KR20070042298A - Cationic polymer nanocapsules for the stabilization of active ingredients and the process for preparing the same, and the cosmetic composition containing the nanocapsules - Google Patents

Abstract

The present invention relates to a water-dispersible cationic polymer nanocapsules stabilized with an oil-soluble active substance, a method for preparing the same, and a cosmetic composition containing the water-dispersible cationic polymer nanocapsules. More specifically, the water dispersible cationic polymer nanocapsules of the present invention comprises the steps of: (1) polymerizing a hydrophobic polymer having a cationic functional group capable of adsorbing an active material; And (2) dissolving the hydrophobic polymer and oil-soluble active ingredient in step (1) in an organic solvent and then mixing the water phase and the organic phase while stirring to prepare an emulsion, and evaporating the organic phase to collect the oil-soluble active ingredient present in the water phase. Preparing a nanocapsule, wherein the cationic polymer nanocapsules prepared by the above steps are prepared in the cationic group in which the oil-soluble active substance is present in the polymer particles. It is adsorbed, and it shows an excellent stabilization effect with a double stabilization system that blocks the active material from external stimulation by the cation group and the polymer wall inside the particle.

Water dispersion * Nanocapsule * Active substance * Cationic * Moiety

Description

Cationic polymer nanocapsules for the stabilization of active ingredients and the process for preparing the same, and the cosmetic composition containing the nanocapsules

1 is a transmission electron microscope photograph of a cationic polymer nanocapsule (Example 1) containing a retinol prepared in the present invention.

The present invention relates to a water-dispersible cationic polymer nanocapsules stabilized with an oil-soluble active substance, a method for preparing the same, and a cosmetic composition containing the water-dispersible cationic polymer nanocapsules.

 It is widely used in cosmetics due to its excellent effect of improving skin wrinkles and strengthening moisturizing power, but stabilizing useful active substances that have a problem of discoloration, discoloration and lower potency due to contact with external stimuli such as air or moisture. Research is actively underway. Among these active materials, retinol is of interest because of its excellent anti-wrinkle effect, but its use is extremely limited as one of the most unstable components easily destroyed by light, heat, air, moisture, and the like. Specifically, methods for stabilizing retinol in formulations to overcome this limitation are described in European Patent Nos. 440398 and WO 93/00085 to stabilize retinol in oil-in-water emulsion form by adding antioxidants and chelating agents. It is. In addition, US Pat. No. 5,851,538 proposes porous microparticles as a method for improving the stability of retinol and reducing skin irritation. In addition, US Pat. No. 6,183,774 describes a method for stabilizing retinol using cationic liposomes, and US Pat. No. 5,985,296 describes a method for stabilizing retinol using cyclodextrins. In addition, US Pat. No. 6,565,886 describes a method for stabilizing retinol using alkylene adipate nanocapsules.

However, although the conventional method improves the stability of retinol, it is not yet satisfactory, and there is an urgent need for the invention of a system that can be widely used for stabilizing useful oils other than retinol.

Thus, the present inventors studied a method for stabilizing the oil-soluble active material in the polymer particles as a method for stabilizing a variety of oil-soluble active material, the emulsion polymerization of a monomer having a cation group and a monomer that can function as a capsule wall The present invention has been completed by discovering that a random copolymer can be prepared, and an active substance can be effectively introduced into the random copolymer to prepare a water dispersible cationic polymer nanocapsules to stabilize a useful active ingredient.

Accordingly, it is an object of the present invention to provide a water dispersible cationic polymer nanocapsules capable of completely stabilizing oil-soluble actives.

In addition, another object of the present invention to provide a method for producing the nanocapsules.

Another object of the present invention is to provide a cosmetic composition containing the capsule, which retains the efficacy of the oil-soluble active substance for a long time.

In order to achieve the above object, the water-dispersible cationic polymer nanocapsules of the present invention comprises the steps of: (1) polymerizing a hydrophobic polymer having a cationic functional group that can adsorb the active material; And (2) dissolving the hydrophobic polymer and oil-soluble active ingredient in step (1) in an organic solvent and then mixing the water phase and the organic phase while stirring to prepare an emulsion, and evaporating the organic phase to collect the oil-soluble active ingredient present in the water phase. Preparing a nanocapsules; characterized in that to produce a water-dispersible cationic polymer nanocapsules carrying the active ingredient as an active ingredient.

Hereinafter, the present invention will be described in more detail.

In general, a method of using polymer particles as a method for stabilizing an unstable oil-soluble active material has been widely studied. However, simply encapsulating the oil-soluble active substance in the polymer particles does not completely stabilize the active substance, especially when the particles are used in a formulation such as cosmetics, the polymer swells by water, surfactants, oils, etc. in the formulation. As a result, the unstable active material may have a problem such as slowly flowing out to the outside for a long time.

Accordingly, in the present invention, by adsorbing and trapping the oil-soluble active substance into the cationic functional group introduced into the moiety in the polymer particles, the hydrogen bond between the cationic group and the oil-soluble active component is induced, thereby immobilizing the active ingredient. It uses a double stabilization system that stabilizes in capsules to prevent the outflow of active ingredients and once again stabilizes in particles by outer polymer walls.

Hereinafter, the method of preparing the water-dispersible cationic polymer nanocapsules of the present invention will be described in detail for each step.

(1) polymerizing a hydrophobic polymer having a cationic functional group capable of adsorbing an active substance:

In the present invention, the polymerization of the polymer having a cationic functional group uses an emulsion-free emulsion polymerization method.

Monomers used to impart cationic functional groups are cationic monomers capable of radical polymerization, specifically 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, acrylamide, (meth) acrylamide, vinylpy Ralidone, vinyl-N-methylpyridinium chloride, 3-methacrylyl-2-ethyl-tetraalkyl ammonium chloride, methacrylyl-3-hydroxypropyltrimethyl ammonium chloride, acrylyl-2-ethyl- Tetraalkyl ammonium chloride, acrylyl-3-propyl-tetraalkyl ammonium chloride, 3-methacrylyl-2-hydroxypropyltrimethyl ammonium chloride, methacrylyl-3-propyltetraalkyl ammonium chloride, (meth Chlorochloryl) ethyl dimethylamine and the like. The monomer is added in an amount of 0.1 to 30% by weight based on the total weight of the entire polymer, which is not formed when the cationic group is added in less than 0.1% by weight, the dispersion nanoparticles are not formed, when added in excess of 30% by weight There is a problem in that the monomer is diffused into the water phase to lower the yield.

The initiator used in the present invention is a cationic initiator, specifically 2,2 'azobis (N, N'-dimethylene isobutyl amidine) dihydrochloride, 2,2'- azobis (2-methyl Propion amidine) dihydrochloride, 2,2'-azobis (2-amidinepropane) dihydrochloride, 2,2'-azobis-2methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propine-amide, 2,2'-azobis-2methyl-N- [1,1'-bis- (hydroxymethyl) -ethyl] propine-amide, 2,2 ' Azo compounds such as azobis (isobutylamide) dihydrate and the like. The initiator is 0.9 to 1.1% by weight relative to the total polymer content, and it is difficult to expect an effective starting effect at the following concentrations, at the above concentration tends to decrease the stability of the system due to excessive increase in the polymerization rate.

Hydrophobic monomers used for polymerization in the present invention is a monomer capable of radical polymerization, specifically, styrene, p- or m-methylstyrene, p- or m-ethylstyrene, p- or m-chlorostyrene, p- or m-chloromethylstyrene, styrenesulfonic acid, p- or mt-butoxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylic Latex, 2-hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, di Ethyl amino ethyl (meth) arc There may be mentioned acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl ether, allyl butyl ether, allyl glycidyl naphthyl ether, (meth) acrylonitrile, acrylamide, (meth) acrylate and the like.

(2) preparing a water dispersible cationic polymer nanocapsules containing the oil-soluble active substance:

The preparation method of the water-dispersible cationic polymer nanocapsules according to the present invention used a general nano precipitation method, and includes the following steps.

The oil-soluble active ingredient and the cationic polymer prepared in step (1) above are dissolved in a suitable organic solvent, i.e., a highly volatile solvent (generally alcohol / acetone) which can be mixed with water and is non-toxic and has a lower vapor pressure than water. Steps, mixing the aqueous phase with the organic phase with stirring at a suitable rate to produce an emulsion by self-association, and evaporating the organic phase to present in the aqueous phase It consists of preparing the active ingredient-supported nanocapsules.

Supported oil-soluble active substances include retinol, retinyl acetate, retinyl palmitate, α-tocopherol, tocopherol acetate, tocopherinoleate, tocopheryl nicotinate, linoleic acid, coenzyme Q-10, resveratrol , Plant extract essential oils, ursolic acid, oleanolic acid, oil soluble licorice, lipoic acid and the like.

A cosmetic composition capable of retaining the efficacy of the oil-soluble active substance for a long time is prepared by containing the water-dispersible cationic polymer nanocapsules of the present invention prepared by the above method in a cosmetic composition.

The cosmetic composition according to the present invention is not particularly limited in the formulation, but is, for example, softening longevity, nourishing longevity, massage cream, nourishing cream, pack, gel, essence, lipstick, makeup base, foundation, lotion, ointment, gel Formulations such as creams, patches and sprays.

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited only to the following example.

Example 1

A random copolymer having a cationic functional group is prepared by the following procedure. 75% by weight of butyl methacrylate and 25% by weight of (methacrylyl) ethyl dimethylamine were mixed. The mixture was added to an aqueous solution containing 0.5% by weight of 2,2'-azobis (2-methylpropionamidine) dihydrochloride, and polymerized at 250 rpm for 4 hours at 70 ° C under a nitrogen atmosphere to polymerize the polymer latex. Got. The prepared polymer is precipitated with sodium chloride to obtain a powder form, the unreacted monomer is removed through recrystallization with acetone / water, and once again precipitated with sodium chloride to obtain a powder form, followed by water after filtration. The washing process was repeated several times and dried in a vacuum oven to obtain a capsule in powder form.

Next, 2g and 1g of RETINOL 50C (produced by BASF) polymer having a cationic functional group prepared by the above process was dissolved in 100 ml of ethanol to prepare a nanocapsule carrying a retinol. In addition, 200 ml of distilled water was introduced into a round bottom flask and stirred, and the prepared polymer / retinol / ethanol mixture solution was added to obtain a self-assembly. Got.

Example 2

Capsules were prepared in the same manner as in Example 1, except that oil-soluble licorice was used as the active substance.

Example 3

Capsules were prepared in the same manner as in Example 1, except that coenzyme Q-10 was used as the active substance.

Comparative Example 1

Except that butyl methacrylate was not introduced during the polymer polymerization, it was prepared in the same manner as in Example 1.

<Test Example 1>

The morphology of the cationic polymer nanoparticles having the ideal structure prepared in Example 1 was observed using a transmission electron microscope (TEM). The results are shown in Figure 1 below.

From the results of FIG. 1, it was confirmed that the polymer nanocapsules prepared in Example 1 were produced as spherical polymer particles.

[Formulation Example 1 and Comparative Formulation Example 1]

Formulation Example 1 and Comparative Formulation Example 1 were prepared in a solubilized formulation in the form of a transparent gel with the composition of Table 1 below. The viscosity of the formulation is about 4,000 cps. In addition, the viscosity was measured at 30 degreeC and 12 rpm using Brookfield (LVDVII +).

Component (Content; Weight%) Formulation Example 1 Comparative Formulation Example 1 glycerin 5 5 Propylene glycol 4 4 Nanocapsule dispersion of Example 1 5 - Nanocapsule dispersion of Comparative Example 1 - 5 ethanol 10 10 Sodium Polyacrylate 0.5 0.5 antiseptic Quantity Quantity Purified water to 100 to 100

Formulation Example 2 and Comparative Formulation Example 2

Formulation Example 2 and Comparative Formulation Example 2 of the emulsifier type were prepared in the compositions of Table 2 below. Each oil phase and water phase were completely dissolved at 70 ° C. and emulsified at 7,000 rpm for 5 minutes to prepare a lotion in the form of an opaque gel. The viscosity of the lotion is about 2,500 cps.

Component (Content; Weight%) Formulation Example 2 Comparative Formulation Example 2 Paid Stearic acid 2 2 Cetyl alcohol 2 2 Lanolin alcohol 2 2 Liquid paraffin 7 7 Cyclomethicone 5 5 Polyoxyethylene monooleic acid ester 2 2 Preservatives, Antioxidants Quantity Quantity  Awards Glycerin 3 3 3 Propylene glycol 5 5 Triethylamine One One Nanocapsule Dispersion of Example 1 10 - Nanocapsule Dispersion of Comparative Example 1 - 10 Sodium Polyacrylate 0.15 0.15 Purified water to 100 to 100

Formulation Example 3 and Comparative Formulation Example 3

Formulation Example 3 and Comparative Formulation Example 3 of the cream formulation was prepared with the composition of Table 3 below. The manufacturing process is the same as in Formulation Example 2.

Ingredients (content; weight percent) Formulation Example 3 Comparative Formulation Example 3 Paid Beads wax 2 2 Stearyl alcohol 5 5 Stearic acid 8 8 Squalane 10 10 Propylene Glycol Monostearate 3 3 Polyoxyethylene cetyl ether One One Preservatives and Antioxidants Quantity Quantity  Awards Propylene glycol 8 8 glycerin 4 4 Triethylamine One One Nanocapsule Dispersion of Example 1 10 - Nanocapsule Dispersion of Comparative Example 1 - 10 Purified water  to 100  to 100

<Test Example 2>

In order to check the stabilization ability of the capsules prepared, Formulation Example 1 and Comparative Formulation Example 1 were stored in an oven at room temperature and 40 ° C., respectively, and samples were taken after a certain period of time to measure the amount of the remaining active substance using liquid chromatography. It was. The results are shown in Table 4.

capsule Storage temperature (℃) Initial concentration retention (%) 1 day later 7 days later 14 days later 28 days later Retinol-containing capsule of Example 1 (Formulation Example 1) Room temperature 100 100 100 100 40 100 100 100 100 Retinol-containing capsule of Comparative Example 1 (Comparative Formulation Example 1) Room temperature 100 95 92 89 40 100 92 89 78 Direct retinol Room temperature 98 95 88 63 40 89 65 52 33

As can be seen in Table 4, it was found that the retinol present in the cationic polymer capsule in the solubilized formulation of Formulation Example 1 has excellent stability.

<Test Example 3>

In order to examine the stabilization effect of the prepared emulsion type, Formulation Example 2 and Comparative Formulation Example 2 were stored in an oven at room temperature and 40 ° C., respectively, and the samples were taken after a certain period of time. Was measured. The results are shown in Table 5 below.

capsule Storage temperature (℃) Initial concentration retention (%) 1 day later 7 days later 14 days later 28 days later Retinol-containing capsule of Example 1 (Formulation Example 2) Room temperature 100 100 100 100 40 100 100 100 96 Retinol-containing capsule of Comparative Example 1 (Comparative Formulation Example 2) Room temperature 100 96 90 80 40 99 92 83 75 Direct retinol Room temperature 99 92 85 61 40 88 66 55 38

As can be seen in Table 5, even in the emulsion formulation of Formulation Example 2 it can be seen that the retinol present in the nanocapsule has excellent stability. Through this, the water-dispersible cationic polymer nanocapsules according to the present invention trap the retinol which is an active substance as a cationic functional group to maintain the chemical structure and prevent the outflow of the retinol outside the capsule to block the external harmful environment by the polymer matrix. The superiority of the stabilization system was confirmed.

<Test Example 4>

In order to confirm the stability of the prepared cream formulation, the samples of Formulation Example 3 and Comparative Formulation Example 3 were stored in an oven at room temperature and 40 ° C., respectively, and the samples were taken after a certain period of time to obtain residual active substances using liquid chromatography. The amount was measured. The results are shown in Table 6 below.

capsule Storage temperature (℃) Initial concentration retention (%) 1 day later 7 days later 14 days later 28 days later Retinol-containing capsule of Example 1 (Formulation Example 3) Room temperature 100 100 100 100 40 100 100 99 98 Retinol-containing capsule of Comparative Example 1 (Comparative Formulation Example 3) Room temperature 100 98 92 88 40 93 97 85 79 Direct retinol Room temperature 98 93 78 60 40 85 67 51 40

As can be seen in Table 6, the cream formulation, like the lotion formulation, it was confirmed that the cationic group has a significant contribution to stabilization of the retinol in the formulation.

<Test Example 5>

In order to confirm the degree of stabilization of the other active substance in the present invention, after preparing the Example 2 and 3 to Formulation Example 3 instead of Example 1, the stability was confirmed by the same method as in Test Example 4. . The results are shown in Table 7 below.

capsule Storage temperature (℃) Initial concentration retention (%) 1 day later 7 days later 14 days later 28 days later Formulations Containing Nanocapsules of Example 2 Room temperature 100 99 99 100 40 100 99 97 96 Formulations Containing Nanocapsules of Example 3 Room temperature 100 100 99 99 40 100 98 96 94

As can be seen in Table 7, it was confirmed that the present cationic polymer nanocapsule has an excellent effect on stabilization of other useful components.

From the above results, the retinol in the simple polymer particles was in contact with the external environment due to swelling of the particles by moisture, oil, surfactant, etc. in the cosmetic formulation, and did not show excellent stability. In addition, the cationic polymer nanocapsules prepared in comparison with 1 were superior to other systems in the formulation by stabilizing the chemical structure of the retinol by the polymer particle cationic group and increasing the capturing ability through adsorption to prevent the outflow of the capsule. Although stable, the cationic polymer nanocapsules prepared in Example 1, together with the internal cationic group immobilizing the retinol, significantly reduce the swelling of the particles due to moisture or oil in the formulation by the polymer matrix wall. It has been found to block external stimuli more effectively.

As described above, the cationic polymer nanocapsules according to the present invention can provide an effective stabilizing material to maintain the initial activity of the active ingredient at the nanometer size particle level that can maximize the efficacy of the active ingredient as it is have. In addition, it is possible to simplify the manufacturing process of the polymer nanocapsules for active ingredient delivery by a differentiated short process.

Claims (7)

(1) polymerizing a hydrophobic polymer having a cationic functional group capable of adsorbing an active substance; And (2) After dissolving the hydrophobic polymer and oil-soluble active ingredient in step (1) in an organic solvent and mixing the water phase and the organic phase while stirring, the emulsion is prepared, and the organic phase is evaporated to collect the oil-soluble active ingredient present in the water phase. Preparing a capsule; Method for producing a water-dispersible cationic polymer nanocapsules carrying an oil-soluble active ingredient comprising a. The method of claim 1, wherein the monomer used to impart the cationic functional group in step (1) is a cationic monomer capable of radical polymerization, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, acrylamide, (Meth) acrylamide, vinylpyrrolidone, vinyl-N-methylpyridinium chloride, 3-methacrylyl-2-ethyl-tetraalkyl ammonium chloride, methacrylyl-3-hydroxypropyltrimethyl ammonium chloride, Acrylonitrile-2-ethyl-tetraalkyl ammonium chloride, acrylyl-3-propyl-tetraalkyl ammonium chloride, 3-methacrylyl-2-hydroxypropyltrimethyl ammonium chloride, methacrylyl-3-propyl Tetraalkyl ammonium chloride, and (methacrylyl) ethyl dimethylamine is selected from the group consisting of a method for producing a water-dispersible cationic polymer nanocapsules. 3. The method of claim 2, wherein the monomer is used in an amount of 0.1 to 30% by weight based on the total weight of the entire polymer. According to claim 1, wherein the hydrophobic monomer used in the polymerization in step (1) is a monomer capable of radical polymerization, styrene, p- or m-methyl styrene, p- or m-ethyl styrene, p- or m- Chlorostyrene, p- or m-chloromethylstyrene, styrenesulfonic acid, p- or mt-butoxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl ( Meta) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, ste Aryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth ) Acrylate, diethylaminoethyl (meth) ) Acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl ether, allyl butyl ether, allyl glycidyl ether, alkyl (meth) acrylamide, and (meth) acrylonitrile. Method for producing a water-dispersible cationic polymer nanocapsules. According to claim 1, wherein the active material of step (2) is retinol, retinyl acetate, retinyl palmitate, α-tocopherol, tocopheryl acetate, tocopheryl linoleate, tocopheryl nicotinate, linoleic acid, A method for preparing a water-dispersible cationic polymer nanocapsule, characterized in that selected from the group consisting of coenzyme Q-10, resveratrol or plant extract essential oils, ursolic acid, oleanolic acid, oil-soluble licorice and lipoic acid. Dispersed cationic polymer nanocapsules prepared by the method of claim 1 to claim 5. Cosmetic composition containing the water dispersion cationic polymer nanocapsules of claim 6.

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