Preparation method of safflower seed oil cosmetic emulsion based on micro-nano fluidics

Abstract

This invention discloses a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, relating to the field of cosmetic technology. The invention includes the following steps: S1, preparing the oil phase: 0.2wt%-1wt% of safflower seed oil, 1wt%-10wt% of polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier are mixed evenly to obtain an oil phase mixed solution; S2, preparing the aqueous phase: water-soluble excipients 1,3-butanediol and glycerol are dissolved in distilled water and stirred until clear to obtain an aqueous phase mixed solution; S3, micro-nanofluidic emulsification: precise emulsification is performed using a three-dimensional micro-nanofluidic chip system; the oil phase and aqueous phase are sheared and mixed within the micro-nanofluidic channel; the oil-water two-phase flow rate ratio is 1:10~1:30, and the operating temperature is 25℃-65℃; S4, collection and output: the cosmetic emulsion flowing from the chip outlet is collected to obtain the safflower seed oil cosmetic emulsion. This invention uses micro-nano fluidic equipment to prepare cosmetic emulsions with an average diameter in the range of 60nm-300nm, which have the advantages of high stability and strong skin absorption.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, specifically providing a method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization. Background Technology

[0002] Nanoemulsions, as a highly efficient active ingredient delivery system, can significantly improve the dispersibility, stability, and transdermal absorption efficiency of hydrophobic oils. Safflower seed oil is a natural plant extract rich in linoleic acid, vitamin E, phytosterols, and other active ingredients. In cosmetics, it has excellent multiple skincare benefits, including anti-oxidation, moisturizing and repairing, soothing and anti-inflammatory effects, and promotion of skin barrier regeneration.

[0003] However, when safflower seed oil is encapsulated in nanoemulsions for use in cosmetics, it is found that safflower seed oil is a typical hydrophobic active ingredient. When directly added to water-based cosmetic systems, it has poor solubility, the average diameter of the resulting cosmetic emulsion is large, and the skin permeability is poor. As a result, safflower seed oil is difficult to absorb and utilize, leading to poor practical application effects. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization.

[0005] The technical solution of the present invention is as follows:

[0006] A method for preparing a safflower seed oil cosmetic emulsion based on micro / nanofluidics includes the following steps:

[0007] S1. Prepare the oil phase by mixing 0.2wt%-1wt% of safflower seed oil, 1wt%-10wt% of polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier in a total mass ratio to obtain an oil phase mixed solution.

[0008] S2. Prepare an aqueous phase by dissolving 5 wt%-15 wt% of water-soluble excipients 1,3-butanediol and 1 wt%-10 wt% of glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0009] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:5~1:30, and the operating temperature is 25℃-65℃.

[0010] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain safflower seed oil cosmetic emulsion.

[0011] In this method, safflower seed oil is prepared in the oil phase and emulsified by a micro-nano fluidic chip system to stably obtain a nanoscale cosmetic emulsion. The average particle size of the prepared cosmetic emulsion is within 60nm-300nm, and the particle size distribution is uniform, which can avoid mutual absorption and binding of cosmetic emulsions, resulting in high stability. Furthermore, cosmetic emulsions with this average particle size can ensure their skin permeability.

[0012] Preferably, the total flow rate of the oil-water two phases within the micro / nano fluidic channel is 200 µL / min to 20000 µL / min. In this scheme, nanoscale cosmetic emulsions can be prepared within this total flow rate range.

[0013] Laboratory-grade cosmetic emulsions have stringent requirements for average particle size and PDI (particulate density). The average particle size needs to be controlled within 100 nm. To ensure efficient production, when using safflower seed oil at a mass ratio of 0.5 wt% in laboratory preparation, the total flow rate of the oil-water two-phase mixture is 1040-1380 µL / min. At this flow rate, the average particle size of the cosmetic emulsion can be controlled to around 60 nm, and the PDI can be controlled to approximately 0.2, thus maximizing laboratory production efficiency.

[0014] To address the issue of low yield in cosmetic emulsion production, a total flow rate of 50-500 mL / min is adopted for the oil-water two-phase system when the safflower seed oil content is 0.5 wt%. At this flow rate, the yield of the cosmetic emulsion can be increased to 200 mL / min, meeting the requirements of mass production. Furthermore, under this condition, the average particle size of the cosmetic emulsion is 192 nm, and the PDI is 0.219, exhibiting advantages such as small average particle size and uniform particle size distribution.

[0015] To address the issue of the inability of cosmetic emulsions to achieve long-term stable storage, a mixed emulsifier ratio of polyglycerol-10 oleate and polyglycerol-2 oleic acid is used, ranging from 2:1 to 10:1. In this formulation, relatively stable cosmetic emulsions can be prepared within this ratio range.

[0016] To further address the issue of large average particle size in the obtained cosmetic emulsions, the downstream channel at the junction of the oil and aqueous phases in the micro / nanofluidic chip includes sections with different cross-sectional areas. These varying cross-sectional areas promote the mixing of the liquids, thereby reducing the average particle size of the cosmetic emulsion. In this solution, by altering the channel cross-sectional area, the mixed liquids interact further, promoting the formation of smaller droplets and improving the conversion rate between the oil and aqueous phases.

[0017] To address the challenge of controlling average particle size and PDI due to increased overall flow rate during mass production, the proposed three-dimensional micro / nano fluid control chip system incorporates a three-dimensional channel within which the oil and aqueous phases converge and assemble to form a cosmetic emulsion. This solution increases the complexity of the flow paths for the aqueous, oil, and cosmetic emulsion phases through the three-dimensional channel, thereby enhancing the shear forces during flow. This allows for controlled average particle size and PDI control during mass production while maintaining stable average particle size and PDI in the cosmetic emulsion, ultimately increasing yield.

[0018] Preferably, the three-dimensional channel includes several X-shaped, H-shaped, or a combination of both hybrid units. Multiple liquid confluence points are formed through the combination of X-shaped and H-shaped hybrid units, increasing the number of liquid confluence shearing operations within the micro / nanofluidic chip.

[0019] This invention provides a safflower seed oil cosmetic emulsion based on micro-nano fluidization, wherein the safflower seed oil has a mass ratio of 0.2wt%-1wt%, the polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier has a mass ratio of 2wt%, the 1,3-butanediol has a mass ratio of 15wt%, the glycerol has a mass ratio of 2wt%, and the remainder is distilled water.

[0020] Preferably, the safflower seed oil accounts for 0.5 wt% of the total mass. This proportion ensures that the cosmetic emulsion contains sufficient safflower seed oil while maintaining a stable and controllable average particle size.

[0021] The beneficial effects of this invention are:

[0022] This invention uses micro-nano fluidic equipment to prepare cosmetic emulsions with an average diameter in the range of 60nm-300nm, which have the advantages of high stability and strong skin absorption. Attached Figure Description

[0023] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 The bar chart shows the average particle size and PDI of Examples 1 to 4;

[0025] Figure 2 The bar chart shows the average particle size of the cosmetic emulsion from Example 4 after standing at 48°C for 1 day and 30 days.

[0026] Figure 3The bar chart shows the PDI of the cosmetic emulsion in Example 4 after standing at 48°C for 1 day and 30 days.

[0027] Figure 4 The particle size distribution of the cosmetic emulsion in Example 4 after standing at 48°C for 1 day and 30 days is shown.

[0028] Figure 5 The bar chart shows the average particle size of the cosmetic emulsion from Comparative Example 1 after standing at 48°C for 1 day and 30 days.

[0029] Figure 6 The bar chart shows the PDI of the cosmetic emulsion in Comparative Example 1 after standing at 48°C for 1 day and 30 days.

[0030] Figure 7 The particle size distribution of the cosmetic emulsion in Comparative Example 1 after standing at 48°C for 1 day and 30 days is shown.

[0031] Figure 8 The bar chart shows the average particle size and PDI of Examples 5 to 8. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described in conjunction with the accompanying drawings and through specific embodiments of the present invention.

[0033] Example 1:

[0034] This embodiment provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0035] S1. Prepare the oil phase by mixing 0.2wt% safflower seed oil with 2wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0036] S2. Prepare the aqueous phase by dissolving 15wt% of water-soluble excipients, 1,3-butanediol, and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0037] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1380µL / min, and the operating temperature is 60℃.

[0038] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 0.2wt% safflower seed oil cosmetic emulsion.

[0039] The cosmetic emulsion collected in step S4 has an average particle size of 68 nm and a PDI value of 0.29.

[0040] In the cosmetic emulsion, safflower seed oil accounts for 0.2 wt% of the total mass, polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier accounts for 2 wt% of the total mass, 1,3-butanediol accounts for 15 wt% of the total mass, glycerin accounts for 2 wt% of the total mass, and the remainder is distilled water.

[0041] The three-dimensional micro / nanofluidic chip system internally comprises three-dimensional channels. By coordinating these channels, total flow rate control, and the mass ratio of safflower seed oil, the average particle size of the cosmetic emulsion is controlled at 68 nm, while the PDI is maintained at 0.29. The three-dimensional channels include several X-type, H-type, or hybrid units combining both. The X-type or H-type cross-structure increases the shearing frequency and duration between the oil and water phases, enhancing their combination effect and resulting in a cosmetic emulsion with a smaller average particle size. Furthermore, the three-dimensional micro / nanofluidic chip is made of quartz / glass, offering advantages such as high pressure resistance, organic solvent resistance, and optical transparency for easy observation.

[0042] As an alternative approach, in a three-dimensional channel, the downstream section where the oil and water phases meet has sections with different cross-sectional areas. As the cross-sectional area of ​​the channel changes, the mixed liquids interact with each other due to the change in channel size, further enhancing the mixing effect. The channel cross-sectional area can be further amplified by a periodic change of shrinking-expanding-shrinking, thereby further reducing the average particle size of the obtained cosmetic emulsion.

[0043] Example 2:

[0044] This second embodiment provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization, including the following steps:

[0045] S1. Prepare the oil phase by mixing 0.3wt% safflower seed oil with 2wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0046] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0047] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1380µL / min, and the operating temperature is 60℃.

[0048] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 0.3wt% safflower seed oil cosmetic emulsion.

[0049] The cosmetic emulsion collected in step S4 has an average particle size of 60 nm and a PDI value of 0.19.

[0050] Example 3:

[0051] This embodiment three provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0052] S1. Prepare the oil phase by mixing 0.4 wt% safflower seed oil with 2 wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0053] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0054] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1380µL / min, and the operating temperature is 60℃.

[0055] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 0.4wt% safflower seed oil cosmetic emulsion.

[0056] The cosmetic emulsion collected in step S4 has an average particle size of 61 nm and a PDI value of 0.2.

[0057] Example 4:

[0058] This embodiment four provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0059] S1. Prepare the oil phase by mixing 0.5wt% safflower seed oil with 2wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0060] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0061] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1380µL / min, and the operating temperature is 60℃.

[0062] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 0.5wt% safflower seed oil cosmetic emulsion.

[0063] The cosmetic emulsion collected in step S4 has an average particle size of 69 nm and a PDI value of 0.19.

[0064] like Figure 1 As shown, comparing Examples 1, 2, 3, and 4, when the mass fraction of safflower seed oil was increased from 0.2 wt% to 0.5 wt%, the average particle size of the resulting cosmetic emulsion remained approximately 60 nm, and the PDI value remained approximately 0.2. Even with fluctuations in the values, the changes were not significant. When the mass fraction was below 0.5 wt%, changes in the mass fraction had little impact on the average particle size and PDI of the cosmetic emulsion.

[0065] like Figure 2 and Figure 3 As shown, samples of the cosmetic emulsion prepared in Example 4 were taken and left to stand at 48°C for 30 days. The changes were observed, revealing that the average particle size of the emulsion increased slowly, by only about 0.7 nm, and the PDI value increased from 0.19 to 0.21, an increase of only 0.02. This indicates that the cosmetic emulsion of Example 4 has high stability and can be stored for a long time. Figure 4 As can be seen from the branch tubes, the particle size distribution of the cosmetic emulsion remains generally stable.

[0066] Example 5:

[0067] This fifth embodiment provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0068] S1. Prepare the oil phase by mixing 0.5wt% safflower seed oil with 2wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0069] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0070] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1040µL / min, and the operating temperature is 60℃.

[0071] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 0.5wt% safflower seed oil cosmetic emulsion.

[0072] The cosmetic emulsion collected in step S4 has an average particle size of 69.2 nm and a PDI value of 0.19.

[0073] Comparing Examples 4 and 5, the difference lies in the total flow rate. The total flow rate in Example 4 was 1380 µL / min, while in Example 5 it was 1040 µL / min. This difference in total flow rate results in an average particle size of 69 nm and a PDI of 0.19 for the cosmetic emulsion obtained in Example 4, compared to 69.2 nm and a PDI of 0.19 for the cosmetic emulsion obtained in Example 5. The decrease in total flow rate leads to an increase in the average particle size of the cosmetic emulsion, demonstrating the effect of adjusting the average particle size by controlling the total flow rate.

[0074] Example 6:

[0075] This embodiment six provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0076] S1. Prepare the oil phase by mixing 0.7wt% safflower seed oil with 2wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0077] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0078] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1040µL / min, and the operating temperature is 60℃.

[0079] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 0.7wt% safflower seed oil cosmetic emulsion.

[0080] The cosmetic emulsion collected in step S4 has an average particle size of 126.02 nm and a PDI value of 0.229.

[0081] Example 7:

[0082] This embodiment seven provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0083] S1. Prepare the oil phase by mixing 0.9 wt% safflower seed oil with 2 wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0084] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0085] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1040µL / min, and the operating temperature is 60℃.

[0086] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 0.9wt% safflower seed oil cosmetic emulsion.

[0087] The cosmetic emulsion collected in step S4 has an average particle size of 229.3 nm and a PDI value of 0.29.

[0088] Example 8:

[0089] This embodiment eight provides a method for preparing a safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0090] S1. Prepare the oil phase by mixing 1.0 wt% safflower seed oil with 2 wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0091] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0092] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 1040µL / min, and the operating temperature is 60℃.

[0093] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 1.0wt% safflower seed oil cosmetic emulsion.

[0094] The cosmetic emulsion collected in step S4 has an average particle size of 272.82 nm and a PDI value of 0.385.

[0095] like Figure 8 As shown in the comparative examples 5, 6, 7, and 8, as the mass fraction of safflower seed oil gradually increased from 0.5 wt% to 1.0 wt%, the particle size of the obtained cosmetic emulsion gradually increased from 69.2 nm to 272.82 nm, and the PDI also increased from 0.19 to 0.385. Both the average particle size and the PDI value of the cosmetic emulsion increased significantly. This indicates that when the mass fraction of safflower seed oil exceeds 0.5 wt%, the mass fraction of safflower seed oil has a significant impact on the average particle size of the cosmetic emulsion. Therefore, in the laboratory, the preferred approach is to control the mass fraction of safflower seed oil at 0.5 wt% to ensure that a cosmetic emulsion with an average diameter of approximately 60 nm can be obtained.

[0096] After determining that 0.5 wt% was the optimal mass fraction in the laboratory, based on the technical solution of Example 4, the total flow rate was adjusted. It was found that cosmetic emulsions could be produced within the range of 200 µL / min to 20000 µL / min. However, when the total flow rate was between 200 µL / min and 500 µL / min, the average particle size of the cosmetic emulsion could be below 60 nm, but the yield was only at the µL / min level, requiring several hours to prepare 100 mL of sample, which could not meet the needs of cosmetic research and development or production. The experiment showed that when the total flow rate was 1380 µL / min and the mass fraction of safflower seed oil was controlled below 0.5 wt%, the average particle size of the cosmetic emulsion could still be controlled between 60 nm and 70 nm. The increase in the average particle size was small, but the production speed increased by nearly three times. Therefore, a total flow rate of 1380 µL / min is the optimal total flow rate when the mass fraction of safflower seed oil is controlled below 0.5 wt%, and is suitable for laboratory production. When the mass fraction of safflower seed oil is controlled above 0.5wt%, the best effect is achieved by controlling the total flow rate at 1040µL / min.

[0097] Based on the scheme of Example 4 above, the operating temperature was further varied. By comparing the emulsification effect and active ingredient retention rate at 25℃, 40℃, 60℃, and 70℃, 60℃ was determined to be the optimal emulsification temperature. It was found that in all examples, when the operating temperature was below 40℃, the safflower seed oil had high viscosity (>50 mPa·s), resulting in high flow resistance within the microchannels. The shear force was insufficient to effectively break down the oil phase, forming large-particle-size emulsions (>150 nm), and easily clogging the channels. While at temperatures above 70℃, although the viscosity decreased and emulsification was easier, linoleic acid (70–85%) and vitamin E in the safflower seed oil underwent thermal oxidative degradation, resulting in an active ingredient loss rate >20%, thus losing its cosmetic efficacy value. Therefore, after testing, the preferred operating temperature was 50℃-65℃, preferably 60℃.

[0098] Based on the scheme of Example 4 above, the flow rate ratio of the oil and water phases was adjusted, and experiments were conducted between 1:1 and 1:100. Changes in the flow rate ratio inevitably lead to changes in the content of safflower seed oil in the cosmetic emulsion. This adjustment was based on the assumption that the oil phase contained 0.5 wt% of the oil, with the flow rate ratio being the only variable. During the experiments, it was found that when the flow rate ratio was in the range of 1:1 to 1:5, the oil phase proportion was too high, and the shear force provided by the water phase was insufficient to break down the high-viscosity safflower seed oil to the nanoscale, forming a micron-sized coarse emulsion, which easily resulted in stratification and precipitation. While a flow rate ratio of 1:30 to 1:100 could produce a nanoscale cosmetic emulsion, the proportion of safflower seed oil was too low, resulting in insufficient effectiveness in practical use. Therefore, it is preferable to control the flow rate ratio between 1:5 and 1:30 to increase the safflower seed oil content in the feed. To further ensure the safflower seed oil content and to ensure the production of nano-sized cosmetic emulsions, it is preferable to control the oil-water two-phase flow rate ratio at 1:20.

[0099] Based on the scheme of Example 4 above, the ratio of polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers is 4:1. The hydrophilic-lipophilic balance (HLB) value of polyglycerol-10 oleate is 12, while that of the polyglycerol-2 oleic acid mixed emulsifier is 6. At the 4:1 ratio, the synergistic effect of high-HLB and low-HLB emulsifiers is achieved. The high-HLB component rapidly reduces interfacial tension and promotes emulsification, while the low-HLB component embeds into the interfacial film, increasing film density and steric hindrance. This ensures both nanoscale emulsification and long-term stability with no significant changes for more than 30 days. When the ratio is lower than 4:1, for example, at 3:1, the cosmetic emulsion is highly hydrophilic, resulting in excessive stretching of the interfacial film and insufficient film strength. When the ratio is reduced to 2:1, droplet coalescence easily occurs during long-term storage (30 days). Experiments have shown that at this ratio, the average diameter of the cosmetic emulsion increases by 30% within 30 days, failing to meet the requirements for long-term stable storage. When the ratio is higher than 4:1, such as 5:1, the high lipophilicity makes it difficult to disperse stably in the system. When the ratio increases to 10:1, layering and precipitation will occur within a short period of time. The higher the ratio, the faster the layering and precipitation occur, which may even occur within a few hours. However, by changing the total mass fraction of the polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier, and maintaining a 4:1 ratio with a total mass fraction in the range of 1wt%-10wt%, a cosmetic emulsion of good quality can be obtained.

[0100] Example 9:

[0101] This embodiment nine provides a method for the mass production of safflower seed oil cosmetic emulsion based on micro-nanofluidics, including the following steps:

[0102] S1. Prepare the oil phase by mixing 0.5wt% safflower seed oil with 2wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirring until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0103] S2. Prepare the aqueous phase by dissolving 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution.

[0104] S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:20, the total flow rate is 133.2 mL / min, and the operating temperature is 60℃.

[0105] S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain 1.0wt% safflower seed oil cosmetic emulsion.

[0106] The cosmetic emulsion collected in step S4 has an average particle size of 192 nm and a PDI value of 0.219. The production rate is 200 mL / 1.5 min. To facilitate control of the total flow rate, the total flow rate can be controlled within the range of 50 mL / min to 500 mL / min.

[0107] Comparative Example 1:

[0108] A conventional stirring method for preparing a 0.5 wt% safflower seed oil cosmetic emulsion includes the following steps:

[0109] S1. Oil phase preparation: 0.5wt% safflower seed oil is mixed with 2wt% polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifiers and stirred until completely dissolved to obtain a homogeneous oil phase mixed solution.

[0110] S2. Aqueous phase preparation: Dissolve 15wt% 1,3-butanediol and 2wt% glycerol in distilled water and stir until clear to obtain an aqueous mixed solution.

[0111] S3. Emulsification by stirring: Emulsification is carried out by conventional stirring; the oil phase solution obtained in step S1 and the aqueous phase solution obtained in step S2 are mixed in a small bottle and then stirred in a homogenizer for 30 minutes.

[0112] S4. Collection and Output: Collect the emulsion to obtain a 0.5wt% safflower seed oil cosmetic emulsion prepared by conventional stirring.

[0113] The cosmetic emulsion obtained in step S4 of Comparative Example 1 had an average particle size of 475.2 nm and a PDI of 0.36.

[0114] Comparing Example 4 and Comparative Example 1, the average particle size of the cosmetic emulsion obtained in Example 4 is significantly lower than that in Comparative Example 1. The average particle size of the cosmetic emulsion in Comparative Example 1 is nearly seven times that of Example 4, indicating a significant improvement in the technical solution of Example 4. Furthermore, the PDI of Example 4 is 0.19, while that of Comparative Example 1 is 0.36. The cosmetic emulsion in Example 4 has a smaller particle size distribution range, more uniform particle size, and more consistent performance, making it easier to control production quality and ensure stable and controllable effects.

[0115] like Figure 5 and Figure 6 As shown, when the cosmetic emulsion of Comparative Example 1 was left to stand at 48°C, its average particle size decreased on day 1 and day 30, while the PDI value increased by 0.036.

Claims

1. A method for preparing a safflower seed oil cosmetic emulsion based on micro / nanofluidics, characterized in that, Includes the following steps: S1. Prepare the oil phase by mixing 0.2wt%-1wt% of safflower seed oil, 1wt%-10wt% of polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier in a total mass ratio to obtain an oil phase mixed solution. S2. Prepare an aqueous phase by dissolving 5 wt%-25 wt% of water-soluble excipients 1,3-butanediol and 1 wt%-10 wt% of glycerol in distilled water and stirring until clear to obtain an aqueous mixed solution. S3. Micro-nanofluidic emulsification: Precision emulsification is performed using a three-dimensional micro-nanofluidic chip system. The oil phase solution obtained in step S1 is connected to the oil phase inlet of the chip, and the aqueous phase solution obtained in step S2 is connected to the aqueous phase inlet of the chip. The oil phase and aqueous phase are injected separately by independently controlled precision injection pumps, and shearing and mixing are performed in the micro-nanofluidic channel. The oil-water two-phase flow rate ratio is 1:5~1:30, and the operating temperature is 25℃-65℃. S4. Collection and Output: Collect the cosmetic emulsion flowing out of the chip outlet to obtain safflower seed oil cosmetic emulsion.

2. The method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 1, characterized in that, Within the micro / nano fluid control channel, the total flow rate of the oil-water two phases is 200µL / min-20000µL / min.

3. The method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 2, characterized in that, When used in laboratory preparation, the total flow rate of the oil-water two-phase system is 1040-1380 µL / min when the safflower seed oil content is 0.5 wt%.

4. The method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 2, characterized in that, When used in mass production, if the safflower seed oil content is 0.5 wt%, the total flow rate of the oil-water two-phase system is 50-500 mL / min.

5. The method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 1, characterized in that, The ratio of polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier is 2:1 to 10:

1.

6. The method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 1, characterized in that, The downstream channel at the junction of the oil and water phases in the micro / nano fluid control chip includes sections with different cross-sectional areas. These different cross-sectional areas promote the mixing of the liquids and are used to reduce the average particle size of cosmetic emulsions.

7. The method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 1, characterized in that, The micro-nano fluidic chip system includes a three-dimensional channel in which the oil phase and the water phase converge and assemble to form a cosmetic emulsion.

8. The method for preparing a safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 7, characterized in that, The three-dimensional channel includes several X-shaped, H-shaped, or a combination of both hybrid units. Multiple liquid confluence points are formed through the combination of X-shaped and H-shaped hybrid units, increasing the number of liquid confluence shearing operations within the micro / nanofluidic chip.

9. A safflower seed oil cosmetic emulsion based on micro / nanofluidics, characterized in that, The preparation method according to any one of claims 1-8 is used to obtain safflower seed oil with a mass ratio of 0.2wt%-1wt%, the mass ratio of the polyglycerol-10 oleate and polyglycerol-2 oleic acid mixed emulsifier is 2wt%, the mass ratio of 1,3-butanediol is 15wt%, the mass ratio of glycerol is 2wt%, and the remainder is distilled water.

10. A safflower seed oil cosmetic emulsion based on micro-nano fluidization according to claim 9, characterized in that, The safflower seed oil content is 0.5 wt%.

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