US Patent 11,253,478: Scope, Claims, Expiration, and Meloxicam Patent Landscape

US Patent 11,253,478 protects a specific injectable nanoparticulate meloxicam formulation that combines sub-400 nm meloxicam particles, a non-crosslinked surface stabilizer, sucrose as an aggregation-reduction agent, controlled large-particle counts, and three-month stability at 25°C. The patent is closely aligned with the formulation used in Anjeso, the intravenous meloxicam product marketed by Baudax Bio. Its composition claims create the principal product-level barrier to generic injectable meloxicam products that use the same nanoparticle and excipient architecture. [1][2]

What does US Patent 11,253,478 protect?

The patent protects both the composition and specified methods of administering it to humans. Claim 1 is the controlling independent composition claim.

Claim element	Required limitation
Active ingredient	Meloxicam is the only active agent
Meloxicam concentration	About 2.5% to about 5% w/w
Particle size	Effective average particle size below about 400 nm
Surface stabilizer	About 0.5% to about 1.625% w/w of at least one non-crosslinked surface stabilizer
Aggregation-reduction agent	About 1.25% to about 20% w/w
Aggregation-reduction agent identity	Consists of sucrose
Vehicle	Water
Oversized particles	No more than 3,000 particles above 10 micrometers and no more than 300 active meloxicam particles above 25 micrometers in a nominal 25 mL volume
Stability	Stable and suitable for injection after at least three months at 25°C

A product must satisfy every limitation of claim 1 to infringe literally. The claim is narrower than a general nanoparticulate meloxicam claim because it requires a particular concentration range, sucrose, a water-based injectable composition, particle-count limits, and a defined stability condition.

The claim does not require a particular injection route. The composition can fall within claim 1 even if the labeled route is intravenous, intramuscular, or subcutaneous, provided the formulation satisfies the remaining limitations.

How do dependent claims 2 through 11 narrow the patent scope?

Claims 2 and 3 narrow the particle-size requirement:

Claim 2: effective average size below about 300 nm.
Claim 3: effective average size below about 200 nm.

These claims provide progressively narrower protection. A formulation with a median or average particle size of 150 nm could fall within claims 1, 2, and 3, assuming the other limitations are met. The relevant measurement method and the patent’s definition of “effective average particle size” would matter in litigation.

Surface-stabilizer claims

Claim 4 covers broad classes of stabilizers, including nonionic, ionic, anionic, cationic, and zwitterionic stabilizers.

Claim 5 contains an extensive Markush list. It expressly identifies numerous stabilizer families, including:

Polyvinylpyrrolidone, or PVP
Sodium deoxycholate-related stabilizing systems
Poloxamers and poloxamines
Polyethylene glycols
Cellulosic polymers
Phospholipids
Surfactants
Quaternary ammonium compounds
Sodium lauryl sulfate
Gelatin, casein, and phosphatides
Cationic polymers and polysaccharides

Claim 5 is commercially important because it limits design-around value from changing only the identity of the surface stabilizer. A competing product using a listed stabilizer may remain within the claim if it also satisfies the concentration, particle-size, sucrose, particle-count, and stability limitations.

Claim 6 specifies PVP. Claim 7 further specifies approximately 0.5% w/w PVP.

Claim 8 identifies sodium deoxycholate. Claim 9 specifies approximately 0.25% w/w sodium deoxycholate.

There is a drafting issue in the relationship between claims 1, 8, and 9. Claim 1 requires approximately 0.5% to approximately 1.625% w/w of at least one surface stabilizer, while claim 9 identifies a composition with approximately 0.25% sodium deoxycholate. Claim 11 resolves this issue for a dual-stabilizer formulation by reciting approximately 0.5% PVP and approximately 0.25% sodium deoxycholate together. The combined amount is approximately 0.75% w/w and fits within claim 1’s total stabilizer range.

Large-particle control claims

Claim 10 narrows claim 1 to fewer than approximately 1,000 active-agent particles larger than approximately 10 micrometers.

This limitation is significant for injectable products. It moves the claim beyond chemical composition and into particulate quality control. A generic manufacturer could use the same active ingredient and excipients but avoid claim 10 by failing to meet the narrower particle-count threshold. That strategy would not avoid claim 1 if the product still met claim 1’s less restrictive limits.

Product-aligned formulation claims

Claim 11 covers a formulation containing:

Approximately 0.5% w/w PVP
Approximately 0.25% w/w sodium deoxycholate
Approximately 5% w/w sucrose
Nanoparticulate meloxicam within claim 1’s particle and stability limitations

Claim 14 covers a similar formulation with approximately 0.75% PVP and approximately 0.25% sodium deoxycholate, together with approximately 5% sucrose.

These claims are the most commercially relevant claims for a product using the same excipient system as Anjeso. They provide narrower, formulation-specific positions that may be easier to compare against a marketed product than the broad Markush language in claim 5.

What do claims 12 and 13 cover?

Claims 12 and 13 are method-of-use claims.

Claim	Covered administration
Claim 12	Intravenous, intramuscular, or subcutaneous injection into a human
Claim 13	Intravenous injection into a human

Claim 13 is especially relevant to Anjeso because the approved product is administered intravenously. The method claims require use of the claimed composition in a human. They do not independently protect oral meloxicam, topical meloxicam, conventional meloxicam suspensions, or formulations containing another active agent.

A generic applicant could face both composition-claim and method-claim exposure if its proposed injectable product has the same formulation and its labeling directs intravenous administration.

How closely does the patent cover Anjeso?

Anjeso is an injectable meloxicam product approved by the FDA for the management of moderate-to-severe pain in adults when an intravenous NSAID is appropriate. The product contains 30 mg meloxicam per 1 mL, equivalent to approximately 3% w/w or w/v depending on the formulation basis used for comparison. Its formulation uses nanoparticulate meloxicam with PVP, sodium deoxycholate, sucrose, and water. [2]

The core Anjeso formulation aligns with the principal claim architecture:

Anjeso-related characteristic	Relevance to US 11,253,478
Meloxicam as the sole active ingredient	Matches claim 1
Approximately 3% meloxicam concentration	Within the 2.5% to 5% range
Nanoparticulate meloxicam	Matches claim 1
PVP stabilizer	Specifically identified in claims 5 through 7 and 11
Sodium deoxycholate	Specifically identified in claims 8, 9, 11, and 14
Sucrose	Required aggregation-reduction agent under claim 1
Intravenous administration	Covered by claims 12 and 13
Injectable stability and particulate control	Express limitations of claim 1

A formulation that copies the commercial excipient system but changes particle size, concentration, or particle-count specifications could still face infringement risk under claim 1 or other dependent claims. A product that uses a materially different stabilizer system or aggregation-control strategy would have a stronger design-around position, subject to the literal scope of the broad stabilizer language and potential doctrine-of-equivalents arguments.

What is the FDA and Orange Book status of US 11,253,478?

Anjeso was approved under NDA 211816. The FDA approved the product in February 2020 for intravenous use in adults with moderate-to-severe pain. [2]

US Patent 11,253,478 is associated with the Anjeso injectable meloxicam product and is listed in the FDA Orange Book patent framework for the approved drug product. The patent was issued on February 22, 2022. The relevant patent term is reported to extend to February 12, 2035, subject to statutory adjustments and any applicable terminal-disclaimer or patent-term calculations reflected in official records. [1][3]

Regulatory or patent event	Date
FDA approval of Anjeso	February 2020
US Patent 11,253,478 issued	February 22, 2022
Reported patent expiration	February 12, 2035
Earliest practical generic-entry target	After applicable exclusivity and patent barriers are resolved

The Orange Book listing does not itself establish infringement. It gives an ANDA applicant a regulatory notice of listed patents and determines whether a Paragraph IV certification may trigger patent litigation and a potential 30-month FDA approval stay.

When does injectable meloxicam lose exclusivity?

The principal patent-based loss-of-exclusivity date associated with the Anjeso formulation is February 12, 2035, based on the reported term for the relevant patent estate. FDA regulatory exclusivity and patent protection are separate.

A generic applicant may file an ANDA before patent expiration. It must certify that each listed patent is not infringed, is invalid, or will not be infringed by the proposed product. A Paragraph IV certification can lead to litigation under the Hatch-Waxman Act. If the patent holder files suit within the statutory period, FDA approval may be stayed for up to 30 months, subject to court action and statutory exceptions. [4]

The first substantially complete Paragraph IV filer may qualify for 180-day generic exclusivity if the statutory requirements are met. That status depends on the filing history and forfeiture provisions, not merely on being the first company to announce a challenge.

Which companies are challenging the Anjeso patent estate?

The public record must be evaluated through FDA ANDA notices, federal court dockets, and company disclosures. A Paragraph IV certification is not the same as an approved generic, commercial launch, or final invalidity judgment.

The relevant competitive set includes generic injectable manufacturers with capabilities in:

Sterile injectable suspension manufacturing
Nanoparticle milling or precipitation
Sub-400 nm particle-size control
Large-particle enumeration
Low-bioburden and aseptic processing
Stability testing for injectable suspensions

Potential ANDA entrants must address both regulatory and technical barriers. The product is not a conventional aqueous meloxicam solution. A generic applicant must reproduce or replace the nanoparticle performance profile while satisfying injectable particulate standards and demonstrating bioequivalence or another FDA-accepted pathway.

No biosimilar pathway applies. Meloxicam is a small-molecule NSAID, so competitive entry would proceed through an ANDA or, depending on the product and formulation differences, a 505(b)(2) application rather than a biosimilar application.

What Paragraph IV risks exist for US 11,253,478?

A Paragraph IV challenge could target several claim vulnerabilities.

Particle-size indefiniteness or measurement disputes

The claims use “effective average particle size,” “about,” and particle-count thresholds. Litigation could focus on:

The analytical method used to measure effective average size
Whether intensity-weighted or volume-weighted measurements apply
Sampling and dilution procedures
Whether oversized particles are active meloxicam particles or formulation particles
The statistical significance of measurements from a 25 mL nominal volume

The particle-count limitations may require validated methods capable of detecting and classifying rare particles above 10 and 25 micrometers.

Written-description and enablement issues

Claim 5 lists a very large number of stabilizers. A challenger could argue that the patent does not adequately support the full genus across all listed stabilizers, concentrations, particle sizes, sucrose levels, and stability outcomes.

The patent holder would likely rely on examples, formulation guidance, and the predictability of nanoparticle stabilization technology to defend the claims.

Indefiniteness and claim-construction issues

Terms that could receive scrutiny include:

“About”
“Flake-like aggregation reducing agent”
“Stable”
“Suitable for injection”
“Effective average particle size”
“Active meloxicam particles”

The patent’s specification and prosecution history would control how these terms are construed. Claim 9’s approximately 0.25% sodium deoxycholate limitation presents a separate dependency and consistency issue, although claim 11 provides a stronger dual-stabilizer formulation position.

Obviousness

A challenger could combine prior art relating to:

Nanocrystalline NSAIDs
Injectable meloxicam
PVP or bile-salt stabilization
Sucrose in injectable formulations
Reduction of aggregation in nanoparticle suspensions
Injectable particle-count standards

The strongest validity defense would depend on evidence that the claimed combination produced unexpected stability, injectability, pharmacokinetic, safety, or particle-distribution results.

How strong is the patent estate for injectable meloxicam?

The estate is strongest against a product that copies the commercial formulation and weakest against a materially different injectable design.

Risk category	Assessment	Reason
Same nanoparticle size range	High	Claim 1 reaches below 400 nm
Same PVP and sodium deoxycholate system	High	Expressly covered by claims 5 through 11 and 14
Same sucrose-based aggregation control	High	Sucrose is required by claim 1
Different stabilizer but same other parameters	Moderate to high	Claim 5 contains broad stabilizer classes
Larger particles above 400 nm	Lower under claims 1 through 3	May avoid the express particle-size limitation
Non-sucrose aggregation-control agent	Lower	Claim 1 requires sucrose
Oral or topical meloxicam	None under claims 12 and 13	Claims are directed to injectable compositions and human injection
Combination product with another active agent	Lower under claim 1	Claim 1 requires meloxicam to be the only active agent
Subcutaneous or intramuscular product	Composition risk remains	Claim 12 covers those routes
Alternative dosage form	Generally lower	The claims require an injectable composition

The claims create a formulation fence rather than complete field exclusivity over meloxicam. They do not block all meloxicam products. They target a defined injectable nanoparticle platform.

What manufacturing and intellectual-property barriers affect generic entry?

The technical barrier may be as significant as the legal barrier. A competing manufacturer must control:

Meloxicam particle-size distribution at the submicron scale.
Adsorption of the selected surface stabilizer.
Prevention of aggregation during storage.
Low levels of particles above injectable-size thresholds.
Sterility and aseptic processing.
Container-closure compatibility.
Physical stability through the labeled shelf life.
Reproducibility at commercial batch scale.

A design-around that replaces sucrose may avoid the express claim 1 limitation, but it must still deliver acceptable stability and injectability. Replacing PVP or sodium deoxycholate may avoid narrower claims but could remain within the broad stabilizer genus. Increasing particle size may reduce patent risk but could alter dissolution, exposure, tolerability, or clinical performance.

How does US 11,253,478 compare with conventional meloxicam patents?

Patent category	Main protected subject matter	Relevance to Anjeso competition
Conventional meloxicam composition patents	Chemical forms, salts, polymorphs, or oral formulations	Usually limited relevance to nanoparticulate injection
Nanoparticle platform patents	Particle-size reduction and stabilizer systems	Potentially relevant depending on term and claim scope
US 11,253,478	Meloxicam nanoparticle injectable composition with sucrose and particle controls	Directly relevant
Method-of-use patents	Treatment of pain or inflammatory conditions	May affect labeling and induced-infringement analysis
Manufacturing patents	Milling, precipitation, drying, or sterile processing	May create separate process barriers
Regulatory exclusivity	NDA-based FDA protections	Separate from patent infringement

The commercial patent risk is concentrated in the combination of formulation claims, not in meloxicam as a molecule. Meloxicam itself is an established NSAID with extensive prior art.

What generic launch scenarios exist?

Launch after patent expiry

This is the lowest litigation-risk scenario. An applicant can develop and file before expiry, then launch after February 12, 2035, assuming FDA approval and no additional unexpired patents or regulatory barriers.

Paragraph IV launch

A challenger could file an ANDA with a Paragraph IV certification against US 11,253,478 and related listed patents. The company would need a non-infringement, invalidity, or unenforceability position. Litigation could delay approval for up to 30 months if timely filed.

Formulation design-around

A manufacturer could avoid one or more claim limitations by using:

A non-sucrose aggregation-reduction agent
A different particle-size distribution
A different stabilizer architecture
A different concentration range
A formulation containing another active agent, although this creates separate regulatory and clinical complications

This route could reduce patent exposure but may require a 505(b)(2) strategy rather than a straightforward ANDA if the product is not pharmaceutically equivalent to the reference product.

Authorized or licensed entry

A license, settlement, or authorized-generic arrangement could permit earlier market access. The economics would depend on royalty rates, launch timing, supply obligations, and whether the arrangement limits the number of entrants.

Key Takeaways

US Patent 11,253,478 covers a specific injectable nanoparticulate meloxicam formulation.
Claim 1 requires 2.5% to 5% meloxicam, particles below 400 nm, a qualifying surface stabilizer, sucrose, water, controlled large-particle counts, and three-month stability at 25°C.
Claims 6, 7, 8, 9, 11, and 14 are directed to PVP, sodium deoxycholate, and combinations that closely track the Anjeso formulation.
Claims 12 and 13 cover human administration by intravenous, intramuscular, and subcutaneous injection, with claim 13 limited to intravenous use.
The reported patent expiration date is February 12, 2035.
The patent does not cover all meloxicam products, oral formulations, or non-injectable dosage forms.
Generic risk is highest for a product that copies the nanoparticle, PVP, sodium deoxycholate, sucrose, concentration, and stability profile.
No biosimilar pathway applies because meloxicam is a small molecule.
Particle-size measurement, oversized-particle enumeration, claim construction, written description, enablement, and obviousness are the principal litigation pressure points.

FAQs

Can a generic company avoid US 11,253,478 by using a meloxicam solution?

Yes, if the product is genuinely a solution rather than a nanoparticulate suspension and does not meet the claim’s particle-size and particle-count limitations. It would still need to satisfy FDA requirements for the applicable regulatory pathway.

Does using sodium chloride instead of sucrose avoid the patent?

It may avoid claim 1’s express sucrose limitation, but the complete formulation and related patent claims must be assessed. A different excipient does not automatically eliminate infringement under every claim or related patent.

Does claim 11 cover the marketed 30 mg/mL Anjeso product?

Claim 11 is directed to approximately 0.5% PVP, approximately 0.25% sodium deoxycholate, approximately 5% sucrose, and the claim 1 nanoparticle and stability limitations. A product with those characteristics is within the principal commercial risk zone.

Can an ANDA applicant omit intravenous use from its label?

Label modification may affect method-of-use infringement, but it does not avoid composition claims. If the formulation itself falls within claims 1 or 11, removing an administration route from labeling may not eliminate product-claim exposure.

Are injectable meloxicam products subject to biosimilar competition?

No. Meloxicam is a small-molecule active pharmaceutical ingredient. Competition would generally involve an ANDA or 505(b)(2) application, not a biosimilar application.

References

United States Patent and Trademark Office. (2022). Injectable nanoparticulate meloxicam compositions, U.S. Patent No. 11,253,478.
U.S. Food and Drug Administration. (2020). Anjeso (meloxicam) injection prescribing information. Baudax Bio, Inc.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
Drug Price Competition and Patent Term Restoration Act of 1984, 21 U.S.C. § 355(j).

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Baudax	ANJESO	meloxicam	SOLUTION;INTRAVENOUS	210583-001	Feb 20, 2020		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial	Y			MANAGEMENT OF MODERATE-TO-SEVERE PAIN BY INJECTION	⤷ 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
Australia	2010254180	⤷ Start Trial
Canada	2763456	⤷ Start Trial
European Patent Office	2435027	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 11,253,478

Which drugs does patent 11,253,478 protect, and when does it expire?

Summary for Patent: 11,253,478