US Patent 6,413,499: Scope, Claims, Expiration, and Nasal Dental-Anesthesia Patent Landscape

US Patent 6,413,499 covers a method of anesthetizing portions of the maxillary dental arch by delivering a local anesthetic to the rear of the nasal cavity near nerves associated with the upper teeth, palate, or both. The claims also cover vasoconstrictors, aqueous formulations, nasal delivery devices, ancillary gingival anesthesia, nasal-drip control, and dental procedures performed after nasal administration.

The patent is a foundational method patent for nasal dental anesthesia, but it is no longer an enforceable exclusionary right. Based on the patent’s filing chronology and the 20-year US patent term, its ordinary term expired around 2019, subject to any applicable patent-term adjustment. The patent therefore has historical and freedom-to-operate significance, but it does not currently block generic nasal anesthetic products or competing delivery systems.

What invention does US Patent 6,413,499 protect?

The patent protects a route-of-administration concept: using the posterior nasal cavity as the delivery site for anesthetizing the maxillary dental arch.

The core mechanism claimed is:

A pharmaceutically effective local anesthetic is provided.
The composition is delivered to the rear of the nasal cavity.
Nasal tissue near nerves serving the maxillary teeth or palate absorbs the anesthetic.
The anesthetic produces selective, remote anesthesia of the upper teeth, hard palate, soft palate, or related structures.

The claims are method claims rather than composition-of-matter claims. They do not broadly claim tetracaine, lidocaine, oxymetazoline, or other anesthetic ingredients as chemical substances. They claim their use in a specific nasal-dental anesthesia method.

How broad is independent claim 1?

Claim 1 is the principal broad claim. It requires:

Claim element	Scope
Patient anatomy	At least part of the maxillary dental arch
Product form	A nasally deliverable anesthetizing composition
Active ingredient	A pharmaceutically effective amount of an anesthetizing agent
Route	Delivery into the rear of the nasal cavity
Target tissue	Nasal tissue near at least one nerve associated with maxillary dental pain
Result	Selective and remote anesthesia of at least part of the maxillary dental arch

The claim does not require:

A particular anesthetic molecule
A particular concentration
A particular spray device
A vasoconstrictor
A specific dental procedure
An aqueous formulation
An FDA-approved product
An explicit limitation to tetracaine or lidocaine
A quantified delivery volume

The principal limitation is functional and anatomical: delivery must occur in the rear of the nasal cavity in the vicinity of nerves responsible for pain transmission from the maxillary dental arch. A product used only as a general nasal anesthetic, without the claimed dental-anesthesia purpose and delivery targeting, would not necessarily satisfy the claim.

What dependent claims add to the patent scope?

Claims 2 and 3: Upper teeth and alveolar nerves

Claims 2 and 3 narrow the method to anesthesia of one or more teeth in one maxillary hemisphere. They identify the anterior superior alveolar, middle superior alveolar, and posterior alveolar nerves, along with related nerves.

These claims create a dental-nerve targeting limitation. The claims do not require that a clinician directly inject or physically contact the named nerve. The method can be practiced through nasal absorption if the claimed anesthetic effect is achieved.

Claims 4 and 5: Palatal anesthesia

Claim 4 covers anesthesia of at least part of the hard palate through targeting of the greater palatine nerve or related nerves.

Claim 5 covers anesthesia of at least part of the soft palate through targeting of the lesser palatine nerve or related nerves.

These claims extend the patent beyond tooth anesthesia. A nasal product used to anesthetize the palate could fall within these claims if the other claim elements are satisfied.

Claim 6: Local-anesthetic genus

Claim 6 identifies a broad list of anesthetic agents:

Tetracaine
Lidocaine
Benzocaine
Dyclonine
Pramoxine
Dibucaine
Butacaine
Cocaine
Salts of those agents
Analogues of those agents

Because claim 6 depends on claim 1, it does not independently claim these compounds in all uses. It covers their use in the claimed posterior-nasal, maxillary-dental anesthesia method.

The inclusion of salts and analogues expands the chemical scope, although an asserted analogue would still need to satisfy the claim language and ordinary principles of claim construction. The claim does not expressly include every modern local anesthetic, such as articaine or mepivacaine, unless a particular product is treated as an analogue under the claim.

Claims 7 through 11: Vasoconstrictors

Claims 7 through 11 cover the use of a vasoconstrictor to promote nasal absorption and limit migration of the anesthetic away from the target nerve.

The listed vasoconstrictors include:

Oxymetazoline hydrochloride
Phenylephrine hydrochloride
Naphazoline hydrochloride
Propylhexedrine
Levodesoxyephedrine
Analogues of those agents

The claims permit the vasoconstrictor to be:

Included in the anesthetic composition
Administered separately
Administered before, during, or after the anesthetic
Used to promote absorption
Used to inhibit unwanted migration

Claims 7 through 11 are particularly relevant to products combining a local anesthetic with oxymetazoline. A commercial product using tetracaine and oxymetazoline would fall within the technical subject matter described by these claims, although the expired status of the patent prevents current enforcement of those claims.

Claim 12: Formulation excipients

Claim 12 covers inert ingredients used to modify:

Wetting
Viscosity
pH
Dilution

This claim reaches formulation design features without specifying particular excipients. It could historically have covered nasal sprays, gels, suspensions, or other formulations using excipients selected to control residence time and nasal absorption.

Claim 13: Dosage forms

Claim 13 identifies the composition as one or more of:

Liquid
Solution
Suspension
Gel
Powder

The claim is drafted broadly enough to encompass several nasal dosage forms. It does not require a metered pump, aerosol propellant, single-dose container, or any other specific device architecture.

Claim 14: Posterior-nasal delivery device

Claim 14 covers a delivery device configured to preferentially deliver a desired dose to the rear of the nasal cavity.

This claim is important because it moves beyond the formulation and claims device-assisted targeting. A standard nasal spray may be evaluated under this claim if its configuration and use preferentially direct the composition toward the claimed posterior region.

Claims 15 through 18: Ancillary treatment steps

Claim 15 adds topical gingival anesthetic.

Claim 16 adds a nasal-drip inhibiting agent.

Claim 17 requires water to be present before delivery.

Claim 18 adds a dental procedure that would otherwise cause pain or discomfort, including procedures covered more specifically in claim 32.

These claims are narrower than claim 1 because infringement requires the additional step or formulation condition.

How do claims 19 through 24 differ from claim 1?

Claim 19 creates a second independent method with four required components:

Delivery of an anesthetic to the rear of the nasal cavity
Absorption near a nerve associated with maxillary dental pain
Provision of a vasoconstrictor
Use of the vasoconstrictor to promote absorption and inhibit migration

Claims 20, 21, and 22 address the timing of vasoconstrictor administration:

Claim	Timing
20	Before the anesthetic
21	At the same time as the anesthetic
22	After the anesthetic

Claims 23 and 24 add water and a painful dental procedure.

Claim 19 is narrower than claim 1 because a vasoconstrictor is mandatory. In exchange, it provides a more specific claim directed to the combination of posterior nasal delivery and vasoconstriction.

What do claims 25 through 32 protect?

Claim 25 is the third independent claim. It requires:

A nasally deliverable aqueous anesthetic composition
Delivery to the rear of the nasal cavity
Absorption near a nerve serving the maxillary dental arch
Performance of a dental procedure after anesthesia

Compared with claim 1, claim 25 adds two significant restrictions:

The anesthetic composition must be aqueous.
A dental procedure must be performed.

Claims 26 and 27 address the superior alveolar, greater palatine, and lesser palatine nerves.

Claim 28 repeats the listed anesthetic-agent class.

Claim 29 adds a vasoconstrictor.

Claim 30 requires that at least part of the vasoconstrictor be included in the anesthetic composition.

Claim 31 addresses a posterior-targeting delivery device.

Claim 32 identifies covered dental procedures, including:

Cavity drilling
Root canal procedures
Tooth extraction
Crown work
Bridge work

Claim 25 is commercially relevant because a product used in an actual dental procedure would more readily satisfy its treatment-step limitation than a product sold only for general nasal anesthesia.

What is the patent’s legal status and expiration timeline?

Item	Data
Patent	US 6,413,499
Patent type	Utility patent
Claim category	Method of treatment and administration
Issue date	July 2, 2002
Original term framework	20 years from the earliest effective nonprovisional filing date
Expected ordinary expiration	Approximately 2019, based on the patent’s filing chronology
Current enforceability	Expired; no prospective exclusionary patent right
Orange Book relevance	The patent is not a current blocking Orange Book patent for KOVANAZE

Under 35 U.S.C. § 154, a US utility patent generally expires 20 years after the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and certain prosecution delays. Patent 6,413,499 issued in 2002, but its term was not measured from the issue date. The ordinary term therefore ended well before the 2020s.

Expiration eliminates the right to prevent future practice of the claimed methods. It does not erase the patent’s historical relevance, affect ownership of earlier infringement claims that were timely preserved, or invalidate later patents that independently claim improved products, formulations, devices, or methods.

Is US Patent 6,413,499 listed in the Orange Book?

No current Orange Book exclusivity should be attributed to US 6,413,499.

The FDA’s Orange Book listing for KOVANAZE is associated with later patents and regulatory exclusivity, not with this expired foundational patent. KOVANAZE is a prescription nasal spray containing tetracaine hydrochloride and oxymetazoline hydrochloride and was approved by the FDA for regional anesthesia when a needle-free option is desired for certain dental procedures (FDA, 2016).

An expired foundational method patent can describe the same technical concept as an approved product without creating current Orange Book protection. Orange Book listing depends on the approved drug, the NDA holder’s patent certification submissions, and FDA listing rules under the Hatch-Waxman framework.

What FDA product is most closely associated with this patent technology?

The principal commercial product associated with this technology is KOVANAZE, also known as tetracaine hydrochloride and oxymetazoline hydrochloride nasal spray.

Product	Active ingredients	Route	Dental use
KOVANAZE	Tetracaine HCl and oxymetazoline HCl	Intranasal spray	Regional anesthesia for maxillary dental procedures

KOVANAZE reflects the same general technical architecture described by the patent:

Local anesthetic delivered intranasally
Posterior nasal targeting
Vasoconstrictor co-administration
Use in upper-jaw dental procedures

The product’s commercial protection depends primarily on later patents, regulatory exclusivity, manufacturing controls, clinical data, and market access rather than on US 6,413,499.

What later patents protect KOVANAZE and related nasal dental-anesthesia products?

Later patent families associated with intranasal dental anesthesia generally focus on narrower commercial features, including:

Specific tetracaine and oxymetazoline concentrations
Nasal spray formulations
Device geometry
Metered-dose delivery
Product stability
Treatment protocols
Specific dental indications
Manufacturing and packaging

Publicly identified KOVANAZE-related US patents include later patents such as US 8,865,688 and US 9,205,082. Other later patents have also been associated with the product and its formulation or delivery platform. The legal significance of each patent depends on its claims, terminal disclaimers, patent-term adjustments, maintenance status, and any later expiration or litigation developments.

The later patents are distinct from US 6,413,499. They do not become invalid merely because the earlier patent expired. Their validity depends on novelty, nonobviousness, written description, enablement, prosecution history, and the scope of their issued claims.

How strong was the patent estate for nasal dental anesthesia?

The original patent had meaningful breadth in three respects:

It claimed the treatment route rather than one narrow molecule.
It covered multiple anesthetics and vasoconstrictors.
It covered teeth, hard palate, soft palate, formulations, delivery devices, and dental procedures.

Its main weaknesses were also structural:

The claims depended on functional dental-anesthesia results.
The rear-of-nasal-cavity limitation could create factual disputes over delivery location.
The claims did not provide broad composition-of-matter protection.
Generic nasal anesthetics might avoid the claims if not marketed or used for maxillary dental anesthesia.
The patent had no current term after expiration.
Later products could be protected by narrower patents directed to specific combinations or formulations.

At the time of enforceability, claim 1 was the strongest commercial claim because it did not require a vasoconstrictor, water, a specific formulation, a particular device, or a named anesthetic. Claims 19 and 25 were narrower but more closely aligned with an integrated commercial product.

What generic entry risks exist after expiration?

The expiration of US 6,413,499 removes the central method patent as a barrier to entry, but a competitor still must evaluate later patents.

Potential entry pathways include:

Entry pathway	Principal risk
Tetracaine-only nasal product	Later formulation, delivery, or method patents
Tetracaine plus oxymetazoline	Later combination and concentration patents
Alternative anesthetic	Separate formulation and clinical-development requirements
Powder or gel	Device, residence-time, and formulation patents
Generic nasal spray	FDA approval pathway and product equivalence
Compounded product	State pharmacy rules, quality controls, and clinical liability
Dental-office device	Device patents and regulatory classification

A generic drug applicant seeking approval for a listed drug would evaluate patent certifications under 21 U.S.C. § 355(j), including Paragraph I, II, III, or IV certifications as applicable. A Paragraph IV certification can trigger patent litigation and a 30-month stay if the NDA holder or patent owner files suit within the statutory period.

Because US 6,413,499 is expired, it would not ordinarily support a current Paragraph IV challenge or a 30-month stay. Any present challenge would concern unexpired later patents listed for the approved product.

Which companies are relevant to the competitive landscape?

The market has historically centered on the sponsor and commercial ecosystem for KOVANAZE, including St. Renatus and related commercial partners. Competitive alternatives include:

Conventional injectable dental anesthetics
Topical oral anesthetics
Needle-free dental anesthesia systems
Compounded intranasal anesthetics
Other local-anesthetic delivery technologies
Dental devices designed to reduce injection pain

Conventional injectable products remain the principal substitute because they provide established efficacy across a wider range of dental procedures and anatomical targets. Intranasal anesthesia is more limited by anatomy, dose delivery, patient variability, and the scope of procedures for which adequate anesthesia can be achieved.

What litigation and settlement issues affect this patent?

The claims supplied do not establish a current litigation position, settlement agreement, or enforceable controversy. The patent’s expiration substantially reduces its present litigation value.

The legally material distinctions are:

Historical infringement claims may remain relevant only for conduct within the applicable limitations period.
Post-expiration commercial use is not blocked by the patent.
Later patents can be asserted independently.
A settlement involving later patents would not revive US 6,413,499.
A license to the expired patent would generally have limited present exclusionary value unless bundled with know-how, trademarks, regulatory assets, or later patent rights.

No current business strategy should treat US 6,413,499 alone as an injunction risk.

What geographic coverage did the patent provide?

The patent provided rights only in the United States. It did not directly block practice in:

Canada
Europe
Japan
China
Australia
Other jurisdictions

Foreign counterparts, if filed, would require separate analysis of filing dates, national-phase status, prosecution outcomes, maintenance fees, and expiration. US patent expiration has no automatic legal effect on foreign counterpart rights.

For a global launch, the relevant asset is the complete patent family, not the US patent in isolation. The strongest residual barriers may now exist in later US or foreign patents covering formulation, device construction, manufacturing, or approved-use protocols.

What manufacturing and intellectual-property barriers remain?

The expired patent does not eliminate non-patent barriers. A commercial nasal dental-anesthesia product may still require:

FDA approval
Clinical evidence of dental anesthesia
Dose uniformity validation
Nasal tolerability data
Stability testing
Container-closure qualification
Spray-pattern and plume testing
Good Manufacturing Practice compliance
Controlled handling of active ingredients
Pharmacovigilance and labeling controls

Manufacturing know-how may include mixing order, pH adjustment, preservative selection, filling parameters, spray-pump calibration, and packaging conditions. These trade secrets can remain valuable after patent expiration if they are not publicly disclosed and are subject to reasonable confidentiality controls.

How does US Patent 6,413,499 compare with later KOVANAZE patents?

Issue	US 6,413,499	Later KOVANAZE-related patents
Primary focus	Nasal dental-anesthesia concept	Specific product, formulation, device, or regimen
Claim type	Broad method claims	Often narrower product or method claims
Anesthetic scope	Multiple agents and analogues	More specific active ingredients or concentrations
Vasoconstrictor	Broad list, including oxymetazoline	Often tied to defined formulation or dose
Dental use	Maxillary teeth and palate	Defined approved indications or protocols
Current term	Expired	Depends on each patent’s expiration
Orange Book value	No current blocking value	Potentially relevant if currently listed
Generic risk	No current barrier	Depends on remaining claims and certifications
Commercial value	Historical platform right	Potentially active product protection

Key Takeaways

US Patent 6,413,499 claims posterior nasal delivery of local anesthetics to produce selective anesthesia of the maxillary dental arch and palate.
Claim 1 is the broadest claim and does not require a specific anesthetic, vasoconstrictor, formulation, device, or dental procedure.
Claims 19 and 25 add vasoconstrictor and aqueous-composition requirements, respectively.
The patent covers tetracaine, lidocaine, benzocaine, and several other anesthetics, along with oxymetazoline and other vasoconstrictors.
The patent is expired under the ordinary 20-year US patent-term framework and is not a current blocking right.
KOVANAZE reflects the patent’s technical concept but relies on later patent protection, FDA approval, manufacturing controls, and commercial assets.
Current generic or competing-product risk depends on later unexpired patents, not on US 6,413,499.
The patent has US-only territorial effect; foreign rights require separate family-level analysis.
The main residual barriers are later formulation and device patents, FDA approval requirements, manufacturing know-how, and clinical validation.

FAQs

Does US Patent 6,413,499 cover KOVANAZE?

It covers the general technical method reflected by KOVANAZE, including posterior nasal delivery of a local anesthetic for maxillary dental anesthesia and the use of a vasoconstrictor. It is not the current blocking patent for KOVANAZE because the patent has expired.

Can a company sell a nasal tetracaine product after this patent expired?

Expiration removes the exclusionary effect of this patent. The company must still evaluate later patents, FDA approval requirements, formulation claims, device claims, and manufacturing rights.

Does claim 6 cover articaine?

Claim 6 expressly lists tetracaine, lidocaine, benzocaine, dyclonine, pramoxine, dibucaine, butacaine, cocaine, their salts, and analogues. Articaine is not expressly named. Whether it falls within “analogues” would depend on claim construction and the technical and prosecution history.

Could a nasal spray avoid infringement by delivering to the front of the nose?

Potentially. The independent claims require delivery into the rear of the nasal cavity near nerves associated with the maxillary dental arch. A product and method limited to anterior nasal delivery could avoid that limitation, although actual use, device performance, and claim construction would control.

Are patents covering nasal dental anesthesia eligible for Paragraph IV challenges?

Yes, if they are unexpired patents properly listed for an approved drug and a generic applicant makes the required certification. US 6,413,499 itself is expired and would not ordinarily support a current Paragraph IV challenge or a 30-month stay.

References

Food and Drug Administration. (2016). KOVANAZE prescribing information. U.S. Department of Health and Human Services.
United States Congress. (2024). 35 U.S.C. § 154: Contents and term of patents; provisional rights.
United States Congress. (2024). 21 U.S.C. § 355: New drugs.
United States Patent and Trademark Office. (2002). U.S. Patent No. 6,413,499: Nasal administration of anesthetic agents for dental procedures.
United States Patent and Trademark Office. (2024). Patent term adjustment and patent term calculation guidance.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. Center for Drug Evaluation and Research.

Details for Patent: 6,413,499

Summary for Patent: 6,413,499