Smokeless tobacco product

Abstract

A nonaqueous, extrudable composition includes at least one thermoplastic polymer in an amount of more than 20 wt % of the whole composition and tobacco. A smokeless tobacco product in the form of a sheet can be made by extruding or hot melt shaping a nonaqueous composition comprising at least one thermoplastic polymer and tobacco, the sheet being soluble in a user's mouth and resulting in sustained release of nicotine to the user. The sheet can be in a form that may be placed in the buccal cavity of, on the palate of or sublingually in the user, and have an average dissolution time of 5 to 50 minutes for delivering super bioavailable nicotine to the user.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates, inter alia, to a smokeless tobacco product, an extrudable tobacco composition, a method for manufacturing a smokeless tobacco product and a method for delivering nicotine contained in tobacco to a user.[0002]American consumption of smokeless tobacco is growing while cigarette smoking is declining. Awareness of the potential health risks of smoking, the potential risks of second hand smoke to third parties, and the increasing existence of cigarette smoking bans are all factors that are helping to shift tobacco consumption from cigarettes to smokeless tobacco. U.S. sales of moist snuff increased 10% in 2006 after several years of 6% growth while cigarette consumption declined. Another potential contributing factor to this shift is the increasingly held view in the public health community that smokeless tobacco may be much less harmful to the health of the user than is cigarette smoking. In addition smokeless tobacco does ...

AI Technical Summary

Benefits of technology

[0049]The present invention also relates to a smokeless tobacco product comprising a sheet made by extruding or hot melt shaping a nonaqueous composition comprising at least one thermoplastic polymer and tobacco, the sheet comprising a matrix comprising the at least one thermoplastic polymer and the tobacco distributed in the matrix, the matrix being soluble in a user's mouth and resulting in sustained release of nicotine to the user.

Problems solved by technology

Despite this fact, US smokers are generally reluctant to try smokeless tobacco products.

Traditional smokeless tobacco products frequently appear to be moist and dirty.

Moreover, American consumers generally react poorly to traditional smokeless tobacco products when they do try such products.

It can be assumed that reactions may even be less favorable in countries which do not, like the U.S., have an incidence of modern smokeless use.

Regardless of whether tobacco is lose or in pouches, it is generally brown, often moist and is considered unsightly and unappealing by many smokers who are reluctant to use smokeless tobacco products.

However, no methods of enhanced nicotine absorption from amount of tobacco have been taught.

In addition the pouch wall also serves as an obstruction to nicotine outflow from the tobacco.

High viscosity is a limitation of aqueous casting.

The art has tended to move from wet casting towards extrusion—for reasons of throughput and cost.

Removing moisture from a wet cast film requires substantial amounts of heat energy.

As energy costs have escalated the cost of removing excess water has increasing cost implications.

But applicant has found that it is not helpful in connection with a sustained release dissolving tobacco sheet.

This is because the inherent properties of the wet casting manufacturing process—as currently understood—do not allow for the manufacture of thicker sheets.

Wet cast edible films are typically quickly dissolving products, and practitioners have struggled—and not with great success—to extend the disintegration time of wet cast edible film products where a slower dissolving product would be more appropriate for the intended use.

One of the principle problems is that polymer molecular weight is frequently in a direct relationship to viscosity and wet casting is unable to deal with high viscosities.

The product contains high moisture content and uses water to help impart the product with flexibility (a trait easily demonstrated by drying a Listerine strip—at which point it becomes very brittle and will crack and break when bent).

It should be noted that these descriptions of the wet cast products do not address whether the active material is water soluble or insoluble and whether it requires taste masking or does not require taste masking.

One limitation of wet cast technology is the difficulty—indeed, the inability to wet cast films beyond a certain thickness (or loading) range.

This is due to the relationship between viscosity and coating thickness, which creates a practical limitation on the ability to coat beyond certain thickness levels, and the difficulty removing moisture from films past a certain thickness levels, even if they are successfully cast.

Likewise, limitations on thickness also limit the extension of dissolution time of the film matrix.

That such a practice would involve immense challenges—arguably impossible—to scale to commercial manufacture is readily apparent.

This method is undoubtedly more practical from a manufacturing perspective than Fankhauser's proposed solution, but too costly to practice—even in the pharmaceutical space.

As a result, such multiple film laminates are not seen in the marketplace as commercial products.

Even monolayer wet casting can be relatively expensive.

Commercial equipment involves long drying ovens and is too heavy to be moved, requiring specialized and dedicated production suites.

These costs may be born by pharmaceutical products but can be challenging in the cost competitive global tobacco field.

However additional costs and process steps to include the use of a substrate backing are involved.

If such films lack the requisite pliability and tensile strength, they will tend to break during packaging causing substantial losses in process yield.

The reality is that physical strength and resulting breakage and process yield issues have been significant problems for many of the non-PEO films.

The related issue of physical stability is also an issue for many wet cast films—expensive barrier packaging is often used as a matter of necessity.

Still, physical stability is not always a given.

Boots Chemists launched a Vitamin C strip manufactured by BioProgress in Tampa Fla. that had to be removed from the shelves because it was crumbling in the package—earning the name “chips not strips.” This story is not unique—many projects have failed to move out from development to commercialization due to physical stability issues.

In addition, the mixing of wet based compositions for casting itself raises certain challenges.

First, the solvent itself adds volume to the mix.

Wet compositions may tend to adhere to mixing vessels and any transit piping leading to yield losses.

Foaming may be in issue.

Extrusion has more recently been used in medical device manufacture and in the making of transdermal drug delivery systems—of course, these are both non-edible and insoluble.

Additionally, PEO is a very expensive polymer that is ill suited to tobacco products from a cost perspective.

High levels of plasticizer are also not desirable for a number of reasons.

Plasticizer tends to increase the tackiness of a composition, potentially requiring the use of a substrate paper to separate the product when rolled up, and potentially further precluding a packaging configuration where one sheet rests on top of the other like in a cassette.

Additionally, relying on high levels of plasticizer tends to decrease the amount of active that can be loaded in the product.

Furthermore, reliance on plasticizer may create physical stability issues as the product will tend to increase in brittleness to the extend that the plasticizer volatizes during storage of the product.

Smokers are often reluctant to use these products because they are believed to be socially inappropriate since removal from the mouth can be embarrassing or can offend others.

Unlike the cast examples, it is noted this “tobacco film was placed in a container suitable for storage” presumably due to tackiness and other stability issues caused by exposure to ambient conditions.

It is highly doubtful that such fast dissolving products could deliver acceptable tobacco satisfaction, including sufficient nicotine absorption.

Undoubtedly, this is part of the reason why none of these products have been sold commercially.

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