US Patent 8,299,118: Bimatoprost 0.01% Patent Scope, Validity, Litigation, and Generic Entry Risk

US Patent 8,299,118 covers once-daily treatment of glaucoma or ocular hypertension with a bimatoprost ophthalmic solution containing approximately 0.01% bimatoprost and 0.02% benzalkonium chloride, commonly associated with Lumigan 0.01%. The patent does not claim bimatoprost generally or the formulation as a composition. Its claims are method-of-treatment claims that depend on concentration, dosing frequency, comparative efficacy, reduced hyperemia, formulation pH, buffering components, and, in some claims, increased corneal permeability.

The patent was assigned to Allergan, Inc. and issued on October 30, 2012. Its ordinary 20-year term was projected to expire in 2027 based on the claimed priority date. Its practical exclusionary value was materially reduced by the Federal Circuit’s decision in Allergan, Inc. v. Sandoz Inc., which held the asserted claims obvious over the prior art.[1]

What does US Patent 8,299,118 protect?

The patent protects selected clinical uses of a low-concentration bimatoprost formulation rather than the active ingredient itself.

Claim group	Independent claim	Core limitation
Reduced hyperemia and IOP lowering	1	Once-daily administration of about 0.01% bimatoprost and about 0.02% BAK, with lower IOP and less hyperemia than 0.03% bimatoprost/0.005% BAK
Maintained IOP benefit	7	The lower-dose formulation lowers IOP without substantial reduction in benefit compared with the 0.03% formulation
Reduced bimatoprost exposure	15	Treatment uses less bimatoprost while remaining effective for glaucoma or ocular hypertension
Increased permeability	23	The higher BAK concentration increases bimatoprost permeability across corneal epithelial cell layers

The dependent claims add narrower limitations:

pH of approximately 7.3;
solution dosage form;
topical administration;
glaucoma or ocular hypertension treatment;
open-angle glaucoma;
buffering or stabilizing ingredients selected from dibasic sodium phosphate heptahydrate, citric acid monohydrate, and EDTA;
reduced hyperemia;
maintained therapeutic effectiveness.

The patent therefore has four central technical themes:

Lower bimatoprost concentration.
Higher benzalkonium chloride concentration.
Once-daily ocular administration.
Comparable intraocular-pressure reduction with less hyperemia.

How narrow are the claims of US 8,299,118?

The claims are narrow in formulation concentration but broad in their use of functional and comparative limitations.

A potential infringing product generally would need to satisfy the following elements:

Required element	Claim significance
Bimatoprost	The claims do not cover other prostaglandin analogues such as latanoprost, travoprost, or tafluprost
Approximately 0.01% w/v concentration	A materially different concentration may avoid literal infringement, subject to claim construction and equivalents
Approximately 0.02% w/v BAK	This is a central limitation distinguishing the claimed formulation from the earlier 0.03%/0.005% formulation
Once-daily dosing	Twice-daily or non-daily labeling may avoid literal infringement of the independent claims
Ocular administration	Systemic or non-ocular use is outside the claim scope
Glaucoma or ocular hypertension	Cosmetic or unrelated ophthalmic uses are outside the claimed indication
Comparative therapeutic or tolerability result	Several claims require proof of lower hyperemia, preserved IOP reduction, or increased permeability

The independent claims do not simply cover dispensing a bottle containing 0.01% bimatoprost and 0.02% BAK. They require a treatment method. This distinction matters in generic litigation because product composition alone may not establish infringement. The prescribing information, proposed labeling, clinical evidence, and induced-infringement theory become important.

Claims 1 and 7 are particularly dependent on comparative performance against the 0.03% bimatoprost/0.005% BAK formulation. Claims 15 and 23 are more functional. Claim 15 focuses on using less bimatoprost while preserving clinical utility. Claim 23 focuses on increased permeability across corneal epithelial cell layers.

What formulation is protected by US 8,299,118?

The principal formulation is the low-dose bimatoprost product historically marketed as Lumigan 0.01%.

Formulation characteristic	Claimed value
Bimatoprost	About 0.01% w/v
Benzalkonium chloride	About 0.02% w/v
Administration	Once daily
Route	Topical ocular administration
pH	About 7.3 in dependent claims
Dosage form	Solution in dependent claims
Treatment	Glaucoma or ocular hypertension
Comparator	0.03% bimatoprost with 0.005% BAK

The patent’s commercial theory was that increasing BAK could improve ocular penetration sufficiently to permit a reduction in bimatoprost concentration. The lower bimatoprost concentration was associated with less conjunctival hyperemia while retaining IOP-lowering activity.

The formulation claims are not composition claims in the conventional sense. A party cannot necessarily be blocked from making or selling every ophthalmic solution containing 0.01% bimatoprost and 0.02% BAK solely because of the patent. The risk is greatest where the product is labeled for once-daily glaucoma or ocular-hypertension treatment in a manner that practices the claimed clinical limitations.

When does US Patent 8,299,118 expire?

The patent issued October 30, 2012. Public patent records identify a 2007 priority date and a projected 2027 patent-term endpoint. The ordinary expiration date is generally reported as July 13, 2027, based on the earliest relevant priority date.[2]

Milestone	Date
Earliest reported priority date	July 13, 2007
Patent issued	October 30, 2012
Projected ordinary expiration	July 13, 2027
Patent type	Utility patent
Patent holder at issuance	Allergan, Inc.

The expiration date is less important than the validity ruling discussed below. A patent that remains listed through its nominal term can have limited practical enforcement value if the asserted claims have been held invalid.

What is the Orange Book status of US Patent 8,299,118?

US Patent 8,299,118 was associated with Allergan’s Lumigan 0.01% product and was listed in connection with the FDA-approved bimatoprost ophthalmic solution. The relevant reference product was Lumigan 0.01%, NDA 022369, approved by the FDA in 2010.[3]

The Orange Book listing created an ANDA certification issue for generic applicants. A generic applicant seeking approval before patent expiry could submit:

a Paragraph III certification, accepting delayed approval until patent expiration;
a Paragraph IV certification, asserting that the patent was invalid, unenforceable, or not infringed; or
a section viii statement, where the proposed labeling carved out the patented method.

The patent’s method-of-use character made labeling and indication strategy important. A generic applicant could attempt to avoid infringement by omitting the patented use from its proposed label, although the feasibility of a carve-out would depend on the FDA-approved indications and the scope of the listed patent.

What did Allergan v. Sandoz decide about the patent?

The Federal Circuit addressed the validity of US Patent 8,299,118 in Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293 (Fed. Cir. 2015).[1]

The appellate court held that the asserted claims were obvious. The court considered prior-art disclosures involving:

bimatoprost ophthalmic treatment;
reductions in active-drug concentration;
benzalkonium chloride as an ophthalmic preservative;
the known effect of BAK on corneal permeability;
the clinical objective of reducing hyperemia while maintaining IOP reduction.

The decision rejected the position that the claimed concentration combination produced a sufficiently unexpected result to overcome the obviousness case. The court treated the claimed formulation as an optimization of known variables rather than an invention requiring more than routine experimentation.

What was the legal effect?

The decision materially weakened the patent estate:

The asserted claims could not support an injunction against the prevailing generic challenger.
A Paragraph IV challenger obtained a strong invalidity position.
The nominal 2027 expiration date did not represent a reliable market-exclusivity date.
Related claim sets sharing the same concentration and comparative-performance theory faced similar obviousness exposure.
Future litigation would need to distinguish the prior art or rely on unasserted claims with materially different limitations.

The decision did not make every conceivable bimatoprost patent invalid. It addressed the asserted claims and the prior-art record before the court. A separate patent with different claims, a different formulation, or a different manufacturing process would require separate analysis.

Which companies challenged the bimatoprost 0.01% patent?

Sandoz was the principal named challenger in the Federal Circuit litigation concerning US Patent 8,299,118. The case arose from an ANDA challenge to Allergan’s Lumigan 0.01% product.[1]

The broader generic market included companies developing or marketing bimatoprost ophthalmic solutions. The relevant competitive distinction is between:

products matching the 0.01% bimatoprost/0.02% BAK formulation;
products using different preservative systems;
products using different bimatoprost concentrations;
preservative-free or reduced-preservative products; and
products relying on non-infringing labeling.

Because the patent was a method patent, ANDA strategy could focus on both patent invalidity and non-infringement. The Federal Circuit’s obviousness holding reduced the need for a generic entrant to rely exclusively on a labeling carve-out.

What Paragraph IV risks exist for generic bimatoprost?

A Paragraph IV challenge to US Patent 8,299,118 would have presented a substantial invalidity case based on obviousness. The principal arguments would be:

the prior art disclosed bimatoprost for glaucoma and ocular hypertension;
the prior art disclosed ophthalmic BAK-containing formulations;
BAK’s corneal-permeability effect was known;
reducing the active concentration was a predictable formulation adjustment;
the claimed combination did not produce an unexpected result sufficient to establish nonobviousness.

Allergan’s counterarguments centered on the claimed balance between efficacy and tolerability. The commercial product used a lower bimatoprost concentration but retained IOP reduction while reducing hyperemia. The Federal Circuit concluded that these results did not overcome the obviousness evidence.

A generic sponsor still would face product-specific infringement questions. A product with a different BAK concentration, different preservative, different dosing schedule, or different indication could avoid some claim elements. Conversely, a product matching the claimed formulation and label would face greater exposure even after the validity ruling if any claim remained legally enforceable in the relevant proceeding.

How strong is the patent estate for Lumigan 0.01%?

The patent estate was commercially meaningful before the Federal Circuit decision but is weak as an exclusionary barrier after the decision.

Factor	Assessment
Claim type	Method of treatment
Concentration specificity	High
Dependence on comparative results	High
Composition claim coverage	Limited or absent in the quoted claims
Prior-art exposure	Significant
Federal Circuit validity outcome	Asserted claims held obvious
Manufacturing barrier	Low based on the quoted claims
Generic substitution risk	High
Remaining value	Historical prosecution, litigation, licensing, and formulation know-how rather than strong exclusion

The patent does not create a durable manufacturing barrier. A generic manufacturer would not need to duplicate a proprietary synthesis route merely to produce the claimed ophthalmic solution. The active ingredient, excipient system, filling process, sterility controls, and container-closure system could be developed through conventional ophthalmic manufacturing pathways.

The strongest residual protection would have been regulatory and commercial rather than patent-based: FDA approval requirements, bioequivalence work, sterile manufacturing capability, physician adoption, and market access.

What licensing deals or settlement agreements affected the patent?

The cited appellate decision establishes the Sandoz litigation and its outcome. Publicly available records associated with the patent do not establish a broadly reported, industry-wide license that preserved exclusivity through the patent’s nominal 2027 expiry.

Generic patent settlements must be evaluated from the actual agreement, court docket, and FDA approval chronology. A settlement can include a license, an agreed launch date, supply terms, or restrictions unrelated to the patent’s ultimate validity. The Federal Circuit ruling prevents treating the patent’s nominal expiration date as proof of a continuing commercial blockade.

How does US Patent 8,299,118 compare with competing glaucoma patents?

US Patent 8,299,118 differs from many glaucoma patents because it focuses on a specific low-dose formulation and clinical outcome.

Patent strategy	Typical protection	Relative position
Active-ingredient patent	Bimatoprost molecule or chemical class	Broader but generally earlier-expiring
Composition patent	Concentration, preservative, pH, vehicle	Can block manufacture and sale directly
Method patent	Administration for glaucoma or ocular hypertension	More dependent on labeling and clinical use
Delivery-system patent	Sustained release, implant, insert, or device	Can create a stronger product barrier
Manufacturing patent	Synthesis, purification, sterilization, or filling	Can restrict supply chain methods
US 8,299,118	0.01% bimatoprost/0.02% BAK once-daily treatment	Narrow formulation-specific method coverage

The patent’s commercial thesis was stronger than its claim architecture. The product benefit was clinically relevant, but the legal claims tied that benefit to a combination of parameters that the Federal Circuit viewed as predictable.

What generic launch scenarios exist?

Three launch scenarios were relevant:

Launch after successful Paragraph IV litigation

A generic applicant could launch after prevailing on invalidity or non-infringement. The Sandoz decision provides the clearest precedent for this route.

Launch under a non-infringing label

A sponsor could seek approval with labeling that omits the patented method, if the FDA-approved labeling structure permits a meaningful carve-out. This approach would require careful assessment of induced infringement and the remaining indication language.

Launch after nominal patent expiry

A sponsor could rely on a Paragraph III certification and await the reported 2027 expiration date. This would be the lowest patent-litigation-risk path but would sacrifice earlier market entry.

The market impact of a generic launch would depend on substitution rules, payer formularies, ophthalmologist prescribing, product availability, and whether the generic matches Lumigan 0.01% in preservative system and dosing instructions.

What revenue exposure was associated with the patent?

US Patent 8,299,118 protected a key commercial reformulation of bimatoprost. Lumigan 0.01% was approved as an FDA reference product and competed in the prostaglandin-analogue glaucoma market against latanoprost, travoprost, and other IOP-lowering therapies.[3]

The patent’s revenue exposure was concentrated in:

the branded Lumigan 0.01% product;
price premium over generic bimatoprost;
reduced hyperemia positioning;
once-daily adherence;
ophthalmology formulary placement; and
switching from the older 0.03% formulation.

The precise revenue attributable to the patent cannot be equated with total Lumigan sales. The product’s market position also depended on brand, regulatory approval, clinical familiarity, manufacturing quality, and commercial contracting. Once the asserted claims were held obvious, generic-entry risk increased substantially and the patent could no longer be treated as a reliable long-term revenue shield.

Key Takeaways

US Patent 8,299,118 covers methods using approximately 0.01% bimatoprost and 0.02% BAK once daily.
The quoted claims require treatment of glaucoma or ocular hypertension and, in several claims, comparative efficacy, reduced hyperemia, or increased permeability.
The patent is primarily a method-of-treatment patent, not a broad composition or manufacturing patent.
The ordinary reported expiration date is July 13, 2027.
Lumigan 0.01%, NDA 022369, is the principal reference product associated with the patent.
The Federal Circuit held the asserted claims obvious in Allergan v. Sandoz.
The ruling substantially reduced the patent’s ability to delay generic bimatoprost entry.
Generic risk is highest for products matching the 0.01% bimatoprost/0.02% BAK formulation and once-daily glaucoma labeling.
Alternative preservative systems, concentrations, dosing instructions, and carved-out labels may reduce literal infringement exposure.
The patent does not create a significant manufacturing barrier based on the quoted claims.

Frequently Asked Questions

Is US Patent 8,299,118 a composition patent?

No. The quoted claims are methods of treating glaucoma or ocular hypertension. They do not independently claim every ophthalmic composition containing 0.01% bimatoprost and 0.02% BAK.

Does the patent cover Lumigan 0.03%?

No. The 0.03% bimatoprost and 0.005% BAK formulation is used as the comparator in the claims. The claimed treatment uses approximately 0.01% bimatoprost and 0.02% BAK.

Does a bimatoprost generic automatically infringe the patent?

No. Infringement depends on the product’s formulation, proposed labeling, dosing instructions, indication, and the scope and enforceability of the asserted claims.

Why is benzalkonium chloride important in the patent?

The claims rely on the higher BAK concentration as part of the theory that increased corneal permeability permits effective treatment with less bimatoprost and less hyperemia.

Can the patent support an injunction until 2027?

The nominal expiration date does not establish that result. The Federal Circuit’s obviousness ruling substantially limits the patent’s enforceability against the challenged generic product.

References

Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293 (Fed. Cir. 2015).
United States Patent No. 8,299,118, “Methods of treating glaucoma using bimatoprost ophthalmic solution,” issued October 30, 2012.
U.S. Food and Drug Administration. (2010). Lumigan (bimatoprost ophthalmic solution) 0.01% prescribing information and NDA 022369 materials. FDA.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	055050	⤷ Start Trial
Austria	E431152	⤷ Start Trial
Australia	2006227757	⤷ Start Trial
Brazil	PI0607447	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,299,118

Summary for Patent: 8,299,118