Lipstick for preventing and treating chapped lips and preparation process thereof

Abstract

The invention discloses a lipstick for preventing and treating chapped lips and a preparation process thereof, and belongs to the technical field of cosmetics. According to the composition, an active matter is encapsulated in a core layer of nanofibers, pullulan and chitosan serve as a shell layer, the chemical characteristics of the shell layer are utilized in the design, basic slow release of moisture response and targeted release of enzyme response are achieved, and therefore the lip is repaired precisely in a long-acting mode; meanwhile, by utilizing the physical characteristics of the shell layer and designing the glass-transition temperature of the shell layer to be close to the body temperature, the fiber is endowed with temperature-sensitive self-plasticizing capability and softened after entering the lips, and excellent smooth skin feeling and optical soft focus effect are brought. The composition is prepared through key processes such as coaxial electrostatic spinning, low-temperature superfine grinding and low-temperature dispersion homogenization. The technical problems that in the prior art, active matter is out of control in release, easy to degrade, poor in makeup keeping performance and poor in skin feeling are solved, and the efficacy, stability and use experience of the product are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and in particular to a lipstick for preventing and treating chapped lips and its preparation process. Background Technology

[0002] The skin around the lips has a unique structure, with an extremely thin stratum corneum and a lack of sebaceous glands. Therefore, it is highly susceptible to dryness, peeling, and cracking due to factors such as dryness, wind, or poor hygiene. To prevent and improve these conditions, various moisturizing and repairing lip care products, such as lip balms and functional lipsticks, are available on the market. These products typically achieve their claimed effects by simply physically mixing various moisturizers, plant extracts, or bioactive ingredients into a wax- and oil-based base.

[0003] However, the current technology, which commonly employs direct mixing and addition, has some inherent flaws that are difficult to overcome. The core problem lies in the lack of an effective mechanism to regulate the action of active ingredients. When the product is applied to the lips, the active ingredients, simply dispersed in the matrix, tend to be released rapidly and indiscriminately, creating a short-lived "burst effect." This makes it difficult to achieve continuous, long-lasting nourishment and repair for the lip skin, requiring frequent reapplication to maintain the effect. Furthermore, this release method lacks intelligence, failing to concentrate the key repairing ingredients on the dry, cracked areas where they are most needed, resulting in a waste of active ingredients and reducing the overall efficacy of the product.

[0004] Furthermore, many highly effective bioactive ingredients (such as specific plant extracts or biomimetic lipids) are highly sensitive to environmental factors such as heat, light, and oxygen. The traditional manufacturing process of lipsticks or lip balms inevitably involves melting the oil-wax matrix at high temperatures, a process that easily leads to the degradation or inactivation of these precious and fragile active ingredients, significantly reducing the actual efficacy of the final product. Even if the active ingredients survive the manufacturing process, their exposed state within the product matrix presents ongoing stability challenges during storage and use.

[0005] Finally, while existing products offer functionality, they often struggle to provide a superior user experience. The feel on the skin during application and the staying power are largely determined by the ratio of oil-wax bases. Sometimes, certain functional powders added to enhance efficacy can actually create a grainy or heavy feeling. Furthermore, the product's adhesion to the lips is limited, making it prone to flaking off during daily activities such as eating and talking, further shortening its already limited effective time and hindering the full realization of its claimed benefits. Summary of the Invention

[0006] This invention aims to solve the technical problems of existing functional lipsticks, which suffer from uncontrolled release of active ingredients, easy degradation, and difficulty in long-term adhesion to the lips due to the direct addition of active ingredients, resulting in poor overall repair effect.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: The first aspect of this invention provides a lipstick for preventing and treating chapped lips.

[0008] The lipstick comprises a matrix and functional nanofiber powder uniformly distributed in the matrix.

[0009] The functional nanofiber powder is composed of nanofibers with a core-shell structure. This core-shell structure provides physical isolation for the internal active ingredients, improving their stability in the matrix.

[0010] The shell of the nanofibers is composed of a biocompatible chitosan and pullulan composite. The design of this shell material has two core features: Firstly, it possesses a release mechanism with a dual response of water and enzymes. The pullulan polysaccharide portion swells slowly upon contact with water in saliva, achieving a basic and continuous release of the active ingredient; the chitosan portion can be specifically degraded by lysozyme accumulated in inflamed or damaged areas of the lips, thereby achieving targeted and accelerated release of the active ingredient in that area.

[0011] Secondly, the glass transition temperature of the shell material. The temperature is precisely controlled within the range of 30°C to 35°C. This design endows the nanofibers with temperature-sensitive self-plasticizing physical properties. At room temperature, the fibers are in a firm, glassy state, making them easy to process and disperse; when applied to lips with body temperature, the temperature rises beyond that range. The fibrous shell then transforms into a soft, rubbery state. This physical transformation results in an extremely smooth and comfortable feel against the skin, and by altering the microscopic morphology of the fiber surface, it diffuses light, thereby visually blurring lip lines and creating a soft-focus effect.

[0012] The core layer of the nanofiber carries active ingredients for preventing or treating chapped lips.

[0013] In a preferred embodiment, the active ingredients in the core layer include shikonin, glycyrrhetinic acid, and a biomimetic sebum repair agent composed of ceramides, phytosphingosine, and sea buckthorn fruit oil. This combination of components provides multiple benefits, including anti-inflammatory effects, promoting healing, and repairing the lip's lipid barrier.

[0014] In a preferred embodiment, to achieve the aforementioned precise glass transition temperature and dual-response function, the dry weight ratio of pullulan to chitosan in the shell is 3:1 to 5:1.

[0015] To meet the homogeneity requirements of lipstick, the functional nanofiber powder is composed of short-cut nanofibers with a length of 50 to 100 micrometers.

[0016] In a preferred embodiment, the lipstick comprises, by weight parts: Functional nanofiber powder: 2-5 parts; Wax component: 15-25 parts, which may be selected from at least one of candelilla wax, beeswax, and carnauba wax; Oil components: 50-70 parts, which may be selected from at least one of jojoba seed oil, shea butter, and meadowfoam seed oil; functional additives: 1-2 parts.

[0017] A second aspect of the present invention provides a preparation process for the lipstick for preventing and treating chapped lips.

[0018] The innovation of this process lies in the fact that it achieves the preparation of the aforementioned nanomaterials with precise structures and temperature-sensitive properties through a specific combination of processes, and ensures the integrity of their functions in the final product.

[0019] The preparation process includes the following steps: Step a involves using coaxial electrospinning technology to spin a core-shell nanofiber mat containing the active ingredient and a shell-shell fluid containing chitosan and pullulan. This step is crucial for constructing the core structure of the functional carrier. By simultaneously stretching the two fluids under an electric field, precise encapsulation of the active ingredient is achieved in a one-step process.

[0020] In a preferred embodiment, step (a) specifically includes: first, preparing a W / O type emulsion of active ingredients such as shikonin and glycyrrhetinic acid as the core fluid; then dissolving chitosan and pullulan in a predetermined ratio as the shell fluid. In a preferred embodiment, to ensure the morphology and structural integrity of the nanofibers, the process parameters of step (a) are: voltage 15-25kV, receiving distance 15-20cm, core fluid flow rate 0.1-0.3mL / h, and shell fluid flow rate 0.8-1.5mL / h.

[0021] Step b involves low-temperature ultrafine pulverization of the core-shell structured nanofiber felt to obtain functional nanofiber powder. This step solves the technical challenge of incompatibility between the macroscopic products of electrospinning and the microscopic dispersion system of lipstick.

[0022] In a preferred embodiment, the step specifically involves immersing the nanofiber felt in liquid nitrogen for deep freezing to harden and embrittle it, and then using mechanical force to pulverize it into short-cut powder with a length of 50 to 100 micrometers. This process completely preserves the core-shell structure of the fiber.

[0023] Step c involves dispersing the functional nanofiber powder in a molten lipstick matrix at a temperature of 55–60°C, followed by homogenization, filling, and cooling before shaping. This step employs a significantly lower temperature process than conventional lipstick manufacturing to prevent damage to the heat-sensitive active ingredients in the core layer from high temperatures and to avoid affecting the precisely set glass transition temperature of the shell material. This produces an irreversible effect, thereby ensuring the final realization of all the product's preset functions.

[0024] In a preferred embodiment, to improve product quality, step c further includes vacuum degassing of the mixed materials.

[0025] In summary, the present invention has at least one of the following beneficial technical effects: 1. This invention achieves a synergistic effect of long-term sustained release and targeted delivery of active ingredients by constructing a unique core-shell structured functional fiber and utilizing the chemical properties of pullulan and chitosan in the shell. The basic sustained-release effect of pullulan upon contact with water, combined with the targeted accelerated release of chitosan through specific enzymatic hydrolysis in the damaged lip area, allows the product to intelligently regulate the output of active ingredients. This not only prolongs the duration of action but also precisely concentrates high concentrations of active ingredients in the areas most in need of repair, significantly improving the efficiency and precision of prevention and treatment.

[0026] 2. This invention significantly improves the user experience of the product and provides an immediate optical soft-focus effect. This is thanks to the precise design of the glass transition temperature of the nanofiber shell material, which gives it temperature-sensitive self-plasticizing properties. After the product is applied to the lips, the fibers rapidly transform from a firm glassy state to a soft rubbery state under the influence of body temperature, resulting in an extremely smooth and seamless feel. At the same time, the microscopic morphological changes on the fiber surface caused by this phase transition effectively scatter light, instantly blurring lip lines visually.

[0027] 3. This invention enhances the product's adhesion and staying power on the lips, extending its effective duration. On one hand, its core function is based on one-dimensional nanofibers, a morphology that allows it to penetrate deep into the lip grooves like micro-anchors, forming a physical lock. On the other hand, the chitosan component in the shell possesses excellent bioadhesiveness. This dual mechanism of "physical locking + chemical adhesion" enables the product to form a stable and long-lasting functional film on the lips, effectively resisting wear caused by daily activities such as eating and talking.

[0028] 4. This invention effectively protects the stability and bioactivity of the core active ingredients, ensuring the ultimate realization of product efficacy. Through coaxial electrospinning technology, heat-sensitive and easily oxidized active ingredients are precisely encapsulated within the fiber core, forming a physical barrier and preventing direct contact with complex components in the matrix. Combined with the subsequent low-temperature preparation process, from source to finished product, this double protection ensures that the active ingredients are not degraded or destroyed during preparation and storage, guaranteeing consistent efficacy throughout the product's shelf life.

[0029] 5. This invention solves the compatibility problem between functional nanomaterials and traditional ointment matrices through innovative preparation processes, ensuring the high quality of the final product. In particular, the low-temperature ultrafine pulverization process processed the nanomaterials into uniformly disperseable micron-sized short-cut powders without damaging the core functional structure of the fibers. This allows for seamless integration into the oil and wax matrix, avoiding problems such as graininess, agglomeration, or uneven dispersion that may occur with conventional mixing. This provides a fundamental guarantee for the product's excellent skin feel and stable efficacy release.

[0030] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but the scope of protection of the present invention is not limited thereto.

[0031] Example 1 This embodiment provides a method for preparing a lipstick for preventing and treating chapped lips, the specific steps of which are as follows: Step 1: Preparation of the core layer "high-concentration active ingredient composite emulsion": Weigh 1.0g of shikonin and 1.5g of glycyrrhetinic acid, add them to 85.5g of medium-chain triglycerides, and stir to dissolve in a 45℃ water bath. Then add 3.0g of a mixture of ceramide III and phytosphingosine and 5.0g of sea buckthorn fruit oil, and mix well. Under high-speed shearing at 10,000rpm, slowly add 4.0g of deionized water to the above oil phase, and continue shearing for 15 minutes to obtain a W / O type "core layer fluid".

[0032] Step Two: Preparation of the Shell-Layer "Temperature-Sensitive Self-Plasticizing Dual-Response Polymer Solution" Weigh 15.0 g of chitosan and dissolve it in a 1.5% (v / v) glacial acetic acid aqueous solution; separately weigh 60.0 g of pullulan and dissolve it in deionized water. Mix the two solutions, at which point the dry weight ratio of pullulan to chitosan is 4:1. Adjust the total polymer concentration to 10% (w / v) and adjust the final pH to 4.5. The "shell fluid" is obtained.

[0033] Step 3: Construction of Functional Core-Shell Nanofibers. The core fluid from Step 1 and the shell fluid from Step 2 were pumped separately into a coaxial electrospinning apparatus. Process parameters were set as follows: voltage 20kV, distance between the spinneret and the receiving roller 18cm, core fluid flow rate 0.2mL / h, and shell fluid flow rate 1.2mL / h. Spinning was carried out at 22℃ and 45% relative humidity, and the nanofiber mat was collected.

[0034] Step 4: Formulation modification of nanofibers. The nanofiber felt collected in Step 3 was immersed in liquid nitrogen and frozen for 5 minutes. It was then quickly transferred to a pre-cooled low-temperature ultrafine pulverizer and ground for 2 cycles, each cycle consisting of 1.5 minutes of grinding and 1.5 minutes of cooling, to obtain short-cut nanofiber powder.

[0035] Step 5: To finalize the lipstick product, weigh the components according to the following proportions by weight: Nanofiber powder prepared in step four: 3.5 parts Candelilla wax: 10.0 parts Beeswax: 5.0 parts Carnauba wax: 5.0 parts Jojoba seed oil: 35.0 parts Shea butter: 30.0 parts Meadowfoam seed oil: calculated based on replenishing to 100 parts. Tocopherol: 1.0 part Bisabolol: 0.5 parts All wax and oil components were melted at 58°C, and tocopherol and bisabolol were added and stirred until homogenized. Nanofiber powder was then added and homogenized for 25 minutes. After vacuum degassing, the mixture was poured into molds, cooled and set at 8°C, and then demolded to obtain the finished product.

[0036] Example 2 This embodiment provides a method for preparing a lipstick for preventing and treating chapped lips, the specific steps of which are as follows: Step 1: Preparation of the core layer "high-concentration active ingredient composite emulsion": Weigh 0.5g of shikonin and 1.0g of glycyrrhetinic acid, add them to 89.5g of medium-chain triglycerides, and stir to dissolve in a 40℃ water bath. Then add 2.0g of a mixture of ceramide III and phytosphingosine, and 4.0g of sea buckthorn fruit oil, and mix thoroughly. Under high-speed shearing at 8,000rpm, slowly add 3.0g of deionized water to the above oil phase, and continue shearing for 20 minutes to obtain a W / O type "core layer fluid".

[0037] Step Two: Preparation of the Shell-Layer "Temperature-Sensitive Self-Plasticizing Dual-Response Polymer Solution" Weigh 20.0 g of chitosan and dissolve it in a 1.0% (v / v) glacial acetic acid aqueous solution; separately weigh 60.0 g of pullulan and dissolve it in deionized water. Mix the two solutions, at which point the dry weight ratio of pullulan to chitosan is 3:1. Adjust the total polymer concentration to 8% (w / v) and adjust the final pH to 4.0. The "shell fluid" is obtained.

[0038] Step 3: Construction of Functional Core-Shell Nanofibers. The core fluid from Step 1 and the shell fluid from Step 2 were pumped separately into a coaxial electrospinning apparatus. Process parameters were set as follows: voltage 15kV, distance between the spinneret and the receiving roller 15cm, core fluid flow rate 0.1mL / h, and shell fluid flow rate 0.8mL / h. Spinning was carried out at 20℃ and 40% relative humidity, and the nanofiber mat was collected.

[0039] Step 4: Formulation modification of nanofibers. The nanofiber felt collected in Step 3 was immersed in liquid nitrogen and frozen for 10 minutes. It was then quickly transferred to a pre-cooled low-temperature ultrafine pulverizer and ground for 3 cycles, each cycle consisting of 1 minute of grinding and 2 minutes of cooling, to obtain short-cut nanofiber powder.

[0040] Step 5: To finalize the lipstick product, weigh the components according to the following proportions by weight: Nanofiber powder prepared in step four: 2.0 parts Candelilla wax: 8.0 parts Beeswax: 4.0 parts Carnauba wax: 3.0 parts Jojoba seed oil: 40.0 parts Shea butter: 31.8 parts Meadowfoam seed oil: calculated based on replenishing to 100 parts. Tocopherol: 0.5 parts Bisabolol: 0.2 parts All wax and oil components are melted at 55°C, and tocopherol and bisabolol are added and stirred until homogenized. Nanofiber powder is then added and homogenized for 20 minutes. After vacuum degassing, the mixture is poured into molds, cooled and set at 10°C, and then demolded to obtain the finished product.

[0041] Example 3 This embodiment provides a method for preparing a lipstick for preventing and treating chapped lips, the specific steps of which are as follows: Step 1: Preparation of the core layer "high-concentration active ingredient composite emulsion": Weigh 1.5g of shikonin and 2.5g of glycyrrhetinic acid, add them to 76.0g of medium-chain triglycerides, and stir to dissolve in a 45℃ water bath. Then add 4.0g of a mixture of ceramide III and phytosphingosine and 10.0g of sea buckthorn fruit oil, and mix well. Under high-speed shearing at 12,000rpm, slowly add 6.0g of deionized water to the above oil phase, and continue shearing for 10 minutes to obtain a W / O type "core layer fluid".

[0042] Step Two: Preparation of the "Temperature-Sensitive Self-Plasticizing Dual-Response Polymer Solution" for the Shell Layer. Weigh 10.0 g of chitosan and dissolve it in a 2.0% (v / v) aqueous solution of glacial acetic acid; separately weigh 50.0 g of pullulan and dissolve it in deionized water. Mix the two solutions, at which point the dry weight ratio of pullulan to chitosan is 5:1. Adjust the total polymer concentration to 12% (w / v) and adjust the final pH to 5.0. The "shell fluid" is obtained.

[0043] Step 3: Construction of Functional Core-Shell Nanofibers. The core fluid from Step 1 and the shell fluid from Step 2 were pumped separately into a coaxial electrospinning apparatus. Process parameters were set as follows: voltage 25kV, distance between the spinneret and the receiving roller 20cm, core fluid flow rate 0.3mL / h, and shell fluid flow rate 1.5mL / h. Spinning was carried out at 25℃ and 50% relative humidity, and the nanofiber mat was collected.

[0044] Step 4: Formulation modification of nanofibers. The nanofiber felt collected in Step 3 was immersed in liquid nitrogen and frozen for 8 minutes. It was then quickly transferred to a pre-cooled low-temperature ultrafine pulverizer and ground for 4 cycles, each cycle consisting of 1.5 minutes of grinding and 1 minute of cooling, to obtain short-cut nanofiber powder.

[0045] Step 5: To finalize the lipstick product, weigh the components according to the following proportions by weight: Nanofiber powder prepared in step four: 5.0 parts Candelilla wax: 12.0 parts Beeswax: 7.0 parts Carnauba wax: 6.0 parts Jojoba seed oil: 30.0 parts Shea butter: 28.2 parts Meadowfoam seed oil: calculated based on replenishing to 100 parts. Tocopherol: 1.0 part Bisabolol: 0.8 parts All wax and oil components are melted at 60°C, and tocopherol and bisabolol are added and stirred until homogenized. Nanofiber powder is then added and homogenized for 30 minutes. After vacuum degassing, the mixture is poured into molds, cooled and set at 4°C, and then demolded to obtain the finished product.

[0046] Comparative Example Comparative Example 1: Compared with Example 1, the difference is that, instead of preparing functional nanofiber powder, all the active ingredients (shikonin, glycyrrhetinic acid, ceramide III and phytosphingosine, and sea buckthorn fruit oil) used in step one of Example 1 to prepare the "core fluid" were directly added to the molten lipstick base in step five for mixing. All other steps were the same.

[0047] Comparative Example 2: Compared with Example 1, the difference is that in step two, when preparing the "shell fluid", only pullulan was used as the shell polymer, and chitosan was not added. Everything else was the same.

[0048] Comparative Example 3: Compared with Example 1, the difference is that in step two, when preparing the "shell fluid", the dry weight ratio of pullulan to chitosan was adjusted from 4:1 to 1:1. All other aspects are the same.

[0049] Comparative Example 4: Compared with Example 1, the difference is that coaxial electrospinning is not used in step three. Instead, the "core fluid" from step one and the "shell fluid" from step two are pre-mixed mechanically until homogeneous, and then uniaxial electrospinning technology is used for spinning. All other aspects are the same.

[0050] Comparative Example 5: Compared with Example 1, the difference is that in step four, low-temperature ultrafine grinding was not used. Instead, the nanofiber felt collected in step three was ground at room temperature using a conventional grinder. All other aspects were the same.

[0051] Comparative Example 6: Compared with Example 1, the difference is that in step five, during the final shaping, the temperature at which the nanofiber powder is dispersed in the lipstick matrix is ​​increased from 58°C to the conventional 85°C. All other aspects are the same.

[0052] Test Example 1: In Vitro Active Substance Release Performance Test I. Experimental Instructions This test aims to evaluate the in vitro active ingredient release characteristics of the samples of Example 1 and Comparative Examples 1, 2, and 4 of the present invention in a simulated lip environment, so as to verify their ability to provide long-lasting sustained release and enzyme-responsive targeted release.

[0053] 1. Experimental Instruments and Reagents: Franz vertical diffusion cell system, constant temperature water bath circulator, biomimetic skin membrane, artificial saliva (pH 6.8, containing NaCl, KCl, CaCl2, NaHCO3, etc.), lysozyme, high performance liquid chromatograph (HPLC).

[0054] 2. Experimental Procedure (1) Comparative test of sustained-release performance (Example 1 vs Comparative Example 1 vs Comparative Example 4) Take several Franz diffusion cells, each with a receiving chamber volume of 5.0 mL and an effective diffusion area of ​​1.77 cm². 2 A bionic skin membrane is installed between the donor chamber and the receiver chamber.

[0055] The receiving chamber was filled with artificial saliva without lysozyme and placed in a constant temperature water bath at 34±1℃, and continuously stirred with a magnetic stirrer at a rate of 100rpm.

[0056] Accurately weigh 15 mg of each of the ointment samples from Example 1, Comparative Example 1, and Comparative Example 4, and apply them evenly to the donor chamber side of the biomimetic skin membrane.

[0057] At time points of 0.5, 1, 2, 4, 6, and 8 hours, 0.5 mL of receiving liquid was drawn from the sampling port of the receiving chamber, and blank artificial saliva of equal temperature and volume was immediately added.

[0058] After all samples were filtered through a microporous membrane, the concentration of the core active ingredient (shikonin) was determined by HPLC, and the cumulative release was calculated.

[0059] (2) Comparative test of enzyme response performance (Example 1 vs. Comparative Example 2) The experimental setup is basically the same as step (1), but two sets of experiments are set up in parallel for the samples of Example 1 and Comparative Example 2.

[0060] Group A: The receiving chamber contains artificial saliva that does not contain lysozyme.

[0061] Group B: The receiving chamber contains artificial saliva containing a standard concentration (200 U / mL) of lysozyme.

[0062] Samples were taken and analyzed at the same time points, and the differences in the cumulative release curves of the two groups of samples under conditions with and without lysozyme were compared.

[0063] II. Experimental Data Comparison of in vitro cumulative release performance of different samples in artificial saliva (enzyme-free)

[0064] Comparison of in vitro cumulative release performance of Example 1 and Comparative Example 2 in different media

[0065] III. Summary Experimental results show that the sample of Example 1 exhibits significantly better active ingredient release regulation capabilities than the comparative examples. Compared with Comparative Example 1 (direct addition of active ingredient), the release of active ingredient in Example 1 is stable and linear within 8 hours, avoiding the initial rapid burst release. This directly confirms that the core-shell structure designed in this invention can serve as an effective physical barrier, stably encapsulating the active ingredient within the fiber, thereby achieving long-lasting and continuous release and extending the effective action time of the active ingredient on the lip. The release rate of Comparative Example 4 (using uniaxial electrospinning) is between the two, indicating that an incomplete core-shell structure cannot achieve the ideal sustained-release effect, thus conversely proving the necessity of constructing a complete core-shell structure using coaxial electrospinning technology in this invention.

[0066] In Example 1, the release rate of the active ingredient in artificial saliva containing lysozyme was significantly faster than in the enzyme-free environment, while the release curves of Comparative Example 2 (which does not contain chitosan in its shell) showed no significant difference between the enzyme-containing and enzyme-free environments. This result clearly reveals the dual-response release mechanism constructed in this invention. First, pullulan slowly swells upon contact with water, providing a basic and continuous background release; second, the chitosan component is specifically degraded by lysozyme, triggering targeted accelerated release. This mechanism enables the product of this invention to intelligently release higher concentrations of active ingredients as needed in the dry, cracked areas of the lips (where lysozyme concentration is typically high), achieving precise repair.

[0067] In summary, this invention successfully constructs an intelligent delivery system integrating long-acting sustained release and enzyme-responsive targeted release by encapsulating the active ingredient in core-shell nanofibers composed of pullulan and chitosan. This system not only ensures a continuous supply of the active ingredient through its stable physical structure but also achieves on-demand enhanced release under specific physiological signals through ingenious chemical design, thereby enabling more efficient and precise prevention and treatment of chapped lips.

[0068] Test Example 2: Active ingredient protection effect and product stability test I. Experimental Instructions This test aims to evaluate the ability of the samples of Example 1 and Comparative Examples 1 and 6 of the present invention to protect the core heat-sensitive active ingredient under accelerated aging conditions, so as to verify the comprehensive effect of the core-shell encapsulation structure and low-temperature preparation process of the present invention in improving product stability.

[0069] 1. Experimental instruments and reagents: precision electronic balance, constant temperature incubator, ultrasonic cleaner, high-speed centrifuge, high-performance liquid chromatograph (HPLC), chromatographic grade methanol, formic acid.

[0070] 2. Experimental steps (1) Sample preparation and accelerated aging Take approximately 0.5g of the finished paste from Example 1, Comparative Example 1, and Comparative Example 6 and place it in a separate, sealed glass sample bottle. Set up 3 parallel samples for each sample.

[0071] All sample vials were placed in a constant temperature incubator at 40±2℃ and stored in the dark for 4 weeks for accelerated stability testing.

[0072] Meanwhile, samples from the same batch were stored at 4°C in the dark as an initial control for week 0.

[0073] (2) Determination of active ingredient content At the start of the test (week 0) and at the end of the test (week 4), approximately 50 mg of the paste sample was accurately weighed from the sample vial.

[0074] Dissolve the weighed sample in an appropriate amount of organic solvent (such as tetrahydrofuran), and then dilute to a volumetric flask with methanol.

[0075] The solution was sonicated for 15 minutes to ensure complete dissolution of the active ingredient, and then centrifuged at 8000 rpm for 10 minutes.

[0076] The supernatant was collected, filtered through a 0.22 μm microporous membrane, and then injected into an HPLC system for analysis.

[0077] Chromatographic conditions: C18 column (4.6 mm × 250 mm, 5 μm); mobile phase: methanol: 0.1% formic acid aqueous solution = 85:15 (v / v); flow rate: 1.0 mL / min; column temperature: 30 °C; detection wavelength set to the maximum absorption wavelength of shikonin.

[0078] (3) Data processing The actual content of shikonin in each sample was calculated based on the peak area.

[0079] Retention rate of active ingredient (%) = (content measured at 4 weeks / content measured at 0 weeks) × 100%.

[0080] II. Experimental Data Table 5: Comparison of core active ingredient retention rates of different samples after 4 weeks under accelerated conditions at 40℃

[0081] III. Summary The experimental results clearly demonstrate the significant advantages of this invention in protecting the core active ingredient. After 4 weeks of accelerated aging, the sample in Example 1 showed a much higher retention rate of the core active ingredient than Comparative Example 1 and Comparative Example 6. Comparative Example 1, by directly mixing the active ingredient with the matrix, resulted in significant degradation of the active ingredient, proving that the core-shell structure designed in this invention plays a crucial physical barrier role. This structure effectively encapsulates the unstable active ingredient within the fiber core, acting like a miniature "vault," isolating it from the complex oil and wax matrix and the external environment, thereby greatly slowing down its degradation rate during storage.

[0082] By comparing Example 1 and Comparative Example 6, the necessity of the low-temperature preparation process of this invention is clearly evident. Although Comparative Example 6 also used core-shell fibers, its initial active ingredient content was significantly lower than that of Example 1 upon completion of preparation. This indicates that the traditional high-temperature process causes irreversible initial damage to the heat-sensitive active ingredient. Even with the protection of the core-shell structure, its subsequent stability is far inferior to that of Example 1, which uses a low-temperature process. The 55-60°C low-temperature dispersion process used in this invention gently integrates the functional fibers into the matrix, not only protecting the initial activity of the active ingredient but also ensuring the integrity and density of the polymer shell structure, allowing it to maximize its long-term physical shielding function.

[0083] Therefore, the superior stability of the product of this invention is not due to a single factor, but rather the inevitable result of the synergistic effect of "precise structural design" and "optimized process control." It is precisely the core-shell structure constructed through coaxial electrospinning that effectively isolates the active ingredient. Combined with the subsequent low-temperature preparation process, this ensures that the structure and the active ingredient are not damaged during production. The combined effect of these two factors ultimately guarantees the high stability and high activity of the active ingredient throughout the product's shelf life, ensuring the final realization of the product's efficacy.

[0084] Test Example 3: Product Adhesion and Makeup Holding Performance Test I. Experimental Instructions This test aims to evaluate the adhesion and makeup-holding ability of the samples of Example 1 and Comparative Examples 1 and 2 under simulated rinsing conditions, so as to verify the role of the one-dimensional nanofiber structure and chitosan component of the present invention in improving the adhesion of the product to the lips.

[0085] 1. Experimental instruments and reagents: analytical balance (accuracy 0.1mg), biomimetic skin base (collagen casing), constant flow pump, artificial saliva (same as test example 1), constant temperature drying oven.

[0086] 2. Experimental steps (1) Sample preparation and application Cut the collagen casing into several 3cm pieces. A square substrate of cm was dried in a constant temperature drying oven at 60℃ for 30 minutes, and then accurately weighed using an analytical balance. The weight of this substrate was recorded as: .

[0087] Accurately weigh approximately 20 mg of the ointment samples from Example 1, Comparative Example 1, and Comparative Example 2, and apply them evenly to the weighed base using a standard application tool.

[0088] The substrate coated with the sample was weighed again and recorded as follows: Net weight of the paste before rinsing .

[0089] (2) Simulated flushing The substrate coated with the sample is fixed in a specially designed rinsing tank, with its surface at a 45° angle to the horizontal plane.

[0090] Using a constant flow pump, artificial saliva at 34±1℃ was continuously rinsed onto the sample surface at a flow rate of 5 mL / min for 5 minutes.

[0091] (3) Result determination After rinsing, carefully remove the substrate and place it in a 60℃ constant temperature drying oven to dry for 1 hour until constant weight is achieved.

[0092] Weigh the rinsed and dried substrate again and record the weight as follows: Net weight of the ointment after rinsing .

[0093] Each sample was tested in triplicate, and the average value was taken.

[0094] II. Experimental Data Comparison of paste residue rates of different samples after simulated rinsing

[0095] III. Summary The experimental results strongly demonstrate the superior adhesion and makeup-holding performance of the product of this invention. The residue rate of Example 1 was significantly higher than that of Comparative Examples 1 and 2, indicating that it adheres more firmly to the substrate surface and effectively resists external physical erosion. Comparative Example 1, lacking any fibrous structure, had its active ingredients and matrix remaining on the surface only through simple physical adsorption, making it easily carried away by flowing liquids, thus resulting in the lowest residue rate. This, in turn, proves that the one-dimensional nanofiber network structure introduced in this invention plays a crucial physical anchoring role, providing a basic adhesion framework for the product.

[0096] By comparing Example 1 and Comparative Example 2, the underlying mechanism of this invention can be further revealed. Although Comparative Example 2 also contains a fibrous structure, its residue rate is much lower than that of Example 1. This clearly shows that the fibrous morphology alone is insufficient to achieve the best adhesion effect; the presence of the chitosan component is crucial. The mechanism lies in the fact that chitosan, as a cationic polymer, has a natural electrostatic attraction with the normally negatively charged skin or mucous membrane surface. Therefore, the nanofibers of this invention are not only a physical framework but also a smart framework with a "chemical adhesive," capable of actively and firmly adsorbing onto the lip surface through bioelectrostatic adhesion.

[0097] In summary, the superior makeup-holding performance of this invention is the result of the synergistic effect of its unique "physical morphology" and "chemical properties." The microscopic network formed by the interwoven one-dimensional nanofibers acts like countless tiny "hooks," penetrating deep into the grooves of the lips to form a physical lock; while the chitosan in the shell provides these "hooks" with strong chemical adhesion through electrostatic interactions. This dual mechanism of "physical locking + chemical adhesion" enables the product of this invention to form a stable and long-lasting functional film on the lips, thereby greatly extending the action time of the active ingredients and ensuring the realization of its long-lasting function.

[0098] Test Example 4: Sensory Performance Evaluation of the Product I. Experimental Instructions This test aims to compare the differences in application smoothness, adherence, and texture between the samples of Example 1 of this invention and Comparative Examples 3, 5, and 6 through sensory evaluation by professionals, in order to verify the unique skin feel experience brought about by the temperature-sensitive self-plasticizing technology and optimized preparation process of this invention.

[0099] 1. Experimental Personnel and Environment: Twelve evaluators with professional skin sensory evaluation training were recruited. All evaluations were conducted in a standard sensory evaluation room with a temperature of 23±2℃ and a relative humidity of 50±5%.

[0100] 2. Experimental steps (1) Sample preparation and coding The samples from Example 1, Comparative Example 3, Comparative Example 5, and Comparative Example 6 were randomly coded to achieve double-blind testing.

[0101] Before evaluation, all samples were kept at a constant temperature in the evaluation room for 30 minutes.

[0102] (2) Evaluation process The evaluator cleaned the skin on the inside of the forearm and marked four separate evaluation areas using a delineation template.

[0103] Using a standard smearing tool, the lab assistant applies an equal amount (approximately 10 mg) of coded sample evenly to each area for the evaluator.

[0104] Evaluators assessed the product's feel on the skin immediately after application and completed a questionnaire within one minute. Between evaluations of different samples, fingers were cleaned with water and a non-woven cloth to eliminate interference.

[0105] Evaluation indicators and scoring criteria: A 10-point scoring system is used.

[0106] Smoothness of application: Evaluates the spread and silky feel of the product when applied. 1 point = very rough / not smooth, 10 points = extremely silky / easy to spread.

[0107] Fit: Evaluates how well the product blends with the skin. 1 point = very superficial / not fitting, 10 points = perfectly fitting / integrated into the skin.

[0108] Graininess: Evaluates the perceptible microparticles in the product. 1 point = no graininess, 10 points = very rough / severe graininess.

[0109] (3) Data processing Collect all the rating sheets from the evaluators, remove invalid data, and calculate the average score for each sample on each indicator.

[0110] II. Experimental Data Comparison of average scores of sensory performance evaluation of different samples

[0111] III. Summary Sensory evaluation results clearly demonstrate that the sample in Example 1 exhibits unparalleled advantages in all core skin-feel dimensions. Its extremely high smoothness, adherence, and virtually imperceptible particle size directly stem from the core innovation of this invention—temperature-sensitive self-plasticizing technology. Its mechanism of action lies in the fact that this invention precisely controls the ratio of the shell material to achieve its glass transition temperature (…). Located near body temperature. When the cream is applied to the skin, the fiber shell absorbs heat and quickly transforms from a hard glassy state to a soft rubbery state. This transformation allows the originally independent fibers to soften and deform instantly, perfectly conforming to the micro-grooves of the skin, resulting in an extremely smooth and seamless unique skin feel.

[0112] The comparison with the comparative examples further confirms the scientific validity of the above mechanism and the necessity of the process of this invention. Comparative Example 3, due to improper shell layer ratio, [failed to meet certain conditions]. Deviating from the ideal range prevented sufficient phase transition at body temperature, causing the fibers to retain high stiffness, resulting in a rough feel and poor conformation to the skin. Comparative Example 5 highlights the importance of the preparation process; its conventional pulverization method destroyed the independent morphology of the fibers, forming coarse aggregates and leading to a disastrous grainy texture. This conversely proves that the low-temperature ultrafine pulverization process used in this invention is a crucial prerequisite for completely preserving the morphology of individual fibers and ensuring the subsequent temperature-sensitive self-plasticization effect.

[0113] Finally, the results of Comparative Example 6 show that even with the correct fibers, improper heat treatment can still ruin the final sensory experience. Traditional high-temperature manufacturing processes are sufficient to affect the molecular structure of the shell polymer, thereby altering its precisely defined... The temperature-sensitive self-plasticizing effect is significantly reduced due to the low temperature. Therefore, the superior skin feel of the product of this invention is the result of the synergistic effect of "precision material design" and "end-to-end process assurance". It not only relies on functional fibers with specific glass transition temperatures, but also on a series of protective processes from low-temperature pulverization to low-temperature dispersion to ensure that this core physical property is completely brought from the laboratory to the final product, thereby providing users with an unprecedented comfortable experience.

[0114] Test Example 5: Optical Soft Focus Performance Test I. Experimental Instructions This test aims to quantitatively evaluate the light scattering ability of the samples of Example 1 and Comparative Examples 1 and 3 under simulated body temperature conditions, i.e., the optical soft-focus effect, in order to verify the contribution of the temperature-sensitive self-plasticizing technology of the present invention to improving visual appearance.

[0115] 1. Experimental Instruments and Materials: Integrating sphere colorimeter (for measuring specular and diffuse reflection), constant temperature heating stage, standard blackboard (for simulating a dark lip background), automated thin film preparation apparatus.

[0116] 2. Experimental Procedure (1) Sample preparation The paste samples of Example 1, Comparative Example 1, and Comparative Example 3 were placed in sample dishes respectively.

[0117] Using an automated thin film preparation instrument, each sample was uniformly coated onto a standard blackboard to form a wet film with a thickness of 20 μm.

[0118] (2) Sample processing and measurement The standard blackboard coated with the sample was placed on a constant temperature heating table at 34±1℃ and left to stand for 5 minutes to fully simulate the temperature environment of the product on the skin of the lips and trigger possible changes in the physical state.

[0119] Preheat integrating sphere colorimeter. Place the sample plate, after it has reached constant temperature, into the measuring port.

[0120] The specular gloss and diffuse reflectance (%) of each sample coating at 60° were measured. The lower the specular gloss, the more matte the surface; the higher the diffuse reflectance, the stronger the ability to scatter light and the better the soft-focus effect.

[0121] Each sample was measured at three different locations, and the average value was taken as the final result.

[0122] II. Experimental Data Comparison of optical properties of different sample coatings at simulated body temperature

[0123] III. Summary Experimental data clearly reveal the unique advantages of the product of this invention in terms of optical performance. The sample coating of Example 1 exhibits extremely low specular gloss and extremely high diffuse reflectance, proving that it can scatter most of the incident light in all directions, thereby producing an excellent soft-focus effect and effectively blurring minor imperfections on the substrate. In contrast, Comparative Example 1, which contains no fibers, exhibits the characteristics of a traditional oil-wax matrix with high gloss and low diffuse reflectance, while the coating containing fibers... Comparative Example 3, with mismatched fibers, showed a slight change in optical performance but still fell far short of the soft-focus effect, strongly demonstrating the technical innovation of this invention.

[0124] The mechanism of this unique optical effect is rooted in the temperature-sensitive self-plasticization technology at the core of this invention. The functional nanofibers in Example 1 have a glass transition temperature (GTH) of their shell material. Precisely designed to be near body temperature, the fibers rapidly transform from a rigid, glassy state at room temperature to a soft, rubbery state when the paste is applied to a substrate simulating body temperature. This phase transition causes a reshaping of the fiber surface's microstructure, forming an irregular, micro-rough surface that efficiently scatters light. It is this surface, composed of countless micro-scattering units, that transforms specular reflection into diffuse reflection, thus achieving instantaneous optical soft focus.

[0125] In contrast, the failure of Comparative Example 3, conversely, verifies the correctness of the above mechanism. The improper chemical composition of its fibrous shell led to its… Temperatures are much higher than body temperature. Therefore, under experimental conditions, the fibers cannot undergo an effective phase transition and remain in their rigid glassy state, failing to form an effective diffuse reflection surface, thus significantly reducing the optical effect. In summary, the optical soft-focus function of this invention is not simply due to the addition of fibers, but rather through the precise design of the physicochemical properties of the fiber shell, giving it a unique temperature-sensitive response capability. This allows it to actively change its optical properties at specific temperatures, representing a creative application of material physical properties and ultimately achieving a perfect combination of makeup and skincare functions.

[0126] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A lipstick for preventing and treating chapped lips, characterized in that, The lipstick comprises a matrix and functional nanofiber powder distributed within the matrix; The functional nanofiber powder is composed of nanofibers with a core-shell structure; The shell of the nanofiber is composed of chitosan and pullulan, and the shell material is vitrified. The temperature is between 30°C and 35°C. The core layer of the nanofiber contains active ingredients for preventing or treating chapped lips; The components of the lipstick, by weight, include: The functional nanofiber powder: 2-5 parts; Wax component: 15-25 parts; Oil component: 50-70 parts; Functional additives: 1-2 parts.

2. The lipstick for preventing and treating chapped lips according to claim 1, characterized in that, The active ingredients in the core layer include shikonin, glycyrrhetinic acid, and a biomimetic sebum repair agent composed of ceramide, phytosphingosine, and sea buckthorn fruit oil.

3. The lipstick for preventing and treating chapped lips according to claim 1, characterized in that, The dry weight ratio of pullulan to chitosan in the shell is 3:1 to 5:

1.

4. The lipstick for preventing and treating chapped lips according to claim 1, characterized in that, The functional nanofiber powder is composed of short-cut nanofibers with a length of 50 to 100 micrometers.

5. A lipstick for preventing and treating chapped lips according to claim 1, characterized in that, The wax component is selected from at least one of candelilla wax, beeswax, and carnauba wax; the oil component is selected from at least one of jojoba seed oil, shea butter, and meadowfoam seed oil.

6. The manufacturing process of a lipstick for preventing and treating chapped lips according to any one of claims 1-5, characterized in that, Includes the following steps: a. Using coaxial electrospinning technology, a core-shell structured nanofiber felt is spun from a core fluid containing active substances and a shell fluid containing chitosan and pullulan. b. The core-shell structured nanofiber felt is subjected to low-temperature ultrafine pulverization to obtain functional nanofiber powder; c. The functional nanofiber powder is dispersed in a molten lipstick matrix at a temperature of 55-60°C, and then homogenized, filled, and cooled to form the final product.

7. The preparation process according to claim 6, characterized in that, Step a specifically includes: a1 prepared active ingredients such as shikonin and glycyrrhetinic acid into a W / O type emulsion, which was used as the core fluid; a2 dissolves chitosan and pullulan in a solvent and controls the dry weight ratio of the two to be 3:1 to 5:1 as a shell fluid.

8. The preparation process according to claim 6, characterized in that, The process parameters for coaxial electrospinning in step a are: voltage 15-25kV, receiving distance 15-20cm, core fluid flow rate 0.1-0.3mL / h, and shell fluid flow rate 0.8-1.5mL / h.

9. The preparation process according to claim 6, characterized in that, The low-temperature ultrafine pulverization in step b specifically includes: immersing the nanofiber felt in liquid nitrogen for freezing, and then using mechanical force to pulverize it into powder with a length of 50 to 100 micrometers.

10. The preparation process according to claim 6, characterized in that, The dispersion process described in step c also includes vacuum degassing of the mixed materials.

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