invention can be obtained, and have completed the desired invention.

[Means for solving the problems] That is, the present invention provides a hydrophilic ionic surfactant;
Oil with an inorganicity of 0 on the organic concept diagram and a carbon number of 15 or more, 0, an oil with an inorganicity of ≦20 and a carbon number of 16 or more, 20
Oils with inorganic properties ≦50 and carbon numbers of 17 or more, oils with 50<inorganic properties≦100 and carbon numbers of 18 or more, oils with 100 inorganic properties≦150 and carbon numbers of 19 or more, 150 inorganic Oils with a property ≦200 and a carbon number of 20 or more, 200 inorganic properties ≦250 and an oil with a carbon number of 21 or more, 250 inorganic properties! and contains one or more oils having a carbon number of 22 or more and water, and the content of the oil is 0.005 to 6.
0% by weight, the amount ratio of the hydrophilic ionic surfactant to the total oily component is 1:0.5 to 1:10, and the average particle size is 0.
．． It is a microemulsion characterized by having a diameter of 0.01 to 0.1 μm.

Note that the average particle diameters used here are all measured by dynamic light scattering, and specifically, NIGOM
It was measured using P-270 (manufactured by HIAC/ROYCO).

Hereinafter, the configuration of the present invention will be explained in detail.

As the ionic surfactant used in the present invention, since it is necessary to obtain an oil-in-water microemulsion, H
LB must be hydrophilic, but otherwise ordinary ionic surfactants can be used.

To give a specific example, anionic surfactants include:
For example, fatty acid soaps such as sodium laurate and potassium valmitate, higher alkyl sulfate ester salts such as sodium lauryl sulfate and potassium lauryl sulfate, alkyl ether sulfate ester salts such as polyoxyethylene (hereinafter referred to as POE) and triethanolamine lauryl sulfate. , N-acyl sarcosinates such as sodium lauroyl sarcosinate, higher fatty acid amide sulfonates such as sodium N-myristoyl-N-methyltaurate, phosphate ester salts such as POE sodium oleyl ether phosphate, POE stearyl ether phosphate, etc. Sulfosuccinates such as sodium 2-ethylhexylsulfosuccinate, sodium linear dodecylbenzenesulfonate, triethanolamine linear dodecylbenzenesulfonate,
Alkylbenzenesulfonic acid salts such as linear dodecylbenzenesulfonic acid, monosodium N-lauroylglutamate, disodium N-stearoylglutamate,
Examples include N-acylglutamic acid salts such as monosodium N-myristoyl-L-glutamate.

Examples of the cationic surfactant include alkyltrimethylammonium salts such as stearyltrimethylammonium chloride and lauryltrimethylammonium chloride, dialkyldimethylammonium salts, alkyl quaternary ammonium salts, and alkylamine salts.

As the amphoteric surfactant, for example, 2-undecyl-N
, N, N-(hydroxyethylcarboxymethyl)-2
- imidacillin double-sided surfactant such as imidacillin sodium, 2-cocoyl-2-imitazolinium hydroxide-1-carboxyethyloxy disodium salt, 2
-Betaine surfactants such as heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryl dimethylaminoacetic acid betaine, alkyl betaine, amidobetaine, sulfobetaine, N-lauryl β-alanine, N-stearyl β - Amino acid salts such as alanine and the like can be mentioned.

These ionic surfactants may be used alone or in combination of two or more.

In order to make the oil content of the microemulsion according to the present invention at a ratio of ionic surfactant to oil of 1:2 or more, the structure of the lipophilic group of the ionic surfactant must be Aliphatic hydrocarbons in which the number of carbon atoms in the oil group is 12 or more are preferred. Furthermore, in order to improve the stability at low temperatures, it is preferable that the Kraft point be below room temperature, preferably below 0°C.

The oil used in the present invention is an oil with an inorganicity of 0 on the organic conceptual diagram (Organic Conceptual Diagram, Yoshio Koda, Sankyo Publishing, 1984) and a carbon number of 15 or more; Oil with a carbon number of 16 or more, 20 inorganic ≦50 and a carbon number of 17 or more, 50 inorganic ≦100 and a carbon number of 1
Oil of 8 or more, 100, inorganic ≦150, and carbon number 1
Oil of 9 or more, 150, inorganic ≦200, and carbon number 2
0 or more oil, 200, inorganic ≦250, and carbon number 2
One or more oils, one or more oils that are inorganic and have 22 or more carbon atoms.

It is preferable that these oils are in a liquid state at room temperature, but even if they are solid, there is no problem as long as they are dissolved and become a liquid state when mixed.

As a specific example, oils with an inorganic property of 0 and a carbon number of 15 or more include hydrocarbons such as liquid paraffin, squalane, blistane, paraffin, petrolatum, etc.
Examples of oils that are inorganic≦20 and have a carbon number of 16 or more include hydrocarbons such as squalene, ethers such as dioctyl ether, and oils that are inorganic≦50 and have a carbon number of 1.
Examples of oils with a molecular weight of 7 or higher include diethers such as ethylene glycol dioctyl ether, etc.
Examples of oils having 18 or more carbon atoms include monoesters such as cetyl octoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, myristyl myristate, decyl oleate, and oleyl oleate, isostearyl alcohol, Higher alcohols such as octyldodecanol, etc., 100<inorganic≦
150 and has a carbon number of 19 or more, such as unsaturated higher alcohols such as oleyl alcohol and lanolin alcohol, and examples of oils that are 150, inorganic ≦200 and have a carbon number of 20 or more include high-grade alcohols such as eicosenoic acid. Fatty acids, diesters such as di-2-ethylhexyl sepacate, di-2-ethylhexyl adipate, etc., 200<
Examples of oils that are inorganic≦250 and have a carbon number of 21 or more include chryceryl monoethers such as chrycerol monooleyl ether, acid amides such as lauroyl laurylamine, etc., which are inorganic and have a carbon number of 22 or more. Examples of the above oils include avocado oil, camellia oil, tardle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, basic oil, wheat germ oil, sasanqua oil, castor oil, and linseed oil. Plant and animal oils such as , safflower oil, cottonseed oil, Nino oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, Japanese tung oil, jojoba oil, germ oil, cacao butter, and coconut oil. etc. One or more of these are used.

The stability of a microemulsion tends to improve as the number of carbon atoms is larger and the more nonpolar oil is used. It is better to use

Furthermore, the present inventors discovered that cyclohexane, n-hebutane, isopropyl myristate, and
Even for low molecular weight oils such as dibutyl sepatate, stable microemulsions can surprisingly be obtained by adding the oil according to the limitations of the present invention.

The quantity ratio of such oil and the oil according to the limitations of the present invention is 1:
0. OO1-1: Used at 0.7. Examples of such oils include oils whose inorganicity on the organic conceptual diagram is O and whose carbon number is 5≦carbon number≦14, oil whose inorganicity is 0 and whose carbon number is 5≦carbon≦14, oil whose inorganicity is 0 and whose carbon number is ≦15, Inorganic ≦ 50 and carbon number 7 ≦ carbon number ≦ 16 oil, 50 inorganic ≦ 100 and carbon number 8 ≦ carbon number ≦ 17 oil, 100 inorganic ≦
150 and the number of carbon atoms is 10≦carbon number≦18, 150
Oils that are inorganic≦200 and have a carbon number of 12≦carbons≦19; 200 oils that are inorganic≦250 and have a carbon number of 14≦carbon≦20; One or more types of oil with ≦carbon number≦21, and specific examples include: Inorganicity is O and carbon number is 5≦carbon number≦
Examples of the oil of No. 14 include hydrocarbons such as n-hebutane and n-octane; examples of oils that are inorganic≦20 and have a carbon number of 6≦15 include hydrocarbons such as cyclohexane; Examples of oils that are inorganic ≦50 and have a carbon number of 7≦carbon≦16, such as ethers such as butyl ether, are diethers such as ethylene glycol dibutyl ether, and are inorganic≦100 and have a carbon number of Examples of oils in which carbon number is 8≦17 include monoesters such as isopropyl myristate, ethyl caprate, and ethyl laurate, alcohols such as 2-hebutylnonanol, and oils that are inorganic and have a carbon number of ≦150. Carbon number is 10≦
Examples of oils having carbon number ≦18 include isomyristic acid,
Fatty acids such as isostearic acid and capric acid, dialcohol monoethers such as ethylene glycol monolauryl ether, etc. Oils that are inorganic ≦200 and have a carbon number of 12≦carbon number≦19 include, for example, adipic acid. Diesters such as dibutyl, diisopropyl cepatate, dibutyl cepatate, etc., 200 < inorganic ≦ 250 and the number of carbon atoms is 14 ≦ carbon number ≦ 20, such as acid amides such as butyl laurate, etc. Examples of the inorganic oil having a carbon number of 16≦carbon number≦21 include triglycerides such as tricabroin, and one or more of these may be used.

The microemulsion in the present invention contains 0.1 to 30% of ionic surfactant and 0.005 to 60% of oily component.
%, containing 20 to 99.8% water. In addition, the ratio of nonionic surfactant and oily component is 1:0.5 to 1:1.
0, and the emulsified particle system is 0.01 to 0.1 μm.

Such a microemulsion can be prepared using an emulsifier capable of applying strong shearing force, such as a high-pressure homogenizer or an ultrasonic emulsifier. When using a high-pressure homogenizer, it is preferable to emulsify under a pressure of 400 atm or higher, and more preferably at a temperature of 50° C. or lower and a pressure of 600 atm or higher.

The microemulsion according to the invention does not become cloudy or separate when subjected to any conventional stability tests.

Various other components can be added to the microemulsion of the present invention. Among such components, those listed as water phase components include methyl alcohol,
Ethyl alcohol, propyl alcohol, isopropyl alcohol, ethylene glycol, propylene glycol, 1,3-butylene glycol, glycerin, sorbitol, mannitol, diethylene glycol, dipropylene glycol, polyethylene glycol, sorbitan, sorbitol, maltitol, maltotriose,
There are mannitol, sodium hyaluronate, etc., which are arbitrarily selected and used in actual product systems.

In addition, products to which the microemulsion according to the present invention is applied may contain fragrances, coloring agents, other powders, preservatives, drugs, thickeners, ultraviolet absorbers, chelating agents, other oils, and surfactants, as necessary. , active aids, etc. are added as appropriate.

[Effects of the Invention] As detailed above, the present invention relates to a microemulsion consisting of a hydrophilic ionic surfactant and a specific oil, and is highly practical in terms of safety and functionality. It can be said that there is. In particular, the present invention is useful for liquid cleansers, shampoos, hair tonics, hair lotions, aftershave lotions, body lotions, hair oils, emollient oils, cosmetic lotions, cleansing oils, aerosol products, deodorants, deodorants, etc. It can be used in water-based products such as , pharmaceutical liquids, and bath salts.

[Example] Next, the microemulsion according to the present invention will be described in detail with reference to Examples and Comparative Examples. The present invention is not limited thereby.

[Examples 1 to 13] As an ionic surfactant, potassium dodecyl sulfate 10
Put 20% by weight of the oil shown in the table (see table for inorganicity and carbon number) and water into a beaker, pre-emulsify, emulsify with a high pressure homogenizer (500 atm) at 50°C, and then cool to room temperature. Table 1 shows the evaluation of the condition after 3 months at 5°C, 25°C, and 40°C. For evaluation, those that remain transparent at each temperature even after 3 months and are clearly stable as microemulsions are given a Q, and those that become cloudy and separated immediately or over time are given a ×.

(Hereinafter, blank space) As shown in Table 1, Examples 1 to 13 according to the present invention are as follows:
A good microemulsion was obtained.

(The following is a blank space) [Comparative Examples 1 to 14] The ionic surfactant was 10% by weight of potassium dodecyl sulfate as in Examples 1 to 13, and the oil in Table 2 (see the table for inorganicity and carbon number) 20% by weight and water were used. The preparation method and evaluation method were based on Examples 1 to 13, but the changes over time were immediately after preparation and 1 day later.

(Margin 9 below) As shown in Tables 1 and 3, the excellent effects of the inorganic nature and limited carbon number of the oil according to the present invention have been demonstrated.

[Examples 14 to 27] As an ionic surfactant, potassium dodecyl sulfate 10
% by weight, 0.5% by weight of squalane, 20% by weight of the oil in the table, and 69.5% by weight of water, and after preliminary emulsification, were heated at 50°C using a high-pressure homogenizer (500 atm).
After emulsification at 5°C, 25°C, 4°C,
Table 3 shows the evaluation of the condition after 3 months at 0°C.

The evaluation is based on O, which remains transparent at each temperature even after 3 months and is clearly stable as a microemulsion.
If it becomes cloudy or separates immediately or over time, it is marked as ×.

(The following is a blank space) As shown in Table 3, good microemulsions were obtained in Examples 14 to 27 according to the present invention. This revealed the effect of the combination with low molecular weight oils.

[Example 28] Cleansing jelly (parts by weight) 1) Liquid paraffin 40.02) Fragrance appropriate amount 3) Preservative
Appropriate amount 4) Oleic acid triethanolamine salt 6.0 5) Water 59.06) Propylene glycol 5.01) - Mix 3) and make 7
Heat and dissolve at 0°C.

This is added to a mixture of 4) to 6) heated and dissolved at 70° C. while stirring, and emulsified. 700 yen of this emulsion
The mixture was emulsified using a high-pressure homogenizer at 80° C. under atmospheric pressure to obtain a cleansing jelly with a transparent feel.

The average particle diameter of the oil droplets of the resulting cleansing jelly was measured by dynamic light scattering and was found to be 0.1 μm.

[Example 29] Aqueous translucent topical drug (parts by weight) 1) Indomethacin 1.02) Dibutyl phthalate 8.0 3) Isopropyl myristate 10.04) Squalane 2.05) Potassium isostearate 5.06) Water
74.01) to 4) T-mix and heat to 70°C to dissolve.

This is added to the mixture of 5) and 6) heated and dissolved at 70° C. while stirring, and emulsified. This emulsion was emulsified using a high-pressure homogenizer at 30° C. under a pressure of 700 atm to obtain an aqueous translucent external preparation of indomethacin with a transparent feel.

The average particle diameter of the oil droplets of the obtained aqueous translucent external medicine was measured by dynamic light scattering and was found to be 0.07 μm.

[Example 30 Aqueous translucent topical drug (parts by weight) 1) Clotrimazole 1.02) Dibutyl sepacate 10.0 3) Cetyl isooctanoate 2.54) Squalane 0.55) Myristyltrimethylammonium chloride 5.0 6) Water 81.01) to 4) are mixed and heated to 70°C to dissolve.

This is added to the mixture of 5) and 6) heated and dissolved at 70° C. while stirring, and emulsified. This emulsion was emulsified using a high-pressure homogenizer at 30° C. under a pressure of 700 atm to obtain an aqueous translucent external preparation of clotrimazole with a transparent feel.

The average particle diameter of the oil droplets of the obtained aqueous transparent external medicine was measured by dynamic light scattering and was found to be 0.07 μm.

[Example 31] Hair transparent rinse agent (parts by weight) 1) Liquid paraffin 12.02) Cetyltrimethylammonium bromide 8.03) Water
70.04) Propylene glycol
10.01) f! Heat at near 0°C. This is added to the mixture of 3) to 4) heated and dissolved at 70° C. while stirring, and emulsified. This emulsion was emulsified using a high-pressure homogenizer at 30° C. under a pressure of 700 atm to obtain a transparent rinse agent.

The average particle diameter of the oil droplets of the obtained transparent rinse agent was measured by a dynamic light scattering method and was found to be 0.03 μm.

[Example 32] Hair treatment agent (parts by weight) 1) Isopropyl myristate 29.02) Squalane 5.03) Dicetyldimethylammonium bromide 6.04) Water
50.05) Glycerin
10.01) to 3) 18 Mix by stirring at 0°C.

This is added to the mixture of 4) and 5) dissolved by heating at 70°C, and emulsified. This emulsion was emulsified using a high-pressure homogenizer at 30° C. under a pressure of 700 atm to obtain a transparent and highly viscous hair treatment agent.

The average particle diameter of the oil droplets of the obtained hair treatment agent was measured by a dynamic light scattering method and was found to be 0.1 μm.

Claims (1)

[Claims] A hydrophilic ionic surfactant, an oil whose inorganicity on the organic conceptual diagram is 0 and a carbon number of 15 or more, an oil where 0<inorganicity≦20 and a carbon number of 16 or more, 20<inorganicity≦ 50 and has a carbon number of 17 or more, 50<inorganicity≦100 and a carbon number of 18 or more, 100<inorganicity≦150 and a carbon number of 19 or more, 150<inorganicity≦200 and one or more oils having a carbon number of 20 or more, 200<inorganic≦250 and a carbon number of 21 or more, 250<inorganic and a carbon number of 22 or more, and water. Contains
The content of the oil is 0.005-60% by weight, and the ratio of the hydrophilic ionic surfactant to the total oily component is 1:0.5-60% by weight.
A microemulsion characterized in that the ratio is 1:10 and the average particle diameter is 0.01 to 0.1 μm.