United States Patent 8,518,919: Azelastine Nasal Spray Claims, Scope, Expiration and Generic Risk

U.S. Patent No. 8,518,919 protects a specific azelastine hydrochloride nasal formulation and its use to treat allergic rhinitis or non-allergic vasomotor rhinitis. The patent is formulation- and method-of-use focused. It does not broadly cover azelastine, azelastine hydrochloride as an active ingredient, or every azelastine nasal product.

The core protected combination is:

Azelastine hydrochloride at approximately 0.10% to 0.15% w/v
Sucralose at approximately 0.10% to 0.15% w/v
Sorbitol 70% at approximately 0.1% to 10% w/v
Intranasal delivery as a spray or drops
Treatment of allergic rhinitis or non-allergic vasomotor rhinitis

The narrowest commercially important embodiment uses 0.100% azelastine hydrochloride, 0.150% sucralose, 6.4% sorbitol 70%, hypromellose, disodium edetate, benzalkonium chloride, sodium citrate dihydrate and water.

What does U.S. Patent 8,518,919 cover?

The patent covers a method of treating a patient with a liquid azelastine hydrochloride composition meeting defined concentration, excipient, disease and delivery limitations. Its claims are not directed primarily to the chemical compound itself.

Claim feature	Scope under the claims
Active ingredient	Azelastine hydrochloride
Azelastine concentration	About 0.10% to about 0.15% w/v in independent claim 1
Sweetener	Sucralose at about 0.10% to about 0.15% w/v
Osmolality agent	Sorbitol 70% at about 0.1% to about 10% w/v
Disease	Allergic rhinitis or non-allergic vasomotor rhinitis
Dosage form	Nasal spray or nasal drops
Patient	Animal; dependent claims narrow this to mammals and humans
Device	Bottle and pump; dependent claims specify a metered multi-dose pump
Spray volume	About 0.07 mL to about 0.15 mL per spray; claim 10 specifies about 0.14 mL
Additional excipients	Hypromellose, disodium edetate, benzalkonium chloride, sodium citrate dihydrate and water
Osmolality	About 220 to about 350 mOsmol/kg in claims 15 and 20

The patent therefore operates as a combination claim. A product must satisfy the relevant elements together. A composition containing azelastine hydrochloride alone, or azelastine with a different sweetener, does not inherently fall within claim 1.

How are the independent and dependent claims structured?

Claim 1 is the principal method claim. It requires four technical groups of limitations:

Administration to an animal suffering from or predisposed to a specified rhinitis disorder.
A liquid pharmaceutical composition.
Defined concentrations of azelastine hydrochloride, sucralose and sorbitol 70%.
Nasal spray or nasal-drop administration.

Claims 2 and 3 narrow the patient population from an animal to a mammal and then to a human.

Claims 4 and 5 separately identify nasal spray and nasal-drop formats. Claim 4 is commercially more significant because azelastine products are generally marketed as metered nasal sprays.

Claims 6 through 10 add device and dose-delivery limitations. They cover an intranasal delivery system, a bottle-and-pump configuration, a metered multi-dose pump and a defined spray volume.

Claims 11 through 14 address more specific compositions. Claim 11 is particularly narrow because it identifies a detailed formulation:

0.100% w/v azelastine hydrochloride
0.150% w/v sucralose
6.4% w/v sorbitol 70%
0.100% w/v hypromellose
0.05% w/v disodium edetate
0.025% w/v benzalkonium chloride 50% solution, NF
0.068% w/v sodium citrate dihydrate
Water quantity sufficient

Claim 14 covers the 0.150% azelastine embodiment and retains the excipient architecture, while allowing a broader sorbitol range.

Claims 15 and 20 introduce osmolality as a functional limitation. A formulation falling within the excipient concentration ranges but outside approximately 220 to 350 mOsmol/kg would not meet these claims.

What formulation is most commercially important?

The key formulation is the 0.15% azelastine hydrochloride nasal spray architecture associated with Astepro-type products. The patent also reaches a 0.10% azelastine composition through claim 11.

Formulation characteristic	Commercial relevance
0.10% azelastine hydrochloride	Associated with traditional azelastine nasal spray strengths
0.15% azelastine hydrochloride	Associated with Astepro-type nasal spray products
Sucralose	Taste-masking excipient
Sorbitol 70%	Sweetener and tonicity-adjusting agent
Hypromellose	Viscosity and formulation-performance excipient
Benzalkonium chloride	Preservative
Disodium edetate	Chelating agent
Sodium citrate	Buffering component
Metered pump	Supports reproducible intranasal dose delivery

The claims are drafted to capture both composition characteristics and the patient-use context. That structure can complicate design-around analysis because a competitor may avoid infringement either by changing the formulation or by eliminating a required use or delivery limitation.

What patents protect azelastine nasal products?

U.S. Patent 8,518,919 is one part of the broader azelastine patent landscape. The relevant patent categories are:

Patent category	Typical protected subject matter	Relevance to 8,518,919
Active-ingredient patents	Azelastine or azelastine hydrochloride chemistry	Generally separate from this patent
Formulation patents	Concentrations, excipients, pH, osmolality, viscosity and stability	Core category for 8,518,919
Device patents	Pumps, actuators, dose volume and spray plume	Potentially overlapping with claims 6-10
Method-of-use patents	Treatment of allergic rhinitis or vasomotor rhinitis	Directly relevant to claim 1
Manufacturing patents	Mixing, filling, preservation and scale-up processes	Not expressly required by the supplied claims
Combination-product patents	Azelastine with fluticasone or other active ingredients	Separate competitive estate

The patent does not claim every formulation containing hypromellose, sorbitol or benzalkonium chloride. Each claimed ingredient must be evaluated in combination with the concentration and disease-use limitations.

When does U.S. Patent 8,518,919 lose exclusivity?

The patent issued on August 27, 2013. Its nominal term is generally calculated from the earliest effective nonprovisional filing date, subject to patent-term adjustment, terminal disclaimers and any other USPTO term calculation. Public patent records associate the patent family with a nominal expiration in or around 2029, but the enforceable expiration date should be taken from the USPTO maintenance and patent-term records rather than inferred solely from the issue date (U.S. Patent and Trademark Office, 2013).

The patent term does not by itself determine when a generic can launch. A generic company must also consider:

FDA product-specific approval requirements
Listed patents for the relevant reference product
Paragraph IV certifications
Regulatory exclusivity
Court-imposed injunctions
Settlement restrictions
Whether the generic formulation practices the asserted claims

The patent’s expiration would remove this patent as a barrier, but it would not remove unrelated patents covering a reference product, delivery system or combination therapy.

What is the Orange Book status of U.S. Patent 8,518,919?

Orange Book relevance depends on whether the patent is listed against a specific FDA-approved drug product and whether the listing remains active. The patent number alone does not establish current Orange Book status.

For a listed patent, the principal regulatory consequences are:

An ANDA applicant must make a patent certification under 21 U.S.C. § 355(j)(2)(A)(vii).
A Paragraph IV certification alleges that the listed patent is invalid, unenforceable or will not be infringed.
The patent holder may sue within 45 days of receiving notice.
Timely patent litigation can trigger a statutory 30-month stay of approval, subject to statutory exceptions and court action (FDA, n.d.-a).

Because the claims are directed to a formulation and method of treatment, the patent would be most relevant if listed for an azelastine nasal spray reference product whose approved formulation and labeling correspond to the claimed composition and use. Orange Book listing status should be assessed by product, NDA, patent-use code and current listing status, not by patent number in isolation (FDA, n.d.-b).

What Paragraph IV challenges could target this patent?

A Paragraph IV challenge could attack the patent on several grounds:

Noninfringement

An ANDA formulation could avoid one or more mandatory limitations by:

Omitting sucralose
Using a different sweetener
Using sorbitol outside the claimed range
Using azelastine hydrochloride below 0.10% or above 0.15%
Using a different dosage form
Using a delivery volume outside the claimed spray range
Avoiding the claimed indication or method-of-use labeling
Using a formulation with osmolality outside the range in claims 15 and 20

The strength of a noninfringement position would depend on the ANDA’s formulation, product labeling and proposed commercial instructions.

Invalidity based on anticipation

An anticipation challenge would require a single prior-art reference to disclose every limitation of the asserted claim. For claim 1, the reference would need to disclose the active concentration, sucralose range, sorbitol range, liquid intranasal formulation and specified rhinitis treatment.

The detailed formulation claim 11 is harder to anticipate because it requires a specific collection of excipients and concentrations. A prior reference disclosing azelastine nasal spray generally would not anticipate claim 11 without the claimed formulation details.

Invalidity based on obviousness

An obviousness challenge could combine prior art relating to:

Azelastine nasal sprays
Sucralose for taste masking
Sorbitol for tonicity
Hypromellose for viscosity
Preservatives and chelating agents
Metered nasal pump delivery

The patent holder would likely rely on formulation performance, taste, stability, spray characteristics, tolerability or osmolality results to rebut an obviousness argument. The commercial importance of such data depends on what the patent specification and prosecution history show.

Written description and enablement

The broad ranges in claim 1 could be challenged if the specification does not adequately support the full combination of concentrations and excipients. Claims 11 and 14 are more technically specific and may have stronger written-description support if the patent reports those exact formulations.

How strong is the patent estate?

The patent has moderate blocking potential against products that closely copy the claimed formulation. Its strength is lower against products designed around the excipient combination or against products using a materially different azelastine formulation.

Risk factor	Assessment
Protection of azelastine molecule	Low under these claims
Protection of 0.10%-0.15% azelastine nasal formulations	High if sucralose and sorbitol ranges are also present
Protection of 0.15% azelastine products	Potentially high, depending on formulation overlap
Protection of alternative sweeteners	Limited
Protection of non-nasal dosage forms	None under the supplied claims
Protection of device configuration	Moderate, limited to dependent claim elements
Protection of manufacturing process	Not established by the supplied claims
Method-of-use exposure	Relevant where labeling includes covered rhinitis indications
Design-around potential	Material

The broadest commercially relevant risk lies in claim 1. The narrower claims can strengthen enforcement against an exact or near-exact copy but provide less coverage against technically modified products.

What generic launch risks exist?

The principal generic launch scenarios are:

Launch scenario	Patent exposure
Exact 0.15% azelastine formulation with sucralose and sorbitol	High potential exposure
0.15% azelastine with a different sweetener	Lower exposure, subject to other patents
Azelastine nasal spray without sucralose	Reduced exposure to claim 1
Azelastine nasal spray with sorbitol outside the claimed range	Reduced exposure, subject to claim construction
Product with different spray volume	May avoid claims 9 and 10, but not necessarily claim 1
Product labeled for a non-covered indication	May reduce method-of-use exposure
Product launched after patent expiration	No infringement risk from this patent

A formulation change can create regulatory and commercial costs. Taste, viscosity, preservative effectiveness, spray pattern, dose uniformity and patient acceptability may limit practical design-around options even where a legal design-around is available.

Does the patent create biosimilar risk?

No. Azelastine hydrochloride is a small-molecule drug. The relevant abbreviated pathway is generally an ANDA under section 505(j), not a biosimilar application under section 351(k). Biosimilar interchangeability, reference biologic exclusivity and biologic manufacturing comparability are not central issues for this patent.

The relevant competition is among:

Generic azelastine hydrochloride nasal sprays
Branded azelastine products
Azelastine-fluticasone combination products
Other intranasal antihistamines
Intranasal corticosteroids
Over-the-counter allergy products

What litigation and settlement issues affect the patent?

A complete litigation determination requires review of PACER, district-court dockets, Federal Circuit decisions, FDA patent correspondence and Orange Book records. The supplied claim text does not identify a particular Paragraph IV notice, defendant, settlement or injunction.

The principal litigation questions are:

Whether the patent was listed for the relevant azelastine reference product.
Whether an ANDA applicant filed a Paragraph IV certification.
Whether the patent holder filed suit within 45 days.
Whether the case produced a 30-month stay.
Whether the parties entered a license or agreed launch date.
Whether the patent survived claim construction and validity challenges.
Whether the asserted claims were limited by prosecution-history estoppel.

No licensing deal or settlement agreement can be attributed to U.S. Patent 8,518,919 solely from the patent and claims supplied.

How does this patent compare with competing azelastine estates?

The patent is narrower than a composition-of-matter patent but can be more commercially relevant for an approved nasal spray because it targets the finished dosage form.

Estate type	Breadth	Generic relevance
Azelastine composition-of-matter patent	Broad chemical protection	Usually historical or expired for older products
8,518,919 formulation/use patent	Medium to narrow	High for matching formulations
Pump or actuator patent	Narrow device coverage	Relevant to exact delivery systems
Azelastine-fluticasone combination patent	Combination-specific	Relevant to Dymista-type products
Manufacturing patent	Process-specific	Depends on ANDA manufacturing route

The main competitive distinction is between copying the branded formulation and entering with an alternative formulation. The patent has greater leverage over the first scenario than the second.

What geographic coverage does the patent provide?

U.S. Patent 8,518,919 provides rights in the United States only. Foreign protection would depend on corresponding national or regional family members. A U.S. patent does not block products manufactured, sold or used entirely outside the United States, although importation into the United States can create infringement issues under 35 U.S.C. § 271.

A global freedom-to-operate review would need separate analysis of:

European patent family members
Canadian patents
Japanese patents
Australian patents
Patent applications in other commercial markets
Local regulatory exclusivity
National claim scope and expiration dates

What manufacturing and intellectual-property barriers remain after expiration?

After expiration, the formulation patent would no longer block commercial manufacture based on its claims. Technical barriers may remain:

Preservative efficacy
Spray-dose uniformity
Container-closure compatibility
Pump reproducibility
Osmolality control
Azelastine stability
Microbial control
Taste and throat-drip tolerability
Scale-up consistency

These are development and regulatory barriers rather than continuing patent rights under the supplied claims. Separate patents covering pumps, manufacturing processes or combination products could remain relevant.

Key Takeaways

U.S. Patent 8,518,919 is a formulation and method-of-use patent, not a broad azelastine compound patent.
Claim 1 requires azelastine hydrochloride, sucralose, sorbitol 70%, intranasal delivery and treatment of specified rhinitis disorders.
Claims 11 and 14 protect more specific 0.10% and 0.15% formulations with hypromellose, disodium edetate, benzalkonium chloride, sodium citrate and water.
Claims 6 through 10 add bottle, pump, metered-dose and spray-volume limitations.
The nominal patent term runs into approximately 2029, subject to the official USPTO term calculation.
Generic exposure is highest for an exact or near-exact copy of the claimed 0.15% azelastine formulation.
A different sweetener, altered sorbitol range, changed spray volume or alternative formulation may reduce infringement risk.
Paragraph IV, Orange Book and settlement analysis must be performed against the specific reference product and current regulatory records.
Biosimilar law is not relevant because azelastine is a small molecule.
The patent is commercially meaningful but does not prevent all azelastine nasal spray competition.

FAQs About U.S. Patent 8,518,919

Does U.S. Patent 8,518,919 cover all azelastine nasal sprays?

No. It covers nasal formulations and treatment methods meeting the claimed ingredient, concentration, disease and delivery limitations.

Can a generic use azelastine with sucralose?

Potentially, but the product must be evaluated against the claimed sucralose and sorbitol ranges, azelastine concentration, dosage form and method-of-use limitations.

Does a 0.15% azelastine product automatically infringe?

No. The 0.15% azelastine concentration is only one limitation. Infringement depends on the complete formulation, delivery system and claimed use.

Is sorbitol 70% the same as ordinary sorbitol for infringement analysis?

The commercial grade and claim construction matter. A formulation using sorbitol must be assessed against the claim language, specification, prosecution history and product composition.

Can a company avoid the patent by changing the nasal pump?

Changing the pump may avoid device-specific dependent claims, but it may not avoid claim 1 if the formulation and covered treatment method remain unchanged.

Sources

Food and Drug Administration. (n.d.-a). Abbreviated new drug application (ANDA): Patent certifications and 30-month stay provisions. U.S. Department of Health and Human Services.
Food and Drug Administration. (n.d.-b). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. U.S. Department of Health and Human Services.
U.S. Patent and Trademark Office. (2013). U.S. Patent No. 8,518,919. U.S. Department of Commerce.
U.S. Congress. (2024). 35 U.S.C. § 271: Infringement of patent. United States Code.
U.S. Congress. (2024). 21 U.S.C. § 355: New drugs. United States Code.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2005309657	⤷ Start Trial
Australia	2012201428	⤷ Start Trial
Australia	2012203343	⤷ Start Trial
Brazil	PI0517891	⤷ Start Trial
Canada	2588338	⤷ Start Trial
China	101098714	⤷ Start Trial
Cyprus	1121330	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,518,919

Summary for Patent: 8,518,919