Details for Patent: 8,450,311

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Which drugs does patent 8,450,311 protect, and when does it expire?

Patent 8,450,311 protects MOXEZA and is included in one NDA.

This patent has twenty-three patent family members in fifteen countries.

Summary for Patent: 8,450,311

Title:	Pharmaceutical compositions containing a fluoroquinolone antibiotic drug
Abstract:	Pharmaceutical compositions containing a fluoroquinolone antibiotic drug are disclosed. The compositions exhibit improved homogeneity, improved bioavailability, lower turbidity or a combination thereof. The composition can be use as otic or nasal compositions, but are particularly useful as ophthalmic compositions.
Inventor(s):	Inmaculada Campins, Nuria Jiménez, Roman Vidal, Nuria Carreras, Carmen Martinez, Francisco Javier Galán
Assignee:	Harrow Inc
Application Number:	US12/474,307
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,450,311
Patent Claim Types: see list of patent claims	Composition; Formulation;

US Patent 8,450,311: Moxifloxacin Ophthalmic Composition Claims, Expiration, and Patent Landscape

US Patent No. 8,450,311 protects a narrow moxifloxacin ophthalmic formulation distinguished by four linked characteristics: moxifloxacin concentration, sodium chloride-to-drug ratio, xanthan-gum viscosity control, and low turbidity. The patent is directed to a Moxeza-type formulation rather than to moxifloxacin generally. Its strongest coverage is concentrated in compositions containing approximately 0.5% moxifloxacin, 0.55% to 0.70% sodium chloride, 0.60% to less than 0.75% xanthan gum, borate, a polyol such as sorbitol, a polyether alcohol surfactant such as tyloxapol, and a pH near neutrality.

The patent does not broadly block all moxifloxacin ophthalmic products. A competing product that omits xanthan gum, uses a different viscosity system, falls outside the specified concentration or ratio ranges, or fails the turbidity limitation may avoid literal infringement, subject to equivalents and claim construction.

What does US Patent 8,450,311 cover?

US 8,450,311 covers aqueous ophthalmic moxifloxacin compositions packaged for dropwise administration. The patent claims a formulation platform with controlled physical properties rather than the moxifloxacin molecule itself.

Patent identification

Item	Data
Patent	US 8,450,311 B2
Patent title	Ophthalmic compositions containing moxifloxacin
Publication	US 2012/0114702 A1
Issue date	May 28, 2013
Applicant or assignee	Alcon Research, Ltd.
Active ingredient	Moxifloxacin
Dosage form	Aqueous ophthalmic solution
Commercial product associated with formulation	Moxeza, moxifloxacin hydrochloride ophthalmic solution 0.5%
Primary commercial field	Bacterial conjunctivitis
Core formulation variables	Moxifloxacin, sodium chloride, xanthan gum, borate, polyol, surfactant, pH control, water, low turbidity

The claims use several transitional phrases with different legal effects. Claims 1 and 8 state that the pharmaceutical vehicle “consists essentially of” specified components. That language generally permits additional ingredients if they do not materially affect the basic and novel characteristics of the claimed formulation. The basic characteristics appear to include uniform drug distribution, acceptable viscosity, ophthalmic usability, and low turbidity.

Claim 16 uses “including” for the vehicle, which is generally more open-ended than “consisting essentially of.” It nevertheless requires every expressly recited component and imposes a narrower moxifloxacin and xanthan-gum concentration window.

How do the independent claims differ?

Claims 1, 8, and 16 are the principal infringement anchors. They overlap but are not identical.

Claim	Moxifloxacin	Sodium chloride-to-moxifloxacin ratio	Xanthan gum	Turbidity	Other limitations
1	At least 0.4% and less than 1.0% w/v	More than 1.0 and less than 1.7	At least 0.3% and less than 1.2% w/v; at least 90% of viscosity agent	Less than 13 NTU	Polyether alcohol surfactant, borate, polyol, pH agent, water
8	At least 0.4% and less than 1.0% w/v	1.1 to 1.4	At least 0.3% and less than 1.2% w/v; at least 90% of viscosity agent	Less than 10 NTU	Drop container; broader surfactant language
16	At least 0.4% and less than 0.7% w/v	1.1 to 1.4	At least 0.6% and less than 0.75% w/v; at least 90% of viscosity agent	Less than 13 NTU	Polyether alcohol surfactant, borate, polyol, pH agent, water

Claim 8 is the most structurally constrained independent claim because it requires a drop-dispensing container and turbidity below 10 NTU. Claim 16 is narrower in concentration but potentially broader in its vehicle transition because it uses “including.”

At a 0.5% moxifloxacin concentration, the sodium chloride limitations translate as follows:

Claim requirement	Approximate sodium chloride concentration
Ratio of 1.0 to 1.7	0.50% to 0.85% w/v
Ratio of 1.1 to 1.4	0.55% to 0.70% w/v

The ratio is calculated against the moxifloxacin concentration, not necessarily against moxifloxacin hydrochloride as supplied. Product testing must therefore define whether the relevant comparison is based on active moxifloxacin or the salt form described in the product documentation.

What formulations are protected by the dependent claims?

The dependent claims add commercial and analytical details that narrow the practical scope.

Surfactant limitations

Claims 1 and 16 require a polyether alcohol surfactant. Claims 11 and 15 repeat that limitation for claim 8 and claim 1, respectively. Claims 12, 13, 14, and 15 narrow the surfactant to an alkyl aryl polyether alcohol.

Tyloxapol is the commercially relevant example. The Moxeza label identifies tyloxapol among the inactive ingredients, together with boric acid, sodium chloride, sorbitol, xanthan gum, sodium hydroxide, and purified water (FDA, 2010).

A formulation using polysorbate, poloxamer, polyethylene glycol, or another surfactant would require a separate analysis. It would not automatically satisfy the polyether alcohol or alkyl aryl polyether alcohol limitations.

Polyol limitation

Claim 4 specifies sorbitol. Sorbitol is important because it contributes to tonicity and is present in the commercial Moxeza formulation. A different polyol may satisfy the broader claim if it performs the required compositional role, but it may not satisfy claim 4.

Xanthan-gum limitations

Claim 1 requires xanthan gum to constitute at least 90% by weight of the viscosity-enhancing agent. Claim 5 narrows the vehicle so that the viscosity-enhancing agent consists of xanthan gum.

Claims 10 and 13 impose the same all-xanthan-gum concept under claim 8. Claim 16 narrows the xanthan-gum concentration to at least 0.6% and less than 0.75% w/v.

These limitations create a meaningful design-around opportunity. A formulation using carbomer, hydroxypropyl methylcellulose, hydroxyethyl cellulose, carboxymethylcellulose, or a mixed polysaccharide system may fall outside claims requiring xanthan gum to comprise at least 90% of the viscosity agent.

pH and turbidity limitations

Claims 7, 9, 14, and 17 specify a pH of 6.8 to 7.4. Claims 7 and 17 also require turbidity below 10 NTU.

The turbidity limitation is a substantive claim element. A product with the correct ingredients but turbidity of 10 NTU or more may avoid claims requiring less than 10 NTU. Claim 1 and claim 16 allow turbidity below 13 NTU, while claim 8 and several dependent claims require below 10 NTU.

A freedom-to-operate analysis should use the patent’s test method, instrument configuration, sample preparation, and measurement conditions. NTU results can vary with dilution, equilibration time, container, temperature, and instrument calibration.

When does US 8,450,311 lose exclusivity?

The patent’s ordinary statutory term runs approximately 20 years from the earliest effective nonprovisional filing date. Public patent records associate the application with a 2009 priority date and a 2010 US nonprovisional filing period. On that basis, the expected expiration is approximately 2029 to 2030, subject to the patent’s official term calculation, patent-term adjustment, and any terminal disclaimer.

Milestone	Date
Earliest cited priority period	November 2009
US application period	November 2010
Publication	May 10, 2012
Issue	May 28, 2013
Expected statutory expiry	Approximately November 2029 to November 2030

The patent does not receive a separate period of regulatory patent-term extension merely because it covers an ophthalmic drug formulation unless the statutory requirements for patent-term extension are met. Any extension must be confirmed through the USPTO and FDA records.

What is the Orange Book status of the patent?

The formulation is associated with Moxeza, NDA 022223, approved by FDA in 2010. Moxeza contains moxifloxacin hydrochloride ophthalmic solution 0.5% and uses the ingredient profile reflected in the patent, including xanthan gum, sorbitol, tyloxapol, sodium chloride, boric acid, sodium hydroxide, and purified water (FDA, 2010).

The Orange Book analysis must distinguish between:

1. patents listed for Moxeza;
2. patents listed for Vigamox;
3. patents covering moxifloxacin as a chemical entity;
4. patents covering ophthalmic formulations; and
5. patents covering approved methods of use.

US 8,450,311 is a formulation patent, not a compound patent. Its relevance to an abbreviated new drug application depends on whether the ANDA product is intended to reference the Moxeza formulation and whether the listed patent is still reported for the relevant NDA.

An ANDA applicant that seeks approval before the listed patent’s expiration could file a Paragraph IV certification. The patent holder could then bring an infringement action within 45 days, potentially triggering a 30-month stay under the Hatch-Waxman framework (21 U.S.C. § 355(j)(5)(B)(iii)).

Which companies are challenging the patent?

No specific Paragraph IV challenger, district-court case, or settlement agreement is identified in the patent text or the FDA product label cited here. Generic moxifloxacin ophthalmic products have historically focused on the active ingredient and the widely used 0.5% ophthalmic dosage form, but a generic product need not practice every Moxeza-specific formulation limitation.

A Paragraph IV case would turn on the actual ANDA formulation, not merely on the use of moxifloxacin. The most material questions would be whether the product contains:

• xanthan gum at the claimed concentration;
• a viscosity agent that is at least 90% xanthan gum;
• sodium chloride within the claimed ratio;
• a qualifying polyether alcohol surfactant;
• borate and a polyol;
• turbidity below the applicable threshold; and
• pH within the dependent-claim range.

How strong is the patent estate for Moxeza?

The estate is technically narrow but commercially relevant. Its strength comes from the combination of quantitative limitations rather than from any single ingredient.

Strengths

• The claims identify a specific commercial formulation architecture.
• The low-turbidity limitation can distinguish otherwise similar products.
• Claims 1, 8, and 16 provide overlapping concentration ranges.
• Dependent claims capture sorbitol, alkyl aryl polyether alcohols, all-xanthan-gum systems, drop containers, and near-neutral pH.
• The claims can reach formulation changes that retain the same inactive-ingredient platform.

Weaknesses

• Moxifloxacin at approximately 0.5% is conventional in ophthalmic products.
• Sodium chloride, borate, sorbitol, surfactants, xanthan gum, and pH adjustment are individually familiar excipients.
• The claims depend heavily on measured properties and exact concentration ranges.
• A competitor may design around the patent by changing the viscosity agent, surfactant, sodium chloride ratio, turbidity, or moxifloxacin concentration.
• “Consisting essentially of” language creates potential disputes over whether an added excipient materially changes the claimed formulation.

The main validity risks would likely involve obviousness, written description, enablement, indefiniteness of functional or measurement limitations, and anticipation by earlier ophthalmic formulations. The combination of ranges and turbidity performance may support patentability, but those same limitations create proof burdens in litigation.

How does Moxeza compare with Vigamox?

Attribute	Moxeza	Vigamox
Active ingredient	Moxifloxacin hydrochloride	Moxifloxacin hydrochloride
Strength	0.5%	0.5%
Dosage form	Ophthalmic solution	Ophthalmic solution
Xanthan gum	Present in labeled formulation	Not the defining formulation platform
Sorbitol	Present	Not the principal distinguishing excipient
Tyloxapol or related surfactant	Present	Different formulation profile
Relevance of US 8,450,311	High	Lower unless the product practices the claimed excipient combination
Approved use	Bacterial conjunctivitis	Bacterial conjunctivitis

US 8,450,311 is more relevant to Moxeza than to standard Vigamox. A generic referencing Vigamox may avoid the patent if its formulation does not contain the claimed xanthan-gum and surfactant system. A generic referencing Moxeza faces greater exposure if its composition reproduces the claimed ratios and turbidity characteristics.

What generic launch risks exist?

The principal launch scenarios are:

Scenario	Patent risk
Generic uses no xanthan gum	Lower literal-infringement risk
Generic uses xanthan gum below 0.3%	Avoids claim 1 and claim 8 concentration limitation
Generic uses xanthan gum at 0.6% to below 0.75%	Higher risk under claim 16
Generic uses non-polyether surfactant	Potentially avoids claims requiring polyether alcohol
Generic uses sodium chloride ratio below 1.1 or above 1.4	Avoids the narrower ratio claims
Generic has turbidity at or above 10 NTU	May avoid claims 8, 7, 9, 14, and 17, but not necessarily claims 1 or 16
Generic changes pH outside 6.8 to 7.4	May avoid pH-dependent claims
Generic launches after patent expiration	No ordinary infringement risk from the expired patent

The commercial risk is highest for an ANDA that intentionally matches Moxeza’s inactive-ingredient system to obtain pharmaceutical equivalence or a similar product profile. A formulation that references the same active ingredient and strength but uses a different vehicle may have materially lower exposure.

What manufacturing and geographic barriers remain?

US 8,450,311 is a US patent. It does not by itself create equivalent rights in Europe, Canada, Japan, China, or other jurisdictions. Foreign protection depends on national members of the patent family, prosecution outcomes, maintenance, and local expiry dates.

The manufacturing barrier is moderate. The formulation uses commercially available excipients, and the claimed composition does not require a proprietary synthesis route for moxifloxacin. The more difficult development work concerns:

• achieving uniform moxifloxacin distribution;
• controlling xanthan-gum hydration and viscosity;
• maintaining low turbidity;
• controlling pH and tonicity;
• obtaining reproducible drop delivery; and
• demonstrating stability in the selected container.

The patent therefore creates a formulation and regulatory-development barrier more than a raw-material or manufacturing monopoly.

Key Takeaways

• US 8,450,311 is a formulation patent focused on Moxeza-type moxifloxacin ophthalmic solutions.
• The central combination is 0.4% to less than 1.0% moxifloxacin, controlled sodium chloride ratio, xanthan gum, borate, polyol, surfactant, near-neutral pH, and low turbidity.
• Claim 16 is narrower in moxifloxacin and xanthan-gum concentration but may be broader in its vehicle language.
• Moxeza is the product most closely aligned with the patent; Vigamox is less directly exposed.
• The expected patent expiry is approximately 2029 to 2030, depending on the official patent-term calculation.
• A generic can reduce risk by changing the viscosity system, surfactant, sodium chloride ratio, turbidity, pH, or xanthan-gum concentration.
• Paragraph IV exposure depends on the actual ANDA formulation and the patent’s contemporaneous Orange Book listing.
• No specific Paragraph IV litigation or settlement is identified in the cited materials.

FAQs

Does US 8,450,311 cover all 0.5% moxifloxacin eye drops?

No. It covers only products meeting the specified formulation limitations, including xanthan gum, sodium chloride ratio, qualifying surfactant, borate, polyol, and turbidity requirements.

Is Moxeza the product most directly covered by this patent?

Yes. Moxeza’s labeled inactive ingredients and 0.5% moxifloxacin strength closely correspond to the claimed formulation.

Can a generic use xanthan gum and still avoid the patent?

Potentially. Avoidance may be possible if xanthan gum is outside the claimed concentration range, is less than 90% of the viscosity agent, or is used with other formulation changes that avoid the remaining limitations.

Does the patent cover moxifloxacin synthesis or manufacturing?

No. The claims are directed to aqueous ophthalmic compositions and dispensing containers, not to chemical manufacture of moxifloxacin.

Does a Paragraph IV filing automatically invalidate US 8,450,311?

No. A Paragraph IV certification is a regulatory patent challenge. Invalidation requires a judicial determination or another legally effective disposition.

References

1. Alcon Research, Ltd. (2013). Ophthalmic compositions containing moxifloxacin, U.S. Patent No. 8,450,311 B2. United States Patent and Trademark Office.

2. Food and Drug Administration. (2010). Moxeza (moxifloxacin hydrochloride ophthalmic solution) prescribing information. U.S. Department of Health and Human Services.

3. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. U.S. Department of Health and Human Services.

4. United States Code. (2024). 21 U.S.C. § 355(j), abbreviated new drug applications and patent certifications.

Drugs Protected by US Patent 8,450,311

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	MOXEZA	moxifloxacin hydrochloride	SOLUTION/DROPS;OPHTHALMIC	022428-001	Nov 19, 2010		DISCN	Yes	No	8,450,311		Y

International Family Members for US Patent 8,450,311

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	072071
Australia	2009257778
Brazil	PI0914971
Canada	2726616
Chile	2009001379
China	102056590