KR102415878B1 - Colesteric liquid crystal-encapsulated complex coacervate particles and cosmetic composition comprising the same - Google Patents

Abstract

The present invention relates to complex coacervate particles encapsulated in cholesteric liquid crystal and a cosmetic composition comprising the same, and more particularly, to a core material, cholesteric liquid crystal, and a coacervate shell surrounding the cholesteric liquid crystal, wherein the coacervate is It relates to a composite coacervate particle (referred to as HA-Crystal) encapsulated in cholesteric liquid crystal, characterized in that it is a composite coacervate formed by electrostatic bonding of a cationic polymer and an anionic polymer, and a cosmetic composition comprising the same.
According to the present invention, conventional cholesterol liquid crystals have a unique sticky and heavy feeling of use and low water solubility, so they cannot be used in skin care formulations. However, in the present invention, cholesterol liquid crystals are encapsulated by encapsulating the The sticky feeling of the steric liquid crystal has been dramatically improved. Therefore, according to the present invention, it is possible to provide a cosmetic composition characterized in that the feeling of use is improved while maintaining the optical properties of the cholesteric liquid crystal.

Description

Cholesteric liquid crystal-encapsulated complex coacervate particles and cosmetic composition comprising the same

The present invention relates to complex coacervate particles encapsulated in cholesteric liquid crystal and a cosmetic composition comprising the same, and more particularly, to a cholesteric liquid crystal as a core material and a coacervate shell surrounding the cholesteric liquid crystal, wherein the coacervate is It relates to a composite coacervate particle encapsulated in cholesteric liquid crystal, characterized in that it is a composite coacervate formed by electrostatic bonding of a cationic polymer and an anionic polymer, and a cosmetic composition comprising the same.

In the cosmetic industry, liquid crystal is used as a material that regulates the delivery system of moisturizing and active substances, and liquid crystal is a material that has both a solid property with a regular molecular arrangement and fluidity like a liquid, and maintains the properties of the intermediate state of the liquid. Lyotropic liquid crystal forms liquid crystal according to concentration, and since it is a phase behavior commonly seen in surfactants, it can be applied to cosmetics as a lamellar liquid crystal, and thermotropic liquid crystal forms liquid crystal by temperature change. A cholesteric liquid crystal composition has unique optical properties and can be used as a cosmetic using these properties. Liquid crystals can be divided into concentration transition liquid crystals and temperature transition liquid crystals according to a phase transition mechanism, which is related to temperature transition, and can form smectic, nematic, and cholesteric liquid crystals according to their arrangement. When the cholesteric liquid crystal is formed, it can be seen with the naked eye by reflecting light in the visible region due to its optical specificity.

Cholesteric liquid crystal displays various colors depending on the wavelength pitch and has a structure similar to skin intercellular lipids, so it has excellent moisturizing power (prior art 1), but due to its lamellar structure, it has poor compatibility with water and has a unique heavy and sticky feeling. . Therefore, the conventional cholesterol liquid crystal has a unique sticky and heavy feeling of use and has a disadvantage that it cannot be used in skin care formulations due to its low water solubility.

Microencapsulation is the process of encapsulating a core material into small droplets during a protective coating. This process is carried out to aid in storage and to handle or control the release of the encapsulated material. Many techniques exist for forming microcapsules. As one technique, complex coacervation is known. Coacervation is the process of separating an aqueous colloid into two liquid phases, one of which is condensed into relatively colloids and the other is diluted into relatively colloids. When only a single type of colloidal material is present, the process is referred to as simple coacervation. However, when a mixture of two (oppositely charged) colloids is present, the process is referred to as complex coacervation. When complex coacervation occurs, the colloid must be ionized or capable of being ionized, and the conditions for coacervation require that the colloid be oppositely charged. Conditions for coacervation can be brought about by the selection of appropriately charged colloids. Alternatively, if an amphoteric colloid (eg protein, eg gelatin) is used, the pH of the colloidal mixture can be adjusted above or below the isoelectric point to impart a suitable charge to the amphiphilic colloid.

Complex coacervate can also be produced by electrostatic bonding of cationic polymer and anionic polymer, and by forming a coacervate shell that adsorbs on the surface of the core material and coats it, it is possible to make composite coacervate particles encapsulating the core material in the coacervate shell. have.

Accordingly, as a result of intensive research efforts to overcome the problems of the prior art, the present inventors confirmed that the sticky feeling of the cholesteric liquid crystal is remarkably improved when the cholesteric liquid crystal is surrounded by a composite coacervate shell to form composite coacervate particles. invention was completed.

KR 10-2014-0147505 A KR 10-2019-0075186 A

Accordingly, a main object of the present invention is to provide complex coacervate particles encapsulated in cholesteric liquid crystal to improve the sticky feeling of use of the cholesteric liquid crystal.

Another method of the present invention is to provide a method for preparing the composite coacervate particles in which the cholesteric liquid crystal is encapsulated.

Another object of the present invention is to provide a cosmetic composition with improved feeling of use including the composite coacervate particles in which the cholesteric liquid crystal is encapsulated.

According to one aspect of the present invention, the present invention consists of a cholesteric liquid crystal as a core material and a coacervate shell surrounding the cholesteric liquid crystal, and the coacervate is a complex coacervate formed by electrostatic bonding of a cationic polymer and an anionic polymer It provides a composite coacervate particle encapsulated in cholesteric liquid crystal, characterized in that.

In the present invention, the cholesteric liquid crystal as the core material means a chiral nematic liquid crystal having a spiral structure in which the director of the nematic liquid crystal is twisted along the spiral axis, and cholesterol, the first discovered liquid crystal, is chiral. Because it was a nematic liquid crystal, it is called a cholesteric liquid crystal. In general, cholesteric liquid crystal is prepared by mixing cholesteryl derivatives, and has excellent visual and aesthetic effects due to its unique optical properties and is widely used as a cosmetic raw material because of its excellent skin moisturizing effect. Cholesterol derivatives that can be used to prepare the cholesteric liquid crystal of the present invention include cholesteryl isostearate, cholesteryl nonanoate, cholesteryl propionate, cholesterol linoleate, cholesteryl oleate, and cholesteryl. From the group consisting of oleyl carbonate, cholesteryl nanonate, cholesteryl chloride, cholesteric oleic carbonate, cholesteric stearate, cholesteryl acetate, cholesteryl benzoate and cholesteryl caprylate, etc. It may be one or more selected.

In the present invention, electrostatic bonding refers to all interactions including ionic bonding between a cationically charged material and an anionically charged material by electrostatic attraction.

In the present invention, the cationic polymer may be any cationic polymer capable of being cationically charged and capable of electrostatically bonding with an anionic polymer to form a complex coacervate, but preferably, the cationic polymer is agar, Cholesteric, characterized in that at least one selected from the group consisting of xanthan, gelatin, tylcellulose, polyacrylate, carboxyvinyl polymer, polyamide, polyvinyl alcohol, polyvinylpyrrolidone, albumin, chitosan, or polylysine Provided is a composite coacervate particle in which a liquid crystal is encapsulated.

In the present invention, the cationic polymer may be any cationic polymer capable of being cationically charged and capable of electrostatically bonding with an anionic polymer to form a complex coacervate, but preferably, the cationic polymer is agar, Cholesteric, characterized in that at least one selected from the group consisting of xanthan, gelatin, tylcellulose, polyacrylate, carboxyvinyl polymer, polyamide, polyvinyl alcohol, polyvinylpyrrolidone, albumin, chitosan, or polylysine Provided is a composite coacervate particle in which a liquid crystal is encapsulated.

In the present invention, the anionic polymer may be any anionic polymer capable of being anionically charged to form a complex coacervate by electrostatically bonding with the cationic polymer, but preferably, gum arabic, carboxymethyl cellulose , gelatin, gellan, carboxyvinyl polymer, low methoxyl pectin, xanthan gum, sodium carboxymethyl guar gum, sodium hyaluronate, alginate, dextran sulfate, alginic acid, or carrageenan, characterized in that at least one selected from the group consisting of Provided is a composite coacervate particle encapsulated in a steric liquid crystal.

In the present invention, the composite coacervate provides composite coacervate particles encapsulated in cholesteric liquid crystal, characterized in that it further comprises a crosslinking agent or a stabilizer for curing or stabilizing the composite coacervate. The crosslinking agent or stabilizer stabilizes the coacervate or increases its strength through crosslinking or matrix formation.

In the present invention, preferably, the crosslinking agent or stabilizer is glutaraldehyde, formaldehyde, methacrylic anhydride (MAA), transglutaminase, tannic acid, EDC (1-ethyl-3-(3) -dimethylami-nopropyyl) carbodiimid), hyaluronic acid, silica, and provides a composite coacervate particle encapsulated in cholesteric liquid crystal, characterized in that at least one selected from a block copolymer.

In the present invention, preferably, the crosslinking agent or stabilizer includes hyaluronic acid, silica and a block copolymer, and more preferably, the hyaluronic acid may be a mixture of high molecular weight hyaluronic acid and low molecular weight hyaluronic acid, and block air The copolymer may be a PEG-PCL copolymer or a PS-PCL copolymer having both hydrophilic/lipophilic groups.

In the present invention, when hyaluronic acid, silica, and a block copolymer are included as a crosslinking agent or stabilizer, the silica or block copolymer is arranged like a linker between the coacervate shell and the core material as the primary stabilizer. And, it provides a composite coacervate particle encapsulated in cholesteric liquid crystal, characterized in that hyaluronic acid is oriented outside the coacervation shell as a secondary stabilizer to form a matrix shell.

According to another aspect of the present invention, there is provided a method for preparing complex coacervate particles in which cholesteric liquid crystal is encapsulated, comprising the following steps:

(a) preparing a cholesteric liquid crystal to be encapsulated in the coacervate particles;

(b) homogenizing the cationic polymer and the anionic polymer in an aqueous phase to prepare a coacervate emulsion;

(c) adding the cholesteric liquid crystal of step (a) to the coacervate emulsion of step (b);

(d) adding an acidic or basic substance to adjust the pH; and

(e) adding a crosslinking agent or stabilizer to cure or stabilize the coacervate particles; and

(f) recovering the coacervate particles after washing the precipitate separated from the result of step (e).

In the present invention, the acidic or basic material in step (d) may be any chemical or natural material capable of adjusting the pH by being acidic or basic. As a chemical substance, the acidic substance may be at least one selected from the group consisting of citric acid, acetic acid, aqueous ammonia, hydrochloric acid, sulfuric acid, etc., and the basic substance is sodium citrate, calcium hydroxide, sodium hydroxide, tromethamine, triethanolamine, etc. One or more may be selected from the group consisting of. Preferably, the acidic substance is an acidic natural product selected from amino acid complex, lemon extract, lemon fermented vinegar, aloe vera extract, AHA/BHA complex, or vitamin extract, and the basic substance is avocado extract, celery extract, broccoli extract, yellow lotus extract, It provides a method for producing a complex coacervate particle encapsulated in cholesteric liquid crystal, characterized in that it is a basic natural product selected from Hwangbaek extract, Rehabilitation plant water, snail mucus extract, black pearl extract, or menthol extract.

According to another aspect of the present invention, there is provided a cosmetic composition comprising the complex coacervate particles encapsulated in the cholesteric liquid crystal according to the present invention.

In the present invention, preferably, the optical properties of the cholesteric liquid crystal are maintained while providing a cosmetic composition characterized in that the feeling of use is improved. In the experimental example of the present invention, it was confirmed that the composite coacervate particles encapsulated in the cholesteric liquid crystal according to the present invention exhibited a visual aesthetic effect by maintaining optical properties, and the feeling of use was improved compared to the cholesteric liquid crystal not encapsulated in the complex coacervate. confirmed to be.

Components included in the cosmetic composition of the present invention include components commonly used in cosmetic compositions in addition to the complex coacervate particles encapsulated in cholesteric liquid crystal as an active ingredient, for example, solvents, stabilizers, solubilizers, emulsifiers, vitamins, pigments and conventional adjuvants such as perfumes, and carriers.

The cosmetic composition of the present invention may be prepared in any formulation conventionally prepared in the art, but preferably, a lotion, a nutritional lotion, a nutritional cream, a massage cream, a nutritional essence, a pack, a makeup base, a foundation, and a body oil. It is characterized in that it is prepared in a formulation selected from the group consisting of , hair oil, shampoo, and rinse. Regardless of the formulation example of the cosmetic composition, as long as the cholesteric liquid crystal of the present invention contains the encapsulated complex coacervate particles, the visual aesthetic effect may be maintained and the feeling of use of the cosmetic composition may be improved.

According to the present invention, conventional cholesterol liquid crystals have a unique sticky and heavy feeling of use and low water solubility, so they cannot be used in skin care formulations. However, in the present invention, cholesterol liquid crystals are encapsulated by encapsulating the The sticky feeling of steric liquid crystal was remarkably improved, and the sticky and heavy feeling of cholesteric liquid crystal was improved to make it fresh and moist, giving the skin a moisturizing feeling. Therefore, according to the present invention, it is possible to provide a cosmetic composition characterized in that the feeling of use is improved while maintaining the optical properties of the cholesteric liquid crystal.

1 is a schematic diagram of a complex coacervate particle structure in which a cholesteric liquid crystal is encapsulated.
2 is a graph comparing the feeling of use between a conventional cholesteric liquid crystal (CLC) and a composite coacervate particle (HA-Crystal) encapsulated in a cholesteric liquid crystal of the present invention.
3 is a photograph taken before and after HA-Crystal properties and rolling properties to test the optical properties of the composite coacervate particles encapsulated in cholesteric liquid crystal of the present invention. Figure 3a is a HA-Crystal in essence / HA-Crystal polarized image, Figure 3b is an image before / after HA-Crystal Rolling.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and therefore, the scope of the present invention is not to be construed as being limited by these examples.

Example: Preparation of composite coacervate particles encapsulated in cholesteric liquid crystal

(a) preparing the cholesteric liquid crystal to be encapsulated in the coacervate particles

Cholesteryl chloride (CC), cholesteryl stearate (CS), and cholesteryl benzoate (CB) in the ratios shown in Table 1 below were homogeneously mixed at high temperature (70-80 degrees) using AZI MIXER. A cholesteric liquid crystal composition exhibiting various colors was prepared by mixing.

Content (g)
Raw material name liquid crystal 1 liquid crystal 2 liquid crystal 3 liquid crystal 4 Cholesteryl Chloride (CC) 3.0 2.5 2.0 3.5 Cholesteryl Stearate (CS) 6.0 4.0 3.0 5.0 Cholesteryl Benzoate (CB) 1.5 4.0 5.0 2.0 colour RED GREEN BLUE VIOLET

(b) homogenizing the cationic polymer and the anionic polymer in an aqueous phase to prepare a coacervate emulsion;

Agar as a cationic polymer was put into purified water to make a 5% solution, and carrageenan as an anionic polymer was added to purified water to make a 5% solution, and then the two solutions were homogenized with AZI MIXER at 500 rpm for 30 minutes to prepare a coacervate emulsion.

(c) adding the cholesteric liquid crystal raw material of step (a) to the coacervate emulsion of step (b);

Of the cholesterol liquid crystal composition prepared in (a) above, a cholesteryl liquid crystal (CLC) made of liquid crystal 1 was placed in the aqueous emulsion of step (b) and encapsulated in coacervate particles using AZI MIXER.

(d) adding an acidic or basic substance to adjust the pH; and

Coacervation is performed by adjusting the pH to 7 to 9 using citric acid (chemical) or lemon extract (natural) as an acidic material, and sodium citrate (chemical) or reincarnation (natural) as a basic material. can induce

(e) adding a crosslinking agent or stabilizer to cure the coacervate particles;

In the present invention, glutaraldehyde (GA), hyaluronic acid (HA, 1.8~0.6Mda polymer + 0.5~10.1Kda low molecular weight), silica, and PEG-PCL block copolymer were used as crosslinking agents or stabilizers. The names and contents of raw materials used in Examples and Comparative Examples are shown in Table 2 below.

Content (g) Raw material name Example 1 Example 2 Example 3 Comparative Example 1 cholesteric liquid crystal 1.0 1.0 1.0 10.0 baby 0.5 0.5 0.5 - carrageenan 0.7 0.7 0.7 - lemon extract 3.0 3.0 - - Resurrection Seconds 5.0 5.0 - - citric acid - - 0.2 - sodium citrate - - 0.3 - HA 3.0 3.0 - - PEG-PCL block copolymer - 0.5 - - Silica - 0.3 - - GA - - 3.0 -

(f) recovering the coacervate particles after washing the precipitate separated from the emulsion;

It is washed with purified water to remove unreacted substances in coacervation and to obtain coacervate particles (HA-Crystal) (repeat 3 times)

Experimental Example 1: Test for improving feeling of use of composite coacervate particles encapsulated in cholesteric liquid crystal

In order to compare the feeling of use of the composite coacervate particles in which the cholesteric liquid crystal prepared according to Examples 1 to 3 are encapsulated and the cholesteric liquid crystal prepared according to Comparative Example 1 above, these were dissolved in purified water and then 10 panelists were targeted. After applying the same amount to the back of the hand, each item of spreadability, ease of use, stickiness, absorption, and residual feeling was scored out of 5 points and averaged. The higher the score for spreadability, ease of use, and absorption, the better the feeling of use, and the lower the score for stickiness and residual feeling. The results are shown in Table 3 below.

spreadability Ease of use stickiness absorptivity residual feeling Example 1 4.0 4.0 2.5 4.0 4.0 Example 2 4.0 4.0 2.0 4.0 4.0 Example 3 3.0 4.0 2.0 4.0 4.0 Comparative Example 1 3.0 2.0 4.0 2.0 5.0

As shown in the table above, the composite coacervate particles (Examples 1 to 3) according to the present invention have superior usability compared to the cholesteric liquid crystal (Comparative Example 1) in all aspects of spreadability, ease of use, stickiness, absorption, and residual feeling. was shown. In the case of only hyaluronic acid without block copolymer and silica (Example 1), a little stickiness characteristic of natural polymer was observed, but it showed much lower stickiness than that of cholesteric liquid crystal (Comparative Example 1). When hyaluronic acid, block copolymer, and silica were all used (Example 2), it was the best in all aspects of spreadability, ease of use, stickiness, absorption, and residual feeling.

2 is a graph comparing the feeling of use of the cholesteric liquid crystal (CLC) according to Comparative Example 1 and the composite coacervate particles (HA-Crystal) in which the cholesteric liquid crystal is encapsulated according to Example 2.

Experimental Example 2: Optical properties maintenance test of composite coacervate particles encapsulated in cholesteric liquid crystal

Figure 2a is a photograph of the properties of the prepared HA-Crystal dispersed in the essence and particles taken with a polarizing microscope. Figure 2b is a photograph before and after rolling HA-Crystal on the back of the hand (upper) and the desk (lower). From the result of Figure 2, it can be seen that the composite coacervate particles encapsulated in the cholesteric liquid crystal according to the present invention are not disturbed by the coacervate shell and maintain the optical properties of the cholesteric liquid crystal.

Cosmetics of various formulation examples were prepared using the composite coacervate particles ( HA-Crystal ) encapsulated in the cholesteric liquid crystal of the above Examples.

Formulation Example 1: Preparation of lotion containing HA-Crystal composition

A lotion was prepared in a conventional manner with the composition described in the table below.

ingredient content(%) HA-Crystal 0.5 Carbomer 0.05 tromethamine q.s Glycerin 3 BG 4 PEG-60 Hydrogenated Castor Oil 0.3 EDTA 0.02 preservatives, fragrances q.s Purified water To 100

Formulation Example 2: Preparation of Essence Containing HA-Crystal Composition

Essence was prepared in a conventional manner with the composition described in the table below.

ingredient content(%) HA-Crystal One Hydroxyethyl acrylate/sodium acryloyl dimethyl taurate copolymer 0.2 Glycerin 7 BG 5 allantoin 0.1 betaine 0.2 Polyglyceryl-10 Stearate 0.1 EDTA 0.02 preservatives, fragrances q.s Purified water To 100

Formulation Example 3: Preparation of nutritional cream containing HA-Crystal composition

Nutrient cream was prepared in a conventional manner with the composition described in the table below.

ingredient content(%) HA-Crystal 0.5 Ammonium Acryloyl Dimethyl Taurate/Vpicopolymer 0.3 Glycerin 5 BG 7 squalane 2 Caprylic/Capric Triglycerides 3 Sorbitan Stearate One cetearyl alcohol One Polysorbate 60 0.5 EDTA 0.02 preservatives, fragrances q.s Purified water To 100

Although the present invention has been described with reference to the above embodiment, it will be understood that this is only exemplary, and that various modifications and equivalent other embodiments are possible therefrom by those skilled in the art to which the present invention pertains. . Therefore, the true technical protection scope of the present invention will have to be determined by the technical matters of the appended claims.

Claims (7)

It consists of a core material cholesteric liquid crystal and a coacervate shell surrounding the cholesteric liquid crystal, wherein the coacervate is a complex coacervate formed by electrostatic bonding of a cationic polymer and an anionic polymer, does not contain a fat-soluble polymer, and does not contain a crosslinking agent or It further contains hyaluronic acid (HA) as a stabilizer, and the hyaluronic acid forms a matrix shell on the outside of the coacervate shell to have a double-shell structure as a whole. Coacervate particles. According to claim 1, wherein the cationic polymer is agar, xanthan, gelatin, tylcellulose, polyacrylate, carboxyvinyl polymer, polyamide, polyvinyl alcohol, polyvinylpyrrolidone, albumin, chitosan, or polylysine consisting of at least one selected from the group, and the anionic polymer is gum arabic, carboxymethyl cellulose, gelatin, gellan, carboxyvinyl polymer, low methoxyl pectin, xanthan gum, sodium carboxymethyl guar gum, sodium hyaluronate, alginate, dextran Composite coacervate particles encapsulated in cholesteric liquid crystal, characterized in that at least one selected from the group consisting of sulfate, alginic acid, and carrageenan. delete delete A method for preparing complex coacervate particles in which cholesteric liquid crystals are encapsulated, comprising the following steps:
(a) preparing a cholesteric liquid crystal to be encapsulated in the coacervate particles;
(b) homogenizing the cationic polymer and the anionic polymer in an aqueous phase to prepare a coacervate emulsion;
(c) adding the cholesteric liquid crystal of step (a) to the coacervate emulsion of step (b);
(d) adding an acidic or basic substance to adjust the pH; and
(e) adding hyaluronic acid (HA) as a crosslinking agent or stabilizer for curing or stabilizing the coacervate particles; and
(f) recovering the coacervate particles after washing the precipitate separated from the resultant of step (e). A cosmetic composition comprising the complex coacervate particles encapsulated in the cholesteric liquid crystal according to claim 1 or 2. The cosmetic composition according to claim 6, wherein the feeling of use is improved while maintaining the optical properties of the cholesteric liquid crystal.

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