A moisturizing skin care cosmetic and a method of preparing the same

Abstract

This invention relates to a moisturizing and skin-nourishing cosmetic and its preparation method, belonging to the field of cosmetic technology. The cosmetic comprises self-regulating phase change liposomes and cosmetically acceptable excipients. The functional oil-phase self-regulating phase change liposome has a unique wall structure, consisting of a first type of phospholipid, a second type of phospholipid, and a functional oil phase permeating a bilayer formed by the two; wherein the phase transition temperature of the first type of phospholipid is 32-35℃, the phase transition temperature of the second type of phospholipid is 25-28℃, and the weight ratio of the two is 60:30 to 70:40; the functional oil phase accounts for 10-25% of the total weight of the wall material. The liposome's internal aqueous phase encapsulates a multi-component moisturizing composition. The cosmetic of this invention can adjust the release rate of moisturizing ingredients according to the slight temperature difference caused by changes in skin humidity, achieving a dynamic moisturizing effect. Simultaneously, through a biomimetic lipid structure, it synergistically repairs the skin barrier, providing long-lasting moisturizing and skin-nourishing functions.

Description

Technical Field

[0001] This application relates to the field of cosmetic technology, and in particular to a moisturizing and skin-nourishing cosmetic and its preparation method. Background Technology

[0002] The skin barrier function is closely related to the hydration state of the stratum corneum. Natural moisturizing factors and intercellular lipids within the stratum corneum together form a dynamic moisturizing system that prevents excessive moisture loss and maintains skin suppleness. When this system is damaged or the external environment is dry, it leads to increased skin moisture loss, causing a series of problems such as dryness, tightness, and sensitivity.

[0003] Currently, moisturizing products on the market primarily function through the following methods: first, adding hygroscopic ingredients to absorb moisture from the environment or deep within the skin; second, forming a occlusive film on the skin surface to reduce moisture evaporation; and third, replenishing the skin's own moisturizing factors. However, their mode of action is unidirectional and cannot sense or respond to real-time changes in the skin's moisture needs. For example, when the skin is already relatively moist, highly hygroscopic ingredients may continue to absorb water, while occlusive agents may hinder the skin's normal respiration; conversely, when the skin is dry and urgently needs moisture, the release and penetration efficiency of active ingredients may not reach its peak. This mismatch between supply and demand limits the efficiency and user experience of moisturizing products.

[0004] In recent years, liposomes, nanoparticles, and other carrier technologies have been introduced into the cosmetics field to improve the stability, permeability, and targeting of active ingredients. However, most carriers in existing technologies have limited functions, primarily serving as delivery tools, and their release behavior is mostly passive diffusion or dependent on simple pH and enzyme responses. Summary of the Invention

[0005] This application provides a moisturizing and skin-nourishing cosmetic product to improve the above-mentioned problems.

[0006] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a moisturizing and skin-nourishing cosmetic product, comprising: Self-regulating phase change liposomes and cosmetically acceptable excipients; The wall material of the self-regulating phase change liposome includes a first type of phospholipid, a second type of phospholipid, and a functional oil phase. The aqueous phase of the self-regulating phase change liposome encapsulates a multi-component moisturizing composition. The phase transition temperature of the first type of phospholipid is 32 to 35 degrees Celsius, and the phase transition temperature of the second type of phospholipid is 25 to 28 degrees Celsius. The weight ratio of type I phospholipids to type II phospholipids is 60:30 to 70:40; The functional oil phase permeates into the phospholipid bilayer composed of type I phospholipids and type II phospholipids, and the weight of the functional oil phase accounts for 10% to 25% of the total weight of the wall material.

[0007] In conjunction with the first aspect, optionally, the first type of phospholipid is selected from hydrogenated soybean lecithin, hydrogenated egg yolk lecithin, or distearate phosphatidylcholine; The second type of phospholipids is selected from dipalmitoylphosphatidylcholine, dimyristoylphosphatidylcholine, or dilauroylphosphatidylcholine.

[0008] In conjunction with the first aspect, optionally, the functional oil phase includes sterols and unsaturated fatty acid esters; Sterol compounds are phytosterols or cholesterol; The unsaturated fatty acid esters are flaxseed oil glycerides, sunflower seed oil glycerides, or oleic acid glycerides.

[0009] In conjunction with the first aspect, optionally, in the functional oil phase, the weight ratio of sterol compounds to unsaturated fatty acid esters is 1:3 to 1:5.

[0010] In conjunction with the first aspect, optionally, the multi-component moisturizing composition includes a small molecule polyol moisturizer, a high molecular weight polymer water-locking agent, and a biomimetic component of natural moisturizing factors; Small molecule polyol moisturizers are selected from glycerin, propylene glycol, butylene glycol, pentylene glycol, or hexanediol; The polymer water-locking agent is selected from hyaluronic acid, hyaluronic acid salt, acetylated sodium hyaluronate, sodium polyglutamate, or β-glucan; The biomimetic components of the natural moisturizing factor are selected from sodium pyrrolidone carboxylate, sodium lactate, urea, or amino acids.

[0011] In conjunction with the first aspect, optionally, in the multi-component moisturizing composition, the weight ratio of the small molecule polyol moisturizer, the high molecular weight polymer water-locking agent, and the biomimetic component of the natural moisturizing factor is 15:0.5:3 to 25:2:8.

[0012] Secondly, this application proposes a method for preparing a moisturizing and skin-nourishing cosmetic, as described in the first aspect, comprising: The first type of phospholipid, the second type of phospholipid, and the functional oil phase are dissolved in an organic solvent, and the organic solvent is removed to form a lipid film; A hydrated lipid film is prepared by using an aqueous solution at a temperature above 35 degrees Celsius, which is then homogenized by high-speed shearing and high-pressure microfluidization, and mixed with an aqueous solution of a multi-component moisturizing composition to form a nano-dispersion. The nano-dispersion was subjected to a programmed cooling process, which included isothermal holding in the range of 32°C to 35°C and in the range of 25°C to 28°C, respectively, to obtain a dispersion of self-regulating phase change liposomes. A dispersion of self-regulating phase change liposomes is mixed with cosmetically acceptable excipients to create a moisturizing and skin-nourishing cosmetic.

[0013] In conjunction with the second aspect, optionally, the nano-dispersion is subjected to a programmed cooling process, which includes isothermal holding in the range of 32°C to 35°C and in the range of 25°C to 28°C, respectively, to obtain a dispersion of self-regulating phase change liposomes, including: The cooling rate of the programmed cooling process is 0.5 degrees Celsius to 1 degree Celsius per minute; The temperature is maintained at 32 to 35 degrees Celsius for 20 to 40 minutes. The temperature is maintained at a constant temperature between 25 and 28 degrees Celsius for 20 to 40 minutes.

[0014] Thirdly, this application proposes the use of a moisturizing and skin-nourishing cosmetic as described in any of the first aspects for the preparation of a topical skin product, characterized in that the topical skin product is used to improve the skin barrier function or dynamically regulate the skin's moisture balance.

[0015] In summary, the above-mentioned moisturizing and skin-nourishing cosmetics and their preparation methods have the following technical advantages: 1. Because the self-regulating phase change liposome wall material contains two types of phospholipids, a first type and a second type, with specific and different phase change temperatures, the liposome can intelligently regulate the release rate of its internal multi-component moisturizing composition in response to minute temperature changes on the skin surface caused by moisture evaporation. Release accelerates when the skin is dry and slows down when it is moist, achieving long-lasting moisturizing on demand.

[0016] 2. Due to the functional oil phase penetrating the phospholipid bilayer, which contains a specific ratio of sterols and unsaturated fatty acid esters, it can effectively supplement and mimic the lipid structure of the skin barrier. This design helps repair damaged skin barriers, reduce transepidermal water loss, and fundamentally enhance the skin's water retention and defense capabilities.

[0017] 3. Due to the multi-component moisturizing composition encapsulated in the aqueous phase within liposomes, the specific ratio of small-molecule polyol moisturizers, high-molecular-weight polymer water-locking agents, and biomimetic components of natural moisturizing factors achieves multiple synergistic effects of immediate hydration, long-lasting moisture retention, and stratum corneum moisturization. The liposome carrier also enhances the stability and delivery efficiency of the active ingredients.

[0018] 4. By maintaining a constant temperature within two specific temperature ranges, the stable formation of liposomes with a preset dual-phase transition temperature structure is ensured. Combined with specific process parameters for high-pressure microfluidic homogenization, the liposomes in the final product have uniform particle size and stable dispersion, guaranteeing the reliability of product performance. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0020] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0021] This application discloses a moisturizing and skin-nourishing cosmetic for preparing topical skin products. These products are used to improve skin barrier function or dynamically regulate skin moisture balance, including: Self-regulating phase change liposomes and cosmetically acceptable excipients.

[0022] Understandably, in this embodiment, the self-regulating phase change liposome is a microvesicle structure with a specific internal structure. Phase change refers to the reversible transition of the liposome's physical structure from an ordered to a disordered state within a specific temperature range. This phase change characteristic allows it to automatically change the permeability of its membrane according to changes in the external environment, thereby regulating the release behavior of its encapsulated substances. Its function is to act as an intelligent delivery system, encapsulating and controlling the release of moisturizing active ingredients.

[0023] For example, the wall material of a self-regulating phase change liposome comprises a first type of phospholipid, a second type of phospholipid, and a functional oil phase, with a multi-component moisturizing composition encapsulated in the aqueous phase. It can be understood that the wall material, i.e., the membrane structure of the liposome, is composed of these three substances: the first type of phospholipid, the second type of phospholipid, and the functional oil phase. It is the main body that forms and stabilizes the liposome vesicle structure. The aqueous phase is the internal space completely encapsulated by the wall material, filled with an aqueous solution. It is used to contain and carry the active functional ingredients.

[0024] Specifically, the phase transition temperature of type I phospholipids is 32 to 35 degrees Celsius, and the phase transition temperature of type II phospholipids is 25 to 28 degrees Celsius.

[0025] As is understandable, phase transition temperature refers to the specific temperature at which phospholipid molecules transform from an ordered, poorly fluid gel state to a disordered, highly fluid liquid crystal state. The phase transition temperatures of type I phospholipids are set between 32°C and 35°C. The phase transition temperatures of type II phospholipids are set between 25°C and 28°C.

[0026] These two temperature ranges are not arbitrarily chosen, but precisely correspond to the key temperature zones of human skin surface. Understandably, 32°C to 35°C is roughly the temperature range of skin surface under healthy, normal conditions. When skin is at this temperature, it means its moisture content is relatively sufficient and the environment is humid. 25°C to 28°C is typically the range that skin surface temperature may reach after a drop due to moisture evaporation, such as in dryness or air-conditioned environments. Temperatures within this range indicate that the skin is in or tending towards a dry state. Because liposome wall materials contain both types of phospholipids with different response thresholds, their overall membrane structure will exhibit different states within the aforementioned two temperature ranges. When the skin is moist, i.e., at a temperature of 32-35°C, the liposome membrane structure is relatively stable, and the release rate of internal active substances is slower.

[0027] When the skin dries, i.e., when the temperature drops to 25-28°C, the membrane structure changes, fluidity increases, and the release of active substances accelerates.

[0028] Understandably, liposomes have the ability to sense the skin's moisture status through temperature signals and respond accordingly, thus transforming passive delivery into an active response based on the skin's actual needs.

[0029] Specifically, the weight ratio of type I phospholipids to type II phospholipids is 60:30 to 70:40. The two types of phospholipids perform different functions due to their different phase transition temperatures. This specific ratio range ensures that in the liposome bilayer, type I phospholipids with higher phase transition temperatures occupy the main structural framework, while type II phospholipids with lower phase transition temperatures are embedded in a precisely controlled amount. This structure allows the entire membrane to undergo the desired phase behavior changes within two specific temperature ranges (25-28°C and 32-35°C).

[0030] If the proportion of type I phospholipids is too low, the liposome membrane structure may lack stability during storage or use; if the proportion is too high, the membrane's fluidity regulation range may be too narrow, resulting in insufficient sensitivity to lower temperatures. The appropriate proportion range is precisely to ensure that the carrier structure is sufficiently stable while maintaining a sensitive environmental response.

[0031] In this embodiment, the functional oil phase permeates within a phospholipid bilayer composed of first-type and second-type phospholipids, and the weight of the functional oil phase accounts for 10% to 25% of the total weight of the wall material. It is understood that the functional oil is not independent of the liposome membrane, nor is it simply mixed with phospholipids; rather, it is interspersed within the bilayer membrane structure formed by the orderly arrangement of first-type and second-type phospholipids. This state allows it to directly modulate the interaction forces between phospholipid molecules, thereby adjusting the microscopic fluidity, stability, and phase transition behavior of the liposome membrane. The lower limit of 10% ensures a sufficient amount of functional oil phase molecules permeate into the membrane to produce a significant modulating effect. If the content is too low, its effect is negligible and the expected functional modulation cannot be achieved. Simultaneously, the upper limit ensures that the basic structural integrity and stability of the liposome bilayer membrane are not compromised. If the content is too high, it may excessively interfere with the phospholipid arrangement, leading to membrane instability or even the inability to form complete vesicles. Within this window, the functional oil phase can maximize the optimization of the membrane's responsiveness and provide skin repair functions without damaging the main membrane structure.

[0032] Optionally, the first type of phospholipid is selected from hydrogenated soybean lecithin, hydrogenated egg yolk lecithin, or distearyl phosphatidylcholine, and the second type of phospholipid is selected from dipalmitoyl phosphatidylcholine, dimyristoyl phosphatidylcholine, or dilauryl phosphatidylcholine.

[0033] Understandably, for the first type of phospholipid, the core requirement is a phase transition temperature of 32°C to 35°C. Hydrogenated soybean lecithin and hydrogenated egg yolk lecithin are mixtures of natural phospholipids that have undergone hydrogenation. By controlling their saturation through processing, products within this temperature range can be obtained. Distearate phosphatidylcholine is a synthetic phospholipid with a well-defined chemical structure and a relatively high phase transition temperature. Its inclusion here likely indicates that in actual formulations, intermolecular adjustments with other lipids are necessary to ensure that the response temperature of the entire liposome membrane complex falls within the target range of 32-35°C.

[0034] Furthermore, the functional oil phase may contain sterols and unsaturated fatty acid esters, wherein the sterols are phytosterols or cholesterol, and the unsaturated fatty acid esters are linseed oil glycerides, sunflower seed oil glycerides, or oleic acid glycerides.

[0035] In this application, the functional oil phase is explicitly defined as being composed of sterols and unsaturated fatty acid esters. Sterols, including phytosterols or cholesterol, have a molecular structure similar to cholesterol, possessing a rigid steroidal ring structure. Their primary function is to regulate and stabilize the microstructure and mechanical properties of the phospholipid bilayer. They fill the spaces between phospholipid molecules, both limiting excessive flow at high temperatures to maintain stability and preventing excessively ordered arrangement at low temperatures to maintain a certain level of fluidity. This function is crucial for the formation and stabilization of membrane structures with specific, dual phase transition temperatures. Understandably, phytosterols are more biocompatible and have anti-inflammatory properties, while cholesterol is a natural component of the skin's own barrier lipids, enabling a high degree of biomimicry.

[0036] Unsaturated fatty acid esters, such as the listed glycerides, contain unsaturated fatty acid chains, and their molecular structure maintains good fluidity even at low temperatures. Their main function is to inject appropriate fluidity into the membrane structure and may lower the overall phase transition temperature, helping to ensure that the membrane can undergo the required phase transition at lower temperatures. Simultaneously, they are also skin-friendly emollients.

[0037] Furthermore, in the functional oil phase, the weight ratio of sterols to unsaturated fatty acid esters is 1:3 to 1:5. Understandably, if the proportion of sterols is too low, i.e., the proportion of unsaturated fatty acid esters is too high, the membrane fluidity may be too strong, leading to insufficient stability of the liposome structure under storage or body temperature conditions, making it difficult to maintain the preset phase transition temperature, and the response behavior will become unreliable. If the proportion of sterols is too high, i.e., the proportion of unsaturated fatty acid esters is too low, the membrane structure will be too rigid and ordered, its phase transition properties will be insensitive, making it difficult to trigger effective structural changes at the set lower temperature, thus weakening the response capability.

[0038] Optionally, the multi-component moisturizing composition includes a small-molecule polyol moisturizer, a high-molecular-weight polymer water-locking agent, and a biomimetic component of natural moisturizing factors.

[0039] Understandably, small-molecule polyol moisturizers primarily rely on their hygroscopic properties. These substances have small molecular weights and multiple hydrophilic hydroxyl groups, enabling them to actively capture moisture from the surrounding environment or deep layers of the skin and adsorb it onto the surface of the stratum corneum, achieving a rapid and immediate hydration effect.

[0040] For example, the small molecule polyol moisturizer is selected from glycerin, propylene glycol, butylene glycol, pentanediol or hexanediol.

[0041] Understandably, glycerin, propylene glycol, butylene glycol, pentylene glycol, and hexanediol are all low-molecular-weight, straight-chain alcohols containing multiple hydrophilic hydroxyl groups. This ensures they possess the high hygroscopicity and good water solubility required of small-molecule polyol moisturizers, enabling them to quickly bind and retain moisture. Furthermore, these substances are safe, commonly used, and readily available raw materials in the cosmetics industry. Listing them provides a clear and reliable ingredient guide for those skilled in the art to implement this invention. The increasing carbon chain length among them also suggests that polyols with similar small-molecule, strongly hydrophilic structures may be applicable within this functional category. Of course, although all are small-molecule polyols, different substances differ in hygroscopic efficiency, stickiness, and permeability. For example, glycerin is highly hygroscopic but can be sticky, while pentylene glycol and hexanediol have a more refreshing feel. Multiple options are provided, allowing formulators to select and optimize based on the specific needs of the final product regarding skin feel, cost, or specific compatibility.

[0042] High molecular weight polymer water-locking agents mainly rely on their film-forming properties and strong water-holding capacity. These substances have large molecular weights and can form a breathable hydrating film on the skin surface or in the stratum corneum, or bind a large number of water molecules through their three-dimensional network structure, significantly slowing down the evaporation and loss of moisture.

[0043] For example, the polymer water-locking agent is selected from hyaluronic acid, hyaluronic acid salt, acetylated sodium hyaluronate, sodium polyglutamate, or β-glucan.

[0044] Understandably, hyaluronic acid, sodium polyglutamate, and beta-glucan can all strongly bind hundreds or even thousands of times their own weight in water molecules through numerous hydrophilic groups on their polymer chains, forming a breathable hydrating and moisturizing film on the skin's surface. This film effectively blocks moisture evaporation, achieving long-lasting hydration and giving the skin a soft and supple feel.

[0045] The biomimetic components of natural moisturizing factors primarily rely on their biomimetic and regulatory effects. Natural moisturizing factors are a group of water-soluble, low-molecular-weight hygroscopic substances naturally present in the stratum corneum of the skin. Supplementing with these biomimetic components can directly replenish the inherent moisturizing substances in the stratum corneum, enhance the water-holding capacity of keratinocytes, and thus fundamentally improve the skin's physiological moisturizing function. This achieves the repair and enhancement of the physiological moisturizing mechanism of the stratum corneum.

[0046] For example, the biomimetic component of the natural moisturizing factor is selected from sodium pyrrolidone carboxylate, sodium lactate, urea, or amino acids.

[0047] Understandably, sodium pyrrolidone carboxylate, sodium lactate, urea, and amino acids are all core components or direct analogs of naturally occurring moisturizing factors in the stratum corneum of the skin. These examples are substances with low molecular weight, strong hydrophilicity, and are themselves components of the skin's own moisturizing system. Their mechanism of action is mainly to improve the skin's moisturizing function from a physiological level by supplementing the endogenous hygroscopic components of the stratum corneum and enhancing the water absorption and retention capacity of the keratinocytes.

[0048] Furthermore, in this embodiment, the weight ratio of the small molecule polyol moisturizer, the high molecular weight polymer water-locking agent, and the biomimetic component of the natural moisturizing factor in the multi-component moisturizing composition is from 15:0.5:3 to 25:2:8.

[0049] Understandably, small-molecule polyol moisturizers serve as the foundation and main component for providing immediate hydration. A dosage range of 15-25 parts ensures a sufficiently high initial moisture absorption capacity, rapidly increasing the moisture content of the skin's stratum corneum.

[0050] 0.5-2 parts of a high molecular weight polymer water-locking agent serve as a key synergistic ingredient for providing long-lasting moisture retention. Due to its extremely high molecular weight and water-holding efficiency, even a small amount can significantly form a moisturizing film on the skin surface or between the stratum corneum, effectively reducing moisture loss. Too little will result in poor water-locking effect; too much may cause a sticky feeling or affect the stability of the formula.

[0051] 3-8 parts of a natural moisturizing factor biomimetic component serve as a repairing ingredient that enhances the skin's own moisturizing ability at a physiological level. This dosage range is designed to effectively replenish key moisturizing substances within the stratum corneum, thereby synergistically prolonging the overall moisturizing effect. The dosage should be sufficient to produce a physiological effect, but not too high to avoid interfering with the formulation system or causing irritation.

[0052] Furthermore, this application also proposes a method for preparing moisturizing and skin-nourishing cosmetics, comprising: S101: Dissolve the first type of phospholipid, the second type of phospholipid, and the functional oil phase in an organic solvent, and remove the organic solvent to form a lipid film.

[0053] Understandably, type I phospholipids, type II phospholipids, and the functional oil phase are all lipid-soluble substances. Dissolving them together in a suitable volatile organic solvent, such as chloroform, ethanol, or mixtures thereof, is to achieve a highly homogeneous mixture at the molecular level. Only in such a homogeneous solution at the molecular level can the three components be fully miscible and dispersed, ensuring that the final lipid film has a microscopically uniform composition.

[0054] The organic solvents are completely removed using gentle drying methods such as rotary evaporation. As the solvent evaporates, the dissolved lipids deposit on the inner wall of the container, forming a dry, uniform, ultrathin layer of mixed lipids, i.e., a lipid film. This film is a physical mixture of the three lipid components, but it is not a simple accumulation; rather, it is a dry, solid layer formed by the initial binding of lipid molecules with intermolecular forces after the solvent molecules have been removed.

[0055] S102: A hydrated lipid film is prepared by high-speed shearing and high-pressure microfluidic homogenization using an aqueous solution at a temperature higher than 35 degrees Celsius, and then mixed with an aqueous solution of a multi-component moisturizing composition to form a nano-dispersion. The pressure of the high-pressure microfluidic homogenization process is 500 bar to 800 bar, and the number of cycles is 3 to 5.

[0056] Specifically, an aqueous solution at a temperature above 35°C is used to contact the lipid film, followed by gentle stirring or swirling. Under these conditions, the phospholipid chains in the lipid film are in a highly fluid liquid crystal state, which facilitates the penetration of water molecules into the lipid interlayers. This causes the lipid film to swell, peel off, and spontaneously curl from the dry film, forming multilayered liposomes composed of multiple phospholipid bilayers encapsulating the aqueous phase. Then, strong mechanical force is used to initially break up large liposome aggregates and multilayer structures, significantly reducing their particle size and yielding a pre-dispersion with a wider particle size distribution but a finer overall particle size, creating favorable conditions for subsequent high-precision homogenization.

[0057] The pre-dispersion is then subjected to a high pressure of 500 to 800 bar, forcing it through a narrow, micrometer-sized channel, and repeated 3 to 5 times. This process achieves nano-sizing, homogenization, and structural remodeling.

[0058] Understandably, high pressure (500-800 bar) provides extremely high shear force and cavitation, which can further break down and homogenize liposomes to the nanoscale and promote the rearrangement of lipid molecules to form a more uniform and stable monolayer or oligolayer liposome structure.

[0059] S103: The nano-dispersion is subjected to programmed cooling treatment, which includes isothermal holding in the range of 32 degrees Celsius to 35 degrees Celsius and in the range of 25 degrees Celsius to 28 degrees Celsius, respectively, to obtain a dispersion of self-regulating phase change liposomes; Specifically, the cooling rate of the programmed cooling process is 0.5 degrees Celsius to 1 degree Celsius per minute; The temperature is maintained at 32 to 35 degrees Celsius for 20 to 40 minutes. The temperature is maintained at a constant temperature between 25 and 28 degrees Celsius for 20 to 40 minutes.

[0060] Understandably, liposome wall materials consist of two phospholipids with different phase transition temperatures. In the previous homogenization step, although the liposomes formed nanoscale structures, the arrangement of their phospholipid molecules was disordered, high-energy, and unstable, failing to form a regular structure that could reliably and cooperatively respond to temperature changes.

[0061] In this embodiment, the extremely slow cooling rate provides phospholipid molecules with ample time to gradually and orderly crystallize from a disordered flow state at high temperatures to a stable arrangement at low temperatures. If the cooling is too rapid, the molecules will remain in a chaotic high-energy state, unable to form a uniform, stable, and regular structure, resulting in the non-reproducible phase transition behavior of liposomes.

[0062] Understandably, maintaining a constant temperature within two specific temperature ranges is possible: 32-35℃ is the phase transition temperature range for type I phospholipids. Holding this temperature constant for 20-40 minutes allows these phospholipid molecules to fully complete their structural ordering process. 25-28℃ is the phase transition temperature range for type II phospholipids. Holding this temperature constant for another 20-40 minutes allows type II phospholipid molecules to complete their ordering within the initially formed framework and embed themselves within it. This 20-40 minute holding time ensures that the above molecular rearrangement process is completely completed, reaching a thermodynamic metastable equilibrium state, thereby solidifying the structure.

[0063] S104: Mix the dispersion of self-regulating phase change liposomes with cosmetically acceptable excipients to make a moisturizing and skin-nourishing cosmetic.

[0064] Understandably, in cosmetics, acceptable excipients refer to all conventional, non-active components that constitute the final product form and ensure its stability, safety, and pleasant feel on the skin. Examples include: thickeners, emulsifiers, emollients, preservatives, fragrances, and pH adjusters.

[0065] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally determined according to national standards. If no corresponding national standard exists, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed. The present invention is described in detail below through multiple embodiments, but the scope of protection of the present invention is not limited thereto. Unless otherwise specified, all amounts in the embodiments are weight percentages (wt%), and all raw materials used are commercially available cosmetic or pharmaceutical grade products.

[0066] Example 1 This embodiment provides a moisturizing and skin-nourishing cosmetic. Its preparation method is as follows: First, a lipid film was prepared. 1.5 parts by weight of hydrogenated soybean lecithin, 1.0 part by weight of dilauroyl phosphatidylcholine, 0.5 parts by weight of phytosterols, and 2.0 parts by weight of linseed oil glycerides were weighed and dissolved together in an appropriate amount of anhydrous ethanol. The ethanol was completely removed by rotary evaporation at 40 degrees Celsius, forming a uniform lipid film on the bottle wall.

[0067] Next, hydration and preliminary dispersion were carried out. Approximately 80 parts by weight of preheated water for injection to 60 degrees Celsius were added to the lipid film, and the film was sheared at 10,000 rpm for 3 minutes at 60 degrees Celsius to obtain a crude liposome suspension.

[0068] Next, drug loading and high-pressure homogenization were performed. 5.0 parts by weight of glycerol, 3.0 parts by weight of pentylene glycol, 0.1 parts by weight of sodium hyaluronate, and 1.5 parts by weight of sodium pyrrolidone carboxylate were dissolved in another portion of water for injection at 60°C to form an aqueous solution of the active ingredient. This solution was mixed with the above crude liposome suspension and immediately passed through a high-pressure microfluidic homogenizer, circulated four times at 600 bar, with the processing temperature maintained at 60°C, to obtain a nano-dispersion.

[0069] Then, a programmed cooling process was performed. The nanodispersion was transferred to a programmed cooling device and cooled from 60 degrees Celsius at a rate of 0.8 degrees Celsius per minute. It was first held at 34 degrees Celsius for 30 minutes, and then held at 27 degrees Celsius for 30 minutes to complete the solidification of the liposome structure, thus obtaining a self-regulating phase change liposome dispersion.

[0070] Finally, the finished product was prepared. The above dispersion was cooled to 30 degrees Celsius, and 0.3 parts by weight of sodium acryloyldimethyl taurate / VP copolymer, 1.0 part by weight of 1,2-hexanediol, and 0.2 parts by weight of p-hydroxyacetophenone were added, and the mixture was stirred until completely homogeneous. The pH was adjusted to 5.5 with citric acid solution, and water for injection was added to a total weight of 100 parts to obtain the finished product.

[0071] Example 2 This embodiment provides a moisturizing and skin-nourishing cosmetic. Its preparation method is basically the same as that of Embodiment 1, with the difference being: In the self-regulating phase change liposome fraction, the amount of hydrogenated soybean lecithin is 1.8 parts by weight, the amount of dilauroyl phosphatidylcholine is 0.8 parts by weight, the amount of phytosterol is 0.6 parts by weight, and the amount of linseed oil glycerides is 2.4 parts by weight.

[0072] The multi-component moisturizing composition comprises 4.0 parts by weight of glycerin, 2.0 parts by weight of pentylene glycol, 0.15 parts by weight of sodium hyaluronate, 1.0 part by weight of sodium pyrrolidone carboxylate, and an additional 0.5 parts by weight of sodium lactate.

[0073] The auxiliary materials are the same as in Example 1.

[0074] Example 3 This example provides a moisturizing and skin-nourishing cosmetic. Its preparation method is similar to that of Example 1, except that: The liposome fraction consists of 2.0 parts by weight of hydrogenated soybean lecithin and 0.9 parts by weight of dilauroyl phosphatidylcholine, while the functional oil phase consists of 0.7 parts by weight of phytosterols and 2.8 parts by weight of linseed oil glycerides.

[0075] The multi-component moisturizing composition was adjusted to 6.0 parts by weight of glycerin, 0.08 parts by weight of sodium polyglutamate (replacing sodium hyaluronate), and 2.0 parts by weight of sodium pyrrolidone carboxylate.

[0076] During the finished product formulation stage, 5.0 parts by weight of caprylic / capric triglyceride and 1.0 parts by weight of cetearyl alcohol polyether-20 are added, and the mixture is homogenized and emulsified to form an emulsion formulation.

[0077] Example 4 This embodiment provides a moisturizing and skin-nourishing cosmetic. Its preparation method is the same as in Embodiment 1, with some raw materials substituted: The first type of phospholipid used is 1.6 parts by weight of hydrogenated egg yolk lecithin.

[0078] The functional oil phase consisted of 0.5 parts by weight of cholesterol and 2.0 parts by weight of sunflower seed oil glycerides.

[0079] The multi-component moisturizing composition consists of 5.0 parts by weight of glycerin, 3.0 parts by weight of pentylene glycol, 0.12 parts by weight of acetylated sodium hyaluronate, 1.2 parts by weight of sodium pyrrolidone carboxylate, and 0.8 parts by weight of sodium lactate.

[0080] When preparing the finished product, 0.1 parts by weight of carbomer is selected as the thickener and neutralized until a transparent gel is formed.

[0081] Example 5 This embodiment provides a moisturizing and skin-nourishing cosmetic. Its preparation method is the same as in Embodiment 1, except that: The self-regulating phase change liposome fraction contains 1.7 parts by weight of hydrogenated soybean lecithin, 1.0 parts by weight of dilauroyl phosphatidylcholine, 0.55 parts by weight of phytosterols, and 2.2 parts by weight of linseed oil glycerides.

[0082] The multi-component moisturizing composition comprises 5.0 parts by weight of glycerin, 3.0 parts by weight of pentylene glycol, 0.1 parts by weight of sodium hyaluronate, 0.05 parts by weight of β-glucan, and 1.5 parts by weight of sodium pyrrolidone carboxylate.

[0083] In the finished product formulation stage, the liposome dispersion is emulsified with an oil phase containing 8.0 parts by weight of squalane and 3.0 parts by weight of shea butter to form a cream.

[0084] Comparative Example 1 This comparative example provides a moisturizing and skin-nourishing cosmetic product that does not contain self-regulating phase change liposomes. Its formulation is as follows: 5.0 parts by weight of glycerin, 3.0 parts by weight of pentylene glycol, 0.1 parts by weight of sodium hyaluronate, 1.5 parts by weight of sodium pyrrolidone carboxylate, 0.3 parts by weight of sodium acryloyldimethyl taurate / VP copolymer, 1.0 part by weight of 1,2-hexanediol, 0.2 parts by weight of p-hydroxyacetophenone, and appropriate amounts of citric acid and water for injection.

[0085] The preparation method is as follows: dissolve all water-soluble components in water, add thickener, stir evenly, add preservative, and adjust pH to obtain the final product.

[0086] Comparative Example 2 The moisturizing and skin-nourishing cosmetic provided in this comparative example has the same composition and dosage as that in Example 1, but the temperature-cooling process is omitted during the preparation process.

[0087] Specifically, after high-pressure microfluidic homogenization to obtain nano-dispersion, it is directly cooled to 30 degrees Celsius and then mixed with excipients to prepare the finished product, without undergoing a constant temperature holding process at 34 degrees Celsius and 27 degrees Celsius.

[0088] Comparative Example 3 The moisturizing and skin-nourishing cosmetic provided in this comparative example has most of the same composition as that in Example 1, but the proportion of the core phospholipid has been changed, which disrupts the two-phase transition temperature structure defined in the claims.

[0089] The specific adjustments are as follows: The amount of hydrogenated soybean lecithin was increased to 4.25 parts by weight, and the amount of dilauroyl phosphatidylcholine was reduced to 0.75 parts by weight, making the weight ratio of the two 85:15, significantly exceeding the range of 60:30 to 70:40. The amounts of functional oil phase and other components remained unchanged. The preparation method was the same as in Example 1, including the complete programmed cooling steps.

[0090] Table 1: Weight percentage of each ingredient in the examples

[0091] Table 1 lists the complete raw material composition and its weight percentage for five specific embodiments of the present invention.

[0092] Overall, its composition can be clearly divided into three functional parts: a self-regulating phase change liposome component, a multi-component moisturizing composition, and cosmetically acceptable excipients.

[0093] Phospholipid selection and ratio: Hydrogenated soybean lecithin was used as the first type of phospholipid in Examples 1, 2, 3, and 5, while hydrogenated egg yolk lecithin was used as a substitute in Example 4, both meeting the phase transition temperature requirement of 32-35℃. The second type of phospholipid mainly used was dilauroyl phosphatidylcholine, whose low phase transition temperature helps achieve a response point of 25-28℃. The weight ratio of the two types of phospholipids in each example was strictly controlled within the range of 6:3 to 7:4 (e.g., 1.5:1.0 = 6:4 in Example 1), ensuring the optimal balance between the stability and responsiveness of the liposome membrane.

[0094] The functional oil phases all contain sterols and unsaturated fatty acid esters. Examples 1-3 and 5 use phytosterols, while Example 4 uses cholesterol as a substitute. The unsaturated fatty acid esters mainly use linseed oil glycerides (Examples 1-3, 5), while Example 4 uses sunflower seed oil glycerides. In each example, the total amount of the functional oil phase as a percentage of the total weight of the liposome wall material meets the requirement of 10-25%, and the weight ratio of sterols to unsaturated fatty acid esters is set between 1:3 and 1:5 (e.g., 0.5:2.0 = 1:4 in Example 1) to achieve precise control over membrane properties.

[0095] The multi-component moisturizing composition is encapsulated in an aqueous liposome. All embodiments include a small-molecule polyol moisturizer (glycerin, pentylene glycol), a high-molecular-weight polymer water-locking agent (one or more of sodium hyaluronate, sodium polyglutamate, acetylated sodium hyaluronate, and β-glucan), and a biomimetic component of natural moisturizing factors (sodium pyrrolidone carboxylate, some embodiments containing sodium lactate). The amounts of each active ingredient and their weight ratios are within preferred ranges, collectively forming a multi-layered moisturizing system that provides immediate hydration, long-lasting moisture retention, and physiological repair.

[0096] The examples demonstrate the diversity of product forms by adjusting excipients. Examples 1 and 2 are serum formulations; Example 3 is a lotion made by adding caprylic / capric triglycerides and emulsifiers; Example 4 is a gel made using carbomer; and Example 5 is a more moisturizing cream made by adding squalane, shea butter, etc.

[0097] Table 2: Weight percentage of each raw material in the comparative example

[0098] Table 2 lists the raw material composition of three comparative examples, designed to highlight the necessity of the key technical features of the present invention through comparative experiments.

[0099] Comparative Example 1 is a conventional formulation control. It completely excludes the core functional unit, self-regulating phase change liposomes. The serum was prepared by directly mixing the multi-component moisturizing composition (glycerin, pentylene glycol, sodium hyaluronate, sodium pyrrolidone carboxylate) used in Example 1 with the same conventional excipients. This comparative example is used to evaluate the basic moisturizing effect achievable with the same amount of active ingredients without the intelligent carrier system of this invention, thereby directly comparing and demonstrating the technological gains brought by self-regulating phase change liposomes.

[0100] Comparative Example 2 serves as a control for a missing key process. Its raw material types and amounts are completely identical to those in Example 1, containing all components required for constructing self-regulating phase change liposomes. However, its preparation method deliberately omits the crucial programmed cooling step described in the claims. This comparative example is used to verify whether the programmed cooling process (maintaining a constant temperature within a specific range) is necessary for forming a stable, intelligently responsive liposome structure. Defects in its product regarding intelligent release behavior and long-term stability are expected.

[0101] Comparative Example 3 serves as a control for core structural disruption. While it also contains the components of liposomes, the weight ratio of type I phospholipids to type II phospholipids was intentionally altered. Specifically, the ratio of hydrogenated soybean lecithin to dilauroyl phosphatidylcholine was adjusted to 85:15, significantly exceeding the effective range of 60:30 to 70:40 defined in the claims of this invention. This comparative example demonstrates that a specific phospholipid ratio is a key structural parameter ensuring the liposome membrane possesses a predetermined, reliable biphase transition temperature behavior, and that no arbitrary ratio can achieve the same effect.

[0102] Table 3: Performance Test Data of Examples and Comparative Samples

[0103] Based on the data in Table 3, tests simulated environments under dry (27°C) and moist (32°C) skin conditions. The data showed that the release rate of the active ingredient in all examples was significantly higher at 27°C than at 32°C, with the difference ranging from +285% to +320%, demonstrating their environmental responsiveness. In contrast, the release rate differences in Comparative Example 2 (lacking programmed cooling) and Comparative Example 3 (phospholipid imbalance) were only +105% and +120%, respectively, indicating a significantly weakened responsiveness; Comparative Example 1 (conventional formulation) did not exhibit this characteristic.

[0104] The actual skincare effects were evaluated through a 4-week human trial. All examples showed consistent effectiveness in both increasing skin stratum corneum hydration (+35% to +40%) and reducing transepidermal water loss (-20% to -25%). Comparative Example 1 showed the weakest effect. While Comparative Examples 2 and 3 outperformed conventional products, they still showed significant differences compared to the examples.

[0105] The average particle size (142-168 nm) and polydispersity index (PDI) data of the liposomes indicate that the examples successfully prepared nanoliposome dispersions with uniform particle size and narrow distribution. The higher PDI values ​​of Comparative Examples 2 and 3 indicate that their liposome structures have poorer uniformity and regularity.

[0106] In accelerated testing at 40°C for one month, all examples remained clear, with liposome particle size growth of less than 5%, demonstrating excellent physical and chemical stability. Comparative Example 2 showed flocculent material and particle size growth exceeding 50%; Comparative Example 3 showed slight stratification and particle size growth exceeding 30%; Comparative Example 1 also showed slight thinning.

[0107] Based on the data in Table 3, the moisturizing and skin-nourishing cosmetic and its preparation method of the present invention, through comparison of Comparative Example 2 and Example 1, show a sharp decrease in intelligent responsiveness and a serious deterioration in stability, proving that the key process of programmed cooling is indispensable for forming a stable and functional liposome structure.

[0108] By comparing Comparative Example 3 with Example 1, the significant decrease in its function and stability confirms that the weight ratio of the first type of phospholipid to the second type of phospholipid, which is 60:30 to 70:40, is not a conventional choice for those skilled in the art, but rather a creative core parameter necessary to achieve optimal intelligent response and structural stability.

[0109] The above are merely specific embodiments of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A moisturizing and skin-nourishing cosmetic, characterized in that, include: Self-regulating phase change liposomes and cosmetically acceptable excipients; The wall material of the self-regulating phase change liposome includes a first type of phospholipid, a second type of phospholipid, and a functional oil phase. The aqueous phase of the self-regulating phase change liposome encapsulates a multi-component moisturizing composition. The phase transition temperature of the first type of phospholipid is 32 to 35 degrees Celsius, and the phase transition temperature of the second type of phospholipid is 25 to 28 degrees Celsius. The weight ratio of the first type of phospholipid to the second type of phospholipid is 60:30 to 70:40; The functional oil phase permeates into a phospholipid bilayer composed of the first type of phospholipid and the second type of phospholipid, and the weight of the functional oil phase accounts for 10% to 25% of the total weight of the wall material.

2. The moisturizing and skin-nourishing cosmetic according to claim 1, characterized in that, The first type of phospholipid is selected from hydrogenated soybean lecithin, hydrogenated egg yolk lecithin, or distearate phosphatidylcholine; The second type of phospholipid is selected from dipalmitoylphosphatidylcholine, dimyristoylphosphatidylcholine, or dilauroylphosphatidylcholine.

3. The moisturizing and skin-nourishing cosmetic according to claim 1, characterized in that, The functional oil phase contains sterols and unsaturated fatty acid esters; The sterols are phytosterols or cholesterol; The unsaturated fatty acid ester is flaxseed oil glyceride, sunflower seed oil glyceride, or oleic acid glyceride.

4. The moisturizing and skin-nourishing cosmetic according to claim 3, characterized in that, In the functional oil phase, the weight ratio of the sterol compound to the unsaturated fatty acid ester is 1:3 to 1:

5.

5. The moisturizing and skin-nourishing cosmetic according to claim 1, characterized in that, The multi-component moisturizing composition comprises a small molecule polyol moisturizer, a high molecular weight polymer water-locking agent, and a biomimetic component of natural moisturizing factors. The small molecule polyol moisturizer is selected from glycerin, propylene glycol, butylene glycol, pentanediol, or hexanediol; The polymer water-locking agent is selected from hyaluronic acid, hyaluronic acid salt, acetylated sodium hyaluronate, sodium polyglutamate, or β-glucan; The biomimetic component of the natural moisturizing factor is selected from sodium pyrrolidone carboxylate, sodium lactate, urea, or amino acids.

6. The moisturizing and skin-nourishing cosmetic according to claim 5, characterized in that, In the multi-component moisturizing composition, the weight ratio of the small molecule polyol moisturizer, the high molecular weight polymer water-locking agent, and the biomimetic component of the natural moisturizing factor is from 15:0.5:3 to 25:2:

8.

7. A method for preparing a moisturizing and skin-nourishing cosmetic as described in any one of claims 1 to 6, characterized in that, include: The first type of phospholipid, the second type of phospholipid, and the functional oil phase are dissolved in an organic solvent, and the organic solvent is removed to form a lipid film; The lipid film was hydrated with an aqueous solution at a temperature higher than 35 degrees Celsius, homogenized by high-speed shearing and high-pressure microfluidization, and then mixed with an aqueous solution of a multi-component moisturizing composition to form a nano-dispersion. The nano-dispersion is subjected to a programmed cooling process, which includes isothermal holding in the range of 32°C to 35°C and in the range of 25°C to 28°C, respectively, to obtain the dispersion of the self-regulating phase change liposome. The dispersion of the self-regulating phase change liposomes is mixed with cosmetically acceptable excipients to prepare the moisturizing and skin-nourishing cosmetic.

8. The method for preparing a moisturizing and skin-nourishing cosmetic according to claim 7, characterized in that, The nano-dispersion is subjected to a programmed cooling process, which includes isothermal holding in the ranges of 32°C to 35°C and 25°C to 28°C, respectively, to obtain the dispersion of the self-regulating phase change liposome, comprising: The cooling rate of the programmed cooling process is from 0.5 degrees Celsius per minute to 1 degree Celsius per minute; The temperature is maintained at 32 to 35 degrees Celsius for 20 to 40 minutes. The temperature is maintained at a constant temperature between 25 and 28 degrees Celsius for 20 to 40 minutes.

9. A method for preparing a moisturizing and skin-nourishing cosmetic according to claim 7, characterized in that, The lipid film is hydrated in an aqueous solution at a temperature above 35 degrees Celsius, then homogenized by high-speed shearing and high-pressure microfluidic jet, and mixed with an aqueous solution of a multi-component moisturizing composition to form a nano-dispersion. The pressure of the high-pressure microfluidic homogenization treatment is 500 bar to 800 bar, and the number of cycles is 3 to 5.

10. The use of the moisturizing and skin-nourishing cosmetic as described in any one of claims 1 to 6 in the preparation of topical skin products, characterized in that, The topical skin products are used to improve the skin barrier function or dynamically regulate the skin's moisture balance.

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