EP4250980A1

EP4250980A1 - Wick

Info

Publication number: EP4250980A1
Application number: EP21835165.8A
Authority: EP
Inventors: Corrado Tasselli
Original assignee: McNeil AB
Current assignee: McNeil AB
Priority date: 2020-11-30
Filing date: 2021-11-29
Publication date: 2023-10-04
Also published as: WO2022112570A1; US20240008536A1

Abstract

A wick is provided that is suitable for an electronic nicotine delivery system. The wick is permeable and is formed from a sintered metal powder.

Description

WICK

The present invention relates to a wick. The wick is suitable for an electronic nicotine delivery system. The present invention also relates to a method of forming the wick. Further, the present invention relates to an electronic nicotine delivery system containing the wick.

Electronic Nicotine Delivery Systems, ENDS, can be used as a replacement for traditional tobacco products, such as cigarettes. They may also be used in order to decrease an individual’s reliance on nicotine as part of a smoking cessation programme.

Electronic nicotine delivery systems commonly comprise a reservoir of nicotine-containing solution and a heater that can heat the solution to form an aerosol which can be delivered to the user. A wick is commonly used to convey the nicotine-containing solution from the reservoir to the heater.

The requirements for the wick can vary depending on the configuration of the device. For example, the wick is commonly part of a replaceable component of the electronic nicotine delivery system and thus its longevity is not a major consideration. However, enhancing the properties of the wick would increase the design flexibility of electronic nicotine delivery systems.

The present invention provides a wick for an electronic nicotine delivery system, wherein the wick is formed from a sintered metal powder, and wherein the wick is permeable.

Such a wick has been found to be particularly durable and provide consistent performance within an electronic nicotine delivery system. This durability and consistent performance can also ensure that the nicotine-containing solution is extracted from the reservoir in a controlled manner, avoiding any undesired leakage of the nicotine-containing solution via the wick.

A wick utilises capillary action to convey fluid within itself. In this manner, the wick can transport fluid from one place within the electronic nicotine delivery system, such as a reservoir, to another place, such as a heater. As fluid is removed from the wick, such as by being vaporised by the heat provided by the heater, further fluid can be drawn up from the fluid source. Therefore, the wick performs an important role conveying fluid to ensure a consistent delivery of nicotine to the user.

As noted above, the wick is formed from a sintered metal powder. In other words, the wick is formed by sintering a metal powder into the final form of the wick. Sintering is a well- known process of increasing the density of a powder by heating the powder to a temperature below its melting point. During the sintering of the powder, its density is increased with a corresponding reduction in porosity. It is known that the desired final properties of the sintered body can be achieved by using appropriate processing conditions. These can be determined experimentally by adjusting various parameters such as the powder particle size, initial compaction of the powder, and temperature profile used during sintering. Such adjustments are within the capabilities of the skilled person. Reference to the wick being formed from a sintered metal powder does not exclude the wick being formed from a sintered metal powder along with other components.

The starting material for forming the wick is the metal powder. A metal powder comprises at least one metal. This may comprise a nominally pure metal, or it may comprise a metal alloy, or it may comprise a mixture thereof. In particular the metal powder may comprise steel. A particularly preferred alloy is stainless steel, such as 316L stainless steel powder. However, any other suitable metal powder may be used with the invention. In particular, the metal powder may comprise (in nominally pure or alloy form) at least one of iron, silver, copper, gold, platinum, tungsten, titanium, aluminium, vanadium, and niobium.

For enhanced safety, it is preferred that the metal powder comprises a medical grade metal powder, such as the 316L stainless steel noted above. Further common medical grade metals include alloys of titanium, such as titanium aluminium vanadium alloys (for example, Ti-6AI-4V) or titanium aluminium niobium alloys (for example Ti-6AI-7Nb).

The metal powder may consist of any of these metals or metal alloys described herein. For example, the metal powder may consist of a medical grade stainless steel such as 316L.

The metal powder may have a particle size of greater than 5 micrometres, preferably 20 micrometres or greater, or 37 micrometres or greater, most preferably 53 micrometres or greater. The particle size may be 354 micrometres or less, or 250 micrometres or less, preferably 210 micrometres or less, or 125 micrometres or less, most preferably 105 micrometres or less. The particle size may be chosen such as to produce the desired final properties of the wick following sintering. The metal powder may have a particle size that is any range between these upper and lower limits. For example, the particle size may be between 5 micrometres and 354 micrometres, preferably between 37 micrometres and 210 micrometres, most preferably between 53 micrometres and 105 micrometres.

Particle size referred to herein refers to particle size determined by sieve analysis. In this sense, when a lower limit is given for particle size, this refers to at least 90 wt.% of the metal powder, relative to the total weight of metal powder, being retained by a sieve with the corresponding designation. Where an upper limit is given for particle size, this refers to at least 90 wt.% of the metal powder, relative to the total weight of metal powder, passing through a sieve with the corresponding designation. Where both an upper and lower limit are given to provide a range, this refers to at least 90 wt.% of the metal powder, relative to the total weight of metal powder, passing through a sieve with the corresponding designation of the upper limit and being retained by a sieve with a corresponding designation of the lower limit. Preferably all of the metal powder passes through or is retained by the relevant sieve designations described above.

The wick of the present invention is permeable. This means that fluid can be transported across the wick. In other words, the wick has interconnected porosity that forms a continuous path through the wick. In particular, the wick is permeable such that fluid can pass from one side of the wick to the other side of the wick. This permeability can be ascertained as part of the bubble test pore size test.

The wick may have a bubble test pore size of 5 micrometres or greater. This should allow sufficient liquid uptake into the wick to maintain a useful rate of fluid conveyance along the wick. In particular, the wick may have a bubble test pore size of 10 micrometres or greater, or preferably 15 micrometres or greater.

The wick may have a bubble test pore size of 100 micrometres or less. Such a range has been found to be, in particular, effective for use in an electronic nicotine delivery system. In particular, the wick may have a bubble test pore size of 50 micrometres or less, preferably 30 micrometres or less. A large pore size can inhibit the capillary action required to convey the fluid along the wick. The bubble test pore size of the wick may be in the range between any of the lower limits and any of the upper limits noted above. In particular, the bubble test pore size of the wick may be in the range of 5 micrometres to 50 micrometres, preferably 15 to 30 micrometres. Again these ranges have been found, in particular, to be effective for an electronic nicotine delivery system.

The bubble test pore size referred to herein is a method used for the determination of the pore size of permeable sintered powder metallurgical materials. The test is defined in international standard ISO 4003-1977 (E), which is incorporated herein, and is used for defining the capability of the permeable sintered material in relation to fluid transport.

The bubble test pore sizes referred to herein refers to the differential pressure at which constant bubbling first occurs during the bubble test at any point on the surface, i.e. the first bubble point.

When carrying out the bubble test, the test gas is dry and filtered air, and the test liquid utilised is methanol. The test piece is a solid cylindrical test piece, which has the highest point on its surface placed at a depth of 35 mm below the test liquid surface during the test. The rate of pressure increase utilised is preferably 20 Pa/s and the pressure is increased in steps of 50 Pa. The sample is rotated after each step increase in pressure in order to observe the full surface of the test piece.

The porosity within the wick may be substantially uniform. This ensures that the wick has consistent performance throughout the body of the wick. Substantial uniformity means that there are no discernible differences in the porosity distribution throughout the body of the wick. This can be characterised by generalised bubbling (foaming over the whole surface) occurring in the bubble test within 100 Pa of the first bubble point. Substantial uniformity can be imparted by the method of production, where a mixed powder is used as the starting material for the sintering process for forming the complete wick, which is sintered by exposing the whole wick to the same sintering conditions.

Another way of characterising the porosity of the wick is by measuring the wick’s density. The wick may have a density of greater than 50% relative to its theoretical density, preferably greater than 55%. The wick may have a density of less than 80% relative to its theoretical density, preferably less than 70% or less than 65%. In particular, the density of the wick may be between 50% and 80% relative to the theoretical density, preferably between 55% and 65%. The density can be measured in accordance with 1502738:1999 and compared relative to the theoretical density determined by powder x-ray diffraction.

The wick may have an elongate form. This is a convenient shape for transporting fluid within the electronic nicotine delivery system. In particular, the elongate wick can be suitable for transporting a nicotine-containing solution along its length. In this way, the full length of the wick can be utilised in order to convey fluid from one end of the wick to another end of the wick. The wick may have a length of at least 5 mm, preferably at least 10 mm, more preferably at least 15 mm. The wick may have a length of less than 50 mm, preferably less than 35 mm, preferably less than 25 mm. The wick may have a length of between 10 mm and 25 mm or any combination of the upper and lower limits recited herein. The precise dimensions can be varied as required by the particular application. It may have a maximum diameter of at least 0.5 mm, preferably 1 mm. It may have a maximum diameter of less than 10 mm, preferably less than 5 mm. The maximum diameter may be between 1 mm and 5 mm, preferably between 1 mm and 3 mm, although this can be varied as required by the particular application.

The invention further provides a method of forming a wick for an electronic nicotine delivery system, the method comprising the steps of: forming a green body of metal powder; and sintering the green body to form the wick, wherein the wick is permeable.

This method provides a straightforward way in which to produce the advantageous wick of the present invention.

The reference to the green body of metal powder refers to the metal powder in a form that is shaped prior to sintering. For example, the green body may be formed by compacting the powder so that it can retain a shape without support, this self-supporting shape is then sintered to densify the wick. Alternatively, the green body may be constrained within a mould, possibly being compacted as well. The metal powder in the mould is then densified by the sintering process to form the wick. In this way, the wick will adopt the shape of the mould. The mould can be formed from any material that will retain its form at the sintering temperatures being utilised, such as alumina. The maximum temperature utilised during sintering may be below the solidus temperature of the metal powder, such as below 95% of the solidus temperature of the metal powder, or below 90% of the solidus temperature of the metal powder. It may be above 60% of the solidus temperature of the metal powder, preferably above 80% of the solidus temperature. The optimum sintering conditions can be experimentally determined.

The present invention further provides an electronic nicotine delivery system comprising: a housing, wherein the housing is connectable to a mouthpiece; a heater within the housing; and the wick according to the present invention within the housing, wherein the heater is arranged and configured to provide heat to the wick and wherein the wick is configured to extend between the heater and a reservoir containing fluid.

In this way an electronic nicotine delivery device is provided that has the advantages associated with the wick of the present invention, in particular its durability and consistent performance.

The housing may be the outer casing of the electronic nicotine delivery device which the user will be holding when interacting with the device. The housing may be made from a polymer such as ABS or polycarbonate.

As noted above, the housing may be connectable to a mouthpiece. This is particularly useful when one part of the device may be durable and so utilised numerous times while the other part of the device requires regular replacement. For example, the mouthpiece may be a disposable part which requires regular replacement while the housing is retained for further use. This can increase the cost-effectiveness of the device as continual use only requires the replacement of part of the overall electronic nicotine delivery system.

The mouthpiece can be shaped for ease of use by the user. In particular, it can be shaped for placing the user’s mouth over the mouthpiece and thus delivering nicotine to the user. The mouthpiece can interact with the rest of the housing in order to form channels so as to direct the nicotine to the user via the mouthpiece. In particular, the mouthpiece may form channels via which nicotine-containing aerosol can be delivered to the user.

The electronic nicotine delivery device comprises a heater. The heater is used to vaporise nicotine-containing solution in order to deliver nicotine to the user. The heater may take any suitable form. The heater is arranged and configured to provide heat to the wick. In this manner, the heater will heat the nicotine-containing solution so that it can be vaporised and delivered to the user. In doing so, the wick will then be utilised in conveying further nicotine- containing solution towards the heater that will in turn also be vaporised and delivered to the user. In this way, the wick acts to draw nicotine-containing solution from the fluid source to the heater for vaporisation. Accordingly, the wick is configured such that it can extend between the heater, where it will be heated, and the fluid source, such as a reservoir containing the fluid.

It is advantageous for a reservoir containing the fluid to be part of the replaceable part of the system. It is particularly advantageous for the wick to be part of the durable part of the system and thus for the wick to not be regularly replaced. This allows the wick to be used in a manner that fully realises the durability and consistent performance of the wick.

The reservoir and the mouthpiece may be part of the disposable part of the system. In this manner, the mouthpiece is regularly replaced avoiding degradation of this part adversely affecting the user experience. The reservoir may be integrated with the mouthpiece, i.e. may be formed as one piece that is replaced as one piece when required. This may be termed as a cartridge assembly, which may in addition have one or more of the other features that is described herein in relation to a cartridge assembly.

The heater may be arranged to be around the wick, i.e. the heater may surround part of the wick. The heater may surround the wick along a portion of its length. In this way, the heater provides heat to a larger surface area of the wick, and this assists in the vaporisation of the fluid that is conveyed by the wick. In particular, the heater may be cylindrical and part of an elongate wick can be present within the cylinder. The heater may be a heating element encapsulated in an inert material, such as a ceramic.

It is noted that when the wick is part of the durable part of the system and the reservoir is part of the replaceable part of the system, the durability of the wick and its structural rigidity is useful as the wick will have to be inserted into different reservoirs multiple times. The wick is a rigid wick that has sufficient rigidity to maintain its own shape, without external support, when inserted into the reservoir, especially over the course of repeated insertions. This is a particularly advantageous aspect of the present invention. The reservoir is configured to receive the wick. The reservoir may comprise a port to allow the insertion of the wick therethrough. The port is an opening allowing the wick to enter the reservoir and contact the nicotine-containing solution contained within. When the reservoir has a top wall, bottom wall and side walls, the port may be in the bottom wall of the reservoir.

The interior volume of the reservoir may comprise a fibrous material or a sponge, wherein the fibrous material or sponge contains the nicotine-containing solution. This is a convenient way of retaining the solution within the reservoir until contacted by the wick during use. The fibrous material or sponge may be saturated with the solution. A fibrous material is one that comprises a plurality of fibres. A sponge is a continuous matrix of material with an open porosity that can retain the composition.

Particularly effective fibrous materials and sponges have been found to comprise polymeric materials, such as thermoplastic polymeric materials. Such polymeric materials include polyesters, in particular thermoplastic polyesters. Useful thermoplastic polyesters include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). The fibrous material or sponge in the reservoir may consist of only one material, such as the polymeric material. This reduces the risk of producing contaminants within the nicotine-containing solution.

As noted, the electronic nicotine delivery system comprises the electronic nicotine delivery device along with the mouthpiece and the reservoir. The reservoir may be integrated with the mouthpiece. The mouthpiece and/or the reservoir may be integrated with the electronic nicotine delivery device (i.e. not be separate or separable components). In such an embodiment it would not be possible to individually replace those components. In particular, when the whole system is integrated together, the whole system will need to be replaced when required.

The reservoir may be designed to be refilled from an external source. This can be useful when the reservoir is integrated with the electronic nicotine delivery device.

The present invention also relates to the use of a wick described herein in an electronic nicotine delivery system. In particular, the present invention relates to the use of a wick described herein for conveying a nicotine-containing solution, in particular in an electronic nicotine delivery system. The present invention further provides a method of conveying liquid, particularly a nicotine- containing solution, with a wick described herein within an electronic nicotine delivery system. The method comprises vaporising the conveyed liquid to result in further conveyance of liquid due to capillary action. This can occur between a liquid reservoir and a heater within the electronic nicotine delivery system.

The present invention has focussed on the fluid conveyed by the wick being a nicotine- containing solution. However, that does not need to be the case and the fluid could be an alternative fluid that is desired to be vaporised within the device for delivery to the user.

The wick of the present invention is particularly suited to be utilised with an electronic nicotine delivery system that can be characterised as a regulated medical device. This is due to the wick’s durability and consistent performance. To be able to introduce onto the market the device and the cartridge containing the nicotine composition as a medical device, all the components as well as the nicotine composition and the chemicals must be made under good manufacturing practices (GMP) and thus there are higher demands compared to entering onto the market with for example an E-cigarette.

The invention will now be described with respect to the following figures.

Fig. 1 is a schematic perspective view of a cartridge assembly.

Fig. 2 is a schematic side view of the cartridge assembly of Fig. 1.

Fig. 3 is a schematic side view of the cartridge assembly of Fig. 1.

Fig. 4 is a schematic side view of the cartridge assembly of Fig. 1.

Fig. 5 is a cross-section of the cartridge assembly of Fig. 1.

Fig. 6 is a cross-section of the cartridge assembly of Fig. 1.

Fig. 7 is a second exploded diagrammatic view of the cartridge assembly.

Fig. 8 is a schematic perspective view of the electronic nicotine delivery device for the delivery of nicotine from a cartridge assembly as shown in Figs. 1 to Fig. 6.

Fig. 9 is a diagrammatic representation of the electronic nicotine delivery system.

Fig. 10 is a cross section view of the electronic nicotine delivery system of Fig. 9.

Fig. 11 is a partial cutaway perspective view of the electronic nicotine delivery system of the present invention of Fig. 9.

Fig. 12 is the appearance of the sintered wicks following varying numbers of puffs. Fig. 13 is the mass loss due to conveyance of fluid through the wick during one dose taken after various numbers of puffs.

Fig. 14 measures the mass loss from the reservoir during a single dose.

Definitions

In the context of the present application the following definitions apply:

The calculation of the amount of nicotine present in the composition is calculated as the free base form of nicotine.

The term “% w/w” is intended to mean the weight percentage of an ingredient relative to the total weight of the composition.

The term “cycle” means the time period that starts from when the user starts inhaling, then the heater in the device starts heating up, and heats the nicotine composition, the nicotine composition becomes vaporized/aerosolized and transferred from the device through the mouth piece into the human being and then the device is turned off. The cycle may take about 30 seconds to one minute.

NICOTINE-CONTAINING SOLUTION

The nicotine-containing solution composition that is suitable for use with the wick of the present invention has been developed to fulfil a number of criteria; being completely aerosolized/vaporized to provide a specific amount of nicotine in one cycle as defined above to give craving relief, i.e. , 2-6 mg in one cycle, and no visible smoke since the medical device should not be associated with a cigarette. In addition no unhealthy compounds, such as fragrances and flavors should be included.

The nicotine-containing composition may comprise, consist essentially of or consist of nicotine or a salt thereof in an amount of from about 2 % w/w to about 6 % w/w, propylene glycol in an amount of from 50 % w/w to about 65 % w/w and water in an amount of from about 35 % w/w to about 50 % w/w. The composition should be substantially free from other chemical compounds, such as no other chemical compounds should be present in the composition to reduce the possibility to develop toxic compounds when the composition is heated up. The amount of nicotine in the composition may vary depending on how addicted the user is and is and may be from about 2 %w/w to about 6 %w/w such as 2 %w/w, 3 %w/w, 4 %w/w, 5 %w/w or 6 %w/w.

The propylene glycol is present from 50 %w/w to 65 %w/w, such as 55 %w/w to 60 %w/w,

56 %w/w, 57 %w/w, 58, %w/w, 59 %w/w, 60 %w/w, 61 %w/w, 62 %w/w, 63 %w/w, 64 %w/w or 65 %w/w. Alternatively, the amount of propylene glycol may be less than 20 %w/w.

The water is present in an amount from about 35 %w/w to about 50 %w/w, such as 36 %w/w, 37 %w/w, 38 %w/w, 39 %w/w, 40 %w/w, 41 %w/w, 42 %w/w, 43 %w/w, 44 %w/w, 45 %w/w, 46 %w/w, 47 %w/w, 48 %w/w or 50 %w/w.

Examples of nicotine salts include, but are not limited to, formic (2:1), acetic (3:1), propionic (3:1), butyric (3:1), 2-methylbutyric (3:1), 3-methylbutynic (3:1), valeric (3:1), lauric (3:1), palmitic (3:1), tartaric (1:1) and (2:1), citric (2:1), malic (2:1), oxalic (2:1), benzoic (1:1), gentisic (1:1), gallic (1:1), phenylacetic (3:1), salicylic (1:1), phthalic (1:1), picric (2:1), sulfosalicylic (1:1), tannic (1:5), pectic (1:3), alginic (1:2), hydrochloric (2:1), chloroplatinic (1:1), silcotungstic (1:1), pyruvic (2:1), glutamic (1:1), and aspartic (1:1) salts of nicotine. While the use of the free base of nicotine is generally preferred, the use of such salts may be desirable to lower the pH to potentially reduce irritation for liquid formulations containing a high concentration of nicotine.

The nicotine composition is free from glycerol, ethanol, flavor, fragrances or other ingredients to be as safe as possible and not to produce any toxic compounds during the use of the cartridge in the medical device cycles.

CARTRIDGE

In accordance with the present invention, as illustrated in Figs. 1-11, a cartridge assembly (1) for a medical electronic nicotine delivery device (2) is disclosed. The cartridge assembly (1) comprises a body assembly (3) with a reservoir (4) configured to hold a nicotine composition. The reservoir (4) may be elongate. The bottom of the cartridge may include a plug (10), described in greater detail below with respect to Fig. 7, which is removably retained in the port or wick opening (6b) prior to use and is removed for use. The cartridge assembly (1) is preferably made of a medical grade, chemical resistant material, such as a thermoplastic material. The cartridge assembly (1) may be made from any suitable nicotine resistant polymeric material or metallic material, including stainless steel. The wick (11) is chemically resistant to nicotine, is temperature resistant, and is rigid to prevent collapse during insertion into the reservoir (4) or during use. A more detailed description of the wick (11) is given below. A fibrous material or sponge (9) or any liquid holding element may be arranged in the reservoir (4) and extends to a position close to the first/bottom end of reservoir (4). When the wick (11) has been pushed into the cartridge assembly (1) the fibrous material/sponge (9) can engage the wick (11) so as to allow fluid present in the reservoir (4) to be transported through the wick (11) to the heater (32), preferably an electric heater or heating element, within the receptacle (39) of the housing (26) of the electronic nicotine delivery system (2).

The cartridge assembly (1) as set forth herein is arranged to be suitable for use in a medical electronic nicotine delivery device (2).

The body assembly (3) comprises, two air-let channels/conduits (12) that extend within the body assembly (3) exterior to and along the reservoir (4).

As set forth above, a single use, tamper resistant cartridge assembly (1) is utilized as an integral component in an electronic nicotine delivery system (2) for smoking cessation. Referring, in greater detail, to Figures 1 - 11, there is illustrated a cartridge assembly (1) in accordance with the present invention. In one exemplary embodiment, the cartridge assembly (1) comprises a body assembly (3) having an interior surface defining an interior volume. The interior volume of the body assembly (3) includes a reservoir (4), the reservoir (4) having top wall (5) with an optional opening (6a) formed therein, a bottom wall, and side walls (7) having an inner surface and an outer surface, the inner surface of the side walls (7) defining an interior volume (9) of the reservoir (4). The interior volume (9) of the reservoir (4) may comprise a nicotine saturated fibrous material (8) or a sponge therein.

The cartridge assembly (1) also includes a port (6b) formed in the bottom wall of the body assembly (3) of the reservoir (4) to allow insertion of a wick (11) from the electronic nicotine delivery device (2). The cartridge assembly (1) further includes two conduits (12) formed between the outer surface of side walls (7) of the reservoir (4) and the interior surface of the body assembly (3), the conduits (12) having open top ends (13) proximate the top wall (5) of the reservoir (4) and open bottom ends (14) proximate the bottom wall of the reservoir (4). The conduits (12) are configured for holding and distributing aerosolized nicotine as is explained in much greater detail subsequently.

The cartridge assembly (1) still further includes a manifold (15) positioned above the top wall

(5) of the reservoir (4), the manifold (15) is configured for holding and distributing aerosolized nicotine. In one embodiment, the manifold (15) includes an open top end (16), two open bottom ends (17), and two interior channels (18) connecting the open top end (16) to the open bottom ends (17), wherein the open bottom ends (17) of the manifold (15) being secured onto the open top ends (13) of the conduits (12) of the cartridge assembly (1) so as to form a continuous path from the open top end (16) to the open bottom ends (14) of the conduits (12) for communicating the aerosolized nicotine.

The cartridge assembly (1) still further includes a mouthpiece (19) positioned above the manifold (15), having an outlet (20) in fluid communication with the interior channels (18) of the manifold (15). The mouthpiece (19) being configured for delivering aerosolized nicotine into the mouth of a user. The mouthpiece (19) may be secured to the body assembly (3) via any suitable means, including snap fit features (42) as illustrated in detail in Figs. 1-4 and 7.

The cartridge assembly (1) further includes at least one of an anti-counterfeit element (22) and an anti-reuse element (21) mounted to the outer surface of the body assembly (3). The anti-counterfeit element (22) is configured to preclude use of an unauthorized cartridge assembly in the electronic nicotine delivery system (2) while the anti-reuse element (21) is configured to preclude reuse of the cartridge assembly (1) once removed from the electronic nicotine delivery system (2) as illustrated in Figs 1 and 7.

Referring to Fig. 11, there is illustrated a female mating component (34) in receptacle (39) of housing (26) of medical electronic nicotine delivery device (2) that interlocks with male component (35), illustrated in Fig. 1, on an outer surface of the body assembly (3) of the cartridge assembly (1). These female/male components may comprise any suitable shape or any suitable mechanisms for locking the cartridge assembly (1) to the electronic nicotine delivery device (2).

In Figure 7 there is illustrated a plug (10) which covers the open bottom part of the cartridge sealing the reservoir (4) , so that the composition held in the reservoir (4), will be maintained within the reservoir (4) and protected from contamination. The plug (10) may be formed from any suitable material that is resistant to nicotine/nicotine composition. The plug (10) is configured to prevent accidental leakage of the nicotine/nicotine composition contained in the reservoir (4).

As set forth above, more particular descriptions of the cartridge assembly (1) and the medical electronic nicotine delivery device (2) is given herein as well as a description of the nicotine formulations and operation of the device.

Referring again in general to Figs. 1-11, the cartridge assembly (1) comprises at a first/bottom end including a plug (10) and at a second/top end opposite to the first/bottom end a mouthpiece (19). A reservoir (4) is provided in a body assembly (3) between the first end and the second end. In various exemplary embodiments, the body assembly (3) is elongate and comprises an elongate passage extending from first end of body assembly (3) to second end of body assembly (3). The reservoir (4) is arranged at a central position between conduits/air-let channels (12) forming the elongate passage. The two conduits/air- let channels (12) extend along opposite sides of the reservoir (4) from open bottom ends (14) to two interior channels (18) in the manifold (15). The mouthpiece (19) promotes a favorable tactile response for the user. The cartridge assembly (1) is usable for a period of time until the nicotine composition has been consumed after which the cartridge is replaced and a new cartridge is inserted into the device (2). The mouthpiece (19) may be integral with the rest of the cartridge assembly (1).

Open bottom ends (14) extend to the air-let channels/conduits (12). The two interior channels (18) merge into an open top end (16) in the manifold (15), forming an inhalation opening present in the mouthpiece (19) where a user inhales the nicotine aerosol. The two interior channels (18) allow air to pass in or out, such as aerosol from the nicotine composition present in the reservoir. The two interior channels (18) will mix the nicotine aerosol efficiently when passing therethrough.

The wick (11) may extend into the reservoir (4) when the cartridge assembly (1) is inserted into the medical electronic nicotine delivery device (2) to facilitate transfer of nicotine from the reservoir (4) to the heater (32) within the receptacle (39) of the housing (26) of the medical electronic nicotine delivery device (2) when the plug (10) is removed. The wick (11) is inserted and penetrates into interior volume (9) of reservoir (4) to contact the nicotine composition contained in the reservoir. A nicotine saturated fibrous material (8) may be disposed within interior volume (9) of reservoir (4) and the wick (11) is configured to contact the nicotine saturated fibrous material (8) in order to transfer nicotine from the fibrous material (8) to the heater (32) within the receptacle (39) of the housing (26) and the heater (32) will heat up the nicotine composition so that it will be vaporized to form the aerosol and inhaled by a person using said device and the person will get a craving relief from smoking. In one exemplary embodiment, the fibrous material (8) is made of a porous material such as thermoplastic polymer, for example a polyester. Further, examples are polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or a mixture thereof or a mesh as well as stainless steel. It is important to note that any suitable material may be utilized.

The anti-reuse element (21) may include a plurality of springs 27, which are configured to be disrupted, changed, or damaged upon removal of the cartridge assembly (1) from the electronic nicotine delivery system (2). By introducing such anti-reuse feature, i.e. the spring being destroyed by member (37) during withdrawal of cartridge assembly (1) from the receptacle (39) of the housing (26) of the medical electronic nicotine delivery device (2), the risk of the cartridge assembly (1) being reused is minimized. Minimizing the risk of cartridge assembly (1) reuse, prevents refilled or otherwise altered cartridges to be used with the medical electronic nicotine delivery device (2).

The fibrous material (8) may be formed as one or more piece(s) substantially filling out the full interior volume (9) of reservoir (4). When the wick (11) engages or penetrates the fibrous material (8) it will start transporting the solution present within the reservoir (4) out of the reservoir (4). The wick (11) may be soaked or saturated with the nicotine composition. The fibrous material (8) may comprise one fibrous material unit.

Mouthpiece (19) extends in two opposite flaps (36) that will fit smoothly with a receptacle (39) of the housing (26) of the electronic nicotine delivery device (2) (see Fig. 8). Flaps (36) provide a comparatively rigid connection between the cartridge assembly (1) and the receptacle (39) of the housing (26) when the cartridge assembly (1) is fully inserted in the receptacle (39) of the housing (26). Body assembly (3) of cartridge assembly (1) may be provided with a tamper protection device or an anti-counterfeit element (22). The anti counterfeit element (22) may comprise a plurality of electrically conducting pads (23) (e.g. three pads) arranged at predetermined exterior positions on body assembly (3). It is important to note that the plurality of pads (23) are in a particular configuration; for example, a linear arrangement. In alternate approaches, a different number of pads (23) may be utilized in any suitable configuration that matches the electrical contact elements (24) on the inside of the receptacle (39) of the housing (26) (see Fig. 11). When the cartridge assembly (1) is inserted into the receptacle (39) of the housing (26), the three pads (23) make contact with electrical contact elements (24), which complete a circuit that measures resistance. Essentially, when the cartridge assembly (1) is moved relative to and within the receptacle (39) of the housing (26) the anti-counterfeit element (22) is affected by matching electrical contact elements (24) on the inside wall of receptacle (39) of the housing (26). Any simple circuit for measuring resistance may be utilized, for example, a Wheatstone bridge. If the resistance matches the preset resistance value programmed into the controller of the electronic nicotine delivery device (2), the cartridge assembly (1) is the proper one for the medical electronic nicotine delivery device (2) and the medical electronic nicotine delivery device (2) will work. If the resistance does not match, the cartridge assembly (1) is not the proper one for the medical electronic nicotine delivery device (2) and the medical electronic nicotine delivery device (2) will not work. It is important to note that the plurality of pads (23), for example three pads (23), may have equal resistance values, or different resistances values. What is measured is the total resistance when the circuit is completed by the insertion of the cartridge assembly (1) into the receptacle (39) of the housing (26). Other electrical characteristics may be measured in place of, or in addition to, the resitance values, for example, capacitance. Once again there are well known simple circuits that may be utilized to measure capacitance as well as any number of other electrical parameters. The plurality of electrical contact elements (24) may be made from any suitable material and mounted to circuit board (25) by any suitable means. The choice of material is determined by the selected parameter to be measured which may also impact the means of attachment of the plurality of electrical contact elements (24) to the circuit board (25).

The cartridge assembly (1) and medical electronic nicotine delivery device (2) may comprise anti-reuse feature(s) as briefly set forth above. A plurality of springs (27) may be positioned in such a configuration/position that permits contact with plurality of electrical pads (28) (see Fig. 11) inside receptacle (39) of the housing (26). In this position/configuration, it is possible to determine electrical properties, such as an electrical resistance, between the plurality of springs (27). A circuit board (25) within receptacle (39) of the housing (26) contacts the plurality of springs (27) at electrical pads (28) when the cartridge assembly (1) is in position inside the receptacle (39) of the housing (26) and determines preset electrical properties. More specifically, the plurality of springs (27) make contact with elements within the receptacle (39) of the housing (26) in order to complete the circuit when the cartridge assembly (1) is inserted into receptacle (39) of the housing (26). The controller within the medical electronic nicotine delivery device (2) determines that the circuit is complete by measuring a particular electrical parameter such as resistance; however, other parameters may be utilized. Upon removal of the cartridge assembly (1) from the receptacle (39) of the housing (26), one or more of the plurality of springs (27) (e.g. one or both springs (27) when two springs are present) are bent out of the way by a member (37) of the receptacle (39) of the housing (26) such that if re-inserted, the bent spring(s) (27) will no longer make contact with corresponding electrical pads (28) in the receptacle (39) of the housing (26) and the circuit will not be complete. The member (37) that bends the one or more springs (27) may be a simple wedge-like protrusion that only bends the springs (27) upon removal of the cartridge assembly (1). Alternatively, one or more springs (27) may be broken off rather than simply bent; however, a piece of the spring (27) may fall into the receptacle (39) of the housing (26) and become stuck therein. Preferably, the springs (27) may comprise any suitable conductive material that is pliable or bendable. In an embodiment where the springs (27) are designed to break rather than to bend, the springs (27) may be formed from a conductive but brittle material. In addition, in alternative exemplary embodiments, the springs (27) may be replaced with any suitable conductive material that forms a complete circuit when properly aligned, for example, a conductive foil that tears away when the cartridge assembly is removed from the receptacle (39) of the housing (26).

The receptacle (39) of the housing (26) may be arranged with an internal edge that will separate the springs (27) when the cartridge is removed from the receptacle (39) of the housing (26). If the same cartridge assembly (1) is inserted again, the electrical pads (28) mounted on circuit board (25) will not contact the springs (27) correctly and the electrical properties as determined by the electronic circuit will not correspond to the stored data. As a result, the medical electronic nicotine delivery device (2) will not be enabled for proper use.

The cartridge assembly (1) and the different components thereof should be made from a material that is resistant against nicotine or salts thereof. Examples of materials include any kind of polymeric materials such as polyester, polyacrylonitrile (PAN) resin (Anobex™), cyclic olefin copolymer or High-Density polyethylene (HDPE). The cartridge assembly (1) as defined above may be sealed at the bottom end by the plug (10) and the body assembly (3) and the mouthpiece (19) to prevent environmental particles from entering into the cartridge assembly (1) during storage and transportation.

While the foregoing description and drawings represent exemplary embodiments of the present disclosure, it will be understood that various additions, modifications and substitutions may be made therein without departing from the spirit and scope and range of equivalents of the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, sizes, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. In addition, numerous variations in the methods/processes described herein may be made within the scope of the present disclosure.

OPERATION

Referring back to Figs. 1-11, the medical electronic nicotine delivery device (2) includes a power source (31) and a heater (32), preferably an electric heater or heating element, contained within a receptacle (39) (see Fig 11). The receptacle (39) has at least one air inlet (38), see Figs. 9 and 10, and provides holes, see Fig. 10, proximate the bottom wall of the body assembly (3), described in detail above, and proximate the heater (32). When assembled, the receptacle (39), heater (32), and cartridge assembly (1) cooperate to form a vaporization chamber (33) (see Fig. 11). The assembled electronic nicotine delivery system (2) also provides a predetermined airflow from the at least one air inlet (38) through the vaporization chamber (33), the conduits (12) and to the outlet (20) of the mouthpiece (19) to permit a user to inhale the nicotine aerosol formed therein. In addition, the assembled medical electronic nicotine delivery device (2) provides a liquid conduit from the reservoir

(4) to the heater (32) in the form of a wick (11), more preferably an elongate wick, as described herein. The housing (26) may also provide for connectivity to an outside electrical source and/or data communication, such as a micro-USB port (40), see Fig. 10, to supply and/or resupply the power source (31), preferably a rechargeable battery.

The power source (31) is sufficient to power the heater (32), a programmable controller (not shown), and any desired feedback to a user (e.g., light), external computer, or network. The programmable controller receives information from a pressure sensor (detecting inhalation by a user), and, possibly, other sensors (such as temperature sensors) to control the power delivered to the heater (32), and controls over temperature sensor(s), which can terminate power to the heater (32) to prevent undesirable and/or dangerous thermal events. The programmable controller may provide for data collection, storage and communication to the external computer. This may be communicated through a wireless connection. The power source (31) can be any appropriate portable power source (31) such as a primary or secondary battery or fuel cell.

The heater (32) is mounted on a holder (41) to isolate electrical resistance heater elements from other, thermally sensitive components of the medical electronic nicotine delivery device (2). The holder (41) may be formed from any suitable material with sufficient mechanical characteristics to support all elements attached thereto while providing an insulative function, i.e. low thermal conductivity. The heater (32) comprises at least one electrical resistance heater element contained in a heat diffusing material. The diffusion of the heat through the heat diffusing material generally evens out heat profile generated by the heating element(s) to prevent the formation of localized hot spots on the heater (32) surface.

As indicated above, the cartridge assembly (1) preferably includes a reservoir (4) containing a nicotine composition and a mouthpiece (19) for drawing a nicotine aerosol from the medical electronic nicotine delivery device (2). In addition, the assembled medical electronic nicotine delivery device (2) provides a liquid conduit from the reservoir (4) to the heater (32). The liquid conduit is a wick (11) (optionally an elongate wick) extending from the reservoir (4) to the heater (32). The wick (11) intimately contacts the heater (32) surface to enable the thermal energy to vaporize the nicotine composition transported thereto by the wick (11). As the nicotine composition is vaporized, the wick (11) transports additional nicotine composition to the heater (32) through capillarity.

The assembled medical electronic nicotine delivery device (2) also provides a vaporization chamber (33) proximate the heater (32). It is in the vaporization chamber (33) that the heater (32) vaporizes the nicotine composition transported by the wick (11) and in which the vaporized nicotine composition combines with outside air drawn in through one or more air inlets (38) to form a nicotine aerosol. The vaporization chamber (33) also communicates with the outlet (20) of the mouthpiece (19) via the interior channels (18) in the cartridge assembly (1) to permit a user to draw the nicotine aerosol into his or her mouth.

When a user draws air through outlet (20) from the mouthpiece (19), negative pressure causes air to flow into the assembled medical electronic nicotine delivery device (2) through one or more air inlets (38). In particular, air is withdrawn from the vaporization chamber (33) through the conduits (12) and the interior channels (18), lowering the air pressure in the vaporization chamber (33). The withdrawn air is replaced via air inlets (38) in the housing (26), proximate the vaporization chamber (33). The lowered air pressure in the vaporization chamber (33) is sensed by a pressure sensor disposed on the printed circuit board (43), outside of the vaporization chamber (33). The lower air pressure proximate the pressure sensor activates an operatively coupled switch with pressure sensor. This pressure sensor, in turn, activates the heater (32), which in turn heats the nicotine composition in contact therewith on the surface of the wick (11). The nicotine composition is vaporized and combined with air in the vaporization chamber (33), forming a nicotine aerosol. The nicotine aerosol is evacuated from the vaporization chamber (33) through the conduits (12) and interior channels (18) and delivered to the mouthpiece (19) and, ultimately, the user’s mouth. As the nicotine composition is vaporized, additional solution is drawn from the reservoir (4) along wick (11) to heater (32). The volume of nicotine composition removed from reservoir (4) is replaced by air drawn through the at least one air inlet (38). In one exemplary embodiment, after a predetermined time (e.g., determined by the programmable controller), the power to the heater (32) is terminated, the vaporization chamber (33) cools, and no further nicotine aerosol is formed. The user will then stop drawing on the medical electronic nicotine delivery device (2), ending his/her “treatment”. Alternatively, the user may stop drawing on the medical electronic nicotine delivery device (2) prior to the predetermined time. In such a case, the pressure in the vaporization chamber (33) will return to atmospheric pressure and the pressure sensor will signal switch to terminate power to the heater (32).

In a final aspect the invention relates to a medical electronic nicotine delivery device (2), including a housing (26), a cartridge assembly (1) as defined above, an electrical module (30), a power source (31), a heater (32), and a vaporization chamber (33).

WICK

The wick (11) may be dimensioned appropriately to interact with the other features as part of the medical electronic nicotine delivery device. For example, it can be of a solid cylindrical form, having a length of 17 mm and a diameter of 2.1 mm.

An initial assessment of the performance of the wick of the present invention was conducted by forming sintered metal wicks from 316L stainless steel metal powder which were anticipated to give pore sizes of 10, 20, and 50 micrometres. These wicks were used in an electronic nicotine delivery device of the form in the figures to convey nicotine-containing solution from a reservoir to a heater and the administration of up to 20 doses was simulated. A single puff involves a 3 second activation of the device to vaporise nicotine-containing solution that has been conveyed through the wick from the reservoir, followed by a pause of 27 seconds before commencing the next puff. A dose consists of 10 of these puffs. The mass of solution that is lost from the reservoir for each dose was measured and is presented in Fig. 12. As can be seen, all of the wicks are able to convey fluid to be vaporised throughout the test. However, the most consistent behaviour appears to be with the nominal 10 micrometre pore size sample and the least consistent behaviour occurred with the 50 micrometre sample.

In order to assess the actual pore size, the samples that had nominal pore sizes of 10 and 20 micrometres were subjected to the bubble test method. This bubble test measurement gave a pore size of 35.0 micrometres for the sample that was nominally a 20 micrometre pore size sample and a pore size of 28.3 micrometres for the sample that was nominally a 10 micrometre pore size.

In order to further assess the performance of the wicks of the present invention, wicks were sintered from stainless steel 316L powder having a particle sizes in the range of 53 micrometres to 105 micrometres. The powder was placed in cylindrical cavities in an alumina block and subjected to sintering at a maximum temperature of 1230 °C where it is held for 2 hours. The resulting wick pore sizes were determined using the bubble test method. The determined pore size for the wicks ranged from 18.86 to 19.95 micrometres.

These wicks were used in the electronic nicotine delivery device of the form illustrated in the figures and subjected to cycles of up to 30,000 simulated puffs. Again, a single puff involves a 3 second activation of the device to vaporise nicotine-containing solution that has been conveyed through the wick from the reservoir, followed by a pause of 27 seconds before commencing the next puff.

The appearance of some of these wicks initially, and then after 1000, 5000, 10000, 15000, 20000, 25000, and 30000 puffs is illustrated by Fig. 13. These pictures illustrate the wick enclosed within the heater, which is the area of the wick from which the vapour is produced. It can be seen that there is no discernible change in the appearance of the wick illustrating a lack of degradation and no clogging of the pores. The consistent performance is further demonstrated in Fig. 14, which measures the mass loss from the reservoir during a single dose. This is measured initially, and then at 5000 puff intervals up to 30000 puffs. It can be seen that all of the wicks have consistent performance, showing no particular degradation in the ability to convey and vaporise fluid from the reservoir.

One skilled in the art will further appreciate that the embodiments may be used with many modifications of structure, arrangement, proportions, sizes, materials, and components and otherwise, used in the practice of the disclosure, which are particularly adapted to specific environments and operative requirements without departing from the principles described herein. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive. The appended claims should be construed broadly, to include other variants and embodiments of the disclosure, which may be made by those skilled in the art without departing from the scope and range of equivalents.

Claims

1. A wick for an electronic nicotine delivery system, wherein the wick is formed from a sintered metal powder, and wherein the wick is permeable.

2. The wick according to claim 1 , wherein the wick has a bubble test pore size of 5 pm or greater.

3. The wick according to any preceding claim, wherein the wick has a bubble test pore size of 100 pm or less.

4. The wick according to any preceding claim, wherein the porosity is substantially uniform throughout the wick.

5. The wick according to any preceding claim, wherein the wick consists of sintered metal powder.

6. The wick according to any preceding claim, wherein the wick has an elongate form.

7. The wick according to claim 6, wherein the wick is suitable for transporting a nicotine-containing solution along its length.

8. The wick according to claim 6 or claim 7, wherein the wick has a length of between 10 mm and 25 mm.

9. The wick according to any preceding claim, wherein the metallic powder comprises stainless steel.

10. A method of forming a wick for an electronic nicotine delivery system, the method comprising the steps of: forming a green body of metal powder; and sintering the green body to form the wick, wherein the wick is permeable.

11. An electronic nicotine delivery device comprising: a housing, wherein the housing is connectable to a mouthpiece; a heater within the housing; the wick according to any preceding claim within the housing, wherein the heater is arranged and configured to provide heat to the wick, and wherein the wick is configured to extend between the heater and a reservoir containing fluid.

12. The device according to claim 11 , wherein the heater is arranged around the wick.

13. The device according to any one of claims 11 or claim 12, wherein the reservoir contains a nicotine-containing solution.

14. The device according to any one of claims 11 to 13, further comprising the mouthpiece, wherein the housing is connected to the mouthpiece.

15. The device of any one of claims 11 to 14, further comprising the reservoir, wherein the reservoir is integrated with the mouth piece.

16. An electronic nicotine delivery system comprising: the electronic nicotine delivery device of any one of claims 11 to 13; the mouthpiece; and the reservoir, wherein the reservoir is integrated with the mouth piece.