Camellia-based skin care product and preparation method thereof

Abstract

The invention relates to the technical field of cosmetics, in particular to a camellia-based skin care product and a preparation method thereof. The invention discloses a preparation method of a camellia-based skin care product, which comprises the following steps: mixing glycerol, triethanolamine, lauryl sodium sulfate and water to obtain a water phase; the preparation method comprises the following steps: mixing stearic acid, hexadecanol, cetostearyl alcohol, isopropyl palmitate, wool fat, olive oil, glyceryl monostearate and polydimethylsiloxane to obtain an oil-phase substrate; preparing oleic acid modified chitosan as gel, mixing the oleic acid modified chitosan with camellia oleosa seed oil, and reacting by taking glutaraldehyde as a cross-linking agent to prepare camellia oleosa-based oil gel; and finally, mixing the oil-phase substrate, the water phase and the oil-tea-based oil gel to obtain the oil-tea-based skin care product. The prepared oil-tea-based skin care product is excellent in heat resistance, cold resistance and stability, and high in somatosensory comfort during use.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, in particular to a camellia oil-based skin care product and a preparation method thereof. Background Art

[0002] Camellia oleifera, along with oil palm, olive, and coconut, is considered one of the world's four major woody oil-bearing tree species and a major woody oil crop in my country. Mature camellia seeds undergo a series of processing steps to produce camellia oil, rich in monounsaturated fatty acids. Because the ratio of various fatty acids in camellia oil is comparable to that of Western olive oil and its general composition is similar, it has earned the reputation of "Oriental Olive Oil" and has become a popular edible oil.

[0003] Camellia oleifera seed oil is a non-drying oil. In addition to various fatty acids, it also contains rich fat-soluble vitamins and antioxidants, which can effectively resist skin oxidative aging and ultraviolet damage to the skin. Therefore, it is applied to skin care products to improve skin luster, maintain skin health, delay skin aging, and effectively resist skin cell aging, spots, wrinkles and other phenomena caused by factors such as oxidation and ultraviolet radiation. Patent CN202211378743.3 discloses a natural antioxidant compound skin care product using camellia oleifera seed oil as a base oil. By adding licorice extract and citric acid to camellia oleifera seed oil, the antioxidant capacity of camellia oleifera seed oil during preparation and storage is protected. However, skin care products are mostly in the form of emulsions, and the emulsification effect of the product directly affects the long-term storage stability and efficacy. Products with unstable emulsification are often prone to stratification of the water phase and the oil phase, which accelerates the oxidation and deterioration of the active ingredients and even breeds bacteria and other organisms, leading to corruption and deterioration and producing odor.

[0004] Patent CN201811456060.9 provides a camellia oil sunscreen skin care product and its preparation method. The oil gel is prepared by beeswax, vitamin E and camellia oil, and mixed with an oil phase base and an aqueous phase base, thereby changing the mechanical properties of the oil phase and converting it into a more complex aqueous phase-gel two-phase system. Beeswax forms a dense hydrophobic film on the surface of the skin, reducing water loss, thereby achieving a moisturizing effect. However, this technical solution also has drawbacks. Beeswax not only reduces the breathability of the skin, but also brings an excessively "greasy feeling" to the skin of some consumers, affecting the user experience. Therefore, it is very necessary to provide a new camellia-based skin care product based on the existing technology. Summary of the Invention

[0005] The object of the present invention is to provide a camellia oil-based skin care product and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a camellia oil-based skin care product, comprising the following steps: Step 1: Mix glycerol, triethanolamine, citric acid, sodium lauryl sulfate, and water at 60-70°C to obtain an aqueous phase; Step 2: Mix stearic acid, cetyl alcohol, cetearyl alcohol, isopropyl palmitate, lanolin, olive oil, glyceryl monostearate, and polydimethylsiloxane at 60-70°C to obtain an oil phase base; Step 3: Dispersing the chitosan-based gel and camellia oil in water, adding citric acid to adjust the pH to 5.5-6, ultrasonically dispersing for 30-40 minutes, adding glutaraldehyde, stirring at 800-1000 rpm for 1-2 hours, increasing the speed to 16000-20000 rpm and homogenizing for 3-5 minutes, and freeze-drying to remove ethanol to obtain a camellia-based oil gel; Step 4: At 25~30℃, add the oil phase base to the water phase, maintain a stirring speed of 100~200rpm, stir for 15~30min, add the camellia oil gel, increase the speed to 800~1000rpm, and continue stirring for 5~10min to obtain the camellia oil-based skin care product.

[0007] Furthermore, in step 1, the amounts of the components in the aqueous phase are, by weight, 7 to 9 parts of glycerol, 0.5 to 0.73 parts of triethanolamine, 1.6 to 2.2 parts of sodium lauryl sulfate, 0.3 to 0.5 parts of citric acid, and 30 to 33 parts of water.

[0008] Furthermore, in step 2, the amounts of the components in the oil phase base, by weight, are 4 to 6 parts of stearic acid, 1.5 to 2 parts of hexadecanol, 1 to 1.5 parts of cetearyl alcohol, 3 to 4 parts of isopropyl palmitate, 0.3 to 0.5 parts of lanolin, 1 to 2 parts of olive oil, 1 to 2 parts of glyceryl monostearate, and 0.5 to 1.2 parts of polydimethylsiloxane.

[0009] Furthermore, in step 3, the weight ratio of the chitosan-based gelling agent, camellia oil, and glutaraldehyde is (1.6-2.8): (45-55): (0.5-0.8).

[0010] Furthermore, in step 3, the preparation method of the chitosan-based gel comprises the following steps: S1: adding chitosan to a sodium hydroxide solution, swelling it at 25-30°C for 2-3 hours, sealing and freezing it at -5-0°C for 8-10 hours, and thawing it to obtain alkali-swollen chitosan; mixing the alkali-swollen chitosan with isopropyl alcohol, adding propylene oxide with tetramethylammonium hydroxide as a catalyst, stirring for 1-2 hours, heating it in a microwave oven at 60-70°C for 30-60 minutes, letting it stand and cooling it, collecting the precipitate, washing it with isopropyl alcohol, and drying it to obtain O-hydroxypropyl chitosan; dissolving the O-hydroxypropyl chitosan in water to obtain an O-hydroxypropyl chitosan solution; S2: dissolving oleic acid in water to obtain an oleic acid dispersion solution; adding a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide as a coupling agent to the oleic acid dispersion solution and performing an activation treatment to obtain an activated oleic acid dispersion solution; S3: adding the activated oleic acid dispersion solution to the O-hydroxypropyl chitosan solution to obtain a mixed solution, reacting the mixed solution in the dark at 25-30° C. for 5-6 hours, dialyzing for 60-72 hours, and then freeze-drying in a vacuum to obtain a chitosan-based gel.

[0011] Furthermore, in S1, the concentration of the sodium hydroxide solution is 40 wt.%.

[0012] Furthermore, in S2, the activation treatment temperature is 40-50°C, and the activation treatment time is 30-60 minutes.

[0013] Furthermore, in S3, oleic acid reacted with O-hydroxypropyl chitosan at a molar ratio of carboxyl group to amino group of (0.26-0.48):1.

[0014] Furthermore, in step 4, the oil phase base, the water phase, and the camellia oil-based oil gel are mixed in a weight ratio of (10-13): (28-36): (22-27).

[0015] Compared with the prior art, the present invention achieves the following beneficial effects: A chitosan-based gelling agent is mixed with camellia seed oil to prepare a camellia-based oleogel, which is then mixed with an aqueous and oily base phase to create a camellia-based skincare product. Compared to traditional skincare products, the camellia-based skincare product produced by the present invention exhibits superior heat and cold resistance, as well as stability. Prior art oleogels often use waxy gelling agents, whereas the present invention utilizes chitosan molecules reacting with a crosslinker to form a three-dimensional crosslinked network that encapsulates the oil phase (camellia seed oil). This results in a stronger structure, higher porosity, and improved breathability. Unlike waxy materials, chitosan molecules have a stronger hydration capacity, forming a "water-absorbing layer" on the skin surface that absorbs water for long-lasting moisturization, rather than slowing evaporation through an impermeable oil layer. This improves breathability while reducing the "greasy" feel, providing consumers with a more refreshing user experience.

[0016] Conventional chitosan has weak lipophilicity and low solubility, making it difficult to prepare oil gels. The present invention first reacts alkali-swollen chitosan with propylene oxide to prepare O-hydroxypropyl chitosan, thereby improving the solubility of chitosan. Oleic acid is then selectively grafted onto the chitosan through the reaction of amino and carboxyl groups on the O-hydroxypropyl chitosan, improving its lipophilicity. Since camellia oil contains a very high oleic acid content, modifying chitosan with oleic acid effectively improves the compatibility of chitosan with camellia oil, facilitating the formation of a uniform and stable oil gel.

[0017] Furthermore, it should be noted that the chitosan-based gelling agent is prepared by controlling the reaction of oleic acid with O-hydroxypropyl chitosan at a carboxyl group to amino group molar ratio of (0.26-0.48):1. A low oleic acid grafting amount results in insufficient chitosan lipophilicity, while a high oleic acid grafting amount, on the one hand, leads to greater steric hindrance of the chitosan molecular side chains, hindering the reaction of the side chain amino groups with the cross-linking agent glutaraldehyde, resulting in poor coating properties of the resulting oleogel, and the product may experience problems such as water and oil seepage, oil-water separation, and poor storage stability. Furthermore, it also affects the water absorption capacity of the chitosan, resulting in poor moisturizing effect. DETAILED DESCRIPTION

[0018] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0019] Materials and sources used in the present invention: Chitosan is from Qingdao Bozhi Huili Biotechnology Co., Ltd., with a deacetylation degree of ≥95%, and the remaining materials are commercially available products.

[0020] Example 1: A method for preparing a camellia oil-based skin care product, comprising the following steps: Step 1: Mix 7 g of glycerol, 0.5 g of triethanolamine, 0.3 g of citric acid, 1.6 g of sodium lauryl sulfate, and 30 g of water at 60° C. to obtain an aqueous phase; Step 2: At 60°C, mix 4g of stearic acid, 1.5g of cetyl alcohol, 1g of cetearyl alcohol, 3g of isopropyl palmitate, 0.3g of lanolin, 1g of olive oil, 1g of glyceryl monostearate, and 0.5g of polydimethylsiloxane to obtain an oil phase base; Step 3: 1.6 g of chitosan-based gel and 45 g of camellia oil were dispersed in water, citric acid was added to adjust the pH to 5.5, and 0.5 g of glutaraldehyde was added after ultrasonic dispersion for 30 min. After stirring at 800 rpm for 2 h, the speed was increased to 16,000 rpm and homogenized for 5 min. The ethanol was removed by freeze drying to obtain a camellia-based oil gel; Wherein, the preparation method of chitosan-based gel is: S1: chitosan was added to a 40 wt.% sodium hydroxide solution, swelled at 25°C for 3 hours, sealed and frozen at -5°C for 8 hours, and thawed to obtain alkali-swollen chitosan; the alkali-swollen chitosan was mixed with isopropyl alcohol, tetramethylammonium hydroxide was used as a catalyst, propylene oxide was added and stirred for 1 hour, microwave-heated to 60°C for 60 minutes, allowed to stand and cooled, and the precipitate was collected, washed with isopropyl alcohol, and dried to obtain O-hydroxypropyl chitosan; the O-hydroxypropyl chitosan was dissolved in water to obtain an O-hydroxypropyl chitosan solution; S2: dissolving oleic acid in water to obtain an oleic acid dispersion solution; adding a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide as a coupling agent to the oleic acid dispersion solution, heating to 40° C. for activation treatment for 60 minutes to obtain an activated oleic acid dispersion solution; S3: adding the activated oleic acid dispersion solution to the O-hydroxypropyl chitosan solution to obtain a mixed solution, reacting the mixed solution in the dark at 25° C. for 6 hours, dialyzing for 60 hours, and then freeze-drying in a vacuum to obtain a chitosan-based gel; wherein, in the mixed solution, oleic acid reacts with O-hydroxypropyl chitosan at a molar ratio of carboxyl group to amino group of 0.26:1; Step 4: At 25°C, add the oil phase base to the water phase, maintain a stirring speed of 100 rpm, stir for 30 minutes, add the camellia oil gel, increase the speed to 800 rpm, and continue stirring for 10 minutes to obtain a camellia oil-based skin care product, wherein the weight ratio of the oil phase base, water phase, and camellia oil gel is 10:28:22.

[0021] Example 2: A method for preparing a camellia oil-based skin care product, comprising the following steps: Step 1: Mix 8 g of glycerol, 0.67 g of triethanolamine, 0.4 g of citric acid, 1.9 g of sodium lauryl sulfate, and 32 g of water at 65° C. to obtain an aqueous phase; Step 2: At 65°C, mix 5.5g of stearic acid, 1.8g of cetyl alcohol, 1.3g of cetearyl alcohol, 3.8g of isopropyl palmitate, 0.42g of lanolin, 1.6g of olive oil, 1.6g of glyceryl monostearate, and 1g of polydimethylsiloxane to obtain an oil phase base; Step 3: Disperse 2.3 g of chitosan-based gel and 52 g of camellia oil in water, add citric acid to adjust the pH to 5.8, ultrasonically disperse for 35 min, add 0.7 g of glutaraldehyde, stir at 950 rpm for 1.5 h, increase the speed to 18,000 rpm and homogenize for 4.5 min, and freeze-dry to remove ethanol to obtain a camellia-based oil gel; Wherein, the preparation method of chitosan-based gel is: S1: chitosan was added to a 40 wt.% sodium hydroxide solution, swelled at 28°C for 2.5 hours, sealed and frozen at -2°C for 9 hours, and thawed to obtain alkali-swollen chitosan; the alkali-swollen chitosan was mixed with isopropyl alcohol, tetramethylammonium hydroxide was used as a catalyst, propylene oxide was added, stirred for 1.5 hours, microwave-heated to 65°C for 40 minutes, allowed to stand, cooled, and the precipitate was collected, washed with isopropyl alcohol, and dried to obtain O-hydroxypropyl chitosan; O-hydroxypropyl chitosan was dissolved in water to obtain an O-hydroxypropyl chitosan solution; S2: dissolving oleic acid in water to obtain an oleic acid dispersion solution; adding a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide as a coupling agent to the oleic acid dispersion solution, heating to 45° C. for activation treatment for 40 minutes to obtain an activated oleic acid dispersion solution; S3: adding the activated oleic acid dispersion solution to the O-hydroxypropyl chitosan solution to obtain a mixed solution, reacting the mixed solution in the dark at 28° C. for 5.5 hours, dialyzing for 65 hours, and then freeze-drying in a vacuum to obtain a chitosan-based gel; wherein, in the mixed solution, oleic acid reacts with O-hydroxypropyl chitosan at a molar ratio of carboxyl group to amino group of 0.35:1; Step 4: At 30°C, add the oil phase base to the water phase, maintain a stirring speed of 150 rpm, stir for 20 minutes, add the camellia oil-based oil gel, increase the speed to 950 rpm, and continue stirring for 8 minutes to obtain a camellia oil-based skin care product, wherein the weight ratio of the oil phase base, water phase, and camellia oil gel is 11:32:25.

[0022] Example 3: A method for preparing a camellia oil-based skin care product, comprising the following steps: Step 1: Mix 9 g of glycerol, 0.73 g of triethanolamine, 0.5 g of citric acid, 2.2 g of sodium lauryl sulfate, and 33 g of water at 70° C. to obtain an aqueous phase; Step 2: At 70°C, mix 6g of stearic acid, 2g of cetyl alcohol, 1.5g of cetearyl alcohol, 4g of isopropyl palmitate, 0.5g of lanolin, 2g of olive oil, 2g of glyceryl monostearate, and 1.2g of polydimethylsiloxane to obtain an oil phase base; Step 3: 2.8 g of chitosan-based gel and 55 g of camellia oil were dispersed in water, citric acid was added to adjust the pH to 6, and after ultrasonic dispersion for 40 min, 0.8 g of glutaraldehyde was added. After stirring at 1000 rpm for 1 h, the speed was increased to 20000 rpm and homogenized for 3 min. The ethanol was removed by freeze drying to obtain a camellia-based oil gel; Wherein, the preparation method of chitosan-based gel is: S1: chitosan was added to a 40 wt.% sodium hydroxide solution, swelled at 30°C for 2 hours, sealed and frozen at 0°C for 10 hours, and thawed to obtain alkali-swollen chitosan; the alkali-swollen chitosan was mixed with isopropyl alcohol, tetramethylammonium hydroxide was used as a catalyst, propylene oxide was added and stirred for 2 hours, microwave-heated to 70°C for 30 minutes, allowed to stand and cooled, and the precipitate was collected, washed with isopropyl alcohol, and dried to obtain O-hydroxypropyl chitosan; O-hydroxypropyl chitosan was dissolved in water to obtain an O-hydroxypropyl chitosan solution; S2: dissolving oleic acid in water to obtain an oleic acid dispersion solution; adding a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide as a coupling agent to the oleic acid dispersion solution, heating to 50° C. for activation treatment for 30 minutes to obtain an activated oleic acid dispersion solution; S3: adding the activated oleic acid dispersion solution to the O-hydroxypropyl chitosan solution to obtain a mixed solution, reacting the mixed solution in the dark at 30° C. for 5 hours, dialyzing for 72 hours, and then freeze-drying in a vacuum to obtain a chitosan-based gel; wherein, in the mixed solution, oleic acid reacts with O-hydroxypropyl chitosan at a molar ratio of carboxyl group to amino group of 0.48:1; Step 4: At 30°C, add the oil phase base to the water phase, maintain a stirring speed of 200 rpm, stir for 15 minutes, add the camellia oil-based oil gel, increase the speed to 1000 rpm, and continue stirring for 5 minutes to obtain a camellia oil-based skin care product, wherein the weight ratio of the oil phase base, water phase, and camellia oil gel is 13:36:27.

[0023] Comparative Example 1: Camellia oleifera seed oil is directly mixed with an oil phase base and an aqueous phase to prepare a camellia oleifera-based skin care product.

[0024] Step 1: Mix 7 g of glycerol, 0.5 g of triethanolamine, 0.3 g of citric acid, 1.6 g of sodium lauryl sulfate, and 30 g of water at 60° C. to obtain an aqueous phase; Step 2: At 60°C, mix 4g of stearic acid, 1.5g of cetyl alcohol, 1g of cetearyl alcohol, 3g of isopropyl palmitate, 0.3g of lanolin, 1g of olive oil, 1g of glyceryl monostearate, and 0.5g of polydimethylsiloxane to obtain an oil phase base; Step 3: At 25°C, add the oil phase base to the water phase, maintain a stirring speed of 100 rpm, stir for 30 minutes, add camellia oil-based camellia seed oil, increase the speed to 800 rpm, and continue stirring for 10 minutes to obtain a camellia-based skin care product, wherein the weight ratio of the oil phase base, water phase, and camellia seed oil is 10:28:22.

[0025] Comparative Example 2: Chitosan was dissolved in a 2 wt.% acetic acid solution to obtain a 3 wt.% chitosan acetic acid solution. The chitosan acetic acid solution was used instead of the chitosan-based gel prepared in the present invention. The other parameters were the same as those in Example 2.

[0026] Step 1: Mix 8 g of glycerol, 0.67 g of triethanolamine, 0.4 g of citric acid, 1.9 g of sodium lauryl sulfate, and 32 g of water at 65°C to obtain an aqueous phase; Step 2: At 65°C, mix 5.5g of stearic acid, 1.8g of cetyl alcohol, 1.3g of cetearyl alcohol, 3.8g of isopropyl palmitate, 0.42g of lanolin, 1.6g of olive oil, 1.6g of glyceryl monostearate, and 1g of polydimethylsiloxane to obtain an oil phase base; Step 3: Disperse 2.3 g of chitosan-based gel (calculated based on the weight of chitosan in the chitosan acetate solution) and 52 g of camellia oil in water, add citric acid to adjust the pH to 5.8, ultrasonically disperse for 35 minutes, then add 0.7 g of glutaraldehyde, stir at 950 rpm for 1.5 hours, then increase the speed to 18,000 rpm and homogenize for 4.5 minutes, and freeze-dry to remove ethanol to obtain a camellia-based oil gel; Step 4: At 30°C, add the oil phase base to the water phase, maintain a stirring speed of 150 rpm, stir for 20 minutes, add the camellia oil-based oil gel, increase the speed to 950 rpm, and continue stirring for 8 minutes to obtain a camellia oil-based skin care product, wherein the weight ratio of the oil phase base, water phase, and camellia oil gel is 11:32:25.

[0027] Comparative Example 3: The grafting amount of oleic acid in the chitosan-based gel was increased, and the other parameters were the same as those in Example 3.

[0028] Step 1: Mix 9 g of glycerol, 0.73 g of triethanolamine, 0.5 g of citric acid, 2.2 g of sodium lauryl sulfate, and 33 g of water at 70° C. to obtain an aqueous phase; Step 2: At 70°C, mix 6g of stearic acid, 2g of cetyl alcohol, 1.5g of cetearyl alcohol, 4g of isopropyl palmitate, 0.5g of lanolin, 2g of olive oil, 2g of glyceryl monostearate, and 1.2g of polydimethylsiloxane to obtain an oil phase base; Step 3: 2.8 g of chitosan-based gel and 55 g of camellia oil were dispersed in water, citric acid was added to adjust the pH to 6, and after ultrasonic dispersion for 40 min, 0.8 g of glutaraldehyde was added. After stirring at 1000 rpm for 1 h, the speed was increased to 20000 rpm and homogenized for 3 min. The ethanol was removed by freeze drying to obtain a camellia-based oil gel; Wherein, the preparation method of chitosan-based gel is: S1: chitosan was added to a 40 wt.% sodium hydroxide solution, swelled at 30°C for 2 hours, sealed and frozen at 0°C for 10 hours, and thawed to obtain alkali-swollen chitosan; the alkali-swollen chitosan was mixed with isopropyl alcohol, tetramethylammonium hydroxide was used as a catalyst, propylene oxide was added and stirred for 2 hours, microwave-heated to 70°C for 30 minutes, allowed to stand and cooled, and the precipitate was collected, washed with isopropyl alcohol, and dried to obtain O-hydroxypropyl chitosan; O-hydroxypropyl chitosan was dissolved in water to obtain an O-hydroxypropyl chitosan solution; S2: dissolving oleic acid in water to obtain an oleic acid dispersion solution; adding a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide as a coupling agent to the oleic acid dispersion solution, heating to 50° C. for activation treatment for 30 minutes to obtain an activated oleic acid dispersion solution; S3: adding the activated oleic acid dispersion solution to the O-hydroxypropyl chitosan solution to obtain a mixed solution, reacting the mixed solution in the dark at 30° C. for 5 hours, dialyzing for 72 hours, and then freeze-drying in a vacuum to obtain a chitosan-based gel; wherein, in the mixed solution, oleic acid reacts with O-hydroxypropyl chitosan at a molar ratio of carboxyl group to amino group of 0.55:1; Step 4: At 30°C, add the oil phase base to the water phase, maintain a stirring speed of 200 rpm, stir for 15 minutes, add the camellia oil-based oil gel, increase the speed to 1000 rpm, and continue stirring for 5 minutes to obtain a camellia oil-based skin care product, wherein the weight ratio of the oil phase base, water phase, and camellia oil gel is 13:36:27.

[0029] Experiment: The samples prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested, and the experimental results are shown in Table 1. Skin care product cold resistance, heat resistance and stability test: Refer to QBT1857-2013 moisturizing cream testing standard test, test respectively at 40℃ for one week and then cool to 25℃, store at -10℃ for one week and then warm to 25℃, and stir magnetically (2000rpm) for 1 hour to observe whether there is stratification, water or oil seepage.

[0030] Test on the physical comfort of skin care products: 12 testers were selected for a single-blind test. Before each test, the testers were required to clean their faces with clean water and dry them with a towel. While keeping their faces clean, 2g of sample were evenly applied to the face. The four indicators of smoothness, stickiness, extensibility and long-lasting skin feel (2 hours after use) were used to rate the satisfaction of each group of samples from 1 to 10 (the highest satisfaction score was 10 points and the lowest was 1 point). The arithmetic mean of the four indicators was used as the tester's personal score for the group of samples. The 12 personal scores obtained from the test of each group of samples were sorted from low to high. After removing the highest score and the lowest score, the arithmetic mean of the remaining data was used as the final score for the physical comfort of the group of samples.

[0031] Conclusion: The data from Examples 1 to 3 show that the skin care products prepared by the present invention have excellent cold and heat resistance and stability, and provide users with high physical comfort when using them. The data from Example 1 and Comparative Example 1 show that the skin care products prepared by adding camellia oil-based oil gel have better performance than those prepared by directly adding camellia oil seed oil; the data from Example 2 and Comparative Example 2 show that the chitosan-based gel prepared by the present invention has better lipophilicity than the chitosan gel, and no oil leakage occurs; the data from Example 3 and Comparative Example 3 show that after increasing the amount of oleic acid grafted in the chitosan-based gel, the crosslinking degree of the chitosan-based gel decreases, and the stability of the oil gel deteriorates, resulting in oil leakage during storage.

[0032] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a camellia oil-based skin care product, characterized in that: The following steps are involved: Step 1: Mix glycerol, triethanolamine, citric acid, sodium lauryl sulfate, and water at 60-70°C to obtain an aqueous phase; Step 2: Mix stearic acid, cetyl alcohol, cetearyl alcohol, isopropyl palmitate, lanolin, olive oil, glyceryl monostearate, and polydimethylsiloxane at 60-70°C to obtain an oil phase base; Step 3: Dispersing the chitosan-based gel and camellia oil in water, adding citric acid to adjust the pH to 5.5-6, ultrasonically dispersing for 30-40 minutes, adding glutaraldehyde, stirring at 800-1000 rpm for 1-2 hours, increasing the speed to 16000-20000 rpm and homogenizing for 3-5 minutes, and freeze-drying to remove ethanol to obtain a camellia-based oil gel; Step 4: At 25~30℃, add the oil phase base to the water phase, maintain a stirring speed of 100~200rpm, stir for 15~30min, add the camellia oil gel, increase the speed to 800~1000rpm, and continue stirring for 5~10min to obtain the camellia oil-based skin care product.

2. The method for preparing a camellia oil-based skin care product according to claim 1, characterized in that: In step 1, the amounts of the components in the aqueous phase are, by weight, 7 to 9 parts of glycerol, 0.5 to 0.73 parts of triethanolamine, 0.3 to 0.5 parts of citric acid, 1.6 to 2.2 parts of sodium lauryl sulfate, and 30 to 33 parts of water.

3. The method for preparing a camellia oil-based skin care product according to claim 1, characterized in that: In step 2, the amounts of the components in the oil phase base, by weight, are 4 to 6 parts of stearic acid, 1.5 to 2 parts of hexadecanol, 1 to 1.5 parts of cetearyl alcohol, 3 to 4 parts of isopropyl palmitate, 0.3 to 0.5 parts of lanolin, 1 to 2 parts of olive oil, 1 to 2 parts of glyceryl monostearate, and 0.5 to 1.2 parts of polydimethylsiloxane.

4. The method for preparing a camellia oil-based skin care product according to claim 1, characterized in that: In step 3, the weight ratio of chitosan-based gelling agent, camellia oil and glutaraldehyde is (1.6-2.8): (45-55): (0.5-0.8).

5. The method for preparing a camellia oil-based skin care product according to claim 1, characterized in that: In step 3, the preparation method of the chitosan-based gel comprises the following steps: S1: adding chitosan to a sodium hydroxide solution, swelling it at 25-30°C for 2-3 hours, sealing and freezing it at -5-0°C for 8-10 hours, and thawing it to obtain alkali-swollen chitosan; mixing the alkali-swollen chitosan with isopropyl alcohol, adding propylene oxide with tetramethylammonium hydroxide as a catalyst, stirring for 1-2 hours, heating it in a microwave oven at 60-70°C for 30-60 minutes, letting it stand and cooling it, collecting the precipitate, washing it with isopropyl alcohol, and drying it to obtain O-hydroxypropyl chitosan; dissolving the O-hydroxypropyl chitosan in water to obtain an O-hydroxypropyl chitosan solution; S2: dissolving oleic acid in water to obtain an oleic acid dispersion solution; adding a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide as a coupling agent to the oleic acid dispersion solution and performing an activation treatment to obtain an activated oleic acid dispersion solution; S3: adding the activated oleic acid dispersion solution to the O-hydroxypropyl chitosan solution to obtain a mixed solution, reacting the mixed solution in the dark at 25-30° C. for 5-6 hours, dialyzing for 60-72 hours, and then freeze-drying in a vacuum to obtain a chitosan-based gel.

6. The method for preparing a camellia oil-based skin care product according to claim 5, characterized in that: In S1, the concentration of the sodium hydroxide solution is 40 wt.%.

7. The method for preparing a camellia oil-based skin care product according to claim 5, characterized in that: In S2, the activation treatment temperature is 40~50°C, and the activation treatment time is 30~60min.

8. The method for preparing a camellia oil-based skin care product according to claim 5, characterized in that: In S3, oleic acid reacted with O-hydroxypropyl chitosan at a carboxyl group to amino group molar ratio of (0.26-0.48):

1.

9. The method for preparing a camellia oil-based skin care product according to claim 1, characterized in that: In step 4, the oil phase base, the water phase, and the camellia oil-based oil gel are mixed in a weight ratio of (10-13): (28-36): (22-27).

10. The camellia oleifera-based skin care product prepared according to the preparation method according to any one of claims 1 to 9.

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