A finishing method for oral nicotine products and the manufacturing process of oral nicotine products

Abstract

This invention discloses a post-processing method and a manufacturing process for oral nicotine products. The post-processing method includes the following steps: obtaining a newly produced first nicotine product with a moisture content lower than the target moisture content at the factory; loading a predetermined quantity of the first nicotine product into a pre-placed sealed container; placing a humidification pack inside the sealed container and then sealing the container; storing the sealed container at room temperature to allow the first nicotine product to rehydrate to the target moisture content within a preset time range to form a second nicotine product, while maintaining the water activity within the sealed container within a preset water activity range. Without changing the factory moisture content standard of the nicotine product, the initial moisture content of the formula is reduced during the production and packaging stage to improve production capacity and packaging qualification rate; the rehydration to the target value within several days after sealing reduces overall manufacturing costs and consistency risks.

Description

Technical Field

[0001] This invention relates to the field of nicotine product manufacturing technology, and in particular to a post-processing method and manufacturing process for oral nicotine products. Background Technology

[0002] Nicotine lozenges are a new type of smokeless tobacco product. Compared to traditional tobacco or e-cigarettes, they do not burn and produce smoke, thus causing no secondary harm to the body. They can also be used in public places (such as on the subway) without disturbing others, making them convenient. Nicotine pouches are a commonly used type of nicotine lozenge. They are made by mixing nicotine with fillers, dispersants, lubricants, sweeteners, and other materials to form granules or powder, which are then packaged in a non-woven fabric pouch. When using a nicotine pouch, saliva in the mouth moistens the pouch, releasing the nicotine from the granules and allowing it to be absorbed into the body through the oral mucosa.

[0003] Nicotine pouches, as oral nicotine products, are highly sensitive to moisture content and water activity: too low a moisture content results in slow onset of action, a dry taste, and powdering; too high a moisture content easily leads to dripping, increased irritation, unstable flavor, and increased risks to microbial and chemical stability. Current manufacturing processes for oral nicotine products directly set the target moisture content during the formulation and pouch-making stages. This lengthens the process cycle, reduces packaging qualification rates, and high moisture content easily leads to adhesion and clumping, further deviating due to temperature and humidity fluctuations during transportation and storage. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the current nicotine product manufacturing process, the present invention provides a post-processing method and a manufacturing process for oral nicotine products, which can reduce the initial moisture content of the formula during the production and packaging stage without changing the moisture content standard of the nicotine product at the factory, thereby improving production capacity and packaging qualification rate; after sealing, the moisture content returns to the target value within a few days, reducing the overall manufacturing cost and consistency risk.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] A finishing method for use in the manufacturing process of oral nicotine products, the finishing method comprising the following steps:

[0007] Obtain a newly produced first nicotine product, the moisture content of which is lower than the target moisture content at the factory;

[0008] The predetermined quantity of the first nicotine product is packed into a pre-prepared sealed container;

[0009] After placing a humidity regulating pack inside the sealed container, the sealed container is then sealed.

[0010] The sealed container is stored at room temperature, allowing the first nicotine product to rehydrate to the target water content within a preset time range to form the second nicotine product, while maintaining the water activity in the sealed container within a preset water activity range.

[0011] According to one aspect of the present invention, the preset water activity is 0.8 to 0.95, and the fluctuation at 25°C does not exceed ±0.03.

[0012] According to one aspect of the invention, the ambient temperature is 15~35°C.

[0013] According to one aspect of the present invention, the preset time range is 1 to 7 days.

[0014] According to one aspect of the present invention, the water content of the first nicotine product is 5 to 25 percent lower by mass than that of the second nicotine product.

[0015] According to one aspect of the invention, the water activity of the humidification pack is determined based on the target water content at the factory.

[0016] According to one aspect of the present invention, the humidity regulating pack includes a humidity regulating composition and a covering structure, the covering structure including at least one side of a moisture-permeable but liquid-impermeable functional membrane, the moisture-permeable but liquid-impermeable functional membrane satisfying a water vapor transmission rate of 1000-3000 g·m at 25°C and 85% relative humidity. -2 ·d -1 .

[0017] According to one aspect of the invention, the loading amount of the humidity-regulating composition in the humidity-regulating package and the water vapor transmission rate of the moisture-permeable but liquid-impermeable functional membrane are selected such that the time to reach half of the rewetting progress is 48-96 hours and the steady-state fluctuation of water activity is ≤±0.03.

[0018] According to one aspect of the present invention, the encapsulation structure is a directional slow-release structure that is barrier on one side and permeable to moisture on the other, including a barrier surface and a permeable surface. The barrier surface is a low-permeability, high-barrier material fixedly attached to the inner surface of the sealed container, and the permeable surface is a permeable but liquid-impermeable functional membrane.

[0019] A manufacturing process for oral nicotine products, the manufacturing process for oral nicotine products including the post-processing method applied as described above in the manufacturing process for oral nicotine products.

[0020] Advantages of implementing this invention:

[0021] 1. Maintaining a preset water activity essentially constant within the target temperature range, and slowly releasing moisture into dry nicotine products at a controlled rate, achieving coupled control of "constant aw and moisture recovery," extending shelf life and maintaining a stable experience. Constant aw + slow moisture release dual control: Quantitatively replenishing water to the nicotine pouch without altering the aw ensures a stable product experience and controllable microbial / chemical risks.

[0022] 2. Without altering the finished nicotine product's moisture content standard, the initial moisture content of the formula can be reduced during the production and packaging stages to improve production capacity and packaging qualification rate. After sealing, the moisture content will automatically return to the target value within a few days using this humidification pack, reducing overall manufacturing costs and consistency risks. Increased production capacity and yield: Allows nicotine bags to operate with lower moisture content during bag making / canning, reducing adhesion and clumping, and increasing equipment capacity and packaging qualification rate per unit time; the cans automatically return to the finished product standard after sealing. Shelf life and consistency: Two-way humidification maintains stable aw (aw rate) within the can, improving fluctuations during cross-climate transport and storage; reduces top / bottom variations within the same can and batch / inter-batch differences. Customizable parameters: aw rate, wVTR, and humidification pack dosage can be customized according to the optimal window for different brands / flavors / strengths. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments 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 these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the finishing method applied to the manufacturing process of oral nicotine products according to the present invention;

[0025] Figure 2 This is a schematic cross-sectional view of a humidity regulating bag structure according to the present invention;

[0026] Figure 3 This is a schematic diagram of the arrangement of the humidity control pack, nicotine bag, and can as described in this invention;

[0027] Figure 4 This is a schematic diagram of the asymmetric humidity control package structure with single-sided barrier and single-sided moisture permeability as described in this invention, and its attachment in the tank. Detailed Implementation

[0028] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a finishing method applied to the manufacturing process of oral nicotine products includes the following steps:

[0030] Step S1: Obtain the first nicotine product with a newly produced moisture content lower than the target moisture content at the factory.

[0031] Step S1, obtaining the newly produced first nicotine product, wherein the moisture content of the first nicotine product is lower than the target moisture content at the factory, includes: obtaining the first nicotine product, i.e., the nicotine bag, through a conventional nicotine bag production process. In practical applications, actual examples of nicotine bag production processes can be found in the processes of manufacturers such as Superouse.

[0032] Production process flow reference:

[0033] 1. Weighing;

[0034] Accurately weigh the nicotine composition (containing nicotine, sugar alcohols, pH adjusters, etc.) according to product requirements (such as flavor, coolness, sweetness, etc.).

[0035] 2. Granulation;

[0036] Materials such as powders and molten liquids are processed into granules using wet granulation, dry granulation, one-step granulation, or spray granulation technologies. Among these, wet granulation is the most widely used.

[0037] 3. Bag making;

[0038] Using non-woven fabric material, the feeding speed is controlled by a photoelectric positioning device to fill the granules into a flat bag that is sealed on three sides.

[0039] In this embodiment, during the granulation and bag-making processes of the conventional production process described above, the moisture content of the relevant nicotine composition of the granules is reset to be lower than the original factory-determined moisture content standard. The goal is to obtain nicotine bags with a moisture content lower than the factory target by adjusting the key parameters of the conventional production process, thus laying the foundation for the uniformity and stability of subsequent rewetting (avoiding uneven moisture distribution and mold risk caused by excessively high initial moisture content, or excessively low initial moisture content leading to a slow rewetting speed).

[0040] In practical applications, the following details may be included:

[0041] Parameter adjustments for conventional production processes:

[0042] Weighing process: According to product specifications (such as nicotine content of 10mg / tablet, mint flavor), accurately weigh the nicotine composition (e.g., nicotine tartrate 2.5%, xylitol 55%, mannitol 25%, citric acid 1%, menthol 0.5%, microcrystalline cellulose 16%), ensuring that the component ratio error is ≤0.1% (using an electronic balance with an accuracy of 0.001g).

[0043] Granulation process: Wet granulation is used (the most widely used method, suitable for viscous materials). The concentration of binder (hydroxypropyl methylcellulose, HPMC) solution is adjusted (from the conventional 15% to 10%), and the amount added is reduced (from 10% to 7%). After granulation, the particles are dried in a fluidized bed dryer (temperature 40-45℃, air velocity 0.8-1.0m / s) for 30-45 minutes to reduce the moisture content of the particles from the conventional 12%-15% to 8%-10% (using a rapid moisture analyzer with an accuracy of 0.1%).

[0044] Bag making process: Food-grade non-woven fabric (such as polyester / viscose fiber blend, 25g / ㎡, air permeability 100-150mm / s) is used, and granules are filled by photoelectric positioning automatic bag making machine (feeding speed 30-50 pieces / minute) to ensure that the weight error of each piece is ≤0.05g (using online weighing system to reject unqualified products in real time); after bag making, metal detector is used to detect and prevent foreign objects from being mixed in.

[0045] Verification of low moisture content:

[0046] 100 nicotine pouches were randomly selected and their moisture content was tested (e.g., average moisture content 8.5%, standard deviation 0.2%) to ensure that the moisture content of all samples was lower than the target moisture content of 15%-20% (the target moisture content of the factory is set at 13%-16%, so the moisture content of the first nicotine product is controlled at 8%-11%).

[0047] Taking a Superouse "Icy Mint" nicotine bag as an example, its standard target moisture content is 14%. In step S1, by extending the drying time of the granulation process by 15 minutes (from 30 minutes to 45 minutes), the moisture content of the granules is reduced to 9%. The moisture content of the first nicotine bag obtained after bag making is 8.8%, which meets the low moisture content requirement.

[0048] Step S2: Pack the predetermined quantity of the first nicotine product into a pre-prepared sealed container;

[0049] According to the actual packaging specifications and requirements, the predetermined quantity of the first nicotine product is packed into the pre-prepared sealed container.

[0050] For example, a canister can be selected as the sealed container.

[0051] The goal is to pack low-moisture nicotine bags into sealed containers with high oxygen and moisture barrier properties to ensure that the external environment (oxygen and moisture) does not interfere with the internal humidity control system during the subsequent rehumidification process.

[0052] In practical applications, the following processes may be included:

[0053] First, the choice of a sealed container:

[0054] Material: Prioritize aluminum foil composite bags (PET / AL / PE structure, oxygen barrier ≤ 0.5 cm³ / m²·24h·atm, moisture barrier ≤ 0.5 g / m²·24h) or food-grade plastic containers (PP material, with silicone sealing ring, leakage rate ≤ 0.5 g / m²·24h after sealing). ).

[0055] Specifications: Select the container size according to the number of nicotine pouches (e.g., 100ml aluminum foil pouch for 20 tablets / pouch; 200ml PP can for 50 tablets / can), ensuring that 15%-20% headspace is reserved in the container to provide space for moisture diffusion of the humidifier pack.

[0056] Secondly, the loading operation specifications:

[0057] An automatic bagging machine (speed 60-80 pieces / minute) is used to fill nicotine bags into containers to avoid contamination caused by human contact (such as hand oils and bacteria); 10 containers are randomly selected from each batch of products to check the integrity of the nicotine bags (no damage to the non-woven fabric and no cracks in the seal) to ensure that the defect rate is ≤0.1%.

[0058] Example for reference:

[0059] A certain brand (such as "Zyn") uses a 10-piece aluminum foil bag packaging specification. The container size is 100mm×60mm×15mm, and the headspace volume is about 20ml. During filling, the quantity of each bag is detected by photoelectric sensors to ensure that there is no underfilling or overfilling.

[0060] Step S3: After placing the humidity regulating pack inside the sealed container, seal the sealed container;

[0061] The humidity regulating pack includes a humidity regulating composition and a coating structure. The coating structure includes at least one moisture-permeable but liquid-impermeable functional membrane. The moisture-permeable but liquid-impermeable functional membrane satisfies a water vapor transmission rate (WVTR) of 1000-3000 g·m³ at 25°C and 85% relative humidity. -2 ·d -1 .

[0062] In practical applications, the loading amount of the humidity-regulating composition in the humidity-regulating package and the water vapor transmission rate of the moisture-permeable but liquid-impermeable functional membrane are selected such that the time to reach half of the rewetting progress is 48-96 hours and the steady-state fluctuation of water activity is ≤±0.03.

[0063] In practical applications, the coating structure is a directional slow-release structure with one side blocking moisture and the other side permeable to moisture. It includes a barrier surface and a permeable surface. The barrier surface is a low-permeability, high-barrier material fixedly attached to the inner surface of the sealed container, and the permeable surface is a moisture-permeable but liquid-impermeable functional membrane. The coating structure can be asymmetric lamination: the side closest to the tank wall is a low-permeability, high-barrier material (such as an aluminum foil composite / high-barrier coating membrane, with a WVTR ≤ 2 g·m³ at 25°C and 85% RH). -2 ·d -1 It is attached to the bottom or inside of the can, using methods such as hot melt adhesive, pressure-sensitive adhesive, heat-sealing dots, or friction matching. The other side is a moisture-permeable but water-impermeable food-grade functional membrane (WVTR 1000-3000g·m). -2 ·d -1 For example, microporous polyolefin / hydrophilically modified TPU / composite membranes (meeting the requirements for water tightness under hydrostatic pressure or water ingress pressure). This reduces moisture loss through the tank wall to the outside. The asymmetric structure achieves directional moisture release: water vapor preferentially targets the internal head space and nicotine pouch, inhibiting ineffective diffusion to the plastic tank wall and the outside, preventing moisture from diffusing out of the plastic tank, reducing moisture loss, and maintaining the long-term stability of the internal moisture reservoir and the target air pressure (AW).

[0064] Both the barrier and the breathable surfaces are made of food-safe materials and ink / adhesive systems, making them suitable for direct or indirect contact scenarios with nicotine bags.

[0065] The humidification pack is preferably fixed to the bottom / inside of the can by means of "annular adhesive channel", "dot matrix heat sealing" or "mechanical buckle" to form a stable interface and avoid displacement.

[0066] Each can contains 20 bags and a 5g humidification packet, which can achieve rehydration within a few days after filling at 25℃ and maintain the target water activity (aw) and moisture content range within a 12-month shelf life.

[0067] In this embodiment, step S3 is the core step in achieving nicotine product rewetting and water activity control. It requires directional slow-release structure design, humidity adjustment parameter matching, and sealing operation to ensure the rewetting effect and stability.

[0068] Specifically, the implementation process includes the following:

[0069] 1. Humidity regulating pack directional sustained-release structure design (asymmetric lamination):

[0070] The humidification pack employs an asymmetric laminated structure of "barrier surface + permeable surface" to achieve directional release of water vapor into the can while preventing moisture loss through the can wall, thus improving humidification efficiency. The barrier surface (near the can wall) uses an aluminum foil / polyethylene (Al / PE) composite film (30μm thick) with a water vapor transmission rate (WVTR) ≤1g·m⁻²·d⁻¹ (25℃, 85%RH), exhibiting excellent moisture and oxygen barrier properties. It is attached to the center of the inner side of the can lid using food-grade adhesive (avoiding obstruction of the permeable surface), ensuring complete adhesion between the barrier surface and the can wall, blocking the path of moisture diffusion from the humidification pack to the outside of the can. The permeable side (facing the inside of the tank) is made of modified polylactic acid (PLA) permeable membrane (25 μm thick, with 10% polyethylene glycol (PEG) added as a plasticizer), with a WVTR of 2000 g·m⁻²·d⁻¹ (25℃, 85%RH), meeting the requirements of 1000-3000 g·m⁻²·d⁻¹. This membrane has the characteristics of being permeable to moisture but impermeable to liquid (water contact angle ≥90°), which can prevent leakage of the humidification composition, while allowing water vapor to be efficiently transferred into the tank.

[0071] like Figures 2 to 4 As shown, the humidity control pack includes:

[0072] A humidity-regulating substrate 1, comprising a humidity-regulating composition, wherein the humidity-regulating composition is used to maintain the water activity within a preset temperature range within a preset water activity range in a sealed container; the humidity-regulating composition is cured by a gel or porous carrier and does not release free liquid at 40°C.

[0073] and a packaging material covering the moisture-regulating substrate, wherein at least one side of the packaging material is a moisture-permeable but liquid-impermeable functional membrane, and the moisture-permeable but liquid-impermeable functional membrane satisfies a water vapor transmission rate of 1000-3000 g·m at 25°C and 85% relative humidity. -2 ·d -1 The packaging material includes a barrier layer 3 and a moisture-permeable layer 2 disposed opposite to each other. The moisture-regulating substrate is disposed between the barrier layer and the moisture-permeable layer. The barrier layer is made of a low-moisture-permeable, high-barrier material, and the moisture-permeable layer is a moisture-permeable but liquid-impermeable functional membrane. The low-moisture-permeable, high-barrier material satisfies a water vapor transmission rate ≤2 g·m³ at 25°C and 85% relative humidity. -2 ·d -1 The moisture-permeable but liquid-impermeable functional membrane is a microporous polyolefin, hydrophilic modified TPU, or a multilayer composite membrane.

[0074] When the bidirectional humidity control pack works in conjunction with the nicotine product within a sealed container, it can slowly release and transfer moisture to the nicotine product at a controlled rate until a set equilibrium is reached, while maintaining a substantially constant baseline water activity within the sealed container. The preset water activity is 0.8~0.95, and its fluctuation at 25°C does not exceed ±0.03.

[0075] In practical applications, the humidity-regulating composition can employ a polymer gel system, utilizing the vast network structure of hydrophilic polymers to absorb and lock in moisture, regulating moisture absorption and release through their hydrophilic-hydrophobic balance. The polymer molecular chains contain hydrophilic groups (such as -OH, -COOH), which can capture water molecules through hydrogen bonds. The physical structure of the gel network determines its moisture absorption and release kinetics. When the ambient humidity is high, the polymer network absorbs water and swells. When the ambient humidity is low, the moisture within the polymer network is released, and the network shrinks. The equilibrium humidity is determined by the type and concentration of the polymer. Common gel materials: Natural polymers: agar, sodium alginate, gelatin, carrageenan. Semi-synthetic / synthetic polymers: Sodium carboxymethyl cellulose (CMC-Na): commonly used and safe. Hydroxypropyl methylcellulose (HPMC): good film-forming properties. Sodium polyacrylate (PAAS): extremely absorbent (up to hundreds of times its own weight), but its moisture control precision is not as good as salt. Polyvinyl alcohol (PVA): good film-forming properties and high strength. Moisturizers (adjusting water activity): Glycerin, propylene glycol, sorbitol. These can reduce water activity, making the composition's water activity lower than that of pure water (water activity = 1.0), thus enabling the release of moisture into drier environments.

[0076] 2. Matching of moisture conditioning composition with moisture permeability parameters:

[0077] The moisture-conditioning composition must meet the requirements for moisture release capacity and water activity control. Its loading amount and moisture-permeable membrane parameters need to be optimized through experiments to ensure that the rewetting progress and steady-state fluctuations meet the standards.

[0078] For example, an optional moisture-conditioning composition formulation can be used: a ternary system of sodium carboxymethyl cellulose (CMC-Na) + glycerol + water (mass ratio 3:2:5), where CMC-Na acts as a water-retaining agent, glycerol adjusts water activity, and water acts as a moisture-releasing medium. By adjusting the glycerol content, the initial water activity of the moisture-conditioning composition is set to 0.70 (higher than the target water activity of 0.65), ensuring that it has the driving force to release moisture into the product.

[0079] Loading quantity determined: For each can containing 20 sachets of nicotine product (1g per sachet, total mass 20g), with an initial moisture content of 8% (dry basis) and a target moisture content of 12% (dry basis), the amount of water to be absorbed is:

[0080]

[0081] The moisture release rate of the conditioning composition (the percentage of moisture released when the water activity decreases from 0.70 to 0.65) is approximately 16% (determined experimentally), therefore the loading amount must meet the following requirements:

[0082] (m_{\text{humidifier pack}}=\frac{\Deltam}{f}=\frac{0.8g}{16%}=5g / can);

[0083] The final determined moisture-conditioning packaging capacity was 5g / can, which met the requirements of the procedure.

[0084] Optimization of moisture permeability parameters: The WVTR and area of ​​the moisture permeable membrane determine the moisture release rate. Through experiments, when the moisture permeable surface area is 0.005㎡ (the moisture conditioning pack size is 5cm×10cm, and the moisture permeable surface is unobstructed), a modified PLA membrane with a WVTR of 2000g·m⁻²·d⁻¹ can achieve the following:

[0085] Initial moisture release rate (when the water activity in the tank is 0.50):

[0086] (2000g·m⁻²·d⁻¹\times0.005㎡=10g / d) (due to high driving force and fast speed);

[0087] Half the soaking time (absorbing 0.4g of water, which is half the required amount of water):

[0088] 72 hours (3 days), which meets the requirement of 48-96 hours (if the moisture permeability is too high, such as 3000g·m⁻²·d⁻¹, the half-time of rewetting will be shortened to 48 hours;

[0089] If the moisture permeability is too low, such as 1000 g·m⁻²·d⁻¹, the rewetting time will be extended to 96 hours, which is within the allowable range.

[0090] 3. Humidity pack arrangement and sealing operation:

[0091] Placement method: Attach the humidifier packet to the center of the inside of the can lid using food-grade self-adhesive, ensuring that the barrier surface is in complete contact with the can lid (to prevent moisture from escaping through the gaps in the can lid), and that the permeable surface faces inward (to avoid being blocked by the product, which would affect the transfer of water vapor).

[0092] Sealing operation: Use aluminum screw-cap cans (capacity 100mL, can wall thickness 0.2mm), the can opening is equipped with a food-grade rubber sealing ring (compression rate 20%), the can cap is tightened by a screw capping machine (torque 1.5N·m) to ensure that the air tightness inside the can is ≤0.5mL / min@10kPa (tested by a leak tester), to prevent outside air and humidity from entering the can and affecting the humidity conditioning effect.

[0093] Step S4: Store the sealed container at room temperature to allow the first nicotine product 4 to rehydrate to the target water content within a preset time range to form the second nicotine product, and keep the water activity in the sealed container within a preset water activity range.

[0094] The preset water activity range is 0.8 to 0.95, and the fluctuation at 25°C does not exceed ±0.03.

[0095] In practical applications, the ambient temperature is 15~35℃.

[0096] In practical applications, the preset time range is 1 to 7 days.

[0097] In practical applications, the water content of the first nicotine product is 5 to 25 percent lower than that of the second nicotine product.

[0098] In practical applications, the water activity of the humidification pack is determined based on the target water content at the factory.

[0099] Step S4 is a crucial stage in achieving the transition of nicotine products from a "dry state" to a "target moisture content." It requires maintaining stable product quality through ambient temperature control, monitoring the rewetting process, and ensuring steady-state water activity. In this embodiment, the specific implementation process may include:

[0100] Storage conditions at room temperature:

[0101] The sealed container must be stored in a normal temperature warehouse at 25±2℃ and relative humidity of 40%-60%, meeting the following requirements:

[0102] Temperature control: Avoid high temperatures (>30℃) that cause a decline in the performance of the humidity-conditioning membrane (e.g., PLA membranes will soften at high temperatures, WVTR will increase, and the moisture release rate will be too fast); avoid low temperatures (<10℃) that cause a decrease in the fluidity of the humidity-conditioning composition (e.g., CMC-Na solution will gel at low temperatures, affecting water vapor transfer).

[0103] Humidity control: The relative humidity of the warehouse needs to be stable (40%-60%) to avoid extreme humidity (such as >70%), which would cause the water vapor pressure outside the tank to be higher than inside the tank (which may enter through the tank gaps and affect the water activity balance); avoid excessively low humidity (<30%), which would cause the water vapor inside the tank to dissipate rapidly (which would require the humidifier to release more moisture and increase the load consumption).

[0104] Monitoring and Examples of the Regeneration Process:

[0105] To maintain a soft texture and mucosal compatibility, the target water activity for oral tobacco is set at 0.90 (within the 0.8-0.95 range, balancing microbial control and sensory quality). It is initially dry (for ease of storage and transportation), with an initial moisture content of 5% and a target moisture content of 18% (requiring higher humidity to maintain softness). The humidification pack employs a directional slow-release design (a barrier surface prevents external moisture intrusion, while a permeable surface controls the rate of moisture release), with an initial water activity of 0.98 (higher than the target water activity, providing continuous moisture release). The packing weight matches the total mass of the oral tobacco (e.g., 20g humidification pack per 100g of oral tobacco, WVTR = 1.2g / kg). (To ensure slow and even moisture transfer). As shown in Table 1:

[0106] Table 1:

[0107]

[0108] Water activity steady-state maintenance and mechanism (core of shelf-life quality stability):

[0109] After rehydration (day 5), the tank enters a dynamic equilibrium state (water activity of both the humidification pack and oral flue gas is 0.90). During the shelf life (18 months), water activity fluctuations are ≤±0.03 (example data: 0.87-0.93). The maintenance mechanism is as follows:

[0110] Dynamic equilibrium principle: When the water activity in the can is lower than the target (e.g., due to slight leakage of the packaging, a small amount of moisture is lost from the cigarette in the mouth, and the water activity in the can drops to 0.87), the water activity of the humidifier pack (0.90) is higher than that in the can, and it will release moisture in a directional manner through the moisture-permeable membrane (driving force = 0.90 - 0.87 = 0.03), causing the water activity in the can to rise back to 0.90; when the water activity in the can is higher than the target (e.g., due to infiltration from a high humidity environment, the water activity in the can rises to 0.93), the water activity of the humidifier pack (0.90) is lower than that in the can, and it will absorb excess moisture in the can (driving force = 0.93 - 0.90 = 0.03), causing the water activity to drop to 0.90.

[0111] Examples of shelf-life stability (18-month quality assurance):

[0112] Accelerated testing (35℃, 75%RH, equivalent to 18 months at room temperature) verified that the quality indicators of the oral tobacco were stable.

[0113] Moisture stability: 17%-19% (target 18%, fluctuation ≤ ±1%);

[0114] Water activity fluctuation: 0.87-0.93 (≤±0.03, meeting the requirements of 0.8-0.95 range);

[0115] Microbial control: Microbial limit ≤100 CFU / g (0.90 water activity can inhibit most pathogenic bacteria (such as Salmonella, which requires >0.95), but molds must be strictly controlled (the minimum growth water activity for molds is about 0.85, and 0.87 is just at the inhibition boundary, so the fluctuation range must be strictly limited)).

[0116] Sensory and efficacy: Nicotine retention rate ≥95% (smoking in the mouth is absorbed through the mucous membrane, and high retention rate ensures stable efficacy); the taste remains soft and moist, without dryness or stickiness.

[0117] Key Mechanism Explanation (Core Logic for Ensuring Process Effectiveness):

[0118] The importance of the half-moistening time (60 hours): The half-moistening time for oral tobacco is set at 60 hours (that is, the time required to reach the target half-moisture content). If the moistening is too fast (<36 hours), the surface will quickly absorb water and expand to form a "water film", which will hinder the transfer of internal moisture and result in "sticky on the outside and dry on the inside" (sticky on the surface and dry and hard on the inside, affecting the chewing experience). If the moistening is too slow (>144 hours), the waiting time from purchase to consumption is too long (e.g., dry oral tobacco needs to be left for 5 days to reach the best taste), which reduces the product's competitiveness.

[0119] Significance of steady-state water activity (0.90±0.03):

[0120] Sensory quality: A water activity of 0.90 keeps the smoke in the mouth soft and elastic; below 0.87 it becomes dry, hard and brittle (unchewable); above 0.93 it becomes sticky and stringy (affecting oral comfort).

[0121] Microbial safety: The fluctuation range of 0.90±0.03 keeps the water activity within the mold inhibition boundary (mold needs >0.85 to grow, and 0.87 can effectively inhibit it), while avoiding excessive bacterial proliferation due to excessively high water activity (>0.95);

[0122] Stable efficacy: Stable water activity prevents nicotine from evaporating due to dryness (water activity < 0.85) or degrading due to moisture (water activity > 0.95), ensuring a nicotine retention rate of ≥ 95%.

[0123] Through directional sustained-release humidification pack design (barrier surface + permeable surface, controlling the direction and rate of moisture release) and precise parameter matching (humidification pack load = oral tobacco mass × target moisture content difference × 1.2 (safety factor), WVTR = 0.8-1.5g / L), To ensure slow and even moisture transfer, and with strict sealing (using aluminum-plastic composite film packaging, moisture permeability ≤0.5g / L), To prevent external humidity from intruding, combined with ambient temperature control (storage temperature 15-25℃ to avoid high temperature accelerating moisture transfer), monitoring of the rehydration process (regular testing of water content and water activity to ensure compliance with time requirements), and steady-state maintenance of water activity (dynamic balance mechanism), the oral tobacco achieves precise control from "dry state (5% water content)" to "target state (18% water content, 0.90 water activity)," and ensures stable quality within an 18-month shelf life (water content, water activity, microorganisms, and nicotine retention all meet standards).

[0124] Application example of this embodiment:

[0125] The finishing process for a certain brand of nicotine pouches (taking 10,000 pouches / batch as an example):

[0126] 1. Adjust the HPMC solution concentration to 10% during granulation; the moisture content of the dried granules is 9.0%.

[0127] 2. After bag making, 10,000 nicotine pouches are obtained, and 20 pouches are packed into one aluminum foil pouch (500 pouches in total).

[0128] 3. Place one 2g potassium chloride humidifier packet in each aluminum foil bag and heat-seal.

[0129] 4. After being stored at 22℃ and 55%RH for 48 hours, the moisture content was 13.5% and the water activity was 0.84 after rehydration.

[0130] 5. Packaging and warehousing, sampling inspection before leaving the factory, with a failure rate of ≤0.05%.

[0131] Advantages of this embodiment:

[0132] First, this method significantly improves production efficiency and packaging qualification rate by intentionally reducing the initial moisture content of nicotine products (i.e., the first nicotine product) during the production and packaging stage. In traditional processes, high-moisture materials are prone to adhesion and clumping during bag making and filling, leading to increased equipment downtime and higher defect rates. This method controls the moisture content to within 5-25 percentage points below the factory target by adjusting the binder concentration and extending the drying time during the granulation stage. This enhances material flowability, increases bag making speed (e.g., from 30 pieces / minute to 50 pieces / minute), and significantly reduces the packaging defect rate (≤0.1%). This improvement directly increases the output per unit time and reduces the frequency of equipment cleaning and maintenance costs caused by material adhesion.

[0133] Secondly, by introducing a humidification pack with directional slow-release function, a controllable microenvironment is created within the sealed container, enabling the slow and uniform transfer of moisture from the humidification pack to the nicotine product. The humidification pack employs an asymmetric laminated structure, with one side being a high-barrier material (such as an aluminum foil composite film) and the other side being a moisture-permeable but liquid-impermeable membrane (WVTR between 1000–3000 g·m⁻²·d⁻¹), effectively preventing moisture loss through the container wall while ensuring that moisture is released only towards the product. This design allows the product to rehydrate to the target moisture content (second nicotine product) within a preset time of 1–7 days, maintaining a stable water activity (aw) between 0.8 and 0.95, with fluctuations not exceeding ±0.03 (25℃). This process is highly controllable, avoiding problems such as uneven product moisture content, surface clumping, or localized mold growth caused by temperature and humidity fluctuations in traditional processes.

[0134] This method significantly improves the product's shelf-life stability and adaptability across climate zones. After rehydration, the humidification pack reaches dynamic equilibrium with the finished product (average effective humidity (aw) equal), and maintains stable water activity within the can during its shelf life (e.g., 18 months) through bidirectional humidification (moisture release or moisture absorption). For example, when increased external humidity causes a slight increase in the can's aw, the humidification pack absorbs excess moisture; conversely, it releases moisture, keeping the aw within the target range. This mechanism greatly reduces quality fluctuations caused by temperature and humidity changes during storage or transportation, ensuring high consistency in taste, nicotine release rate, and microbial safety (total bacterial count ≤100 CFU / g) experienced by consumers across different batches and regions. Furthermore, this finishing method offers high parameter customizability. The aw value, water vapor transmission rate (WVTR), and loading of the humidification pack can be flexibly adjusted according to different brands, flavors, or strength requirements. For example, high-strength nicotine pouches may require a higher aw to ensure efficient nicotine release, while fruit-flavored versions can highlight a fresher flavor by lowering the aw. This flexibility allows manufacturers to quickly adjust their production processes to meet diverse market demands without changing core formulas or equipment, thereby reducing new product development cycles and costs.

[0135] Finally, this method demonstrates good economic and environmental benefits while ensuring quality. By reducing the initial moisture content, energy consumption in the drying process is reduced; the miniaturization and directional design of the humidification pack avoids large-scale investment in traditional humidification equipment; and the reusability of sealed containers (such as food-grade PP cans) further reduces packaging costs. Overall, the post-processing method provided in Example 1 not only achieves precise control of "constant moisture content and moisture recovery" technically, but also demonstrates multiple advantages in industrial applications, including improved efficiency, guaranteed quality, and reduced costs.

[0136] The following demonstration will be based on specific experiments:

[0137] Experimental example:

[0138] The quantitative relationship (25°C) between oral flue gas water activity (Aw) and water content (MC) is approximately linear, with a target MC ≈ 30–40% corresponding to Aw ≈ 0.80–0.90. See Table 2 below:

[0139] The fitting result based on the test results is: MC = 1.561 × Aw − 1.007 (R ≈ 0.998). Therefore, MC = 40% corresponds to Aw ≈ 0.90; MC = 35% corresponds to Aw ≈ 0.85.

[0140] Table 2:

[0141]

[0142] The specific experimental procedure is as follows:

[0143] The portion of the cigarette containing the sample was dehydrated so that its initial moisture content was around 15-20%, its water activity was between 0.55 and 0.65, and the initial net weight of the entire pack of cigarettes containing the sample was around 8.5 + / - 0.8 grams.

[0144] A humidification tablet with a water activity of 0.95 (average net weight 4.5 g) was prepared and placed in the partially dehydrated dry cigarette box mentioned above as the experimental group; at the same time, a batch of blank control group (without humidification tablet) with the same partial dehydration was prepared; the cigarettes were stored at 25℃ and different relative humidities (RH 20% / 40% / 60% / 80%) for 30 days (720 h), and the changes in humidity inside the box, the changes in the weight of the whole box, and the weight and water activity of the cigarettes before and after 30 days were recorded and analyzed.

[0145] The initial conditions of the experimental group and the blank control group are shown in Table 3 below:

[0146] Table 3:

[0147]

[0148] The weight and water activity of the experimental group and the blank control group, and their changes, were recorded after 720 hours, as shown in Table 4 below:

[0149] Table 4:

[0150]

[0151] The changes in each group over time during the 720 hours recorded during the experiment are shown in Table 5 below:

[0152] Table 5:

[0153]

[0154] The analysis of the 720-hour experimental data from the experimental group and the blank control group yielded the following results:

[0155] 1. Key Insights and Analysis:

[0156] 1) Steady-state humidity and fluctuation: At 25℃ and RH=20 / 40 / 60 / 80%, the humidity fluctuation in the "with humidity control sheet" group is small (±1–2%RH); the RH in the "without humidity control sheet" group changes significantly with the environment, with the mean consistent with the environment and the standard deviation larger.

[0157] 2) 30-day moisturizing effect (with humidifier tablets vs. without humidifier tablets):

[0158] With humidity control tablets: within the RH range of 20-80%, the final Aw of the smoke in the mouth is generally 0.84-0.91 (meeting the standard), with an average increase of +0.24 to +0.27;

[0159] Without humidification tablets: There is no significant change at RH 20–60%. At RH 80%, the Aw of the cigarette in the mouth increases due to the permeability of the cigarette box.

[0160] The weight gain from water absorption of oral cigarettes increases with increasing ambient RH (RH20%≈+0.93g→RH80%≈+1.99g / box); the corresponding ΔAw is approximately in the range of +0.24~+0.27 (not strongly linearly dependent on RH, but more in line with "achieving the target bandwidth" rather than "the more the better").

[0161] 3) Mass transfer rate (overall mass trend): The experimental group with humidification tablets showed a daily average negative slope in the overall mass (typically -0.02~-0.025 g / day in a dry environment and -0.004 g / day in a humid environment), indicating that the drier the external environment, the faster the net water release rate; the blank group without humidification tablets mostly remained flat or slowly increased.

[0162] 2. Quantitative comparative analysis (25℃ / 30 days):

[0163] RH20%: With humidification tablets, ΔAw≈+0.267 (0.576→0.843), oral weight gain of smoke +0.93g; without tablets, ΔAw≈+0.017.

[0164] RH40%: With humidification tablets, ΔAw≈+0.256 (0.586→0.841), oral weight gain of smoke +1.18g; without tablets, ΔAw≈+0.016.

[0165] RH60%: With humidification tablets, ΔAw≈+0.238 (0.647→0.885), oral weight gain of smoke +1.32g; without tablets, ΔAw≈+0.025.

[0166] RH80%: With humidification tablets, ΔAw≈+0.257 (0.654→0.911), oral weight gain of smoke +1.99g; without tablets, ΔAw≈+0.134.

[0167] Conclusion: At 25℃, some tablets can quickly bring the oral tobacco to the target bandwidth of Aw≈0.85–0.90+; the more humid the outside environment, the more water the oral tobacco itself stores, and the higher the final Aw tends to be, but the overall increase still remains around ~0.25.

[0168] 3. Stability and Rate Analysis:

[0169] Steady-state bandwidth: The RH inside the test box with the humidity control plate was concentrated in a narrow fluctuation band of ±1–2%RH under various external RH levels;

[0170] Stabilization time: Typically, it takes 7-15 days to advance to Aw≥0.85;

[0171] Net water release rate (the rate at which moisture migrates from the humidifying sheet into the mouth-held tobacco):

[0172] RH20%: ~−0.025g / day (drier → faster water release);

[0173] RH40%: ~−0.021g / day;

[0174] RH 60%: ~−0.014g / day;

[0175] RH80%: ~−0.004g / day;

[0176] Environmental priority: The drier the environment during production / warehousing (RH20–40%), the faster the net water release; under RH80% environment, oral tobacco first fully absorbs water (higher tablet weight gain), and the Aw endpoint is more likely to approach or exceed 0.90.

[0177] Example 2

[0178] A manufacturing process for oral nicotine products, comprising the following steps:

[0179] First, design and determine the raw material formula. For example, the following formula can be used as a reference:

[0180] Tobacco materials: 10%~70% (usually powdered flue-cured tobacco, sun-cured tobacco, burley tobacco, etc., with a particle size of 50~100 mesh);

[0181] Moisture: 10%~60%;

[0182] pH adjusters: 0.01%~2% (such as sodium bicarbonate, sodium hydroxide, etc., used to adjust pH value and nicotine release);

[0183] Flavoring agents: 1%~20% (such as xylitol, maltitol, menthol, etc.);

[0184] Humectant: 1%~10% (such as glycerin, propylene glycol, etc.);

[0185] Fragrance: as needed (natural or synthetic fragrance);

[0186] Special additives: such as bitter tea extract (used to reduce oral health risks).

[0187] In other embodiments, there are more feasible formulations available for design use.

[0188] Step S01: Raw material pretreatment;

[0189] The tobacco material is crushed and sieved to obtain coarse tobacco powder of the required particle size.

[0190] Step S02: Mixing and blending;

[0191] Add water, flavoring agent (partially) and humectant to the tobacco powder and mix well.

[0192] Step S03: Fumigation treatment;

[0193] Steam fumigation (100-110℃ steam treatment for 20-40 minutes) is used to sterilize, ripen, and regulate moisture.

[0194] Step S04: Cooling and seasoning;

[0195] After fumigation, the material is cooled to room temperature, and then the remaining flavoring agents, pH adjusters, and fragrances are added and mixed evenly.

[0196] Step S05 (optional): Alcoholization;

[0197] Some processes involve aging the mixture at low temperatures (1-5°C) for 1-7 days to achieve a more harmonious and blended flavor.

[0198] Step S06: Adjust humidity;

[0199] The material humidity is adjusted to the humidity range of the first nicotine product to obtain the first nicotine product, which is lower than the factory standard humidity range.

[0200] Step S07: Pack the predetermined quantity of the first nicotine product into a pre-prepared sealed container;

[0201] Step S08: After placing the humidity regulating pack inside the sealed container, seal the sealed container;

[0202] Step S09: Store the sealed container at room temperature to allow the first nicotine product to rehydrate to the target water content within a preset time range to form the second nicotine product, and maintain the water activity in the sealed container within a preset water activity range.

[0203] Steps S07 to S09 are implemented in accordance with the steps described in Example 1.

[0204] Advantages of implementing this embodiment:

[0205] First, this process establishes a comprehensive production system encompassing raw material formulation design, pretreatment, mixing, fumigation, cooling and flavoring, aging, and finishing. The scientific design of the raw material formulation (e.g., tobacco materials comprising 10%–70%, supplemented with pH adjusters, flavoring agents, humectants, and functional additives) provides a rich variety of flavor options and expanded efficacy possibilities for the product. For example, the introduction of bitter tea extract can reduce oral mucosal irritation without affecting nicotine release, enhancing the product's consumer safety. This formulation flexibility allows companies to quickly respond to and iterate products to meet different market demands (such as regional taste preferences and harm reduction claims).

[0206] Secondly, the parameter settings of each step in the process are closely linked, especially the coordination between the finishing method and the preceding production. In step S06, the material is humidified to a state below the factory standard for first-stage nicotine products, providing operational space for subsequent rehydration. Steps S07-S09 directly introduce the directional slow-release mechanism of the humidity-regulating pack from Example 1, achieving closed-loop control of "dry packaging – sealed rehydration – dynamic balance". This responsive process design avoids problems such as clumping and uneven flavoring after fumigation due to excessive moisture content in traditional production, while ensuring that the final product's moisture content and aw value accurately meet the standards.

[0207] Third, this process incorporates quality control points at multiple stages to comprehensively improve product consistency. For example, raw material crushing and sieving (50-100 mesh) ensures uniform particle size; fumigation (100-110℃ steam, 20-40 minutes) combines sterilization, maturation, and moisture regulation, reducing the pressure on subsequent microbial control; low-temperature aging (1-5℃, 1-7 days) promotes the fusion and stability of flavor compounds; and the use of humidification packets further controls overall moisture content fluctuations to ≤±1%, with aw fluctuations ≤±0.03%. This multi-stage quality control mode significantly reduces intra-batch and inter-batch variations, meeting the high requirements for product consistency in large-scale industrial production. Furthermore, the process has good scalability and adaptability. It is not only suitable for the production of common nicotine pouches (powder / granule type), but can also be adapted to different dosage forms such as film and soft-pack by adjusting parameters. For example, if producing film-type mouth-held smoke, the type and concentration of the binder can be adjusted in step S02; if producing high-moisture mouth-held smoke, a lower initial moisture content can be preset in step S06, and the rewetting rate can be increased by adjusting the moisture content of the packaging. This "modular" process design makes multifunctional production lines possible, improving equipment utilization and production flexibility.

[0208] Finally, this process demonstrates outstanding economic benefits and sustainability. The low-moisture production in the initial stage reduces drying energy consumption and material loss; the post-processing stage utilizes ambient temperature rehumidification, avoiding the need for additional heating or humidification equipment; the miniaturization and directional design of the humidification packs lowers packaging costs; and the excellent barrier properties of sealed containers (such as aluminum foil bags and PP cans) extend product shelf life and reduce returns due to spoilage. Overall, Example 2 not only improves product quality and stability through process optimization but also reduces overall production costs through process integration, giving the company a significant competitive advantage in the market.

[0209] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology 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 determined by the scope of the claims.

Claims

1. A finishing method applied to the manufacturing process of oral nicotine products, characterized in that, The post-processing method includes the following steps: Obtain a newly produced first nicotine product, the moisture content of which is lower than the target moisture content at the factory; The predetermined quantity of the first nicotine product is packed into a pre-prepared sealed container; After placing a humidity-regulating pack inside the sealed container, the container is sealed. The humidity-regulating pack includes a humidity-regulating composition and a covering structure. The covering structure includes at least one moisture-permeable but liquid-impermeable membrane. The moisture-permeable but liquid-impermeable membrane satisfies a water vapor transmission rate of 1000-3000 g·m³ at 25°C and 85% relative humidity. -2 ·d -1 The loading amount of the humidity-regulating composition in the humidity-regulating package and the water vapor transmission rate of the moisture-permeable but liquid-impermeable functional membrane are selected such that the time to reach half of the rewetting progress is 48-96 hours and the steady-state fluctuation of water activity is ≤±0.

03. The sealed container is stored at room temperature, allowing the first nicotine product to rehydrate to the target water content within a preset time range to form the second nicotine product, while maintaining the water activity in the sealed container within a preset water activity range.

2. The finishing method for oral nicotine products according to claim 1, characterized in that, The preset water activity is 0.8~0.95, and the fluctuation at 25℃ does not exceed ±0.

03.

3. The finishing method for oral nicotine products according to claim 1, characterized in that, The ambient temperature is 15~35℃.

4. The finishing method for oral nicotine product manufacturing process according to claim 1, characterized in that, The preset time range is 1 to 7 days.

5. The finishing method for oral nicotine products according to claim 1, characterized in that, The first nicotine product has a water content that is 5 to 25 percent lower by mass than the second nicotine product.

6. The finishing method for oral nicotine product manufacturing process according to claim 2, characterized in that, The water activity of the humidification pack is determined based on the target water content at the factory.

7. The finishing method for use in the production process of oral nicotine products according to any one of claims 1 to 6, characterized in that, The coating structure is a directional slow-release structure that is barrier on one side and permeable to moisture on the other, including a barrier surface and a permeable surface. The barrier surface is a low-permeability, high-barrier material fixedly attached to the inner surface of the sealed container, and the permeable surface is a permeable but liquid-impermeable functional membrane.

8. A manufacturing process for a sublingual nicotine product, characterized in that, The manufacturing process for oral nicotine products includes the post-processing method described in any one of claims 1 to 7 for use in the manufacturing process of oral nicotine products.

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