CN113952239B

CN113952239B - Composite liquid crystal emulsifier and preparation method and application thereof

Info

Publication number: CN113952239B
Application number: CN202111135293.0A
Authority: CN
Inventors: 戴跃锋; 何广文; 颜少慰
Original assignee: Syoung Cosmetics Manufacturing Co Ltd
Current assignee: Syoung Cosmetics Manufacturing Co Ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2023-05-23
Anticipated expiration: 2041-09-27
Also published as: CN113952239A

Abstract

The invention relates to the technical field of cosmetics, in particular to a composite liquid crystal emulsifier and a preparation method and application thereof. The invention uses cetostearyl alcohol to embed the retinol propionate, and prepares the composite liquid crystal emulsifier by matching with emulsifier with specific composition. Experiments show that the embedding rate of the composite liquid crystal emulsifier for the retinol propionate reaches 90.87 percent; the polarizing microscope verifies that the capsule wall forms a liquid crystal structure; the degradation of the inner core material is 16.02% within 32 days, which proves that the system has good stability and slow release performance.

Description

Composite liquid crystal emulsifier and preparation method and application thereof

Technical Field

The invention relates to the technical field of cosmetics, in particular to a composite liquid crystal emulsifier and a preparation method and application thereof.

Background

Retinol and its derivatives refer to natural vitamin a and retinal, retinoic acid, retinol esters and other artificial synthetic products of similar structure. Has moisturizing, healing, ultraviolet radiation resisting, acne reducing, acne inhibiting, and precancerous cell converting into normal cell.

However, retinol and its esters have all-trans conjugated double bonds in structure, so that they are extremely unstable to environmental conditions such as heat, oxygen, light, etc. Under strong light irradiation and high temperature conditions, double bonds can be broken or degenerated to generate an epoxy compound without bioactivity, and depending on the conditions, reactive Oxygen Species (ROS) including singlet oxygen can be generated. Therefore, the retinol preparation needs to be protected from light and refrigerated, and the product containing the retinol component is suitable for use in the evening. In addition, retinol is more irritating.

Structural instability of retinol and its derivatives has limited the use of retinol in cosmetics. Therefore, how to reduce the direct contact stimulation of retinol to skin and the instability of retinol added into the preparation, thereby increasing the content of retinol and its derivatives in the formulation, improving the anti-aging effect of the product, and preparing an emulsifier with regular shape, uniform particle size, better protection and slow release effects is a technical problem to be solved.

Disclosure of Invention

In view of the above, the invention provides a composite liquid crystal emulsifier, and a preparation method and application thereof. The composite liquid crystal emulsifier has high embedding rate and good stability of the retinol propionate.

In order to achieve the above object, the present invention provides the following technical solutions:

a compound liquid crystal emulsifier comprises TWEEN-20, TWEEN-60 concentration, cetostearyl alcohol, retinol propionate, phenoxyethanol, ethylhexyl glycerol and water.

In some embodiments, the composite liquid crystal emulsifier comprises the following components in percentage by mass:

TWEEN-200.2-1.4%, TWEEN-600.8-5.6%, cetostearyl alcohol 6-20%, retinol propionate 0.3-0.4%, preservative 0.66% and the balance water.

The type of the preservative is not particularly limited, and can be any type commonly found in the cosmetic field. Preservatives in the present invention include, but are not limited to, phenoxyethanol and ethylhexyl glycerol.

TWEEN-200.2-0.4%, TWEEN-600.6-0.8%, cetostearyl alcohol 10-12%, retinol propionate 0.4%, phenoxyethanol 0.6%, ethylhexyl glycerol 0.06%, the balance water.

TWEEN-20 concentration 0.2%, TWEEN-60 concentration 0.8%, cetostearyl alcohol 12%, retinol propionate 0.4%, phenoxyethanol 0.6%, ethylhexyl glycerol 0.06%, the balance water.

TWEEN-20 concentration 0.4%, TWEEN-60 concentration 0.6%, cetostearyl alcohol 10%, retinol propionate 0.4%, phenoxyethanol 0.6%, ethylhexyl glycerol 0.06%, the balance water.

The composite liquid crystal emulsifier also comprises polar oil, and specifically comprises the following components:

TWEEN-200.2%, TWEEN-600.8%, cetostearyl alcohol 10%, retinol propionate 0.3%, phenoxyethanol 0.6%, ethylhexyl glycerol 0.06%, polar oil 2%, the balance water.

Wherein the polar oil is one or more of wheat germ oil, jojoba oil, pentaerythritol tetra (ethyl caproic acid) ester, caprylic capric Glyceride (GTCC), isopropyl myristate (IPM) and squalane.

The invention also provides a preparation method of the composite liquid crystal emulsifier, which comprises the following steps:

mixing cetostearyl alcohol, retinol propionate, polar oil, tween 20 and tween 60 to obtain an oil phase;

mixing phenoxyethanol, ethylhexyl glycerol and water to obtain a water phase;

mixing the oil phase and the water phase, homogenizing and emulsifying for 2-3min;

and (3) carrying out water bath on the homogenized and emulsified system for 1-2min, slowly stirring, and defoaming to obtain the composite liquid crystal emulsifier.

In some embodiments, the mixing is by: the oil phase is added to the aqueous phase.

In some embodiments, the mixing is preceded by the step of heating the oil phase and the water phase to 75-90 ℃ respectively, and stirring well.

In some embodiments, the homogenization temperature is 75-80℃and the homogenization speed is 10000-13000rpm.

The invention also provides application of the composite liquid crystal emulsifier in preparing cosmetics.

The composite liquid crystal emulsifier provided by the invention comprises TWEEN-20, TWEEN-60, cetostearyl alcohol, retinol propionate, phenoxyethanol, ethylhexyl glycerol and water. Experiments show that a super-depth-of-field microscope observes that a system has a dense and uniform concentric microcapsule structure, and the retinol propionate is successfully coated by cetylstearyl alcohol, and the embedding rate reaches 90.87%; the polarizing microscope verifies that the capsule wall forms a liquid crystal structure; the degradation of the inner core material within 32 days is 16.02%, which shows that the system has high embedding rate of the retinol propionate and good stability and slow release performance.

2% polar oil is added on the basis of the formula. The results show that the oil polarity has no significant effect on the microcapsule embedding rate; sample core material prepared from pentaerythritol tetra (ethylhexanoate) with medium polarity within 32 days has the lowest degradation rate of 17.38%; a uniform microcapsule structure is observed under a super-depth-of-field microscope; the polarizing microscope verifies that the wall forms a liquid crystal structure.

Drawings

FIG. 1 is a graph of the acceleration comparisons of the emulsifier samples of comparative examples 1-2, and FIG. 1 (a) is a graph of the samples of comparative example 1 and comparative example 2, in order from left to right, with the test time of FIG. 1 (a) being 7 days, the test time of FIG. 1 (b) being 14 days, the test time of FIG. 1 (c) being 21 days, and the test time of FIG. 1 (d) being 28 days; the left graph shows the results of comparative example 2, and the right graph shows the results of comparative example 1;

FIG. 2 is a comparative example 1-2 emulsifier sample super depth of field microscope image, left image is the result of comparative example 2, right image is the result of comparative example 1;

FIG. 3 is a polarizing microscope image of the emulsifier samples of comparative examples 1-2, the left image is the result of comparative example 2, and the right image is the result of comparative example 1;

FIG. 4 is a graph showing the results of the accelerated experiments of the compound emulsifier samples of comparative examples 3 to 9, and graphs (a) to (d) show the results of the test for 7 days, 14 days, 21 days and 28 days in sequence, wherein the samples of comparative example 3, comparative example 7, comparative example 8, comparative example 9, comparative example 4, comparative example 5 and comparative example 6 are shown in sequence from left to right;

FIG. 5 is a super depth of field microscopic image of the compounded emulsifier samples of comparative examples 3-9, and (a) - (g) are samples of comparative example 3, comparative example 7, comparative example 8, comparative example 9, comparative example 4, comparative example 5, comparative example 6 in order;

FIG. 6 is a graph showing the acceleration comparison of samples of examples 4, 7, 10 and 13, and graphs (a) to (d) show the results of the test for 7 days, 14 days, 21 days and 28 days in this order, wherein samples of example 4, example 7, example 10 and example 13 are shown in this order from left to right;

FIG. 7 is a super depth of field microscope image of the samples of examples 4, 7, 10, and 13, wherein (a) is the sample of example 4, (b) is the sample of example 7, (c) is the sample of example 10, and (d) is the sample of example 13;

FIG. 8 is an acceleration comparison chart of the samples of examples 17 to 22, which are the samples of examples 17 to 22 in order from left to right;

FIG. 9 shows the characterization of the wall-liquid crystal structure by a super depth-of-field microscope for the samples of examples 17-22, wherein (a) - (f) are the samples of examples 17-22 in order;

FIG. 10 shows the characterization of the wall-liquid crystal structure by a polarizing microscope for samples of examples 17 to 23, wherein (a) to (f) are samples of examples 17 to 22 in this order.

Detailed Description

The invention provides a composite liquid crystal emulsifier, a preparation method and application thereof. Those skilled in the art can, with the benefit of this disclosure, suitably modify the process parameters to achieve this. It is specifically noted that all similar substitutions and modifications will be apparent to those skilled in the art, and are intended to be included in the present invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those skilled in the relevant art that variations and modifications can be made in the methods and applications herein, or in the appropriate variations and combinations, without departing from the spirit and scope of the invention.

The experimental method used in the invention comprises the following steps:

1. and (3) embedding rate measurement:

the embedding rate is an important index for evaluating the quality of the microcapsule system, and the determination principle is as follows: and measuring the content of the free core material in the system by an ultraviolet spectrophotometer, and indirectly calculating to obtain the content of the core material embedded in the microcapsule.

The embedding rate calculation process is as follows:

retinol propionate is dissolved in methanol and cetostearyl alcohol as a wall material is insoluble in methanol at normal temperature, so that absolute methanol is selected as a solvent in the embedding rate measurement process, and the free retinol propionate in a system is dissolved.

Embedding rate measurement process:

(1) The prepared samples were weighed 1g each using a precision balance and placed in centrifuge tubes, respectively.

(2) 5ml of absolute methanol was added and centrifuged at 10000r/min for 8min using a high-speed centrifuge.

Taking the supernatant after centrifugation, filtering the supernatant by a microporous filter membrane with the size of 0.22 mu m, and diluting the filtrate by a certain multiple. The absorbance was measured at 325nm using an ultraviolet spectrophotometer, and the content of free retinol propionate in the system was calculated by standard curve method. And calculating the embedding rate according to the formula.

2. Determination of degradation Rate

The degradation rate is an important index for examining the protection degree and the slow release effect of the liquid crystal microcapsule system on the retinol propionate, and the slower the degradation rate of the retinol propionate in the system in a certain time, the better the protection and the slow release performance of the system on new materials are shown.

The prepared sample was placed in a constant temperature incubator at a temperature of 40 ℃. Observing the yellowing degree of the sample at 7 days, 14 days, 21 days and 28 days respectively, and photographing for storage; the degradation rate of retinol propionate was measured by sampling at 8, 16, 24, and 32 days, respectively.

The degradation rate is calculated as follows:

absolute ethyl alcohol is selected for use in the research, a sample is dissolved under ultrasonic conditions, then an ultraviolet spectrophotometer is used for measuring absorbance, and the content of retinol propionate in the system is calculated through a standard curve method.

The degradation rate measurement process comprises the following steps:

(1) The prepared samples were weighed 1g each using a precision balance and placed in 20ml volumetric flasks, respectively.

(2) Absolute ethyl alcohol is added to fix the volume to the scale mark, and an ultrasonic cleaner is used for completely dissolving the sample under the condition of 80 Hz.

(3) And taking a treated sample, and diluting the treated sample by a certain multiple with absolute ethyl alcohol. Absorbance was measured using an ultraviolet spectrometer.

The retinol propionate degradation rate was then calculated according to the above formula.

3. Characterization of liquid Crystal microcapsule morphology

The sample was observed for microcapsule morphology using a super depth of field microscope. The prepared specimen is placed on an objective table, and the instrument is adjusted to enable a clear object image to be displayed in the visual field. The morphology of the sample microcapsules in different areas can be observed by adjusting the position of the sample. And (3) photographing and preserving the microcapsule form of the sample through a digital camera connected with the micro-mirror when observing the area with regular microcapsule structure and uniform distribution.

The liquid crystal structure of the capsule wall of the sample is characterized by using a polarizing microscope, the prepared sample is placed on an objective table, and the instrument is adjusted to enable a clear object image to be displayed in the visual field. The morphology of the sample microcapsules in different areas can be observed by adjusting the position of the sample. And (3) photographing and preserving the liquid crystal structure of the sample by a digital camera device connected with the micro-mirrors when observing the area with regular microcapsule structure and uniform distribution.

4. Acceleration test

Acceleration tests are a test method based on loading the system. Specific measures include heating, centrifugation, etc. Temperature-based acceleration tests are performed using either constant temperature or freeze-high temperature cycles. The principle of the high temperature acceleration test is based on the Arrhenius equation describing the relationship between the chemical reaction rate constant and the temperature, and the majority of the chemical reaction rate doubles every 10 ℃ rise in temperature. Stability data of the sample can be obtained in a short time by the acceleration test.

The main reason for emulsion stability is that the interfacial film has sufficient mechanical strength. Thus, any factor that may weaken the interfacial film may result in demulsification. The emulsion is subjected to an acceleration test under a high-temperature condition, on one hand, the solubility of the emulsifier is increased by the increase of the temperature, the adsorption capacity of the emulsifier on an interface is reduced, and the protective film is weakened; on the other hand, increasing the temperature reduces the viscosity of the external phase of the droplets and increases the risk of droplet collisions and demulsification.

According to the invention, the prepared sample is placed in a constant temperature incubator, the melting point of cetylstearyl alcohol based on a wall material is 48-50 ℃, the temperature of the incubator is set to 40 ℃ on the premise of ensuring the integrity of the capsule wall structure, the appearance change of the sample is photographed and recorded every 7 days, and the degradation rate of retinol propionate in the sample is measured every 8 days.

The test materials adopted by the invention are all common commercial products and can be purchased in the market.

The invention is further illustrated by the following examples:

EXAMPLES 1-16 preparation of the composite liquid Crystal emulsifier of the invention

Table 1 formulation composition (w/w%)

The preparation method comprises the following steps: (1) The oil phase (cetostearyl alcohol, retinol propionate, polar oil, tween 20, tween 60) and the water phase (phenoxyethanol, ethylhexyl glycerol and water) were weighed using a precision balance, placed in different beakers, heated to 75-90 ℃ respectively, until cetostearyl alcohol melted, and the two phases were stirred evenly using a glass rod respectively.

(2) Adding the oil phase into the water phase at one time at heating temperature, homogenizing for 2-3min under 10000r/min with an emulsifying homogenizer.

Placing the homogenized sample in hot water for 1-2min at intervals of a beaker, slowly stirring to float foam in the system, and performing defoaming treatment.

The defoamed sample is placed in cold water in a beaker at intervals, and is slowly stirred to be quickly cooled to room temperature. Finally, dividing the prepared sample into two parts, wherein one part is placed in a constant temperature incubator at 40 ℃ to follow the appearance change and the degradation rate of retinol propionate; the other part is used for determination and morphological characterization of the embedding rate.

Preparation of composite liquid Crystal emulsifiers of comparative examples 1 to 9

The formulation is shown in Table 2.

Table 2 comparative example liquid Crystal microcapsule formulation composition/%Table 1 formulation composition (w/w%)

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The preparation method is the same as in examples 1 to 16.

Test example 1

The embedding rate and degradation rate of retinol propionate in the composite liquid crystal emulsion systems of examples 1 to 26 and comparative examples 1 to 9 according to the present invention were measured according to the method described in the present invention, and the results are shown in tables 3 to 4.

TABLE 3 embedding rate/%of liquid crystal microcapsules formed by the inventive compound emulsifier

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TABLE 4 degradation rate measurement results

As can be seen from Table 4, the degradation rate data shows that the degradation rate of the samples with the total concentration of emulsifier 1 (comparative example 3) and the total concentration of emulsifier 3 (comparative example 5) being 2% is lower, and the degradation rate of the samples prepared with the high concentration of emulsifier is higher. Probably because when the content of the emulsifier is higher, a part of the emulsifier can emulsify two adjacent liquid drops simultaneously, so that the risk of the collision of the liquid drops is increased, the original stable system is unstable, and the degradation rate of the core material is increased.

Within 32 days, the degradation rate of the samples is between 16% and 60%, and the samples have larger difference. Wherein the sample of the example 4 has 16.02% of degradation in 32 days, and good protection and slow release capability of the retinol propionate.

Comparative examples 1-2 acceleration experiments as shown in fig. 1, samples of comparative example 1 and comparative example 2 were shown in fig. 1 (a) from left to right, and the test time of fig. 1 (a) was 7 days, the test time of fig. 1 (b) was 14 days, the test time of fig. 1 (c) was 21 days, and the test time of fig. 1 (d) was 28 days.

As can be seen from FIG. 1, the products of comparative example 1 (group 1) and comparative example 2 (group 2) both had a yellowing in appearance within 28 days, and the degree of yellowing of group 2 was higher than that of the group 1 sample, indicating a higher degree of degradation of retinol propionate in the group 1 product (comparative example 1).

The super depth of field microscope characterizes the microcapsule structure: the shape, size and distribution of the liquid crystal microcapsules were observed by a super depth of field microscope to investigate whether retinol propionate was successfully coated. The system microcapsule morphology is shown in FIG. 2, and as can be seen from FIG. 2, the system prepared by using TWEEN-20 of group 1 of Table 1 as emulsifier is in a dense particle morphology, and the microcapsule structure cannot be observed; the samples prepared in group 2TWEEN-60 of Table 1 can observe a large number of well-structured microcapsule structures. From the above results, it is clear that the kind of emulsifier (TWEEN-20, TWEEN-60) directly affects the formation of microcapsule structure in the same system. TWEEN-60 facilitates the formation of microcapsule structures that cannot be made with TWEEN-20 alone to produce an emulsion system containing microcapsule structures.

Characterization of the wall liquid crystal structure by a polarized microscope: the liquid crystal microcapsule wall liquid crystal structures prepared in Table 1 are shown in FIG. 3, FIG. 3 (a) TWEEN-20 and FIG. 3 (b) TWEEN-60. As shown in FIG. 3, the cell wall of the sample prepared from TWEEN-20 has no liquid crystal structure, and the sample prepared from TWEEN-60 can observe a more obvious liquid crystal structure.

Comparative examples 3 to 9 correspond to samples 1 to 7, respectively, and the acceleration test pair is shown in fig. 4: in fig. 4,

samples

1, 5, 6, 7, 2, 3, 4 are shown in fig. 4 (a) from left to right; fig. 4 (a): 7 days fig. 4 (b): day 14 fig. 4 (c) 21 days fig. 4 (d) 28 days.

As can be seen from FIG. 4, samples 1 to 7 all had yellowing in appearance within 28 days, wherein samples 1, 2 and 3 at low concentrations had a lower degree of yellowing, and samples 4, 5, 6 and 7 at high concentrations had a higher degree of yellowing, and their retinol propionate degradation rates were higher than those prepared with the low concentrations. Indicating that for this system, lower concentrations of emulsifier are beneficial for improved system performance.

The super depth of field microscope characterizes the microcapsule structure: fig. 5 is a microscopic view of the compound emulsifier sample over depth of field, fig. 5 (a) 1% emulsifier, fig. 5 (b), 1.5% emulsifier, fig. 5 (c) 2% emulsifier, fig. 5 (d) 2.5% emulsifier, fig. 5 (e) 3% emulsifier, fig. 5 (f) 5% emulsifier, fig. 5 (g) 7% emulsifier.

As is clear from FIG. 5, the microcapsule structure was observed at the amounts of 1%, 1.5%, 2% and 2.5% and hardly observed at the amounts of 5% and 7%.

Comparison of acceleration experiments of examples 4, 7, 10, 13: FIG. 6 is a graph of the acceleration comparison of samples of retinol propionate according to examples 4, 7, 10, and 13; samples 4, 7, 10, 13 are sequentially from left to right; fig. 6 (a): 7 days, fig. 6 (b): 14 days, 21 days in FIG. 6 (c), and 28 days in FIG. 6 (d). It can be seen that sample No. 4 had the lowest yellowing at each concentration of propionate content, indicating a relatively low degree of degradation of the core material.

The super depth of field microscope characterizes the microcapsule morphology: FIG. 7 is a sample super depth of field microscope image; fig. 7 (a) - (d) are the super depth of field microscopes of examples 4, 7, 10, and 13, respectively, wherein (a) is the sample of example 4, (b) is the sample of example 7, (c) is the sample of example 10, and (d) is the sample of example 13.

Examples 17 to 22

The influence of the oil polarity on the formation of the liquid crystal microcapsule structure is explored by using six liquid oils with different polarities, and the liquid crystal microcapsules of examples 17-22 are prepared by using wheat germ oil, jojoba oil, pentaerythritol tetra (ethyl caproate), caprylic acid Glyceride (GTCC), isopropyl myristate (IPM) and squalane with the polarities from strong to weak.

The formulation is shown in Table 5.

TABLE 5 formulation composition/%

Test example 2 influence of liquid oil polarity on liquid Crystal microcapsule System

The formulation systems of examples 17 to 22 were tested for entrapment and degradation of retinol propionate according to the methods described herein, and the results are shown in tables 6 to 7.

TABLE 6 embedding Rate of liquid Crystal microcapsules/%

Sample of	Embedding rate/%
		Example 17	76.42
Example 18	80.86
		Example 19	87.09
Example 20	72.87
		Example 21	81.70
Example 22	85.62

As can be seen from Table 5, the embedding rate of the samples prepared by adding liquid oils of different polarities was in the range of 72% -88%, wherein the embedding rate of the sample of example 26 (sample No. 3) to which GTCC was added was 87.09% at the highest.

TABLE 7 degradation rate/%of retinol propionate for different polarity oil samples

As is clear from Table 6, the sample to which pentaerythritol tetra (ethylhexanoate) was added was degraded 17.38% in 32 days, and the sample to which jojoba oil was added was degraded 18.22% in 32 days, indicating that both of these systems had good protection and slow release ability for the retinol propionate.

The comparison result of the acceleration experiment is shown in fig. 8, and the samples prepared from IPM, jojoba oil, GTCC, pentaerythritol tetra (ethyl hexanoate), wheat germ oil and squalane are shown in fig. 8 (a) from left to right. Fig. 8 (a) - (d) are samples at different test times. Fig. 8 (a): 7 days, fig. 8 (b): 14 days, 21 days in FIG. 8 (c), and 28 days in FIG. 8 (d).

As can be seen from FIG. 8, samples with different polarity liquid oils had different degrees of yellowing within 28 days, with Nos. 1 and 4 (examples 24 and 27) having the lowest degree of yellowing, indicating a lower degree of degradation of retinol propionate.

Characterization of the wall liquid crystal structure by a polarized microscope: preferably, samples No. 1 (IPM) and No. 4 (pentaerythritol tetra (ethylhexanoate)) with the lowest degradation rate and higher embedding rate of retinol propionate are used for observing the liquid crystal structure of the capsule wall by using a polarization microscope.

Fig. 9 is a super depth of field microscope for different polarity oil samples. FIG. 9 (a) IPM, (b) pentaerythritol tetrakis (ethylhexanoate). The polarized light pictures show that the liquid crystal forming conditions of the capsule wall of the sample 1 and the liquid crystal of the capsule wall of the sample 4 are similar, and a uniform liquid crystal structure can be observed to appear on the capsule wall, and the liquid crystal forming condition of the sample 4 is better than that of the sample 1, but the liquid crystal amount is less than that of the sample without liquid oil.

From the above results, the number of the microcapsules containing the liquid crystal structure prepared in the embodiment 4 of the invention is dense and uniform, the obvious liquid crystal structure can be observed on the capsule wall, the retinol propionate is degraded by 16.02% within 32 days, and the protection and slow release effects on the core material are good.

The invention further explores the influence of oil polarity on the formation rule of the liquid crystal microcapsules, and experimental results show that the oil polarity has no obvious difference on the formation of the microcapsules, but has a certain difference on the protection capability of the core material, wherein a sample of pentaerythritol tetra (ethyl hexanoate) with medium polarity is added, retinol propionate is degraded by 17.38% within 32 days, and the protection capability of the core material is stronger. The super-depth-of-field microscope observes that the system has dense and uniform concentric microcapsule structures, which shows that retinol propionate is successfully coated by cetylstearyl alcohol, and the embedding rate reaches 90.87%; the polarizing microscope verifies that the capsule wall forms a liquid crystal structure; the degradation of the core material is 16.02% within 32 days, and the system has good protection and slow release performance on the core material.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. The composite liquid crystal emulsifier is characterized by comprising the following components in percentage by mass: TWEEN-20.2-0.4%, TWEEN-60.6-0.8%, cetostearyl alcohol 10-12%, retinol propionate 0.4%, phenoxyethanol 0.6%, ethylhexyl glycerol 0.06%, the balance water.

2. The composite liquid crystal emulsifier according to claim 1, which is characterized by comprising the following components in percentage by mass:

TWEEN-20.2%, TWEEN-60.8%, cetostearyl alcohol 12%, retinol propionate 0.4%, phenoxyethanol 0.6%, ethylhexyl glycerol 0.06%, the balance water.

3. The composite liquid crystal emulsifier is characterized by comprising the following components in percentage by mass: TWEEN-20.2%, TWEEN-60.8%, cetostearyl alcohol 10%, retinol propionate 0.3%, phenoxyethanol 0.6%, ethylhexyl glycerol 0.06%, polar oil 2%, the balance water.

4. The compound liquid crystal emulsifier according to claim 3, wherein the polar oil is one or more of wheat germ oil, jojoba oil, pentaerythritol tetra (ethylhexanoate), caprylic capric Glyceride (GTCC), isopropyl myristate (IPM), and squalane.

5. The method for preparing a composite liquid crystal emulsifier according to claim 3 or 4, comprising:

mixing cetostearyl alcohol, retinol propionate, polar oil, TWEEN-20, TWEEN-60 to obtain oil phase;

mixing phenoxyethanol, ethylhexyl glycerol and water to obtain a water phase;

6. The method according to claim 5, wherein the mixing is performed by: the oil phase is added to the aqueous phase.

7. The method according to claim 5, further comprising the step of heating the oil phase and the water phase to 75-90 ℃ respectively and stirring them uniformly before the mixing.

8. The preparation method according to claim 5, wherein the homogenizing temperature is 75-80 ℃, and the homogenizing speed is 10000-13000 r/min.

9. Use of the composite liquid crystal emulsifier according to any one of claims 1 to 4 or the composite liquid crystal emulsifier prepared by the preparation method according to any one of claims 5 to 8 in the preparation of cosmetics.