A supramolecular micellar composition for reducing the irritancy of 4-butylresorcinol

Abstract

The present application provides a kind of reducing 4-butyl resorcinol irritability supramolecular micelle composition, belong to medical, dental or cosmetic formulation field.The composition includes 4-butyl resorcinol, lipophilic amino acid derivative, amphiphilic block polymer and phosphatidylcholine modified polymer and optional pterostilbene;Composition includes inner core layer, polymer coating layer and functionalized outer layer in turn from inside to outside.The present application utilizes lipophilic amino acid derivative and 4-butyl resorcinol to construct complex active core to reduce the concentration of free active molecule, then utilizes amphiphilic block polymer and phosphatidylcholine modified polymer to carry out space limit and biomimetic interface modification.The present application effectively reduces the skin irritation of 4-butyl resorcinol, improves its chemical stability and slow-release effect, and is suitable for skin care field.

Description

Technical Field

[0001] This invention belongs to the field of medical, dental or cosmetic formulations, and particularly relates to a supramolecular micelle composition that reduces the irritation of 4-butylresorcinol. Background Technology

[0002] 4-Butylresorcinol (4-n-butylresorcinol), as a highly effective tyrosinase inhibitor, can directly block the rate-limiting step in melanin synthesis, exhibiting excellent bioactivity in skin whitening, fading pigmentation, and improving uneven skin tone. With the continuous increase in demand for high-efficacy whitening ingredients in the skin care market, 4-butylresorcinol has become one of the core active ingredients in high-end whitening formulations. However, in its widespread application, the unique physicochemical properties and biological toxicological characteristics of this molecule have also brought significant technical challenges to formulation development. The 4-butylresorcinol molecule contains two highly polar phenolic hydroxyl groups and a flexible aliphatic butyl chain. This lipophilic and hydrophilic structure gives it strong biomembrane penetration ability. When formulations containing high concentrations of 4-butylresorcinol are applied to the skin surface, the free active ingredient easily penetrates the stratum corneum and rapidly diffuses into the deeper layers of the epidermis, leading to a sudden high concentration exposure of active molecules in a localized area within a short period. Such sudden exposure to high concentrations can significantly activate the free nerve endings in the epidermis and the relevant stimulating receptors on keratinocytes, thereby triggering a series of obvious skin nerve stimulation and inflammatory reactions such as stinging, burning, erythema and even allergies, which seriously restricts its safe use and concentration limits in sensitive skin and daily skin care products.

[0003] To reduce the skin irritation caused by 4-butylresorcinol (4-butylresorcinol), the skincare industry currently employs several traditional physical modification and chemical compounding strategies. The most common approach is to directly compound a certain proportion of soothing and anti-allergic active ingredients into the formulation system, such as dipotassium glycyrrhizate, bisabolol, allantoin, centella asiatica extract, or ceramides. This strategy attempts to counteract the skin stinging sensation caused by 4-butylresorcinol by downregulating the expression of inflammatory mediators or repairing the skin's physical barrier through soothing components. However, this simple physical compounding does not change the molecular state of 4-butylresorcinol in the formulation system; it remains dispersed as a highly free molecule in the aqueous or oil phase. When the formulation is applied to the skin, the instantaneous release kinetics of 4-butylresorcinol remain unchanged. The freely diffusing active molecule still preferentially penetrates the stratum corneum with extremely high chemical potential. This makes it difficult for soothing ingredients to completely antagonize the irritation in the early stages, resulting in a very limited effect in reducing irritation. Furthermore, excessive addition of soothing ingredients can significantly increase formulation costs and compatibility risks.

[0004] Another common approach is to introduce carrier encapsulation technology, such as using oil-in-water high-permeability emulsion systems, lecithin liposomes, or conventional microemulsions to physically encapsulate 4-butylresorcinol. These techniques aim to slow down the rate at which the active molecule directly contacts the stratum corneum by encapsulating it in a lipid bilayer or surfactant micelles. However, existing conventional liposomes and microemulsion systems suffer from serious deficiencies in thermodynamic and kinetic stability. Due to 4-butylresorcinol's amphiphilicity and small molecule diffusion capabilities, its partition coefficient between the aqueous and oil / lipid phases is not ideal, resulting in low encapsulation efficiency and a high risk of leakage in conventional liposomes or micelles. During storage, 4-butylresorcinol spontaneously migrates from the carrier to the aqueous phase, reverting to a free state. Upon application to the skin, conventional liposomes are prone to rupture due to surface shear forces and electrolyte conditions, leading to a burst release of the encapsulated active ingredient, failing to address the root cause of the localized instantaneous exposure concentration. In addition, the use of certain highly penetrating emulsifiers can disrupt the tight arrangement of lipids in the stratum corneum, exacerbate the indiscriminate penetration of active ingredients, and even indirectly amplify the irritation response.

[0005] Therefore, how to precisely control the existence state and diffusion behavior of active molecules without destroying the whitening bioactivity and solubility and dispersion properties of 4-butylresorcinol, effectively inhibiting its instantaneous irritation and improving the stability of the system, remains a technical bottleneck that urgently needs to be overcome in the field of skin care efficacy formulations. Summary of the Invention

[0006] The first objective of this invention is to provide a supramolecular micelle composition for reducing the irritation of 4-butylresorcinol, comprising the following components in parts by weight: 4-Butylresorcinol, 0.5-2.0 parts; Lipophilic amino acid derivatives, 1.0-10.0 parts; Amphiphilic block polymer, 5.0-30.0 parts; Phosphatidylcholine modified polymer, 0.5-5.0 parts; The supramolecular micelle composition comprises, from the inside out, a core layer, a polymer coating layer, and a functionalized outer layer. The core layer comprises 4-butylresorcinol and lipophilic amino acid derivatives; The lipophilic amino acid derivative is an amino acid derivative containing a fatty chain structure; The polymer coating layer is formed of an amphiphilic block polymer, which includes hydrophilic blocks and hydrophobic blocks, and the mass ratio of the hydrophilic blocks to the hydrophobic blocks is 1:0.5-1:5. The functionalized outer layer is formed from a phosphatidylcholine-modified polymer.

[0007] Preferably, the lipophilic amino acid derivative is a hydroxyproline derivative modified with a fatty acid chain, wherein the fatty acid chain has 12-16 carbon atoms, and the fatty acid chain is connected to the hydroxyproline backbone by an amide bond or an ester bond.

[0008] Preferably, the number-average molecular weight of the hydrophilic blocks in the amphiphilic block polymer is 500-20000, and the number-average molecular weight of the hydrophobic blocks is 500-30000; the number-average molecular weight of the amphiphilic block polymer is 1000-50000; and the number of carbon atoms in the repeating structural units of the hydrophobic blocks is C6-C24.

[0009] Preferably, after the amphiphilic block polymer forms micelles, the absolute value of the surface potential of the micelles is 5-50mV.

[0010] Preferably, the phosphatidylcholine modified polymer is a modified polymer formed by linking basic polymer segments with phosphatidylcholine structural units, and the mass percentage of the phosphatidylcholine structural units is 10%-50%.

[0011] Preferably, the phosphorus content in the phosphatidylcholine modified polymer is 0.5wt%-5.0wt%.

[0012] Preferably, the number average molecular weight of the base polymer segments of the phosphatidylcholine modified polymer is 2000-90000.

[0013] Preferably, the phosphatidylcholine-modified polymer is prepared by the following method: A water-soluble basic polymer segment containing reactive functional groups is grafted onto an activated phosphatidylcholine derivative to covalently link the phosphatidylcholine structural unit to the side chain or end group of the basic polymer segment. After purification, the phosphatidylcholine-modified polymer is obtained.

[0014] Preferably, the composition further includes pterostilbene, in parts by weight, of 0.1-0.3 parts; the pterostilbene, together with 4-butylresorcinol and a lipophilic amino acid derivative, forms the core layer.

[0015] A second objective of this invention is to provide a method for preparing the aforementioned supramolecular micelle composition with reduced irritation of 4-butylresorcinol, comprising the following steps: Preparation of S1 composite active core: 4-Butylresorcinol, lipophilic amino acid derivatives, and optionally pterostilbene are subjected to co-melting or solvent evaporation treatment to obtain a composite active core. S2 Micelle Formation: The composite active core obtained in step S1 and the amphiphilic block polymer are added to the dispersion medium, and after mixing, dispersion and self-assembly treatment, a micelle dispersion system is obtained; S3 Outer layer modification: Phosphatidylcholine-modified polymer is added to the micelle dispersion system obtained in step S2, and the mixture is then mixed and dispersed to obtain the supramolecular micelle composition.

[0016] This invention constructs a supramolecular micelle system with a multi-layered spatial structure, alters the molecular state of 4-butylresorcinol in the delivery system, and utilizes the synergistic effect of multi-level components to reduce its free state concentration, thereby achieving the goals of reducing irritation, improving stability, and enhancing skin utilization efficiency.

[0017] Specifically, this invention first utilizes 4-butylresorcinol and a lipophilic amino acid derivative to construct a composite active core. The lipophilic amino acid derivative enhances overall hydrophobicity through its fatty chain structure, enabling it to form a compatible microenvironment with 4-butylresorcinol. Simultaneously, the polar interaction sites in the lipophilic amino acid derivative interact with the phenolic hydroxyl groups in the 4-butylresorcinol molecule, transforming 4-butylresorcinol from a highly reactive free molecule to a confined state, thereby reducing its instantaneous release concentration in the system and minimizing the irritation caused by high concentrations of 4-butylresorcinol directly acting on the skin surface. Furthermore, this composite core improves the dispersion stability of 4-butylresorcinol in aqueous systems, mitigating its susceptibility to oxidation and degradation.

[0018] Building upon this foundation, the present invention further utilizes amphiphilic block polymers to construct a polymer coating layer. The amphiphilic block polymer consists of hydrophilic and hydrophobic blocks. The hydrophobic blocks provide a hydrophobic microenvironment matching the composite active core, while the hydrophilic blocks impart excellent water dispersibility to the micelle system. Through the self-assembly of the amphiphilic block polymer, the composite active core is stably confined within the micelle structure, preventing 4-butylresorcinol from being directly exposed to the external aqueous environment. This further reduces the free diffusion rate of the active molecules on a spatial scale, achieving controlled-release regulation.

[0019] Furthermore, this invention introduces a functionalized outer layer formed by a phosphatidylcholine-modified polymer on the outer side of the micelles. The phosphatidylcholine structural units possess hydrophilic interfacial characteristics similar to the phospholipid head groups of cell membranes, which can improve the compatibility between the micelles and the skin interface and reduce the direct irritation between the active ingredient and the skin barrier. Simultaneously, the phosphatidylcholine-modified polymer can improve the spreading properties of the micelles on the skin surface, enabling the micelle system to form a stable interfacial reservoir, which is beneficial for maintaining the sustained release of 4-butylresorcinol at a low concentration.

[0020] When pterostilbene is further added, it can participate in the construction of a complex active core together with 4-butylresorcinol. Pterostilbene has an aromatic hydrophobic structure and phenolic hydroxyl interaction sites, which can enhance the stability of hydrophobic interactions and intermolecular interactions in the core region. At the same time, it exerts an antioxidant synergistic effect, reducing the risk of oxidative inactivation of 4-butylresorcinol during storage and use. This expands the resulting system from a single 4-butylresorcinol delivery system into a complex active delivery system with synergistic whitening and anti-irritation effects.

[0021] Therefore, this invention achieves synergistic regulation of the release behavior, interfacial interaction, and stability of 4-butylresorcinol through a multi-level structural design of "composite active core - polymer coating layer - phosphatidylcholine functionalized outer layer", thereby reducing the risk of irritation while maintaining its whitening activity.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention constructs a composite active core by combining 4-butylresorcinol with lipophilic amino acid derivatives, thereby changing the molecular state of 4-butylresorcinol, reducing the concentration of free 4-butylresorcinol, reducing its instantaneous stimulation to the skin, and improving the tolerance of the system.

[0023] (2) The present invention utilizes amphiphilic block polymers to form a polymer coating layer, which spatially confines the composite active core, improves the dispersion stability of 4-butylresorcinol in the aqueous system, and regulates the release rate of active ingredients to avoid the increased irritation caused by rapid release of active ingredients.

[0024] (3) The present invention introduces phosphatidylcholine-modified polymer into the outer layer of micelles to construct a functionalized outer layer with biomimetic interface characteristics, thereby improving the compatibility between the micelle system and the skin interface, reducing the direct contact between the active components and the skin barrier, and improving the comfort of use.

[0025] (4) The multilayer micelle structure formed by the present invention can simultaneously improve the chemical stability and delivery stability of 4-butylresorcinol, reduce the risk of degradation under environmental conditions such as light and oxidation, and improve the storage stability of the composition.

[0026] (5) When pterostilbene is further introduced, the antioxidant activity of pterostilbene itself and its synergistic effect with 4-butylresorcinol can be utilized to enhance the antioxidant protection of the system and further improve the stability of the active core, so that the composition has the effects of whitening regulation, anti-irritation and stable delivery.

[0027] (6) The present invention uses a multilayer supramolecular micelle structure to deliver 4-butylresorcinol. Compared with the traditional simple compound system, it can not only reduce the risk of irritation of active ingredients, but also achieve continuous release of active ingredients and improve the effective utilization efficiency. It is suitable for skin care products with high requirements for irritation and stability. Attached Figure Description

[0028] Appendix Figure 1 Fourier transform infrared (FR-IR) spectra of the modified polymer PC-PGA-1 prepared in Example 1 and the modified polymer PC-PVA-2 prepared in Example 2.

[0029] Appendix Figure 2 The proton nuclear magnetic resonance spectra of the modified polymer PC-PGA-1 prepared in Example 1 and the modified polymer PC-PVA-2 prepared in Example 2 are shown below. 1 H-NMR).

[0030] Appendix Figure 3 The particle size distribution diagrams of DLS in application examples 1, 4, and 9 are shown. Detailed Implementation

[0031] To better understand the present invention, the present invention will be further described below with reference to specific serial numbers. The terminology used in the serial numbers is for describing specific embodiments and does not constitute a limitation on the scope of protection of the present invention.

[0032] In the specific implementation methods, unless otherwise specified, the experimental methods used are all conventional methods, and the materials and reagents used are all commercially available unless otherwise specified.

[0033] Unless otherwise specified, percentages, etc. in the specific implementation method are assumed to be mass percentages.

[0034] The lipophilic amino acid derivative A used in this invention is N-lauroyl hydroxyproline, whose fatty acid chain structure is C12 lauroyl group, and the lauroyl group is connected to the hydroxyproline skeleton by an amide bond.

[0035] The lipophilic amino acid derivative B used in this invention is N-myristoyl hydroxyproline, whose fatty acid chain structure is C14 myristoyl group, and the myristoyl group is connected to the hydroxyproline backbone by an amide bond.

[0036] The lipophilic amino acid derivative C used in this invention is N-palmitoyl hydroxyproline, whose fatty acid chain structure is C16 palmitoyl group, and the palmitoyl group is connected to the hydroxyproline skeleton by an amide bond.

[0037] The amphiphilic block polymer A used in this invention is polyethylene glycol-polycaprolactone block copolymer (PEG-b-PCL). The number average molecular weight of the hydrophilic polyethylene glycol block in this batch is 4800, the number average molecular weight of the hydrophobic polycaprolactone block is 28600, and the number average molecular weight of the amphiphilic block polymer is 33400.

[0038] The amphiphilic block polymer B used in this invention is polyethylene glycol-polylactic acid block copolymer (PEG-b-PLA). The number average molecular weight of the hydrophilic polyethylene glycol block in this batch is 18,500, the number average molecular weight of the hydrophobic polylactic acid block is 23,800, and the number average molecular weight of the amphiphilic block polymer is 42,300.

[0039] The amphiphilic block polymer C used in this invention is polyethylene glycol-polycaprolactone-polylactic acid block copolymer (PEG-b-PCL-b-PLA). The number-average molecular weight of the hydrophilic blocks in this batch is 6200, the total number-average molecular weight of the hydrophobic blocks is 26700, and the number-average molecular weight of the amphiphilic block polymer is 32900.

[0040] The basic polymer segment A used in this invention is polyγ-glutamic acid, with a number-average molecular weight of 86,000.

[0041] The basic polymer segment B used in this invention is polyvinyl alcohol, with a number-average molecular weight of 1750 and a degree of alcoholysis of 98.0%.

[0042] Example 1: Preparation of phosphatidylcholine-modified polymer (modified polymer PC-PGA-1) The specific steps are as follows: (1) Preparation of activated phosphatidylcholine derivatives Ten parts by mass of glycerol phosphate (GPC) and 12 parts by mass of succinic anhydride were dissolved in 100 parts by volume of dry dimethyl sulfoxide (DMSO). 0.5 parts by mass of 4-dimethylaminopyridine (DMAP) were added, and the reaction was carried out at 60°C under nitrogen protection for 12 h. After the reaction was complete, excess cold acetone was added to precipitate the product. The precipitate was filtered, washed three times with anhydrous ethanol, and dried under vacuum at 40°C for 24 h to obtain a carboxyl-terminated activated phosphatidylcholine derivative.

[0043] (2) Graft copolymerization reaction 90 parts by weight of polyγ-glutamic acid were fully dissolved in 500 parts by volume of anhydrous DMSO, and 8.5 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC·HCl) and 5.1 parts by weight of N-hydroxysuccinimide (NHS) were added. The mixture was then activated and stirred at 25°C for 2 hours.

[0044] Subsequently, 12.5 parts by mass of the activated phosphatidylcholine derivative obtained in step (1) above was dissolved in 100 parts by volume of DMSO and slowly added dropwise to the above polyγ-glutamic acid solution. After the addition was completed, the mixture was heated to 50°C and reacted for 24 hours.

[0045] (3) Purification and drying After the reaction mixture was cooled to room temperature, it was poured into 3500 parts by volume of anhydrous ethanol to initiate precipitation. The precipitate was redissolved in a small amount of distilled water and placed in a dialysis bag with a molecular weight cutoff of 10000 Da. Dialysis was performed continuously with deionized water for 72 hours (replacing the deionized water every 6 hours) to completely remove unreacted small molecules and catalyst. The dialysate was freeze-dried for 48 hours to obtain a white powder of the phosphatidylcholine-modified polymer PC-PGA-1.

[0046] Structural and technical performance characteristics: Mass percentage of phosphatidylcholine structural units: Fourier transform infrared spectroscopy (FT-IR) was used at 1240 cm⁻¹. -1 A P=O stretching vibration peak appears at 1088 cm⁻¹. -1 The peak of POC stretching vibration appears at δ=3.2ppm, and the 1H-NMR spectrum (1H-NMR, based on the -N peak at δ=3.2ppm) shows a similar phenomenon. + The ratio of the integrated area of ​​the (CH3)3 methyl proton peak to the polyγ-glutamic acid backbone proton peak was calculated. The mass percentage of phosphatidylcholine structural units in the obtained PC-PGA-1 was 10.2 wt%. Figure 1 , Figure 2 As shown.

[0047] Phosphorus content determination: The purified PC-PGA-1 sample was quantitatively analyzed by inductively coupled plasma atomic emission spectrometry (ICP-OES), and the phosphorus (P) content in the modified polymer was found to be 0.51 wt%.

[0048] Example 2: Preparation of phosphatidylcholine-modified polymer (modified polymer PC-PVA-2) The specific steps are as follows: (1) Preparation of activated phosphatidylcholine derivatives 50 parts by mass of glycerol phosphocholine ester (GPC) and 60 parts by mass of succinic anhydride were dissolved in 500 parts by volume of dry dimethyl sulfoxide (DMSO), and 2.5 parts by mass of 4-dimethylaminopyridine (DMAP) were added. The reaction was carried out at 60°C under nitrogen protection for 12 h. After the reaction was completed, excess cold acetone was added to precipitate the product, which was then filtered. The precipitate was washed three times with anhydrous ethanol and dried under vacuum at 40°C for 24 h to obtain a carboxyl-terminated activated phosphatidylcholine derivative.

[0049] (2) Graft copolymerization reaction 50 parts by mass of polyvinyl alcohol (average degree of polymerization of 1750, degree of alcoholysis of 98.0%, water solubility of ≥10 g / L at 25°C) were fully dissolved in 600 parts by volume of anhydrous DMSO. 45 parts by mass of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC·HCl) and 27 parts by mass of N-hydroxysuccinimide (NHS) were added, and the mixture was activated and stirred at room temperature (25°C) for 2 h.

[0050] Subsequently, 65 parts by mass of the activated phosphatidylcholine derivative obtained in step (1) above were dissolved in 300 parts by volume of DMSO and slowly added dropwise to the above polyvinyl alcohol solution. After the addition was completed, the mixture was heated to 60°C and reacted for 24 hours.

[0051] (3) Purification and drying After the reaction mixture was cooled to room temperature, it was poured into 4000 parts by volume of anhydrous ethanol to initiate precipitation. The precipitate was redissolved in a small amount of distilled water and placed in a dialysis bag with a molecular weight cutoff of 10000 Da. Dialysis was performed continuously with deionized water for 72 hours (replacing the deionized water every 6 hours) to completely remove unreacted small molecules and catalyst. The dialysate was freeze-dried for 48 hours to obtain a pale yellow solid powder of the phosphatidylcholine-modified polymer PC-PVA-2.

[0052] Structural and technical performance characteristics: Mass percentage of phosphatidylcholine structural units: Fourier transform infrared spectroscopy (FT-IR) was used at 1242 cm⁻¹. -1 A strong P=O stretching vibration peak appears at 1085 cm⁻¹. -1 A strong POC stretching vibration peak appears at δ=3.2ppm) and the 1H-NMR spectrum shows a strong POC stretching vibration peak. + The ratio of the integrated area of ​​the (CH3)3 methyl proton peak to the polyvinyl alcohol main chain proton peak was calculated. The mass percentage of phosphatidylcholine structural units in the obtained PC-PVA-2 was 49.3 wt%. Figure 1 , Figure 2 As shown.

[0053] Phosphorus content determination: The purified PC-PVA-2 sample was quantitatively analyzed by inductively coupled plasma atomic emission spectrometry (ICP-OES), and the phosphorus (P) content in the modified polymer was found to be 4.88 wt%.

[0054] Application Example 1: Preparation of Supramolecular Micellar Compositions This embodiment provides a supramolecular micelle composition (denoted as composition 1), with the following amounts of each component: 4-Butylresorcinol: 0.5 parts by weight; N-Lauroylhydroxyproline: 1.0 parts by weight; Polyethylene glycol-polycaprolactone block copolymer PEG-b-PCL: 5.0 parts by weight; PC-PGA-1: 0.5 parts by weight; Deionized water: 93.0 parts by weight.

[0055] Its specific preparation method includes the following steps: Preparation of S1 composite active core Weigh 0.5 parts by weight of 4-butylresorcinol and 1.0 parts by weight of N-lauroyl hydroxyproline according to the specified ratio and place them in a reaction vessel. Add 10 parts by volume of anhydrous ethanol to dissolve them completely. Remove the anhydrous ethanol by rotary evaporation under reduced pressure at 45°C (solvent evaporation treatment) to obtain a homogeneous molten co-extracted composite active core.

[0056] S2 micelle formation Add 5.0 parts by mass of PEG-b-PCL to the composite active core obtained in step S1, and then add 80 parts by volume of deionized water. Stir at 800 rpm for 30 min at 55°C, and then homogenize and cycle three times at 60 MPa pressure using a high-pressure homogenizer (dispersion and self-assembly treatment) to form a stable micelle intermediate dispersion coating the composite active core.

[0057] S3 outer layer modification Dissolve 0.5 parts by mass of PC-PGA-1 in 13 parts by volume of deionized water and slowly add it dropwise to the micelle intermediate dispersion obtained in step S2. Maintain magnetic stirring at 400 rpm for 1 hour at 25°C to allow PC-PGA-1 to settle and self-assemble to coat the outermost layer of the micelles, thus obtaining supramolecular micelle composition 1 with phosphatidylcholine modified on the outer layer.

[0058] Physicochemical properties and structural characterization: Particle size and distribution: The average hydrodynamic particle size of the obtained composition 1 was 85.4 nm and the polydispersity index (PDI) was 0.128, which was determined by dynamic light scattering (DLS). It was in the state of monodisperse particles.

[0059] Micellar surface potential (Zeta potential): The measured zeta potential of the micelle surface is -18.5mV.

[0060] Encapsulation efficiency determination: The encapsulation efficiency of 4-butylresorcinol in composition 1 was determined by high performance liquid chromatography (HPLC) to be 92.4% and that of N-lauroyl hydroxyproline to be 95.1%.

[0061] Application Example 2: Preparation of supramolecular micelle composition (composition 2) This embodiment provides another supramolecular micelle composition with low surface potential (denoted as composition 2), the specific formulation of which is as follows: 4-Butylresorcinol: 1.2 parts by weight; N-Myristoyl Hydroxyproline: 4.0 parts by weight; Polyethylene glycol-polylactic acid block copolymer PEG-b-PLA: 18.0 parts by weight; PC-PGA-1: 0.6 parts by weight; Deionized water: 76.2 parts by weight.

[0062] Its specific preparation method includes the following steps: Preparation of S1 composite active core Weigh 1.2 parts by weight of 4-butylresorcinol and 4.0 parts by weight of N-myristoylhydroxyproline according to the formula and place them in a reaction vessel. Heat to 65°C to allow the two to completely eutectic (eutectic treatment). Maintain constant temperature and stir for 15 minutes. After cooling to room temperature, a uniformly cured composite active core is obtained.

[0063] S2 micelle formation The composite active core obtained in step S1 was mixed with 18.0 parts by mass of amphiphilic block polymer B, and 60 parts by volume of deionized water was added. The mixture was ultrasonically dispersed at 50°C for 20 min, and then placed in a high-shear emulsifier and sheared at 10,000 rpm for 10 min (dispersion and self-assembly treatment) to obtain a micelle intermediate dispersion.

[0064] S3 outer layer modification Dissolve 0.6 parts by mass of PC-PGA-1 in 16.2 parts by volume of deionized water and slowly add it to the micelle intermediate dispersion obtained in step S2. Stir at 500 rpm for 1.5 h at 30 °C to allow PC-PGA-1 to complete self-assembly deposition on the outer layer of the micelles, thus obtaining supramolecular micelle composition 2 (aqueous dispersion) with phosphatidylcholine modified on the outer layer.

[0065] Physicochemical properties and structural characterization: Particle size and distribution: The average hydrodynamic particle size of the obtained composition 2 was 112.6 nm and the polydispersity index (PDI) was 0.145, as determined by dynamic light scattering (DLS).

[0066] Micellar surface potential (Zeta potential): The measured zeta potential of the micelle surface is -5.8mV.

[0067] Encapsulation efficiency determination: The encapsulation efficiency of 4-butylresorcinol in composition 2 was determined by high performance liquid chromatography (HPLC) to be 94.1% and that of N-myristoylhydroxyproline to be 96.3%.

[0068] Application Example 3: Preparation of Supramolecular Micellar Composition This embodiment provides a supramolecular micelle composition with high surface potential (denoted as composition 3), wherein the proportions of each component are within the range defined in claim 1, as follows: 4-Butylresorcinol: 1.8 parts by weight; N-Palmitoylhydroxyproline: 8.0 parts by weight; PEG-b-PCL-b-PLA: 25.0 parts by weight; PC-PVA-2: 4.5 parts by weight; Deionized water: 60.7 parts by weight.

[0069] The specific preparation method is as follows: Preparation of S1 composite active core 1.8 parts by weight of 4-butylresorcinol and 8.0 parts by weight of N-palmitoylhydroxyproline were dissolved in 15 parts by volume of anhydrous ethanol, and the solvent was removed by rotary evaporation at 50°C to obtain the composite active core.

[0070] S2 micelle formation The above-mentioned composite active core was mixed with 25.0 parts by weight of amphiphilic block polymer C, and 50 parts by volume of deionized water was added. The mixture was then subjected to high-speed shearing at 60°C (8000 rpm, 15 min) to obtain a micelle intermediate dispersion.

[0071] S3 outer layer modification Dissolve 4.5 parts by weight of PC-PVA-2 in 10.7 parts by volume of deionized water, and slowly add it dropwise to the above micelle intermediate dispersion. Stir at 25°C for 1 hour to obtain supramolecular micelle composition 3.

[0072] Physicochemical properties and structural characterization: Particle size and distribution: The average hydraulic particle size is 68.2 nm, and the polydispersity index (PDI) is 0.115.

[0073] Micellar surface potential (Zeta potential): The measured zeta potential of the micelle surface was -48.2 mV.

[0074] Encapsulation efficiency determination: 4-Butylresorcinol encapsulation efficiency was 96.8%, and N-palmitoylhydroxyproline encapsulation efficiency was 98.1%.

[0075] Application Example 4: Preparation of Supramolecular Micellar Composition The specific formula for this embodiment is as follows: 4-Butylresorcinol: 2.0 parts by weight; N-Lauroylhydroxyproline: 10.0 parts by weight; PEG-b-PCL: 30.0 parts by weight; PC-PGA-1: 5.0 parts by weight; Deionized water: 53.0 parts by weight.

[0076] The specific preparation method is as follows: Preparation of S1 composite active core 2.0 parts by weight of 4-butylresorcinol and 10.0 parts by weight of N-lauroyl hydroxyproline were dissolved in 20 parts by volume of anhydrous ethanol, and the solvent was removed by rotary evaporation under reduced pressure at 50°C (solvent evaporation treatment) to obtain a homogeneous molten co-extracted composite active core.

[0077] S2 micelle formation Add 30.0 parts by mass of PEG-b-PCL and 40 parts by volume of deionized water to the above composite active core, stir at 1000 rpm for 30 min at 60 °C, and then homogenize and cycle 4 times at 80 MPa pressure using a high-pressure homogenizer (dispersion and self-assembly treatment) to obtain a micelle intermediate dispersion.

[0078] S3 outer layer modification Dissolve 5.0 parts by weight of PC-PGA-1 in 13 parts by volume of deionized water, and slowly add it dropwise to the above micelle intermediate dispersion. Maintain magnetic stirring at 500 rpm for 2 hours at 25°C to allow PC-PGA-1 to complete the outer layer self-assembly and coating, thus obtaining supramolecular micelle composition 4.

[0079] Physicochemical properties and structural characterization: Particle size and distribution: The average hydraulic particle size is 98.6 nm, and the polydispersity index (PDI) is 0.132.

[0080] Micellar surface potential (Zeta potential): The measured zeta potential of the micelle surface is -38.5mV.

[0081] Encapsulation efficiency determination: 4-Butylresorcinol encapsulation efficiency was 95.2%, and N-lauroyl hydroxyproline encapsulation efficiency was 97.4%.

[0082] Application Example 5: Preparation of Supramolecular Micellar Composition The difference between this embodiment and application embodiment 1 is that 0.1 parts by mass of pterostilbene are added in the preparation of the S1 composite active core, and the amount of deionized water is adjusted accordingly to 92.9 parts by mass.

[0083] Formula components: 0.5 parts by weight of 4-butylresorcinol, 1.0 part by weight of N-lauroyl hydroxyproline, 0.1 part by weight of pterostilbene, 5.0 parts by weight of PEG-b-PCL, 0.5 parts by weight of PC-PGA-1, and 92.9 parts by weight of deionized water.

[0084] Preparation steps: In step S1, 0.5 parts by weight of 4-butylresorcinol, 1.0 parts by weight of N-lauroyl hydroxyproline and 0.1 parts by weight of pterostilbene are dissolved together in ethanol and rotary evaporated to form a composite active core containing pterostilbene; steps S2 and S3 are the same as in application example 1.

[0085] Structural characterization: The average hydrodynamic particle size was 88.2 nm, the PDI was 0.121, the Zeta potential was -18.1 mV, the encapsulation efficiency of 4-butylresorcinol was 93.1%, and the encapsulation efficiency of pterostilbene was 94.8%.

[0086] Application Example 6: Preparation of Supramolecular Micellar Composition The difference between this embodiment and the application embodiment is that 0.3 parts by mass of pterostilbene are added in the preparation of the S1 composite active core, and the amount of deionized water is adjusted accordingly to 52.7 parts by mass.

[0087] Formula components: 2.0 parts by weight of 4-butylresorcinol, 10.0 parts by weight of N-lauroyl hydroxyproline, 0.3 parts by weight of pterostilbene, 30.0 parts by weight of PEG-b-PCL, 5.0 parts by weight of PC-PGA-1, and 52.7 parts by weight of deionized water.

[0088] Preparation steps: In step S1, 2.0 parts by weight of 4-butylresorcinol, 10.0 parts by weight of N-lauroyl hydroxyproline and 0.3 parts by weight of pterostilbene are dissolved together and the solvent is evaporated to dryness; steps S2 and S3 are the same as in application example 4.

[0089] Structural characterization: The average hydrodynamic particle size was 101.5 nm, the PDI was 0.138, the Zeta potential was -38.1 mV, the encapsulation efficiency of 4-butylresorcinol was 95.8%, and the encapsulation efficiency of pterostilbene was 96.5%.

[0090] Application Example 7: Preparation of 4-Butylresorcinol Aqueous Solution The difference between this embodiment and application embodiment 1 is that the lipophilic amino acid derivative, amphiphilic block polymer and phosphatidylcholine modified polymer are removed, and only 4-butylresorcinol and water are retained.

[0091] Formula components: 0.5 parts by weight of 4-butylresorcinol, 99.5 parts by weight of deionized water.

[0092] Preparation steps: Add 0.5 parts by weight of 4-butylresorcinol directly to 99.5 parts by weight of deionized water, and stir magnetically at 25°C until completely dissolved to obtain a pure active aqueous solution.

[0093] Structural characterization: DLS detection does not show micellar scattering signals.

[0094] Preparation of the comparative composition in Application Example 8 The difference between this embodiment and application embodiment 1 is that the lipophilic amino acid derivative is removed and an equal amount (1.0 parts by mass) of amphiphilic block polymer is added as a substitute (i.e., the total amount of PEG-b-PCL is 6.0 parts by mass).

[0095] Formula components: 0.5 parts by weight of 4-butylresorcinol, 6.0 parts by weight of PEG-b-PCL, 0.5 parts by weight of PC-PGA-1, and 93.0 parts by weight of deionized water.

[0096] Preparation steps: Skip the S1 core co-melting step; directly dissolve 0.5 parts by mass of 4-butylresorcinol and 6.0 parts by mass of PEG-b-PCL in deionized water for self-assembly, and then add PC-PGA-1 modification.

[0097] Structural characterization: The average hydrodynamic particle size was 124.6 nm, and the PDI was 0.215; the encapsulation efficiency of 4-butylresorcinol decreased to 71.3%.

[0098] Preparation of the comparative composition in Example 9 The difference between this embodiment and application embodiment 1 is that the amphiphilic block polymer and phosphatidylcholine modified polymer are removed, and an equal amount of water (5.5 parts by mass) is added to make up the difference.

[0099] Formula components: 0.5 parts by weight of 4-butylresorcinol, 1.0 part by weight of N-lauroyl hydroxyproline, and 98.5 parts by weight of deionized water.

[0100] Preparation steps: The composite core obtained by S1 is directly mixed with deionized water and dispersed by high-speed shearing, without polymer coating or outer layer modification steps.

[0101] Structural characterization: It forms an irregular hydrophobic precipitate / crystallized suspension, and obvious stratification and precipitation occur after standing for 2 hours. It cannot form stable supramolecular micelles.

[0102] Preparation of the comparative composition in Application Example 10 The difference between this embodiment and application embodiment 1 is that the phosphatidylcholine modified polymer (PC-PGA-1) is removed, and an equal amount (0.5 parts by mass) of deionized water is added to make up the difference.

[0103] Formula components: 0.5 parts by weight of 4-butylresorcinol, 1.0 part by weight of N-lauroyl hydroxyproline, 5.0 parts by weight of PEG-b-PCL, and 93.5 parts by weight of deionized water.

[0104] Preparation steps: Perform the S1 composite active core preparation and S2 micelle formation steps sequentially, but do not perform the S3 outer layer modification step.

[0105] Structural characterization: The average hydrodynamic particle size was 82.1 nm, the PDI was 0.135, the Zeta potential was -8.3 mV, and the encapsulation efficiency of 4-butylresorcinol was 91.8%.

[0106] The particle size distribution diagrams of DLS in Application Examples 1, 4, and 9 are shown below. Figure 3 As shown.

[0107] Test Example 1: Performance Testing of Supramolecular Micelle Compositions. The following four functional tests were conducted on the samples prepared in Application Examples 1–10: 1. Brief Description of Testing Methods (1) Chemical stability and anti-discoloration test of active ingredients: Each group of samples was sealed and placed in a constant temperature incubator at 45℃ for accelerated high-temperature storage for 60 days. After 60 days, the color difference change of the samples ($\DeltaE$) was measured using a spectrophotometer; at the same time, the residual rate (%) of 4-butylresorcinol in the samples was determined by high performance liquid chromatography (HPLC).

[0108] (2) Skin irritation and cytotoxicity tests (in vitro replacement test): A 3D reconstructed human epidermal model (EpiKutis®) was used. Samples (10 μL) from each group were applied to the model surface and incubated at 37°C with 5% CO2 for 24 hours. Epidermal cell viability (%) was determined using the MTT assay, and the release of the inflammatory factor IL-1α in the culture medium (pg / mL) was detected using an ELISA kit.

[0109] (3) In vitro transdermal absorption and skin retention test (Franz diffusion cell assay): A Franz vertical diffusion cell was used, with isolated Bama pig skin as a barrier. The receiving cell was filled with PBS buffer at pH 7.4. Samples (0.5 mL) from each group were added to the supply cell and diffused continuously at 32℃ and 600 rpm for 24 h. After 24 h, the skin was removed, the stratum corneum was peeled off, and homogenized extraction was performed. The cumulative retention of 4-butylresorcinol in the epidermis and dermis (μg / cm³) was determined by HPLC. 2 ).

[0110] (4) Tyrosinase activity inhibition and melanin production inhibition test: The B16-F10 melanoma cell system was used. B16-F10 cells were treated with culture medium containing nMα-MSH and non-toxic concentrations of each group of samples for 48 h. After cell lysis, the relative content of intracellular melanin was measured at 405 nm using the NaOH lysis method, and the melanin production inhibition rate (%) was calculated; at the same time, the intracellular tyrosinase activity inhibition rate (%) was measured using L-DOPA as a substrate.

[0111] 2. Test Results The functional test results of Application Examples 1–10 (including Compositions 1–6 and Comparative Examples 1–4) are shown in Tables 1 and 2: Table 1

[0112] Table 2

[0113] As shown in Tables 1 and 2, the chemical stability and degree of discoloration of the active ingredient directly depend on the integrity of the supramolecular micelle coating structure. In Application Examples 7 and 9, due to the lack of a polymer coating barrier, the active ingredient underwent significant degradation at high temperatures, accompanied by severe color changes. In Application Examples 1–6, thanks to complete micelle coating, the residual rate of the active ingredient remained at a high level, and there was virtually no color change in appearance. Application Example 10, lacking an outer polymer protection layer, exhibited stability indices between those of a pure aqueous solution and a complete micelle system.

[0114] Regarding skin irritation and epidermal retention, the data showed that each layer of the micelle structure played a specific role. Application Example 7 exhibited the lowest cell survival rate and the highest release of inflammatory factors, indicating that the unencapsulated active ingredient had direct irritant properties. Application Examples 1–6, through biomimetic encapsulation with a phosphatidylcholine-modified outer layer, showed improved cell survival rate and significantly reduced inflammatory factor release. Furthermore, compared to Application Example 8 without an amino acid core and Application Example 10 without an outer layer, Application Examples 1–6 showed significantly higher epidermal retention, demonstrating that the combined use of the lipophilic amino acid derivative core and the phosphatidylcholine outer layer played a crucial role in promoting the accumulation of active ingredients in the epidermal layer.

[0115] Regarding the inhibition of melanin production and tyrosinase activity, the differences in efficacy among the embodiments reflect the efficiency of the drug delivery carrier and the synergistic mechanism between the components. Application Examples 1–4, due to their higher skin retention and transdermal efficiency, exhibited higher intracellular melanin inhibition rates than Application Examples 7–10. Building upon this, Application Examples 5 and 6, after introducing pterostilbene into the core, further increased the inhibition rates of melanin production and tyrosinase activity, showing a positive correlation with increasing pterostilbene dosage, confirming a synergistic melanin-inhibiting effect between pterostilbene and the main component in the composite core.

[0116] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A supramolecular micelle composition, characterized in that, The following components are included in parts by mass: 4-Butylresorcinol, 0.5-2.0 parts; Lipophilic amino acid derivatives, 1.0-10.0 parts; Amphiphilic block polymer, 5.0-30.0 parts; Phosphatidylcholine modified polymer, 0.5-5.0 parts; The supramolecular micelle composition comprises, from the inside out, a core layer, a polymer coating layer, and a functionalized outer layer; The core layer comprises 4-butylresorcinol and lipophilic amino acid derivatives; The lipophilic amino acid derivative is an amino acid derivative containing a fatty chain structure; The polymer coating layer is formed of an amphiphilic block polymer, which includes hydrophilic blocks and hydrophobic blocks, and the mass ratio of the hydrophilic blocks to the hydrophobic blocks is 1:0.5-1:

5. The functionalized outer layer is formed from a phosphatidylcholine-modified polymer.

2. The supramolecular micelle composition according to claim 1, characterized in that, The lipophilic amino acid derivative is a hydroxyproline derivative modified with a fatty acid chain, wherein the fatty acid chain has 12-16 carbon atoms and is connected to the hydroxyproline backbone by an amide bond or an ester bond.

3. The supramolecular micelle composition according to claim 1, characterized in that, The number-average molecular weight of the hydrophilic blocks in the amphiphilic block polymer is 500-20000, and the number-average molecular weight of the hydrophobic blocks is 500-30000; the number-average molecular weight of the amphiphilic block polymer is 1000-50000; and the number of carbon atoms in the repeating structural units of the hydrophobic blocks is C6-C24.

4. The supramolecular micelle composition according to claim 3, characterized in that, After the amphiphilic block polymer forms micelles, the absolute value of the surface potential of the micelles is 5-50 mV.

5. The supramolecular micelle composition according to claim 1, characterized in that, The phosphatidylcholine modified polymer is a modified polymer formed by connecting basic polymer segments with phosphatidylcholine structural units, wherein the mass percentage of the phosphatidylcholine structural units is 10%-50%.

6. The supramolecular micelle composition according to claim 5, characterized in that, The phosphorus content in the phosphatidylcholine modified polymer is 0.5wt%-5.0wt%.

7. The supramolecular micelle composition according to claim 5, characterized in that, The number average molecular weight of the base polymer segments of the phosphatidylcholine modified polymer is 2000-90000.

8. The supramolecular micelle composition according to any one of claims 5, 6, and 7, characterized in that, The phosphatidylcholine-modified polymer was prepared by the following method: A water-soluble basic polymer segment containing reactive functional groups is grafted onto an activated phosphatidylcholine derivative to covalently link the phosphatidylcholine structural unit to the side chain or end group of the basic polymer segment. After purification, the phosphatidylcholine-modified polymer is obtained.

9. The supramolecular micelle composition according to claim 1, characterized in that, The composition further includes pterostilbene, which is 0.1-0.3 parts by weight; the pterostilbene, together with 4-butylresorcinol and a lipophilic amino acid derivative, forms the core layer.

10. A method for preparing the supramolecular micelle composition according to any one of claims 1-9, characterized in that, Includes the following steps: Preparation of S1 composite active core: 4-Butylresorcinol, lipophilic amino acid derivatives, and optionally pterostilbene are subjected to co-melting or solvent evaporation treatment to obtain a composite active core. S2 Micelle Formation: The composite active core obtained in step S1 and the amphiphilic block polymer are added to the dispersion medium, and after mixing, dispersion and self-assembly treatment, a micelle dispersion system is obtained; S3 Outer layer modification: Phosphatidylcholine-modified polymer is added to the micelle dispersion system obtained in step S2, and the mixture is then mixed and dispersed to obtain the supramolecular micelle composition.

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