United States Patent 4,062,966: Scope, Claims, Tioconazole Coverage, and Patent Landscape

U.S. Patent No. 4,062,966 is a foundational imidazole-antifungal compound patent assigned to Janssen Pharmaceutica. Its claims cover a broad genus of 1-aryl-2-(1-imidazolyl)alkyl ethers and thioethers, including specific thienyl derivatives. Claim 11 appears to cover tioconazole, the active ingredient in products such as Vagistat-1. The patent issued in 1977 and expired in 1994 under the pre-Uruguay Round patent term of 17 years from grant. It no longer creates an enforceable U.S. patent barrier.

The patent remains commercially important as an origin-of-rights document because it identifies the chemical genus, specific tioconazole compounds, pharmaceutical compositions, and systemic or oral antifungal treatment methods.

What does U.S. Patent 4,062,966 cover?

The patent has three principal claim categories:

Claim category	Claims	Subject matter
Chemical genus	1-8	1-aryl-2-(1-imidazolyl)alkyl ethers and thioethers
Specific compounds	9-16	Named thienyl and halothienyl imidazole derivatives
Pharmaceutical use	17-18	Dosage-unit compositions and treatment of fungal infections

The independent chemical claim, claim 1, requires all of the following elements:

A 1-aryl-2-(1-imidazolyl)alkyl structure.
An ether or thioether linkage, represented by Z as oxygen or sulfur.
An aryl or heteroaryl group represented by Ar.
A thienyl or substituted thienyl group represented by Y.
Alkyl substituent options on R1 through R4.
One or two carbon atoms in the variable chain represented by n.
A pharmaceutically acceptable acid-addition salt.

The claim is chemically broad because it covers multiple substituent classes rather than one named active ingredient.

Which compounds fall within the patent claims?

Claim 1 chemical genus

Claim 1 covers compounds with the following variable ranges:

Variable	Claimed alternatives
R1-R4	Hydrogen or C1-C6 alkyl
Ar	Phenyl, substituted phenyl, thienyl, or halothienyl
Ar substituents	Halogen, C1-C6 alkyl, or C1-C6 alkoxy
Z	Oxygen or sulfur
n	1 or 2
Y	Thienyl or substituted thienyl
Y substituents	Halogen, C1-C6 alkyl, or C1-C6 alkoxy

The genus includes both oxygen-linked ethers and sulfur-linked thioethers. It also covers unsubstituted and substituted aromatic groups, including halogenated phenyl and thienyl structures.

Dependent claims 2 through 8

Claims 2 through 8 narrow the genus:

Claim 2 limits Ar to phenyl or substituted phenyl.
Claim 3 limits Z to oxygen.
Claim 4 limits Z to sulfur.
Claim 5 requires R1, R2, R3, and R4 to be hydrogen.
Claim 6 specifies a 2,4-dichlorophenyl Ar group.
Claim 7 limits n to 1.
Claim 8 limits Y to thienyl or halothienyl.

These claims create overlapping fallback positions. A compound may fall within claim 1 and one or more dependent claims simultaneously.

Does U.S. Patent 4,062,966 cover tioconazole?

Yes. Claim 11 recites:

"1-[2,4-dichloro-beta-(2-chloro-3-thienylmethoxy)phenethyl]imidazole."

This corresponds to tioconazole, commonly identified chemically as 1-[2-[(2-chloro-3-thienyl)methoxy]-2-(2,4-dichlorophenyl)ethyl]-1H-imidazole.

The claim elements align as follows:

Tioconazole feature	Claim 11 limitation
Imidazole ring	1-phenethyl imidazole
2,4-Dichlorophenyl group	Ar
Ether linkage	Z = oxygen
2-Chloro-3-thienyl group	Y
One-carbon methylene linker	n = 1
Unsubstituted side-chain positions	R1-R4 = hydrogen

Claim 11 is a compound claim directed specifically to tioconazole. Claims 1, 3, 5, 6, 7, and 8 also appear to encompass the same compound through their broader limitations.

What other named compounds are claimed?

Claims 9 through 16 identify related imidazole antifungal compounds.

Claim	Named structure or structural class
9	3-Thienylmethoxy derivative
10	5-Chloro-2-thienylmethoxy derivative
11	2-Chloro-3-thienylmethoxy derivative, corresponding to tioconazole
12	2-Thienylmethoxy derivative
13	2,5-Dichloro-3-thienylmethoxy derivative
14	5-Chloro-2-thienylmethylthio derivative
15	3-Thienylmethylthio derivative
16	A more highly substituted imidazole ether containing two thienyl groups

The patent therefore is broader than a tioconazole patent in the narrow sense. It claims a family of structurally related imidazole antifungals, with both ether and thioether members.

How strong is the patent estate for tioconazole?

The patent estate was strong at issuance because it combined:

A broad Markush genus in claim 1.
Narrower dependent claims directed to favored substitution patterns.
Multiple specific compound claims.
Pharmaceutical composition protection.
Therapeutic method claims.

The strongest historical claims were likely claims 11 and the overlapping genus claims. A specifically named compound claim generally provides a clearer infringement theory than a broad Markush claim because it avoids disputes over whether a particular substitution pattern falls within the genus.

The patent also used multiple claim types to address different commercial activities:

Commercial activity	Relevant claims
Making or selling tioconazole	1, 3, 5-8, 11
Selling a different claimed thienyl analogue	1-8, 9-16
Formulating a claimed compound	17
Administering a claimed compound for fungal infection	18
Producing an acid-addition salt	1 and related dependent claims

The principal weakness today is term expiration. Claim breadth and historical validity no longer create a current enforcement right after expiration.

When did U.S. Patent 4,062,966 lose exclusivity?

U.S. Patent 4,062,966 issued in December 1977. Under the patent term rules applicable to patents filed before June 8, 1995, the patent generally had a term of 17 years from grant. On that basis, the patent expired in December 1994.

Event	Approximate date
Priority and development period	Early to mid-1970s
U.S. patent filing	Mid-1970s
Patent grant	December 1977
Statutory term	17 years from grant
U.S. expiration	December 1994
Current status	Expired

Patent expiration eliminates the right to exclude others from making, using, selling, offering for sale, or importing the claimed compounds in the United States. The expiration does not eliminate the patent's historical relevance or its value as prior art.

No patent-term adjustment under the modern term framework should be assumed for this patent. Patent-term adjustment was introduced for later-filed applications and does not generally extend a pre-1995 patent beyond its applicable statutory term.

What is the Orange Book status of tioconazole?

Tioconazole is a small-molecule antifungal, not a biologic. Biosimilar exclusivity rules therefore do not apply. Any abbreviated approval pathway would be an ANDA or another small-molecule pathway, not a biosimilar application under the Public Health Service Act.

U.S. Patent 4,062,966 should not be treated as a current Orange Book blocking patent because it expired in 1994. An expired patent may appear in historical regulatory or patent records, but it cannot support a current Paragraph IV certification challenge in the ordinary sense.

Orange Book relevance depends on the specific approved product and dosage form. Tioconazole has been marketed primarily in topical products, including vaginal formulations. A topical product may have a different regulatory history from an oral systemic product, and the presence or absence of a listing depends on the approved application and the reference product's regulatory status.

Are there current Paragraph IV risks based on this patent?

No current Paragraph IV risk arises from U.S. Patent 4,062,966 alone because the patent has expired.

Historically, a generic applicant could have addressed the patent through:

A Paragraph III certification, with approval delayed until expiration.
A Paragraph IV certification, alleging that the patent was invalid, unenforceable, or not infringed.
A section viii statement, if the listed patent covered a method of use omitted from the proposed label.

The patent's expiration would have removed the need for a Paragraph IV challenge directed solely to this patent. Any present generic-entry analysis must instead examine later patents, regulatory exclusivities, formulation rights, trademarks, product-specific labeling, and manufacturing know-how.

What formulation patents protect tioconazole products?

The supplied claims include a composition claim, claim 17, but it is not a detailed formulation claim. Claim 17 covers a dosage-unit composition containing:

A pharmaceutical carrier; and
Approximately 10 mg to 3,000 mg of a compound covered by claim 1.

The claim does not specify a particular cream, ointment, suppository, tablet, capsule, solvent system, surfactant, particle size, release profile, or vaginal delivery vehicle. Its formulation scope is therefore functional and quantity-based rather than excipient-specific.

Claim 17 could historically have reached a dosage form containing tioconazole within the stated quantity range. It does not, on its face, distinguish among common topical carriers. It also does not establish protection for a modern formulation unless the formulation contains a claimed compound and satisfies the dosage-unit limitation.

A current freedom-to-operate review for tioconazole topical products would need to separate:

Active-ingredient patents.
Cream or ointment formulation patents.
Vaginal delivery or applicator patents.
Manufacturing-process patents.
Packaging and device patents.
Trademark and trade-dress rights.

U.S. Patent 4,062,966 addresses the first category and, in limited form, the composition category.

What method-of-use rights are claimed?

Claim 18 covers a method of treating fungal infections in animals by orally or parenterally administering an antifungal-effective amount of a claim 1 compound.

Its principal limitations are:

The subject is an animal.
The indication is a fungal infection.
Administration is oral or parenteral.
The dose must be antifungally effective.
The administered compound must fall within claim 1.

The claim does not expressly limit treatment to a particular fungal species, anatomical site, disease severity, dosage schedule, or treatment duration. It is therefore broad as a method claim, although its practical scope is limited by the patent's expiration and by the claim's oral or parenteral route requirement.

A topical tioconazole product would not necessarily satisfy claim 18 because the claim expressly identifies oral or parenteral administration. Claim 17 is more relevant to dosage-unit products, while claim 11 is the most direct claim for the tioconazole molecule.

Does the patent cover miconazole or econazole?

The patent should not automatically be treated as a core patent for every imidazole antifungal.

Miconazole and econazole have different structures from the named thienyl derivatives in claims 9 through 16. The broad genus in claim 1 may be relevant only if the exact molecular structure satisfies every limitation, including the required thienyl or substituted thienyl Y group. A compound with a phenyl substituent in the position required for Y would not meet that limitation.

Drug	General structural distinction	Likely relationship to U.S. 4,062,966
Tioconazole	Chlorinated thienyl ether imidazole	Specifically claimed by claim 11
Miconazole	Dichlorophenyl ether imidazole	Not a named claim 9-16 compound; requires element-by-element analysis
Econazole	Chlorophenyl ether imidazole	Not specifically named; claim coverage cannot be assumed
Clotrimazole	Triphenyl imidazole derivative	Structurally distinct from the claimed thienyl ether genus

The key issue is the identity and position of the Y thienyl group. Patent infringement analysis must compare the accused molecule against every limitation rather than rely on the shared imidazole pharmacophore.

What is the geographic scope of the patent?

The patent's enforceable rights were limited to the United States. Corresponding foreign applications may have produced national patents in other jurisdictions, but U.S. Patent 4,062,966 itself did not create rights in Europe, Canada, Japan, or other markets.

Geographic analysis should distinguish among:

U.S. compound rights.
Foreign national equivalents.
Patent term differences.
Supplementary protection certificates.
Local formulation patents.
Regulatory exclusivity periods.
Manufacturing patents in jurisdictions supplying the U.S. market.

Any foreign equivalent would require separate review of its grant, claim amendments, maintenance payments, and expiration date. The expiration of the U.S. patent does not establish the status of foreign family members.

Are there licensing deals or patent settlements?

The patent text does not establish a license, assignment history beyond the named patent owner, Paragraph IV settlement, or commercial supply agreement. Patent ownership and licensing must be distinguished. Janssen's historical ownership of the patent does not by itself prove that every tioconazole product was manufactured or sold by Janssen, nor does it establish the terms of any downstream license.

Because the patent expired before the modern Hatch-Waxman settlement-reporting regime became a central feature of generic litigation, current commercial analysis should focus on later product-specific agreements rather than assume that this patent generated an active settlement structure.

What generic launch risks exist for tioconazole?

The expired patent creates no current generic launch block. Remaining entry risks are likely to arise from commercial and regulatory execution rather than the expired compound patent.

Risk category	Relevance
Expired compound patent	No current blocking effect
Biosimilar pathway	Not applicable
Paragraph IV challenge to this patent	No current need based on expiration
Later formulation patents	Product-specific review required
Topical equivalence requirements	Potentially significant
Vaginal delivery system	May create device or formulation issues
OTC monograph compliance	May determine marketing route
Manufacturing process	May create separate IP barriers
Trademark rights	Can affect branding, not generic entry
Market size	Likely limits commercial incentive more than patent term

For a topical antifungal, demonstrating pharmaceutical equivalence and therapeutic equivalence can be more complex than for a conventional immediate-release oral tablet. The relevant regulatory burden may involve the vehicle, dosage form, local delivery, microbiological quality, and product performance.

What is the current patent strength of U.S. 4,062,966?

The patent has no current exclusionary strength because it is expired. Its historical claim strength was high for compounds matching the defined imidazole-thienyl ether and thioether structures, particularly tioconazole under claim 11.

Metric	Assessment
Historical genus breadth	Broad
Specific tioconazole protection	Direct, through claim 11
Formulation specificity	Limited
Method-of-use breadth	Broad but route-limited
Current enforceability	None after expiration
Prior-art value	Potentially significant
Current generic barrier	None from this patent

Key Takeaways

U.S. Patent 4,062,966 claims a broad genus of imidazole-containing aryl ethers and thioethers.
Claim 11 specifically covers tioconazole.
Claims 1, 3, 5, 6, 7, and 8 also appear to read on tioconazole through overlapping limitations.
Claim 17 covers dosage-unit compositions containing 10 mg to 3,000 mg of a claimed compound.
Claim 18 covers oral or parenteral treatment of fungal infections in animals.
The patent issued in 1977 and expired in 1994 under the applicable 17-year patent term.
It is not a current Orange Book barrier and cannot independently support a present Paragraph IV challenge.
Biosimilar analysis is not relevant because tioconazole is a small molecule.
Current freedom-to-operate analysis should focus on later formulation, delivery-device, manufacturing, regulatory, and trademark rights.

FAQs

Is tioconazole still protected by U.S. Patent 4,062,966?

No. The patent expired in 1994. Claim 11 historically covered tioconazole, but the expired patent no longer confers enforceable U.S. exclusivity.

Does claim 17 cover tioconazole cream?

It may have covered a dosage-unit composition containing tioconazole if the product satisfied the claim's compound, carrier, and quantity limitations. The claim does not specify a particular cream base or excipient system.

Can a company launch a tioconazole generic without a Paragraph IV challenge?

Yes, as to U.S. Patent 4,062,966, because the patent has expired. Later patents and regulatory requirements must be assessed separately.

Is tioconazole subject to biosimilar competition?

No. Tioconazole is a chemically synthesized small molecule. Competition would proceed through generic-drug pathways rather than biosimilar approval.

Does the patent cover topical administration?

The chemical claims and composition claim may cover a topical product depending on the product's structure and dosage-unit characteristics. Claim 18 specifically recites oral or parenteral administration and does not expressly cover topical treatment.

References

United States Patent and Trademark Office. (1977). U.S. Patent No. 4,062,966, 1-aryl-2-(1-imidazolyl)alkyl ethers and thioethers.
United States Patent and Trademark Office. (n.d.). Patent term adjustment and patent term calculation resources. https://www.uspto.gov/patents/laws/patent-term-calculator
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application process. https://www.fda.gov/drugs/types-applications/abbreviated-new-drug-application-anda
U.S. Food and Drug Administration. (n.d.). Biosimilar and interchangeable products. https://www.fda.gov/drugs/biosimilars/biosimilar-biological-products
World Intellectual Property Organization. (n.d.). PATENTSCOPE patent search database. https://patentscope.wipo.int

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	17922/75	Apr 30, 1975

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	212592	⤷ Start Trial
Austria	350551	⤷ Start Trial
Austria	A310276	⤷ Start Trial
Australia	1319976	⤷ Start Trial
Belgium	841309	⤷ Start Trial
Bulgaria	25517	⤷ Start Trial
Canada	1063123	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 4,062,966

Summary for Patent: 4,062,966