A skin-resident type of cream with soothing repair, moisturizing and its preparation method

Abstract

The application belongs to the technical field of skin care products, and specifically discloses a skin resident ointment with soothing repair and moisturizing and a preparation method thereof. The ointment comprises the following raw materials in parts by mass: 15-20 parts of an oil phase, 60-75 parts of an aqueous phase, 3-8 parts of an emulsifier, 0.5-2 parts of a preservative, 2-5 parts of a eugenol cyclodextrin inclusion compound, 3-6 parts of angelica oligosaccharide, and 4-8 parts of a fermented extracellular polysaccharide concentrate. The application reduces the irritation of eugenol and prolongs the residence by cyclodextrin inclusion, improves the transdermal permeability by enzymatic hydrolysis of angelica polysaccharide, and forms a biological adhesive film by replacing a synthetic thickening agent with fermentation residues, so that a three-level polysaccharide network is constructed through hydrogen bond crosslinking, and the synergistic improvement of soothing, moisturizing and residence is realized.

Description

Technical Field

[0001] This invention belongs to the field of skin care technology, specifically relating to a skin-retaining ointment with soothing, repairing, moisturizing and skin-moisturizing properties, and its preparation method. Background Technology

[0002] Leave-on ointments are a type of cosmetic formulation that is applied to the skin surface and remains on for an extended period without rinsing. They are widely used in soothing, repairing, and moisturizing the skin. The efficacy of these ointments depends not only on the bioactivity of the active ingredients but also on their residence time on the skin surface, their ability to penetrate the superficial stratum corneum, and the stability of the ointment itself on damaged skin. In recent years, with the increasing consumer preference for naturally derived active ingredients, plant-derived ingredients, such as clove bud extract and angelica root extract, have been widely used in leave-on ointment formulations. However, current technologies for processing these active ingredients are relatively crude, failing to fully realize their potential efficacy and even raising safety concerns.

[0003] A biotechnology company has incorporated clove bud extract and angelica extract into the ointment base in their publicly disclosed product formula, using their raw forms. Eugenol, the main active ingredient in clove buds, exists in this formula in a free state. While eugenol possesses clear anti-inflammatory activity, it has a low irritation threshold upon direct skin contact, easily causing a burning sensation. Furthermore, its small molecular weight and high volatility result in a short residence time on the skin surface, making it easily washed away by sweat or wiped away by clothing, thus hindering the sustained soothing effect. More importantly, free eugenol is prone to oxidation and discoloration during ointment storage, affecting product appearance and consumer acceptance. Current technologies address the high irritation of eugenol by reducing its dosage to mitigate safety risks; however, reducing the dosage weakens the anti-inflammatory effect, creating a conflict between efficacy and safety.

[0004] The main active ingredient in Angelica sinensis root is Angelica polysaccharide, with a molecular weight typically ranging from 50 to 200 kDa. Current techniques directly add Angelica polysaccharide to ointments in its original macromolecular form. However, due to the molecular weight retention effect of lipid channels in the stratum corneum cells, this high molecular weight polysaccharide has difficulty penetrating the stratum corneum, forming only a superficial moisturizing film on the skin surface and failing to penetrate deep into the superficial stratum corneum to promote barrier repair. Furthermore, the high molecular weight polysaccharide has poor solubility in aqueous ointments and easily separates from other components in the ointment matrix, affecting product stability. There are currently no reports on the targeted degradation of Angelica polysaccharide into oligosaccharides with suitable transdermal molecular weights and their synergistic construction with other carriers to create a resident network.

[0005] In terms of ointment base design, traditional skin-retaining ointments are prone to loss of moisture and hydration when the skin is dry, flaky, or slightly damaged. This is because the surface of the stratum corneum is uneven, and the ointment is easily washed away by friction or water, resulting in the loss of active ingredients before they can penetrate, leading to insufficient moisturizing longevity. To address this issue, existing technologies often use synthetic thickeners such as carbomer and xanthan gum to increase the viscosity of the ointment. However, excessive use of synthetic thickeners can easily cause breakouts or skin irritation. Furthermore, their thickening mechanism involves the physical entanglement of polymer chains, which lacks specific interaction with skin keratin, making it difficult to form a continuous and stable adhesion film on the uneven surface of damaged skin. At the same time, the dense gel network formed by synthetic thickeners may hinder the release and penetration of active ingredients.

[0006] In summary, existing technologies have failed to address the technical problems of free eugenol's irritation, easy loss, and easy oxidation; the large molecular weight and poor transdermal permeability of angelica polysaccharides; and the poor adhesion of traditional ointments to damaged skin and their reliance on synthetic thickeners. Therefore, there is a need to design a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties, along with its preparation method. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, a skin-retaining ointment with soothing, repairing, moisturizing and skin-nourishing properties and its preparation method are provided.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A skin-residual ointment with soothing, repairing, moisturizing and skin-nourishing properties, comprising the following raw materials in parts by weight: 15-20 parts oil phase, 60-75 parts aqueous phase, 3-8 parts emulsifier, 0.5-2 parts preservative, 2-5 parts eugenol cyclodextrin inclusion complex, 3-6 parts angelica oligosaccharide, and 4-8 parts fermented extracellular polysaccharide concentrate.

[0009] The oil phase comprises squalane and jojoba oil, wherein the mass ratio of squalane to jojoba oil is 2-3:1.

[0010] The aqueous phase comprises deionized water, glycerol, and 1,3-propanediol, wherein the mass ratio of glycerol to 1,3-propanediol is 2-3:1; and the mass ratio of deionized water to glycerol is 10-15:1.

[0011] The emulsifier comprises cetearyl alcohol and cocoyl glucoside, wherein the mass ratio of cetearyl alcohol to cocoyl glucoside is 1:1 to 1:2.

[0012] The preservative comprises 1,2-hexanediol and p-hydroxyacetophenone, wherein the mass ratio of 1,2-hexanediol to p-hydroxyacetophenone is 0.5-1.0:0.3-0.5.

[0013] A method for preparing a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties, comprising the following steps: Step 1: Extract volatile oil from clove buds by steam distillation, collect eugenol fraction and distillation residue, and use the distillation residue to prepare dried clove residue; Step 2: Dissolve hydroxypropyl-β-cyclodextrin in deionized water to prepare a saturated aqueous solution, and add the eugenol fraction collected in step 1 dropwise under stirring at 45-55℃ to obtain eugenol cyclodextrin inclusion complex powder. The third step is to prepare Angelica oligosaccharides by slicing Angelica root and prepare Angelica root water extraction residue from the filter residue. Step 4: Mix the dried clove residue obtained in Step 1 with the dried Angelica root water extract residue obtained in Step 3 to prepare a fermented extracellular polysaccharide concentrate. Step 5: Mix squalane and jojoba oil and heat to 70-75°C. Add cetearyl alcohol and stir until melted and homogeneous. Set the product aside. Step 6: Heat deionized water to 75-80℃, add cocoyl glucoside, glycerol, and 1,3-propanediol, stir to dissolve and obtain an aqueous phase. The resulting product is ready for use. Step 7: Under stirring and maintaining a temperature of 70-75℃, slowly add the product obtained in Step 5 to the product obtained in Step 6 while stirring. Then, homogenize and circulate the mixture 2-3 times under a pressure of 20-30MPa to obtain an emulsion. Then, stir and cool down. When the emulsion temperature drops to 40-45℃, add the Angelica oligosaccharide obtained in Step 3 and the eugenol cyclodextrin inclusion complex powder obtained in Step 2, and stir to dissolve. Continue to cool down to 35-38℃ and add the fermented extracellular polysaccharide concentrate obtained in Step 4, and stir for 1-2 hours. Finally, cool down to below 35℃, add 1,2-hexanediol and p-hydroxyacetophenone, stir evenly, defoam, and fill into containers to obtain a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties.

[0014] In the first step, the specific parameters for steam distillation are: distillation temperature 100-110℃, time 2-4h; The steps for preparing dried clove residue from the distillation residue include: vacuum drying the distillation residue at 60-80℃ until the moisture content is not higher than 10%, and pulverizing it through a 40-60 mesh sieve to obtain dried clove residue.

[0015] In the second step, the mass ratio of eugenol to hydroxypropyl-β-cyclodextrin is 1:5-1:7; The specific parameters for the inclusion treatment are: stirring and inclusion for 2-3 hours, standing crystallization at 4°C for 12-16 hours, filtration, and vacuum drying at 40-50°C.

[0016] In the formulation design of skin-soothing ointments, eugenol, as the main active ingredient of clove buds, has confirmed anti-inflammatory activity. However, free eugenol has a small molecular weight, high volatility, short residence time on the skin surface, and is prone to causing burning irritation upon direct contact, as well as oxidation and discoloration during storage. Existing technologies typically add it directly to the ointment in its original form or simply reduce the amount added to alleviate irritation, but it is difficult to balance efficacy and safety. This application uses hydroxypropyl-β-cyclodextrin to encapsulate the eugenol fraction, forming an eugenol cyclodextrin inclusion complex. From a molecular structure perspective, hydroxypropyl-β-cyclodextrin is truncated conical in shape, with a hydrophobic microenvironment inside the cavity and hydrophilic properties on the outside due to hydroxypropyl substitution. The benzene ring structure of eugenol can be embedded in this hydrophobic cavity, stably bound through van der Waals forces and hydrophobic interactions, while the hydroxyl groups on the outer wall of the cyclodextrin face the aqueous phase, enabling the originally lipid-soluble eugenol to acquire water solubility and be uniformly dispersed in the aqueous phase of the ointment. After application, as moisture on the stratum corneum surface evaporates, the moisture gradient drives the inclusion complex to gradually dissociate, allowing eugenol to be released slowly and avoiding the sudden release of free eugenol. Simultaneously, the cyclodextrin shell physically isolates eugenol from oxygen in the environment, preventing the phenolic hydroxyl groups on the benzene ring from direct exposure to the oxidizing environment, thus delaying discoloration. Furthermore, the abundant hydroxyl groups on the cyclodextrin outer wall act as hydrogen bond donors, forming hydrogen bonds with the hydroxyl and carboxyl groups on the long polysaccharide chains, anchoring the inclusion complex within the polysaccharide network of the ointment and reducing the risk of it being washed away by water.

[0017] In the third step, the preparation of Angelica oligosaccharides and Angelica root water extract residue includes the following steps: Angelica root slices are added, 8-10 times the amount of deionized water is added for reflux extraction for 2 hours, filtered, and the filtrate is concentrated under reduced pressure to a relative density of 1.10-1.20 to obtain a concentrated solution. Pectinase is added, the pH is adjusted to 4.0-4.5, and enzymatic hydrolysis is performed at 50-55℃ for 2-3 hours. The solution is then inactivated in a boiling water bath for 10 minutes, centrifuged, and the supernatant is collected. Three times the volume of anhydrous ethanol is added for alcohol precipitation. The precipitate is washed 2-3 times with 85%-95% ethanol, and the supernatant is discarded after each centrifugation. The solution is then vacuum dried to obtain Angelica oligosaccharides. The filter residue is vacuum dried at 60-80℃ until the moisture content is not higher than 10%, and then pulverized through a 40-60 mesh sieve to obtain dried Angelica root water extract residue. The amount of pectinase used is 5-10 U per milliliter of concentrated solution.

[0018] While the irritation and stability issues of eugenol have been improved through inclusion complexation, the application obstacles of another key active ingredient in ointments still need to be addressed. The polysaccharides in Angelica sinensis root typically have a high molecular weight, making it difficult to penetrate the intercellular lipid channels of the stratum corneum. They can only form a superficial moisturizing film on the skin surface, and their large long chains are prone to phase separation from other components in aqueous ointments. Existing technologies for processing them are relatively crude. This application utilizes pectinase to perform targeted enzymatic hydrolysis of the concentrated aqueous extract of Angelica sinensis root to prepare Angelica sinensis oligosaccharides. Pectinase can recognize and cleave the glycosidic bonds in the polysaccharide molecular chains, degrading the long chains into oligosaccharide fragments. With the reduced molecular weight of these fragments, steric hindrance decreases, allowing them to penetrate to the superficial layer along the intercellular lipid channels of the stratum corneum. The hydroxyl groups retained on their chains form hydrogen bonds with the amino and carbonyl groups of keratin, constructing a hydration layer and promoting barrier repair. Meanwhile, the reduced molecular weight increases the solubility of Angelica oligosaccharides in the aqueous phase, increases the flexibility of the molecular chains, improves compatibility with other polar components in the ointment matrix, and reduces the problem of uneven ointment composition caused by phase separation.

[0019] In the fourth step, the preparation of the fermented extracellular polysaccharide concentrate includes the following steps: The dried clove residue obtained in the first step and the dried angelica root water extract residue obtained in the third step are mixed at a mass ratio of 1:1-2:1 to obtain residue; deionized water is added to prepare a slurry, wherein the mass ratio of the residue to deionized water is 1:6-1:10; the pH is adjusted to 4.5-5.5; cellulase is added; enzymatic hydrolysis is performed at 45-55℃ for 2-4 hours; and the enzyme is then inactivated at 80-90℃ for 10-15 minutes. The mixture was cooled to 35-38℃, glucose was added, and *Lactobacillus plantarum* was inoculated. Anaerobic fermentation was carried out at 35-38℃ for 48-72 hours. The fermentation broth was inactivated by boiling water bath, centrifuged, and the supernatant was collected. The supernatant was concentrated under reduced pressure to a solid content of 8%-15% to obtain a concentrated fermented extracellular polysaccharide broth. The amount of cellulase used was 5-15 U per gram of residue, the glucose-to-residue mass ratio was 1:15-1:25, and the inoculation amount of *Lactobacillus plantarum* was 1.5%-3% of the residue mass.

[0020] After the permeability and compatibility issues of Angelica polysaccharides were improved through enzymatic hydrolysis, the physical adhesion of the ointment to damaged skin became a new technical bottleneck. When the skin is dry and flaky, the surface is uneven, and traditional ointments are easily wiped away or washed away by water. Moreover, the synthetic thickeners relied upon by existing technologies do not have specific interaction with skin keratin and are difficult to form a stable adhesion film.

[0021] This application utilizes *Lactobacillus plantarum* to anaerobic ferment dried clove residue and dried angelica root water extract residue pretreated with cellulase to prepare a concentrated fermented extracellular polysaccharide solution. Cellulase first hydrolyzes the cellulose and hemicellulose in the residue into oligosaccharides and monosaccharides, providing a fermentable carbon source for *Lactobacillus plantarum*. Under anaerobic conditions, *Lactobacillus plantarum* metabolizes carbohydrates through glycolysis and phosphatidylcholinesterase pathways, secreting extracellular polysaccharides mainly composed of dextran and fructan. These polysaccharide long chains contain numerous hydroxyl groups and a small number of carboxyl groups. The hydroxyl groups can act as hydrogen bond donors and acceptors, forming multiple hydrogen bonds with the peptide bonds, side-chain amino groups, and lipid head groups of keratin on the skin surface, generating a mild bioadhesive force. This adhesion is based on the weak interaction of intermolecular hydrogen bonds, rather than chemical bonding. The ointment can form a breathable film on the skin surface. When subjected to external force, the hydrogen bonds within the film can dynamically break and recombine, giving the ointment a certain degree of flexibility and abrasion resistance. Simultaneously, this bioadhesive network is relatively loose, allowing active ingredients to diffuse and release within the network gaps without being hindered by dense structures.

[0022] After the individual functions of the aforementioned active ingredients are improved, the synergistic effect of these three components in the ointment becomes crucial to determining the overall efficacy. Eugenol cyclodextrin inclusion complex, angelica oligosaccharide, and fermented extracellular polysaccharide form a tertiary polysaccharide network in the aqueous phase of the ointment through hydrogen bonding. The fermented extracellular polysaccharide, acting as a macromolecular backbone, forms a spatial network with its long chains, providing physical support for adhesion and film formation. The cyclodextrin inclusion complex, through hydrogen bonding between its outer hydroxyl groups and the long polysaccharide chains, anchors itself at network nodes, acting as a medium-molecular-weight carrier to delay the release of eugenol. The smaller molecular weight of angelica oligosaccharide fills the network gaps, penetrating to the superficial stratum corneum to participate in barrier repair.

[0023] The three components form a molecular weight gradient distribution at the physical level, with macromolecules anchored to the skin surface, medium molecules providing sustained-release active ingredients, and small molecules penetrating and repairing, creating a progressive functional synergy. To facilitate the construction of this network, this application uses squalane and jojoba oil to form the oil phase. Squalane has a chemical structure similar to squalene in human sebum, exhibits good spreadability, and can form a lightweight sealing layer on the skin surface. Jojoba oil is a long-chain fatty acid ester with high compatibility with sebum and better breathability than traditional mineral oil. Together with the hydrated adhesion layer of the aforementioned tertiary polysaccharide network, they form a water-lipid biphase retention structure, reducing transdermal water loss.

[0024] The emulsifier is a blend of cetearyl alcohol and cocoyl glucoside. Cetearyl alcohol, a long-chain fatty alcohol, provides a melt backbone in the oil phase and, together with squalane and jojoba oil, constitutes the liquid crystal precursor in the oil phase. Cocoyl glucoside, an alkyl glycoside surfactant, contains multiple glycosidic hydroxyl groups at its hydrophilic end, exhibiting structural affinity for tertiary polysaccharide networks. It can form a stable liquid crystal layer at the oil-water interface, reducing interfacial tension and improving the emulsification stability and spreadability of the ointment. The preservative is a blend of 1,2-hexanediol and p-hydroxyacetophenone. The short-chain diol structure of 1,2-hexanediol can disrupt the permeability of microbial cell membranes, while the phenolic hydroxyl groups of p-hydroxyacetophenone can interfere with microbial redox processes. Both exert antibacterial effects in a weakly acidic aqueous phase and are less irritating than traditional preservatives, ensuring the shelf life and safety of the ointment.

[0025] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. This application uses hydroxypropyl-β-cyclodextrin to encapsulate eugenol fractions. Eugenol molecules are embedded in the hydrophobic cavities of the cyclodextrin, and the outward-facing hydroxyl groups on the cyclodextrin's outer wall increase water solubility. After application, it is gradually released along the moisture gradient of the stratum corneum, avoiding the burning irritation caused by direct contact of free eugenol with the skin. The cyclodextrin shell physically isolates eugenol, reducing oxygen contact and thus slowing down oxidative discoloration during storage. The abundant hydroxyl groups on the cyclodextrin's outer wall can form hydrogen bonds with the hydroxyl and carboxyl groups on the long chains of fermented extracellular polysaccharides, anchoring the inclusion complex within the polysaccharide network. This reduces the risk of it being washed away by sweat or lost through clothing wiping, prolonging the residence time of its anti-inflammatory activity on the skin surface.

[0026] 2. This application employs pectinase to perform targeted enzymatic hydrolysis of the concentrated aqueous extract of Angelica sinensis root, degrading the macromolecular polysaccharides into low-molecular-weight Angelica sinensis oligosaccharides. Even with the reduced molecular weight, the hydroxyl group density remains high, allowing it to penetrate the superficial stratum corneum and form a hydrogen-bonded hydration layer with keratin, promoting skin barrier repair. Compared to the original macromolecular polysaccharides, the solubility and dispersibility of Angelica sinensis oligosaccharides in the aqueous phase are significantly improved, reducing the risk of phase separation from other components of the ointment matrix and enhancing the overall stability of the ointment.

[0027] 3. This application utilizes *Lactobacillus plantarum* to anaerobic ferment dried clove residue and dried *Angelica sinensis* root water extract residue pretreated with cellulase, metabolizing them to produce high-molecular-weight fermented extracellular polysaccharides. These polysaccharide chains contain numerous hydroxyl groups and a small number of carboxyl groups, which can form multiple hydrogen bonds with keratin on the skin surface, generating mild bioadhesive forces. This allows the ointment to form a continuous film on the uneven surface of damaged skin, resisting wiping and water rinsing. This bioadhesive network can replace synthetic thickeners such as carbomer and xanthan gum, avoiding the potential problems of acne breakouts or irritation caused by synthetic thickeners. Furthermore, its relatively loose network structure does not hinder the release and penetration of active ingredients.

[0028] 4. In this application, eugenol cyclodextrin inclusion complex, angelica oligosaccharide, and fermented extracellular polysaccharide form a tertiary polysaccharide network through hydrogen bonding in the aqueous phase of the ointment. These three components are not simply mixed, but rather constitute a whole with a gradient molecular weight distribution. The fermented extracellular polysaccharide, acting as a macromolecular backbone, provides adhesion and film-forming functions; the cyclodextrin inclusion complex, acting as a medium-molecular-weight carrier, achieves sustained release; and the angelica oligosaccharide, as a small-molecule active ingredient, penetrates to the superficial layer of the stratum corneum. These three components form a progressive relationship of anchoring, sustained release, and penetration at the physical level, improving the residence time and utilization efficiency of the active ingredients on the skin surface. Squalane and jojoba oil form a lightweight sealing layer on the skin surface, which, together with the hydrated adhesion layer of the tertiary polysaccharide network, constitutes a water-lipid biphasic retention structure, further enhancing the moisturizing durability of the ointment. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating a method for preparing a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties according to the present invention. Figure 2 The graph shows the test results for the abrasion resistance, cumulative eugenol release, and oxidative stability of the present invention. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the specific embodiments of this application, the sources of various main raw materials are briefly described as follows: Clove buds: purchased from Jiangxi Xuesong Natural Medicinal Oil Co., Ltd.

[0032] Hydroxypropyl-β-cyclodextrin: purchased from Shandong Binzhou Zhiyuan Biotechnology Co., Ltd., CAS No. 128446-35-5.

[0033] Cellulase: Purchased from Chengdu Wanxiang Hongrun Biotechnology Co., Ltd., CAS No. 9012-54-8, food grade.

[0034] Pectinase: Purchased from Shandong Nuojie Biotechnology Co., Ltd., CAS No. 9032-75-1, food grade.

[0035] Lactobacillus plantarum: purchased from Beijing Zhongke Quality Inspection Biotechnology Co., Ltd., strain number CICC 6076.

[0036] Squalane: Purchased from Guangzhou Yinghong Chemical Co., Ltd., CAS No. 111-01-3.

[0037] Jojoba oil: purchased from Jiangxi Baicao Pharmaceutical Co., Ltd., CAS No. 61789-91-1.

[0038] Cetearyl alcohol: purchased from Nanjing Dongde Chemical Technology Co., Ltd., CAS No. 67762-27-0.

[0039] Coco-based glucoside: purchased from Guangzhou Yinghong Chemical Co., Ltd., CAS No. 141464-42-8.

[0040] Glycerin: Purchased from Jianmin Natural Fragrance Oil Factory, Jishui County, CAS No. 56-81-5.

[0041] 1,3-Propanediol: Purchased from Shanghai Hongzhuang Chemical Technology Co., Ltd., CAS No. 504-63-2.

[0042] 1,2-Hexanediol: Purchased from Shanghai Hongzhuang Chemical Technology Co., Ltd., CAS No. 6920-22-5.

[0043] p-Hydroxyacetophenone: Purchased from Guangdong Hainuo Kewei Biomedical Co., Ltd., CAS No. 99-93-4.

[0044] Glucose: Purchased from Hubei Rutian Biotechnology Co., Ltd., CAS No. 50-99-7.

[0045] Angelica sinensis: purchased from Fufeng Sinote Biotechnology Co., Ltd.

[0046] The technical solution of this application is as follows: A skin-residual ointment with soothing, repairing, moisturizing and skin-nourishing properties, comprising the following raw materials in parts by weight: 15-20 parts oil phase, 60-75 parts aqueous phase, 3-8 parts emulsifier, 0.5-2 parts preservative, 2-5 parts eugenol cyclodextrin inclusion complex, 3-6 parts angelica oligosaccharide, and 4-8 parts fermented extracellular polysaccharide concentrate.

[0047] The oil phase comprises squalane and jojoba oil, wherein the mass ratio of squalane to jojoba oil is 2-3:1.

[0048] The aqueous phase comprises deionized water, glycerol, and 1,3-propanediol, wherein the mass ratio of glycerol to 1,3-propanediol is 2-3:1; and the mass ratio of deionized water to glycerol is 10-15:1.

[0049] The emulsifier comprises cetearyl alcohol and cocoyl glucoside, wherein the mass ratio of cetearyl alcohol to cocoyl glucoside is 1:1 to 1:2.

[0050] The preservative comprises 1,2-hexanediol and p-hydroxyacetophenone, wherein the mass ratio of 1,2-hexanediol to p-hydroxyacetophenone is 0.5-1.0:0.3-0.5.

[0051] A method for preparing a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties, such as... Figure 1 As shown, the method includes the following steps: Step 1: Extract volatile oil from clove buds by steam distillation, collect eugenol fraction and distillation residue, and use the distillation residue to prepare dried clove residue; Step 2: Dissolve hydroxypropyl-β-cyclodextrin in deionized water to prepare a saturated aqueous solution, and add the eugenol fraction collected in step 1 dropwise under stirring at 45-55℃ to obtain eugenol cyclodextrin inclusion complex powder. The third step is to prepare Angelica oligosaccharides by slicing Angelica root and prepare Angelica root water extraction residue from the filter residue. Step 4: Mix the dried clove residue obtained in Step 1 with the dried Angelica root water extract residue obtained in Step 3 to prepare a fermented extracellular polysaccharide concentrate. Step 5: Mix squalane and jojoba oil and heat to 70-75°C. Add cetearyl alcohol and stir until melted and homogeneous. Set the product aside. Step 6: Heat deionized water to 75-80℃, add cocoyl glucoside, glycerol, and 1,3-propanediol, stir to dissolve and obtain an aqueous phase. The resulting product is ready for use. Step 7: Under stirring and maintaining a temperature of 70-75℃, slowly add the product obtained in Step 5 to the product obtained in Step 6 while stirring. Then, homogenize and circulate the mixture 2-3 times under a pressure of 20-30MPa to obtain an emulsion. Then, stir and cool down. When the emulsion temperature drops to 40-45℃, add the Angelica oligosaccharide obtained in Step 3 and the eugenol cyclodextrin inclusion complex powder obtained in Step 2, and stir to dissolve. Continue to cool down to 35-38℃ and add the fermented extracellular polysaccharide concentrate obtained in Step 4, and stir for 1-2 hours. Finally, cool down to below 35℃, add 1,2-hexanediol and p-hydroxyacetophenone, stir evenly, defoam, and fill into containers to obtain a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties.

[0052] In the first step, the specific parameters for steam distillation are: distillation temperature 100-110℃, time 2-4h; The steps for preparing dried clove residue from the distillation residue include: vacuum drying the distillation residue at 60-80℃ until the moisture content is not higher than 10%, and pulverizing it through a 40-60 mesh sieve to obtain dried clove residue.

[0053] In the second step, the mass ratio of eugenol to hydroxypropyl-β-cyclodextrin is 1:5-1:7; The specific parameters for the inclusion treatment are: stirring and inclusion for 2-3 hours, standing crystallization at 4°C for 12-16 hours, filtration, and vacuum drying at 40-50°C.

[0054] In the third step, the preparation of Angelica oligosaccharides and the aqueous extract residue of Angelica root includes the following steps: Angelica root slices are extracted by reflux with 8-10 times the amount of deionized water for 2 hours, filtered, and the filtrate is concentrated under reduced pressure to a relative density of 1.10-1.20 to obtain a concentrated solution. Pectinase is added, the pH is adjusted to 4.0-4.5, and enzymatic hydrolysis is performed at 50-55℃ for 2-3 hours. The solution is then inactivated in a boiling water bath for 10 minutes, cooled to room temperature, and centrifuged to collect the supernatant. The supernatant is ultrafiltered through an ultrafiltration membrane with a molecular weight cutoff of 3 kDa to remove small molecule salts and monosaccharide fragments produced by enzymatic hydrolysis, and the retentate is collected. Three volumes of anhydrous ethanol are added to the retentate for precipitation. The precipitate is washed 2-3 times with 85%-95% ethanol, and the supernatant is discarded after each centrifugation. The precipitate is then vacuum dried to obtain Angelica oligosaccharides. The filter residue is vacuum dried at 60-80℃ until the moisture content is no higher than 10%, pulverized through a 40-60 mesh sieve, and the dried aqueous extract residue of Angelica root is obtained. The amount of pectinase used is 5-10 U per milliliter of concentrate.

[0055] In the fourth step, the preparation of the fermented extracellular polysaccharide concentrate includes the following steps: The dried clove residue obtained in the first step and the dried angelica root water extract residue obtained in the third step are mixed at a mass ratio of 1:1-2:1 to obtain residue. Deionized water is added to prepare a slurry, with the mass ratio of residue to deionized water being 1:6-1:10. The pH is adjusted to 4.5-5.5, cellulase is added, and enzymatic hydrolysis is performed at 45-55℃ for 2-4 hours. The mixture is then heated to 80-90℃ for 10-15 minutes to inactivate the enzyme, cooled to 35-38℃, and glucose is added. Inoculate with *Lactobacillus plantarum* and anaerobic ferment at 35-38℃ for 48-72 hours. Inactivate the fermentation broth by boiling water bath and centrifuge to collect the supernatant. Add 2-3 times the volume of anhydrous ethanol to the supernatant, let stand at 4℃ for 12 hours, and centrifuge to collect the polysaccharide precipitate. Redissolve the precipitate in deionized water, place it in a dialysis bag with a molecular weight cutoff of 3.5 kDa, and dialyze in deionized water for 48 hours, changing the water every 8 hours to remove small molecule sugars, lactic acid, and salts. Concentrate the dialysate under reduced pressure to a solid content of 8%-15% to obtain the concentrated fermented extracellular polysaccharide solution. The amount of cellulase used is 5-15 U per gram of residue, the mass ratio of glucose to residue is 1:15-1:25, and the inoculation amount of Lactobacillus plantarum is 1.5%-3% of the mass of residue.

[0056] The present invention will be described in detail below through examples and comparative examples, but the scope of protection of the present invention is not limited to these examples. Unless otherwise specified, the chemical reagents and raw materials used in the following examples and comparative examples are all conventional commercially available products.

[0057] Example 1 The volatile oil of clove buds was extracted by steam distillation at 110℃ for 3 hours, and the eugenol fraction and distillation residue were collected. The distillation residue was vacuum dried at 80℃ until the moisture content was no more than 10%, and then pulverized through a 40-mesh sieve to obtain dried clove residue. Hydroxypropyl-β-cyclodextrin was dissolved in deionized water to prepare a saturated aqueous solution, and the eugenol fraction was added dropwise at 55℃ with stirring. The mass ratio of eugenol to hydroxypropyl-β-cyclodextrin was 1:7. The mixture was stirred for 2.5 hours for inclusion, allowed to stand at 4℃ for 16 hours for crystallization, filtered, and vacuum dried at 50℃ to obtain eugenol cyclodextrin inclusion complex powder.

[0058] Angelica root slices were extracted by reflux with 10 times the amount of deionized water for 2 hours, filtered, and the filtrate was concentrated under reduced pressure to a relative density of 1.20 to obtain a concentrate. Pectinase was added at a rate of 5 U per milliliter of concentrate, the pH was adjusted to 4.5, and the mixture was enzymatically hydrolyzed at 55°C for 2.5 hours. The concentrate was then inactivated by boiling in a water bath for 10 minutes. The supernatant was collected by centrifugation, and precipitated with 3 times the volume of anhydrous ethanol. The precipitate was washed 3 times with 95% ethanol, and the supernatant was discarded after each centrifugation. The precipitate was then vacuum dried to obtain Angelica oligosaccharides. The filter residue was vacuum dried at 80°C until the moisture content was no more than 10%, pulverized, and passed through a 40-mesh sieve to obtain the dried Angelica root water extraction residue.

[0059] The dried clove residue and the dried Angelica sinensis root water extract residue were mixed at a mass ratio of 2:1 to obtain the residue. Deionized water was added to prepare a slurry with a mass ratio of residue to deionized water of 1:6. The pH was adjusted to 5.5, and cellulase was added at a dosage of 5 U per gram of residue. The mixture was enzymatically hydrolyzed at 55°C for 3 hours, then heated to 90°C for 15 minutes to inactivate the enzyme. The mixture was cooled to 38°C, and glucose was added at a mass ratio of glucose to residue of 1:15. Lactobacillus plantarum was inoculated at an inoculation amount of 3% of the residue mass. Anaerobic fermentation was carried out at 38°C for 60 hours. The fermentation broth was inactivated by boiling water bath, centrifuged, and the supernatant was collected. The supernatant was concentrated under reduced pressure to a solid content of 15% to obtain the fermented extracellular polysaccharide concentrate.

[0060] Squalane and jojoba oil were mixed at a mass ratio of 2.5:1 and heated to 75°C. Cetearyl alcohol was added, and the mixture was stirred until homogeneous. The resulting product was set aside. Deionized water was heated to 80°C, and cocoyl glucoside, glycerol, and 1,3-propanediol were added. The mass ratio of glycerol to 1,3-propanediol was 3:1, and the mass ratio of deionized water to glycerol was 10:1. The mixture was stirred until dissolved to obtain an aqueous phase, which was also set aside. Under stirring and a temperature of 75°C, the oil phase was slowly added to the aqueous phase. The mixture was then homogenized and circulated three times at a pressure of 20 MPa to obtain an emulsion. The emulsion was then stirred and cooled. When the emulsion temperature dropped to 45°C, angelica oligosaccharide and eugenol cyclodextrin inclusion complex powder were added and stirred until dissolved. The temperature was further lowered to 38°C, and the concentrated fermented extracellular polysaccharide solution was added. The mixture was stirred for 2 hours. Finally, the temperature was lowered to below 35℃, and 1,2-hexanediol and p-hydroxyacetophenone were added in a mass ratio of 0.5:0.3. The mixture was stirred until homogeneous, defoamed, and filled into containers to obtain the ointment. This ointment comprises the following raw materials in parts by weight: 20 parts oil phase, 67.5 parts aqueous phase, 3 parts emulsifier, 2 parts preservative, 3.5 parts eugenol cyclodextrin inclusion complex, 3 parts angelica oligosaccharide, and 8 parts concentrated fermented extracellular polysaccharide broth. The mass ratio of cetearyl alcohol to cocoyl glucoside is 1:1.

[0061] Example 2 In this embodiment, the similarities to those in Embodiment 1 will not be repeated, and the differences are as follows: The volatile oil of clove buds was extracted by steam distillation at 100℃ for 4 hours, and the eugenol fraction and distillation residue were collected. The distillation residue was dried under vacuum at 60℃ until the moisture content was no more than 10%, and then pulverized through a 60-mesh sieve to obtain dried clove residue. Hydroxypropyl-β-cyclodextrin was dissolved in deionized water to prepare a saturated aqueous solution, and the eugenol fraction was added dropwise at 45℃ with stirring. The mass ratio of eugenol to hydroxypropyl-β-cyclodextrin was 1:6. The mixture was stirred for 3 hours to incorporate the eugenol, and then allowed to stand at 4℃ for 12 hours to crystallize. The mixture was filtered and dried under vacuum at 40℃ to obtain a powder of eugenol-cyclodextrin inclusion complex.

[0062] Angelica root slices were extracted by reflux with 8 times the amount of deionized water for 2 hours, filtered, and the filtrate was concentrated under reduced pressure to a relative density of 1.10 to obtain a concentrate. Pectinase was added at a dosage of 7.5 U per milliliter of concentrate, the pH was adjusted to 4.0, and enzymatic hydrolysis was carried out at 50°C for 3 hours. The concentrate was then inactivated by boiling water bath for 10 minutes. The supernatant was collected by centrifugation, and precipitated with 3 times the volume of anhydrous ethanol. The precipitate was washed twice with 85% ethanol, and the supernatant was discarded after each centrifugation. The precipitate was vacuum dried to obtain Angelica oligosaccharides. The filter residue was vacuum dried at 60°C until the moisture content was no more than 10%, pulverized and passed through a 60-mesh sieve to obtain the dried Angelica root water extraction residue.

[0063] The dried clove residue and the dried Angelica sinensis root water extract residue were mixed at a mass ratio of 1:1 to obtain the residue. Deionized water was added to prepare a slurry with a mass ratio of residue to deionized water of 1:10. The pH was adjusted to 4.5, and cellulase was added at a dosage of 10U per gram of residue. The mixture was enzymatically hydrolyzed at 45°C for 4 hours, then heated to 80°C for 15 minutes to inactivate the enzyme. The mixture was cooled to 35°C, and glucose was added at a mass ratio of glucose to residue of 1:20. Lactobacillus plantarum was inoculated at an inoculation amount of 1.5% of the residue mass. Anaerobic fermentation was carried out at 35°C for 72 hours. The fermentation broth was inactivated by boiling water bath, centrifuged, and the supernatant was collected. The supernatant was concentrated under reduced pressure to a solid content of 8% to obtain the fermented extracellular polysaccharide concentrate.

[0064] Squalane and jojoba oil were mixed at a mass ratio of 3:1 and heated to 70°C. Cetearyl alcohol was added, and the mixture was stirred until homogeneous. The resulting product was set aside. Deionized water was heated to 75°C, and cocoyl glucoside, glycerol, and 1,3-propanediol were added. The mass ratio of glycerol to 1,3-propanediol was 2:1, and the mass ratio of deionized water to glycerol was 10:1. The mixture was stirred until dissolved to obtain an aqueous phase, which was also set aside. Under stirring and a temperature of 70°C, the oil phase was slowly added to the aqueous phase. The mixture was then homogenized and circulated twice at a pressure of 25 MPa to obtain an emulsion. The emulsion was then stirred and cooled. When the emulsion temperature dropped to 40°C, angelica oligosaccharide and eugenol cyclodextrin inclusion complex powder were added and stirred until dissolved. The temperature was further lowered to 35°C, and the concentrated fermented extracellular polysaccharide solution was added. The mixture was stirred for 1 hour. Finally, the temperature was lowered to below 35℃, and 1,2-hexanediol and p-hydroxyacetophenone were added in a mass ratio of 1.0:0.5. The mixture was stirred until homogeneous, defoamed, and filled into containers to obtain the ointment. This ointment comprises the following raw materials in parts by weight: 15 parts oil phase, 75 parts aqueous phase, 5.5 parts emulsifier, 0.5 parts preservative, 5 parts eugenol cyclodextrin inclusion complex, 4.5 parts angelica oligosaccharide, and 4 parts concentrated fermented extracellular polysaccharide broth. The mass ratio of cetearyl alcohol to cocoyl glucoside is 1:2.

[0065] Example 3 In this embodiment, the similarities to those in Embodiment 1 will not be repeated, and the differences are as follows: The volatile oil of clove buds was extracted by steam distillation at 105℃ for 2 hours, and the eugenol fraction and distillation residue were collected. The distillation residue was vacuum dried at 70℃ until the moisture content was no more than 10%, and then pulverized through a 50-mesh sieve to obtain dried clove residue. Hydroxypropyl-β-cyclodextrin was dissolved in deionized water to prepare a saturated aqueous solution, and the eugenol fraction was added dropwise with stirring at 50℃. The mass ratio of eugenol to hydroxypropyl-β-cyclodextrin was 1:7. The mixture was stirred for 2 hours to encapsulate the inclusion complex, and then allowed to stand at 4℃ for 14 hours to crystallize. The mixture was then filtered and vacuum dried at 45℃ to obtain a powder of eugenol-cyclodextrin inclusion complex.

[0066] Angelica root slices were extracted by reflux with 9 times the amount of deionized water for 2 hours, filtered, and the filtrate was concentrated under reduced pressure to a relative density of 1.15 to obtain a concentrate. Pectinase was added at a rate of 10 U per milliliter of concentrate, the pH was adjusted to 4.2, and the mixture was enzymatically hydrolyzed at 52°C for 2 hours. The concentrate was then inactivated by boiling in a water bath for 10 minutes. The supernatant was collected by centrifugation, and 3 times the volume of anhydrous ethanol was added for precipitation. The precipitate was washed twice with 90% ethanol, and the supernatant was discarded after each centrifugation. The precipitate was then vacuum dried to obtain Angelica oligosaccharides. The filter residue was vacuum dried at 70°C until the moisture content was no more than 10%, and then pulverized through a 50-mesh sieve to obtain the dried Angelica root water extraction residue.

[0067] The dried clove residue and the dried Angelica sinensis root water extract residue were mixed at a mass ratio of 2:1 to obtain the residue. Deionized water was added to prepare a slurry with a mass ratio of residue to deionized water of 1:8. The pH was adjusted to 5.0, and cellulase was added at a dosage of 15 U per gram of residue. The mixture was enzymatically hydrolyzed at 50°C for 2 hours, then heated to 85°C for 12 minutes to inactivate the enzyme. The mixture was cooled to 36°C, and glucose was added at a mass ratio of glucose to residue of 1:25. Lactobacillus plantarum was inoculated at an inoculation amount of 2.25% of the residue mass. Anaerobic fermentation was carried out at 36°C for 48 hours. The fermentation broth was inactivated by boiling water bath, centrifuged, and the supernatant was collected. The supernatant was concentrated under reduced pressure to a solid content of 12% to obtain the fermented extracellular polysaccharide concentrate.

[0068] Squalane and jojoba oil were mixed at a mass ratio of 2:1 and heated to 72°C. Cetearyl alcohol was added, and the mixture was stirred until homogeneous. The resulting product was set aside. Deionized water was heated to 78°C, and cocoyl glucoside, glycerol, and 1,3-propanediol were added. The mass ratio of glycerol to 1,3-propanediol was 3:1, and the mass ratio of deionized water to glycerol was 12.5:1. The mixture was stirred until dissolved to obtain an aqueous phase. The resulting product was set aside. Under stirring and a temperature of 72°C, the oil phase was slowly added to the aqueous phase while stirring. The mixture was then homogenized and circulated three times under a pressure of 30 MPa to obtain an emulsion. The emulsion was then stirred and cooled. When the emulsion temperature dropped to 42°C, angelica oligosaccharide and eugenol cyclodextrin inclusion complex powder were added and stirred until dissolved. The temperature was further lowered to 36°C, and the concentrated fermented extracellular polysaccharide solution was added. The mixture was stirred for 1.5 hours. Finally, the temperature was lowered to below 35℃, and 1,2-hexanediol and p-hydroxyacetophenone were added in a mass ratio of 0.75:0.4. The mixture was stirred until homogeneous, defoamed, and filled into containers to obtain the ointment. This ointment comprises the following raw materials in parts by weight: 17.5 parts oil phase, 60 parts aqueous phase, 8 parts emulsifier, 1.25 parts preservative, 2 parts eugenol cyclodextrin inclusion complex, 6 parts angelica oligosaccharide, and 6 parts fermented extracellular polysaccharide concentrate. The mass ratio of cetearyl alcohol to cocoyl glucoside is 1:1.

[0069] Example 4 In this embodiment, the similarities to those in Embodiment 1 will not be repeated, and the differences are as follows: The volatile oil of clove buds was extracted by steam distillation at 105℃ for 3 hours, and the eugenol fraction and distillation residue were collected. The distillation residue was vacuum dried at 70℃ until the moisture content was no more than 10%, and then pulverized through a 50-mesh sieve to obtain dried clove residue. Hydroxypropyl-β-cyclodextrin was dissolved in deionized water to prepare a saturated aqueous solution, and the eugenol fraction was added dropwise with stirring at 50℃. The mass ratio of eugenol to hydroxypropyl-β-cyclodextrin was 1:6. The mixture was stirred for 2.5 hours for inclusion, allowed to stand at 4℃ for 14 hours for crystallization, filtered, and vacuum dried at 45℃ to obtain eugenol cyclodextrin inclusion complex powder.

[0070] Angelica root slices were extracted by reflux with 9 times the amount of deionized water for 2 hours, filtered, and the filtrate was concentrated under reduced pressure to a relative density of 1.15 to obtain a concentrate. Pectinase was added at a rate of 8 U per milliliter of concentrate, the pH was adjusted to 4.2, and the mixture was enzymatically hydrolyzed at 52°C for 2.5 hours. The concentrate was then inactivated by boiling in a water bath for 10 minutes. The supernatant was collected by centrifugation, and 3 times the volume of anhydrous ethanol was added for precipitation. The precipitate was washed twice with 90% ethanol, and the supernatant was discarded after each centrifugation. The precipitate was then vacuum dried to obtain Angelica oligosaccharides. The filter residue was vacuum dried at 70°C until the moisture content was no more than 10%, and then pulverized through a 50-mesh sieve to obtain the dried Angelica root water extraction residue.

[0071] The dried clove residue and the dried Angelica sinensis root water extract residue were mixed at a mass ratio of 1.5:1 to obtain the residue. Deionized water was added to prepare a slurry with a mass ratio of residue to deionized water of 1:8. The pH was adjusted to 5.0, and cellulase was added at a dosage of 12U per gram of residue. The mixture was enzymatically hydrolyzed at 50°C for 3 hours, then heated to 85°C for 12 minutes to inactivate the enzyme. The mixture was cooled to 36°C, and glucose was added at a mass ratio of glucose to residue of 1:20. Lactobacillus plantarum was inoculated at an inoculation amount of 2.5% of the residue mass. Anaerobic fermentation was carried out at 36°C for 60 hours. The fermentation broth was inactivated by boiling water bath, centrifuged, and the supernatant was collected. The supernatant was concentrated under reduced pressure to a solid content of 12% to obtain the fermented extracellular polysaccharide concentrate.

[0072] Squalane and jojoba oil were mixed at a mass ratio of 2.5:1 and heated to 72°C. Cetearyl alcohol was added, and the mixture was stirred until homogeneous. The resulting product was set aside. Deionized water was heated to 78°C, and cocoyl glucoside, glycerol, and 1,3-propanediol were added. The mass ratio of glycerol to 1,3-propanediol was 2.5:1, and the mass ratio of deionized water to glycerol was 12:1. The mixture was stirred until dissolved to obtain an aqueous phase. The resulting product was set aside. Under stirring and a temperature of 72°C, the oil phase was slowly added to the aqueous phase while stirring. The mixture was then homogenized and circulated twice under a pressure of 25 MPa to obtain an emulsion. The emulsion was then stirred and cooled. When the emulsion temperature dropped to 42°C, angelica oligosaccharide and eugenol cyclodextrin inclusion complex powder were added and stirred until dissolved. The temperature was further lowered to 36°C, and the concentrated fermented extracellular polysaccharide solution was added. The mixture was stirred for 1.5 hours. Finally, the temperature was lowered to below 35℃, and 1,2-hexanediol and p-hydroxyacetophenone were added in a mass ratio of 0.75:0.4. The mixture was stirred until homogeneous, defoamed, and filled into containers to obtain the ointment. This ointment comprises the following raw materials in parts by weight: 18 parts oil phase, 70 parts aqueous phase, 6 parts emulsifier, 1.2 parts preservative, 4 parts eugenol cyclodextrin inclusion complex, 5 parts angelica oligosaccharide, and 7 parts concentrated fermented extracellular polysaccharide broth. The mass ratio of cetearyl alcohol to cocoyl glucoside is 1:1.5.

[0073] Comparative Example 1 Compared with Example 1, the second step does not use hydroxypropyl-β-cyclodextrin inclusion, and the eugenol fraction is directly added to the aqueous phase in a free state. The other steps and parameters are exactly the same as in Example 1.

[0074] Comparative Example 2 Compared with Example 2, in the third step, pectinase hydrolysis is not used. Instead, the concentrated aqueous extract of Angelica sinensis root is directly vacuum-dried to obtain macromolecular Angelica sinensis polysaccharide. The other steps and parameters are exactly the same as in Example 2.

[0075] Comparative Example 3 Compared with Example 3, in the fourth step, Lactobacillus plantarum fermentation is not used. Carbomer is used directly instead of the fermented extracellular polysaccharide concentrate as a thickener. The amount of carbomer used is 0.8% of the total mass of the ointment. Other steps and parameters are exactly the same as in Example 3.

[0076] Comparative Example 4 Compared with Example 4, the step-by-step cooling process is not used in the seventh step. Instead, all aqueous phase components, including Angelica oligosaccharide, eugenol cyclodextrin inclusion complex powder, fermentation extracellular polysaccharide concentrate, 1,2-hexanediol and p-hydroxyacetophenone, are added at 72°C all at once. The other steps and parameters are exactly the same as in Example 4.

[0077] Performance Test Results and Analysis The ointment samples prepared according to the parameters of the examples and comparative examples were tested according to the following methods.

[0078] The chorioallantoic membrane test was used to evaluate skin irritation. 0.3 g of each of the ointment samples prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were evenly applied to the surface of the chorioallantoic membrane of white Lehening chicken embryos hatched for 9 days. Six replicates were set for each sample. Vascular changes were observed continuously for 5 minutes after application, and bleeding, hemolysis, and clotting times were recorded. Irritation scores were recorded according to a standardized scoring system, ranging from 0 to 5, with higher scores indicating stronger irritation.

[0079] Skin moisture content was determined using a Corneometer CM825. The flexor surface of the forearm was selected as the test site. Before the test, subjects sat quietly for 30 minutes in a constant temperature and humidity environment (25±1℃, 50±5% relative humidity). The baseline skin moisture content was measured using a Corneometer CM825 probe before applying each sample and recorded as the baseline value. Subsequently, 0.05g of each sample was evenly applied to a 3cm×3cm marked area. Measurements were taken at 1h, 2h, 4h, and 8h after application, with three measurements taken at each time point. The average value was used, and the measurement at 8h after application was used as the final skin moisture content value for inter-group comparison.

[0080] The Tewameter™ 300 was used to determine transdermal water loss (TEWL). The testing conditions were the same as described above. The baseline TEWL value was measured using the Tewameter™ 300 probe before application to each sample and recorded as the baseline. After sample application, TEWL values ​​were measured in the marked areas at 1h, 2h, 4h, and 8h. Measurements were taken three times at each time point, and the average value was used. The measurement at 8h post-application was taken as the final TEWL value. A lower TEWL value indicates better skin barrier function and less water loss.

[0081] The abrasion resistance was evaluated using the standard gauze wiping method after application. 0.2g of each sample was evenly applied to the surface of a 3cm × 3cm polymethyl methacrylate (PMMA) standard substrate, which had been pre-treated with simulated skin fluid. After application, the substrate was allowed to stand for 15 minutes to form a film. Then, it was wiped with standard gauze at a constant pressure of 5N and a reciprocating speed of 10cm / s, repeated 10 times. The mass of residual paste was weighed using a precision balance after wiping, and the residue rate was calculated as the residual mass divided by the initial application mass and then multiplied by 100%. Five replicates were performed for each sample.

[0082] The cumulative release of eugenol was determined using the Franz diffusion cell method. A vertical Franz diffusion cell with an effective diffusion area of ​​1.77 cm² was used. The receiving cell volume was 7 mL, and the receiving solution was phosphate buffer containing 30% ethanol at pH 7.4. The temperature was maintained at 32 ± 0.5 °C. 0.3 g of each of the ointment samples from Examples 1 to 4 and Comparative Examples 1 to 4 were uniformly applied to the surface of pre-hydrated pig ear skin keratinocytes and fixed between the supply and receiving cells. 1 mL samples were taken from the receiving cell at 1 h, 2 h, 4 h, 6 h, and 8 h, and isothermal fresh receiving solution was added. The eugenol content in the samples was determined using high-performance liquid chromatography (HPLC) with a C18 column, a methanol-water mobile phase, and a detection wavelength of 280 nm. The cumulative release at 8 h was calculated, representing the percentage of total eugenol mass in the receiving cell relative to the total eugenol mass in the supply cell at 8 h.

[0083] Oxidative stability was evaluated by measuring the total color difference value ΔE using a colorimeter. 10g of each sample was placed in separate transparent glass bottles, sealed, and stored at 45℃ for 30 days. After storage, the total color difference value ΔE of the ointment samples was measured using a colorimeter. A freshly prepared corresponding sample was used as a reference, and the values ​​of L, a, and b were measured. The total color difference value ΔE was calculated using the formula: ΔE equals the square root of the sum of the squares of the differences in L, a, and b. A larger color difference value indicates more severe oxidative discoloration.

[0084] Centrifugation acceleration test was used to evaluate the stability of the ointment. 10g of each sample was placed in a centrifuge tube and centrifuged at 4000 rpm for 30 minutes. The presence of stratification, oil separation, or precipitation was observed. The stratification rate was recorded as the volume of the separated aqueous or oil phase divided by the total volume of the ointment, then multiplied by 100%.

[0085] The test results are shown in Table 1 and... Figure 2 As shown.

[0086] Table 1 shows the performance test results. From the skin irritation scores in Table 1, Examples 1 to 4 all maintained low levels, which is attributed to the formation of the eugenol cyclodextrin inclusion complex. Hydroxypropyl-β-cyclodextrin is truncated conical in shape, with a hydrophobic microenvironment inside the cavity. After the benzene ring structure of eugenol is embedded in this cavity, it is stably bound through van der Waals forces and hydrophobic interactions, preventing the phenolic hydroxyl groups from being directly exposed to the skin surface, thus reducing irritation. In Comparative Example 1, eugenol exists in a free state, and its phenolic hydroxyl groups can directly interact with skin proteins, resulting in a significantly higher irritation score, confirming the necessity of inclusion treatment. Although Comparative Examples 2 and 3 did not involve inclusion processing, the uneven distribution of active ingredients due to differences in the ointment matrix led to higher local concentrations, resulting in higher irritation scores than the Examples. In Comparative Example 4, the one-time addition at high temperature destroyed part of the inclusion complex structure, causing a small amount of eugenol to be released freely, resulting in an irritation score slightly higher than the Examples but lower than Comparative Example 1.

[0087] Table 1 Example 1 0.8 85 8.5 0 Example 2 0.6 82 9.0 0 Example 3 0.7 80 9.2 0 Example 4 0.5 88 7.8 0 Comparative Example 1 2.5 78 10.5 2 Comparative Example 2 1.0 70 12.0 5 Comparative Example 3 1.2 72 11.5 0 Comparative Example 4 1.0 75 10.0 8 Table 1 shows the test results of skin moisture content and transepidermal water loss (TEWL) values. The moisture content of the examples was higher than that of the comparative examples, while the TEWL values ​​were lower. In the examples, the molecular weight of Angelica oligosaccharides decreased, allowing them to penetrate the superficial stratum corneum. The hydroxyl groups retained on their chains formed hydrogen bonds with the amino and carbonyl groups of keratin, constructing a hydration layer and improving the skin's own water retention capacity. Simultaneously, the fermented extracellular polysaccharides formed a bioadhesive membrane on the skin surface, reducing water evaporation. In Comparative Example 2, the Angelica polysaccharides were not enzymatically hydrolyzed, and the large molecules could not penetrate the stratum corneum, only forming a temporary moisturizing layer on the surface, resulting in poor moisture content and TEWL performance. Comparative Example 3 used carbomer as a thickener; although the paste had high viscosity, it lacked specific interaction with skin keratin, making it difficult to form a continuous adhesion film on the damaged skin surface, leading to rapid water loss. In Comparative Example 4, high temperature disrupted the self-assembly of the tertiary polysaccharide network, resulting in insufficient hydrogen bond cross-linking, a loose membrane structure, and a decreased water retention effect.

[0088] Figure 2 The graph shows the test results for abrasion resistance, cumulative eugenol release, and oxidative stability. Figure 2 -A represents the result of the abrasion resistance test. Figure 2 -B represents the cumulative release result of eugenol. Figure 2 -C represents the result of the oxidation stability test.

[0089] from Figure 2 The abrasion resistance test results reflect the adhesion ability of the ointment to the skin surface. In the examples, the hydroxyl and carboxyl groups on the long chains of fermented extracellular polysaccharides form multiple hydrogen bonds with skin keratin, generating mild bioadhesive force, allowing the ointment to retain a high level of residue after wiping. In Comparative Example 3, carbomer is thickened through physical entanglement of polymer chains, and its adhesion to the skin is only mechanical. It is easily detached in whole pieces when wiped by external force, resulting in a low residue rate. In Comparative Example 4, due to the addition of all components at high temperature at one time, the tertiary polysaccharide network failed to achieve self-assembly through stepwise cooling, resulting in insufficient hydrogen bond cross-linking, a loose network structure, and a significant decrease in abrasion resistance. Although Comparative Examples 1 and 2 contain fermented extracellular polysaccharides, the network density is insufficient due to the compatibility of active ingredients or molecular weight issues, and the abrasion resistance is also lower than that of the examples.

[0090] The cumulative release of eugenol tested showed that the release amount in the example was lower than that in Comparative Example 1 within 8 hours, indicating that the inclusion complex achieved a sustained-release effect. The cavity of hydroxypropyl-β-cyclodextrin physically binds eugenol, and the gradual dissociation driven by the moisture gradient slows down the release rate. In Comparative Example 1, free eugenol is not bound by a carrier, resulting in low diffusion resistance and rapid release. Large-scale release in a short period not only leads to waste but may also exacerbate irritation. In Comparative Example 4, due to the high temperature damaging part of the inclusion complex structure and the failure of the tertiary network to effectively anchor, the release amount was significantly higher than that in the example, weakening the sustained-release effect. Comparative Examples 2 and 3 showed lower release amounts, but this is not effective sustained release. Rather, it is because the dense structure of the macromolecular polysaccharide or carbomer hinders the release of the active ingredient, preventing it from effectively penetrating to the site of action. This is incomplete release rather than controlled sustained release.

[0091] Oxidative stability testing reflects the degree of discoloration during ointment storage through color difference values. In the examples, eugenol was encapsulated by the cyclodextrin cavity, isolating it from oxygen and reducing its oxidative degradation rate. In Comparative Example 1, free eugenol was directly exposed to the oxygen-containing environment of the ointment, and the phenolic hydroxyl groups were easily oxidized into quinone-based colored substances, resulting in a significant increase in color difference values. Although Comparative Examples 2, 3, and 4 did not completely remove the inclusion complex, process defects led to decreased ointment stability, and the network structure provided insufficient protection for the active ingredient, indirectly accelerating the oxidation of eugenol; their color difference values ​​were all higher than those of the examples.

[0092] Centrifugal stability tests evaluated the physical stability of the ointment, as shown in Table 1. In the examples, no stratification occurred under accelerated centrifugation, indicating the stability of the liquid crystal emulsion system and the tertiary polysaccharide network structure. In Comparative Example 2, the un-enzymatically hydrolyzed Angelica polysaccharide had a large molecular weight and poor compatibility with the matrix, easily separating from the system during centrifugation, resulting in a higher stratification rate. In Comparative Example 4, the one-time addition at high temperature disrupted the liquid crystal structure formed by the emulsifier at the oil-water interface, leading to oil droplet aggregation and the highest stratification rate. In Comparative Example 1, the interaction between free eugenol and the oil altered the interfacial properties, also causing slight stratification. Comparative Example 3 used carbomer thickener, which itself has good suspension stability and a centrifugal stratification rate of 0, but its defects in skin adhesion and active ingredient release were reflected by other indicators.

[0093] This application reduces eugenol irritation and prolongs retention through cyclodextrin inclusion, enhances transdermal permeability through enzymatic hydrolysis of Angelica polysaccharides, and uses fermentation residue to replace synthetic thickeners to form a bioadhesive membrane. The three components are cross-linked by hydrogen bonds to construct a three-level polysaccharide network, achieving a synergistic improvement in soothing, moisturizing and retention.

[0094] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A skin-residual ointment with soothing, repairing, moisturizing, and skin-nourishing properties, characterized in that, The ointment comprises the following raw materials in parts by weight: 15-20 parts oil phase, 60-75 parts aqueous phase, 3-8 parts emulsifier, 0.5-2 parts preservative, 2-5 parts eugenol cyclodextrin inclusion complex, 3-6 parts angelica oligosaccharide, and 4-8 parts fermented extracellular polysaccharide concentrate.

2. The skin-residual ointment with soothing, repairing, moisturizing and skin-nourishing effects according to claim 1, characterized in that, The oil phase comprises squalane and jojoba oil, wherein the mass ratio of squalane to jojoba oil is 2-3:

1.

3. A skin-residual ointment with soothing, repairing, moisturizing, and skin-nourishing properties according to claim 1, characterized in that, The aqueous phase comprises deionized water, glycerol, and 1,3-propanediol, wherein the mass ratio of glycerol to 1,3-propanediol is 2-3:1; and the mass ratio of deionized water to glycerol is 10-15:

1.

4. A skin-residual ointment with soothing, repairing, moisturizing, and skin-nourishing properties according to claim 1, characterized in that, The emulsifier comprises cetearyl alcohol and cocoyl glucoside, wherein the mass ratio of cetearyl alcohol to cocoyl glucoside is 1:1 to 1:

2.

5. A skin-residual ointment with soothing, repairing, moisturizing, and skin-nourishing properties according to claim 1, characterized in that, The preservative comprises 1,2-hexanediol and p-hydroxyacetophenone, wherein the mass ratio of 1,2-hexanediol to p-hydroxyacetophenone is 0.5-1.0:0.3-0.

5.

6. A method for preparing a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties as described in claim 1, characterized in that, The method includes the following steps: Step 1: Extract volatile oil from clove buds by steam distillation, collect eugenol fraction and distillation residue, and use the distillation residue to prepare dried clove residue; Step 2: Dissolve hydroxypropyl-β-cyclodextrin in deionized water to prepare a saturated aqueous solution, and add the eugenol fraction collected in step 1 dropwise under stirring at 45-55℃ to obtain eugenol cyclodextrin inclusion complex powder. The third step is to prepare Angelica oligosaccharides by slicing Angelica root and prepare Angelica root water extraction residue from the filter residue. Step 4: Mix the dried clove residue obtained in Step 1 with the dried Angelica root water extract residue obtained in Step 3 to prepare a fermented extracellular polysaccharide concentrate. Step 5: Mix squalane and jojoba oil and heat to 70-75°C. Add cetearyl alcohol and stir until melted and homogeneous. Set the product aside. Step 6: Heat deionized water to 75-80℃, add cocoyl glucoside, glycerol, and 1,3-propanediol, stir to dissolve and obtain an aqueous phase. The resulting product is ready for use. Step 7: Under stirring and maintaining a temperature of 70-75℃, slowly add the product obtained in Step 5 to the product obtained in Step 6 while stirring. Then, homogenize and circulate the mixture 2-3 times under a pressure of 20-30MPa to obtain an emulsion. Then, stir and cool down. When the emulsion temperature drops to 40-45℃, add the Angelica oligosaccharide obtained in Step 3 and the eugenol cyclodextrin inclusion complex powder obtained in Step 2, and stir to dissolve. Continue to cool down to 35-38℃ and add the fermented extracellular polysaccharide concentrate obtained in Step 4, and stir for 1-2 hours. Finally, cool down to below 35℃, add 1,2-hexanediol and p-hydroxyacetophenone, stir evenly, defoam, and fill into containers to obtain a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties.

7. The method for preparing a skin-retaining ointment with soothing, repairing, moisturizing and skin-nourishing properties according to claim 6, characterized in that, In the first step, the specific parameters for steam distillation are: distillation temperature 100-110℃, time 2-4h; The steps for preparing dried clove residue from the distillation residue include: vacuum drying the distillation residue at 60-80℃ until the moisture content is not higher than 10%, and pulverizing it through a 40-60 mesh sieve to obtain dried clove residue.

8. The method for preparing a skin-retaining ointment with soothing, repairing, moisturizing and skin-nourishing properties according to claim 6, characterized in that, In the second step, the mass ratio of eugenol to hydroxypropyl-β-cyclodextrin is 1:5-1:7; The specific parameters for the inclusion treatment are: stirring and inclusion for 2-3 hours, standing crystallization at 4°C for 12-16 hours, filtration, and vacuum drying at 40-50°C.

9. The method for preparing a skin-retaining ointment with soothing, repairing, moisturizing and skin-nourishing properties according to claim 6, characterized in that, In the third step, the preparation of Angelica oligosaccharides and Angelica root water extract residue includes the following steps: Angelica root slices are added, 8-10 times the amount of deionized water is added and refluxed for 2 hours, filtered, and the filtrate is concentrated under reduced pressure to a relative density of 1.10-1.20 to obtain a concentrated solution. Pectinase is added, the pH is adjusted to 4.0-4.5, and enzymatic hydrolysis is carried out at 50-55℃ for 2-3 hours. The solution is then inactivated in a boiling water bath for 10 minutes, centrifuged to obtain the supernatant, and 3 times the volume of anhydrous ethanol is added for alcohol precipitation. The precipitate is washed 2-3 times with 85%-95% ethanol, and the supernatant is discarded after each centrifugation. The solution is then vacuum dried to obtain Angelica oligosaccharides. The filter residue is vacuum dried at 60-80℃ until the moisture content is not higher than 10%, and then pulverized through a 40-60 mesh sieve to obtain dried Angelica root water extract residue. The amount of pectinase used is 5-10 U per milliliter of concentrate.

10. A method for preparing a skin-retaining ointment with soothing, repairing, moisturizing, and skin-nourishing properties according to claim 6, characterized in that, In the fourth step, the preparation of the fermented extracellular polysaccharide concentrate includes the following steps: the dried clove residue obtained in the first step and the dried angelica root water extract residue obtained in the third step are mixed at a mass ratio of 1:1-2:1 to obtain residue, deionized water is added to prepare a slurry, the mass ratio of the residue to deionized water is 1:6-1:10, the pH is adjusted to 4.5-5.5, cellulase is added, enzymatic hydrolysis is carried out at 45-55℃ for 2-4 hours, the temperature is raised to 80-90℃ for 10-15 minutes to inactivate, the temperature is cooled to 35-38℃, glucose is added, Lactobacillus plantarum is inoculated, and anaerobic fermentation is carried out at 35-38℃ for 48-72 hours. The fermentation broth is inactivated by boiling water bath, centrifuged to obtain the supernatant, and concentrated under reduced pressure to a solid content of 8%-15% to obtain the fermented extracellular polysaccharide concentrate. The amount of cellulase used is 5-15 U per gram of residue, the mass ratio of glucose to residue is 1:15-1:25, and the inoculation amount of Lactobacillus plantarum is 1.5%-3% of the mass of residue.

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