US Patent 8,128,960: Triamcinolone Acetonide Ophthalmic Suspension Claims and Patent Landscape

US Patent 8,128,960 protects a narrow, preservative-free ophthalmic suspension containing 4% triamcinolone acetonide, sodium carboxymethylcellulose, polysorbate 80, chloride salts, a buffer, and water for injection. The patent is directed to a specific formulation architecture designed to control particle flocculation, viscosity, osmolality, injectability, and ocular tolerability.

The principal commercial product associated with this formulation is Triesence, a 40 mg/mL preservative-free triamcinolone acetonide injectable suspension marketed by Alcon for intraocular use.[2] The patent does not broadly cover all triamcinolone acetonide injections, all ophthalmic suspensions, or all products containing 4% triamcinolone acetonide.

What does US Patent 8,128,960 protect?

The patent's independent claim 1 requires a composition meeting every material limitation listed below:

Limitation	Required scope
Dosage form	Aqueous suspension particularly suited for injection into the eye
Preservative	No preservative
Triamcinolone acetonide	4% w/v
Particle size	Mean volume diameter of 3-10 micrometers
Suspending agent	0.5% w/v sodium carboxymethylcellulose
Surfactant	0.002-0.015% w/v polysorbate 80
Tonicity agents	One or more selected chloride salts
Osmolality	250-350 mOsm
Buffer	A buffering agent
Vehicle	Water for injection
pH	6.0-7.5
Viscosity	2-12 centipoise
Flocculation	Degree of Flocculation about 9.5 or greater
Optional component	pH-adjusting agent

The composition must also "consist essentially of" the listed ingredients. That transitional phrase generally permits additional components that do not materially alter the basic and novel characteristics of the claimed suspension. It is narrower than "comprising" and creates a potential dispute over whether an added excipient materially changes the formulation.

The patent's technical focus is the interaction between particle size, controlled flocculation, low viscosity, surfactant concentration, and physiological tonicity. The claim is not limited to a particular injection device, vial, syringe, needle gauge, administration volume, or disease indication.

How broad is claim 1 of US 8,128,960?

Claim 1 is a combination claim with substantial numerical limitations. A competing product would generally need to satisfy all required limitations for literal infringement. A formulation outside one or more critical ranges may avoid literal infringement, subject to claim construction and the doctrine of equivalents.

Key scope limitations

4% triamcinolone acetonide

The claim requires 4% w/v, equivalent to 40 mg/mL. A product containing 10 mg/mL, 20 mg/mL, 80 mg/mL, or another concentration is outside the literal concentration limitation.

The legal treatment of "4%" depends on whether the court interprets the term as an exact value or as a formulation tolerance inherent in pharmaceutical manufacturing. Batch-release specifications, assay ranges, and product labeling would be relevant.

Particle size of 3-10 micrometers

The mean volume diameter limitation is central to the claim. It is not a generic requirement that the suspension contain micronized drug. The measurement must be a mean volume diameter, not necessarily a number-average diameter, median diameter, or a different particle-size metric.

A design-around could use particles with a mean volume diameter below 3 micrometers or above 10 micrometers. Such a change may affect sedimentation, syringeability, injectability, and ocular distribution.

Sodium carboxymethylcellulose at 0.5% w/v

Claim 1 requires 0.5% w/v sodium carboxymethylcellulose. A formulation using hydroxypropyl methylcellulose, povidone, hyaluronic acid, another cellulose derivative, or a different concentration of sodium carboxymethylcellulose would not literally meet this limitation.

The claim does not broadly cover all suspending agents. It requires the specified cellulose polymer at the specified concentration.

Polysorbate 80 at 0.002-0.015% w/v

The polysorbate 80 range is unusually narrow. Claim 3 narrows the range to 0.015% w/v, the upper endpoint of claim 1.

A formulation with no polysorbate 80, or with a different surfactant such as polysorbate 20 or poloxamer 188, may avoid literal infringement. The commercial and technical value of this design-around depends on whether the replacement surfactant produces equivalent particle wetting, flocculation, and suspension stability.

Degree of Flocculation of about 9.5 or greater

This is one of the most technically significant and potentially contentious limitations. Degree of Flocculation is a physical characterization of the sedimentation state of a suspension. It normally requires a defined measurement protocol, reference state, and calculation method.

Potential claim disputes include:

The method used to determine the degree of flocculation.
The identity of the reference or fully deflocculated suspension.
Whether "about 9.5" permits values below 9.5.
Whether the value must be measured at release, during stability testing, or under a specified temperature and time condition.
Whether a batch-to-batch range is sufficient.

The patent's flocculation limitation can make infringement testing more complex than testing concentration or pH.

Viscosity of 2-12 cps

Claim 1 requires a suspension viscosity from 2 to 12 centipoise. Claims 6 and 7 narrow the upper limit to 9 cps and 8 cps, respectively.

Viscosity is condition-dependent. Temperature, shear rate, spindle, measurement geometry, settling, and test timing can change the result. A product specification using a different rheological method could generate a claim-construction dispute.

pH and osmolality

The pH range is 6.0-7.5, and osmolality must be 250-350 mOsm. These limitations target ocular tolerability and physiological compatibility.

A formulation outside either range would generally avoid literal infringement of claim 1. A product with an alternative buffer system may still infringe if it satisfies the remaining limitations and falls within the required pH and osmolality ranges.

What do dependent claims 2 through 7 add?

Claim	Added limitation	Commercial significance
2	CMC whose 2% w/v aqueous solution has viscosity of 25-50 cps at 25°C	Narrows the polymer grade and molecular-weight profile
3	Polysorbate 80 at 0.015% w/v	Covers the upper endpoint of the claim 1 surfactant range
4	0.4-0.6% sodium chloride, 0.05-0.1% potassium chloride, 0.04-0.06% calcium chloride, and 0.01-0.04% magnesium chloride	Protects a defined multi-electrolyte tonicity system
5	Sodium acetate and sodium citrate buffer	Narrows the buffering system
6	Viscosity of 2-9 cps	Provides a tighter low-viscosity embodiment
7	Viscosity of 2-8 cps	Provides the narrowest viscosity embodiment

Claim 4 is particularly important because it protects a specific combination of sodium, potassium, calcium, and magnesium chloride. Claim 5 protects a sodium acetate/sodium citrate buffer system. Claims 2, 6, and 7 provide fallback positions if broader claim 1 limitations are challenged.

What formulation is most closely associated with the patent?

The patented formulation corresponds to a preservative-free 40 mg/mL triamcinolone acetonide suspension for ocular injection. Triesence labeling identifies triamcinolone acetonide injectable suspension at 40 mg/mL and describes the product as preservative-free.[2]

The claim set is narrower than the product label in at least one important respect. The patent requires a particular combination of particle size, sodium carboxymethylcellulose, polysorbate 80, chloride salts, pH, osmolality, viscosity, and flocculation. A label may not disclose every manufacturing parameter or physical property needed to establish infringement.

What patents protect Triesence and triamcinolone acetonide ophthalmic injections?

US Patent 8,128,960 is the principal patent identified with the claimed preservative-free triamcinolone acetonide ophthalmic suspension. The patent was issued on February 28, 2012.[1]

Item	Patent or regulatory record
Patent	US 8,128,960 B2
Patent subject	Triamcinolone acetonide suspension formulation
Patent owner associated with product	Alcon-related entities
Grant date	February 28, 2012
Core product	Preservative-free 40 mg/mL triamcinolone acetonide suspension
FDA product	Triesence, NDA 022315
Dosage form	Injectable ophthalmic suspension
Statutory term	Approximately 20 years from the applicable nonprovisional filing date
Expected ordinary expiration	Approximately January 2028, subject to the patent's official term calculation
Pediatric exclusivity	No pediatric extension is identified in the cited materials
PTE	No patent-term extension is identified in the cited materials

The precise expiration date should be taken from the USPTO patent-term data and the FDA Orange Book patent table. A continuation, terminal disclaimer, patent-term adjustment, or regulatory exclusivity code can affect the operative date.[3][4]

What is the Orange Book status of US 8,128,960?

The relevant FDA product is Triesence, a prescription injectable suspension approved under NDA 022315.[2] FDA Orange Book records are the controlling source for whether US 8,128,960 is listed against the NDA, the applicable use code, and the listed expiration date.[3]

The patent claims supplied here are composition claims, not method-of-use claims. If the patent is listed in the Orange Book with a method-of-use code, that listing reflects the FDA's use-code categorization and does not change the words of the issued patent claims.

Orange Book listing has four practical consequences:

An ANDA applicant must address the listed patent.
A Paragraph IV certification can create a patent-litigation pathway.
A Paragraph III certification would defer approval until patent expiration.
A section viii statement may be relevant if the listed patent is limited to an indication that the generic applicant omits.

The composition claims create a more substantial barrier than a narrow use code if the listed patent is treated as covering the reference product's formulation.

When does US Patent 8,128,960 lose exclusivity?

The patent's ordinary term is expected to end in approximately January 2028, based on the applicable nonprovisional filing date. Patent expiration is different from FDA regulatory exclusivity.

Exclusivity type	Relevance
Patent exclusivity	Expected to run into approximately January 2028
New-drug exclusivity	Triesence received approval under an NDA; the original regulatory exclusivity period has expired
Orphan exclusivity	Not identified as the principal exclusivity for this product
Pediatric exclusivity	Not identified in the cited materials
Biosimilar exclusivity	Not applicable
Generic approval barrier	Depends on Orange Book listings, certifications, litigation, and product-specific FDA requirements

After patent expiration, an ANDA applicant still must satisfy FDA requirements for pharmaceutical equivalence, bioequivalence, sterility, injectable-product quality, and manufacturing controls. Patent expiry does not automatically establish FDA approval.

What Paragraph IV challenges and generic entry risks exist?

A generic applicant seeking to market an equivalent triamcinolone acetonide ophthalmic suspension could pursue a Paragraph IV certification against an unexpired listed patent. The applicant would need to address both patent validity and infringement.

The main Paragraph IV positions could include:

The proposed product lacks one or more required ingredients.
The product falls outside the claimed concentration or particle-size range.
The product does not meet the claimed viscosity or flocculation threshold.
The patent is obvious over earlier triamcinolone suspensions and ophthalmic formulation references.
The degree-of-flocculation limitation lacks adequate written description or enablement.
The claim is indefinite because the measurement protocol is not sufficiently defined.
The patent is not infringed because the generic formulation uses a different buffer, surfactant, suspending agent, or tonicity system.

The principal generic-entry scenarios are:

Scenario	Entry timing and risk
Paragraph III certification	Approval deferred until the listed patent expires
Paragraph IV with no litigation	FDA approval may proceed after statutory review requirements
Paragraph IV followed by suit	30-month stay may delay approval, subject to litigation developments
Non-infringing formulation	Entry depends on FDA approval and ability to avoid the claim limitations
Post-expiration launch	Patent barrier falls, but formulation and manufacturing validation remain significant

No biosimilar pathway applies because triamcinolone acetonide is a small-molecule corticosteroid. The relevant pathway is an ANDA or, depending on the proposed product and reference-product relationship, a 505(b)(2) application.

Which companies are challenging the Triesence patent?

The patent record and cited FDA materials do not establish a named Paragraph IV challenger or a reported federal litigation outcome involving US 8,128,960. A definitive challenger analysis requires current FDA Orange Book data, ANDA litigation notices, and federal court docket records.

The principal commercial parties are:

Alcon and its affiliated entities, as the product and patent stakeholders.
Generic injectable manufacturers capable of producing sterile ophthalmic suspensions.
Compounding pharmacies, which may supply triamcinolone products but do not receive the same FDA approval or patent position as an ANDA sponsor.
Developers of alternative corticosteroid delivery systems, including Clearside Biomedical and Bausch + Lomb for Xipere.

How does US 8,128,960 compare with competing corticosteroid products?

US 8,128,960 covers a suspension formulation, not the entire ophthalmic corticosteroid market.

Product or platform	Active ingredient	Delivery system	Relationship to US 8,128,960
Triesence	Triamcinolone acetonide	Injectable ophthalmic suspension	Closest commercial product
Kenalog-40	Triamcinolone acetonide	Injectable suspension, generally preserved and not the same ophthalmic formulation	Potentially outside claim scope based on formulation differences
Xipere	Triamcinolone acetonide injectable suspension	Suprachoroidal delivery system	Different delivery route and separate patent estate
Ozurdex	Dexamethasone	Biodegradable intravitreal implant	Different active ingredient and dosage form
Iluvien	Fluocinolone acetonide	Intravitreal implant	Different corticosteroid and delivery system
Yutiq	Fluocinolone acetonide	Intravitreal implant	Different active ingredient and dosage form

Xipere is a competitive corticosteroid product but is not a direct formulation substitute for the claimed aqueous 4% suspension. Its delivery route, device, dosing mechanism, and patent estate are materially different.[5]

How strong is the patent estate?

The estate is narrow in breadth but potentially strong against an exact or near-exact copy of the reference formulation.

Strengths

Multiple quantitative limitations make the claim technically specific.
The claim covers a commercial-strength 40 mg/mL formulation.
The combination of particle size, flocculation, viscosity, and osmolality may be difficult to replicate accidentally.
Dependent claims provide narrower fallback positions.
Manufacturing records and batch testing may provide direct infringement evidence.

Weaknesses and attack points

The claim contains many numerical limitations that create invalidity and noninfringement opportunities.
"About 9.5 or greater" may create a measurement and indefiniteness dispute.
The claim does not broadly cover alternative suspending agents or surfactants.
The "consists essentially of" language may limit the ability to challenge formulations containing additional excipients.
Obviousness arguments may combine known triamcinolone suspensions with conventional ophthalmic excipients and flocculation-control techniques.
The patent's commercial relevance depends on whether the FDA-listed product is materially covered by the issued claims.

The strongest enforcement position would be against a generic that deliberately matches the product's particle size, CMC grade, polysorbate concentration, electrolyte system, buffer, viscosity, and flocculation characteristics.

What manufacturing and IP barriers remain after patent expiry?

Patent expiry would remove the principal composition-claim barrier but would not eliminate technical entry barriers.

A generic manufacturer would need to control:

Sterile micronization or particle-size classification.
Uniform drug distribution in a high-strength suspension.
Sedimentation and redispersion behavior.
Flocculation under storage and agitation.
Low-viscosity injection performance.
Extractables and leachables from the container-closure system.
Sterility assurance and particulate limits.
Stability across the labeled shelf life.
Batch-to-batch control of mean volume diameter and rheology.
Bioequivalence or other FDA-supported equivalence requirements.

These manufacturing requirements can limit the number of viable entrants even after the patent expires.

What licensing deals affect US 8,128,960?

The patent and FDA product records identify the patent and product ownership relationship but do not identify a separate publicly disclosed license specifically covering US 8,128,960. The principal commercial exposure is therefore associated with Alcon's product franchise rather than a documented third-party licensing arrangement.

Key Takeaways

US 8,128,960 is a narrow composition patent for a preservative-free 4% triamcinolone acetonide ophthalmic suspension.
Claim 1 requires all major formulation elements, including 0.5% sodium carboxymethylcellulose, 0.002-0.015% polysorbate 80, defined chloride salts, pH, osmolality, viscosity, particle size, and flocculation.
Claims 2-7 provide narrower protection for the CMC grade, polysorbate concentration, electrolyte system, buffer, and viscosity.
The patent is most relevant to Triesence and is not a broad patent on triamcinolone acetonide injections.
The expected ordinary patent term runs to approximately January 2028, subject to official term data.
Generic applicants could challenge through Paragraph IV or design around the formulation.
Biosimilar risk is irrelevant because triamcinolone acetonide is a small molecule.
The principal technical entry barriers are sterile micronization, suspension stability, flocculation control, rheology, and injectable-product manufacturing.

FAQs About US Patent 8,128,960

Does US 8,128,960 cover Kenalog-40?

Not automatically. Kenalog-40 would need to satisfy every material limitation of the asserted claim, including the preservative-free requirement, 4% concentration, sodium carboxymethylcellulose concentration, polysorbate 80 range, particle-size range, viscosity, osmolality, pH, and flocculation value.

Can a generic avoid US 8,128,960 by changing the surfactant?

Potentially. Replacing polysorbate 80 with another surfactant may avoid literal infringement of claim 1, although the product would still require FDA support for stability, injectability, sterility, and equivalence.

Is US 8,128,960 a method-of-use patent?

The claims supplied are composition claims. They do not claim administering triamcinolone acetonide to treat uveitis, sympathetic ophthalmia, or temporal arteritis.

Does Xipere infringe US 8,128,960?

Xipere uses triamcinolone acetonide but employs a different suprachoroidal delivery system and a separate product design. Infringement would depend on whether its formulation satisfies every limitation of the asserted claim, not merely on its use of the same active ingredient.

What is the main invalidity risk for US 8,128,960?

The principal risks are obviousness based on prior-art ophthalmic suspensions, inadequate support for the precise flocculation and particle-size limitations, indefiniteness concerning measurement methods, and noninfringement based on differences in formulation composition or physical properties.

References

U.S. Patent No. 8,128,960 B2. (2012). Triamcinolone acetonide suspension formulation. United States Patent and Trademark Office.
U.S. Food and Drug Administration. (2007). Triesence (triamcinolone acetonide injectable suspension) prescribing information. Alcon Laboratories, Inc.
U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Food and Drug Administration. (2018). ANDA submissions: Amendments and requests for final approval to tentatively approved ANDAs.
U.S. Food and Drug Administration. (2021). Xipere (triamcinolone acetonide injectable suspension) prescribing information. Bausch + Lomb and Clearside Biomedical.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Harrow Eye	TRIESENCE	triamcinolone acetonide	INJECTABLE;INTRAVITREAL	022048-001	Nov 29, 2007		RX	Yes	Yes	8,128,960	⤷ 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
Argentina	070824	⤷ Start Trial
Australia	2009223649	⤷ Start Trial
Brazil	PI0909630	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,128,960

Which drugs does patent 8,128,960 protect, and when does it expire?

Summary for Patent: 8,128,960