HK1243920A1 - Dispersion solution containing solid lipid microparticles of surfactant-free system, and cosmetic composition using same - Google Patents

Abstract

The present invention relates to a dispersion solution containing solid lipid microparticles of a surfactant-free system, and a cosmetic composition using the same, and provides: a dispersion solution containing solid lipid microparticles having improved temperature stability and an excellent appearance quality in accordance with the remarkable deterioration of thermal behavior of the solid lipid microparticles in a specific combination; and a cosmetic composition using the same.

Description

Surfactant-free dispersion liquid containing solid lipid microparticles and cosmetic composition using same

Technical Field

The present invention relates to a dispersion containing solid lipid particles in a surfactant-free system and a cosmetic composition using the same, and more particularly, to a dispersion containing solid lipid particles having high stability (even at high temperature) and excellent appearance quality and a cosmetic composition using the same.

Background

Solid Lipid Nanoparticles (SLNs), Nanostructured Lipid Carriers (NLCs), etc. have been developed as alternative carrier systems for emulsions, liposomes, and polymeric nanoparticles. The advantage of these materials is that they can increase the bioavailability of the active ingredient in the skin and the physical stability of the topical agents, while increasing the chemical stability of the active ingredient and the skin hydration by occlusion, so that these materials are recently gaining tremendous popularity in the cosmetic field. However, SLN and NLC are excessively stable, and thus it takes a long time to release the drug. To overcome this problem, a method of effectively releasing the drug is also required, and in the case of applying SLN and NLC to an oil-in-water type formulation, it may be difficult to ensure stability due to imbalance of oil-wax-lipid combination.

Therefore, in order to solve the above problems, the present applicant has searched for a dispersion containing solid lipid particles in a specific combination in which the structural change according to temperature is small, and has found that in the case where the crystal melting temperature and the recrystallization temperature are within a specific range, a dispersion containing solid lipid particles having significantly improved high-temperature stability can be prepared, thereby completing the present invention.

Disclosure of Invention

Technical problem

An object of the present invention is to provide a cosmetic composition using a dispersion containing solid lipid particles whose high-temperature stability is ensured to have various appearances and an excellent effect of improving skin moisturizing ability.

Technical scheme

In one general aspect, there is provided a dispersion containing solid lipid particles comprising a wax, a lipid, and an oil and satisfying the following inequalities 1 and 2.

[ inequality 1]

40<Tm₁<80

[ inequality 2]

28<Tm₂<55

In the inequality 1 or 2,

Tm₁is the maximum temperature value of the melting temperature of the crystal when heated; and is

Tm₂Is the highest temperature value of the recrystallization temperature upon cooling.]

In another general aspect, there is provided a cosmetic composition containing a dispersion satisfying inequalities 1 and 2 and having significantly improved high temperature stability.

Advantageous effects

The dispersion containing solid lipid particles according to the present invention has excellent emulsion stability and formation stability depending on temperature, despite being a surfactant-free system, so that the dispersion is advantageous in that the dispersion can be effectively applied to a hydrogel matrix, has excellent stability in the skin, and minimizes skin problems.

Further, the dispersion containing solid lipid particles according to the present invention can have various appearances by effectively inhibiting coalescence or aggregation, provide excellent gloss in addition to excellent spreadability when melted at skin temperature, and provide high moisturizing ability and soft feeling to the skin by excellent occlusion when the dispersion is applied to the skin.

Furthermore, the dispersion containing solid lipid particles according to the present invention can provide both excellent water-containing texture, which is an advantage of solubilized formulations, and oily texture and long-lasting moisturizing effect, which is an advantage of emulsion formulations.

The cosmetic composition containing the dispersion containing solid lipid particles according to the present invention may have a function of increasing or decreasing skin absorption through phase transition, thereby making it possible to provide a cosmetic composition optimized in skin absorption tendency.

Drawings

Fig. 1 shows the results of analysis of solid lipid particles in the composition in example 1 using Differential Scanning Calorimetry (DSC).

Fig. 2 shows the results of analysis of solid lipid particles in the composition in example 7 using Differential Scanning Calorimetry (DSC).

Fig. 3 shows the results of analysis of solid lipid particles in the composition in example 9 using Differential Scanning Calorimetry (DSC).

Fig. 4 shows the results of analysis of solid lipid particles in the composition in example 10 using Differential Scanning Calorimetry (DSC).

Fig. 5 shows the results of analysis of solid lipid particles in the composition in example 11 using Differential Scanning Calorimetry (DSC).

Fig. 6 shows the results of analysis of solid lipid particles in the composition in example 12 using Differential Scanning Calorimetry (DSC).

Fig. 7 shows the results of analysis of solid lipid particles in the composition in example 13 using Differential Scanning Calorimetry (DSC).

Fig. 8 shows the results of analysis of solid lipid particles in the composition in comparative example 1 using Differential Scanning Calorimetry (DSC).

Fig. 9 is a photograph for confirming the recovering ability of the dispersions prepared in example 7 and comparative example 1.

Detailed Description

Hereinafter, the dispersion containing solid lipid particles in a surfactant-free system and the cosmetic composition using the same according to the present invention will be described in detail. Here, unless otherwise defined, technical and scientific terms used in the present specification have general meanings understood by those skilled in the art to which the present invention belongs, and descriptions of known functions and configurations that unnecessarily obscure the gist of the present invention will be omitted in the following description.

When the Solid Lipid Nanoparticles (SLNs), the Nanostructured Lipid Carriers (NLCs), and the like according to the related art are applied to a cosmetic composition, since the SLNs and the NLCs do not endure the change with time according to the temperature, the wax or the lipid may be recrystallized at a low temperature or melted at a high temperature, so that there are problems such as poor feeling in use and deterioration in stability due to a decrease in the viscosity of the formulation, and generation of turbidity in the formulation.

Accordingly, the present applicant has conducted further studies on the structural changes of the respective components contained in the solid lipid particles according to the temperature change by DSC, and as a result, the present applicant has found that a dispersion having improved stability can be prepared due to the deterioration of the thermal behavior of the solid lipid particles in a specific combination. The dispersion satisfies inequalities 1 and 2 below, and contains solid lipid particles containing wax, lipid, and oil.

[ inequality 1]

40<Tm₁<80

[ inequality 2]

28<Tm₂<55

In the inequality 1 or 2,

Tm₁is the maximum temperature value of the melting temperature of the crystal when heated; and is

Tm₂Is the highest temperature value of the recrystallization temperature upon cooling.]

The dispersion containing solid lipid particles according to an exemplary embodiment of the present invention, which is a stable dispersion with ensured stability, may have various appearances, visually recognized effects are manifested by allowing the active ingredient to be absorbed by the skin, and the dispersion may be in a surfactant-free system, so that the dispersion may minimize skin irritation or skin problems due to the surfactant according to the related art. Thus, the dispersion can also be applied to products for sensitive skin.

As used herein, the term "lipid" refers to a single-chain lipid, and specific examples thereof may include at least one selected from linear saturated alcohols, linear saturated fatty acids, and the like, but are not limited thereto.

Further, as used herein, the term "full width at half maximum" refers to the temperature variation range (△ T) based on half of the height relative to the peak of the crystal melting temperature and recrystallization temperature by DSC analysis.

In order for the dispersion to be gently applied to the skin when melted at skin temperature and to impart excellent gloss and moisture feel to the skin, preferably, the crystal melting temperature Tm upon heating according to the present invention₁The following inequality 3 may be satisfied, but is not limited thereto.

[ inequality 3]

40<Tm₁<80

Further, in view of achieving improved high-temperature stability and transparency of the external phase due to the rapid recovery ability, the recrystallization temperature Tm upon cooling according to the present invention₂The following inequality 4 may be satisfied, but is not limited thereto.

[ inequality 4]

28<Tm₂<40

Advantageously, the crystal melting temperature and the recrystallization temperature of the dispersion according to the exemplary embodiment of the present invention each have a single peak, and the distribution of the crystal melting temperature and the recrystallization temperature is small. The distribution of the crystal melting temperature and the recrystallization temperature is small, which may mean that the structural change according to the temperature change is small, and thus the low and high temperature stability of the solid lipid particle may be significantly improved.

In this regard, the full width at half maximum △ Tm of the melting temperature of the crystal upon heating₁Full width at half maximum △ Tm with a small distribution or recrystallization temperature on cooling in the range of 1 to 5 ℃₂Having a small distribution in the range from 1 to 5 ℃ in view of the dispersionFurthermore, in view of the excellent ability to recover solid lipid particles when the temperature is lowered from a high temperature (45 ℃ or higher) to room temperature, the full width at half maximum △ Tm of the recrystallization temperature during cooling₂It is required to be in the range of 1 to 5 deg.c.

The solid lipid particle according to an exemplary embodiment of the present invention may include at least one wax selected from the group consisting of a vegetable wax, an animal wax, a mineral wax, and a synthetic wax. Non-limiting examples of the wax may include at least one selected from the group consisting of: vegetable waxes including candelilla wax, carnauba wax, rice wax, cotton wax, berry fruit wax, insect wax, sugar cane wax, jojoba wax, shea butter, sunflower seed wax, hydrogenated vegetable oils, hydrogenated olive oil octadecyl esters, hydrogenated olive oil dodecyl esters, and the like; animal waxes including beeswax and lanolin; mineral waxes including ozokerite, microcrystalline, Multiwax (Multiwax), and paraffin waxes, etc.; and synthetic waxes including polyethylene wax, Polyoxyethylene (POE) lanolin alcohol ether wax, POE lanolin alcohol acetate wax, POE cholesterol ether wax, lanolin fatty acid polyethylene glycol wax, POE hydrogenated lanolin alcohol ether wax, and the like, but not limited thereto. In view of simultaneously providing an excellent oily texture and a long-lasting moisturizing effect in addition to the stability of the solid lipid particles, it is preferred that the wax is a wax in a temperature range of 50 to 80 ℃. More preferably, the wax comprises at least one wax selected from the group consisting of: vegetable waxes including candelilla wax, carnauba wax, rice wax, berry pulp wax, jojoba wax, shea butter, sunflower seed wax, hydrogenated olive oil stearyl ester, and hydrogenated olive oil lauryl ester, and the like; mineral waxes including microcrystalline waxes, multisolids, and paraffins, among others; and synthetic waxes including polyethylene wax and the like.

The oil may be at least one oil selected from hydrocarbon oils, ester oils, triglyceride oils, vegetable oils and silicone oils. As non-limiting examples of oils, selected from hydrocarbon oils including squalane, mineral oil, hydrogenated polydecene, hydrogenated polyisobutene, and the like; ester oils including isopropyl palmitate, 2-octyldodecyl myristate, isopropyl myristate, butyl octyl salicylate, cetyl octanoate, cetyl octyl hexanoate, coconut oil octanoate/decanoate, decyl cocoate, isostearyl isostearate, pentaerythritol tetraethylhexanoate, dioctyl carbonate, and the like; vegetable oils, including castor oil, olive oil, jojoba oil, avocado oil, macadamia nut oil, meadowfoam seed oil, and the like; and silicone oils including oils in dimethylpolysiloxane, methylphenylpolysiloxane, decamethylcyclopentasiloxane, methyltrimethylpolysiloxane, phenyltrimethylpolysiloxane, cyclomethicone, polydimethylsiloxane, etc. may be used alone or a mixture thereof may be used, but the oils are not limited thereto. In view of excellent feeling of use and low solubility in wax or lipid, it is preferable to use a wax selected from vegetable oils including jojoba oil, avocado oil, meadowfoam seed oil, and the like; hydrocarbon oils such as squalane, hydrogenated polydecene, hydrogenated polyisobutene, and the like; ester oil, including 2-octyl dodecyl myristate, cetyl octyl caproate, isopropyl myristate, butyl octyl salicylate, pentaerythritol tetraethyl caproate, and dioctyl carbonate. Here, the melting point of the dispersion may decrease as the solubility of the oil in the wax or lipid increases, and the melting point of the dispersion increases as the solubility decreases. In view of achieving a desired melting point, it is preferable to use the straight-chain hydrocarbon oil as described above.

In addition, the lipid may be at least one selected from the group consisting of higher fatty alcohols having 10 to 30 carbon atoms and higher fatty acids having 10 to 30 carbon atoms, and it is preferable to use higher fatty alcohols having 10 to 30 carbon atoms in view of the possibility that the lipid has high solubility in oil and is gently applied to the skin while melting at the skin temperature. Here, non-limiting examples of the higher aliphatic alcohol may include at least one selected from the group consisting of cetyl alcohol, stearyl alcohol, cetyl/stearyl alcohol, behenyl alcohol, and the like, but are not limited thereto.

The solid lipid particle according to an exemplary embodiment of the present invention may include 50 to 150 parts by weight of the lipid and 100 to 500 parts by weight of the oil, based on 100 parts by weight of the wax, and preferably the wax, the lipid and the oil are mixed in a ratio of 1: 1: 2 to 1: 1: 5 (wax: lipid: oil) are mixed with each other.

The aqueous phase is an external phase of the dispersion according to an exemplary embodiment of the present invention, and may further contain an aqueous phase thickener for stably dispersing the solid lipid particles. In this case, as the aqueous phase thickener, any substance can be used without limitation as long as it is used to increase the viscosity of the aqueous phase. However, the aqueous phase thickener may comprise at least one aqueous phase thickener selected from the group consisting of: polyacrylic acid, polyacrylamide, polymethacrylic acid, polyhydroxyethylmethacrylate, polyacrylic acid-polymethacrylic acid copolymer, polyacrylic acid-polyacrylamide copolymer, polymethacrylic acid-polyacrylamide copolymer, polyethylene glycol, poly (N, N-ethylaminoethylmethacrylate), hyaluronic acid, agar, chitosan, ammonium acryloyldimethyltaurate-VP copolymer, xanthan gum, cellulose ether, polyvinyl derivative, alginate, polyacrylate, etc., or an aqueous phase thickener substituted with a hydrophobic group. In order to have low emulsifying activity, improve the stability of the formulation and the transparency of the product, and have excellent recovery characteristics, it is preferable that the aqueous phase thickener is polyacrylic acid; polyacrylamide; and polymethacrylic acid which is not substituted by hydrophobic groups, or a copolymer of the two.

The viscosity of the dispersion according to the exemplary embodiment of the present invention is preferably in the range of 10000 to 50000 cps. In view of stable dispersibility and excellent spreadability of the solid lipid particles, the viscosity is preferably in the range of 10000 to 30000cps, but is not limited thereto.

In addition, the average diameter of the solid lipid particles may be in the range of 10nm to 20mm or 50nm to 10 mm. In order to have phase stability according to temperature and optimum stability, the average diameter may be in the range of 100nm to 10mm, but is not limited thereto.

The present invention provides a cosmetic composition containing a dispersion satisfying the following inequalities 1 and 2.

[ inequality 1]

40<Tm₁<80

[ inequality 2]

28<Tm₂<55

In the inequality 1 or 2,

Tm₁is the maximum temperature value of the melting temperature of the crystal when heated; and is

Tm₂Is the highest temperature value of the recrystallization temperature upon cooling.]

The cosmetic composition contains a dispersion satisfying the above range, so that the cosmetic composition can provide excellent gloss in addition to fresh spreadability while melting at skin temperature, and can provide high moisturizing ability and soft feeling to the skin through excellent occlusion when the cosmetic composition is applied to the skin.

In addition, the cosmetic composition may have a function of increasing or decreasing skin absorption through phase transition, thereby making it possible to provide a cosmetic composition in which the skin absorption tendency is optimized.

The cosmetic composition according to the exemplary embodiment of the present invention may further include a perfume, a pigment, a preservative, a bactericide, an oxidation stabilizer, a pearlescent agent, and the like within a range that does not inhibit the effect of the dispersion.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are for illustrating the present invention, but the present invention is not limited thereto.

(examples 1 to 15 and comparative example 1)

After an oil phase was prepared by completely dissolving wax, lipid and oil at 85 c according to the compositions shown in tables 1 and 2 below, a thickener having the following composition was injected thereto, and the resultant was injected into a pre-formed aqueous phase (aqueous phase gel matrix) to have a viscosity of 15000cps (centipoise), and then stirred at room temperature using a stirrer, thereby respectively preparing dispersions having solid lipid particles (average diameter: 3 mm).

(Table 1)

(Table 2)

Differential Scanning Calorimetry (DSC) analysis of solid lipid particles containing a dispersion of solid lipid particles was performed in examples 1 to 15 and comparative example 1 under the following conditions, and the results are shown in fig. 1 to 9.

(DSC analysis conditions)

A differential scanning calorimeter (4100DSC, manufactured by Calorimeter Science Corporation (CSC), Lindon, Utah, United States) was used. One pan not filled with the sample was used as a reference pan, and the other pans were filled with samples of each solid lipid particle prepared in examples 1 to 15 and comparative example 1, respectively, and then subjected to DSC measurement. The heat flow of the reference plate not filled with sample was set as baseline and the heat flow of the other samples was compared. The temperature range measured was 25 ℃ to 85 ℃ and was measured at a rate of 5 ℃/min. The results are shown in fig. 1 to 8 and table 3 below.

(Table 3)

As shown in fig. 1 to 7, the crystal melting temperature and the recrystallization temperature of the solid lipid particle according to the present invention have a single peak crystal melting temperature value and a single peak of full width at half maximum satisfying the recrystallization temperature upon cooling according to the present invention, respectively, so that the crystallization speed is fast and thus the recovery ability of the solid lipid particle in the formulation is excellent.

In contrast, as shown in fig. 8, it can be understood that in comparative example 1, the solid lipid particle has a wide range of crystal melting temperature values, i.e., a large structural change according to temperature, and also has a wide range of recrystallization temperature values, so that the crystallization speed is slow.

That is, since the thermal behavior of the solid lipid particle satisfying inequalities 1 and 2 according to the present invention is minimized, the structural change according to the temperature change is suppressed, and thus, the solid lipid particle has a small distribution of the crystal melting temperature and the recrystallization temperature range. Thus, the solid lipid particle may exhibit more improved emulsion stability and excellent stability according to temperature.

Further, in order to confirm the formulation stability according to temperature, the dispersions prepared in examples 1 to 15 and comparative example 1 were respectively put into a vial (capacity: 20g) and stored at room temperature (25. + -. 2 ℃ C.) and in a cryostat (4. + -. 2 ℃ C.), a cryostat (45. + -. 2 ℃ C.) and a circulation Chamber (Freeze-Thaw Chamber, temperature cycle from-20 ℃ to 45 ℃ C., 1 cycle/day), and the formation stability of each sample was confirmed every week. The results are shown in table 4 below.

(Table 4)

◎, stable, no separation of oil or water, and recovery of solid lipid particles.

○ it is stable, no separation of oil or water, and the solid lipid particles recover but are slightly transparent.

△ relatively unstable, the oil or water separates slightly (0.1cm or less) and the solid lipid particles become transparent.

X: is remarkably unstable: the oil or water separated severely to form a layer (0.1cm or more), the solid lipid particles became transparent and the outer phase became turbid.

As shown in table 4, it can be recognized that the dispersion according to the present invention is significantly excellent in formulation stability at various temperatures as compared to comparative example 1, and as shown in fig. 9, when the dispersion is maintained at a high temperature and then at room temperature, the shape of the solid lipid particles is restored, thereby maintaining a transparent aqueous gel matrix. However, in comparative example 1, it can be recognized that the stability of the formulation according to temperature is deteriorated, and particularly the high temperature stability is significantly reduced. When the dispersion is kept at a high temperature and then at room temperature, the shape of the solid lipid particles is not restored, but is dissociated in the aqueous phase and becomes white, so that the stability of the formulation is deteriorated, and discoloration of the formulation (for example, color change to yellow (occurrence of browning)) occurs.

That is, a skin cosmetic composition can be provided by using a dispersion containing solid lipid particles having a specific composition of the present invention, which can have significantly improved low and high temperature stability, have excellent appearance quality, and impart a smooth use feeling, a soft skin texture, and improved gloss, as compared to a dispersion containing solid lipid particles according to the related art.

Claims (12)

1. A dispersion comprising solid lipid particles comprising a wax, a lipid and an oil, and satisfying the following inequalities 1 and 2,

[ inequality 1]

40<Tm₁<80

[ inequality 2]

28<Tm₂<55

In the inequality 1 or 2, the,

Tm₁is the highest temperature value of the melting temperature of the crystal during heating; and is

Tm₂Is re-knotted on coolingThe highest temperature value of the crystal temperature.

2. The dispersion of claim 1, wherein the crystal melting temperature and the recrystallization temperature each have a single peak.

3. The dispersion of claim 2, wherein the full width at half maximum △ Tm of the recrystallization temperature upon cooling₂Is 1 to 5 ℃.

4. The dispersion of claim 1, wherein the solid lipid particles comprise at least one wax selected from the group consisting of vegetable waxes, animal waxes, mineral waxes, and synthetic waxes.

5. The dispersion according to claim 4, wherein the lipid is at least one selected from a higher fatty alcohol having 10 to 30 carbon atoms and a higher fatty acid having 10 to 30 carbon atoms.

6. The dispersion according to claim 5, wherein the oil is at least one oil selected from the group consisting of hydrocarbon oils, ester oils, triglyceride oils, vegetable oils and silicone oils.

7. The dispersion of claim 4, wherein the solid lipid particles contain 50 to 150 parts by weight of lipid and 100 to 500 parts by weight of oil, based on 100 parts by weight of wax.

8. The dispersion of claim 1, further comprising an aqueous phase thickener.

9. The dispersion of claim 8, wherein the aqueous phase thickener is at least one selected from the group consisting of polyacrylic acid, polyacrylamide, polymethacrylic acid, polyhydroxyethylmethacrylate, polyacrylic acid-polymethacrylic acid copolymer, polyacrylic acid-polyacrylamide copolymer, polymethacrylic acid-polyacrylamide copolymer, polyethylene glycol, poly (N, N-ethylaminoethyl methacrylate), hyaluronic acid, agar, chitosan, ammonium acryloyldimethyltaurate-VP copolymer, xanthan gum, cellulose ether, polyvinyl derivatives, alginate, and polyacrylate.

10. The dispersion of claim 1, wherein the viscosity of the dispersion is in the range of 10000 to 50000 cps.

11. The dispersion of claim 1, wherein the solid lipid particles have an average diameter of 10nm to 20 nm.

12. A cosmetic composition comprising the dispersion according to any one of claims 1 to 11.