JPS63126544A - Microemulsion - Google Patents

Abstract

PURPOSE:To enhance the temp. stability of the title microemulsion by mixing specified amts. of a hydrophilic nonionic 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 surfactant, one or >=2 kinds among the >=15C oil at 0 inorg. property on the org. conceptual chart, the >=16C oil at 0<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. The microemulsion, wherein the ratio of the hydrophilic nonionic surfactant to the oil is controlled to 1/0.5-1/7 and the particle diameter is adjusted to 0.01-0.1mum, is thus obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a microemulsion that uses a nonionic surfactant and is capable of stably blending a large amount of oil over a wide temperature range, and is suitable for use in, for example, pharmaceuticals, Used in fields such as cosmetics.

[Prior Art] Conventionally known microemulsions using nonionic surfactants are as follows.

That is, when a hydrocarbon such as cyclohexane or n-heptane is added to an aqueous solution of a nonionic surfactant such as 1so-RCHO(CH2CH2O) 9H and the temperature is increased by 1'J, the amount of the nonionic surfactant increases. A region appears where the amount of solubilized hydrocarbon M (oil) increases rapidly in front of the water (
Kozo Shinoda, 209-225, solutions and solubility, round neck). It is known that the solubility of oil in the aqueous phase increases dramatically in the 1W range from the solubilization limit temperature to Kiyoshi shown in the phase diagram, forming a so-called microemulsion.

However, microemulsions (1w region) with increased oil solubilization obtained using nonionic surfactant-hydrocarbon systems, which have been studied in the past, are extremely difficult to achieve because the hydrophilic-lipophilic balance of the system is maintained. It exists only in a narrow temperature range (approximately 1°C to 10°C); outside this range, the system becomes cloudy immediately or over time, and eventually separates into water and oil.

[Problems to be Solved by the Invention] For this reason, it has been considered difficult to use microemulsions in products intended for use at normal temperatures from the viewpoint of stability.

However, the ability of microemulsions to uniformly dissolve a large amount of oil with a small amount of nonionic surfactant is extremely useful, and creating microemulsions with high temperature stability has been a challenge for researchers.

In view of this current situation, the present researchers conducted intensive research to obtain microemulsions with excellent temperature stability, and as a result, they found that nonionic surfactants, carbon numbers, and inorganic properties in the organic concept diagram were limited. Surprisingly, by using oil, the temperature at which the hydrophilic-lipophilic balance of the system is apparently not maintained, i.e., several tens of times lower than the temperature of the system,
They discovered that microemulsions exist stably even at low temperatures, and that stable microemulsions can be obtained over a very wide temperature range, leading to the completion of the desired invention.

[Means for Solving the Problems] That is, the present invention uses a hydrophilic nonionic surfactant, an oil having 0 inorganic properties on the organic conceptual diagram and 15 or more carbon atoms, and 0 inorganic surfactants. ≦20 and an oil with a carbon number of 16 or more, 2
0 inorganic ≦50 and carbon number 17 or more, 50 inorganic ≦100 and carbon number 18 or more, 100 inorganic ≦150 and carbon number 19 or more, 150 One or more of the following: oils that are inorganic≦200 and have a carbon number of 20 or more; and water, the ratio of hydrophilic nonionic surfactant to oil is 1:0.5 to 1:7, and the particle size is 0.
The present invention relates to a microemulsion characterized in that the microemulsion has a particle diameter of 01 to 0.1 μm.

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

The nonionic surfactants used in this study were:
It must be hydrophilic, but otherwise ordinary nonionic surfactants can be used. Specifically, polyoxyethylene (hereinafter referred to as POE) sorbitan monooleate, POE sorbitan monostearate, POE
POE sorbitan fatty acid esters such as OE sorbitan trioleate, POE sorbitan monooleate, P
O
POE monooleate, POE distearate, POE
POE fatty acid esters such as Geotz, :C-to, Po
E oleyl ether, POE stearyl ether, PO
E-behenyl ether, POE2-octyldodecyl ether, POE2-hexyldecyl ether, POE2-
POE alkyl ethers such as hebutyl undecyl ether, POE 2-decyl tetradecyl ether, POE 2-decyl pentadecyl ether, POE cholestanol ether, POE such as POE nonylphenyl ether, etc.
Alkylphenyl ethers, POE-POP block copolymers, POE-POP cetyl ether, POE
-POE2-decyltetradecyl ether, POE-P
POE-POP alkyl ethers such as OP hydrogenated lanolin, POE castor oil or hydrogenated castor oil derivatives such as POE castor oil, POE beeswax lanolin derivatives such as POE sorbit beeswax, sugar esters such as sucrose oleate monoester, Examples include polyglycerin monoalkyl esters and monoalkyl ethers.

These hydrophilic nonionic surfactants may be used alone or in combination of two or more. Preferably, the HLB is 10 to 20.

Note that in order to make the oil content of the microemulsion according to the present invention at a ratio of hydrophilic nonionic surfactant to oil of 1:2 or more, the hydrophilic nonionic surfactant must be The structure of the lipophilic group is preferably an aliphatic hydrocarbon having 16 or more carbon atoms. Furthermore, the oil content of the microemulsion, hydrophilic nonionic surfactant:
In order to achieve an oil ratio of 1:2.5 or more, the number of carbon atoms in the lipophilic group is preferably 20 or more, and the aliphatic hydrocarbon preferably contains a branch or a double bond.

The oil used in the present invention is an oil whose inorganicity on the organic conceptual diagram (Organic Conceptual Diagram, written by Yoshio Koda, Sandai Publishing, 1984) is O and whose carbon number is 15 or more, and an oil with a carbon number of 16 or more, 20 inorganic ≦50 and an oil with a carbon number of 17 or more, 50, inorganic ≦100, and a carbon number 1
Oil of 8 or more, 100 inorganic ≦159 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, 250<one or more oils that are inorganic and have 22 or more carbon atoms.

It is preferable that these be in a liquid state at room temperature, but there is no problem even if they are solid as long as they are dissolved and become a liquid state when mixed. As specific examples, examples of oils with an inorganic property of 0 and a carbon number of 15 or more include hydrocarbons such as liquid paraffin, squalene, blistane, paraffin, and petrolatum; Examples of oils with a carbon number of 16 or more include ethers such as hydrocarbon dioctyl ether such as squalene; examples of oils that are inorganic ≦50 and have a carbon number of 17 or more include diethers such as ethylene glycol dioctyl ether; Examples of oils that are inorganic≦100 and have a carbon number of 18 or more include cetyl octoate, octyldodecyl myristate,
Monoesters such as isopropyl palmitate, butyl stearate, myristyl myristate, decyl oleate, oleyl oleate, higher alcohols such as isostearyl alcohol and octyldodecanol, 100
Examples of oils that are inorganic ≦150 and have a carbon number of 19 or more include higher alcohols such as oleyl alcohol and lanolin alcohol; examples of oils that are inorganic ≦200 and have a carbon number of 20 or more include eicosenoic acid. Higher fatty acids such as di-2-ethylhexyl sebacate, di-2-ethylhexyl adipate, etc., diesters such as di-2-ethylhexyl adipate, 20
Examples of oils that are inorganic and have a carbon number of 21 or more include chryceryl monoethers such as chrycerol monooleyl ether, acid amides such as lauroyl laurylamine, and oils that are inorganic and have a carbon number of 250 or more. Examples of oils having 22 or more include avocado oil, camellia oil, tardle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, buma oil, persic oil,
Wheat germ oil, sasanquat oil, castor oil, linseed oil, safflower oil, cottonseed oil, eno oil, soybean oil, peanut oil, tea seed oil,
Plant and animal fats and oils such as kaya oil, rice bran oil, linden oil, Japanese tung oil, jojoba oil, germ oil, cacao butter, coconut oil, lanolin, acetic acid lanolin, and liquid lanolin are exemplified. One or more types 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

In the present invention, surfactants and oils other than those mentioned above may also be blended within a range that does not impair the objectives and effects of the present invention. In that case, it is desirable that the HLB of the mixed surfactant and the inorganicity of the mixed oil remain within the above ranges.

The microemulsion in the present invention contains 0.1 to 30% of a hydrophilic nonionic surfactant and 0.1 to 60% of an oil.
%, containing 20 to 99.8% water. The ratio of hydrophilic nonionic surfactant to oil is 1:0.5 to 1:
7, preferably 1:1 to 1:5.

The emulsified particle size is 0.01 to 0.1 μm.

The microemulsion according to the present invention is characterized by its stability over time over a wide temperature range, and as long as it is used at a lower temperature than normal, no clouding or separation will occur in any conventional stability test. In addition, since a large amount of oil can be stably blended with a much smaller amount of nonionic surfactant than conventional solubilization systems, it can be said to be extremely safe.

Such microemulsions can also be prepared using emulsifiers that can apply strong shear forces, such as high-pressure homogenizers (particularly under high pressure), but these methods generally reduce the amount of nonionic surfactant relative to the oil. It is not possible to obtain a good microemulsion unless the amount is increased. Moreover, it is not easy to obtain a microemulsion with a particle size of 0.05 μm or less using such a method.

On the other hand, in producing this microemulsion, the temperature of the system is once raised above the solubilization limit temperature of the system,
If you use the method of cooling after that, there is no need to use a special emulsifier, and you can not only easily prepare a microemulsion with a simple stirrer and a temperature-controlled tank, but also adjust the ratio of emulsifier to oil. By changing the particle size of the microemulsion, it is possible to control the particle size of the microemulsion with high precision (see Examples), and a microemulsion having a particle size of 0.05 μm or less can be easily prepared, and a more stable system can be obtained. At the same time, it is also possible to save labor in the manufacturing process.

In addition to the hydrophilic nonionic surfactant, oil, and water, various other components can be added to the microemulsion of the present invention. Among such components, those listed as aqueous phase components include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, ethylene glycol, propylene glycol,
, 3-butylene glycol, glycerin, sorbitol, mannitol, diethylene glycol, dipropylene glycol, polyethylene glycol, sorbitan, sorbitol, maltitol, maltotriose, mannitol, sodium hyaluronate, etc., and can be selected arbitrarily depending on the actual product system. It is used in

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 nonionic surfactant and a limited amount of oil, and a method for producing the same, which is difficult to achieve with conventional microemulsions. In addition to significantly improving temperature stability, compared to conventional solubilization systems, it is possible to stably blend a large amount of oil with a much smaller amount of nonionic surfactant, which improves safety and functionality. It can be said that it is highly practical. Furthermore, in the industrial field, it has high utility value due to its efficiency. In particular, because of the advantages it has, the present invention provides liquid cleansers, hair tonics, hair lotions, aftershave lotions, body lotions, hair oils, emollient oils, cosmetic lotions, cleansing oils, aerosol products,
It can be used in water-based products such as deodorizers, deodorants, pharmaceutical liquids, and bath salts.

[Example] Next, the microemulsion related to the present product will be explained in detail using Examples and Comparative Examples. The present invention is not limited thereby.

[Examples 1 to 13] As a nonionic surfactant, 10% by weight of POE (20) 2-decyltetradecyl ether, 10% by weight of the oil in the table (for inorganicity and carbon number, see m in the table), and water. was placed in a beaker, heated to 95°C, stirred, and then returned to room temperature. The condition after 3 months was evaluated, and the results are shown in Table 1. The evaluation is rated O if it remains transparent even after 3 months and is clearly stable as a microemulsion, and rated × if it becomes cloudy and separates immediately or over time.

As shown in Table 1, good microemulsions were obtained in Examples 1 to 13 according to the present invention.

(Left below) [Comparative Examples 1 to 8] A nonionic surfactant was added to PO in the same manner as Examples 1 to 13.
E (20) 2-decyltetradecyl ether 10% by weight, oil in Table 2 (see table for inorganicity and carbon number) 10
% by weight and water were used. The preparation method and evaluation method are based on Examples 1 to 13.

As shown in Table 1 and Table 3, the excellent effects of the inorganic nature and limited carbon number of the oil according to the present invention were demonstrated.

[Examples 14 to 17] POE (14) 2-octadodecyl ether (A) 10
Add light liquid paraffin (B) and purified water in the amounts shown in Table 3 based on the weight%, and maintain the temperature above the solubilization limit temperature (95°C).
After raising the temperature to , the mixture was cooled to room temperature while stirring to obtain a microemulsion. As shown in Table 3, the particle size of the microemulsion increased as the amount of oil relative to the amount of surfactant increased. Since there is regularity in the ratio, a microemulsion with any particle size can be easily prepared by changing the ratio of surfactant to oil.

Table 3 (% in the figure is % by weight) [Example 18 (parts by weight) 1) Squalane 8.02) Olive oil 2.03) Vitamin E acetate 0.1 4) Flavoring 0.15) Preservative Appropriate amount 6 )poEI-
(20) 2-decyltetradecyl ether
5.07) Water 74°,
88) Glycerin 10.01) ~6
) and heated to 80℃, add 30 parts of 7) to 80
℃ and add to 1) to 6). Thereafter, the mixture was cooled to room temperature while stirring, and the remainder of 7) and 8) were mixed to obtain a translucent serum.

The average particle diameter of the oil droplets of the obtained beauty serum was measured by dynamic light scattering and was found to be 0.05 μm. When the stability of this product over time was investigated, there was no change in appearance for more than 6 months under any conditions of 40°C, 25°C, and 0°C, and the particle size also hardly changed.

[Example 19 (parts by weight) 1) l! ! Quality liquid paraffin 45.02)
POE (14) 2-octyl dodecyl ether 9.03) Fragrance
Appropriate amount 4) Preservatives
Appropriate amount 5) Water 41
．． 06) Propylene glycol 5.01)
-5) are mixed and heated to 85°C, cooled while stirring, and when the temperature reaches 70°C, 6) is added.

Further, the mixture was cooled to room temperature while stirring, and a translucent jelly-like cleansing jelly was obtained.

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.

This cleansing jelly had a high cleaning effect, could be easily washed off with water, and had a good feeling of use.

[Example 20] (Parts by weight) 1) Dexamethacin acetate 0.0252) Tricabroin 6.9753) POE (
14) 2-Octyldodecyl ether 5.04) Water
83.05) Glycerin
5.01) to 5) were mixed and heated to 75°C,
The mixture was cooled to room temperature with stirring to obtain a transparent aqueous external preparation of dexamethacin acetate, which is a poorly water-soluble drug.

The average particle diameter of the oil droplets of the obtained external preparation was measured by dynamic light scattering and was found to be 0.03 μm.

[Example 21 (parts by weight) 1) Clotrimazole 1.02) 2-
Cetyl ethylhexanoate 20.03) POE
(20') Oleyl ether 7.04) Water
62.05) Propylene glycol
5.01) to 3) are mixed and dissolved by heating at 75°C.

Add this to the mixed solution of 4) and 5) while stirring and emulsify. 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 0.08 μm.

Patent applicant: Shiseido Co., Ltd. Procedural amendment (voluntary) January δ, 1985 1, Indication of the case 1988 Patent Application No. 274531 2, Name of the invention Microemulsion 3, Person making the amendment Relationship with the case Contents of amendments to column 5 of “Claims” and “Detailed Description of 1 Invention” of the patent applicant's specification (1) The scope of claims will be amended as shown in the attached sheet.

(2) The text 3 rows 1 from the bottom of page 4 of the specification should be amended to read ``inorganic and''.

(3) "Regarding" in the 3rd line of page 5 of the specification, and in the 1st line of the same specification, the particle diameters used here are all average particle diameters measured by dynamic light scattering, and the specific N I
COMP-270 (manufactured by HI AC/rtOYcO)
It was measured by (4) Page 8 of the specification, line 2 101 Inorganic dekatsu.''
I will correct it.

(5) In the specification, page 11, line 1, "1 Milk 7 particle diameter" should be corrected to "oil droplet particle diameter."

(6) On page 13, line 11 of the specification, the statement ``Regarding an emulsion and its manufacturing method'' has been amended to read ``Regarding an emulsion.''

(7) Item 81 of page 21 of the specification: ``Obtained aqueous transparent topical drug'' should be corrected to ``Obtained aqueous translucent topical drug.''

Above (Attachment) 2. Claims A hydrophilic nonionic surfactant, an oil with an inorganicity of 0 on the organic conceptual diagram and a carbon number of 15 or more, 0 and inorganicity≦20
and an oil with a carbon number of 16 or more, 20, inorganic ≦50 and a carbon number of 17 or more, 50, an inorganic ≦100 and a carbon number of 18 or more, 100, an inorganic ≦150, and an oil that has a carbon number of 18 or more. Oil with carbon number 19 or more, 150 inorganic ≦200 and carbon number 20 or more, 200 inorganic ≦250 and carbon number 21 or more, 250 inorganic and carbon number 22 Consisting of one or more of the above oils and water,
The ratio of hydrophilic nonionic surfactant to oil is 1:0゜5
A microemulsion characterized in that the ratio is 1:7 and the particle size is 0.01 to 0.1 μm.

Claims (1)

[Claims] A hydrophilic nonionic surfactant, an oil with an inorganicity of 0 on the organic conceptual diagram and a carbon number of 15 or more, 0<inorganicity≦20
and has a carbon number of 16 or more, 20<inorganicity≦50 and a carbon number of 17 or more, 50<inorganicity≦100 and a carbon number of 18 or more, 100<inorganicity≦150, and Oil with a carbon number of 19 or more, 150<inorganic≦200 and 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 It consists of one or more of the above oils and water, and the ratio of the hydrophilic nonionic surfactant to the oil is 1:0.
A microemulsion characterized by having a ratio of 5 to 1:7 and a particle size of 0.01 to 0.1 μm.