United States Patent 8,318,817: Scope, Claims, Expiration, Orange Book Status, and Otiprio Patent Landscape

US Patent No. 8,318,817 protects a method of treating otic infection or inflammation with a single intratympanic injection of a thermosensitive, sustained-release formulation. The claim requires a multiparticulate antimicrobial, a polyoxyethylene-polyoxypropylene copolymer, low osmolarity, defined viscosity and gelation parameters, room-temperature administration, and release for at least five days. The patent is closely associated with ciprofloxacin otic suspension administered during tympanostomy tube surgery, including the FDA-approved product Otiprio.

The principal commercial claim risk is concentrated in claim 11, which covers treatment of otitis media with effusion associated with tympanostomy tube insertion. The patent is a small-molecule formulation and method-of-use patent, not a biologic patent. Its reported Orange Book expiration date is January 26, 2027. [1,2]

What does US Patent 8,318,817 protect?

US 8,318,817 protects a method of treating an otic infection or inflammation by intratympanically administering a specific in situ gelling formulation.

The independent claim requires all of the following:

Claim limitation	Required scope
Therapeutic intervention	Intratympanic administration through the tympanic membrane
Disease	Otic infection or inflammation
Active ingredient	A therapeutically effective amount of a multiparticulate antimicrobial agent
Polymer	A copolymer of polyoxyethylene and polyoxypropylene
Injection properties	Non-gelation viscosity permitting injection through an 18- to 31-gauge needle
Gel properties	Gelation viscosity of approximately 15,000 to 1,000,000 cP
Gelation temperature	Between approximately room temperature and body temperature
Osmolarity	Less than 1,000 mOsm/L
Administration state	Liquid at approximately room temperature and administered at approximately room temperature
Duration	Sustained release in the ear for at least five days after one administration

The patent therefore does not cover every ciprofloxacin otic product, every intratympanic injection, or every poloxamer formulation. A potentially infringing product would need to practice the claimed combination, either literally or under an equivalent theory.

How do claims 1 through 11 narrow the patent scope?

Claim 1 establishes the core method. Claims 2 through 11 progressively narrow the antimicrobial, polymer, disease, and surgical context.

Claim	Limitation	Commercial significance
1	Core intratympanic sustained-release method	Broadest enforceable method claim
2	Release for at least 10 days	Covers longer-duration formulations
3	Antimicrobial is an antibiotic	Excludes non-antibiotic antimicrobial agents
4	Antibiotic is a quinolone	Targets the principal otic antibiotic class
5	Lists specific quinolones	Includes ciprofloxacin, ofloxacin, levofloxacin, moxifloxacin and others
6	Quinolone is ciprofloxacin	Directly targets ciprofloxacin products
7	Copolymer is poloxamer 407	Covers a commercially important thermosensitive excipient
8	Disease is otitis media	Narrows the indication
9	Disease is otitis media with effusion	Covers OME treatment
10	Condition is associated with an otic intervention	Links treatment to surgery or another procedure
11	OME associated with tympanostomy tube surgery	Closest claim to Otiprio’s labeled use

Claim 11 is materially narrower than claim 1 because it requires both otitis media with effusion and an association with surgery for tympanostomy tube insertion. A generic or follow-on product could avoid claim 11 by targeting a different disease, using a different procedure, or demonstrating that its formulation does not satisfy the required release and rheological limitations. It would still need to avoid the broader claims.

What formulation characteristics are protected?

The patent’s formulation protection is defined through physical performance rather than only ingredient identity.

Poloxamer 407 and thermosensitive gelation

Claim 7 identifies poloxamer 407, also known as Pluronic F127, as the relevant polyoxyethylene-polyoxypropylene copolymer. The formulation is intended to remain injectable as a liquid at room temperature and become substantially more viscous after exposure to body temperature.

That design creates a delivery sequence:

The product is drawn into a syringe and injected through the tympanic membrane.
The formulation remains sufficiently fluid for administration through a fine-gauge needle.
Exposure to body temperature increases viscosity.
The gel or high-viscosity depot retains the antimicrobial in the middle ear.
The drug is released over at least five days, and under claim 2, at least 10 days.

The patent does not require a single numerical concentration of poloxamer 407 in the claims provided. It instead requires the resulting viscosity, gelation temperature, and injection performance.

Multiparticulate antimicrobial agent

The term “multiparticulate” limits the claim to an antimicrobial presented in multiple particles or particulate units. The claim language can cover a suspension of drug particles in the polymer vehicle. A fully dissolved antimicrobial formulation may present a noninfringement position if it does not satisfy the ordinary meaning of “multiparticulate,” although the precise outcome would depend on the specification and prosecution history.

Osmolarity below 1,000 mOsm/L

The osmolarity ceiling is a substantive claim limitation. A formulation above that value would not literally satisfy claim 1. The limitation also distinguishes the claimed formulation from highly concentrated or hyperosmolar delivery systems that may create tolerability concerns in the middle ear.

Sustained release

The release requirement is functional. The product must provide sustained release in the ear for at least five days after a single administration. Claim 2 extends the period to at least 10 days.

An accused product could face testing disputes over:

The definition of “sustained release.”
Whether release must be measured in vivo or can be established through in vitro testing.
The meaning of “in the ear.”
The relevant antimicrobial concentration-time profile.
Whether a formulation that persists physically but releases drug rapidly satisfies the limitation.

What is the relationship between US 8,318,817 and Otiprio?

Otiprio is ciprofloxacin otic suspension, 6%, approved by the FDA for administration into the middle ear during tympanostomy tube placement in pediatric patients with bilateral otitis media with effusion. The FDA label describes a single intraoperative administration and identifies poloxamer 407 among the inactive ingredients. [2]

The product aligns closely with the dependent claim structure:

Otiprio characteristic	Relevant patent limitation
Ciprofloxacin	Claims 5 and 6
Otic suspension	Multiparticulate antimicrobial formulation
Poloxamer 407	Claim 7
Intratympanic administration	Claim 1
Otitis media with effusion	Claim 9
Tympanostomy tube surgery	Claims 10 and 11
Single administration	Claim 1
Sustained local exposure	Claims 1 and 2

The strongest product-specific overlap is therefore with claims 6, 7, 9, and 11. The independent claim remains important because it covers other listed quinolones and broader otic infection or inflammation indications.

When does US Patent 8,318,817 lose exclusivity?

The reported Orange Book patent expiration date for US 8,318,817 is January 26, 2027. [1] The practical exclusivity date can be affected by patent-term adjustment, patent-term extension, terminal disclaimers, or later legal events. The patent’s Orange Book listing, USPTO Patent Center record, and applicable FDA patent data should control for launch planning. [1,3]

Exclusivity timeline

Event	Date or status
US patent grant	November 27, 2012
FDA approval of Otiprio	December 2015
Reported Orange Book patent expiration	January 26, 2027
Expected post-expiration opportunity	Generic or alternative product entry, subject to FDA approval and other patents

Patent expiration does not automatically create an immediate launch opportunity. A follow-on product must address any later-issued patents, regulatory exclusivity, formulation differences, and patent certifications.

What is the Orange Book status of the patent?

US 8,318,817 is listed in the FDA Orange Book for Otiprio, NDA 207986. The listed use is directed to treatment of otitis media with effusion in pediatric patients undergoing tympanostomy tube surgery. [1]

The listing is significant because it can require an abbreviated new drug application applicant to submit a patent certification. A Paragraph IV certification would assert that the listed patent is invalid, unenforceable, or not infringed. Filing a Paragraph IV certification can trigger patent litigation and, if suit is filed within the statutory period, a regulatory stay of approval for up to 30 months under the Hatch-Waxman framework.

The patent’s method-of-use character also matters. A generic applicant could pursue a section viii “carve-out” for a patented use if the remaining labeling omits the protected indication. That strategy is difficult where the listed patent covers the principal commercial use, particularly when the product is designed for intraoperative treatment of otitis media with effusion.

Which companies are challenging US 8,318,817?

No established public Paragraph IV litigation involving US 8,318,817 is identified in the cited FDA and public patent materials reviewed for this analysis. The absence of an identified case does not establish that no certification has been filed or that no dispute exists. The relevant diligence record is the current FDA Orange Book, FDA patent certification information, USPTO Patent Center, and federal court docket data. [1,3,4]

The commercial field has been affected more by the originator’s corporate and product strategy than by a publicly established generic challenge. Otonomy developed Otiprio and related otic delivery technologies. The product’s narrowly defined surgical indication limits the number of economically attractive generic approaches, but the patent also creates a clear target for a formulation or method-of-use challenge.

How strong is the patent estate for Otiprio?

US 8,318,817 is strongest against a product that replicates the full delivery architecture:

Ciprofloxacin particles.
Poloxamer 407.
Room-temperature liquid administration.
Intratympanic injection.
In situ gelation at ear temperature.
Sustained release for at least five days.
Use during tympanostomy tube surgery for otitis media with effusion.

Its strength is lower against products that use different delivery technologies, such as:

Biodegradable microspheres.
Drug-eluting tympanostomy tubes.
Non-gelling suspensions.
Liposomal or nanoparticle systems.
A dissolved-drug solution without multiparticulate material.
A formulation administered topically rather than intratympanically.
A product directed to an indication outside otitis media with effusion.

The patent is technically narrower than a composition patent that covers the drug and excipient combination regardless of use. Because it is a method claim, infringement generally requires performance of the claimed administration and treatment steps.

What generic launch risks exist?

A generic applicant would likely face four principal risks.

Formulation equivalence

The applicant must develop a formulation that meets FDA requirements while determining whether its rheology, particle structure, osmolarity, gelation behavior, and release profile fall within the patent claims.

Labeling overlap

A product label that includes pediatric otitis media with effusion associated with tympanostomy tube placement would closely approach claim 11. A carve-out may be commercially unattractive if that indication represents the product’s principal use.

Paragraph IV litigation

A Paragraph IV challenge could contest:

Anticipation by prior art.
Obviousness of combining ciprofloxacin, poloxamer 407, and intratympanic delivery.
Written description or enablement.
Definiteness of the viscosity, gelation, and sustained-release limitations.
Noninfringement based on formulation or administration differences.
Patent-term or listing issues.

Later patents

The 2027 expiration date for US 8,318,817 does not establish freedom to operate against the full Otiprio patent family. Continuations, divisionals, formulation patents, manufacturing patents, and later method-of-use patents must be reviewed separately.

What patent litigation and settlement issues matter?

A settlement involving a generic applicant could establish an agreed launch date before January 2027, impose supply or licensing conditions, or preserve the patent owner’s right to enforce related patents. No publicly confirmed settlement concerning this patent is included in the cited record.

For diligence, the material documents are:

Any ANDA notice letter.
The patent owner’s complaint.
The Orange Book listing history.
The FDA approval or tentative-approval record.
Any stipulated judgment or settlement.
Any covenant not to sue.
Any license or assignment affecting Otiprio rights.

Without those documents, a market-entry date should not be inferred from patent expiration alone.

Does biosimilar risk apply to US 8,318,817?

No. Otiprio contains ciprofloxacin, a small-molecule antibiotic. It is regulated through the conventional drug approval pathway rather than the biologics license application and biosimilar pathway.

The relevant competitive threats are:

ANDA-based generic ciprofloxacin otic products.
505(b)(2) products using a modified intratympanic formulation.
New drug applications for alternative sustained-release otic systems.
Drug-eluting tympanostomy tubes.
Non-antibiotic products that reduce the need for intraoperative antimicrobial delivery.

What licensing and commercial rights are relevant?

Otonomy is the principal company associated with Otiprio and the underlying sustained-release otic technology. The commercial value of US 8,318,817 is tied to the Otiprio franchise, the product’s FDA-approved surgical indication, and related intellectual property rather than to broad protection for all otic ciprofloxacin products.

Revenue exposure depends on:

Otiprio net sales before generic entry.
The proportion of sales generated by the patented indication.
Payer coverage for intraoperative use.
Pediatric tympanostomy procedure volume.
Hospital and ambulatory surgery center purchasing.
Whether a competitor offers a lower-cost formulation or a different delivery system.

The patent’s geographic protection is limited to the United States. Foreign counterparts must be assessed separately by jurisdiction, with particular attention to European, Canadian, Japanese, and other national-phase rights, maintenance payments, and local validity decisions.

Key Takeaways

US 8,318,817 is a method patent covering intratympanic administration of a thermosensitive, sustained-release antimicrobial formulation.
The formulation must satisfy specific injection, gelation, viscosity, osmolarity, and release limitations.
Ciprofloxacin and poloxamer 407 are expressly covered by claims 6 and 7.
Claim 11 most closely tracks Otiprio’s use during tympanostomy tube surgery for otitis media with effusion.
The reported Orange Book expiration date is January 26, 2027.
The patent is not a biosimilar patent; generic and 505(b)(2) pathways are the relevant competitive routes.
A follow-on product may attempt a Paragraph IV challenge, a section viii labeling carve-out, or a noninfringing formulation design.
Patent expiration does not resolve later-family, formulation, manufacturing, licensing, or regulatory barriers.

FAQs

Can a ciprofloxacin ear product infringe US 8,318,817 without using poloxamer 407?

Yes, potentially. Claim 1 requires a polyoxyethylene-polyoxypropylene copolymer but does not require poloxamer 407 specifically. A different copolymer could fall within the independent claim if it satisfies the remaining limitations.

Does topical ear-drop administration infringe the patent?

Generally, the supplied claims require intratympanic administration through the tympanic membrane. A conventional external-ear or middle-ear topical product would have a strong noninfringement position on the administration limitation, subject to the facts of its delivery method.

Is a five-day release period enough for infringement?

Yes. Claim 1 requires release for at least five days. Claim 2 requires at least 10 days. A product releasing antimicrobial for five through nine days could fall within claim 1 but not claim 2, assuming all other limitations are met.

Can a product avoid claim 11 by treating otitis media without tympanostomy surgery?

Potentially. Claim 11 specifically requires otitis media with effusion associated with surgery for insertion of a tympanostomy tube. Treatment outside that surgical context may avoid claim 11 while remaining subject to broader claims.

What is the most important technical design-around for a competitor?

The most direct design-around is to change one or more claim-critical characteristics, such as using a non-gelling vehicle, a non-multiparticulate drug, a delivery system other than intratympanic injection, a different release mechanism, or an indication outside the claimed surgical OME use.

References

U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Otiprio, NDA 207986. https://www.accessdata.fda.gov/scripts/cder/ob/
U.S. Food and Drug Administration. (2015). Otiprio (ciprofloxacin otic suspension) prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/207986s000lbl.pdf
United States Patent and Trademark Office. (2025). Patent Center: U.S. Patent No. 8,318,817. https://patentcenter.uspto.gov/
U.S. Food and Drug Administration. (2025). Patent certification and exclusivity information. https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/patent-and-exclusivity-information <|endoftext|>

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Alk Abello	OTIPRIO	ciprofloxacin	INJECTABLE, SUSPENSION;OTIC	207986-001	Dec 10, 2015		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial				TREATMENT OF OTIC INFECTION OR INFLAMMATION	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	071388	⤷ Start Trial
Argentina	072253	⤷ Start Trial
Argentina	072828	⤷ Start Trial
Australia	2009239429	⤷ Start Trial
Australia	2009246870	⤷ Start Trial
Australia	2009271129	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,318,817

Which drugs does patent 8,318,817 protect, and when does it expire?

Summary for Patent: 8,318,817