Enzyme response type nasal cavity cool feeling composition as well as preparation method and application thereof

Abstract

The invention discloses an enzyme response type nasal cavity cool feeling composition as well as a preparation method and application thereof, and relates to the technical field of food additives. The enzyme response type nasal cavity cooling composition comprises a cooling agent and a coating layer coating the surface of the cooling agent, the coating layer comprises chitosan, the deacetylation degree of the chitosan is 60%-95%, and the molecular weight of the chitosan is 30-100 kDa. According to the invention, the enzyme-responsive cool-feeling composition is stably anchored on the surface of mucous membrane of a nasal cavity through the synergy of the electrostatic adsorption effect of a chitosan wrapping layer and mucoprotein of the nasal cavity and the specific hydrolysis effect of lysozyme on beta-1, 4-glucosidic bond of chitosan, and the adsorption efficiency of the enzyme-responsive cool-feeling composition and mucoprotein is enhanced by regulating and controlling the deacetylation degree and molecular weight of chitosan; after adsorption, the endogenous lysozyme in the nasal cavity hydrolyzes the chitosan skeleton to release the cooling agent, so that lasting cool feeling is realized.

Description

Technical Field

[0001] This invention relates to the field of food additives, and in particular to an enzyme-responsive nasal cooling composition, its preparation method, and its application. Background Technology

[0002] Cooling agents are a general term for chemical substances that produce a cooling effect but are not strongly medicinal. They stimulate cold receptors in the body, producing a cooling sensation that provides comfort and pleasure. Commonly used cooling agents include L-menthol and N,2,3-trimethyl-2-isopropylbutyramide (WS-23). ​​Cooling agents are often used in conjunction with atomized flavorings, which are then atomized and delivered to various parts of the respiratory tract through the mouth, providing a cooling sensation. However, since atomized flavorings are inhaled as aerosols, their residence time in the nasal cavity is extremely short upon exhalation. This results in relatively little cooling agent being retained on the nasal cavity surface, with most diffusing into the mouth, throat, and other areas. This limits the area of ​​action of the cooling agents in atomized flavorings, making it difficult to achieve a significant nasal cooling sensation and thus restricting the consumer's cooling experience. Summary of the Invention

[0003] The main objective of this invention is to propose an enzyme-responsive nasal cooling composition, its preparation method, and its application, aiming to solve the problem that existing nasal cooling compositions are difficult to achieve a significant nasal cooling sensation.

[0004] To achieve the above objectives, the present invention provides an enzyme-responsive nasal cooling composition, comprising a cooling agent and a coating layer encapsulating the surface of the cooling agent; the coating layer comprises chitosan, wherein the degree of deacetylation of the chitosan is 60% to 95% and the molecular weight is 30 to 100 kDa.

[0005] In one embodiment, the chitosan has a degree of deacetylation of 85% to 95% and a molecular weight of 60 to 100 kDa.

[0006] In one embodiment, the cooling agent includes one or more of L-menthol, L-menthone, piperonone, menthyl acetate, menthyl lactate, isomenthone, isomenthone, L-menthone glyceryl ketal, isomenthone acetate, menthyl succinate, camphor, 1,8-cineole, linalool, carvacrol, thymol, α-fungin, cooling agent Icillin, cooling agent WS-3, cooling agent WS-5, cooling agent WS-10, cooling agent WS-12, cooling agent WS-14, cooling agent WS-23, and cooling agent WS-27; and / or, the chitosan includes one or more of carboxymethyl chitosan, carboxyethyl chitosan, and hydroxypropyl chitosan.

[0007] The present invention also provides a method for preparing the enzyme-responsive nasal cooling composition described above, comprising the following steps:

[0008] Step S10: Dissolve the cooling agent in an organic solvent to obtain a dispersion;

[0009] Step S20: Add the dispersion to the chitosan aqueous solution, add the crosslinking agent solution, and then stir, centrifuge, wash and dry to obtain the enzyme-responsive nasal cooling composition.

[0010] In one embodiment, the crosslinking agent includes one or more of sodium tripolyphosphate, calcium chloride, sodium polyphosphate, glutaraldehyde, salicylaldehyde, isocyanate, tannic acid, and lysine; and / or, the organic solvent includes one or more of propylene glycol, ethanol, tricarboxylic acid glyceride, and lactic acid.

[0011] In one embodiment, in step S10, the concentration of the dispersion is 5% to 15% w / v; and / or, in step S20, the concentration of the chitosan aqueous solution is 1.0% to 3.0% w / v.

[0012] In one embodiment, step S20 specifically involves: adding the dispersion to the chitosan aqueous solution, adding a crosslinking agent solution dropwise while continuously stirring, controlling the pH of the system to be 4.0–5.0, stirring at room temperature for 50–70 min, adding alkali solution to adjust the pH to 5.5–6.5, centrifuging at 10,000–14,000 rpm for 10–30 min, washing the precipitate with deionized water, and spray drying to obtain the enzyme-responsive nasal cooling composition.

[0013] In one embodiment, in step S20, the dropping rate is 0.5 to 1 mL / min.

[0014] In one embodiment, the mass ratio of chitosan to the crosslinking agent in the chitosan aqueous solution is 4 to 6:1.

[0015] The present invention also provides an atomized fragrance, wherein the atomized fragrance comprises the enzyme-responsive nasal cooling composition described above.

[0016] 1. The technical solution of the present invention encapsulates the cooling agent in a coating layer and controls the selection of chitosan as the material of the coating layer. On the one hand, the positively charged chitosan molecules and the negatively charged mucin are stably bound through charge adsorption, targeting and enriching the enzyme-responsive nasal cooling composition in the nasal cavity, increasing its retention amount and retention time in the nasal cavity, thereby allowing the cooling agent encapsulated inside the coating layer to exist stably in the nasal cavity for a long time, producing a cooling sensation in the nasal cavity. On the other hand, the lysozyme in the nasal cavity forms a strictly matched enzyme-substrate specific recognition with the β-1,4-glycosidic bond of chitosan, and then the lysozyme hydrolyzes the β-1,4-glycosidic bond of chitosan, releasing the internal cooling agent, achieving the purpose of continuous cooling sensation in the nasal cavity. This invention utilizes the synergistic effect of the electrostatic adsorption between the chitosan coating layer and nasal mucin, and the specific hydrolysis of chitosan β-1,4-glycosidic bonds by lysozyme, to stably anchor an enzyme-responsive cooling composition on the nasal mucosa surface. By controlling the degree of deacetylation and molecular weight of chitosan, its adsorption efficiency with mucin is enhanced. After adsorption, endogenous lysozyme in the nasal cavity hydrolyzes the chitosan backbone to release the cooling agent, thereby achieving a long-lasting cooling sensation. Compared to cooling agents that only provide a broad cooling sensation in the mouth, throat, and upper lungs, the enzyme-responsive nasal cooling composition of this invention, based on a dual activation mechanism of charge adsorption and enzyme-responsive release, significantly prolongs the residence time of the cooling agent in the nasal cavity, and the cooling sensation is specific, released only in the nasal cavity.

[0017] 2. The technical solution of this invention controls the degree of deacetylation of chitosan to 60%–95%, thereby regulating the number of free amino groups on the chitosan surface and consequently the charge density of the chitosan surface, thus achieving stable and efficient adsorption of chitosan onto the mucin in the nasal cavity. Simultaneously, by controlling the molecular weight of chitosan to 30–100 kDa, it achieves uniform encapsulation of the cooling agent while allowing chitosan to more easily penetrate nasal mucus and contact with lysozyme in the nasal cavity, thereby achieving a cooling sensation. Furthermore, chitosan with a molecular weight of 30–100 kDa provides a moderate number of free amino groups per unit mass, and the chitosan molecular chains of suitable length form a dense network through cross-linking with a cross-linking agent, improving the encapsulation rate of the cooling agent, resulting in better mechanical strength and facilitating subsequent drying. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1This is a schematic flowchart of an embodiment of the preparation method of the enzyme-responsive nasal cooling composition of the present invention;

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Furthermore, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies both A and B. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] Cooling agents stimulate the body's cold receptors, producing a cooling sensation that provides comfort and pleasure. During use, cooling agents are often combined with atomized flavorings, which, after being atomized, reach various parts of the respiratory tract through the mouth, providing a cooling sensation. However, since atomized flavorings are inhaled as aerosols, their residence time in the nasal cavity upon exhalation is extremely short. This results in relatively little cooling agent being retained on the nasal cavity surface, with most diffusing into the mouth, throat, and other areas. This limits the area of ​​action of the cooling agent in atomized flavorings, making it difficult to achieve a significant nasal cooling sensation and thus restricting the consumer's cooling experience.

[0024] The present invention provides an enzyme-responsive nasal cooling composition, comprising a cooling agent and a coating layer encapsulating the surface of the cooling agent; wherein the coating layer comprises chitosan, the degree of deacetylation of chitosan being 60% to 95% and the molecular weight being 30 to 100 kDa.

[0025] The technical solution of this invention involves encapsulating a cooling agent in a coating layer, and controlling the selection of chitosan as the material of the coating layer. The nasal cavity pH is 5.5–6.5. On one hand, the free amino groups (-NH2) in the chitosan molecular chain are protonated to -NH3 in the pH environment of the nasal cavity. +This results in chitosan exhibiting a high degree of positive charge. The nasal cavity contains a complex layer of fluid covering the surface of the nasal mucosa, namely nasal mucus. Nasal mucus is mainly composed of water and mucin. The sialic acid at the sugar chain end of the mucin ionizes into carboxyl groups in the pH environment of the nasal cavity, forming a negative charge barrier. Positively charged chitosan molecules and negatively charged mucin bind stably through charge adsorption, increasing their retention amount and retention time in the nasal cavity. This allows the cooling agent encapsulated inside the coating layer to remain stably in the nasal cavity for a long time, producing a cooling sensation in the nasal cavity. On the other hand, different parts of the human respiratory tract contain different concentrations of lysozyme. Specifically, the concentrations of lysozyme in the anterior nasal cavity, larynx, and oral cavity are 1.5–2.2 μg / mL, 0.5–1.0 μg / mL, and 0.3–0.8 μg / mL, respectively. The lysozyme content in the anterior nasal cavity is significantly higher than that in the larynx and oral cavity. Moreover, the nasal mucus layer is thinner (30–50 μm) than the oral mucus layer (70–150 μm), making it easier for the enzyme-responsive nasal cooling composition to penetrate the nasal mucus and make efficient contact with the lysozyme in the anterior nasal cavity. Furthermore, the binding force of lysozyme to the N-acetylglucosamine (GlcNAc) residues of chitosan is significantly higher than that of oral α-amylase to the N-acetylglucosamine residues of chitosan. This irreversible conformational specificity makes the enzyme-responsive nasal cooling composition inert in the oral environment and activated only in the high-concentration lysozyme environment of the nasal cavity. When the enzyme-responsive nasal cooling composition comes into contact with lysozyme in the anterior nasal cavity, the active site of lysozyme, Glu35 / Asp52, precisely anchors the N-acetylglucosamine residues of chitosan through a hydrogen bond network. This means that lysozyme and chitosan form a strictly matched enzyme-substrate specific recognition. Subsequently, lysozyme hydrolyzes the β-1,4-glycosidic bonds of chitosan, releasing the internal cooling agent. In summary, the enzyme-responsive nasal cooling composition of this application first achieves stable and prolonged adsorption between the nasal surface and nasal mucus through the synergistic effect of the charge adsorption between chitosan molecules and mucin, and the specific recognition of the β-1,4-glycosidic bonds by lysozyme, thus achieving the purpose of nasal cooling. In addition, chitosan and its derivatives have good biocompatibility and biodegradability. As a food additive, it has both EU (EU) 2022 / 456 and GRAS (GRN 885) certifications, does not damage the nasal mucosa and cilia, and has high safety.

[0026] Furthermore, the technical solution of this invention controls the degree of deacetylation of chitosan to 60%–95%, thereby regulating the number of free amino groups (-NH2) on the chitosan surface. This results in a suitable amount of charge uniformly present on the chitosan surface, and the charge density on the chitosan surface is rationally controlled, thereby achieving stable and efficient adsorption of chitosan to mucin in the nasal cavity. When the degree of deacetylation on the chitosan surface is too low, the charge on the chitosan surface is insufficient, which weakens the binding force between chitosan and mucin in the nasal cavity, thus affecting the retention time and amount of the enzyme-responsive nasal cooling composition in the nasal cavity and reducing the cooling sensation. When the degree of deacetylation on the chitosan surface is too high, the chitosan molecular chain is too rigid, making the coating layer prone to breakage, affecting the stability of the enzyme-responsive nasal cooling composition, and thus affecting the cooling sensation. Meanwhile, by controlling the molecular weight of chitosan to 30–100 kDa, this invention achieves uniform encapsulation of the cooling agent while allowing it to more easily penetrate nasal mucus and contact lysozyme within the nasal cavity. Controlling the molecular weight of chitosan also prolongs the residence time of the enzyme-responsive nasal cooling composition in the nasal cavity, thus achieving a cooling sensation. Furthermore, chitosan with a molecular weight of 30–100 kDa provides a moderate number of free amino groups per unit mass, and the appropriately long chitosan molecular chains form a dense network through cross-linking with a cross-linking agent, improving the encapsulation rate of the cooling agent, resulting in better mechanical strength and facilitating subsequent drying.

[0027] In the embodiments of the present invention, the degree of deacetylation of chitosan is 85% to 95%, and the molecular weight is 60 to 100 kDa.

[0028] The technical solution of this invention further optimizes the degree of deacetylation and molecular weight of chitosan, so that the charge density on the surface of chitosan is in an optimal range, which better achieves stable and efficient adsorption of chitosan to mucin in the nasal cavity; at the same time, it makes chitosan more capable of penetrating nasal mucus, thereby better contacting lysozyme in the nasal cavity. Through the dual effects of charge adsorption and enzyme response, the retention time and amount of enzyme-responsive nasal cooling composition in the nasal cavity are improved, thereby achieving a long-lasting cooling sensation in the nasal cavity.

[0029] In embodiments of the present invention, the cooling agent includes one or more of L-menthol, L-menthone, piperonone, menthyl acetate, menthyl lactate, isomenthone, isoprene, L-menthone glyceryl ketal, isoprene acetate, menthyl succinate, camphor, 1,8-cineole, linalool, carvacrol, thymol, α-furonone, cooling agent Icillin, cooling agent WS-3, cooling agent WS-5, cooling agent WS-10, cooling agent WS-12, cooling agent WS-14, cooling agent WS-23, and cooling agent WS-27; and / or, the chitosan includes one or more of carboxymethyl chitosan, carboxyethyl chitosan, and hydroxypropyl chitosan. Preferably, the cooling agent includes one or more of menthol, menthyl lactate, and cooling agent WS-23.

[0030] The technical solution of this invention, by rationally setting the type of cooling agent, ensures on the one hand that the selected cooling agent can provide sufficient cooling sensation, and on the other hand, ensures that the cooling agent does not react with the chitosan wall material of the coating layer, thereby smoothly realizing the binding of chitosan with the nasal cavity and smoothly realizing the release of the cooling agent; by rationally setting the type of chitosan, selecting chitosan with better solubility, it is easier to achieve uniform coating of chitosan on the surface of the cooling agent, increasing the residence time of the enzyme-responsive nasal cooling composition in the nasal cavity, and improving the cooling effect.

[0031] like Figure 1 As shown, the present invention also provides a method for preparing the above-mentioned enzyme-responsive nasal cooling composition, comprising the following steps:

[0032] Step S10: Dissolve the cooling agent in an organic solvent to obtain a dispersion;

[0033] Step S20: Add the dispersion to the chitosan aqueous solution, add the crosslinking agent solution, and then stir, centrifuge, wash and dry to obtain the enzyme-responsive nasal cooling composition.

[0034] The technical solution of this invention uses an ionogel method to prepare an enzyme-responsive nasal cooling composition. First, a cooling agent is dissolved in an organic solvent, which is then uniformly dispersed in the organic solvent to obtain a dispersion in which small droplets are uniformly dispersed. These small droplets provide a template for the subsequent coating layer used to encapsulate the cooling agent, facilitating the adhesion and encapsulation of the coating layer. Next, the dispersion is added to a chitosan aqueous solution, where chitosan is uniformly adsorbed onto the surface of the cooling agent droplets in the dispersion. Then, a crosslinking agent is added, which crosslinks different chitosan molecular chains into a network structure, stably encapsulating the cooling agent surface. During stirring, the structure of the coating layer is further optimized, improving the density and mechanical strength of the coating, resulting in a high-performance enzyme-responsive nasal cooling composition.

[0035] In embodiments of the present invention, the crosslinking agent includes one or more of sodium tripolyphosphate (TPP), calcium chloride, sodium polyphosphate, glutaraldehyde, salicylaldehyde, isocyanate, tannic acid, and lysine; and / or, the organic solvent includes one or more of propylene glycol, ethanol, tricarboxylic acid glyceride, and lactic acid.

[0036] The technical solution of this invention, by rationally setting the types of crosslinking agents, enables different chitosan molecular chains to fully bond and crosslink, thereby improving the uniformity and firmness of chitosan coating on the surface of the cooling agent, enhancing the stability of the enzyme-responsive nasal cooling composition, and achieving a long-lasting cooling effect in the nasal cavity; by rationally setting the types of organic solvents, the cooling agent is uniformly and fully dispersed in the form of small droplets, providing favorable conditions for the subsequent loading of the coating layer.

[0037] In embodiments of the present invention, in step S10, the concentration of the dispersion is 5% to 15% w / v; and / or, in step S20, the concentration of the chitosan aqueous solution is 1.0% to 3.0% w / v. Specifically, 5% to 15% w / v means that the mass of the cooling agent in each 100 mL of dispersion is 5 to 15 g, and 1.0% to 3.0% w / v means that the mass of chitosan in each 100 mL of chitosan aqueous solution is 1.0 to 3.0 g.

[0038] The technical solution of this invention controls the concentration of the dispersion liquid to 5%–15% w / v. A suitable dispersion liquid concentration ensures uniform dispersion of the cooling agent droplets. If the concentration is too low, it will affect the coating layer, thus hindering the successful formation of the enzyme-responsive nasal cooling composition. If the concentration is too high, the cooling agent droplets are prone to aggregation, resulting in an uneven enzyme-responsive nasal cooling composition. By rationally setting the concentration of the chitosan aqueous solution, a suitable concentration of chitosan can better encapsulate the cooling agent. If the chitosan solution concentration is too low, the coating layer on the surface of the cooling agent will be uneven and incomplete, affecting the stability of the resulting enzyme-responsive nasal cooling composition. If the chitosan solution concentration is too high, the coating layer formed on the surface of the cooling agent will be too thick, affecting the rapid release of the cooling agent and reducing the cooling sensation.

[0039] In an embodiment of the present invention, step S20 includes: adding the dispersion to a chitosan aqueous solution, slowly adding a crosslinking agent solution dropwise while continuously stirring, controlling the pH of the system to be 4.0-5.0, stirring at room temperature for 50-70 min, adding an alkaline solution to adjust the pH to 5.5-6.5, centrifuging at 10000-14000 rpm for 10-30 min, washing the precipitate with deionized water, and spray drying to obtain an enzyme-responsive nasal cooling composition.

[0040] The technical solution of this invention involves slowly adding a crosslinking agent under continuous stirring, ensuring the crosslinking agent is fully and uniformly dispersed in the system. This avoids the rapid crosslinking of chitosan due to excessive or too rapid addition of the crosslinking agent, which would prevent the cooling agent from being properly encapsulated. This successfully forms a core-shell structured enzyme-responsive nasal cooling composition. Next, stirring at room temperature further optimizes the structure of the coating layer. Then, an alkaline solution is added to adjust the pH, allowing the -NH3 in the coating layer to... + The increased proportion of chitosan results in a positively charged surface. After centrifugation and washing, spray drying preserves particle activity while preventing particle aggregation, yielding a uniform enzyme-responsive nasal cooling composition. Furthermore, chitosan with a molecular weight of 30–120 kDa better meets the viscosity requirements of the spray drying process, facilitating its execution.

[0041] In an embodiment of the present invention, in step S20, the dropping rate is 0.5–1 mL / min. Specifically, the dropping rate of the crosslinking agent is preferably such that the mixture remains clear.

[0042] The technical solution of this invention achieves precise control of the amount of crosslinking agent added by reasonably controlling the dripping speed of the crosslinking agent, thereby enabling different chitosan molecules to crosslink at an appropriate speed and uniformly coat the surface of the cooling agent, while avoiding excessively high local concentrations that could lead to the aggregation of large particles.

[0043] In an embodiment of the present invention, the mass ratio of chitosan to crosslinking agent in the chitosan aqueous solution is 4 to 6:1.

[0044] The technical solution of the present invention achieves a superior structure and high performance by rationally setting the mass ratio of chitosan and cross-linking agent in the chitosan aqueous solution, so that the chitosan is fully cross-linked into a dense coating layer and uniformly wrapped on the surface of the cooling agent, resulting in an enzyme-responsive nasal cooling composition.

[0045] The present invention also provides an atomized fragrance, comprising the above-mentioned enzyme-responsive nasal cooling composition.

[0046] The technical solution of the present invention applies an enzyme-responsive nasal cooling composition with a specific structure to an atomized fragrance. When the atomized fragrance is applied to the mouth and nose, it can achieve a long-lasting cooling sensation in the nasal cavity and improve comfort.

[0047] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the following embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the reagents and materials used in the following embodiments can be obtained commercially. The carboxymethyl chitosan used in Examples 1-5 and Comparative Examples 1-4 was purchased from Huantai County Jinhu Chitosan Products Co., Ltd.

[0048] Example 1

[0049] An enzyme-responsive nasal cooling composition includes a cooling agent WS-23 and carboxymethyl chitosan coated on the surface of the cooling agent WS-23. The carboxymethyl chitosan has a degree of deacetylation of 85% and a molecular weight of 60 kDa. The preparation method of this enzyme-responsive nasal cooling composition includes the following steps:

[0050] Step S10: Dissolve the cooling agent WS-23 in ethanol, stir well, and obtain 1000 mL of dispersion with a concentration of 10% w / v.

[0051] Step S20: Prepare 1000 mL of a 2.0% w / v carboxymethyl chitosan aqueous solution. Add the dispersion prepared in step S10 to the above carboxymethyl chitosan aqueous solution. Slowly add 500 mL of a 2 mg / mL sodium tripolyphosphate aqueous solution while continuously stirring, controlling the pH of the system to 4.0. Maintain the clear state of the mixture by increasing the dropping rate of the sodium tripolyphosphate aqueous solution. Stir at room temperature for 60 min, then add sodium hydroxide solution to adjust the pH to 5.8. Centrifuge at 12000 rpm for 20 min, wash the precipitate with deionized water, and spray dry to obtain the enzyme-responsive nasal cooling composition. The degree of deacetylation of carboxymethyl chitosan is 85%, the molecular weight is 60 kDa, the dropping rate of the crosslinking agent is 0.7 mL / min, and the mass ratio of chitosan in the chitosan aqueous solution to sodium tripolyphosphate in the sodium tripolyphosphate aqueous solution is 5:1.

[0052] Example 2

[0053] An enzyme-responsive nasal cooling composition differs from Example 1 in that the degree of deacetylation of carboxymethyl chitosan is 60%. The carboxymethyl chitosan was adapted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0054] Example 3

[0055] An enzyme-responsive nasal cooling composition differs from Example 1 in that the degree of deacetylation of carboxymethyl chitosan is 95%, and the carboxymethyl chitosan is adaptively adjusted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0056] Example 4

[0057] An enzyme-responsive nasal cooling composition differs from Example 1 in that the molecular weight of carboxymethyl chitosan is 30 kDa. The carboxymethyl chitosan is adaptively adjusted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0058] Example 5

[0059] An enzyme-responsive nasal cooling composition differs from Example 1 in that the molecular weight of carboxymethyl chitosan is 100 kDa. The carboxymethyl chitosan is adaptively adjusted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0060] Comparative Example 1

[0061] An enzyme-responsive nasal cooling composition differs from Example 1 in that the degree of deacetylation of carboxymethyl chitosan is 40%, and the carboxymethyl chitosan is adaptively adjusted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0062] Comparative Example 2

[0063] An enzyme-responsive nasal cooling composition differs from Example 1 in that the degree of deacetylation of carboxymethyl chitosan is 98%, and the carboxymethyl chitosan is adaptively adjusted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0064] Comparative Example 3

[0065] An enzyme-responsive nasal cooling composition differs from Example 1 in that the molecular weight of carboxymethyl chitosan is 20 kDa. The carboxymethyl chitosan is adaptively adjusted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0066] Comparative Example 4

[0067] An enzyme-responsive nasal cooling composition differs from Example 1 in that the molecular weight of carboxymethyl chitosan is 150 kDa. The carboxymethyl chitosan is adaptively adjusted during the preparation process. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0068] The enzyme-responsive nasal cooling compositions prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to nasal cooling sensation tests, with a blank control group also included. The specific testing methods are as follows:

[0069] Preparation of blank control group: 0.300g of cooling agent WS-23 was added to 4.700g of 1,2-propanediol, followed by 5.000g of glycerol. The mixture was stirred at room temperature until dissolved and used as the blank control group. In other words, the chitosan in the blank control group was not encapsulated in the cooling agent WS-23; instead, the cooling sensation was tested directly using the cooling agent.

[0070] Preparation of experimental groups: 0.300g of the enzyme-responsive nasal cooling compositions prepared in Examples 1-5 and Comparative Examples 1-4 were weighed and added to 4.700g of 1,2-propanediol, followed by 5.000g of glycerin. The mixture was stirred at room temperature until dissolved to form the experimental groups. The blank control group and experimental groups were injected into the same type of e-cigarette cartridges, and evaluation was conducted after 30 minutes of core lubrication. The evaluation method was as follows: 20 rigorously trained evaluators were selected. Each evaluator first evaluated the blank control group, using this as a baseline, and then separately evaluated the experimental groups prepared from the enzyme-responsive nasal cooling compositions of Examples 1-5 and Comparative Examples 1-4. The evaluation criteria for nasal cooling intensity are shown in Table 1.

[0071] Table 1 Evaluation Criteria for Nasal Cavity Cooling Sensation Intensity

[0072] Intensity of cooling sensation in the nasal cavity Not cold Slightly cool cold It's very cool. Extremely cold Score 0～10 11～20 21～30 31～50 51～100

[0073] The cooling sensation test results of the experimental groups prepared from the enzyme-responsive nasal cooling compositions of Examples 1-5 and Comparative Examples 1-4 are shown in Table 2.

[0074] Table 2 Performance test results of Examples 1-5 and Comparative Examples 1-4

[0075]

[0076]

[0077] As shown in Table 2, the nasal cooling intensity value of the blank control group was 13, which was weak and the location of action was different. This indicates that when chitosan is not coated on the surface of the cooling agent, the cooling effect is not good. This is mainly because the cooling agent stays in the nasal cavity for a short time, thus affecting the cooling experience in the nasal cavity.

[0078] In Examples 1 and 3, the chitosan surface has a moderate number of free amino groups and a high surface charge density, making it easier for a sufficient quantity of cooling composition to bind stably and efficiently to the mucin in the nasal cavity, thus resulting in a stronger cooling effect. At the same time, the high degree of deacetylation of chitosan gives the enzyme-responsive nasal cooling composition excellent hydrophilicity, further promoting the rapid and efficient binding of cooling molecules to the nasal mucosa, resulting in a rapid cooling effect. Meanwhile, the encapsulation layer formed by chitosan with an appropriate molecular weight allows the cooling molecules to be released continuously at an appropriate rate, and a sufficient quantity of cooling composition further prolongs the duration of the cooling effect.

[0079] In Example 2, the degree of deacetylation was slightly lower than that in Example 1. On the one hand, the charge density on the surface of chitosan was slightly lower, which affected the rapid binding of the enzyme-responsive nasal cooling composition obtained in Example 2 to the nasal mucosa, and delayed the onset of cooling effect. On the other hand, the hydrophilicity of the enzyme-responsive nasal cooling composition was weakened, resulting in a reduction in the intensity and duration of cooling effect. Overall, the performance was moderate.

[0080] In Comparative Example 2, the chitosan had an excessively high deacetylation rate. The excessive free amino groups on the surface of chitosan weakened the effective electrostatic repulsion force after amino protonation, and the molecular chain entanglement of chitosan intensified, resulting in an overly dense coating layer. This hindered the diffusion of cooling molecules, affecting the onset speed and intensity of the cooling sensation. Furthermore, the excessive rigidity of the chitosan molecular chain made the coating layer prone to breakage, affecting the stability and duration of the cooling sensation of the enzyme-responsive nasal cooling composition. Therefore, the enzyme-responsive nasal cooling composition prepared in Comparative Example 2 had a weaker cooling sensation.

[0081] In Comparative Example 1, when the degree of deacetylation of chitosan was 40%, the surface charge of chitosan was insufficient, resulting in a weaker binding force between chitosan and the mucin in the nasal cavity. At the same time, the number of cooling components bound was also small, affecting the intensity and duration of the cooling sensation. In addition, the proportion of acetyl groups (-COCH3) in the chitosan molecular chain was relatively high, which made the enzyme-responsive nasal cooling composition more hydrophobic. Chitosan molecules were difficult to unfold quickly, which hindered the efficient binding of cooling molecules to the nasal mucosa. The cooling effect was slow, resulting in a weaker cooling sensation and a slower onset of action of the enzyme-responsive nasal cooling composition obtained in Comparative Example 1.

[0082] In Example 4, the carboxymethyl chitosan has a relatively small molecular weight and less steric hindrance, resulting in rapid diffusion of the enzyme-responsive nasal cooling composition. Chitosan is more easily dispersed in nasal mucus, has a rapid onset of action, and a strong cooling effect. However, the low molecular weight chitosan has a poor cross-linking effect and a slightly shorter coating time, which reduces the duration of the cooling effect.

[0083] In Example 5, the molecular weight of carboxymethyl chitosan is relatively large, resulting in a uniform and dense coating layer. This leads to a longer duration of cooling sensation. The high molecular diffusion resistance of the coating layer further prolongs the onset time of the cooling sensation.

[0084] In Comparative Example 3, the molecular weight of carboxymethyl chitosan was relatively small and the molecular chain was too short, resulting in a thin coating layer that was insufficient to maintain effective contact between the enzyme-responsive nasal cooling composition and the nasal mucosa. This resulted in a low cooling intensity, weak mucosal adhesion, and insufficient durability, leading to a very short duration of cooling sensation.

[0085] In Comparative Example 4, the molecular weight of carboxymethyl chitosan was as high as 150kDa, and the encapsulation layer formed was too dense. At the same time, the encapsulation layer formed by chitosan with an excessively large molecular weight was difficult to penetrate the mucosal barrier, which significantly prolonged the onset time of the cooling sensation and the intensity of the cooling sensation was relatively low.

[0086] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An enzyme-responsive nasal cooling composition, characterized in that, Includes a cooling agent and a coating layer covering the surface of the cooling agent; The coating layer comprises chitosan, which has a degree of deacetylation of 60% to 95% and a molecular weight of 30 to 100 kDa.

2. The enzyme-responsive nasal cooling composition as described in claim 1, characterized in that, The degree of deacetylation of the chitosan is 85%–95%, and the molecular weight is 60–100 kDa.

3. The enzyme-responsive nasal cooling composition as described in claim 1, characterized in that, The cooling agent includes one or more of L-menthol, L-menthone, piperonone, menthyl acetate, menthyl lactate, isomenthone, isomenthone, L-menthone glyceryl ketal, isomenthone acetate, menthyl succinate, camphor, 1,8-cineole, linalool, carvacrol, thymol, α-fungin, cooling agent Icillin, cooling agent WS-3, cooling agent WS-5, cooling agent WS-10, cooling agent WS-12, cooling agent WS-14, cooling agent WS-23, and cooling agent WS-27; and / or, The chitosan includes one or more of carboxymethyl chitosan, carboxyethyl chitosan, and hydroxypropyl chitosan.

4. A method for preparing an enzyme-responsive nasal cooling composition according to any one of claims 1 to 3, characterized in that, Includes the following steps: Step S10: Dissolve the cooling agent in an organic solvent to obtain a dispersion; Step S20: Add the dispersion to the chitosan aqueous solution, add the crosslinking agent solution, and then stir, centrifuge, wash and dry to obtain the enzyme-responsive nasal cooling composition.

5. The method for preparing the enzyme-responsive nasal cooling composition as described in claim 4, characterized in that, The crosslinking agent includes one or more of sodium tripolyphosphate, calcium chloride, sodium polyphosphate, glutaraldehyde, salicylaldehyde, isocyanate, tannic acid, and lysine; and / or, The organic solvent includes one or more of propylene glycol, ethanol, tricarboxylic acid glycerides, and lactic acid.

6. The method for preparing the enzyme-responsive nasal cooling composition as described in claim 4, characterized in that, In step S10, the concentration of the dispersion is 5% to 15% w / v; and / or, In step S20, the concentration of the chitosan aqueous solution is 1.0% to 3.0% w / v.

7. The method for preparing the enzyme-responsive nasal cooling composition as described in claim 4, characterized in that, Step S20 includes: adding the dispersion to the chitosan aqueous solution, adding a crosslinking agent solution dropwise while continuously stirring, controlling the pH of the system to be 4.0-5.0, stirring at room temperature for 50-70 min, adding alkali solution to adjust the pH to 5.5-6.5, centrifuging at 10000-14000 rpm for 10-30 min, washing the precipitate with deionized water, and spray drying to obtain the enzyme-responsive nasal cooling composition.

8. The method for preparing the enzyme-responsive nasal cooling composition as described in claim 7, characterized in that, In step S20, the dropping rate is 0.5 to 1 mL / min.

9. The method for preparing the enzyme-responsive nasal cooling composition as described in claim 7, characterized in that, The mass ratio of chitosan to the crosslinking agent in the chitosan aqueous solution is 4 to 6:

1.

10. A vaporized fragrance, characterized in that, The atomized fragrance includes the enzyme-responsive nasal cooling composition according to any one of claims 1 to 3, or the enzyme-responsive nasal cooling composition prepared by the method of preparing the enzyme-responsive nasal cooling composition according to any one of claims 4 to 9.

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