United States Patent 8,933,120: Bimatoprost 0.01% Ophthalmic Composition Patent Scope and Patent Landscape

United States Patent No. 8,933,120 protects ophthalmic compositions containing low-dose bimatoprost, principally 0.01% or 0.015% w/v, with approximately 0.02% w/v benzalkonium chloride. The broadest independent claim is a composition claim. The later claims add excipients, pH, glaucoma-treatment use, once-daily dosing, and comparative reductions in ocular hyperemia against a 0.03% bimatoprost/0.005% benzalkonium chloride formulation.

The patent is directed to the Lumigan 0.01% formulation concept associated with Allergan, now within AbbVie’s ophthalmology portfolio. Its commercial significance lies in the formulation and clinical-performance limitations, rather than in the bimatoprost molecule itself, which was covered by earlier patents and is now off-patent as an active ingredient.

What does United States Patent 8,933,120 protect?

The patent protects a bimatoprost ophthalmic composition with two central concentration requirements:

Element	Claim requirement
Bimatoprost	About 0.01%-0.015% w/v
Benzalkonium chloride	About 0.02% w/v
Dosage form	Ophthalmic composition
Core commercial concentration	0.01% w/v bimatoprost
Comparative reference formulation	0.03% w/v bimatoprost and 0.005% w/v benzalkonium chloride

Claim 1 is the principal composition claim. Because it uses “comprising,” the claim is open-ended. A competing product can contain additional ingredients and still fall within the claim if it contains the recited bimatoprost and benzalkonium chloride concentrations.

The claim does not require:

A particular brand name;
A particular bottle, dropper, or container;
A specific preservative system beyond the recited benzalkonium chloride;
A particular manufacturing process;
A particular indication, unless the claim is one of the later method or treatment claims;
A particular dosage volume;
A particular excipient package, unless a dependent claim is asserted.

How broad is claim 1 of US 8,933,120?

Claim 1 has potentially meaningful product-level breadth because it covers a composition based on concentration ranges rather than a closed formula.

Its essential limitations are:

The product must be ophthalmic.
It must contain bimatoprost.
Bimatoprost must be present at about 0.01%-0.015% w/v.
Benzalkonium chloride must be present at about 0.02% w/v.

The term “about” creates a claim-construction issue. It does not automatically cover every concentration near the stated value. Its scope depends on intrinsic evidence, prosecution history, specification examples, analytical tolerances, and the way a person skilled in ophthalmic formulation would understand the term.

A product labeled at 0.01% bimatoprost and 0.02% benzalkonium chloride is the clearest commercial embodiment. A product labeled at 0.015% bimatoprost also falls within the express range. A formulation labeled at 0.009% or 0.016% would require a separate analysis of the meaning of “about” and potential equivalents.

What do claims 2 through 12 add?

Claims 2 through 6 mainly confirm specific concentrations already identified in claim 1.

Claim	Added limitation	Practical effect
2	About 0.01% bimatoprost	Narrows claim 1 to approximate 0.01%
3	Exactly 0.01% bimatoprost	Exact concentration embodiment
4	About 0.015% bimatoprost	Approximate upper-end embodiment
5	Exactly 0.015% bimatoprost	Exact upper-end embodiment
6	0.02% benzalkonium chloride	Express preservative concentration
7	Dibasic sodium phosphate	Buffer-system limitation
8	Citric acid monohydrate	Excipient limitation
9	Sodium chloride	Tonicity-agent limitation
10	Hydrochloric acid and sodium hydroxide for pH adjustment	Manufacturing/formulation limitation
11	Water	Aqueous composition limitation
12	pH of about 7.3	Finished-product pH limitation

Claims 7 through 12 create narrower fallback positions. They may be useful in litigation if a defendant disputes infringement of claim 1 but markets a composition closely matching the disclosed commercial formulation.

Claims 2 through 6 have limited independent commercial value because a product meeting claim 1 will often meet one or more of them. Claims 7 through 12 are more useful for distinguishing a competing composition with the same active and preservative concentrations but a different buffer, tonicity agent, or pH.

What do claims 13 through 20 protect?

Claims 13 through 20 add clinical-performance limitations. The claimed 0.01% bimatoprost/0.02% benzalkonium chloride composition must:

Lower intraocular pressure;
Produce less hyperemia than the comparator composition;
Be compared with 0.03% bimatoprost/0.005% benzalkonium chloride;
In several claims, be administered once daily;
In claims 17 and 20, be effective for treating glaucoma.

The comparator is important. These claims are not directed only to a low-dose formulation. They require a relationship between the claimed product and the older 0.03% bimatoprost formulation.

Claims	Functional limitation
13	Lower intraocular pressure and less hyperemia than comparator
14	Once-daily use with equivalent pressure reduction
15	Administration at least once daily
16	Once-daily use with greater pressure reduction
17	Once-daily glaucoma treatment
18	Similar comparative limitation in a separate claim branch
19	Once-daily efficacy equivalent to comparator
20	Once-daily glaucoma treatment

The wording supplied for claims 17 and 20 refers to “composition method.” The issued patent should control for claim interpretation because transcription errors can affect whether a claim is characterized as a composition claim, method-of-treatment claim, or dependent claim.

What formulations are protected by US 8,933,120?

The strongest formulation match is an aqueous ophthalmic solution containing:

0.01% w/v bimatoprost;
0.02% w/v benzalkonium chloride;
Dibasic sodium phosphate;
Citric acid monohydrate;
Sodium chloride;
Water;
Hydrochloric acid and sodium hydroxide for pH adjustment;
A pH of approximately 7.3.

A formulation does not need to contain every listed excipient to infringe claim 1. Those components become mandatory only when a dependent claim is asserted.

This distinction matters in generic product analysis. A generic manufacturer can avoid claims 7 through 12 by changing the buffer, omitting sodium chloride, using a different pH-adjustment system, or selecting a different pH. Those changes do not avoid claim 1 if the product remains within the bimatoprost and benzalkonium chloride limitations.

Is US 8,933,120 a formulation patent or a method-of-use patent?

It is primarily a formulation patent, with additional treatment-use claims.

The patent’s main commercial barrier is claim 1, which can be asserted against a product based on its formulation. Claims 13 through 20 are narrower and depend on clinical or treatment-use facts. Method-of-treatment claims may be more difficult to enforce against a manufacturer because infringement can depend on the labeled indication, dosing instructions, promotional conduct, physician prescribing, and actual use.

A generic product with a label directing once-daily treatment of glaucoma may create a stronger risk under claims 13 through 20 than a product with a narrower or differently worded label. The composition claims remain the more direct product-facing risk.

What is the relationship to Lumigan 0.03% and Lumigan 0.01%?

The patent distinguishes the low-dose formulation from the earlier 0.03% product.

Product concept	Bimatoprost	Benzalkonium chloride	Patent relevance
Earlier Lumigan formulation	0.03%	0.005%	Comparator in claims 13-20
Low-dose formulation	0.01%	0.02%	Primary claimed commercial embodiment
Upper claimed concentration	0.015%	About 0.02%	Expressly covered by claims 1, 4 and 5

The patent strategy relies on a formulation tradeoff: lower bimatoprost exposure combined with a higher benzalkonium chloride concentration, supported by claims directed to reduced hyperemia and maintained or improved intraocular-pressure reduction.

The FDA-approved Lumigan 0.01% labeling identifies bimatoprost ophthalmic solution as a once-daily treatment for elevated intraocular pressure associated with open-angle glaucoma or ocular hypertension.[2] The product’s labeled dosage and indication align closely with the treatment limitations recited in the later claims.

When does US 8,933,120 lose exclusivity?

The patent’s enforceable term depends on its effective filing date, any continuation relationship, patent-term adjustment, terminal disclaimer, and any patent-term extension. The issue date alone does not establish the expiration date.

The patent was issued on January 13, 2015. Its effective expiration date must be determined from the USPTO patent record and applicable 35 U.S.C. §§ 154 and 156 calculations.[1,3] A commercial exclusivity analysis should separate:

Patent expiration;
FDA approval exclusivity;
Orange Book-listed patents;
Pediatric exclusivity;
Any litigation settlement date;
The date on which an ANDA applicant may obtain approval;
The date on which a generic may lawfully launch.

Bimatoprost is a small molecule, so biosimilar exclusivity is not relevant. Competitive entry would proceed through the ANDA pathway rather than the biosimilar pathway.

What is the Orange Book status of the patent?

The Orange Book is the controlling FDA source for patents listed against an approved drug product. A patent number’s existence does not, by itself, establish that the patent is currently listed against every bimatoprost product.

The relevant Orange Book review should identify:

The reference listed drug;
The specific strength and dosage form;
Whether US 8,933,120 is listed;
The patent-use code;
The patent expiration date recorded by FDA;
Any delisting, correction, or post-approval change.

The Orange Book distinguishes product, formulation, and method-of-use patents. A patent may be listed against one strength or approved product but not another. The FDA’s current electronic Orange Book should be used for the operative listing and expiration data.[4]

What Paragraph IV challenges and generic-entry risks exist?

An ANDA applicant seeking approval before expiration of a listed patent may submit a Paragraph IV certification alleging that the patent is invalid, unenforceable, or will not be infringed.[5]

For this patent, likely Paragraph IV theories would focus on:

Lack of written description for the claimed concentration range;
Enablement of the full “about 0.01%-0.015%” range;
Obviousness over the earlier 0.03% bimatoprost formulation;
Obviousness of the 0.02% benzalkonium chloride concentration;
Inherency or obviousness of the comparative hyperemia limitation;
Indefiniteness of “about”;
Failure to establish the claimed pressure-reduction or hyperemia result across the full scope;
Noninfringement based on concentration, excipient, pH, or labeling differences.

The strongest infringement case would involve a generic labeled or analytically tested at 0.01% bimatoprost and 0.02% benzalkonium chloride. A generic using 0.01% bimatoprost with a different preservative concentration may avoid claim 1 but could still require analysis under equivalents. A product using 0.015% bimatoprost remains within the express claimed range.

How strong is the patent estate?

US 8,933,120 appears commercially stronger as a formulation patent than as a standalone method-of-treatment patent.

Factor	Assessment
Product specificity	High
Dependence on exact concentration	High
Coverage of 0.01% product	Direct
Coverage of excipient changes	Limited under dependent claims; broad under claim 1
Clinical-performance limitations	Narrower and evidence-dependent
Small-molecule biosimilar risk	Not applicable
Generic design-around potential	Moderate
Need for analytical testing	High
Litigation leverage	Greatest against matching 0.01%/0.02% products

The patent does not block all bimatoprost ophthalmic products. It targets a defined concentration and preservative combination. A competitor can potentially design around it through a different bimatoprost strength, alternative preservative system, preservative-free packaging, or a different formulation architecture. Those alternatives may encounter separate patents, regulatory comparability issues, stability constraints, or clinical-development costs.

What manufacturing and IP barriers affect generic entry?

Manufacturing a noninfringing ophthalmic product requires more than changing a label concentration. The applicant must address:

Sterility assurance;
Preservative effectiveness;
Container-closure compatibility;
Bimatoprost stability;
pH and osmolality;
Drop-size consistency;
Extractables and leachables;
In-use stability;
Bioequivalence or other ANDA requirements;
Accurate labeling and patent certification.

A formulation change that avoids the 0.02% benzalkonium chloride limitation may create a separate regulatory burden. A preservative-free product may require multidose container technology or single-use packaging. A pH change may affect tolerability, stability, or ocular exposure.

Does the patent cover licensing deals or settlement agreements?

The claim set alone does not establish a license, authorized generic arrangement, covenant not to sue, or Paragraph IV settlement. Those issues require review of SEC filings, FDA litigation records, district court dockets, and any publicly disclosed agreement.

The commercially relevant parties are likely to include the reference-product sponsor, ANDA applicants, generic ophthalmic manufacturers, and authorized-generic or licensing partners. No licensing right is implied merely because a company markets a bimatoprost product.

Key Takeaways

US 8,933,120 primarily protects a bimatoprost ophthalmic formulation containing about 0.01%-0.015% w/v bimatoprost and about 0.02% w/v benzalkonium chloride.
The 0.01% bimatoprost/0.02% benzalkonium chloride formulation is the central commercial embodiment.
Claims 7 through 12 add excipients, pH, and formulation details that provide narrower fallback protection.
Claims 13 through 20 add comparative efficacy, reduced hyperemia, once-daily dosing, and glaucoma-treatment limitations.
The patent is relevant to ANDA products that match the low-dose bimatoprost and preservative concentrations.
Bimatoprost is a small molecule; biosimilar analysis does not apply.
Generic risk depends on the product’s tested composition, proposed labeling, Orange Book listing, patent term, and any Paragraph IV litigation or settlement.
The patent’s precise expiration date should be taken from the USPTO patent-term record and current FDA Orange Book entry, not inferred from the issue date.

FAQs

Does 0.01% bimatoprost alone infringe US 8,933,120?

Not necessarily. Claim 1 also requires about 0.02% w/v benzalkonium chloride. A product containing 0.01% bimatoprost with a different preservative concentration would require a separate infringement analysis.

Does a preservative-free bimatoprost product fall within the patent?

A preservative-free product would not literally satisfy the benzalkonium chloride limitation in claim 1. Claims 13 through 20 would also require analysis of the applicable composition and treatment limitations.

Can a generic avoid the patent by using 0.015% bimatoprost?

No. Claims 1, 4 and 5 expressly cover approximately or exactly 0.015% bimatoprost when the benzalkonium chloride limitation is also met.

Does changing the pH avoid the patent?

Changing the pH may avoid claim 12, but it does not necessarily avoid claim 1. Claim 1 does not recite a pH limitation.

Is the patent relevant to latanoprost, travoprost, or tafluprost products?

No, not directly. The independent claim requires bimatoprost. Other prostaglandin analog products would require separate patent and regulatory analyses.

References

United States Patent and Trademark Office. (2015). U.S. Patent No. 8,933,120, Bimatoprost ophthalmic composition.
U.S. Food and Drug Administration. (n.d.). Lumigan (bimatoprost ophthalmic solution) prescribing information.
35 U.S.C. §§ 154, 156 (2024).
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Electronic Orange Book.
21 C.F.R. § 314.101; 21 U.S.C. § 355(j).

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

Details for Patent: 8,933,120

Summary for Patent: 8,933,120