US Patent 9,610,265: Claim Scope, Exclusivity, Orange Book Status, and Generic Entry Risk

US Patent 9,610,265 protects a method of treating pain by administering intravenous acetaminophen at a defined dose to a human weighing at least 50 kg together with an opioid analgesic. The patent does not broadly claim acetaminophen, an opioid, or an acetaminophen-opioid product. Its principal value is a method-of-use position directed to the dosing, route, patient weight, and temporal relationship between intravenous acetaminophen and opioid administration.

The patent issued April 4, 2017, from a continuation-type prosecution chain claiming priority to a July 31, 2008 provisional filing. Its expected patent-term expiry is July 31, 2029, subject to any applicable patent-term adjustment or disclaimer. The claims are closely aligned with the adult dosing regimen for OFIRMEV, Mallinckrodt’s intravenous acetaminophen product.

What does US Patent 9,610,265 cover?

The patent’s independent claim covers each of the following elements:

Required element	Scope
Patient	Human subject weighing at least 50 kg
Condition	Pain
First composition	About 500 mg to about 750 mg acetaminophen
Route	Intravenous administration
Second composition	Opioid analgesic
Relationship	The acetaminophen and opioid are co-administered
Therapeutic purpose	Treatment of pain

Claim 1 is a method claim. It requires performance of the claimed treatment steps. A party generally does not infringe merely by manufacturing or selling acetaminophen injection unless its conduct supports induced or contributory infringement.

The claim is narrower than a general claim to intravenous acetaminophen because it requires:

A patient weighing at least 50 kg.
A dose of approximately 500 mg to 750 mg.
Intravenous administration of the acetaminophen.
Concurrent or coordinated administration of an opioid.
Treatment of pain.

The claim does not require a specific opioid, a specific opioid dose, a particular order of administration, or a single combined product.

What are the dependent claims and how do they narrow the patent?

Claims 2 through 20 define dosing schedules, acetaminophen amounts, opioid identity, administration routes, simultaneous administration, sequential administration, and timing.

Claims	Limitation
2	Repeated administration at least once every four hours for 24 hours
3	Less than 4 grams of acetaminophen in 24 hours
4	At least six administrations in 24 hours
5	At least seven administrations in 24 hours
6	About 600 mg to about 700 mg acetaminophen
7	About 650 mg acetaminophen
8	Broad list of opioid analgesics
9	Narrower list including codeine, hydrocodone, morphine, oxycodone, and tramadol
10	Morphine
11	Oral, intravenous, rectal, or parenteral opioid administration
12	Single or multiple opioid doses
13-14	Simultaneous administration, including a combined IV dosage form
15-16	Sequential administration in either order
17	One minute to less than 12 hours between administrations
18	One minute to less than six hours
19	One minute to less than three hours
20	One minute to less than one hour

Claim 7 is commercially important because it captures approximately 650 mg IV acetaminophen, the standard adult dose associated with OFIRMEV for patients weighing at least 50 kg.

Claim 10 is narrower but potentially useful in hospital protocols involving IV acetaminophen and morphine. Claims 13 and 14 reach simultaneous administration and a combined IV dosage form, while claims 15 through 20 cover separate products administered sequentially.

What is the strongest claim in US Patent 9,610,265?

Claim 1 has the broadest enforceable scope because it does not impose a specific dosing frequency, opioid, administration order, or time interval. It covers any qualifying co-administration of IV acetaminophen and an opioid for pain in a human weighing at least 50 kg.

Claim 7 is likely the most commercially relevant narrow claim because it maps onto the 650 mg dose. Claim 20 is potentially important for clinical protocols that administer acetaminophen and an opioid within the same hour.

The claims have different enforcement profiles:

Claim category	Commercial relevance	Principal limitation
Claim 1	High	Requires all core elements but leaves opioid and timing broad
Claims 2-5	Medium	Require specific frequency or daily dosing
Claims 6-7	High	Closely track 600-700 mg and 650 mg dosing
Claims 8-10	Medium	Identify opioid classes or morphine
Claims 13-14	Low to medium	Require simultaneous or combined administration
Claims 15-20	High	Capture sequential administration within defined time windows

How should “about” be interpreted in the dosing claims?

The term “about” introduces a range rather than a mathematically exact amount. The practical scope of claims 1, 6, and 7 depends on the specification, prosecution history, ordinary pharmaceutical measurement tolerances, and the relevant product label.

Claim 1 recites approximately 500 mg to 750 mg. Claim 6 narrows that range to approximately 600 mg to 700 mg. Claim 7 identifies approximately 650 mg.

A product labeled at 650 mg would fall squarely within claim 7, subject to the remaining elements. A product labeled at 625 mg would likely fall within claims 1 and 6. A 1,000 mg IV acetaminophen dose would generally fall outside the literal dose range of claim 1, although claim construction and equivalents issues would depend on the evidence.

Are claims 3, 4, and 5 internally consistent?

Claims 3 through 5 create an important arithmetic limitation.

Claim 3 requires less than 4 grams of acetaminophen over 24 hours. Claim 4 requires at least six administrations in that period. Claim 5 requires at least seven administrations.

At a nominal 650 mg per dose:

Doses per 24 hours	Nominal total
5	3,250 mg
6	3,900 mg
7	4,550 mg

Therefore, a seven-dose regimen at 650 mg per dose would exceed the less-than-4-gram limitation in claim 3. Claim 5 can operate with claim 3 only if the average dose remains below approximately 571.4 mg, subject to the meaning of “about.” Claim 4 is more compatible with a 650 mg regimen because six doses total 3,900 mg.

This creates a potential claim-construction and validity issue if a party argues that claim 5 is inconsistent with the dose ranges in claim 1 or claim 7. The claims are evaluated individually, and dependent claims may introduce combinations that are commercially uncommon or technically constrained.

What opioid products fall within the patent?

Claim 8 lists a wide range of opioid analgesics, including:

Codeine
Fentanyl
Hydrocodone
Hydromorphone
Methadone
Morphine
Oxycodone
Oxymorphone
Tramadol
Tapentadol
Remifentanil
Sufentanil
Buprenorphine
Pentazocine
Nalbuphine

Claim 9 narrows the list to codeine, dihydrocodeine, hydrocodone, morphine, oxycodone, pentazocine, and tramadol. Claim 10 is limited to morphine.

The patent does not require the opioid to be administered intravenously. Claim 11 expressly permits oral, intravenous, rectal, or parenteral administration. A hospital protocol using IV acetaminophen with oral oxycodone could therefore fall within the claims if the remaining conditions are met.

Does the patent require simultaneous administration?

No. Claim 1 requires co-administration, but the dependent claims clarify that co-administration can occur simultaneously or sequentially.

Claims 15 through 20 cover sequential administration:

Claim	Time between administrations
17	About one minute to less than 12 hours
18	About one minute to less than six hours
19	About one minute to less than three hours
20	About one minute to less than one hour

The two compositions may be administered in either order under claim 16. This broadens the patent beyond fixed-dose combination products and captures routine hospital administration where IV acetaminophen is given before or after an opioid.

What formulations are protected by US Patent 9,610,265?

The patent is primarily a method-of-use patent, not a formulation patent.

It covers use of a first pharmaceutical composition containing IV acetaminophen. The composition may be a conventional IV acetaminophen formulation, while the opioid may be a separate oral, IV, rectal, or parenteral product.

Claim 14 reaches a combined IV dosage form, but it is dependent on simultaneous administration. This claim could be relevant to a co-formulated acetaminophen-opioid product, although the commercial and regulatory development burden for such a product would be substantial.

The patent does not independently claim:

The chemical structure of acetaminophen.
A generic acetaminophen injection formulation.
A specific excipient system.
A container or vial.
A manufacturing process.
A particular opioid formulation.
A fixed-dose oral acetaminophen-opioid tablet.

Those categories may be protected by separate composition, formulation, manufacturing, or product patents.

What is the FDA and Orange Book status of the patent?

OFIRMEV is an FDA-approved intravenous acetaminophen product marketed for the management of mild-to-moderate pain and as an adjunct to opioid analgesics for moderate-to-severe pain. The FDA label specifies adult and adolescent dosing based on body weight, including a 650 mg every-four-hour regimen for patients weighing at least 50 kg, with a maximum daily dose below 4 grams under the applicable labeling conditions.[2]

The patent’s claim language closely tracks that labeling architecture:

At least 50 kg.
Approximately 650 mg.
Repeated dosing.
Less than 4 grams per 24 hours.
Use with opioid analgesics.

A method-of-use patent may be listed in the FDA Orange Book when it claims an approved method of using the drug. The relevant Orange Book listing and use code should be checked against the current FDA patent-and-exclusivity data for NDA 022450 because listings, delistings, and use codes can change.[1]

FDA approval does not itself establish patent infringement. The key issue is whether an ANDA applicant’s proposed labeling instructs users to perform the patented method.

When does US Patent 9,610,265 lose exclusivity?

The expected patent expiration date is July 31, 2029, based on the claimed priority chain. The patent issued in 2017, but its term is generally measured from the earliest effective nonprovisional filing date, not the grant date.

Event	Date
Earliest priority filing	July 31, 2008
Patent grant	April 4, 2017
Expected basic patent expiry	July 31, 2029
Small-molecule regulatory exclusivity for OFIRMEV	Expired years earlier
Earliest ordinary generic entry absent litigation delay	Potentially before July 31, 2029, depending on certification and litigation

Patent-term adjustment could alter the expiration date. No patent-term extension should be assumed without confirmation in the USPTO patent record and FDA listing data.

OFIRMEV’s regulatory exclusivity and the patent are separate rights. FDA marketing exclusivity does not extend the patent term. Because acetaminophen is an established active ingredient, the product was not positioned as a new chemical entity with five years of NCE exclusivity.

Which companies are challenging the patent?

The commercial challenge risk comes from ANDA applicants seeking approval for generic acetaminophen injection. A generic applicant can:

Certify that the patent has expired.
Submit a Paragraph III certification with a post-expiration launch date.
Submit a Paragraph IV certification asserting that the patent is invalid, unenforceable, or not infringed.
Use a section viii statement to carve out a patented method, where the FDA permits the proposed labeling to omit that use.

For this patent, a section viii strategy may be difficult if the approved label itself presents IV acetaminophen as an adjunct to opioid analgesics. The co-administration language is central to the approved clinical use and may not be easily removed without creating a label that no longer supports the intended market.

A Paragraph IV certification would create potential patent litigation under 35 U.S.C. § 271(e)(2). The patent holder could sue within 45 days of receiving the required notice, triggering a statutory stay of FDA approval of up to 30 months, subject to court action and statutory exceptions.[3]

The principal litigation questions would be:

Whether the ANDA label instructs administration with an opioid.
Whether the labeled patient population includes humans weighing at least 50 kg.
Whether the labeled dose falls within approximately 500-750 mg.
Whether “adjunct to opioid analgesics” is enough to support induced infringement.
Whether the patent claims are anticipated or obvious over prior IV acetaminophen and opioid treatment protocols.
Whether the patent adequately describes and enables the claimed dosing combinations.

What Paragraph IV challenges and litigation risks exist?

The patent presents a stronger infringement case when a generic label reproduces all of the following:

A 650 mg IV acetaminophen dose.
Administration every four hours.
A maximum daily dose below 4 grams.
Use as an adjunct to opioid analgesics.
A patient population weighing at least 50 kg.

A generic label that omits the opioid-adjunct indication may reduce inducement risk, but that strategy could narrow the product’s approved commercial use and create FDA labeling issues.

The principal invalidity arguments would likely involve obviousness and written-description issues. IV acetaminophen, opioid analgesia, adult weight-based dosing, and four-hour dosing intervals were individually known concepts. The patent holder’s response would focus on the claimed combination, clinical advantages, safety profile, and the specific dosing regimen.

The most exposed claims are likely claims 1, 6, and 7 because they cover the commercially standard regimen without requiring a narrow opioid or timing limitation. Narrow claims such as claim 10 or claim 20 may be easier to avoid through prescribing instructions or product-label design.

How strong is the patent estate for OFIRMEV?

US Patent 9,610,265 should be assessed as one component of a broader OFIRMEV patent estate rather than in isolation. The estate may include related continuation patents directed to methods, dosing regimens, formulations, and other aspects of IV acetaminophen.

Estate layer	Relevance
Method-of-use patents	Protect adjunctive use with opioids and dosing schedules
Dosing patents	Protect dose, frequency, weight, and daily exposure
Formulation patents	Protect IV composition and excipient systems
Manufacturing patents	Protect production and sterile fill processes
Regulatory listing	Creates ANDA certification and litigation exposure
Trade secrets	May protect manufacturing know-how not disclosed in patents

The strength of US 9,610,265 is commercial alignment with the OFIRMEV label. Its vulnerability is that the core clinical concepts may be challenged as predictable combinations of known analgesic practices. The enforceability analysis will depend heavily on the prosecution record, cited prior art, claim amendments, and any terminal disclaimer.

How does US 9,610,265 compare with generic acetaminophen injection products?

A generic acetaminophen injection product can be pharmaceutically equivalent to OFIRMEV while still facing method-of-use patent issues.

Issue	Branded OFIRMEV	Generic acetaminophen injection
Active ingredient	Acetaminophen	Acetaminophen
Route	Intravenous	Intravenous
Dose overlap	500-750 mg and 650 mg regimens	Likely substantial
Opioid adjunct use	Expressly reflected in labeling	May be retained or carved out
Product patent risk	Controlled by patent estate	Depends on listed patents
Method-of-use risk	Protected by US 9,610,265	Depends on label and conduct
Price pressure	Brand premium	Generic substitution and hospital contracting

Because the patent claims use rather than composition alone, a generic manufacturer’s exposure depends on the proposed label and downstream clinical use. Hospitals and physicians can create practical enforcement issues even where the manufacturer attempts a label carveout.

What generic launch scenarios exist before 2029?

Three launch scenarios are commercially realistic.

Launch after patent expiry

A Paragraph III certification supports approval with launch after the patent expires. This minimizes litigation risk but postpones entry until 2029.

Paragraph IV launch after litigation

A successful Paragraph IV challenge could permit earlier launch. The generic would need to prevail on invalidity, unenforceability, or non-infringement, or obtain a settlement allowing an agreed launch date.

Section viii carveout

A generic could seek approval for uses that omit the patented opioid-adjunct method. This strategy is most viable if the FDA permits a label that does not instruct the patented use and if the remaining indication is commercially meaningful.

The highest-risk product for the patent holder is a generic label that reproduces the 650 mg, every-four-hour, under-4-gram regimen and expressly identifies use with opioid analgesics.

What licensing and settlement issues affect the patent?

No specific license or settlement terms should be inferred solely from the patent claims. Any agreement involving Mallinckrodt, Cadence Pharmaceuticals, generic manufacturers, or hospital suppliers would need to be reviewed in the Federal Trade Commission’s pharmaceutical settlement materials, district-court dockets, and the applicable FDA patent certifications.

Potential settlement structures include:

Delayed generic entry.
Authorized generic supply.
Non-exclusive licensing.
Label restrictions.
Waivers of damages.
Entry tied to another patent’s expiry.
Patent litigation dismissal without a commercial license.

A settlement that permits entry before July 31, 2029 could materially reduce the patent’s revenue value even if the patent remains formally unexpired.

What revenue exposure does the patent create?

The patent’s revenue exposure is concentrated in hospital and acute-care use of IV acetaminophen, particularly where the product is used as part of multimodal analgesia with opioids.

The most exposed commercial segments are:

Postoperative pain management.
Inpatient hospital use.
Emergency-department analgesia.
Perioperative opioid-sparing protocols.
Adult patients weighing at least 50 kg.
650 mg IV dosing every four hours.

The patent does not cover pediatric patients under 50 kg, non-IV acetaminophen, or all opioid-free use. Revenue exposure is therefore narrower than the total acetaminophen market but significant for the labeled IV hospital indication.

Key Takeaways

US Patent 9,610,265 is a method-of-use patent focused on IV acetaminophen administered with an opioid for pain.
Claim 1 requires a human weighing at least 50 kg, approximately 500-750 mg IV acetaminophen, and opioid co-administration.
Claim 7 is closely aligned with the commercially important 650 mg dose.
Claims 15-20 cover sequential dosing, including administration within less than one hour.
The patent does not broadly claim acetaminophen injection as a composition or product.
The expected expiry is July 31, 2029, subject to USPTO-confirmed patent-term adjustment.
Generic risk depends heavily on whether an ANDA label includes the opioid-adjunct use.
Paragraph IV litigation and section viii label carveouts are the principal pre-expiry entry strategies.
Claims 3 and 5 create a dosing tension because seven 650 mg doses exceed 4 grams in 24 hours.
The patent’s commercial strength comes from its close alignment with OFIRMEV’s FDA labeling.

FAQs About US Patent 9,610,265

Does US Patent 9,610,265 cover oral oxycodone with IV acetaminophen?

Yes, potentially. Claim 9 identifies oxycodone, and claim 11 permits the opioid to be administered orally. The other claim elements must also be met.

Can a generic sell IV acetaminophen without infringing this patent?

Potentially. The patent does not claim the product alone. Risk increases if the generic label instructs use with an opioid in a qualifying patient and dose range.

Does the patent cover a 1,000 mg IV acetaminophen dose?

Not literally under claim 1’s approximately 500-750 mg range. A separate patent or infringement theory would be required.

Does the patent cover administering the opioid before acetaminophen?

Yes. Claim 16 expressly permits either the first or second composition to be administered first.

Is US Patent 9,610,265 a biosimilar patent?

No. Acetaminophen is a small-molecule active ingredient, and generic acetaminophen injection is reviewed through the ANDA pathway rather than the biosimilar pathway.

References

U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: The Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
U.S. Food and Drug Administration. (2023). OFIRMEV (acetaminophen) injection prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/
U.S. Patent No. 9,610,265. (2017). Methods of treating pain using acetaminophen and opioids. United States Patent and Trademark Office. https://patents.google.com/patent/US9610265B2/en
U.S. Food and Drug Administration. (2024). Hatch-Waxman amendments and abbreviated new drug applications. https://www.fda.gov/drugs/fdas-drug-approval-process-generic-drugs/abbreviated-new-drug-application-anda
U.S. Code, 35 U.S.C. §§ 156, 271(e), 282, and 284. (2024). Patent term, abbreviated applications, defenses, and remedies. https://uscode.house.gov/、】【

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Mallinckrodt Hosp	OFIRMEV	acetaminophen	SOLUTION;INTRAVENOUS	022450-001	Nov 2, 2010		DISCN	Yes	No	9,610,265*PED	⤷ Start Trial			Y		⤷ 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
Canada	2705733	⤷ Start Trial
Japan	2011503198	⤷ Start Trial
Japan	5909750	⤷ Start Trial
World Intellectual Property Organization (WIPO)	2009064928	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,610,265

Which drugs does patent 9,610,265 protect, and when does it expire?

Summary for Patent: 9,610,265