A Camellia Seed Oil Composition Containing Tetrahydrocurcumin and Its Application

Abstract

This invention relates to a camellia seed oil composition containing tetrahydrocurcumin and its application. The composition comprises tetrahydrocurcumin, camellia seed oil, phenylpropanol, and diisopropyl adipate. The present invention involves mixing the above components, heating and stirring until homogeneous, and then cooling to obtain the camellia seed oil composition containing tetrahydrocurcumin. This invention successfully solves the problems of poor stability and low active ingredient content in tetrahydrocurcumin compositions, improving the bioavailability of tetrahydrocurcumin in the prepared microemulsions, and can be applied in the preparation of cosmetics.

Description

Technical Field

[0001] This invention belongs to the field of cosmetics, specifically relating to a camellia seed oil composition containing tetrahydrocurcumin and its application. Background Technology

[0002] Curcumin, an active ingredient extracted from turmeric, possesses anti-inflammatory, antioxidant, antiviral, and antitumor properties and is widely used in the food, health, and pharmaceutical industries. However, curcumin exhibits strong coloring properties and is sensitive to light, heat, heavy metal ions, and pH, thus it is generally used as a colorant in cosmetics in very small quantities. In contrast, tetrahydrocurcumin, as the most active and primary metabolite of curcumin produced in vivo, is more stable and has a lighter color, making it more widely used in cosmetics. Currently, although the chemical stability of tetrahydrocurcumin has been significantly improved, its water solubility and bioavailability remain low. Therefore, phospholipids and other materials are often used to encapsulate tetrahydrocurcumin to enhance its bioavailability.

[0003] Camellia seed oil is an edible oil obtained from the seeds of the Camellia oleifera tree (Camellia L.), belonging to the category of vegetable oils. According to the *Classic of Mountains and Seas*, my country has cultivated Camellia oleifera for over 2300 years. Furthermore, camellia seed oil has good thermal stability and is not easily oxidized or deteriorated, making it an excellent oil for cosmetics. In tea-producing areas, camellia seed oil is commonly used to prevent infant eczema and winter skin itching, as well as for women's beauty, skincare, and hair care. Camellia seed oil has a triglyceride structure, a large molecular weight, and low polarity, meaning it can only support some fat-soluble active ingredients and cannot support alcohol-soluble active ingredients such as tetrahydrocurcumin. Additionally, patent application number 202211695584.X, "A Microemulsion and Its Preparation Method," provides a method for preparing a camellia seed oil microemulsion, but it can only support some oil-soluble active ingredients and is incapable of supporting alcohol-soluble active ingredients, which limits its application in cosmetics.

[0004] Patent application number 201380066964.X (rejected) discloses compositions and / or articles with improved solubility of solid active substances, comprising isosorbide diester, solid cosmetic active substances (including tetrahydrocurcumin), and dermatologically acceptable carriers (including camellia seed oil). The "Catalogue of Used Cosmetic Ingredients (2021 Edition)" lists only isosorbide dimethyl ether as an isosorbide-related ingredient, while isosorbide diester is a general term for a class of substances not included in the "Catalogue of Used Cosmetic Ingredients (2021 Edition)". Furthermore, the patent does not include any examples related to camellia seed oil, and the amount of isosorbide diester added is relatively large. As described in Example 2 of the patent, when tetrahydrocurcumin is used as a solid cosmetic active substance, the amount of isosorbide dioctanoate (a type of isosorbide diester) added is 32 times that of tetrahydrocurcumin, making it almost unusable for encapsulation preparation, let alone for loading camellia seed oil.

[0005] In summary, loading camellia seed oil with a high content of tetrahydrocurcumin is a very challenging research topic. This invention aims to construct a composition system to address this challenge and improve the bioavailability of tetrahydrocurcumin. Summary of the Invention

[0006] To address the challenge of loading tetrahydrocurcumin into camellia seed oil, this invention provides a camellia seed oil composition containing tetrahydrocurcumin and its applications. This invention combines camellia seed oil, tetrahydrocurcumin, phenylpropanol, and diisopropyl adipate to prepare a camellia seed oil composition containing tetrahydrocurcumin, successfully solving the problems of poor composition stability (especially low-temperature stability) and low active ingredient content.

[0007] The objective of this invention can be achieved through the following methods:

[0008] In a first aspect, the present invention provides a camellia seed oil composition containing tetrahydrocurcumin, comprising the following components by mass fraction:

[0009]

[0010] In one embodiment of the present invention, the tetrahydrocurcumin has a mass fraction of 3-11%.

[0011] In one embodiment of the present invention, the camellia seed oil has a mass fraction of 5-25%.

[0012] As one embodiment of the present invention, the mass ratio of tetrahydrocurcumin to camellia seed oil is 1:4-8 or 1:0.2-0.8.

[0013] In some preferred embodiments, the mass ratio of the tetrahydrocurcumin to camellia seed oil includes 1:4, 1:8, and 1:0.5.

[0014] In one embodiment of the present invention, the phenylpropanol has a mass fraction of 35-45%.

[0015] In one embodiment of the present invention, the mass fraction of diisopropyl adipate is 35-45%.

[0016] As one embodiment of the present invention, no more than 3 wt% of oil-soluble active ingredients, such as tocopherol derivatives, ascorbic acid derivatives, retinol derivatives, camellia flower extract, camellia leaf extract, camellia seed extract, etc., may also be added to the composition.

[0017] Secondly, the present invention provides a method for preparing a camellia seed oil composition containing tetrahydrocurcumin, comprising the following steps: mixing camellia seed oil, tetrahydrocurcumin, phenylpropanol, and diisopropyl adipate, heating and stirring until uniform, and cooling to obtain a camellia seed oil composition containing tetrahydrocurcumin.

[0018] In one embodiment of the present invention, the heating temperature is 60-80°C.

[0019] Thirdly, the present invention also provides the application of a camellia seed oil composition containing tetrahydrocurcumin in the preparation of cosmetics.

[0020] As one embodiment of the present invention, the application includes: using a camellia seed oil composition containing tetrahydrocurcumin as the oil phase, and preparing a microemulsion using a low-temperature emulsification process.

[0021] As one embodiment of the present invention, the method for preparing the microemulsion includes: using a camellia seed oil composition containing tetrahydrocurcumin as the oil phase, mixing PPG-13-decyltetradecyl alcohol polyether-24 with glycerol as the alcohol phase, and using water as the aqueous phase; adding the oil phase to the alcohol phase in batches, heating and stirring to obtain an oil-alcohol mixed phase, then adding the aqueous phase to the oil-alcohol mixed phase in batches, stirring evenly, and cooling to room temperature to obtain a camellia seed oil microemulsion containing tetrahydrocurcumin.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention constructs a composition of camellia seed oil, tetrahydrocurcumin, phenylpropanol and diisopropyl adipate, which successfully solves the problems of poor stability and low content of active ingredients in the composition.

[0024] (2) This invention utilizes the high solubility of phenylpropanol for tetrahydrocurcumin; and further increases the solubility of tetrahydrocurcumin by adding diisopropyl adipate, while blending camellia seed oil and phenylpropanol to obtain a clear and uniform oil phase.

[0025] (3) All components in the composition of the present invention are cosmetic raw materials listed in the "Catalogue of Used Cosmetic Raw Materials (2021 Edition)" and can be used in various cosmetics.

[0026] (4) The microemulsion prepared by the composition of the present invention effectively solves the problem of low bioavailability of tetrahydrocurcumin. Attached Figure Description

[0027] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 This is a particle size distribution diagram of Application Example 1. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, providing detailed implementation methods and specific operating procedures, which will help those skilled in the art to further understand the present invention. It should be noted that the scope of protection of the present invention is not limited to the following embodiments; any adjustments and improvements made under the concept of the present invention are all within the scope of protection of the present invention.

[0030] Example 1

[0031] Weigh 4g of camellia seed oil, 1g of tetrahydrocurcumin (5.88%), 6g of phenylpropanol, and 6g of diisopropyl adipate into a 100g beaker, heat and stir at 65℃ until homogeneous; then cool to room temperature and stand at 3℃ for 36h without precipitation.

[0032] Example 2

[0033] Weigh 4g of camellia seed oil, 0.5g of tetrahydrocurcumin (3.03%), 6g of phenylpropanol, and 6g of diisopropyl adipate into a 100g beaker, heat and stir at 65℃ until homogeneous; then cool to room temperature and stand at 3℃ for 36h without precipitation.

[0034] Example 3

[0035] 4g of camellia seed oil, 1.5g of tetrahydrocurcumin (8.57%), 6g of phenylpropanol, and 6g of diisopropyl adipate were weighed into a 100g beaker and heated and stirred at 65℃ until homogeneous. After cooling to room temperature, 0.38g of solid was precipitated after standing at 3℃ for 36h. The precipitated solid was identified as tetrahydrocurcumin.

[0036] Example 4

[0037] 4g of camellia seed oil, 2g of tetrahydrocurcumin (11.11%), 6g of phenylpropanol, and 6g of diisopropyl adipate were weighed into a 100g beaker and heated and stirred at 65℃ until homogeneous. After cooling to room temperature, 0.90g of solid was precipitated after standing at 3℃ for 36h. The precipitated solid was confirmed to be tetrahydrocurcumin.

[0038] Example 5

[0039] 1g of camellia seed oil, 2g of tetrahydrocurcumin (13.33%), 6g of phenylpropanol, and 6g of diisopropyl adipate were weighed into a 100g beaker and heated and stirred at 65℃ until homogeneous. After cooling to room temperature, 0.23g of solid was precipitated after standing at 3℃ for 36h. The precipitated solid was confirmed to be tetrahydrocurcumin.

[0040] Example 6

[0041] Weigh 1g of camellia seed oil, 2g of tetrahydrocurcumin (10.53%), 8g of phenylpropanol, and 8g of diisopropyl adipate into a 100g beaker, heat and stir at 65℃ until homogeneous; then cool to room temperature and stand at 3℃ for 36h without precipitation.

[0042] Example 7

[0043] Weigh 3.52g of camellia seed oil, 0.26g of red camellia flower extract (1.53%), 0.22g of red camellia leaf extract (1.29%), 1g of tetrahydrocurcumin, 6g of diisopropyl adipate, and 6g of phenylpropanol into a 100g beaker, heat and stir at 65°C until homogeneous; then cool to room temperature and stand at 3°C ​​for 36 hours without precipitation.

[0044] Comparative Example 1

[0045] 2g of tetrahydrocurcumin and 8g of phenylpropanol were weighed into a 100g beaker and heated at 65℃ with stirring until homogeneous. The mixture was then cooled to room temperature and allowed to stand at 3℃ for 36 hours without precipitation. This indicates that phenylpropanol has excellent solubility for tetrahydrocurcumin, presumably due to the principle of "like dissolves like," as both tetrahydrocurcumin and phenylpropanol contain benzene ring structures and are structurally similar.

[0046] Comparative Example 2

[0047] 3g of tetrahydrocurcumin and 8g of phenylpropanol were weighed into a 100g beaker and heated and stirred at 65°C until homogeneous. After cooling to room temperature, 0.78g of solid was precipitated after standing at 3°C ​​for 36 hours. The precipitated solid was confirmed to be tetrahydrocurcumin.

[0048] Comparative Example 3

[0049] 2g of tetrahydrocurcumin and 8g of diisopropyl adipate were weighed into a 100g beaker and heated and stirred at 65℃ until homogeneous. After cooling to room temperature, 1.24g of solid was precipitated after standing at 3℃ for 36h. The precipitated solid was confirmed to be tetrahydrocurcumin.

[0050] Comparative Example 4

[0051] Weigh 1g of camellia seed oil and 8g of phenylpropanol into a 100g beaker, heat and stir at 65℃ until homogeneous; then cool to room temperature, the liquid becomes turbid, which indicates that camellia seed oil and phenylpropanol are incompatible and a clear and homogeneous oil phase cannot be obtained.

[0052] Comparative Example 5

[0053] Weigh 1g of camellia seed oil and 8g of diisopropyl adipate into a 100g beaker, heat and stir at 65℃ until homogeneous; then cool to room temperature. The liquid is clear and transparent, which indicates that camellia seed oil and diisopropyl adipate are compatible and can produce a clear and homogeneous oil phase.

[0054] Comparative Example 6

[0055] 1g of camellia seed oil, 2g of tetrahydrocurcumin (10.53%), 8g of phenylpropanol, and 8g of ethylhexylglycerin were weighed into a 100g beaker and heated at 65℃ with stirring until homogeneous. After cooling to room temperature, the mixture was allowed to stand at 3℃ for 36 hours, resulting in the precipitation of 0.23g of solid. Analysis confirmed that the precipitated solid was tetrahydrocurcumin. This indicates that diisopropyl adipic acid has better solubility for tetrahydrocurcumin than ethylhexylglycerin.

[0056] Comparative Example 7

[0057] 1g of camellia seed oil, 2g of tetrahydrocurcumin (10.53%), 8g of phenylethanol, and 8g of ethylhexylglycerin were weighed into a 100g beaker and heated at 65℃ with stirring until homogeneous. After cooling to room temperature, the mixture was allowed to stand at 3℃ for 36 hours, resulting in the precipitation of 0.58g of solid. Analysis confirmed that the precipitated solid was tetrahydrocurcumin. This indicates that phenylpropanol has a better solubility for tetrahydrocurcumin than phenylethanol. Furthermore, compared to phenylpropanol, phenylethanol has a very strong odor, limiting its application in the cosmetics field.

[0058] Comparative Example 8

[0059] 1g of camellia seed oil, 2g of tetrahydrocurcumin (18.18%), and 8g of phenylpropanol were weighed into a 100g beaker and heated at 65°C with stirring until homogeneous. After cooling to room temperature, the liquid became turbid, which was due to the incompatibility between camellia seed oil and phenylpropanol. After standing at 3°C ​​for 36 hours, 0.45g of solid precipitated, which was confirmed by analysis to be tetrahydrocurcumin. Compared with Example 6, it can be seen that diisopropyl adipate is necessary, not only increasing the solubility of tetrahydrocurcumin but also harmonizing camellia seed oil and phenylpropanol to obtain a clear and homogeneous oil phase.

[0060] Comparative Example 9

[0061] 1g of camellia seed oil, 2g of tetrahydrocurcumin (18.18%), and 8g of diisopropyl adipate were weighed into a 100g beaker and heated and stirred at 65°C until homogeneous. The mixture was then cooled to room temperature and allowed to stand at 3°C ​​for 36 hours, resulting in the precipitation of 1.36g of solid. Analysis confirmed that the precipitated solid was tetrahydrocurcumin. Compared to Example 6, it can be seen that phenylpropanol has excellent solubility for tetrahydrocurcumin.

[0062] Application Example 1

[0063] Referring to the low-temperature emulsification process of the patent "A Microemulsion and its Preparation Method" (application number 202211695584.X), a microemulsion was prepared from the composition of Example 6, as detailed below:

[0064] The microemulsion was prepared entirely at 65°C: 1g of camellia seed oil, 2g of tetrahydrocurcumin (10.53%), 8g of phenylpropanol, and 8g of diisopropyl adipate were weighed into a 100g beaker and heated and stirred at 65°C until homogeneous; this was recorded as the oil phase. 20g of PPG-13-decyltetradecyl alcohol polyether-24 and 20g of glycerol were weighed into a 150mL beaker and heated and stirred until homogeneous at 65°C; this was recorded as the alcohol phase. 41g of water was weighed into a 100mL beaker and heated and stirred until homogeneous at 65°C; this was recorded as the aqueous phase. The oil phase was then added to the alcohol phase in batches, and the mixture was heated and stirred until homogeneous at 65°C. Finally, the aqueous phase was added to the oil-alcohol mixture in batches, stirred until homogeneous, and cooled to room temperature to obtain the camellia seed oil microemulsion containing tetrahydrocurcumin. The microemulsion was then diluted with water to prepare a 1% solution, and its stability at 3°C ​​was observed. The particle size was determined using a Bettersize 3000 particle size analyzer, and the transdermal absorption efficiency was determined using the Franz diffusion cell method.

[0065] The particle size distribution of Application Example 1 is as follows Figure 1 As shown in Table 1, the transdermal absorption results are as follows.

[0066] Table 1. Transdermal absorption results in Application Example 1

[0067] project Application Example 1 24-hour penetration rate, % 1.24 24-hour intradermal retention rate, % 0.80 24-hour skin residue rate, % 81.22

[0068] By analyzing the appendix Figure 1 Table 1 shows that the camellia seed oil microemulsion containing tetrahydrocurcumin prepared using Example 1 is clear and transparent in appearance, and no precipitation occurred in the diluted solution after storage at 3°C ​​for 36 hours. In addition, particle size analysis results show that the microemulsion has a relatively uniform particle size, with an average particle size of less than 100 nm. Transdermal absorption results show that the microemulsion prepared using Example 1 can achieve a transdermal rate of 1.24% and an intradermal retention rate of 0.80%. Since the intradermal retention rate needs to be measured by crushing pig skin to extract tetrahydrocurcumin, the actual intradermal retention rate should be higher than 0.80%.

[0069] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A camellia seed oil composition containing tetrahydrocurcumin, characterized in that, The components are composed of the following mass fractions. composition: Tetrahydrocurcumin 1-8.57%, Camellia seed oil 1-30%, Phenylacetol 25-50%, Diisopropyl adipic acid 25-50%.

2. The camellia seed oil composition according to claim 1, characterized in that, The mass fraction of the tetrahydrocurcumin is 3-8.57%.

3. The camellia seed oil composition according to claim 1, characterized in that, The camellia seed oil has a mass fraction of 5-25%.

4. The camellia seed oil composition according to claim 1, characterized in that, The mass fraction of the phenylpropanol is 35-45%.

5. The camellia seed oil composition according to claim 1, characterized in that, The mass fraction of the diisopropyl adipate is 35-45%.

6. A method for preparing the camellia seed oil composition according to any one of claims 1-5, characterized in that, The process includes the following steps: mixing tetrahydrocurcumin, camellia seed oil, phenylpropanol, and diisopropyl adipate, heating and stirring until homogeneous, and then cooling to obtain a camellia seed oil composition containing tetrahydrocurcumin.

7. The preparation method according to claim 6, characterized in that, The heating temperature is 60-80℃.

8. A cosmetic comprising the camellia seed oil composition according to any one of claims 1-5, characterized in that, The cosmetic may also contain no more than 3 wt% of oil-soluble active ingredients, including at least one of tocopherol derivatives, ascorbic acid derivatives, retinol derivatives, camellia flower extract, camellia leaf extract, and camellia seed extract.

9. The use of a camellia seed oil composition containing tetrahydrocurcumin as described in claim 1 in the preparation of cosmetics.

10. The application according to claim 9, characterized in that, The application is as follows: using a camellia seed oil composition containing tetrahydrocurcumin as the oil phase, a microemulsion is prepared by a low-temperature emulsification process.

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