Preparation method of nicotine load and buccal nicotine product

Abstract

The invention provides a preparation method of a nicotine load. The preparation method comprises the following steps: S1, preparing porous silicon dioxide; s2, mixing a first solution containing nicotine with porous silicon dioxide, and then drying to obtain a nicotine-silicon dioxide compound; s3, mixing a second solution containing polydopamine with the nicotine-silicon dioxide compound, and then washing and drying to obtain a polydopamine modified compound; s4, mixing a third solution containing trypsin substrate polypeptide with an activating agent to obtain a polypeptide activating solution; mixing a polypeptide activating solution with the polydopamine modified compound, and then washing and freeze-drying to obtain drug-loaded microspheres; and S5, mixing the drug-loaded microspheres with the temperature-sensitive gel, and dispersing the drug-loaded microspheres in the temperature-sensitive gel to obtain the nicotine load. The invention also provides a nicotine buccal product.

Description

Technical Field

[0001] The present invention relates to the technical field of nicotine products, and in particular to a method for preparing a nicotine loading material and a nicotine oral product. Background Art

[0002] Nicotine oral products are a new type of smokeless tobacco product. Compared to traditional tobacco or e-cigarettes, they do not burn and produce smoke, so they do not cause secondary harm to the body when used. They can also be smoked in public places (such as on the subway) without disturbing others, making them convenient to use.

[0003] Nicotine pouches are a commonly used oral nicotine product. They are made by mixing nicotine with fillers, dispersants, lubricants, sweeteners, and other materials to form granules, which are then packaged in a non-woven bag. When a user uses the nicotine pouch, saliva in the mouth moistens the pouch, releasing the nicotine from the granules, which is then absorbed into the body through the oral mucosa.

[0004] However, due to the characteristics of the nicotine bag itself, there are problems such as uncontrollable nicotine release, short duration of action (generally most of the nicotine is quickly released in about 20-30 minutes), strong foreign body sensation in the mouth, and easy residue of composite particles in the mouth during use. Summary of the Invention

[0005] The present invention aims to provide a method for preparing a nicotine-loaded material. The nicotine-loaded material prepared by the method has the advantages of controllable nicotine release, long action time, good oral comfort, and low residue.

[0006] The present invention provides a method for preparing a nicotine loading material, comprising the following steps: S1: Preparation of porous silica; S2: mixing a first solution containing nicotine with the porous silica, so that the nicotine in the first solution adheres to the surface and pores of the porous silica, and then drying to obtain a nicotine-silica composite; S3: mixing a second solution containing polydopamine with the nicotine-silica composite, allowing the polydopamine in the second solution to adhere to the surface of the nicotine-silica composite, followed by washing and drying to obtain a polydopamine-modified composite; wherein the second solution is an alkaline solution; S4: mixing the third solution containing the trypsin substrate polypeptide with an activator to obtain a polypeptide activation solution; mixing the polypeptide activation solution with the polydopamine-modified complex to react the trypsin substrate polypeptide in the polypeptide activation solution with the polydopamine in the polydopamine-modified complex, followed by washing and lyophilization to obtain drug-loaded microspheres; S5: mixing the drug-loaded microspheres with the temperature-sensitive gel, so that the drug-loaded microspheres are dispersed in the temperature-sensitive gel to obtain a nicotine-loaded substance.

[0007] In one achievable manner, in the above step S1, the step of preparing the porous silica includes: mixing cetyltrimethylammonium bromide, polylactic acid microspheres and an ethanol-water mixture to obtain a first mixed solution; Simultaneously adding ethyl orthosilicate and aqueous ammonia to the first mixed solution and stirring while maintaining the pH at 10.5±0.2 to obtain a second mixed solution; The second mixed liquid is centrifuged and the precipitate in the second mixed liquid is collected; the precipitate is then washed, dried and calcined in sequence to obtain the porous silica.

[0008] In one achievable embodiment, the mass ratio of the hexadecyltrimethylammonium bromide to the tetraethyl orthosilicate is (0.15-0.2):1, and the mass ratio of the polylactic acid microspheres to the tetraethyl orthosilicate is (0.2-0.3):1.

[0009] In one achievable manner, the above step S2 specifically includes: The porous silica is placed in a vacuum desiccator, which is then evacuated; a first solution containing nicotine is injected into the vacuum desiccator, the vacuum desiccator is returned to normal pressure, and the desiccator is allowed to stand for a preset time to obtain a first mixture; and the first mixture is then dried under reduced pressure to obtain a nicotine-silicon dioxide composite.

[0010] In one achievable manner, in the above step S3, the second solution is a polydopamine-Tris buffer solution, and the pH of the polydopamine-Tris buffer solution is 8.0-9.0.

[0011] In one feasible manner, in the above-mentioned step S4, the third solution is a PBS solution of trypsin substrate polypeptide; the activator includes 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, and the molar ratio of the 1-ethyl-(3-dimethylaminopropyl)carbodiimide to the N-hydroxysuccinimide is 1:1.5.

[0012] In one achievable manner, in the above step S5, before mixing the drug-loaded microspheres with the temperature-sensitive gel, the drug-loaded microspheres are further subjected to an embedding treatment, and the embedding treatment specifically includes: preparing an aqueous phase solution and an oil phase solution; wherein the aqueous phase solution comprises sodium alginate, the drug-loaded microspheres, cell-penetrating peptides and water, and the oil phase solution comprises liquid paraffin and sorbitan oleate; The aqueous phase solution and the oil phase solution are mixed to form an emulsion; a fourth solution containing calcium ions is mixed with the emulsion to react on the surface of the drug-loaded microspheres to form a gel layer, thereby obtaining a second mixture; The second mixture is centrifuged, and the drug-loaded microspheres in the second mixture are collected; and then the drug-loaded microspheres are washed and freeze-dried.

[0013] In one achievable manner, the aqueous phase solution further comprises peppermint oil microemulsion.

[0014] In one achievable manner, in the above step S5, the step of preparing the temperature sensitive gel includes: Pluronic F127 is dissolved in deionized water, and then sodium hyaluronate and cell penetrating peptide are added. After mixing, the mixture is allowed to stand for degassing to obtain the temperature-sensitive gel.

[0015] The present invention also provides a nicotine oral product, comprising a nicotine loading material prepared by the above-mentioned method for preparing a nicotine loading material.

[0016] The method for preparing a nicotine-loaded material provided by the present invention uses porous silica as a carrier. Nicotine adheres to the surface and pores of the porous silica, making the nicotine release rate controllable, delaying the burst release of nicotine, and increasing the duration of nicotine action, thereby improving the user experience. Moreover, since nicotine is stored in the pores of the porous silica, the porous silica can provide a certain degree of protection for nicotine, protecting it from environmental factors and extending the shelf life of the product. At the same time, due to the high specific surface area of the porous silica, the porous silica can load more nicotine, thereby further increasing the duration of nicotine action.

[0017] At the same time, the nicotine-silica complex is modified with polydopamine. On the one hand, polydopamine can oxidize and self-polymerize under alkaline conditions to form a sticky polydopamine layer on the surface of the nicotine-silica complex. The catechol group in polydopamine can strongly adhere to the oral mucosa, so that the drug-loaded microspheres can adhere well to the oral mucosa during use, thereby allowing the human body to better absorb nicotine; on the other hand, polydopamine can provide an active site for the trypsin substrate polypeptide to attach to the surface of the nicotine-silica complex. That is, after the carboxyl group of the trypsin substrate polypeptide is activated by an activator, the carboxyl group of the trypsin substrate polypeptide can condense with the amino group of polydopamine to form an amide bond, thereby covalently coupling the trypsin substrate polypeptide to the surface of the nicotine-silica complex. Furthermore, since trypsin substrate polypeptide is attached to the surface of the nicotine-silica complex, the trypsin substrate polypeptide can lock nicotine on the porous silica. When the product is stored, it can reduce the separation of nicotine from the porous silica and play a certain protective role on nicotine, so that nicotine is protected from the influence of environmental factors and the shelf life of the product is extended. When the product is used, the trypsin in the mouth can specifically cleave the trypsin substrate polypeptide, so that the trypsin substrate polypeptide dissolves and releases nicotine, which does not affect the normal release of nicotine and can delay the sudden release of nicotine and increase the duration of nicotine action. At the same time, since the dissolution rate of the trypsin substrate polypeptide is affected by the pH environment of the mouth, the user can change the nicotine release rate by changing the pH of the mouth, thereby obtaining different nicotine release rates to meet the needs of different users.

[0018] At the same time, by mixing drug-loaded microspheres with temperature-sensitive gel, the product is in a gel-like form. The semi-solid gel is easy to apply to the gums and other places. Body temperature triggers the liquefaction and adhesion of the gel to avoid swallowing and displacement. Compared with traditional nicotine bags, the taste is more delicate and comfortable, without foreign body sensation, and almost no residue. DETAILED DESCRIPTION

[0019] Specific embodiments of the present invention are described in further detail below. The following examples illustrate the present invention but are not intended to limit its scope. The terms "first," "second," "third," "fourth," and so forth (if any) in the specification and claims of the present invention are used to distinguish similar items and are not necessarily used to describe a particular order or sequential sequence.

[0020] Nicotine pouches are a commonly used oral nicotine product. They are made by mixing nicotine with fillers, dispersants, lubricants, sweeteners, and other materials to form granules, which are then packaged in a non-woven bag. When a user uses the nicotine pouch, saliva in the mouth moistens the pouch, releasing the nicotine from the granules, which is then absorbed into the body through the oral mucosa.

[0021] However, there are the following problems with nicotine bags during use: 1. Since nicotine is attached to the surface of the filler, the release rate of nicotine is uncontrollable when the user uses the nicotine bag. After being moistened by saliva, the nicotine bag will release nicotine very quickly (that is, nicotine will quickly detach from the surface of the filler), so that the nicotine is released in a short time and the effect time is short (generally most of the nicotine is quickly released in about 20-30 minutes).

[0022] 2. When users use nicotine bags, the non-woven bag is in direct contact with the oral cavity, causing a foreign body sensation when holding the nicotine bag in the mouth. At the same time, since the composition particles in the non-woven bag will seep out from the pores of the non-woven bag and come into contact with the oral mucosa during use, and the composition particles are hard powder, this will further increase the foreign body sensation in the mouth. Moreover, the seeped composition particles will adhere to the inner wall of the oral cavity and are not easy to fall off, resulting in residue. Therefore, users usually need to rinse their mouths to remove the residue after holding the nicotine bag in their mouths, which affects the user experience.

[0023] To solve the above problems, an embodiment of the present invention provides a method for preparing a nicotine loading material, which is used in nicotine oral products. The method for preparing the nicotine loading material comprises the following steps: S1: preparing porous silica, which is a granular structure with pores; S2: mixing a first solution containing nicotine with the porous silica, causing the nicotine in the first solution to adhere to the surface and pores of the porous silica (i.e., the inner walls of the pores), followed by drying to obtain a nicotine-silica composite; wherein the nicotine-silica composite is in the form of granular microspheres, comprising porous silica and nicotine adhered to the surface and pores of the porous silica; S3: mixing a second solution containing polydopamine with the nicotine-silica complex, allowing the polydopamine in the second solution to adhere to the surface of the nicotine-silica complex, and then washing and drying to obtain a polydopamine-modified complex; wherein the second solution is an alkaline solution, the polydopamine-modified complex is a granular microsphere, and the polydopamine-modified complex includes the nicotine-silica complex and the polydopamine attached to the surface of the nicotine-silica complex; S4: mixing a third solution containing a trypsin substrate polypeptide with an activator to obtain a polypeptide activation solution; then mixing the polypeptide activation solution with the polydopamine-modified complex to react the trypsin substrate polypeptide in the polypeptide activation solution with the polydopamine in the polydopamine-modified complex, so that the trypsin substrate polypeptide in the polypeptide activation solution adheres to the surface of the polydopamine-modified complex; then washing and lyophilizing to obtain drug-loaded microspheres; wherein the drug-loaded microspheres are in a granular form, and the drug-loaded microspheres include the polydopamine-modified complex and the trypsin substrate polypeptide adhered to the surface of the polydopamine-modified complex; S5: Mixing and stirring the drug-loaded microspheres with the temperature-sensitive gel to disperse the drug-loaded microspheres in the temperature-sensitive gel to obtain a nicotine-loaded substance; wherein the temperature-sensitive gel is a gel that can be semi-solid at low temperatures (e.g., 4°C) and liquefy at high temperatures (e.g., body temperature).

[0024] In the above S2, the drying step after mixing the first solution with the porous silica is to remove excess first solution, thereby obtaining a nicotine-silica composite.

[0025] In the above S3, the washing and drying steps after mixing the second solution with the nicotine-silica complex are to remove excess second solution, thereby obtaining the polydopamine modified complex.

[0026] Among them, in the above S4, the washing step after mixing the polypeptide activation solution with the polydopamine modified complex is to remove excess polypeptide activation solution to obtain drug-loaded microspheres, and the freeze-drying step is to ensure the morphology of the drug-loaded microspheres (i.e., maintain the granular microsphere morphology) and make the polydopamine and trypsin substrate polypeptide adhere more tightly to prevent the polydopamine and trypsin substrate polypeptide from detaching from the drug-loaded microspheres.

[0027] In S4 above, the trypsin substrate polypeptide is an artificially designed short peptide chain with the sequence number GGRGKGG. Trypsin in the mouth can specifically recognize and cleave the trypsin substrate polypeptide (specifically, the cleavage position is GGR↓GKGG), thereby achieving the effect of releasing nicotine. The function of the activator is to activate the carboxyl group of the trypsin substrate polypeptide, allowing the carboxyl group of the trypsin substrate polypeptide to subsequently condense with the amino group of polydopamine to form an amide bond. At the same time, it enables the trypsin in the mouth to cleave the trypsin substrate polypeptide during subsequent use of the product.

[0028] The method for preparing a nicotine-loaded substance provided in an embodiment of the present invention uses porous silica as a carrier. Nicotine adheres to the surface and pores of the porous silica, making the nicotine release rate controllable and delaying the burst release of nicotine (because nicotine needs to be released from the pores of the porous silica, the nicotine release path is extended and the nicotine release rate is reduced). This increases the duration of nicotine action, thereby improving the user experience. Moreover, because nicotine is stored in the pores of the porous silica, the porous silica can provide a certain degree of protection for nicotine, protecting it from environmental factors and extending the shelf life of the product. At the same time, due to the high specific surface area of the porous silica, the porous silica can load more nicotine, thereby further increasing the duration of nicotine action.

[0029] At the same time, the nicotine-silica complex is modified with polydopamine. On the one hand, polydopamine can oxidize and self-polymerize under alkaline conditions to form a sticky polydopamine layer on the surface of the nicotine-silica complex. The catechol group in polydopamine can strongly adhere to the oral mucosa, so that the drug-loaded microspheres can adhere well to the oral mucosa during use, thereby allowing the human body to better absorb nicotine; on the other hand, polydopamine can provide an active site for the trypsin substrate polypeptide to attach to the surface of the nicotine-silica complex. That is, after the carboxyl group (-COOH) of the trypsin substrate polypeptide is activated by an activator, the carboxyl group of the trypsin substrate polypeptide can condense with the amino group (-NH2) of polydopamine to form an amide bond, thereby covalently coupling the trypsin substrate polypeptide to the surface of the nicotine-silica complex (that is, the trypsin substrate polypeptide is attached and fixed to the surface of the nicotine-silica complex by connecting with polydopamine). Furthermore, since the trypsin substrate polypeptide is attached to the surface of the nicotine-silica complex, the trypsin substrate polypeptide can lock the nicotine on the porous silica. When the product is stored, it can reduce or prevent the detachment of nicotine from the porous silica, and play a certain protective role on the nicotine, so that the nicotine is protected from the influence of environmental factors and the shelf life of the product is extended. When the product is used, the trypsin in the oral cavity can specifically cut the trypsin substrate polypeptide, so that the trypsin substrate polypeptide dissolves and releases the nicotine, which does not affect the normal release of nicotine and can delay the sudden release of nicotine and increase the duration of nicotine action (specifically, the trypsin substrate polypeptide is like a string attached to the microsphere). The surface of the porous silica locks the nicotine in the pores of the porous silica. When the product is used, the trypsin in the mouth can cut the peptide chain of the trypsin substrate polypeptide, thereby releasing nicotine. Since it takes a certain amount of time for trypsin to cut the peptide chain, the sudden release of nicotine can be avoided. At the same time, since the dissolution rate of the trypsin substrate polypeptide is affected by the pH environment of the mouth, the user can change the nicotine release rate by changing the pH of the mouth. For example, the user can drink acidic beverages to actively increase the nicotine release rate (the trypsin substrate polypeptide can be directly dissolved in an acidic environment, so it can increase the nicotine release rate), thereby obtaining different nicotine release rates to meet the needs of different users.

[0030] At the same time, by mixing the drug-loaded microspheres with a temperature-sensitive gel, the product takes on a gel-like form. The semi-solid gel is easily applied to areas like the gums. Body temperature triggers the gel to liquefy and adhere, preventing swallowing and displacement. Compared to traditional nicotine pouches, the taste is more delicate and comfortable, with no foreign body sensation and virtually no residue (this product is completely different from the nicotine pouch in form). Specifically, when the product is stored at low temperatures (e.g., 4°C), the temperature-sensitive gel becomes semi-solid at low temperatures, protecting and sealing the drug-loaded microspheres. During use, the user holds the product in the mouth, where the temperature-sensitive gel liquefies at body temperature and adheres to the inner wall of the mouth, releasing the drug-loaded microspheres and, in turn, the nicotine contained in them. Because the temperature-sensitive gel has a soft texture, it provides a good touch when in contact with the inner wall of the mouth, and there will be no foreign body sensation. At the same time, after use, the drug-loaded microspheres can be swallowed or spit out of the mouth along with the temperature-sensitive gel (after the product gradually releases nicotine in the mouth, the gel is dissolved by saliva or swallowed, and the drug-loaded microspheres can be swallowed along with the gel; among them, porous silica is almost harmless to the human body, so it can be swallowed), so there is almost no residue. At the same time, the temperature-sensitive gel can mask the chemical smell of nicotine, improving the user experience.

[0031] As an embodiment, in the above step S1, the particle size of the porous silica is 50-100 um.

[0032] As an embodiment, in the above step S1, the preparation step of the porous silica includes: (1) mixing cetyltrimethylammonium bromide (CTAB), polylactic acid microspheres (PLA) and an ethanol-water mixture to obtain a first mixed solution; (2) adding tetraethyl orthosilicate (TEOS) and ammonia water simultaneously to the first mixed solution and stirring, maintaining the pH at 10.5±0.2, to obtain a second mixed solution; (3) Centrifuging the second mixed solution and collecting the precipitate in the second mixed solution; then washing, drying and calcining the precipitate in sequence to obtain the porous silica.

[0033] Specifically, in the above steps, hexadecyltrimethylammonium bromide (mesoporous template) acts as a surfactant, which self-assembles into micelles and guides the condensation of tetraethyl orthosilicate around the micelles, with the hydrophilic ends of the micelles facing outward and the hydrophobic ends facing inward. Silica generated by the hydrolysis of tetraethyl orthosilicate is deposited on the micelle surfaces. After calcination, the micelles decompose and form a 2-5nm mesoporous structure within the porous silica. Polylactic acid microspheres (macroporous template) act as sacrificial templates. The polylactic acid microspheres are dispersed within the micelles, and silica is deposited on their surfaces. After calcination, the polylactic acid microspheres decompose and form 50-100nm through-hole macropores within the porous silica. Calcination is performed to decompose organic matter through high-temperature oxidation, that is, to completely remove the hexadecyltrimethylammonium bromide and polylactic acid microspheres, thereby retaining the porous structure and enhancing the skeleton stability of the porous silica. In this embodiment, porous silica with a hierarchical pore structure is prepared by a dual-template method. The macropores in the porous silica serve as drug reservoirs, which can increase the storage capacity of nicotine, and the mesopores can control the release rate of nicotine, thereby increasing the duration of nicotine action.

[0034] The above step (1) can specifically be: adding hexadecyltrimethylammonium bromide and polylactic acid microspheres to an ethanol-water mixture, and ultrasonically dispersing them for a period of time (for example, placing the above materials in an ultrasonic dispersing device, adjusting the ultrasonic dispersing device to a pulse mode, adjusting the power to 300 W, and dispersing for 30 minutes) to obtain a first mixed solution.

[0035] The above step (2) can be specifically as follows: heating the first mixed solution (for example, heating in a water bath at 35-45°C) and stirring (for example, by magnetic stirring, setting the rotation speed to 600 rpm), adding ethyl orthosilicate dropwise to the first mixed solution (dropping rate 0.5 mL / min), and simultaneously adding ammonia water (ammonia water concentration, for example, 25%-28%) to the first mixed solution, maintaining the pH of the first mixed solution at 10.5±0.2; stopping stirring after reacting for a period of time (for example, 6 hours), and then standing and aging for a period of time (for example, 24 hours) to obtain a second mixed solution.

[0036] The above step (3) can specifically be: placing the second mixed liquid in a centrifuge for centrifugal treatment (for example, setting the speed to 8000 rpm and centrifuging for 15 minutes), collecting the precipitate in the second mixed liquid, and then washing the precipitate with ethanol and deionized water three times respectively, and then drying the precipitate (for example, vacuum drying at 60°C for 12 hours), and then calcining the precipitate at a temperature of 450-650°C for 3-6 hours (heating rate of 2°C / min) to obtain porous silica.

[0037] As an embodiment, the particle size of the polylactic acid microspheres is 50 μm and the porosity is greater than 80%.

[0038] In one embodiment, the mass ratio of cetyltrimethylammonium bromide to tetraethyl orthosilicate is (0.15-0.2):1, and the mass ratio of polylactic acid microspheres to tetraethyl orthosilicate is (0.2-0.3):1. Too much cetyltrimethylammonium bromide can clog mesopores, while too little can reduce the number of mesopores. Too much polylactic acid microspheres can oversize and increase the number of macropores, thereby reducing the structural strength of the porous silica, while too little can result in blocked macropores.

[0039] In one embodiment, the volume ratio of ethanol to water in the ethanol-water mixture is 3:1 to 4:1. The purpose of using the ethanol-water mixture as a solvent is that ethanol dissolves the organosilicon source (TEOS), water promotes the hydrolysis of TEOS to form Si-OH groups, and the ethanol and water mix to form a homogeneous reaction system, avoiding phase separation. Ethanol regulates surface tension, reducing pore collapse during drying (more gentle than pure water), and water content influences the hydrolysis rate, thereby regulating pore size distribution (e.g., high water content tends to produce large pores). The volume ratio of tetraethyl orthosilicate to the ethanol-water mixture is (1-5):60.

[0040] As an implementation method, the above step S2 specifically includes: The porous silica is placed in a vacuum desiccator, which is then evacuated; a first solution containing nicotine is injected into the vacuum desiccator, the vacuum desiccator is returned to normal pressure, and the desiccator is allowed to stand for a preset time to obtain a first mixture; and the first mixture is then dried under reduced pressure to obtain a nicotine-silicon dioxide composite.

[0041] Specifically, in the above steps, the porous silica is vacuumed to expel air from the pores of the porous silica, resulting in a negative pressure. After returning to normal pressure, the first solution penetrates into the pores of the porous silica under the action of the pressure differential (i.e., the pores of the porous silica are under negative pressure, while the exterior of the porous silica is under normal pressure after returning to normal pressure, resulting in a pressure differential between the interior and exterior of the porous silica), thereby causing nicotine to adhere to the pores of the porous silica (i.e., this embodiment utilizes a vacuum impregnation method, utilizing the pressure differential between the interior and exterior of the porous silica to forcibly force the first solution into the pores, thereby increasing drug loading). Specifically, the above steps may include placing the porous silica in a vacuum desiccator, evacuating the vacuum desiccator to a pressure of -0.090 to 0.1 MPa, and maintaining the pressure for a period of time (e.g., 30 minutes); then rapidly injecting the first solution into the vacuum desiccator (rapid injection facilitates filling the pores of the porous silica with the first solution, reduces solvent volatilization, and prevents nicotine oxidation); then returning the vacuum desiccator to normal pressure and allowing the mixture to stand at room temperature (e.g., 25° C.) for 6-24 hours to obtain a first mixture; and then drying the first mixture under reduced pressure (e.g., at 40° C.) to obtain a nicotine-silica composite.

[0042] In one embodiment, the first solution is a nicotine-ethanol solution, i.e., the solvent in the first solution is ethanol, and the concentration of the first solution is 30% w / v, meaning that 1 mL of the first solution contains 0.3 g of nicotine. The w / v (mass / volume) ratio of porous silica to the first solution is 1:10, meaning that 1 g of porous silica is added to 10 mL of the first solution. Of course, in other embodiments, the first solution may also use other solvents, such as isopropyl alcohol, methanol, or acetone.

[0043] In one embodiment, in step S3, the second solution is a polydopamine-Tris (i.e., tris(hydroxymethyl)aminomethane) buffer solution, i.e., the solvent in the second solution is a Tris buffer solution, and the pH of the polydopamine-Tris buffer solution is 8.0-9.0. The mass percentage concentration of the polydopamine-Tris buffer solution is 0.1%-1%, and the w / v ratio of the nicotine-silica complex to the polydopamine-Tris buffer solution is 1:(50-100), i.e., 1 g of nicotine-silica complex is added to 50-100 mL of polydopamine-Tris buffer.

[0044] As an implementation method, the above step S3 specifically includes: The nicotine-silica complex is added to the second solution containing polydopamine, and the mixture is shaken in an oscillator for a period of time (for example, the oscillation frequency of the oscillator is set to 150 rpm and the mixture is shaken at 25° C. for 4 hours). The mixture is then placed in a centrifuge for centrifugal washing (for example, the rotation speed is set to 5000 rpm and the mixture is washed three times with a detergent for 5 minutes each time. The detergent can be deionized water, etc.), and then dried at 40° C. to obtain a polydopamine-modified complex.

[0045] As one embodiment, in step S4 above, the third solution is a PBS solution of the trypsin substrate polypeptide, i.e., the solvent in the third solution is a PBS solution (PBS solution is also known as phosphate buffer solution, generally prepared using Na2HPO4 and KH2PO4), and the pH of the third solution is 7.4. The activator includes 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS), and the molar ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide to N-hydroxysuccinimide is 1:1.5. The concentration of the PBS solution of the trypsin substrate polypeptide is 0.5-1 mg / mL, and the mass ratio of the activator to the third solution is 1:1. The w / v ratio of the polydopamine-modified complex to the polypeptide activation solution is 1:50, i.e., 1 g of the polydopamine-modified complex is added to 50 mL of the polypeptide activation solution.

[0046] As an implementation method, the above step S4 specifically includes: A 0.5-1 mg / mL PBS solution of a trypsin substrate polypeptide is prepared, and then an activator is added to the PBS solution of the trypsin substrate polypeptide, wherein the activator includes EDC and NHS at a molar ratio of 1:1.5, and the activation reaction is performed for a period of time (e.g., 30 minutes) to obtain a polypeptide activation solution; then the polydopamine-modified complex is added to the polypeptide activation solution, reacted for a period of time (e.g., at 4°C for 12 hours), and then placed in a centrifuge for centrifugal washing (e.g., set the speed to 5000 rpm, use a detergent to wash 3 times, each time for 5 minutes, the detergent can be deionized water, etc.), and then freeze-dried to obtain drug-loaded microspheres; wherein the freeze-drying process can include: pre-freezing at -50°C for 2 hours, freeze-drying at -20°C for 24 hours, and desorption at 25°C for 4 hours.

[0047] As an embodiment, in the above step S5, before mixing the drug-loaded microspheres with the temperature-sensitive gel, the drug-loaded microspheres are further subjected to an embedding treatment, and the embedding treatment specifically includes: (a) preparing an aqueous solution and an oily solution; wherein the aqueous solution comprises sodium alginate, the drug-loaded microspheres, a cell-penetrating peptide (CPP), and water, and the oily solution comprises liquid paraffin and sorbitan oleate (i.e., Span 80, a lipophilic nonionic surfactant); (b) mixing the aqueous phase solution and the oil phase solution to form an emulsion; mixing a fourth solution containing calcium ions with the emulsion to react on the surface of the drug-loaded microspheres to form a gel layer, thereby obtaining a second mixture; (c) centrifuging the second mixture and collecting the drug-loaded microspheres in the second mixture; then washing and freeze-drying the drug-loaded microspheres.

[0048] Specifically, in the above-mentioned encapsulation treatment step, sodium alginate in the aqueous solution coats the drug-loaded microspheres, and then the sodium alginate undergoes a cross-linking reaction with calcium ions to form a hydrogel network, that is, a gel layer is formed on the surface of the drug-loaded microspheres. The gel layer not only has the effect of delaying the burst release of nicotine (in oral products, nicotine needs to pass through the gel layer to diffuse and release), but also has a protective effect on the drug-loaded microspheres. At the same time, it can mask the chemical smell of nicotine, thereby improving the user experience. At the same time, because the aqueous solution contains cell-penetrating peptides (cell-penetrating peptides are also called cell-penetrating peptides. Cell-penetrating peptides are a type of short peptide that can carry macromolecules into cells; in this embodiment, the sequence of the cell-penetrating peptide is GRKKRRQRRRPPQ), the formed gel layer contains cell-penetrating peptides. The cell-penetrating peptides can disrupt the tight junctions between mucosal epithelial cells and promote the transmembrane transport of nicotine, that is, promote the absorption of nicotine by the human body, improve the absorption efficiency of nicotine by the human body, and thus improve the user experience.

[0049] As an embodiment, in the above step (a), the aqueous phase solution further comprises peppermint oil microemulsion. The addition of peppermint oil microemulsion can enhance the cooling sensation of the product, thereby improving the taste and flavor of the product.

[0050] As one embodiment, in step (a) above, the aqueous phase solution comprises, by mass percentage, 1%-3% sodium alginate, 3%-20% drug-loaded microspheres, 0.3%-0.6% cell-penetrating peptide, 1%-5% peppermint oil microemulsion, with the remainder being water; the oil phase solution comprises 0.5%-1% sorbitan oleate, with the remainder being liquid paraffin. In step (b) above, the fourth solution is a calcium chloride solution, with a concentration of 5%.

[0051] As an implementation method, the above step (a) may specifically be: preparing an aqueous phase solution: mixing sodium alginate, drug-loaded microspheres, cell-penetrating peptide, peppermint oil microemulsion, and water in appropriate proportions to obtain an aqueous phase solution; Prepare the oil phase solution: mix liquid paraffin and sorbitan oleate in proportion to obtain an oil phase solution.

[0052] As an implementation manner, the above step (b) may specifically be: The oil phase solution is heated and stirred (heating temperature 40°C, stirring speed 300 rpm), and the aqueous phase solution is added dropwise to the oil phase solution (dropping rate 0.3 mL / min) to form an emulsion (in this step, the ratio of the aqueous phase solution to the oil phase solution is not limited, and generally, the solution is added dropwise until an emulsion is formed); then, a 5% calcium chloride solution is added to the emulsion, with the volume ratio of the calcium chloride solution to the emulsion generally being 1:1, and a cross-linking reaction is allowed to proceed for a period of time (e.g., 30 minutes) to obtain a second mixture.

[0053] As an implementation manner, the above step (c) may specifically be: The second mixture is centrifuged in a centrifuge (e.g., at 4000 rpm for 10 minutes). The drug-loaded microspheres in the second mixture are collected and then washed three times with petroleum ether. The drug-loaded microspheres are then lyophilized. The lyophilization process may include pre-freezing at -50°C for 2 hours, lyophilizing at -20°C for 24 hours, and desorption at 25°C for 4 hours. Washing the drug-loaded microspheres removes residual emulsion, and lyophilizing the drug-loaded microspheres maintains their morphology and allows for tighter adhesion of the gel layer, preventing the gel layer from detaching from the drug-loaded microspheres.

[0054] As an embodiment, in the above step S5, the temperature sensitive gel is Pluronic F127 gel (i.e., Pluronic F127 gel), and the steps of preparing the temperature sensitive gel include: Pluronic F127 (a commercially available nonionic surfactant with a molecular weight of 12,600 Da) was dissolved in deionized water, and then sodium hyaluronate and cell-penetrating peptide were added. After mixing, the mixture was allowed to stand for degassing to obtain the temperature-sensitive gel.

[0055] Specifically, by adding cell-penetrating peptides to the temperature-sensitive gel, the cell-penetrating peptides can destroy the tight junctions between mucosal epithelial cells, promote the transmembrane transport of nicotine, improve the human body's absorption efficiency of nicotine, and thereby improve the user experience.

[0056] As an embodiment, the temperature-sensitive gel comprises, by mass percentage, 10%-20% Pluronic F127, 1%-5% sodium hyaluronate, 0.3%-0.6% cell-penetrating peptide, and the remainder is deionized water.

[0057] As an embodiment, the specific preparation steps of the temperature sensitive gel include: Dissolve 10%-20% Pluronic F127 in cold deionized water (the temperature of deionized water is 4°C) and stir until transparent; then add 1%-5% sodium hyaluronate and 0.3%-0.6% cell-penetrating peptide, mix well, and then stand at 4°C to degas. The temperature-sensitive gel is obtained.

[0058] As an implementation method, the above step S5 specifically includes: Add the drug-loaded microspheres to the temperature-sensitive gel at a mass ratio of 1:5. Vortex mix the mixture (2000 rpm for 5 minutes) to disperse the drug-loaded microspheres throughout the temperature-sensitive gel to obtain the nicotine-loaded substance. The nicotine-loaded substance can then be stored in pre-cooled aluminum tubes (at 4°C).

[0059] The following examples generally illustrate the steps for preparing the nicotine loading material: 1. Preparation of porous silica support (dual template method) 1.1 Template solution preparation: 0.5-2 g of hexadecyltrimethylammonium bromide and 0.5-3 g of polylactic acid microspheres were added to 60 mL of an ethanol-water mixture (the volume ratio of ethanol to water was 3:1), and ultrasonically dispersed for 30 minutes (power 300 W, pulse mode) to obtain a first mixed solution.

[0060] 1.2 Sol-gel reaction: The first mixed solution was transferred to a three-necked flask, heated in a water bath at 40°C, and magnetically stirred (rotation speed 600 rpm). 1-5 mL of ethyl orthosilicate (dropping rate 0.5 mL / min) was added dropwise to the first mixed solution. Simultaneously, 0.5-2 mL of ammonia water (ammonia water concentration of 25%-28%) was added dropwise to the first mixed solution to maintain the pH of the first mixed solution at 10.5. After reacting for 6 hours, stirring was stopped, and the mixture was allowed to stand for aging for 24 hours to obtain a second mixed solution.

[0061] 1.3 Post-processing: The second mixed liquid was placed in a centrifuge for centrifugation at a speed of 8000 rpm for 15 minutes, and the precipitate in the second mixed liquid was collected. The precipitate was then washed three times with ethanol and three times with deionized water respectively. The precipitate was then dried at 60° C. under vacuum for 12 hours, and then calcined at 450-650° C. for 3-6 hours (heating rate of 2° C. / min) to obtain porous silica.

[0062] 2. Nicotine Loading and Surface Modification 2.1 Vacuum impregnation drug loading: The porous silica was placed in a vacuum desiccator, which was then evacuated to a pressure of -0.090-0.1 MPa and maintained for 30 minutes. 10 mL of a nicotine-ethanol solution (30% w / v) was rapidly injected into the vacuum desiccator, and the vacuum desiccator was then returned to normal pressure and allowed to stand at 25°C for 6-24 hours to obtain a first mixture. The first mixture was then dried under reduced pressure at 40°C to a constant weight to obtain a nicotine-silica composite.

[0063] 2.2 Modification of polydopamine adhesion layer: The nicotine-silica complex was added to 0.1%-1% polydopamine-Tris buffer (pH 8.0-9.0), shaken in an oscillator at 25°C for 4 hours (oscillation frequency 150 rpm), then placed in a centrifuge for centrifugal washing (speed 5000 rpm, washed 3 times with deionized water, each for 5 minutes), and then dried at 40°C to obtain a polydopamine-modified complex.

[0064] 2.3 Enzyme-responsive peptide chain coupling: A 0.5-1 mg / mL PBS solution (pH 7.4) of a trypsin substrate polypeptide (sequence GGRGKGG) was prepared, and then an activator was added to the PBS solution of the trypsin substrate polypeptide, wherein the activator included EDC and NHS at a molar ratio of 1:1.5, and the mass ratio of the activator to the PBS solution of the trypsin substrate polypeptide was 1:1. The activation reaction was carried out for 30 minutes to obtain a polypeptide activation solution; the polydopamine-modified complex was added to the polypeptide activation solution, and the w / v ratio of the polydopamine-modified complex to the polypeptide activation solution was 1:50. The reaction was carried out at 4°C for 12 hours, and then the solution was placed in a centrifuge for centrifugal washing (speed 5000 rpm, washed 3 times with deionized water, each time for 5 minutes), and then freeze-dried (pre-freezing at -50°C for 2 hours, freeze-drying at -20°C for 24 hours, and desorption at 25°C for 4 hours) to obtain drug-loaded microspheres.

[0065] 3. Preparation of Microsphere-Gel Composite System 3.1 Sodium alginate microsphere embedding: Prepare an aqueous phase solution: mix 1%-3% sodium alginate, 3%-20% drug-loaded microspheres, 0.3%-0.6% cell penetrating peptide, 1%-5% peppermint oil microemulsion, and water in proportion to obtain an aqueous phase solution; Prepare the oil phase solution: mix liquid paraffin and 0.5%-1% sorbitan oleate in proportion to obtain an oil phase solution.

[0066] The oil phase solution was heated and stirred (heating temperature 40°C, stirring speed 300 rpm), and the aqueous phase solution was added dropwise to the oil phase solution (dropping rate 0.3 mL / min) to form an emulsion; then, a 5% calcium chloride solution was added to the emulsion, with a volume ratio of calcium chloride solution to emulsion of 1:1, and the cross-linking reaction was carried out for 30 minutes to obtain a second mixture.

[0067] The second mixture was placed in a centrifuge for centrifugation (4000 rpm, 10 minutes), the drug-loaded microspheres in the second mixture were collected, and then the drug-loaded microspheres were washed 3 times with petroleum ether, and then freeze-dried (pre-freezing at -50°C for 2 hours, freeze-drying at -20°C for 24 hours, and desorption at 25°C for 4 hours).

[0068] 3.2 Preparation of temperature sensitive gel: Dissolve 10%-20% Pluronic F127 in cold deionized water (the temperature of deionized water is 4°C) and stir until transparent; then add 1%-5% sodium hyaluronate and 0.3%-0.6% cell-penetrating peptide, mix well, and then stand at 4°C to degas. The temperature-sensitive gel is obtained.

[0069] 3.3 Microsphere-gel composite: The drug-loaded microspheres were added to the temperature-sensitive gel at a mass ratio of 1:5. The mixture was then vortex-mixed using a vortex mixer (2000 rpm, 5 minutes) to disperse the drug-loaded microspheres in the temperature-sensitive gel to obtain a nicotine load. The nicotine load was then filled into a pre-cooled aluminum tube (the pre-cooled aluminum tube temperature was 4°C) for storage.

[0070] An embodiment of the present invention further provides a nicotine loading material, which is prepared by the above-mentioned method for preparing a nicotine loading material.

[0071] An embodiment of the present invention further provides a nicotine oral product, comprising a nicotine loading material prepared by the above-described method for preparing a nicotine loading material.

[0072] The advantages of the nicotine loading material prepared in this embodiment include: 1. Porous silica is used as a carrier, and a multi-level porous silica structure is prepared through a double-template method. The macropores in the porous silica act as drug reservoirs, which can increase the storage capacity of nicotine. The mesopores can control the release rate of nicotine, which not only increases the duration of nicotine action, but also provides users with a better user experience through controlled release of nicotine.

[0073] 2. Using porous silica as a carrier, nicotine is stored in the pores of porous silica. Porous silica can protect nicotine to a certain extent, protecting nicotine from the influence of environmental factors, extending the shelf life of the product, ensuring the stability of the product effect, and allowing users to obtain a consistent nicotine experience during use.

[0074] 3. Porous silica is used as a carrier. Due to its high specific surface area, porous silica can load more nicotine, thereby further increasing the duration of nicotine action (the duration of action of this product can reach about 4 hours).

[0075] 4. Trypsin substrate polypeptide coupling is used. Trypsin substrate polypeptide can lock nicotine on porous silica. When the product is stored, it can reduce or prevent nicotine from detaching from porous silica, and play a certain protective role on nicotine, so that nicotine is protected from the influence of environmental factors and the shelf life of the product is extended. Moreover, when in use, under normal oral pH, the trypsin in the mouth specifically cuts the trypsin substrate polypeptide to achieve stable release of nicotine. At the same time, users can change the nicotine release rate by changing the oral pH. For example, users can drink acidic beverages to actively increase the nicotine release rate, achieve more complex nicotine release, enhance product experience, and meet the needs of different users.

[0076] 5. By adding cell-penetrating peptides, cell-penetrating peptides can destroy the tight junctions between mucosal epithelial cells and promote the transmembrane transport of nicotine, that is, promote the human body's absorption of nicotine, improve the human body's absorption efficiency of nicotine, and thus improve the user experience.

[0077] 6. By mixing drug-loaded microspheres with temperature-sensitive gel, the product is in a gel-like form. The semi-solid gel is easy to apply to the gums and other places. Body temperature triggers the gel to liquefy and adhere, avoiding swallowing and displacement. It is not only convenient to use, but also has a more delicate and comfortable taste than traditional nicotine bags, without any foreign body sensation, and almost no residue.

[0078] Example 1 1. Preparation of porous silica support (dual template method) 1.1 Template solution preparation: 0.8 g of hexadecyltrimethylammonium bromide and 1.2 g of polylactic acid microspheres were added to 60 mL of an ethanol-water mixture (the volume ratio of ethanol to water was 3:1), and ultrasonically dispersed for 30 minutes (power 300 W, pulse mode) to obtain a first mixed solution.

[0079] 1.2 Sol-gel reaction: The first mixed solution was transferred to a three-necked flask, heated in a water bath at 40°C, and magnetically stirred (rotation speed 600 rpm). 5 mL of ethyl orthosilicate was added dropwise to the first mixed solution (dropping rate 0.5 mL / min). Simultaneously, 2 mL of ammonia water (ammonia concentration 28%) was added dropwise to the first mixed solution to maintain the pH of the first mixed solution at 10.5. After reacting for 6 hours, stirring was stopped, and the mixture was allowed to stand for aging for 24 hours to obtain a second mixed solution.

[0080] 1.3 Post-processing: The second mixed liquid was placed in a centrifuge for centrifugal treatment at a speed of 8000 rpm for 15 minutes. The precipitate in the second mixed liquid was collected, and then the precipitate was washed three times with ethanol and deionized water respectively. The precipitate was then dried and vacuum-dried at 60°C for 12 hours. The precipitate was then calcined at 550°C for 4 hours (heating rate of 2°C / min) to obtain porous silica.

[0081] 2. Nicotine Loading and Surface Modification 2.1 Vacuum impregnation drug loading: The porous silica was placed in a vacuum desiccator, which was then evacuated to -0.095 MPa and maintained for 30 minutes. 10 mL of a nicotine-ethanol solution (30% w / v) was quickly injected into the vacuum desiccator, and the vacuum desiccator was then restored to normal pressure and allowed to stand at 25°C for 12 hours to obtain a first mixture. The first mixture was then dried under reduced pressure at 40°C to a constant weight to obtain a nicotine-silica composite.

[0082] 2.2 Modification of polydopamine adhesion layer: The nicotine-silica complex was added to 0.2% polydopamine-Tris buffer (pH 8.5), shaken in an oscillator at 25°C for 4 hours (oscillation frequency 150 rpm), then placed in a centrifuge for centrifugal washing (speed 5000 rpm, washed 3 times with deionized water, each for 5 minutes), and then dried at 40°C to obtain a polydopamine-modified complex.

[0083] 2.3 Enzyme-responsive peptide chain coupling: A 1 mg / mL trypsin substrate polypeptide (sequence GGRGKGG) PBS solution (pH 7.4) was prepared, and then an activator was added to the PBS solution of the trypsin substrate polypeptide. The activator included EDC and NHS at a molar ratio of 1:1.5, and the mass ratio of the activator to the PBS solution of the trypsin substrate polypeptide was 1:1. The activation reaction was carried out for 30 minutes to obtain a polypeptide activation solution. The polydopamine-modified complex was added to the polypeptide activation solution, and the w / v ratio of the polydopamine-modified complex to the polypeptide activation solution was 1:50. The reaction was carried out at 4°C for 12 hours, and then placed in a centrifuge for centrifugal washing (speed 5000 rpm, washed 3 times with deionized water, each time for 5 minutes), and then freeze-dried (pre-freezing at -50°C for 2 hours, freeze-drying at -20°C for 24 hours, and desorption at 25°C for 4 hours) to obtain drug-loaded microspheres.

[0084] 3. Preparation of Microsphere-Gel Composite System 3.1 Sodium alginate microsphere embedding: Prepare an aqueous phase solution: Mix 2% sodium alginate, 10% drug-loaded microspheres, 0.5% cell-penetrating peptide, 1% peppermint oil microemulsion, and 86.5% water in appropriate proportions to obtain an aqueous phase solution; Prepare the oil phase solution: mix 99.5% liquid paraffin and 0.5% sorbitan oleate in proportion to obtain an oil phase solution.

[0085] The oil phase solution was heated and stirred (heating temperature 40°C, stirring speed 300 rpm), and the aqueous phase solution was added dropwise to the oil phase solution (dropping rate 0.3 mL / min) to form an emulsion; then, a 5% calcium chloride solution was added to the emulsion, with a volume ratio of calcium chloride solution to emulsion of 1:1, and the cross-linking reaction was carried out for 30 minutes to obtain a second mixture.

[0086] The second mixture was placed in a centrifuge for centrifugation (4000 rpm, 10 minutes), the drug-loaded microspheres in the second mixture were collected, and then the drug-loaded microspheres were washed 3 times with petroleum ether, and then freeze-dried (pre-freezing at -50°C for 2 hours, freeze-drying at -20°C for 24 hours, and desorption at 25°C for 4 hours).

[0087] 3.2 Preparation of temperature sensitive gel: Dissolve 20% Pluronic F127 in cold deionized water (the temperature of the deionized water is 4°C) and stir until transparent; then add 1% sodium hyaluronate and 0.5% cell-penetrating peptide, mix well, and then stand at 4°C to degas. The temperature-sensitive gel is obtained.

[0088] 3.3 Microsphere-gel composite: The drug-loaded microspheres were added to the temperature-sensitive gel at a mass ratio of 1:5. The mixture was then vortex-mixed using a vortex mixer (2000 rpm, 5 minutes) to disperse the drug-loaded microspheres in the temperature-sensitive gel to obtain a nicotine load. The nicotine load was then filled into a pre-cooled aluminum tube (the pre-cooled aluminum tube temperature was 4°C) for storage.

[0089] Performance testing: 1. Enzyme responsiveness test (1) Sample preparation: Experimental Group 1: Weigh 50 mg of the drug-loaded microspheres prepared in step 2.3 above (the final nicotine loading was not used for testing to eliminate the effect of the gel on the nicotine release rate and to confirm whether the drug-loaded microspheres can be released by enzyme triggering to ensure the effectiveness of the basic function) and disperse them in 50 mL of PBS solution. Then, add 0.1 mg / mL (i.e., 5 mg) of trypsin.

[0090] Control group 1: 50 mg of the drug-loaded microspheres prepared in step 2.3 above were weighed and dispersed in 50 mL of PBS solution without adding trypsin.

[0091] The two solutions were transferred to a constant temperature water bath shaker and pre-warmed to 37°C.

[0092] (2) Timed sampling: At 15, 30, and 60 minutes, respectively, 1 mL of solution was aspirated from the experimental group 1 and the control group 1 using a microsampler (and 1 mL of fresh PBS solution was added at the same time). The samples were filtered through a 0.22 μm filter membrane, and the filtrate was used for HPLC (high performance liquid chromatography) detection to calculate the cumulative nicotine release rate of the experimental group 1 and the control group 1 at each time point.

[0093] The cumulative nicotine release rates of experimental group 1 and control group 1 at various time points are shown in the following table:

[0094] As can be seen from the table above, the cumulative nicotine release rate of experimental group 1 over a 30-minute period was 25.6%, which is 3.6 times the cumulative nicotine release rate of control group 1. This indicates that trypsin can effectively trigger the release of nicotine (trypsin can specifically cleave trypsin substrate polypeptides, causing them to dissolve and release nicotine). When users take the product sublingually, they can obtain sufficient nicotine in a timely manner, meeting the demand for rapid onset of action. At the same time, compared to conventional nicotine pouches, the nicotine pouch quickly releases most of the nicotine in about 20-30 minutes (the nicotine pouch releases more than 50% of the nicotine in about 30 minutes, and can even reach 70%-90%). Therefore, compared to nicotine pouches, this product can delay the sudden release of nicotine and prolong the duration of nicotine's effect.

[0095] 2. pH response test (1) Sample preparation: Experimental Group 2: 50 mg of the drug-loaded microspheres prepared in step 2.3 above were weighed and dispersed in 50 mL of medium solution 1, where medium solution 1 was artificial saliva (containing 0.2% mucin) and the pH of medium solution 1 was 6.8.

[0096] Experimental Group 3: 50 mg of the drug-loaded microspheres prepared in step 2.3 above were weighed and dispersed in 50 mL of medium solution 2. Medium solution 2 consisted of artificial saliva + citric acid (i.e., medium solution 2 was medium solution 1 with citric acid added). The pH of medium solution 2 was 5.0.

[0097] The two solutions were transferred to a constant temperature water bath shaker and pre-warmed to 37°C.

[0098] (2) Timed sampling: At 5, 15, 30, and 60 minutes, 1 mL of solution was drawn from Experimental Group 2 and Experimental Group 3 using a microsampler (and 1 mL of fresh PBS solution was added at the same time). The samples were filtered through a 0.22 μm filter membrane, and the filtrate was used for HPLC (high performance liquid chromatography) detection to calculate the cumulative nicotine release rate of Experimental Group 2 and Experimental Group 3 at each time point.

[0099] The cumulative nicotine release rates of experimental groups 2 and 3 at various time points are shown in the following table:

[0100] As can be seen from the table above, the cumulative nicotine release rate of Experimental Group 2 over 30 minutes was 24.1%, completing the main nicotine release phase and in line with actual user habits (Experimental Group 2 simulates the user's normal oral environment, pH 6.8). The cumulative nicotine release rate of Experimental Group 3 over 30 minutes was 58.6%, 2.4 times that of Experimental Group 2, indicating that the nicotine release rate can be increased in an acidic environment (the pH of Experimental Group 3 was 5.0, an acidic environment, and the trypsin substrate peptide can directly dissolve in an acidic environment, thereby increasing the nicotine release rate). In actual use, users can change the nicotine release rate by changing the oral pH (for example, users can actively increase the nicotine release rate by drinking acidic beverages), thereby meeting the needs of different users.

[0101] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a nicotine loading material, characterized in that: The following steps are involved: S1: Preparation of porous silica; S2: mixing a first solution containing nicotine with the porous silica, so that the nicotine in the first solution adheres to the surface and pores of the porous silica, and then drying to obtain a nicotine-silica composite; S3: mixing a second solution containing polydopamine with the nicotine-silica composite, allowing the polydopamine in the second solution to adhere to the surface of the nicotine-silica composite, followed by washing and drying to obtain a polydopamine-modified composite; wherein the second solution is an alkaline solution; S4: mixing the third solution containing the trypsin substrate polypeptide with an activator to obtain a polypeptide activation solution; mixing the polypeptide activation solution with the polydopamine-modified complex to react the trypsin substrate polypeptide in the polypeptide activation solution with the polydopamine in the polydopamine-modified complex, followed by washing and lyophilization to obtain drug-loaded microspheres; S5: mixing the drug-loaded microspheres with the temperature-sensitive gel, so that the drug-loaded microspheres are dispersed in the temperature-sensitive gel to obtain a nicotine-loaded substance.

2. The method for preparing a nicotine loading material according to claim 1, wherein: In the above step S1, the preparation steps of the porous silica include: mixing cetyltrimethylammonium bromide, polylactic acid microspheres and an ethanol-water mixture to obtain a first mixed solution; Simultaneously adding ethyl orthosilicate and aqueous ammonia to the first mixed solution and stirring while maintaining the pH at 10.5±0.2 to obtain a second mixed solution; The second mixed liquid is centrifuged and the precipitate in the second mixed liquid is collected; the precipitate is then washed, dried and calcined in sequence to obtain the porous silica.

3. The method for preparing a nicotine loading material according to claim 2, wherein: The mass ratio of the hexadecyltrimethylammonium bromide to the tetraethyl orthosilicate is (0.15-0.2):1, and the mass ratio of the polylactic acid microspheres to the tetraethyl orthosilicate is (0.2-0.3):

1.

4. The method for preparing a nicotine loading material according to claim 1, wherein: The above step S2 specifically includes: The porous silica is placed in a vacuum desiccator, which is then evacuated; a first solution containing nicotine is injected into the vacuum desiccator, the vacuum desiccator is returned to normal pressure, and the desiccator is allowed to stand for a preset time to obtain a first mixture; and the first mixture is then dried under reduced pressure to obtain a nicotine-silicon dioxide composite.

5. The method for preparing a nicotine loading material according to claim 1, wherein: In the above step S3, the second solution is a polydopamine-Tris buffer solution, and the pH of the polydopamine-Tris buffer solution is 8.0-9.

0.

6. The method for preparing a nicotine loading material according to claim 1, wherein: In the above step S4, the third solution is a PBS solution of the trypsin substrate polypeptide; the activator includes 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, and the molar ratio of the 1-ethyl-(3-dimethylaminopropyl)carbodiimide to the N-hydroxysuccinimide is 1:1.

5.

7. The method for preparing a nicotine loading material according to claim 1, wherein: In the above step S5, before the drug-loaded microspheres are mixed with the temperature-sensitive gel, the drug-loaded microspheres are further subjected to an embedding treatment, and the embedding treatment specifically includes: preparing an aqueous phase solution and an oil phase solution; wherein the aqueous phase solution comprises sodium alginate, the drug-loaded microspheres, cell-penetrating peptides and water, and the oil phase solution comprises liquid paraffin and sorbitan oleate; The aqueous phase solution and the oil phase solution are mixed to form an emulsion; a fourth solution containing calcium ions is mixed with the emulsion to react on the surface of the drug-loaded microspheres to form a gel layer, thereby obtaining a second mixture; The second mixture is centrifuged, and the drug-loaded microspheres in the second mixture are collected; and then the drug-loaded microspheres are washed and freeze-dried.

8. The method for preparing a nicotine loading material according to claim 7, wherein: The aqueous phase solution also includes peppermint oil microemulsion.

9. The method for preparing a nicotine loading material according to any one of claims 1 to 8, wherein: In the above step S5, the steps of preparing the temperature sensitive gel include: Pluronic F127 is dissolved in deionized water, and then sodium hyaluronate and cell penetrating peptide are added. After mixing, the mixture is allowed to stand for degassing to obtain the temperature-sensitive gel.

10. A nicotine oral product, characterized in that: The nicotine loading material is prepared by the method for preparing a nicotine loading material according to any one of claims 1 to 9.

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