United States Patent 4,767,612: Scope, Claims, Expiration, and Triamcinolone Acetonide Nasal Spray Patent Landscape

U.S. Patent No. 4,767,612 covers a propellant-based nasal aerosol containing micronized triamcinolone acetonide for treating allergic rhinitis. The patent issued on August 30, 1988, and its enforceable term has expired. The core claims require a specific CFC aerosol formulation, not a modern aqueous pump spray. The patent therefore has historical relevance to Nasacort aerosol products but does not currently block generic or OTC aqueous triamcinolone acetonide nasal sprays.

What does U.S. Patent 4,767,612 cover?

U.S. Patent 4,767,612 covers a method of treating allergic rhinitis by administering a nasal aerosol containing:

Micronized triamcinolone acetonide;
Anhydrous ethanol;
Dichlorodifluoromethane, also known as CFC-12; and
An optional amount of sorbitan trioleate.

The patent is directed to both the formulation and its therapeutic use. It does not claim triamcinolone acetonide generally, all nasal formulations, or all methods of treating rhinitis.

The central formulation is a pressurized aerosol rather than a manually actuated aqueous pump spray. That distinction is important because modern triamcinolone acetonide products generally use aqueous suspension technology and do not contain dichlorodifluoromethane.

Core bibliographic information

Item	Information
Patent	U.S. Patent No. 4,767,612
Title	Triamcinolone acetonide nasal aerosol
Filing period	Pre-1995 U.S. patent application
Issue date	August 30, 1988
Technology	Pressurized nasal aerosol
Active ingredient	Micronized triamcinolone acetonide
Propellant	Dichlorodifluoromethane, CFC-12
Therapeutic field	Allergic rhinitis
Patent status	Expired
Current blocking effect	None, because the patent term has ended

The patent document identifies the claimed formulation and administration method. The claims should be read together with the specification, prosecution history, and applicable pre-1995 patent-term rules when assessing historical infringement exposure (U.S. Patent No. 4,767,612, 1988).

What are the claims of U.S. Patent 4,767,612?

Claim 1: Formulation and method claim

Claim 1 requires a method for controlling or treating allergic rhinitis in a patient with symptoms including rhinorrhea, nasal itching, sneezing, congestion, and postnasal drip.

The method requires administration into the nasal cavity of a nasal spray from an aerosol dispenser. The spray must consist essentially, by weight, of:

Component	Claimed amount
Micronized triamcinolone acetonide	3.75 to 30.0 mg
Anhydrous ethanol	123.75 to 97.5 mg
Dichlorodifluoromethane	9.75 g
Sorbitan trioleate	0 to 10 mg

The ethanol range is written in descending order in the claim, but the substantive range is 97.5 to 123.75 mg.

Claim 1 has several limiting elements:

The patient must have allergic rhinitis.
The method must address the specified nasal symptoms.
The product must be delivered into the nasal cavity.
Delivery must occur through a nasal spray from an aerosol dispenser.
The active ingredient must be micronized triamcinolone acetonide.
The formulation must contain the specified amounts of ethanol and CFC-12.
Sorbitan trioleate may be absent or present up to 10 mg.
The composition must meet the “consisting essentially of” transition.

Claim 2: Daily-dose limitation

Claim 2 depends on claim 1 and narrows the method by requiring a daily dose of 200 to 1,600 micrograms of micronized triamcinolone acetonide.

Claim 2 therefore includes every limitation of claim 1 plus the daily-dose limitation. It is narrower than claim 1 but remains tied to the same CFC-based aerosol platform.

How should the phrase “consisting essentially of” be interpreted?

“Consisting essentially of” is broader than “consisting of” but narrower than “comprising.” It generally permits additional ingredients that do not materially alter the basic and novel characteristics of the claimed composition.

For this patent, the basic characteristics likely include:

Delivery of micronized triamcinolone acetonide as a nasal aerosol;
Dispersion of the active ingredient in ethanol;
Use of dichlorodifluoromethane as the propellant; and
Therapeutic treatment of allergic rhinitis.

An additional excipient would not automatically avoid the claim. The relevant question would be whether the added ingredient materially changes the formulation’s identity, performance, delivery mechanism, or therapeutic characteristics.

A formulation using a materially different propellant, such as a hydrofluoroalkane, would present a stronger non-infringement position because CFC-12 is expressly required. A formulation that removes the propellant and uses a manually actuated aqueous pump would be even further removed from the claim.

What formulation characteristics are required?

The patent is unusually specific about the delivery system and excipient environment.

Micronized triamcinolone acetonide

The active ingredient must be micronized. Micronization is relevant to suspension stability, particle distribution, aerosolization, and deposition in the nasal cavity. A formulation containing non-micronized active ingredient would raise a claim-construction and literal-infringement issue, although equivalence theories could have been considered during the patent’s enforceable term.

Anhydrous ethanol

Claim 1 requires anhydrous ethanol within the specified weight range. This limitation distinguishes the claimed product from aqueous suspensions and from formulations using different cosolvents.

Dichlorodifluoromethane

Dichlorodifluoromethane, or CFC-12, is a required propellant. The presence of CFC-12 is central to the historical formulation but is commercially and regulatorily significant because CFC propellants were phased out in medical products under the Montreal Protocol and U.S. ozone-protection regulations.

Sorbitan trioleate

Sorbitan trioleate is optional. The claimed range of zero to 10 mg means that the claim covers formulations without sorbitan trioleate as well as formulations containing it within the stated limit.

What dose range does the patent protect?

Claim 2 covers a daily dose of 200 to 1,600 micrograms of micronized triamcinolone acetonide.

The dose range is broad relative to modern low-dose nasal products. It covers:

A 200-microgram daily dose;
Intermediate daily doses; and
A 1,600-microgram daily dose.

Because claim 2 depends on claim 1, the dose alone does not create infringement. A product must also use the claimed CFC aerosol composition and administration method.

A modern nasal spray delivering 55 micrograms per spray could fall within the general therapeutic field but would not necessarily fall within claim 2 unless the total daily dose reaches at least 200 micrograms and the product satisfies the formulation and aerosol limitations.

When did U.S. Patent 4,767,612 expire?

The patent expired in 2005.

For a pre-1995 U.S. application, the applicable patent term generally depended on the longer of 17 years from issuance or 20 years from the relevant filing date, subject to statutory exceptions and terminal disclaimers. U.S. Patent 4,767,612 issued on August 30, 1988. Its ordinary 17-year term therefore ended on August 30, 2005, absent an earlier terminal disclaimer or other limiting event.

Event	Date
Patent issue	August 30, 1988
Ordinary 17-year expiration	August 30, 2005
Current enforceability	None
Current generic blocking risk	None

The expired status means that the claims cannot support a new patent infringement action for current conduct. The patent can remain relevant to historical freedom-to-operate reviews, validity analysis, prosecution history, and the development of later patent families.

What was the relationship to Nasacort?

The patent is associated with the historical triamcinolone acetonide nasal aerosol technology used in the Nasacort product line. Nasacort later became associated with aqueous nasal spray products, including Nasacort AQ and the OTC Nasacort Allergy 24HR product.

The product evolution matters:

Product technology	Key characteristics	Relationship to Patent 4,767,612
Historical Nasacort aerosol	Pressurized CFC aerosol, ethanol-containing formulation	Closely aligned with patent claims
Nasacort AQ	Aqueous nasal suspension delivered by pump	Technically different from claimed CFC aerosol
Nasacort Allergy 24HR	OTC triamcinolone acetonide nasal spray	Modern aqueous pump-spray platform, not the claimed CFC formulation

The patent’s CFC limitation became commercially restrictive after the FDA prohibited continued use of CFC propellants in most nasal inhalation products under the phaseout of ozone-depleting substances. The modern products rely on a different delivery system and do not depend on the expired patent.

What is the FDA regulatory status of the relevant products?

Triamcinolone acetonide nasal products have been marketed through both prescription and OTC pathways. The historical aerosol technology was a prescription-era product platform. Later products moved to aqueous suspension technology and, for Nasacort Allergy 24HR, to OTC status.

The FDA’s regulatory framework separates:

The active ingredient;
The dosage form;
The route of administration;
The formulation;
The product-specific NDA or abbreviated application; and
The labeling and exclusivity history.

FDA approval of a triamcinolone acetonide nasal spray does not itself establish infringement of Patent 4,767,612. The formulation and delivery system must be compared against the claim limitations.

The Orange Book historically provided the relevant patent and exclusivity information for approved prescription products. Because Patent 4,767,612 expired in 2005, it no longer creates an Orange Book-based regulatory obstacle to approval of a competing product. Current OTC products are not blocked by an expired patent.

What was the Orange Book status of Patent 4,767,612?

The patent was relevant to the historical prescription product landscape, but it is no longer an operative Orange Book barrier.

An Orange Book patent listing can affect an ANDA applicant through:

A Paragraph IV certification;
A 30-month stay triggered by timely patent litigation;
A potential 180-day first-filer exclusivity period; and
Patent litigation or settlement negotiations.

Those mechanisms no longer provide practical leverage for Patent 4,767,612 because the patent has expired. A current ANDA applicant would not face a viable 30-month stay based on an expired patent.

The Orange Book status of any later triamcinolone acetonide product must be evaluated separately. Later patents could cover aqueous suspensions, delivery devices, preservatives, particle size, dosing regimens, or OTC formulations, but those claims would not revive the expired rights under Patent 4,767,612.

Were there Paragraph IV challenges to this patent?

A Paragraph IV certification would have been the relevant ANDA pathway if the patent was listed for an approved prescription product while still in force. Such a certification would assert that the patent was invalid, unenforceable, or not infringed.

The available claim structure presents several potential historical design-around and invalidity issues:

A formulation could replace CFC-12 with another propellant.
A product could use an aqueous pump spray.
A product could omit ethanol.
A product could use a different active-particle format.
A product could challenge the scope or validity of the claimed formulation and method.
A product could argue that its labeled dose or administration method did not meet claim 2.

Because the patent expired in 2005, any Paragraph IV dispute specific to this patent is now legally moot for future launches. A current competitor would ordinarily focus on later unexpired patents, regulatory requirements, and product-specific exclusivity.

What patent litigation affects U.S. Patent 4,767,612?

Patent 4,767,612 does not currently present an active litigation risk. Its enforceable term ended nearly two decades ago.

Historical litigation exposure would have depended on:

Whether the patent was listed for the relevant approved product;
Whether an ANDA applicant filed a Paragraph IV certification;
Whether the patent holder sued within the statutory period;
Whether a court issued a preliminary injunction or final judgment;
Whether the parties entered a settlement; and
Whether later patents supplied an independent basis for litigation.

The expired patent should therefore be classified as a historical patent asset rather than an active litigation asset. Any settlement involving the product would need to be reviewed separately to determine whether it addressed only Patent 4,767,612 or also later patents, regulatory exclusivity, or commercial launch terms.

How strong was the patent estate?

Strengths during the enforceable term

The patent had meaningful historical value because it combined:

A specific nasal route;
A defined therapeutic indication;
A pressurized aerosol dispenser;
Micronized triamcinolone acetonide;
A defined ethanol range;
CFC-12 as propellant; and
A dose-dependent dependent claim.

The “consisting essentially of” language also gave the composition claim some flexibility regarding non-material excipients.

Weaknesses during the enforceable term

The claim scope was limited by the CFC aerosol platform. That limitation reduced the patent’s usefulness as products moved toward non-CFC delivery systems.

Other constraints included:

The required propellant;
The required ethanol range;
The narrow formulation architecture;
The need to prove the claimed dose for claim 2;
The method-of-treatment structure; and
The potential availability of noninfringing aqueous or alternative-propellant designs.

Current strength

The current patent strength is zero as an enforceable right because the patent has expired. Its remaining commercial value is limited to historical know-how, prior-art analysis, and understanding of the transition from CFC aerosols to aqueous nasal sprays.

Does the patent create biosimilar risk?

No. Triamcinolone acetonide is a small-molecule corticosteroid, not a biologic. The relevant regulatory competition involves generic drugs, authorized OTC products, and formulation-specific nasal sprays, not biosimilars.

The principal competitive issues are:

ANDA approval for prescription products;
OTC monograph or NDA-based marketing;
Formulation equivalence;
Device performance;
Dose delivery;
Labeling; and
Later unexpired formulation or device patents.

What generic launch scenarios existed?

During the patent’s term, a competitor could have pursued several routes:

Launch route	Patent exposure
Identical CFC aerosol	High exposure during patent term
Alternative-propellant aerosol	Potential noninfringement, subject to claim construction
Aqueous pump spray	Stronger design-around position
Different ethanol system	Potentially outside literal claim scope
Different corticosteroid	Outside the active-ingredient limitation
Same active ingredient with different dose	Could avoid claim 2 but not necessarily claim 1
Post-2005 launch	No infringement exposure from this patent

A current generic or OTC competitor would evaluate later patent families and regulatory requirements rather than Patent 4,767,612.

What geographic coverage did the patent have?

U.S. Patent 4,767,612 provided rights only in the United States. It did not create protection in Canada, Europe, Japan, or other jurisdictions.

Foreign counterpart patents, if any, would have required separate examination and could have had different:

Claim scope;
Filing dates;
Patent terms;
Validity outcomes;
Regulatory relevance; and
Expiration dates.

The U.S. expiration does not establish the status of foreign counterparts.

What manufacturing and intellectual-property barriers remain?

The expired patent no longer blocks manufacture or sale of the claimed formulation. Practical barriers can remain in other areas:

Manufacture of micronized triamcinolone acetonide;
Control of particle-size distribution;
Suspension uniformity;
Aerosol valve and actuator performance;
Dose-content uniformity;
Container compatibility;
Residual solvent control;
Sterility or microbial limits for aqueous products;
Device-drug combination testing;
FDA chemistry, manufacturing, and controls requirements; and
Later patents covering aqueous suspension systems or delivery devices.

These are regulatory and technical barriers, not continuing rights under Patent 4,767,612.

How does this patent compare with modern triamcinolone nasal spray protection?

Issue	Patent 4,767,612	Modern triamcinolone nasal spray
Delivery	Pressurized aerosol	Generally aqueous pump spray
Propellant	CFC-12	No CFC propellant
Ethanol	Required within claimed range	Not necessarily present
Active form	Micronized triamcinolone acetonide	Suspension of triamcinolone acetonide
Claim type	Method tied to composition and aerosol dispenser	Product, formulation, device, labeling, or method claims
Patent status	Expired	Depends on later patent families
Biosimilar relevance	None	None
Current blocking effect	None	Requires product-specific review

Key Takeaways

U.S. Patent 4,767,612 claims a method of treating allergic rhinitis with a CFC-propelled nasal aerosol containing micronized triamcinolone acetonide.
Claim 1 requires specified amounts of active ingredient, anhydrous ethanol, dichlorodifluoromethane, and optional sorbitan trioleate.
Claim 2 adds a daily dose range of 200 to 1,600 micrograms.
The patent issued on August 30, 1988, and ordinarily expired on August 30, 2005.
The patent does not cover all triamcinolone acetonide nasal sprays.
Modern aqueous pump sprays are technically different from the claimed CFC aerosol.
The patent creates no current Paragraph IV, Orange Book, generic-launch, or litigation barrier.
Triamcinolone acetonide is a small molecule, so biosimilar analysis is not applicable.
Current freedom-to-operate work should focus on later formulation, device, manufacturing, and method-of-use patents.

FAQs

Does U.S. Patent 4,767,612 cover Nasacort Allergy 24HR?

No current blocking right arises from the patent. Nasacort Allergy 24HR uses a modern nasal spray platform that is materially different from the claimed CFC-12 aerosol formulation, and Patent 4,767,612 expired in 2005.

Can a company manufacture the exact formulation claimed in Patent 4,767,612?

Yes, the expired patent no longer prevents manufacture or sale in the United States. Separate FDA, environmental, manufacturing, and product-safety requirements still apply, particularly to CFC-containing products.

Does the patent cover triamcinolone acetonide aqueous suspension?

No. The claims require an aerosol dispenser and dichlorodifluoromethane. An aqueous pump suspension is outside the express formulation architecture, subject to detailed claim construction and any separate later patents.

Is a Paragraph IV certification still necessary for this patent?

No practical Paragraph IV challenge is required for an expired patent. An applicant must evaluate currently listed, unexpired patents associated with the relevant approved product.

Can the patent support a patent-infringement lawsuit today?

No. The patent’s enforceable term ended in 2005. It can remain relevant as prior art or historical evidence, but it cannot provide a current enforceable exclusionary right.

References

U.S. Patent No. 4,767,612. (1988). Triamcinolone acetonide nasal aerosol. United States Patent and Trademark Office.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. FDA.
U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs. FDA.
U.S. Environmental Protection Agency. (n.d.). Protection of stratospheric ozone: Medical products and ozone-depleting substances. EPA.
World Health Organization. (1987). Montreal Protocol on substances that deplete the ozone layer. United Nations Environment Programme.

Details for Patent: 4,767,612

Summary for Patent: 4,767,612