Cosmetic composition comprising particles containing high content of ceramide and method for preparing same

Abstract

In a cosmetic composition according to the present invention, a coating membrane with a multilayer lamella structure is formed on the outside of ceramide particles by using phytosphingosine, and therefore, the cosmetic composition is stably present without ceramide precipitation even in formulations with low viscosity as well as high viscosity although the particles contain a high content of ceramide, and a cosmetic composition showing an excellent skin barrier recovery effect can be provided.

Claims

1. A method of preparing a cosmetic composition comprising ceramide-accommodating particles, comprising: preparing ceramide-accommodating particles by mixing an oil-phase part comprising a ceramide and phytosphingosine with an aqueous phase part, wherein in the step of mixing, the oil-phase part is dispersed in the aqueous phase part by permeating the oil-phase part through an emulsification membrane to prepare the ceramide-accommodating particles, wherein the oil-phase part is included at 20 parts by weight or less with respect to 100 parts by weight of the entire composition, wherein the particles have a membrane with a multi-layered lamellar structure and a core accommodating the ceramide, and wherein the particles have an outer coating membrane formed of phytosphingosine, wherein the aqueous phase part either comprises purified water and tromethamine, or consists of purified water, C10-C30 alkyl acrylate crosspolymer, glycerin, dipropylene glycol, and 1,2-hexanediol, and wherein the ceramide is one or more selected from the group consisting of ceramide EOP, ceramide NS, ceramide NP, ceramide AS, ceramide EOS, ceramide AP, ceramide NDS, glucosylceramide, and omega-hydroxyceramide.

2. The method of claim 1, wherein the particles have an average particle diameter of 50 to 300 μm.

3. The method of claim 1, wherein the ceramide is included at 10 to 50 wt % per particle.

4. The method of claim 1, wherein the ceramide is included at 0.001 to 10 parts by weight with respect to 100 parts by weight of the entire composition.

5. The method of claim 1, wherein the phytosphingosine is included at 0.001 to 5 parts by weight with respect to 100 parts by weight of the entire composition.

6. The method of claim 1, wherein the cosmetic composition is in an oil-in-water (O/W) formulation.

7. The method of claim 1, wherein the oil-phase part further comprises one or more oil-phase ingredients selected from the group consisting of cholesterol, a neutral lipid, a fatty acid, a fatty alcohol, an oil, and a wax.

8. The method of claim 7, wherein the oil is one or more selected from the group consisting of a silicone-based wax, an ester-based oil, a hydrocarbon-based oil, and a vegetable oil.

9. The method of claim 7, wherein the wax is one or more selected from the group consisting of a hydrocarbon-based wax, a vegetable wax, and a silicone wax.

10. The method of claim 1, wherein the cosmetic composition has a viscosity of 0.1 to 40,000 cps.

11. The method of claim 1, wherein the oil-phase part is permeated through the emulsification membrane under a pressure condition of 0.1 to 100 kPa.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a set of photographs of particles prepared according to the present invention as observed through a microscope (left: optical microscope, right: polarized microscope), wherein FIG. 1A shows particles with a composition of Comparative Example 1, FIG. 1B shows particles with a composition of Comparative Example 2, and FIG. 1C shows particles with a composition of Example 1.

(2) FIG. 2 is a set of photographs of particles prepared according to the present invention as observed through an electron microscope after storage at room temperature for 4 weeks, wherein FIG. 2A shows particles with a composition of Comparative Example 1, FIG. 2B shows particles with a composition of Comparative Example 2, and FIG. 2C shows particles with a composition of Example 1.

(3) FIG. 3 is a graph illustrating the skin moisture content after application of a cosmetic composition including particles prepared according to the present invention onto the skin for 4 weeks (n=22, *p<0.05).

(4) FIG. 4 is a graph illustrating the skin barrier recovery rate of a cosmetic composition including ceramide particles according to the present invention according to a ceramide content.

MODES OF THE INVENTION

(5) Hereinafter, the present invention will be described in detail with reference to the following examples. However, it should be understood that the following examples and experimental examples proposed herein are given for the purpose of illustration only and are not intended to limit the scope of the present invention.

Example 1 and Comparative Examples 1 and 2. Preparation of Cosmetic Composition

(6) Cosmetic compositions were prepared in compositions shown in Table 1 below. Specifically, a cosmetic composition of Example 1 was prepared as follows. First, an aqueous phase part was introduced into a continuous phase tank with temperature control and stirring functions and dissolved while being heated at 40 to 60° C., and then stirring was performed at 50 to 500 rpm. In addition, an oil-phase part containing a ceramide was introduced into a dispersed phase tank and dissolved while being heated at 50 to 90° C., and then membrane emulsification was performed while applying a pressure of 0.1 to 100 kPa, thereby preparing ceramide particles. A cosmetic composition including the prepared ceramide particles was cooled to 30° C., thereby finally preparing a cosmetic composition including particles with a lipid membrane structure.

(7) Compositions of Comparative Examples 1 and 2 were prepared in the same manner as in Example 1 except that both a ceramide and phytosphingosine were not contained in an oil-phase part and phytosphingosine was not contained in an oil-phase part, respectively.

(8) TABLE-US-00001 TABLE 1 Ingredient Comparative Comparative (parts by weight) Example 1 Example 1 Example 2 Aqueous Purified water 78.8 78.8 79.1 phase Acrylate/C10-30 0.2 0.2 0.2 part alkyl acrylate crosspolymer Glycerin 5 5 5 Dipropylene glycol 5 5 5 1,2-Hexanediol 2 2 2 Oil- Caprylic/capric 1.2 3 1.2 phase triglyceride part Behenic acid 2 3 2 Behenyl alcohol 1 3 1 Cholesterol 1.5 — 1.5 Phytosphingosine 0.3 — — Ceramide NP 3 — 3 Total 100 100 100

Experimental Example 1. Confirmation of Characteristic of Ceramide Particle

(9) 1) Confirmation of Particle Form

(10) The ceramide particles prepared in Example 1 were observed using an optical microscope and a polarized microscope. FIG. 1A shows particles with a composition of Comparative Example 1 which does not contain a ceramide, FIG. 1B shows particles with a composition of Comparative Example 2 which contains typically used lipids to stabilize a ceramide, and FIG. 1C shows particles with a composition of Example 1 which further contains phytosphingosine.

(11) Referring to FIGS. 1 and 2, it can be seen that the particles not containing a ceramide (FIGS. 1A and 2A) and the particles containing a ceramide and typical lipids (FIGS. 1B and 2B) were in the form of a general lipid capsule with a monolayer structure, in which hydrophobic ingredients were simply agglomerated. In addition, in the case of Comparative Example 2, it can be seen that a wax was precipitated in the particle surface as shown in FIG. 2B.

(12) On the other hand, it can be seen that the particles containing a ceramide and phytosphingosine (FIGS. 1C and 2C) had a specific structure in which the outer surface of particles was differentiated as a shell unlike the above-described two cases and showed no precipitation of a ceramide despite a high content of ceramide as shown in FIG. 2C.

(13) 2) Confirmation of Skin Hydration Improvement Effect

(14) The cosmetic composition of Example 1 was applied onto the skin for 4 weeks, and skin hydration was measured (FIG. 3).

(15) All 22 subjects who completed this measurement were female with an average age of 47.182 years. The selected subjects had no specific skin symptoms and also had no medical history or drug history that could affect the test.

(16) For the instrument evaluation, the subjects were stabilized in a waiting room at a constant temperature and humidity of 20 to 25° C. and 40 to 60% for 30 minutes to adapt their skin surface temperatures and humidities to the environment of the measurement space, and water intake was restricted during the stabilization. For objective measurement, one researcher conducted the measurement, and the same site was measured for each measurement.

(17) The skin hydration measurement was conducted by measuring the same site of the face before and after the application of the test composition using Corneometer CM 825 (Courage+Khazaka Electronic GmbH, Germany). The measurement was conducted three times through a sensor by allowing a Corneometer probe to be brought into contact with the skin, and an average value thereof was used as the data for evaluating skin hydration. The unit is expressed by the unit constant A.U., and an increase in measurement value indicates an increase in skin hydration.

(18) As a result, it can be seen that the skin hydration was increased by about 7.93% after 2-week application of the cosmetic composition according to the present invention and increased by about 7.23% after 4-week application compared to that before the application. Therefore, the cosmetic composition according to the present invention was confirmed to help to improve skin hydration.

Examples 2 and 3 and Comparative Example 3. Preparation of Cosmetic Composition According to Ceramide Content

(19) In order to confirm transepidermal water loss (TEWL) according to a ceramide content, cosmetic compositions were prepared in compositions shown in the following Table 2. In this case, cosmetic compositions were prepared in the same manner as in Example 1 except for a ceramide content.

(20) TABLE-US-00002 TABLE 2 Ingredient Comparative (parts by weight) Example 3 Example 2 Example 3 Aqueous Purified water 75.8 74.8 69.8 phase Acrylate/C10-30 0.2 0.2 0.2 part alkyl acrylate crosspolymer Glycerin 5 5 5 Dipropylene glycol 5 5 5 1,2-Hexanediol 2 2 2 Oil- Caprylic/capric 2.4 2.4 2.4 phase triglyceride part Behenic acid 3.6 3.6 3.6 Behenyl alcohol 2.4 2.4 2.4 Cholesterol 3 3 3 Phytosphingosine 0.6 0.6 0.6 Ceramide NP 0 1 6 Total 100 100 100

Experimental Example 2. Confirmation of Skin Barrier Recovery Rate

(21) The cosmetic composition was applied onto a damaged skin model for 3 days while varying a ceramide content, and TEWL was measured to confirm a skin barrier recovery rate.

(22) All 5 subjects of this experiment were female with an average age of 29.2 years. The selected subjects had no specific skin symptoms and also had no medical history or drug history that could affect the test.

(23) In this test, a 1% SLS patch was attached to the left forearm of the subject to induce skin irritation. The same researcher induced skin irritation for 24 hours by attaching a patch to the designated test site, then evaluated the presence or absence of skin irritation, and conducted instrument measurement for a site to which the test composition was applied and a site to which it was not applied.

(24) For the instrument evaluation, the subjects were stabilized in a waiting room at a constant temperature and humidity of 20 to 25° C. and 40 to 60% for 30 minutes to adapt their skin surface temperatures and humidities to the environment of the measurement space, and water intake was restricted during the stabilization. For objective measurement, one researcher conducted the measurement, and the same site was measured for each measurement.

(25) The TEWL measurement was conducted by measuring the same site of the forearm before and after the application of the test composition using Tewameter TM300 (Cutometer® MPA 580, Courage+Khazaka Electronic GmbH, Germany). The same researcher measured TEWL by allowing a probe to be brought into contact with the forearm of all test subjects with the same pressure. The measurement was conducted three times through a sensor by allowing a Tewameter probe to be brought into contact with the skin, and an average value thereof was used as the data for evaluating a skin barrier recovery rate. The skin barrier recovery rate was calculated by the following equation, and a higher skin barrier recovery rate indicates that TEWL is improved by the test composition, which helps in skin barrier recovery.
Skin barrier recovery rate (%)=(TEWL after induction of skin irritation−TEWL at the time of measurement)/(TEWL after induction of skin irritation−TEWL before induction of skin irritation)×100

(26) The skin barrier recovery rate calculated using TEWL after application of the composition onto the skin is graphically shown in FIG. 4.

(27) As shown in FIG. 4, it can be seen that the cosmetic composition of Example 3, which contained 6 parts by weight of a ceramide, showed the highest skin barrier recovery on day 1, and the cosmetic compositions containing a ceramide showed further recovered skin barriers on day 3 (p<0.05). From this result, it was confirmed that the particles according to the present invention can achieve desired effects while containing a high content of ceramide.

Experimental Example 3. Confirmation of Formulation Stability

(28) The compositions prepared in Example 1 and Comparative Examples 1 and 2 were stored at varying temperatures for a long period of time, and the formulation stability thereof was confirmed. The compositions were stored at 25° C., 0° C., and 45° C. and also stored in a chamber whose temperature circulates from 0° C. to 45° C., and formulation stability against temperature change was confirmed. Results thereof are shown in the following Table 3.

(29) TABLE-US-00003 TABLE 3 Comparative Comparative Condition Example 1 Example 1 Example 2 25° C. 1 week Good Good Good 4 weeks Good Good Precipitated in needle shape 8 weeks Good Good Precipitated in needle shape 16 weeks Good Good Precipitated in needle shape 0° C. 1 week Good Good Good 4 weeks Good Good Good 8 weeks Good Good Good 16 weeks Good Good Good 45° C. 1 week Good Coagulated Coagulated and precipitated in needle shape 4 weeks Good Coagulated Coagulated and precipitated in needle shape 8 weeks Good Coagulated Coagulated and precipitated in needle shape 0° C..Math.45° C. 1 week Good Coagulated Coagulated and precipitated in needle shape 4 weeks Good Coagulated Particle surface was cracked

(30) As shown in Table 3, Comparative Example 1, which was in the form of a general lipid capsule not accommodating a ceramide, showed that particles were agglomerated (coagulated) at 45° C., and Comparative Example 2 showed agglomeration of particles, precipitation of the inner material of particles, or cracking in the particle surface at all temperatures except for 0° C. On the other hand, Example 1 of the present invention showed that particles were stably present at all temperatures.

Examples 4 to 6. Preparation of Cosmetic Composition Including Particles Containing High Content of Ceramide

(31) In order to confirm that the above-prepared cosmetic composition including particles containing a high content of ceramide is applicable regardless of viscosity, cosmetic compositions were prepared in compositions shown in the following Table 4. Specifically, cosmetic compositions of Examples 4 to 6 were prepared as follows. First, an aqueous phase part was introduced into a gum mixer and uniformly dispersed, ceramide particles finally separated from the cosmetic composition prepared in Example 2 were added, and stirring was performed for 5 minutes, thereby preparing a cosmetic composition.

(32) TABLE-US-00004 TABLE 4 Ingredient (parts by weight) Example 4 Example 5 Example 6 Aqueous Purified water 77.7 77.08 76.74 phase Acrylate/C10-30 0.15 — — part alkyl acrylate crosspolymer Carbomer — 0.46 0.3 Glyceryl acrylate/ — — 0.4 acrylic acid copolymer Ammonium — — 0.3 acryloyldimethyl- taurate/VP copolymer Trisodium EDTA 0.02 0.02 0.02 Glycerin 10 10 10 1,2-Hexanediol 2 2 2 Tromethamine 0.13 0.44 0.24 Addition Ceramide particle- 10 10 10 part containing cosmetic composition (Example 2) Total 100 100 100

Experimental Example 4. Confirmation of Formulation Stability

(33) The compositions prepared in Examples 4 to 6 were stored at varying temperatures for a long period of time, and the formulation stability thereof was confirmed. The compositions were stored at 25° C., 0° C., and 45° C. and also stored in a chamber whose temperature circulates from 0° C. to 45° C., and formulation stability against temperature change was confirmed. The viscosity was measured at 25° C. using a Brookfield viscometer (spindle #4, 30 rpm) after preparation, and results thereof are shown in the following Table 5.

(34) TABLE-US-00005 TABLE 5 Example 4 Example 5 Example 6 Viscosity (cps) 540 14,800 Not measurable Phase Liquid Lotion Cream 25° C. 1 week Good Good Good 4 weeks Good Good Good 8 weeks Good Good Good 16 weeks Good Good Good 0° C. 1 week Good Good Good 4 weeks Good Good Good 8 weeks Good Good Good 16 weeks Good Good Good 45° C. 1 week Good Good Good 4 weeks Good Good Good 8 weeks Good Good Good 16 weeks Good Good Good 0° C..Math.45° C. 1 week Good Good Good 4 weeks Good Good Good

(35) As a result, the viscosity of Example 6 exceeded 20,000 cps when measured using the same measurement standards as in Examples 4 and 5, so the measurement thereof was impossible. From this experiment, it was confirmed that the compositions of Examples 4 to 6 included well-dispersed ceramide particles and had no problem in stability regardless of viscosity.