US Patent 8,629,111: Scope, Claim Strength, and US Landscape for Cyclosporin A Topical Ophthalmic Emulsion

United States Patent 8,629,111 claims a specific topical ophthalmic emulsion composition for treating human dry eye/keratoconjunctivitis sicca, with strict formulation limits (notably 0.05% cyclosporin A, 1.25% castor oil, 1.0% polysorbate 80, 0.05% acrylate/C10-30 alkyl acrylate cross-polymer) and controlled ocular systemic exposure (blood cyclosporin A “substantially no detectable concentration”). The claims also set pH (7.2 to 7.6) and require “cytosporin A is the only peptide present” within the emulsion.

The claim set as provided is a classic composition-of-matter with tight numerical ranges plus functional limitations (low systemic exposure; therapeutic effectiveness). This creates enforceability against close copycats that retain the same formulation core and marketing-approved use, while also narrowing scope such that products deviating in excipient selection, polymer identity, concentration, buffer chemistry, or pH may fall outside.

What exactly is being claimed (composition and structural limits)?

Core independent claim theme

The claims are directed to:

Dosage form: “topical ophthalmic emulsion”
Active: cyclosporin A at about 0.05% by weight
Essential excipients (in the independent claim formats):
- polysorbate 80 (about 1.0% by weight)
- acrylate/C10-30 alkyl acrylate cross-polymer (about 0.05% by weight)
- castor oil (about 1.25% by weight)
- water
Systemic exposure limit: upon administration, blood has substantially no detectable cyclosporin A
Peptide purity limit: cyclosporin A is the only peptide present
Optional but commonly specified:
- tonicity/demulcent component (glycerine in dependent claims) at about 2.2% by weight
- buffer (sodium hydroxide in dependent claims)
- pH 7.2 to 7.6 in dependent claims
Therapeutic indication language:
- dry eye
- keratoconjunctivitis sicca
- increasing tear production

Numerical fingerprint of the claimed emulsion

The numerical recipe repeated across claim families is unusually specific:

Component	Claimed level (by weight)	Appears in claims
Cyclosporin A	~0.05%	1, 13, 18
Castor oil	~1.25%	1, 13, 18
Polysorbate 80	~1.0%	1, 13, 18
Acrylate/C10-30 alkyl acrylate cross-polymer	~0.05%	1, 13, 18
Glycerine (tonicity/demulcent)	~2.2%	6, 9, 13, 15, 18
Buffer	(sodium hydroxide when specified)	5, 10, 14, 18
pH	~7.2 to ~7.6	12, 13, 19
Systemic exposure	“substantially no detectable” blood cyclosporin A	11, 16

This is not a broad “cyclosporin A emulsion for dry eye.” It is a formulation with constrained identity and amounts.

How strong are the claims structurally (composition vs. evidence-driven limitations)?

Composition limits are the strongest anchors

The tight recitations of excipient identity and weight percentages are the primary scope-defining elements. Courts generally treat these as concrete structural boundaries: if a competitor’s product uses different surfactant, different polymer class, materially different polymer content, or different oil phase component, non-infringement becomes easier to show.

Functional/systemic limitations can cut both ways

Two claim concepts also matter for infringement and validity posture:

“Only peptide present”
- This is a content purity limitation. If a formulation contains additional peptide(s) or peptide-like contaminants that qualify as peptides, the product could fall outside.
- It can also become an evidentiary flashpoint: assay methodology, peptide definition, and “present” threshold.
“Substantially no detectable concentration” of cyclosporin A in blood
- This is a pharmacokinetic limitation tied to clinical administration.
- It can narrow the practical scope but may require bridging evidence: detection method, sampling schedule, assay LLOQ, and the specific patient population and dosing regimen used.

Therapeutic effectiveness language

Claims that recite “therapeutically effective in treating dry eye / keratoconjunctivitis sicca” and “increasing tear production” add use-effect constraints. These can still be asserted if the formulation inherently meets the therapeutic profile, but the practical enforceability often depends on what the evidentiary record supports (clinical data, method of use, labeling alignment, etc.).

What is the scope of independent claim coverage based on your provided claim text?

Claim 1: composition + purity + systemic exposure

Claim 1 requires all of the following:

Cyclosporin A ~0.05%
Polysorbate 80
Acrylate/C10-30 alkyl acrylate cross-polymer
Water
Castor oil ~1.25%
cytosporin A is the only peptide present
substantially no detectable blood cyclosporin A (via dependent claim 11, but it is explicitly included there; claim 1 itself lists the peptide purity without the systemic limit unless you read only the 1 text provided)
Dependent claims attach glycerine/buffer/pH constraints.

So Claim 1’s immediate scope is primarily: the emulsion composition with a specific peptide composition.

Claims 13 and 18: tighter versions with explicit tonicity/demulcent and buffer/pH

Claim 13 locks in tonicity/demulcent at ~2.2% and includes buffer plus pH 7.2-7.6.
Claim 18 locks in:
- glycerine at ~2.2%
- sodium hydroxide buffer
- pH constraint is via dependent claim 19
- and still requires the only peptide limitation.

These claims are the most “product-like” and therefore typically the hardest for a close copycat to design around if they are marketing a directly comparable emulsion.

How do the dependent claims expand or narrow infringement risk?

Buffer and pH dependent branches

Buffer is sodium hydroxide in claims 5, 10, 14, 18.
pH range 7.2 to 7.6 appears in claims 12, 13, 19.

Infringement impact:
If a competitor uses a different buffer system (for example, phosphate or borate) or targets a pH outside 7.2 to 7.6, it may avoid these dependent claim elements, but could still potentially infringe an independent claim if the independent claim does not require those limitations. Your provided text indicates pH is explicitly tied in dependent claims and in claims 13/18. Claim 1 as provided does not include pH.

Tonicity/demulcent as glycerine

Glycerine as a tonicity/demulcent is limited in claims 3, 6, 15.

Infringement impact:
A product using sorbitol, mannitol, or other demulcents at similar levels may escape those dependents but still be within independents if the independent claim allows “tonicity agent or demulcent component” more generally.

Systemic exposure branch

“substantially no detectable concentration” of cyclosporin A in blood appears in claims 11, 16.

Infringement impact:
A formulation could still be composition-identical but differ in bioavailability profile due to changes in particle size, surfactant system, dosing, or ocular residence time. That gives potential defense leverage, but enforcement depends on what assay/detection threshold qualifies as “substantially no detectable.”

Indication/use branches

Dry eye, keratoconjunctivitis sicca, and tear production increase appear in claims 17, 20-22, 21, 23-27.

Infringement impact:
If a competitor’s product has the same formulation but is labeled for a different ocular use, the enforceability depends on claim language structure (product-by-process vs. method-of-treatment style vs. formulation “effective for” indication). Your provided claims read as composition claims with therapeutic effectiveness, which can still be asserted against products marketed for the covered conditions.

What is the likely patent landscape shape around this composition? (US strategic view)

Landscape mechanics for this type of claim

In US practice, the enforcement and freedom-to-operate for a topical cyclosporin emulsion typically clusters around:

Other cyclosporin A ocular formulations
- Different solvents/oils
- Different surfactants
- Different polymeric mucoadhesive or thickening agents
- Different viscosity/pH/buffer systems
Other topical cyclosporin dosage forms
- Solutions rather than emulsions
- Suspensions or gels
- Ocular implants
Bioavailability and systemic exposure related limitations
- Claims that aim to show minimal systemic absorption can create additional patent layers around dosing and formulation design.

Practical competitive design-around levers created by these claims

Because the claim text is so specific, competitors usually target differences in one or more “must-match” elements:

Replace castor oil with another oil phase component
Replace polysorbate 80 with another surfactant (e.g., polysorbate 20 or poloxamers)
Replace acrylate/C10-30 alkyl acrylate cross-polymer with another cross-linked polymer or a different thickener class
Change glycerine to a different tonicity/demulcent
Use a different buffer (non-sodium hydroxide) or shift pH outside 7.2 to 7.6
Add or include peptide-containing excipients or impurities (rare as a design-around, but the “only peptide present” clause creates a theoretical constraint)
Reformulate to show detectable cyclosporin A in blood at measurable levels under claim-tested conditions (high bar, but it is a litigation-facing lever)

Scope map: which competitor modifications are likely inside vs. outside?

Change to competitor product vs. claimed composition	Likely effect on independent scope (based on your claim set)
Same composition but pH slightly outside 7.2-7.6	May avoid dependent claim coverage tied to pH; could still remain within independent claims if pH is not required there
Different buffer than sodium hydroxide	May avoid dependents; independent coverage depends on whether buffer identity is required in independents (your claim 1 does not explicitly require sodium hydroxide)
Replace glycerine with another tonicity/demulcent	May avoid glycerine-specific dependents; independent claim allowance depends on whether the independent requires a specific tonicity/demulcent
Replace polysorbate 80	High risk of non-infringement because polysorbate 80 is explicitly required in claim 1/13/18
Replace castor oil	High risk of non-infringement because castor oil is explicitly required in claim 1/13/18
Replace cross-polymer with a different polymer	High risk of non-infringement because acrylate/C10-30 alkyl acrylate cross-polymer is explicitly required in claim 1/13/18
Keep composition but alter to yield detectable blood cyclosporin	Could attempt to avoid dependents with “substantially no detectable” limitations; may not help against dependents that do not require blood data, depending on claim structure in asserted claims

Where the claim set is most vulnerable (for challenge or design-around)?

Key vulnerabilities created by the provided claim wording

Dependence on “about” ranges: the phrase “about” can still capture close variants, but it increases the importance of prosecution history and measurement doctrine (not provided here).
“Only peptide present” clause: introduces analytic and definitional disputes (what is “a peptide,” detection limits, manufacturing impurities).
“Substantially no detectable” in blood: depends on assay sensitivity and study design. This can be a litigation-heavy limitation.

Key strengths created by the same wording

The numeric formulation fingerprint (0.05% cyclosporin A; 1.25% castor oil; 1.0% polysorbate 80; 0.05% cross-polymer) narrows the scope to a more specific product family.
The presence of muco-structure and emulsifier choices limits “generic” reformulation strategies.

Key Takeaways

US 8,629,111 claims a specific topical ophthalmic cyclosporin A emulsion with a tight formulation recipe: 0.05% cyclosporin A, 1.25% castor oil, 1.0% polysorbate 80, and 0.05% acrylate/C10-30 alkyl acrylate cross-polymer, plus optional glycerine ~2.2% and sodium hydroxide buffer, with pH 7.2 to 7.6 in key dependent formats.
The claim set includes two notable limiting features: “cyclosporin A is the only peptide present” and minimal systemic exposure defined as “substantially no detectable” cyclosporin A in blood.
Scope is narrower than a generic “cyclosporin emulsion for dry eye” and is most exposed to design-arounds that change one of the explicitly required excipients (oil phase, surfactant, or polymer thickener) or alter buffer/pH and systemic exposure profile.
For competitive FTO and infringement evaluation, the priority is to compare the competitor’s product composition against the numeric fingerprint and then assess whether any asserted claim version includes the pH, glycerine, sodium hydroxide, and blood-detection limitations.

FAQs

1) Does the patent cover any cyclosporin A emulsion for dry eye?

No. Coverage is anchored to the specific emulsion composition and, in the claim text provided, to cyclosporin A being the only peptide present, plus additional dependent limitations on buffer, glycerine, pH, and systemic exposure.

2) Which ingredients are most critical to infringement risk?

The highest-risk elements are the explicitly required excipients and levels: castor oil (~1.25%), polysorbate 80 (~1.0%), and acrylate/C10-30 alkyl acrylate cross-polymer (~0.05%), along with cyclosporin A (~0.05%).

3) Can a competitor avoid the pH-limited dependent claims by changing pH?

Yes, changing pH away from 7.2 to 7.6 targets the dependent claims that expressly require that range. Whether that avoids the independent claims depends on whether the asserted claim includes the pH limitation.

4) How does “substantially no detectable” cyclosporin in blood affect enforcement?

It creates a dependence on clinical/pharmacokinetic testing thresholds. The competitor may argue that under its dosing and assay conditions, blood levels are detectable, but the applicability depends on which specific claim version is asserted.

5) What is the most meaningful design-around lever besides excipient swaps?

Changing buffer chemistry and pH and showing a different systemic exposure profile are meaningful because key dependents tie to sodium hydroxide and pH 7.2 to 7.6, and to minimal systemic detection.

References

[1] U.S. Patent No. 8,629,111 (provided claim text as supplied by user).

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World Intellectual Property Organization (WIPO)	2005032577	⤷ Start Trial
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Details for Patent: 8,629,111

Summary for Patent: 8,629,111