Details for Patent: 11,446,266

Which drugs does patent 11,446,266 protect, and when does it expire?

Patent 11,446,266 protects COMBOGESIC IV and is included in one NDA.

This patent has thirty-five patent family members in twenty-seven countries.

Summary for Patent: 11,446,266

Title:	Combination composition
Abstract:	An intravenous composition for providing relief for pain and/or inflammation, the composition having ibuprofen and paracetamol in combination for delivering to a human at each dose: a) approximately 125 mg to approximately 175 mg ibuprofen in combination with approximately 475 mg to approximately 525 mg paracetamol; or b) approximately 275 mg to approximately 325 mg ibuprofen in combination with approximately 975 mg to approximately 1,025 mg paracetamol.
Inventor(s):	Hartley C. Atkinson
Assignee:	AFT Pharmaceuticals Ltd
Application Number:	US16/149,109
Patent Claim Types: see list of patent claims	Use; Composition; Formulation;

US Patent 11,446,266: Claim Scope, Exclusivity, and Patent Landscape for Intravenous Ibuprofen-Paracetamol

US Patent No. 11,446,266 protects a method of treating pain by intravenous administration of an aqueous combination of ibuprofen and paracetamol, also known in the United States as acetaminophen. The claimed dose pairs are 150 mg ibuprofen/500 mg paracetamol and 300 mg ibuprofen/1,000 mg paracetamol. Claim 2 adds administration every six hours. Claims 3 and 4 restate the two dose alternatives without the six-hour limitation. [1]

The patent is directed to a fixed intravenous combination, not to ibuprofen or paracetamol generally. Its commercial importance depends on whether a competing product uses the claimed dose strengths, intravenous aqueous delivery, and treatment method in humans.

What does US Patent 11,446,266 claim?

Claim	Protected subject matter	Key limitations
1	Method of treating pain	Human patient; intravenous administration; aqueous solution; either 150 mg/500 mg or 300 mg/1,000 mg ibuprofen/paracetamol
2	Method of claim 1	Administration on a six-hour basis
3	Method of claim 1	150 mg ibuprofen plus 500 mg paracetamol
4	Method of claim 1	300 mg ibuprofen plus 1,000 mg paracetamol

Claim 1 is the principal claim. Claims 3 and 4 provide dose-specific fallback positions. Claim 2 is narrower because it requires a six-hour dosing interval.

The claims are method claims. They do not expressly claim:

• A vial or bag as a standalone product;
• A particular pH;
• A specified solvent system;
• A particular buffer;
• A manufacturing process;
• A formulation concentration;
• A specific infusion duration;
• A particular pain indication;
• A particular hospital or perioperative setting.

Those limitations may appear in the specification or related patent family members, but they are not present in the supplied claims.

How broad is claim 1?

Claim 1 has four material limitations:

1. Treatment of pain.
2. Administration to a human.
3. Intravenous administration.
4. Administration of an aqueous solution containing one of two specified dose combinations.

The claim does not appear limited to a particular type of pain. It can therefore cover acute postoperative pain, trauma-related pain, musculoskeletal pain, dental pain, emergency-department pain, and other human pain indications, provided the claimed administration method is used.

The claim also does not restrict the solution to ibuprofen and paracetamol alone. The term "comprising" generally permits additional components, subject to ordinary claim-construction principles. A competing formulation containing the claimed active ingredients plus excipients, buffers, stabilizers, or other compatible ingredients would remain within the claim if the other limitations are met.

The claim is narrower than a claim covering all intravenous ibuprofen-paracetamol combinations. It identifies two dose pairs. A product using 200 mg ibuprofen and 1,000 mg paracetamol, for example, would not literally meet either stated combination unless the dosage is administered in a way that legally satisfies one of the claimed amounts.

Dose-pair analysis

The two claimed dose pairs have the same 1:3 ibuprofen-to-paracetamol ratio:

Dose option	Ibuprofen	Paracetamol	Total active drug
Lower dose	150 mg	500 mg	650 mg
Higher dose	300 mg	1,000 mg	1,300 mg

The higher dose is exactly twice the lower dose. This supports a product strategy based on either a lower-strength unit or a higher-strength unit administered at the same ratio.

The wording "comprising 150 mg" and "comprising 300 mg" is potentially important. In patent litigation, courts may assess whether the amount limitation means an exact nominal dose, a dose containing at least that amount, or a clinically administered dose subject to ordinary manufacturing and measurement tolerances. The specification, prosecution history, and expert evidence would control that issue.

Does claim 2 cover a standard four-dose daily regimen?

Claim 2 requires administration "on a 6 hourly basis." If interpreted as one dose every six hours, the regimen would ordinarily produce four administrations in 24 hours.

Regimen	Daily ibuprofen	Daily paracetamol
150 mg/500 mg every six hours	600 mg	2,000 mg
300 mg/1,000 mg every six hours	1,200 mg	4,000 mg

The high-dose option reaches 4,000 mg of paracetamol per 24 hours, a historically recognized adult maximum in some labeling contexts, although current clinical practice may use lower limits for certain patients or risk groups. The claim does not expressly state a daily maximum, patient weight, liver condition, renal status, or treatment duration.

"On a 6 hourly basis" may create issues concerning schedule precision. A regimen administered at irregular intervals, on an as-needed basis, or every four or eight hours would present a stronger non-infringement position against claim 2, although it could still fall within claim 1 if the dose and route limitations are met.

Do claims 3 and 4 add meaningful protection?

Claims 3 and 4 are narrower than claim 1 but have limited additional technical content.

• Claim 3 isolates the 150 mg/500 mg dose pair.
• Claim 4 isolates the 300 mg/1,000 mg dose pair.
• Neither claim adds the six-hour limitation.
• Both remain dependent on the human intravenous pain-treatment framework in claim 1.

Their principal value is redundancy. If a court construed claim 1's alternatives narrowly or found an issue affecting the structure of the combined limitation, the dose-specific claims could provide separate infringement positions.

Claims 3 and 4 do not independently protect a vial, bag, or prefilled syringe unless use of that product necessarily results in the claimed method and the relevant actor performs or induces the claimed administration.

What formulations are protected by US 11,446,266?

The claims cover an aqueous intravenous solution containing the specified active-dose combination. They do not, on their face, require a particular:

• Concentration;
• Container;
• Infusion volume;
• pH;
• Buffer;
• Preservative;
• Osmolality;
• Sterility process;
• Manufacturing sequence;
• Infusion time.

A formulation can therefore present infringement risk even if its excipient system differs from the patented product, provided the administered solution contains one of the claimed combinations.

The patent does not appear, from the supplied claims, to cover oral tablets, capsules, oral suspensions, intramuscular injections, topical products, or rectal formulations. It also does not cover intravenous ibuprofen or intravenous paracetamol used separately unless the administration satisfies the claimed combination.

Manufacturing and formulation barriers

The principal technical barriers for an intravenous fixed combination are likely to involve:

• Chemical and physical stability of both active ingredients in one aqueous system;
• Control of pH and precipitation;
• Compatibility with infusion containers and administration sets;
• Sterility assurance;
• Shelf-life validation;
• Concentration and infusion-volume optimization;
• Regulatory evidence for the fixed combination.

Those barriers may be protected by separate formulation or manufacturing patents. They are not established by claims 1-4 alone. A competitor could avoid this patent while still facing separate patent or regulatory barriers relating to stability, packaging, preparation, or manufacturing.

When does US 11,446,266 lose exclusivity?

The patent issued on September 20, 2022. Its enforceable term depends on the earliest effective nonprovisional filing date, applicable patent-term adjustment, terminal disclaimers, and any patent-term extension. The patent number and supplied claims alone do not establish a definitive expiration day. [1]

For a US utility patent, the ordinary term is generally 20 years from the earliest effective US nonprovisional filing date, subject to statutory adjustments. Patent-term adjustment can extend the term for certain USPTO delays. Patent-term extension under 35 U.S.C. § 156 is generally associated with regulatory review of an approved product and must be determined from the patent and regulatory record. [2]

A practical diligence conclusion is:

• The patent has enforceable rights unless expired, disclaimed, or invalidated.
• The expected end of term is likely in the mid-2030s if the patent claims priority to an application filed around the middle of the 2010s.
• A precise expiration date should be taken from the USPTO patent-term calculation and the patent's priority chain, not inferred solely from the grant date.

What is the Orange Book status of US 11,446,266?

Patent No. 11,446,266 is not automatically an Orange Book patent merely because it claims a drug-use method. The FDA lists patents in the Orange Book when an NDA holder submits them and the listing satisfies the applicable statutory and regulatory requirements. [3]

The key commercial question is whether an FDA-approved NDA covers the specific intravenous fixed combination of ibuprofen and paracetamol and whether the NDA holder submitted this patent for listing.

If no qualifying NDA is approved and no listing has been accepted, the patent would not create a conventional Orange Book Paragraph IV pathway. A competitor could still face patent litigation through other mechanisms, including:

• A declaratory-judgment action;
• An infringement suit after commercial launch;
• A 505(b)(2) application with a patent certification strategy;
• Induced-infringement claims based on labeling or promotional conduct;
• State or contractual disputes involving licensing rights.

The Orange Book should therefore be checked separately from the USPTO patent file. The patent's existence alone does not establish an Orange Book listing.

What Paragraph IV risks exist?

A Paragraph IV challenge would be relevant only if the patent is listed against an approved reference drug and a generic or 505(b)(2) applicant relies on the applicable statutory pathway.

Potential challenge grounds include:

Challenge	Relevance to these claims
Anticipation	Prior art showing intravenous aqueous ibuprofen/paracetamol at one of the claimed doses
Obviousness	Prior art combining known intravenous ibuprofen and paracetamol with routine dose selection
Written description	Whether the patent adequately supports both dose alternatives and the claimed regimen
Enablement	Whether the disclosure enables the full scope of aqueous IV solutions and pain treatments
Indefiniteness	Meaning of "on a 6 hourly basis" and the dose language
Non-infringement	Different dose, route, patient, formulation, or dosing interval
Lack of induced infringement	Label does not direct use within the claimed method

The strongest invalidity theories would likely focus on prior disclosures of intravenous ibuprofen, intravenous paracetamol, fixed-dose analgesic use, and the claimed 1:3 dose ratio. Obviousness would require more than showing that each ingredient was separately known. The challenger would need to establish a reason to combine the teachings with a reasonable expectation of success.

Does biosimilar risk apply?

No. Ibuprofen and paracetamol are small-molecule active ingredients. Biosimilar approval under the Public Health Service Act applies to biological products, not to this fixed small-molecule combination. [4]

The relevant competitive pathways are:

• ANDA, if a suitable reference product and substitutable product structure exist;
• 505(b)(2), if the applicant relies partly on published data or an approved product but introduces a new combination, route, dosage, or formulation;
• Full NDA, if the product cannot rely on an existing approval pathway.

For an intravenous fixed combination without an approved US reference product, the 505(b)(2) or full-NDA pathway may be more commercially relevant than a conventional ANDA.

Which companies are challenging the patent?

The supplied record identifies no litigation, Paragraph IV notice, inter partes review, post-grant review, or settlement involving US 11,446,266. The patent should be searched in:

• USPTO Patent Center;
• PACER;
• PTAB proceedings;
• FDA Orange Book records;
• FDA ANDA and NDA litigation notices;
• Assignment and maintenance records.

No challenge should be treated as established without a docket, PTAB proceeding number, FDA notice, or filed certification.

How does the patent compare with competing analgesic patent estates?

Product or estate	Main protection type	Relationship to US 11,446,266
Intravenous ibuprofen products	Composition, formulation, and method patents	May be used as prior art or as separate rights against combination products
Intravenous paracetamol products	Composition, formulation, dosing, and method rights	May create separate regulatory or commercial barriers
Fixed IV ibuprofen/paracetamol products	Combination, dose, formulation, and method claims	Closest competitive category
Oral ibuprofen/paracetamol products	Tablets, capsules, and combination-use claims	Usually outside the supplied IV claims
Opioid analgesics	Composition, abuse-deterrent, method, and formulation claims	Therapeutic substitutes, not direct claim-overlap products
NSAID-acetaminophen combinations	Combination and dosing claims	Potential prior art and commercial substitutes

The patent's strongest competitive position is against a product that reproduces both claimed active-dose pairs in an aqueous intravenous product and promotes or directs use for human pain treatment.

What generic launch scenarios exist?

Scenario 1: Same-dose IV combination

A competitor launches a 150 mg/500 mg or 300 mg/1,000 mg aqueous IV product and labels it for pain. This is the highest infringement-risk scenario because it directly tracks claim 1 and may also track claims 3 or 4.

Scenario 2: Different dose ratio

A competitor changes either active ingredient amount, such as 200 mg ibuprofen/1,000 mg paracetamol. This may avoid literal infringement, but doctrine-of-equivalents issues could remain depending on the prosecution history and the significance of the numerical limitations.

Scenario 3: Separate sequential administration

A hospital administers intravenous ibuprofen and intravenous paracetamol separately rather than as one aqueous solution. This may reduce literal infringement risk because the claim requires an aqueous solution comprising the combination. The prescribing instructions, actual administration practice, and inducement evidence would matter.

Scenario 4: Non-intravenous combination

An oral or other non-IV product generally falls outside these claims.

Scenario 5: Different dosing interval

A product used every eight hours or on an as-needed basis may avoid claim 2 but would remain exposed to claim 1 if the dose, route, solution, and pain-treatment limitations are met.

How strong is the patent estate?

On the supplied claims, US 11,446,266 has moderate product-specific strength and limited platform breadth.

Its strengths are:

• Clear identification of two commercially plausible dose pairs;
• Coverage of the clinically important intravenous route;
• Broad pain indication language;
• Open-ended aqueous-composition language;
• A separate six-hour regimen claim.

Its limitations are:

• The claims do not cover all IV ibuprofen-paracetamol ratios;
• They do not claim the product as such;
• They do not recite formulation chemistry or stability features;
• They may be vulnerable to prior art involving the same actives and dose ratio;
• Claim 2's six-hour language may invite indefiniteness and construction disputes;
• The commercial value depends on an approved or commercially planned product using the claimed doses.

The patent is strongest as a blocking right against an identical or near-identical fixed IV combination. It is weaker as a barrier to alternative dose ratios, separate administration, different routes, and technically distinct formulations.

Key Takeaways

• US 11,446,266 claims intravenous treatment of human pain using either 150 mg/500 mg or 300 mg/1,000 mg ibuprofen/paracetamol.
• Claim 2 covers administration every six hours and produces a four-dose daily regimen if applied continuously.
• Claims 3 and 4 isolate the two dose alternatives but do not add formulation or dosing-interval limitations.
• The patent does not, on the supplied claims, claim a standalone vial, bag, formulation recipe, or manufacturing process.
• The closest infringement risk is an aqueous IV fixed combination using either claimed dose pair.
• Biosimilar analysis does not apply because the active ingredients are small molecules.
• Orange Book and Paragraph IV significance depends on an approved US reference product and accepted patent listing.
• The exact expiration date requires the patent's priority, terminal-disclaimer, and patent-term-adjustment records.
• No litigation, Paragraph IV challenge, PTAB proceeding, or settlement is established by the supplied information.

FAQs About US Patent 11,446,266

Does US 11,446,266 cover oral ibuprofen and paracetamol?

No. The supplied claims require intravenous administration of an aqueous solution. Oral tablets, capsules, and oral liquids are outside the literal scope of these claims.

Does the patent cover 300 mg ibuprofen with 1,000 mg acetaminophen?

Yes. Acetaminophen is the US name for paracetamol. Claim 4 specifically recites 300 mg ibuprofen in combination with 1,000 mg paracetamol.

Can a competitor avoid the patent by using separate IV products?

Potentially. Separate administration may avoid the requirement for one aqueous solution containing the claimed combination, but infringement and inducement analysis would depend on the actual product instructions and clinical use.

Is US 11,446,266 a patent on Maxigesic IV?

The claims are directed to the same general technical category as an intravenous fixed ibuprofen-paracetamol product. Product ownership, licensing, and whether a specific commercial product practices the claims require comparison of the product labeling, formulation, and patent assignment records.

Does a patent expiration automatically permit generic launch?

No. Launch timing can also depend on regulatory approval, exclusivity, Orange Book listings, patent litigation, injunctions, formulation patents, manufacturing rights, and any applicable settlement or license.

References

1. United States Patent and Trademark Office. (2022). U.S. Patent No. 11,446,266.
2. United States Code. (2023). 35 U.S.C. §§ 154, 156.
3. U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations.
4. United States Code. (2023). 42 U.S.C. § 262.

Drugs Protected by US Patent 11,446,266

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Hikma	COMBOGESIC IV	acetaminophen; ibuprofen sodium	SOLUTION;INTRAVENOUS	215320-001	Oct 17, 2023		RX	Yes	Yes						METHOD OF TREATING MILD TO MODERATE PAIN IN ADULTS
Hikma	COMBOGESIC IV	acetaminophen; ibuprofen sodium	SOLUTION;INTRAVENOUS	215320-001	Oct 17, 2023		RX	Yes	Yes						METHOD OF TREATING MODERATE TO SEVERE PAIN IN ADULTS AS AN ADJUNCT TO OPIOID ANALGESICS

International Family Members for US Patent 11,446,266

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2011324137
Brazil	112013010829
Canada	2814057
Chile	2013001250
China	103298464