US Patent 5,167,242: Scope, Claims, Expiration, and Nicotine Inhaler Patent Landscape

US Patent 5,167,242 covers a sealed, oxygen-protected nicotine cartridge and a cooperating inhalation system. Its central technical combination is a measured nicotine-loaded porous polymer reservoir, a nicotine- and oxygen-impermeable package, penetrable end barriers, inert-gas protection, and pressure-driven release into an inhaled air stream. The patent issued on December 1, 1992, and its enforceable term expired in 2009 under the pre-1995 patent-term rules. It does not create a current blocking right against generic nicotine inhalers or other nicotine-delivery products.

The patent remains commercially relevant because it describes the core architecture used in the Nicotrol inhaler concept, including a disposable cartridge, mouthpiece, sealed nicotine reservoir, and puncturable packaging. Its expired claims can still be used as prior art against later patent applications.

What does US Patent 5,167,242 cover?

US Patent 5,167,242, titled "Nicotine Inhaler," claims two related inventions:

A cartridge containing a measured amount of nicotine in a sealed, oxygen-free environment.
A nicotine delivery system that exposes the nicotine carrier to a pressure differential so nicotine vapor can be delivered to a user.

The patent focuses on product architecture and packaging rather than a particular clinical treatment regimen. Its strongest technical limitations are:

A nicotine reservoir positioned in an airflow passageway.
A measured nicotine quantity.
A reservoir capable of releasing nicotine vapor into an air stream.
A nicotine-impermeable barrier.
Passageway seals on both sides of the reservoir.
At least one penetrable barrier.
An inert-gas-filled region.
A pressure-driven delivery mechanism in the broader system claims.

The claims do not cover every nicotine inhaler. A competing product would need to satisfy the relevant structural and functional limitations of at least one claim.

What are the independent claims in US 5,167,242?

Claim 1: Sealed nicotine cartridge

Claim 1 is the principal cartridge claim. It requires:

Limitation	Scope
Cartridge housing	A physical housing containing the delivery components
Passageway	An internal channel with at least two external openings
Nicotine reservoir	Holds a measured amount of nicotine
Vapor release	Nicotine must be capable of entering a fluid stream
Sealed environment	Reservoir is sealed from the atmosphere
Oxygen protection	Barrier maintains an effectively oxygen-free environment
Penetrable passageway barrier	At least one seal can be opened by penetration
Inert-gas region	The space between the barrier portions is filled with inert gas

The claim is narrower than a general nicotine capsule claim. It requires both oxygen exclusion and an inert gas in the passageway region. A cartridge using ordinary air, vacuum, a liquid nicotine formulation, or a nonpenetrable opening mechanism may avoid one or more limitations.

Claim 14: Nicotine delivery system

Claim 14 is directed to a broader system concept. It requires:

A container effectively impermeable to nicotine and oxygen.
A carrier holding a measured amount of nicotine.
An oxygen-free environment.
Access means allowing the user to reach the interior.
Differential pressure means that releases nicotine vapor after access is provided.

Claim 14 does not expressly require a cartridge housing with two openings or a mouthpiece. Its language is more functional and potentially covers a wider range of pressure-assisted nicotine delivery configurations. The claim remains limited by the requirement for a sealed, oxygen-protected container and vapor release through an access mechanism.

How do the dependent claims narrow the patent scope?

Claims 2 through 13 narrow claim 1. Claims 15 through 23 narrow claim 14.

Cartridge and mouthpiece limitations

Claims 2 and 3 require an elongated housing, with claim 3 specifying a cylindrical form. Claim 4 adds a mouthpiece having:

An elongated passageway.
A user-facing opening.
A receiving section for the cartridge.
A sharpened peripheral end.
A structure that penetrates the cartridge barrier.

Claim 5 adds a molded plastic dispenser with cartridge compartments, a mouthpiece tray, and a sharpened tip. This claim reaches the combination of the consumable cartridge, mouthpiece, and storage dispenser rather than the cartridge alone.

Nicotine reservoir limitations

Claims 6 and 15 require a porous polymer plug charged with nicotine free base. Claims 7 and 16 further specify polyethylene.

This limitation is commercially significant. It excludes many modern delivery formats, including:

Nicotine salts in a liquid reservoir.
Aerosolized nicotine solutions.
Nicotine gum or lozenges.
Heated tobacco substrates.
Electronic-cigarette cartridges using a wick and e-liquid.
Solid nicotine matrices that are not porous polymer plugs.

Barrier and housing materials

Claims 8 and 19 require a copolymer of acrylonitrile and methyl acrylate. Claims 9, 10, 11, 12, 20, and 21 add aluminum foil and a heat-sealed acrylonitrile-methyl acrylate coating.

These claims protect a particular packaging solution intended to reduce nicotine permeation and oxygen ingress. The material limitations create substantial design-around flexibility. A later product using glass, multilayer polyethylene, fluoropolymer film, metallized laminate, or another barrier structure may avoid these dependent claims while potentially implicating broader claims.

Inert gas

Claims 13 and 23 specify nitrogen. Claims 1 and 14 do not limit the inert gas to nitrogen, so argon or another technically suitable inert gas could satisfy the broader language if the remaining limitations are met.

What is the patent expiration date for US 5,167,242?

US Patent 5,167,242 issued on December 1, 1992. Because the application was filed under the pre-June 8, 1995 patent-term regime, the patent generally received a 17-year term from issuance, subject to applicable statutory adjustments. Its ordinary expiration date was December 1, 2009.

Event	Date
US patent issued	December 1, 1992
Ordinary 17-year patent term	December 1, 2009
Current enforceable status	Expired
Current patent blocking risk	None from this patent alone

The expiration eliminates the patent's exclusionary right. It does not eliminate the patent's value as prior art or remove confidential manufacturing know-how that may have been developed around the patented product.

What is the Orange Book status of US 5,167,242?

The patent is associated with the early nicotine-inhaler product architecture that was commercialized in connection with the Nicotrol inhaler. FDA approval for the Nicotrol inhalation system was obtained under NDA 020714. The product was approved as a smoking-cessation nicotine replacement therapy, not as an electronic cigarette or general-purpose nicotine vaporizer.[FDA, 1998]

Because US 5,167,242 expired in 2009, it has no current exclusivity value in the Orange Book. Any historical Orange Book listing would be expired and could not support a current Paragraph IV litigation strategy.

Orange Book relevance is separate from patent ownership:

FDA approval concerns safety, efficacy, labeling, and manufacturing controls.
Orange Book listings identify patents associated with approved drug products.
Patent expiration determines whether the listed patent can block an ANDA applicant.
Regulatory discontinuation or commercial withdrawal does not revive an expired patent.

When did Nicotrol lose patent and regulatory exclusivity?

The product's principal patent protection under US 5,167,242 ended in 2009. FDA regulatory exclusivity, if applicable to the original NDA, would have ended substantially earlier than the patent term. The product therefore has no remaining market exclusivity based on this patent.

The product's regulatory pathway was an NDA for nicotine replacement therapy. A later applicant seeking approval for an equivalent product would generally evaluate:

The reference listed drug's current FDA status.
Whether an ANDA pathway remains available.
Whether the reference product is discontinued for safety or effectiveness reasons.
Pharmaceutical equivalence and bioequivalence requirements.
Device compatibility and human-factors requirements.
Manufacturing controls for nicotine content and permeation.
Any unexpired patents listed for the reference product.

What patent landscape surrounds nicotine inhalers?

The relevant landscape has four layers.

Early nicotine inhaler and vapor-delivery patents

Earlier patents generally addressed the concept of delivering nicotine through inhalation, volatilization, or an air stream. Their claims often differ from US 5,167,242 by focusing on:

A nicotine-containing plug or absorbent body.
Airflow over a nicotine source.
A heated or volatilized nicotine formulation.
A smoking-substitute device.
A mouthpiece or inhalation tube.

US 5,167,242 distinguishes itself through packaging and stability features. The oxygen-free environment, barrier seals, inert-gas fill, and penetrable cartridge construction are central differentiators.

Nicotine replacement therapy patents

Other patent families have focused on transdermal patches, gum, lozenges, nasal sprays, buccal tablets, and inhalation formulations. These patents tend to protect:

Release rates.
Adhesive matrices.
Taste masking.
Mucosal absorption.
Dose titration.
Combination therapy.
Specific salts or buffering systems.

They do not necessarily overlap with the cartridge claims in US 5,167,242 because they use different dosage forms and delivery mechanisms.

Electronic nicotine-delivery patents

Electronic cigarettes and heated nicotine devices use a different technical platform. Their patent claims commonly cover:

Liquid reservoirs.
Wicks and capillary structures.
Resistive heaters.
Aerosol-generation chambers.
Airflow sensors.
Rechargeable power systems.
Nicotine-salt formulations.

A conventional electronic cigarette generally does not satisfy claim 1 because it lacks the claimed porous polyethylene plug, penetrable end barriers, and inert-gas-filled passageway. It also may not satisfy claim 14 if the system does not use a sealed oxygen-free container with the claimed access and pressure-release arrangement.

Modern pharmaceutical inhaler patents

Modern inhaler patents often cover metered-dose valves, dry-powder formulations, blister packages, dose counters, and inhalation-actuated mechanisms. A dry-powder inhaler can share the concepts of metered dosing and inhaled airflow, but those similarities alone do not establish claim overlap. The specific nicotine reservoir, barrier, and vapor-release limitations remain important.

Which companies have commercial exposure to this patent?

The patent's commercial relevance is principally historical. The Nicotrol inhaler was associated with McNeil Consumer Pharmaceuticals and the nicotine replacement therapy business. The underlying technology was developed through academic and pharmaceutical commercialization channels, with patent ownership and product rights reflected in the patent record and product documentation.[USPTO, 1992; FDA, 1998]

Current commercial exposure is limited because:

The patent expired.
The patent cannot support an injunction against a current competitor.
No current royalty obligation can arise solely from the expired patent.
A new product may still require FDA authorization, even though it does not require a license under this patent.

Revenue exposure therefore relates to the discontinued or legacy product franchise, not to continuing patent exclusivity. Public company revenue attributable solely to this patent is not separately reported in standard financial disclosures.

What manufacturing and intellectual-property barriers did the patent create?

During its term, the patent could have raised barriers in four areas:

Nicotine stability

Nicotine is susceptible to oxidation and permeation through packaging materials. The claimed oxygen-free environment and barrier package addressed both problems. A manufacturer would need to control:

Oxygen ingress.
Nicotine migration.
Seal integrity.
Storage temperature.
Dose uniformity.
Long-term vapor release.

Material selection

The claimed use of acrylonitrile and methyl acrylate copolymers, aluminum foil, and heat sealing established a specific packaging solution. A competing manufacturer could design around the material claims, but would still need equivalent stability performance.

Dose control

The claims require a measured amount of nicotine. Manufacturing processes therefore must control reservoir loading, nicotine concentration, plug porosity, and unit-to-unit dose variation.

Device assembly

The cartridge and mouthpiece must cooperate mechanically. The sharpened mouthpiece or dispenser tip must penetrate the barrier without damaging the airflow path or compromising dose delivery. That creates manufacturing requirements around alignment, insertion force, seal geometry, and particulate control.

These barriers are now technical and regulatory rather than patent-based. They may remain relevant to product development even though the patent has expired.

How strong was the patent estate?

The estate was strongest against a product that copied the original architecture: a cylindrical disposable cartridge containing a nicotine-charged porous polyethylene plug, sealed with puncturable aluminum-foil barriers, nitrogen-filled, and inserted into a sharpened mouthpiece.

Its practical strengths were:

Multiple independent claim concepts.
Product and system coverage.
Stability and packaging limitations tied to nicotine's physical properties.
Dependent claims covering a coherent commercial embodiment.
Coverage of the cartridge, mouthpiece, and dispenser combination.

Its limitations were:

Narrow material claims.
Dependence on a porous polymer plug and nicotine free base.
Narrow penetrable-barrier architecture.
No current enforceability because the patent expired.
Limited relevance to liquid, salt-based, electronic, heated, or dry-powder nicotine systems.

The patent was commercially meaningful during its term but does not represent a current freedom-to-operate barrier for modern nicotine-delivery products.

What generic launch scenarios exist for the nicotine inhaler?

A generic or follow-on product could pursue several routes:

Product approach	Patent risk from US 5,167,242	Primary regulatory issue
Copy of original sealed nicotine cartridge	Historical overlap, no current patent block	ANDA or other FDA pathway
Liquid nicotine inhaler	Low claim overlap	Formulation, device, and dose equivalence
Electronic aerosol device	Generally low claim overlap	Combination-product and device requirements
Dry-powder nicotine inhaler	Limited overlap unless using the claimed reservoir	Inhalation bioequivalence and dose delivery
Nicotine nasal or buccal product	No meaningful overlap	Separate dosage-form requirements
Cartridge using a different barrier package	Potential design-around	Stability and extractables/leachables

A Paragraph IV certification against this patent would no longer create meaningful litigation exposure because the patent expired. Any current challenge would focus on other unexpired patents, regulatory eligibility, or product-specific exclusivity.

Does US 5,167,242 create biosimilar risk?

No. Biosimilar law does not apply to nicotine, which is a small-molecule active ingredient rather than a biologic. The relevant competitive pathways are:

ANDA approval for a pharmaceutically equivalent product.
505(b)(2) approval for a product relying partly on existing information but differing in formulation, device, or route.
A new NDA where the product has materially different characteristics.

The patent has no bearing on biosimilar interchangeability or the Biologics Price Competition and Innovation Act.

Key Takeaways

US Patent 5,167,242 covers a sealed nicotine inhaler cartridge and a pressure-assisted nicotine delivery system.
Claim 1 centers on a measured nicotine reservoir, oxygen-free packaging, penetrable seals, an airflow passageway, and inert gas.
Claim 14 provides broader system coverage for a sealed nicotine carrier opened to a pressure differential.
Dependent claims focus on porous polyethylene plugs, nicotine free base, acrylonitrile-methyl acrylate materials, aluminum foil, heat sealing, nitrogen, mouthpieces, and dispensers.
The patent issued December 1, 1992, and expired December 1, 2009.
It has no current Orange Book blocking power and cannot support a present Paragraph IV infringement action.
It does not cover modern nicotine products merely because they deliver nicotine by inhalation.
Its continuing value is as prior art and as a description of stability, packaging, and cartridge-engineering solutions.

FAQs

Can a company sell a nicotine inhaler without licensing US 5,167,242?

Yes. The patent expired in 2009, so a license is not required solely under US 5,167,242. Other unexpired patents, FDA requirements, trademarks, and confidential know-how may still affect commercialization.

Does a nitrogen-filled nicotine cartridge infringe the expired patent?

It cannot create present infringement liability under an expired patent. During the patent term, nitrogen alone would not have been enough. The product would also have needed to satisfy the applicable reservoir, passageway, barrier, oxygen-free, and access limitations.

Does US 5,167,242 cover nicotine e-cigarettes?

Generally, no. The claims are directed to a sealed cartridge or system using a measured nicotine carrier, penetrable barriers, and vapor release through a defined passageway. Typical e-cigarettes use liquid reservoirs, wicks, heaters, and electronic controls.

Is the Nicotrol inhaler still protected by market exclusivity?

No exclusivity remains under US 5,167,242. Any current market protection would have to arise from other patents, regulatory exclusivity, trademarks, manufacturing know-how, or commercial factors.

Could the patent be asserted against a dry-powder nicotine inhaler?

Not now, because the patent expired. During its term, a dry-powder product would generally avoid the claims if it lacked the claimed nicotine-loaded porous polymer plug, oxygen-free sealed container, penetrable barriers, and vapor-release structure.

References

U.S. Patent and Trademark Office. (1992). Nicotine inhaler (U.S. Patent No. 5,167,242). https://patents.google.com/patent/US5167242
U.S. Food and Drug Administration. (1998). Nicotrol inhaler: Prescribing information, NDA 020714. Drugs@FDA. https://www.accessdata.fda.gov/scripts/cder/daf/
U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations. Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
U.S. Patent and Trademark Office. (n.d.). Patent term adjustment and patent term provisions. https://www.uspto.gov/patents/laws/patent-term-calculator-selector

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	174805	⤷ Start Trial
Australia	642506	⤷ Start Trial
Australia	8002791	⤷ Start Trial
Brazil	9106537	⤷ Start Trial
Canada	2084771	⤷ Start Trial
China	1059649	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,167,242

Summary for Patent: 5,167,242