Combustion-free cigarette

Abstract

A combustion-free cigarette consisting of a sleeve (1), to the inner casing (1a) of which a nicotine solution is applied, in which it is proposed according to the invention that the sleeve (1) is closed at one of its two ends by a partially air-tight draw-in brake (2) and the nicotine solution consists of a quantity of 0.8-1.2 mg of nicotine dissolved in 75-105 μl of ethanol, the nicotine solution being applied as an at least partial wetting of the inner casing (1a). The cigarette according to the invention reproduces the properties of a conventional cigarette in its dispensing of nicotine by the nicotine being absorbed in a sufficient quantity from the air flow arising within the sleeve (1) during the customary draw-in process and being available for inhaling.

Description

[0001] The invention relates to a non-combustible cigarette consisting of a sleeve on the inner surface of which a nicotine solution is applied, according to the preamble of claim 1.

[0002] Conventional cigarettes rely on the combustion of nicotine-containing tobacco enclosed in a paper tube. The combustion process releases nicotine, which the smoker inhales by drawing in so-called mainstream smoke. Between puffs, the combustion process continues, with nicotine escaping into the environment in so-called sidestream smoke without being inhaled by the smoker. The desired effect for the smoker is due to the inhaled nicotine, which has an activating effect on cells of the autonomic nervous system. Conventional cigarettes contain approximately 10 mg of nicotine, but due to combustion and sidestream smoke, only about 1-2 mg of nicotine is inhaled by the smoker when smoking the entire cigarette. This demonstrates that with conventional cigarettes, the majority of the nicotine in the tobacco is not inhaled but rather burns or escapes.Instead, a multitude of other tobacco components and combustion products are inhaled, which have proven carcinogenic effects, particularly tar substances, benzene, lead, and cadmium. Nicotine itself, however, is not carcinogenic. While nicotine is considered an addictive substance and can cause dependence, the addictive effect is demonstrably greatly increased by substances contained in tobacco smoke, such as the monoamine oxidase inhibitors (MAOIs) found in tobacco smoke. If the combustion process of tobacco could be eliminated, the addictive potential of nicotine would also be significantly reduced.

[0003] Therefore, attempts were made to provide combustion-free cigarettes in which nicotine is applied to carrier bodies of different designs and made available for inhalation without other ingredients of natural tobacco.

[0004] US patent 4,800,903 describes a porous support body made of polyethylene, polypropylene, or similar plastics. Alternatively, support bodies made of a solid (non-porous) material were also described.

[0005] US patent 4,284,089 describes a porous carrier body that is cylindrical in shape and funnel-shaped at both ends. The two funnel-shaped sections are connected by a channel through which the nicotine mixture can flow. The carrier body, with funnels at both ends, is located inside a sleeve.

[0006] US Patent 4,813,437 discloses a cigarette-shaped nicotine delivery device incorporating multiple sections and several types of cylindrical porous carriers. These carriers are made of plastic and cellulose fibers. Manufacturing with multiple zones and multiple porous carriers requires several production steps, resulting in high manufacturing costs.

[0007] US Patent 6,089,632 describes a cylindrical, porous carrier body designed as a nicotine reservoir. This porous carrier body is soaked in a mixing vessel with a nicotine solution, then dried, thus loading it with nicotine, and inserted into a tube. For use, the tube containing the carrier body must be inserted into a pipe-shaped inhalation device.

[0008] WO2006002445 A2 discloses a non-combustible cigarette which contains in a casing a carrier body onto which nicotine and ethanol are applied.

[0009] EP0144934 A2 teaches the impregnation of paper for wrapping cigarettes with a solution containing nicotine and ethanol. The impregnated paper is then dried.

[0010] However, it has been shown that open-pored carriers have pores of varying sizes, resulting in an undefined pore surface area. This is disadvantageous when impregnating the porous carriers with a nicotine solution, as varying amounts of nicotine are always deposited within a single open-pored carrier. For a non-combustible cigarette, however, the deposited nicotine amount must be precisely adjustable, otherwise the consumer could ingest excessive amounts of nicotine, exceeding the amount stated on the packaging.

[0011] The aforementioned solutions have also failed to gain market acceptance because their nicotine delivery does not satisfactorily replicate the characteristics of a conventional cigarette. For market acceptance, it is not enough to simply store the required amount of nicotine solution in a tube; the nicotine must also be absorbed in sufficient quantity by the airflow generated within the tube during the typical inhalation process and be readily available for inhalation. Experimental studies of typical smoking behavior show that when consuming a conventional cigarette, at least 10-20 puffs are typically taken, with each puff having a volume of approximately 40-80 ml. The typical interval between puffs is 10-40 seconds. The total consumption time is approximately 10-15 minutes.With typical smoking behavior, nicotine must be released in the usual amount, approximately 1 mg, via a non-combustion cigarette and made available for inhalation. Under standard conditions, however, nicotine exists as an oily liquid that is low to very low volatile (boiling point 246°C, vapor pressure 0.058 hPa at 20°C, 0.13 hPa at 30°C, and 0.58 hPa at 50°C). Conventional non-combustion cigarettes are unable to transfer the nicotine quickly enough from its attachment to solid surfaces of the cigarette body and other materials into the inhaled air. If, under typical smoking behavior, the nicotine cannot be released in the usual amount via a non-combustion cigarette and made available for inhalation, the desired effect is lacking, and the acceptance of such a product suffers despite its health benefits due to the absence of carcinogenic substances.

[0012] The object of the invention is therefore to provide a combustion-free cigarette in which the nicotine can be brought sufficiently quickly from its deposition on solid surfaces into the intake stream, so that the effect intended by the smoker of nicotine absorption from conventional cigarettes by inhalation can be reproduced in a suitable manner.

[0013] This objective is achieved by the features of claim 1. Claim 1 relates to a combustionless cigarette consisting of a tube on the inner surface of which a nicotine solution is applied, wherein, according to the invention, the tube is proposed to be sealed at one of its two ends with a partially airtight intake barrier, and the nicotine solution consists of an amount of 0.8-1.2 mg of nicotine dissolved in 75-105 µl of ethanol, wherein the nicotine solution is applied as an at least partial coating of the inner surface. The cigarette according to the invention corresponds in its dimensions to conventional cigarettes, as will be explained in more detail below, and also imitates the construction of a conventional cigarette with the intake barrier arranged at one end.Unlike the filter of conventional cigarettes, the intake restrictor does not filter the inhaled airflow, but rather creates flow resistance within the otherwise empty tube, mimicking the intake resistance of a conventional cigarette, and prevents axial airflow during storage. Of course, the intake restrictor can also be formed from a conventional cigarette filter, which does not filter nicotine itself.

[0014] According to the invention, the nicotine is applied to the inner sleeve of the cigarette tube as a nicotine solution of 0.8-1.2 mg dissolved in 75-105 µl of ethanol, preferably as a nicotine solution of 1 mg dissolved in 100 µl of ethanol. Nicotine is readily soluble in ethanol. However, the evaporation behavior of the nicotine solution in ethanol, which in turn depends on the relative concentration, is crucial for the applicability of such a solution for non-combustible cigarettes. As will be explained in more detail below, the applicants have demonstrated that, when periodic airflows are applied by inhalation, as corresponds to typical smoking behavior, a solution according to the invention ensures the release of nicotine from its adhesion to the inner sleeve into the airflow in accumulated quantities of 250-800 µg within the timeframe of 10-20 minutes, corresponding to typical smoking behavior.The ethanol enables co-evaporation of nicotine with ethanol, as the ethanol mobilizes the otherwise difficult-to-evaporate nicotine into the gas phase.

[0015] Crucial to this is also the surface finish of the inner lining, which, according to the invention, must ensure at least partial wetting of the inner lining by the nicotine solution. The wettability of a surface by a liquid is characterized by the contact angle (also referred to as the "wetting angle"), which denotes the angle formed by a liquid droplet on the surface of the solid. The shape that the liquid droplet assumes on a surface depends on the surface tension of the liquid and the surface finish. At the boundary between the liquid droplet and the gaseous environment, the surface tension causes a curved contour. At the edge of the liquid droplet, where the contour transitions into the solid surface, the contact angle is formed between the liquid / solid interface and the tangent to the liquid / gas interface.If the liquid flows evenly across the solid surface, complete wetting occurs with a contact angle of 0°. If the contact angle is between 0° and 90°, the surface is partially wettable. An angle between 90° and 180° means that the surface is not wettable. The inner sleeve of the cigarette according to the invention must be partially wettable, i.e., have a contact angle with the wetting liquid of less than 90°. Preferably, the nicotine solution is applied as at least partial wetting of the inner sleeve with a contact angle of no more than 75°.

[0016] One possibility for this is to manufacture the sleeve from bagasse. Bagasse refers to fibrous residues that are primarily generated during sugarcane processing and have recently found use as a substitute for plastics in the food industry because they can be processed into grease- and water-resistant packaging. According to the invention, sleeves can be manufactured by mixing bagasse with water to form a slurry, which is then shaped into sleeves and dried. After drying, the outer layer of the sleeves is coated with melamine resins or biodegradable PLA (polylactic acid) to create water resistance. The inner layer of the sleeves exhibits the wettability required by the invention. Furthermore, the sleeves manufactured in this way are biodegradable and can therefore be easily disposed of.

[0017] Another option is to manufacture the sleeve from glass, with the inner surface roughened to ensure a maximum contact angle of 90°. Glass can be reused for the same application, for example by being collected, cleaned, and sterilized via a deposit system, or it can be reused for a different application, for example by being placed in glass recycling containers.

[0018] Another cost-effective manufacturing option for the sleeve is to produce it from a plastic that can be applied using FFF (Fused Filament Fabrication). FFF (also known as Fused Deposition Modeling) is an additive manufacturing process ("3D printing") in which a molten plastic is applied layer by layer to a build platform. PLA and ABS (acrylonitrile butadiene styrene copolymer), as well as PETG, are primarily used as plastics for this purpose. PETG is a glycol-modified polyethylene terephthalate (PET) characterized by its particularly high transparency and low viscosity. These plastics are fed into a heated nozzle as a plastic filament and melted. The molten plastic material is then automatically applied layer by layer according to the sleeve geometry and cured to produce a sleeve according to the invention.The polymer sleeves produced in this way exhibit the wettability required according to the invention on the inner sheath.

[0019] Regarding the tube geometry, it is proposed that the inner sleeve, at least partially wetted by the nicotine solution, has a surface area of ​​500–2000 mm², preferably 1000 mm². The amount of 75–105 µl of ethanol proposed according to the invention is applied to this surface, as will be explained in more detail below. Regarding the tube dimensions, it is proposed that the tube be cylindrical with a length of 50–100 mm and an inner diameter of 3–6 mm. The wall thickness of the tube is 1.5 mm to 2.5 mm, preferably 1.5 mm, to ensure sufficient strength to prevent the chemicals from diffusing through the wall.

[0020] Furthermore, it is proposed that flavorings be added to the nicotine solution. Nicotine, in the quantities used here, is an almost tasteless and odorless substance. The flavorings serve to make the inhaled nicotine solution perceptible to the senses, both to enhance the enjoyment of consumption and to indicate to the consumer that the nicotine solution in one cigarette has been completely consumed. Unlike conventional cigarettes, which burn up quickly, the cigarette according to the invention remains physically intact apart from the consumption of the applied nicotine solution. Moreover, the cigarette according to the invention is suitable for nicotine delivery over a longer period than a conventional cigarette, as will be explained in more detail below, namely for approximately 100 puffs, which, assuming a 10-second pause between puffs, corresponds to a total consumption time of approximately 15 minutes.During these approximately 100 puffs, the entire amount of nicotine solution applied to the inner coating, and thus also the flavorings, evaporates. Crucially, the presence of the flavorings does not adversely affect the co-evaporation of nicotine with ethanol, a fact demonstrated by the applicants for a number of flavorings, as will be explained in more detail below.

[0021] Furthermore, it is proposed that the nicotine used in the nicotine solution has a pH value in the alkaline range. The pH value of cigarette smoke from conventional cigarette tobacco is in the range of 6.3–5.6, i.e., in the acidic range. The nicotine in the nicotine solution preferably proposed within the scope of the invention, with a pH value in the alkaline range, is more similar to cigar or pipe tobacco obtained from leaves harvested in their unripe state. The pH value of cigar smoke from conventional cigar tobacco is in the range of 8.0–8.6, i.e., in the alkaline range. Free nicotine from such alkaline smoke is readily absorbed through mucous membranes. By using nicotine with a pH value in the alkaline range, this effect is utilized, and the effect of cigar or pipe tobacco is mimicked.

[0022] The invention will be explained in more detail below with reference to exemplary embodiments and the accompanying figures. These figures show... Fig. 1 a schematic view of an embodiment of a cigarette according to the invention, Fig. 2 experimental results on the cumulative amount of nicotine in µg absorbed by an airflow within a tube over the number of simulated puffs, wherein the tube is made of PETG that can be applied using FFF (Fused Filament Fabrication) manufacturing processes, Fig. 3 experimental results on the cumulative effect of an airflow within a sleeve according to Fig. 2 Amount of ethanol consumed (uncalibrated) over the number of simulated puffs, and the Fig. 4Experimental results on the cumulative amount of nicotine in µg absorbed by an airflow within a tube over the number of simulated puffs, wherein the tube is made of glass, the inner surface of which is roughened to ensure a contact angle of a maximum of 90°.

[0023] First, attention will be drawn to the Fig. 1Reference is made to Figure 1, which shows a schematic view of an embodiment of a cigarette according to the invention. The cigarette according to the invention is similar in its dimensions to a conventional tobacco cigarette and has a cylindrical sleeve 1 with a length of 50-100 mm and an inner diameter of 3-6 mm. The inner lining 1a of the sleeve 1 has a surface area of ​​500-2000 mm², preferably 1000 mm². The outer lining 1b of the sleeve 1 can be colored with food-safe dye to give the sleeve 1, for example, a white color. The wall thickness of the sleeve 1 is 1.5 mm to 2.5 mm, preferably 1.5 mm, to ensure sufficient strength to prevent the chemicals from diffusing through the wall.

[0024] At its first end, the sleeve 1 is closed with a partially airtight intake restrictor 2, which is designed, for example, as a conventional cigarette filter. The intake restrictor 2 provides an intake resistance that reduces the airflow velocity within the sleeve 1, thus increasing the contact time between the airflow and the inner sleeve 1a. This also provides the smoker with the familiar intake resistance. The drawn-in air enters the interior of the sleeve 1 through the opening at the opposite, second end, travels axially through the interior of the sleeve 1 towards the intake restrictor 2, and passes through the intake restrictor 2 until it exits the cigarette according to the invention at the free end of the intake restrictor.Alternatively, the intake brake 2 can also be designed as a fixed, cylindrical intake plug with a conical channel made of biodegradable plastic, which has a conical air channel inside that tapers towards the intake opening and is open at both ends.

[0025] The open, second end of the cigarette according to the invention can be sealed with a foil seal to prevent the nicotine solution from escaping during storage. Such a foil seal would have to be removed before use. However, the applicants have determined that sealing the second, open end of the cigarette is unnecessary because the escape of evaporated nicotine solution is negligible under the given geometric conditions, particularly when cigarettes according to the invention are stored in an airtight package. Evidently, the air exchange between the one-sided sealed tube 1 and the surroundings is sufficiently low that saturation of the evaporated nicotine solution quickly occurs within the tube 1, preventing further evaporation.

[0026] A quantity of 75-105 µl of ethanol, mixed with 0.8-1.2 mg of nicotine, is applied to the surface of the inner jacket 1a. The nicotine solution can be applied to the inner jacket 1a using a dosing and spray needle that has numerous holes or nozzles along its axial length. With such a dosing and spray needle, it is possible to wet the entire inner jacket 1a of the sleeve 1 with the nicotine solution in a single spray.

[0027] The following studies demonstrated that sufficient mobilization and transport of the applied nicotine by a periodic airflow, as corresponds to typical smoking behavior. Experimental proof:

[0028] First, the co-evaporation of nicotine and ethanol was demonstrated and quantified using a nicotine solution of 1 mg nicotine in 100 µl ethanol. The evaporation was intended to occur in a process resembling typical smoking behavior. To this end, a male smoker was asked to inhale from a tube connected to a graduated cylinder, mimicking the way he would inhale from a cigarette. This experiment was repeated with a female smoker. Both individuals repeated the process at least five times. The results showed that typical inhalations by these individuals had volumes of approximately 40–80 m³. Interviews with the participants revealed that they typically take puffs of approximately 10–40 seconds between puffs on a standard cigarette.

[0029] To reproducibly replicate this smoking behavior for laboratory investigations, a measurement setup was developed in which air was cyclically drawn through a tube whose dimensions corresponded to a cigarette according to the invention and whose inner lining 1a was coated with a 100 µl ethanol-nicotine mixture containing 1 mg / 100 µl nicotine. Exhalation did not occur through the tube. These tubes filled with a nicotine-ethanol mixture are subsequently referred to as evaporator tubes. In a first experiment, the evaporator tubes were manufactured from PETG using a fused filament fabrication (FFF) process. These evaporator tubes were produced using a commercially available Ultimaker 2+ 3D printer with a 0.25 mm printhead. The thickness of the applied plastic layers was between 60-150µm.

[0030] The measurement setup also allowed for a variable time interval between draws to be programmed using a microcontroller controlling the setup. Suction was performed using two 50ml syringes connected in parallel, driven by a linear motor. A switching valve allowed air to be drawn from the evaporator tube through an adsorbent tube (Tenax tube), an alcohol sensor, and a UV sensor. The switching valve then shut off the airflow through the tubes, allowing the syringes to be emptied into the ambient air.

[0031] The adsorbent tubes were filled with Tenax. Tenax is the brand name of poly(2,6-diphenyl-p-phenylene oxide), a polymeric adsorbent resin used as column packing material for gas chromatography. Substances like nicotine adsorb almost completely to the resin when the amount of substance is significantly below the binding capacity. Heating allows the substances to be desorbed and thus transferred in the gas phase to a mass spectrometer for further analysis. The Tenax tubes (17.8 cm) were analyzed using a Gerstel TDS 3 with a TDS A2 autosampler, typically with a 20:1 or 5:1 split. The molecules to be analyzed are transferred into the gas phase (desorption) and ionized by heating in an inert gas atmosphere under reduced pressure. The ions are then accelerated by an electric field and fed to an analyzer, which separates them according to their mass-to-charge ratio m / z.The molecules can be fragmented in the process, which can lead to different peaks in the spectrogram.

[0032] The resulting chromatograms showed clear nicotine peaks, which were quantified by the nicotine-typical m / z ratio at 133 and 162. No influence from methanol or traces of other organic compounds was found in the corresponding m / z ranges. A total of 30 intake tests were performed, and the intake air from trains 1-3, 3-5, 5-10, 10-20, and 20-30 was collected and analyzed chromatographically.

[0033] Since a measure of the amount of substance is the integral area under the curve of a peak, the peaks were integrated for further analysis, and the areas were thus determined. For calibration, glass tubes were filled with known amounts of nicotine and these were also measured using thermal desorpation. From the ratios of the peak areas from the calibration measurements to the areas from the actual experiments, the real, actual amount of substance could be estimated.

[0034] The experiments showed that approximately 20 µg of nicotine were released after 30 puffs. The curve of cumulative nicotine release over time shows that it continues to rise even after 30 puffs. Therefore, further experiments were conducted with a larger number of puffs. Additionally, the amount of alcohol that evaporated was quantified using the integrated alcohol sensor, although no absolute measurement was taken. Since a known quantity of 100 µl was used, precise quantification is unnecessary. Fig. 2 The measured course of the cumulative nicotine intake is shown, and in the Fig. 3 the measured trend of the cumulative amount of alcohol, where the amount of alcohol was only given in arbitrary units ("au"), since, as mentioned, no exact calibration was carried out.

[0035] In the described measurements, a pause time of 10 seconds was programmed between each move, resulting in 60 moves being carried out in 10 minutes.

[0036] Again Fig. 2 As can be seen, nicotine was delivered over 150 puffs, with the delivery appearing to follow a biphasic (sigmoid) curve. As the Fig. 3 The alcohol, which could be extracted, was also released sigmoidally, but significantly faster. Apparently, nicotine release is concentration-dependent. The total amount of nicotine released over time is approximately 75% of the amount administered.

[0037] As mentioned, these measurements were performed using 3D-printed polymer tubes as evaporation tubes, which had a relatively porous wall structure. Since it can be assumed that the porous wall structure slowed evaporation due to capillary effects and the resulting reduced exposed surface area, the tests were repeated using roughened glass tubes. For this purpose, commercially available Pasteur pipettes were cut to length using a glass cutter and then roughened with a grinding attachment for a Dremel tool. This roughness reduced the contact angle to below 90° and thus caused the nicotine-ethanol mixture to spread within the glass tube. As a result, after only 80 puffs, or approximately 14 minutes, the ethanol and nicotine were completely released, as described in the [reference to the previous text]. Fig. 4 as is evident.

[0038] The results presented here are consistent with previous studies by the applicants, in which residual amounts of nicotine were determined in tubes containing an evaporated alcohol-nicotine solution. These studies showed that only very small residual amounts were detectable.

[0039] Finally, the influence of flavorings on the co-evaporation of nicotine with ethanol was investigated. For this purpose, the following flavorings were added to the nicotine-ethanol mixture in various test series: "Smoke Flavor" (product no.: 01400238), "Chocolate Flavor" (product no.: 01602888), "Tea Flavor" (product no.: 628 / 19A), "Coffee Flavor" (product no.: 01602932), and "Akrastevia XI" (product no.: 86600108). 10 µl of each of these solutions were taken, and this mixture was diluted with ethanol until only a faint (tolerable) sensory impression could be subjectively detected. 100 µl of this mixture was placed in an evaporator tube along with 100 µl of the nicotine-ethanol solution, taking care to ensure that the solutions did not mix. Then, 150 puffs were taken with the apparatus, and the adsorbent tubes were subsequently eluted with methanol. As a control, the experiment was also performed without flavorings.The methanol eluates were then applied to an Alox-RP18 thin-layer chromatography plate (Alugram-RP18). After drying, a capillary-driven run was performed using methanol as the mobile phase. The nicotine bands visible under UV illumination did not differ noticeably between the samples with and without flavorings. This procedure was chosen because the flavorings were not precisely specified and quantified, and contamination of the thermal desorption system was to be avoided.

[0040] Nicotine-ethanol evaporation measurements were repeated at least three times using the 3D-printed evaporation tubes and showed consistent results. Measurements with reduced evaporation time due to roughened glass surfaces and those with flavorings were each performed twice and also showed consistent results.

[0041] These experimental investigations show that intermittent, pulsed ventilation of a tube containing a 1 mg / 100 µl nicotine-ethanol solution can transfer significant amounts of nicotine into the gas phase and carry it away. Using a 3D-printed porous plastic tube as a carrier, approximately 750 µg of nicotine (1 mg applied) was released over 30 minutes. This co-evaporation of ethanol and nicotine was not noticeably affected by flavorings. The rate of evaporation can be influenced to a certain extent by appropriately selecting the surface of the evaporation tube. In this particular case, using a roughened glass tube, nicotine was released over a period of about 15 minutes with an inhalation frequency of one puff every 10 seconds, with approximately 70% of the originally applied nicotine being detected in the gas phase.

[0042] The applicants were thus able to demonstrate that, when periodic airflows are applied by inhaling, as corresponds to typical smoking behavior, a solution according to the invention ensures the release of nicotine from its adhesion to the inner sleeve 1a into the airflow in accumulated quantities of 250-800 µg within the timeframe of 10-20 minutes, corresponding to typical smoking behavior. The cigarette according to the invention thus reproduces the properties of a conventional cigarette in its nicotine delivery, in that the nicotine is absorbed in sufficient quantity by the airflow generated within the sleeve 1 during the usual inhalation process and is available for inhalation. The ethanol enables co-evaporation of nicotine with ethanol, as the ethanol mobilizes the otherwise poorly evaporating nicotine into the gas phase.The cigarette according to the invention can also be consumed without restriction, i.e., in cafes, bars or restaurants, but also in train stations or airplanes, and is compliant with non-smoking laws, since neither harmful tobacco combustion smoke nor any form of smoldering as with tobacco heaters or vapor as with e-cigarettes or e-shishas is emitted.

Claims

1. Combustion-free cigarette consisting of a sleeve (1), to the inner casing (1a) of which a nicotine solution is applied, characterized in that the sleeve (1) is closed at one of its two ends by a partially air-tight draw-in brake (2) and the nicotine solution consists of an amount of 0.8-1.2 mg of nicotine dissolved in 75-105 µl of ethanol, the nicotine solution being applied as an at least partial wetting of the inner casing (1a).

2. Combustion-free cigarette according to claim 1, characterized in that the nicotine solution consists of an amount of 1 mg nicotine dissolved in 100 µl ethanol.

3. Combustion-free cigarette according to claim 1 or 2, characterized in that the nicotine solution is applied as an at least partial wetting of the inner casing (1a) with a maximum contact angle of 75°.

4. Combustion-free cigarette according to one of claims 1 to 3, characterized in that the sleeve (1) is made of bagasse.

5. Combustion-free cigarette according to one claim 1 or 2, characterized in that the sleeve (1) is made of glass, the inner casing (1a) being roughened to ensure a contact angle of a maximum of 90°.

6. Combustion-free cigarette according to one of claims 1 to 3, characterized in that the sleeve (1) is made of a plastic that can be applied using an FFF (Fused Filament Fabrication) manufacturing process.

7. Combustion-free cigarette according to one of claims 1 to 6, characterized in that the inner casing (1a) that is at least partially wetted by the nicotine solution has a surface area of 500-2000 mm2.

8. Combustion-free cigarette according to claim 7, characterized in that the inner casing (1a) which is at least partially wetted by the nicotine solution has a surface area of 1000 mm2.

9. Combustion-free cigarette according to one of claims 1 to 8, characterized in that the sleeve (1) is cylindrical and has a length of 50-100mm and an inner diameter of 3-6mm.

10. Combustion-free cigarette according to one of claims 1 to 9, characterized in that flavorings are added to the nicotine solution.

11. Combustion-free cigarette according to one of claims 1 to 10, characterized in that the nicotine used for the nicotine solution has a pH value in the basic range.

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