US Patent 8,354,409: Scope, Claim Analysis, Expiration, Orange Book Status, and Generic Risk

US Patent 8,354,409 covers a fixed ophthalmic combination of brimonidine and timolol at the commercial Combigan concentrations of 0.2% and 0.5%. Its strongest protection is the composition claim requiring both active ingredients, sterility, topical ophthalmic suitability, and the specified concentrations. The patent also includes narrower formulation claims and method-of-use claims directed to twice-daily treatment and reduced adverse-event incidence. The patent was assigned to Allergan, Inc., the developer of Combigan, and issued on January 15, 2013.[1]

The principal commercial risk is an exact or substantially identical generic formulation. A product using different concentrations, a nonsterile formulation, separate containers, or a different dosing regimen may avoid literal infringement of some claims, although other patents, regulatory requirements, or equivalents-based infringement theories may remain relevant.

What drug does US Patent 8,354,409 protect?

US Patent 8,354,409 protects a fixed-dose ophthalmic composition containing:

Element	Claimed requirement
Alpha-2 adrenergic agonist	Brimonidine
Beta blocker	Timolol
Brimonidine concentration	0.2% w/v
Timolol concentration	0.5% w/v
Dosage form	Single pharmaceutical composition
Sterility	Required
Administration	Topical ophthalmic use
Commercial product association	Combigan ophthalmic solution

Combigan contains brimonidine tartrate equivalent to brimonidine 0.2% and timolol maleate equivalent to timolol 0.5%. The FDA-approved product is indicated for lowering elevated intraocular pressure in patients with glaucoma or ocular hypertension who require adjunctive or replacement therapy.[2]

The patent does not broadly cover every brimonidine-timolol combination. The independent composition claim is concentration-specific and requires the two agents to be present in one composition.

What are the independent claims of US 8,354,409?

The patent has two principal independent claim categories.

Claim 1: Fixed-dose ophthalmic composition

Claim 1 requires a composition comprising:

brimonidine at 0.2% w/v;
timolol at 0.5% w/v;
a single composition;
sterility; and
suitability for topical ophthalmic administration.

The use of “comprising” makes the claim open-ended. A competing product may contain additional excipients, preservatives, buffers, viscosity modifiers, tonicity agents, or other inactive ingredients and still fall within claim 1 if all required elements are present.

The claim is not limited to brimonidine tartrate or timolol maleate. Claims 4 through 7 separately identify salt and free-base forms. This structure indicates that claim 1 is intended to reach the active ingredients generally, while the dependent claims provide narrower fallback positions.

Claim 10: Method of reducing intraocular pressure

Claim 10 covers a method of reducing intraocular pressure in a patient with elevated intraocular pressure or glaucoma by administering the composition of claim 1 to an eye.

Because claim 10 depends on claim 1, the method requires use of the claimed 0.2%/0.5% sterile fixed combination. It is not a general claim to treating glaucoma with brimonidine and timolol in any formulation.

How broad is claim 1 of US Patent 8,354,409?

Claim 1 is commercially significant but technically narrow.

A product would generally need to satisfy all of the following limitations for literal infringement:

Limitation	Scope
Brimonidine	Must be present
Timolol	Must be present
Concentration	0.2% w/v brimonidine and 0.5% w/v timolol
Combination	Both agents must be in one composition
Sterility	Product must be sterile
Route and dosage form	Suitable for topical ophthalmic use

The claim can potentially cover different salt forms and excipient systems because it does not expressly require phosphate buffer, benzalkonium chloride, or a particular pH. Claims 2 through 9 narrow the scope by adding those features.

A generic product with the same labeled strengths and ophthalmic solution format would face a high literal-infringement risk under claim 1, assuming the product is sterile and contains both drugs in the same container.

What formulations are protected by US Patent 8,354,409?

The dependent formulation claims cover specific versions of the fixed combination.

Claim	Additional limitation
2	Phosphate buffer
3	About 0.005% benzalkonium chloride, dependent on claim 2
4	Brimonidine tartrate
5	Brimonidine free base
6	Timolol maleate
7	Timolol free base
8	pH of about 6.9
9	Carboxymethyl cellulose at about 0.01% to about 2% w/v

Phosphate-buffered formulations

Claim 2 requires a phosphate buffer. Claim 3 adds approximately 0.005% benzalkonium chloride to the phosphate-buffered formulation.

These claims are narrower than claim 1. A competing product without phosphate buffer may still infringe claim 1 but would not literally infringe claim 2.

Benzalkonium chloride

Claim 3 is directed to a formulation containing approximately 0.005% benzalkonium chloride. The use of “about” creates a range rather than an exact numerical requirement. The scope would depend on claim construction, specification support, analytical measurement, and the product’s actual concentration.

Benzalkonium chloride is a common ophthalmic preservative. Its presence alone does not establish infringement because claim 3 also requires the limitations inherited from claims 1 and 2.

pH limitation

Claim 8 requires a pH of about 6.9. A product outside the construction of “about 6.9” may avoid literal infringement of claim 8 while remaining exposed under claim 1.

Carboxymethyl cellulose

Claim 9 covers the addition of carboxymethyl cellulose at about 0.01% to about 2% w/v. This claim is relevant to viscosity-modified or comfort-enhanced ophthalmic formulations. It does not require phosphate buffer or benzalkonium chloride unless those limitations are introduced through another dependent claim structure.

What method-of-use protection does US Patent 8,354,409 provide?

Claims 10 through 21 cover treatment methods and comparative adverse-event outcomes.

Claim	Claimed treatment limitation
10	Reducing intraocular pressure in glaucoma or elevated intraocular pressure
11	Administration two times daily
12	Lower conjunctival hyperemia incidence
13	Lower visual disturbance incidence
14	Lower epiphora incidence
15	Lower oral dryness incidence
16	Lower eye pruritus incidence
17	Lower allergic conjunctivitis incidence
18	Lower asthenia incidence
19	Lower foreign-body sensation incidence
20	Lower conjunctival folliculosis incidence
21	Lower somnolence incidence

Each adverse-event claim compares treatment with the fixed combination against brimonidine administered three times daily without concurrent timolol.

Strength of the comparative safety claims

The comparative limitations create both enforcement value and litigation risk.

For infringement, the patent owner would need to show more than administration of the product. The claimed lower incidence must be tied to the claimed treatment regimen and comparison. Evidence could include:

FDA labeling;
clinical-study reports;
product instructions;
promotional materials;
clinical trial data;
prescribing patterns;
statistical evidence concerning the relevant adverse event.

A generic applicant that labels its product for the same twice-daily indication may face method-of-use exposure even if it does not promote every comparative safety benefit. The practical issue is whether the proposed label, instructions, or foreseeable use would induce performance of the claimed method.

The safety claims may be more vulnerable than the composition claim to arguments involving indefiniteness, lack of written description, enablement, anticipation, or insufficient proof of a statistically meaningful comparison. Those issues depend on the patent specification, prosecution history, cited prior art, and any court claim-construction record.

When does US Patent 8,354,409 lose exclusivity?

US Patent 8,354,409 issued January 15, 2013. Its listed patent term extends into 2029. Public Orange Book records identify the patent in connection with Combigan and report a 2029 expiration date.[3]

Milestone	Date
Patent issue	January 15, 2013
Product association	Combigan, NDA 021398
Listed Orange Book term	2029
Earlier foundational Combigan patent	US 6,641,834
Earlier patent’s reported term	2022

The precise enforceable end date should be determined from the USPTO patent-term record, including any patent-term adjustment, patent-term extension, terminal disclaimer, or other adjustment. For market planning, the material point is that US 8,354,409 extends beyond the expiration of the earlier foundational patent and was positioned as a later barrier to generic fixed-combination entry.

What is the Orange Book status of US 8,354,409?

The patent is associated with Combigan, brimonidine tartrate/timolol maleate ophthalmic solution, under FDA NDA 021398.[2,3]

An Orange Book listing does not itself establish validity or infringement. It gives an NDA holder a statutory basis to notify FDA of patent rights relevant to an approved drug. The listing can delay approval of an ANDA depending on the type of certification submitted and the timing of litigation.

The relevant regulatory pathways are:

ANDA certification	Commercial consequence
Paragraph I	No patent information listed
Paragraph II	Listed patent has expired
Paragraph III	Applicant will wait until patent expiration
Paragraph IV	Applicant asserts the patent is invalid, unenforceable, or not infringed

A Paragraph IV notice concerning US 8,354,409 could trigger patent litigation under the Hatch-Waxman Act. A timely suit by the NDA holder can create a statutory stay of FDA approval, generally up to 30 months, subject to statutory exceptions and court developments.[4]

Which companies are challenging the Combigan patent estate?

The supplied patent claims do not identify a particular challenger, lawsuit, settlement, or ANDA filer. The patent document itself cannot establish the current identity of all Paragraph IV challengers or the status of related litigation.

The principal competitive group consists of generic ophthalmic manufacturers capable of filing an ANDA for brimonidine tartrate/timolol ophthalmic solution. Potential commercial entrants must address:

the 0.2%/0.5% fixed-dose formulation;
sterility and container-closure requirements;
preservative concentration;
bioequivalence or comparative clinical requirements;
Orange Book patent certifications;
method-of-use labeling;
manufacturing controls for ophthalmic products.

A complete challenger-by-challenger litigation table cannot be accurately derived from the claims supplied.

What generic entry risks exist for Combigan?

The generic entry risk is highest for a product that matches the commercial formulation and labeling.

High-risk launch profile

A generic product is exposed if it has:

brimonidine at 0.2% w/v;
timolol at 0.5% w/v;
both actives in one sterile ophthalmic composition;
topical ocular administration;
twice-daily dosing;
a glaucoma or ocular-hypertension indication.

That profile maps directly onto claims 1, 10, and 11.

Lower-risk design-around profiles

Potential design-around concepts include:

Design choice	Potential effect
Separate bottles	May avoid the “single composition” limitation
Different active concentrations	May avoid literal infringement of claim 1
Non-phosphate buffer	May avoid claim 2
No benzalkonium chloride	May avoid claim 3
Different pH	May avoid claim 8
No carboxymethyl cellulose	May avoid claim 9
Different dosing schedule	May avoid claim 11 and some method claims
Label carve-out	May reduce induced-infringement exposure for method claims

These strategies do not automatically eliminate infringement risk. A product still must satisfy FDA requirements, and a court may consider equivalents, the prosecution history, and the product’s actual composition.

How does US 8,354,409 compare with the earlier Combigan patent estate?

US 8,354,409 is best understood as a later patent layer around the same commercial product.

Issue	Earlier Combigan patent	US 8,354,409
Primary focus	Foundational brimonidine-timolol combination	Fixed concentrations, formulation variants, dosing, and safety outcomes
Commercial product	Combigan	Combigan
Composition protection	Broad combination protection may apply	0.2%/0.5%, sterile topical ophthalmic composition
Method protection	May cover therapeutic use	IOP reduction, twice-daily use, comparative adverse-event outcomes
Reported expiry	2022	2029
Generic significance	Earlier barrier	Later listed barrier

The later patent’s commercial value depends on whether the earlier patent expired before the later patent became the operative barrier, whether the later patent survived any validity challenge, and whether an ANDA applicant could launch with a noninfringing formulation or carved-out labeling.

How strong is the patent estate for the brimonidine-timolol combination?

The patent estate has moderate-to-strong commercial blocking value for an exact Combigan substitute, but its strength is uneven across claim categories.

Strongest elements

The strongest practical protection is claim 1 because it combines:

a recognizable commercial product;
exact active concentrations;
a single composition;
sterility; and
topical ophthalmic use.

These features are easy to compare against a generic product’s chemistry, manufacturing information, and label.

Intermediate elements

The dependent formulation claims add useful barriers where the generic product uses the same buffer, preservative, pH, or viscosity modifier. Their narrower scope also creates more design-around opportunities.

More contestable elements

The comparative safety claims may be harder to enforce because they require proof of a lower incidence of named adverse events relative to a specified brimonidine regimen. The claims also raise questions concerning:

the meaning of “lower incidence”;
the relevant patient population;
statistical significance;
whether the comparison is inherent or expressly practiced;
whether the generic label induces the claimed comparison.

What manufacturing and intellectual-property barriers affect generic entry?

The main non-patent barriers are sterile ophthalmic manufacturing and product equivalence.

A generic manufacturer must establish control over:

aseptic processing;
preservative content;
pH and osmolality;
container-closure integrity;
particulate and microbial limits;
active-ingredient assay;
degradation products;
drop size and delivery performance;
stability throughout shelf life.

The fixed combination also creates formulation-development constraints. Brimonidine and timolol must remain chemically and physically stable in a sterile aqueous vehicle while meeting tolerability and preservative requirements.

These manufacturing barriers do not extend patent life, but they can affect the timing, cost, and reliability of generic development.

Does biosimilar risk apply to Combigan?

No. Combigan is a small-molecule ophthalmic drug, not a biologic. The relevant competitive pathway is an abbreviated new drug application under section 505(j) of the Federal Food, Drug, and Cosmetic Act, not a biosimilar application under section 351(k) of the Public Health Service Act.

The relevant entrants are generic manufacturers, including ophthalmic-product companies, rather than biosimilar developers.

What is the revenue exposure from US 8,354,409?

AbbVie and its predecessor Allergan have not generally reported Combigan revenue as a separately disclosed public line item in the principal company-level financial reporting used by investors. The product is generally included within broader pharmaceutical or eye-care reporting categories.

The patent’s commercial exposure is therefore best assessed through:

Combigan prescription volume;
net sales disclosed in portfolio materials;
generic launch timing;
payer substitution;
price erosion after ANDA approval;
share captured by authorized or independent generics.

For a generic entrant, the most valuable opportunity is a same-strength, same-container fixed combination that can substitute directly for Combigan. For the branded company, the critical exposure begins when FDA approval and litigation outcomes permit commercial substitution, not merely when the patent approaches expiration.

Key Takeaways

US 8,354,409 covers a sterile topical ophthalmic composition containing brimonidine 0.2% w/v and timolol 0.5% w/v in a single composition.
Claim 1 is the principal commercial claim and maps closely to Combigan.
Claims 2 through 9 protect narrower buffer, preservative, salt-form, pH, and viscosity-modified formulations.
Claims 10 and 11 cover intraocular-pressure reduction and twice-daily administration.
Claims 12 through 21 add comparative reductions in specified adverse events and may be more difficult to enforce than the composition claim.
The patent issued January 15, 2013 and is listed with a 2029 expiration period for Combigan.
The principal generic pathway is an ANDA with Paragraph II, III, or IV certification, not a biosimilar application.
Exact fixed-combination generics face the highest infringement risk.
Separate-container products, different strengths, altered excipients, and label carve-outs are the principal design-around strategies.
The supplied record does not establish a complete current list of Paragraph IV challengers, lawsuits, or settlement agreements.

FAQs

Can a generic use the same brimonidine and timolol concentrations in separate bottles?

Separate bottles may avoid the single-composition limitation in claim 1, but the manufacturer must assess the full patent family, product-specific use claims, induced-infringement risk, and FDA substitution requirements.

Does using brimonidine tartrate and timolol maleate automatically infringe US 8,354,409?

No. The salt forms correspond to dependent claims 4 and 6, but infringement still requires the other inherited limitations, including the 0.2%/0.5% concentrations, sterility, single composition, and topical ophthalmic suitability.

Can a generic avoid the patent by removing benzalkonium chloride?

Removing benzalkonium chloride may avoid claim 3. It does not avoid claim 1 if the product otherwise contains the claimed fixed combination in a sterile topical ophthalmic composition.

Is twice-daily dosing required for every infringement theory?

No. Twice-daily dosing is required by claim 11, but composition claim 1 does not require a dosing frequency. Claims 12 through 21 also depend on the method claim and introduce comparative clinical-outcome limitations.

Does FDA approval prove that a generic does not infringe the patent?

No. FDA approval and patent clearance are separate issues. An ANDA applicant must address listed patents through the applicable certification, and a Paragraph IV certification can lead to patent litigation before commercial launch.

References

United States Patent and Trademark Office. (2013). U.S. Patent No. 8,354,409, brimonidine and timolol pharmaceutical compositions and methods of use.
U.S. Food and Drug Administration. (n.d.). Combigan (brimonidine tartrate and timolol maleate) ophthalmic solution, prescribing information.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book, NDA 021398.
U.S. Food and Drug Administration. (n.d.). Orange Book: Questions and answers regarding patent and exclusivity information.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2003228480	⤷ Start Trial
Brazil	0302584	⤷ Start Trial
Canada	2440764	⤷ Start Trial
China	100558364	⤷ Start Trial
China	101664414	⤷ Start Trial
China	112219061	⤷ Start Trial
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Details for Patent: 8,354,409

Summary for Patent: 8,354,409