US Patent 12,201,615: Claim Scope, Exclusivity, Orange Book Position and Generic Entry Risk

US Patent 12,201,615 covers a narrow, performance-defined method for reversing pharmacologically induced mydriasis with one topical eye drop of 1% phentolamine mesylate. The patent is directed to treatment after tropicamide, phenylephrine, or both, particularly after an eye examination. Its principal limitations are the active ingredient, 1% concentration, one-drop administration, photopic pupil-reduction results, and specified tolerability outcomes.

The claims do not broadly cover every phentolamine ophthalmic product or every treatment for dilated pupils. The concentration limitation is commercially important because FDA-approved Nyxol is a 0.75% phentolamine mesylate ophthalmic solution, not the 1% dosage expressly required by claim 1.[1]

What does US Patent 12,201,615 protect?

The independent claim protects a five-part treatment protocol:

Claim element	Requirement
Patient	Human patient
Condition	Mydriasis caused by tropicamide, phenylephrine, or both
Treatment	Topical administration to the eye
Dose	One eye drop of a 1% w/w phentolamine mesylate solution
Result	At least a 30% reduction in pupil diameter under photopic conditions two hours after dosing

Claim 1 is therefore a treatment-method claim, not a composition claim. It does not independently claim the chemical compound phentolamine mesylate, the ophthalmic vehicle, container, preservative system, manufacturing process, or broad use of alpha-adrenergic antagonists.

The claim requires the recited clinical result. A product or use that satisfies the dose and disease limitations but does not produce the claimed reduction in pupil diameter would present a claim-construction and proof issue. Conversely, a product that produces the result but uses a different concentration may avoid literal infringement of claim 1.

What conditions trigger the patented method?

Claims 2 through 4 divide the causation requirement into three scenarios:

Tropicamide-induced mydriasis.
Phenylephrine-induced mydriasis.
Mydriasis caused by both drugs.

This structure tracks common ophthalmic examination practice, where tropicamide produces cycloplegia and mydriasis while phenylephrine contributes additional pupil dilation. The claims do not require that the drugs have been administered in a particular commercial formulation or dose.

The language "due to said patient having received" creates a causation limitation. The claimant would need to establish that the patient's dilation resulted from the specified mydriatic agent or agents.

How narrow is the one-drop and 1% limitation?

The one-drop and 1% limitations materially narrow the independent claim.

Claim 1 requires:

One eye drop;
A 1% w/w phentolamine mesylate solution;
Topical delivery to the patient's eye.

A regimen using two drops, a gel, an ointment, an implant, or a different volume may fall outside the literal scope. A 0.75% solution also does not literally satisfy the 1% concentration limitation.

Claim 32 further specifies that the eye drop is a liquid aqueous ophthalmic formulation. Because claim 32 depends from claim 1, it retains every limitation of claim 1 and adds the aqueous-liquid requirement. It does not broaden the patent to cover all aqueous phentolamine products.

The claims do not specify:

Drop volume;
Preservative;
Buffer;
Osmolality;
pH;
Viscosity;
Packaging;
Sterility process;
Manufacturing method;
Storage condition;
Commercial brand.

Those omissions reduce the patent's direct coverage of formulation and manufacturing design-arounds.

What performance outcomes are protected?

Claims 5 through 12 add pupil-reduction thresholds. The claim set covers both relative and absolute reductions.

Claims	Performance limitation
1	At least 30% reduction at two hours under photopic conditions
5-6	At least 1 mm reduction under photopic conditions
7-12	At least 2 mm reduction under photopic conditions
10-12	At least 2 mm reduction specifically at two hours

Claims 5 through 12 depend on claims that already require the 1% one-drop regimen. They therefore do not create independent protection for a different concentration or dosing schedule.

The claims use two different baselines:

Relative reduction compared with the patient's pupil diameter after drug-induced dilation; and
Reduction compared with the patient's pupil under the same photopic conditions without the phentolamine dose.

That baseline language may create evidentiary disputes. Pupil diameter changes with lighting, accommodation, time after mydriatic administration, age, iris pigmentation, and measurement method. A party asserting infringement would need a reproducible protocol showing the relevant baseline and photopic conditions.

What tolerability and accommodation features are protected?

Claims 13 through 17 add safety or tolerability limitations:

Eye redness increases by no more than two CCLRU grades;
No burning sensation;
Accommodation changes by at least minus one diopter relative to baseline at two hours.

These limitations may be valuable for differentiating a rapid-reversal treatment from older or less tolerable approaches. They also make infringement more fact-intensive.

CCLRU redness limitation

Claims 13 through 15 and 30 require the increase in ocular redness to be no more than two grades on the CCLRU Redness Grading Scale. The claim does not state a specific absolute redness grade. It compares the patient's post-treatment redness with the patient's pretreatment level.

No-burning limitation

Claim 16 requires that the patient experience no burning sensation from the dose. This is a subjective outcome. It may be difficult to establish across a population unless the patent's specification or clinical protocol defines the relevant observation period and assessment method.

Accommodation limitation

Claim 17 requires that, two hours after dosing, the change in accommodation be greater than or equal to -1 diopter relative to baseline. This limitation links pupil reversal with preservation of near focusing function. The claim does not require a particular accommodation test, age group, or refractive status.

What rapid-onset and post-examination uses are protected?

Claims 18 through 23 add timing and workflow limitations.

Claims 18 through 20 require a therapeutic benefit within one hour. Claims 21 through 23 require administration after completion of an eye examination in which tropicamide, phenylephrine, or both were administered.

The post-examination limitation is commercially relevant. It maps directly onto a physician-office workflow:

The patient receives a mydriatic for retinal or ocular examination.
The examination is completed.
The patient receives topical phentolamine mesylate.
The pupil returns toward baseline, potentially reducing post-examination visual impairment and light sensitivity.

Claims 21 through 23 also state that all phentolamine mesylate is administered after the examination. This language may exclude split dosing in which some phentolamine is administered before examination completion.

Does the patent cover pediatric treatment?

Yes. Claims 24 through 31 add pediatric patients to selected claim branches. Pediatric coverage includes:

Tropicamide-induced mydriasis;
Phenylephrine-induced mydriasis;
At least 1 mm or 2 mm pupil reduction;
Redness limitations;
Post-examination administration.

The pediatric claims remain dependent on the 1% one-drop regimen. They do not independently establish protection for every pediatric phentolamine treatment.

Pediatric claims may have commercial importance because pharmacologically induced mydriasis is common in pediatric ophthalmology. FDA labeling and pediatric clinical data remain separate regulatory issues from patent claim scope.[1]

What is the relationship to Nyxol and FDA regulatory status?

Nyxol is an ophthalmic phentolamine mesylate product developed by Ocuvex Therapeutics and commercialized by RVL Pharmaceuticals. FDA approved Nyxol ophthalmic solution 0.75% for reversal of pharmacologically induced mydriasis in adults.[1]

The central comparison is:

Attribute	US 12,201,615 claims	Nyxol FDA product
Active ingredient	Phentolamine mesylate	Phentolamine mesylate
Administration	Topical eye drop	Topical ophthalmic solution
Concentration	1% w/w	0.75%
Indication	Mydriasis caused by tropicamide, phenylephrine, or both	Reversal of pharmacologically induced mydriasis
Key endpoint	At least 30% pupil reduction at two hours under photopic conditions	FDA-labeled clinical reversal indication
Patient population	Human, with pediatric dependent claims	FDA approval initially directed to adults
Formulation limitation	Aqueous liquid only in claim 32	Ophthalmic solution

The shared active ingredient and therapeutic use create technical overlap. The 1% limitation, however, is a meaningful literal-scope distinction. A 0.75% commercial product does not automatically infringe a claim requiring 1% w/w.

Potential infringement theories could still involve claim construction or the doctrine of equivalents, but those issues would depend on prosecution history, the specification, claim amendments, and the technical differences between 0.75% and 1%. A concentration limitation is often vulnerable to a non-infringement argument when the accused product is materially outside the claimed range.

What patents protect phentolamine ophthalmic products?

The relevant landscape has at least four patent categories:

Method-of-use patents

These cover reversal of pharmacologically induced mydriasis, including treatment after tropicamide and phenylephrine. US 12,201,615 falls primarily in this category.

Formulation patents

Formulation claims may cover:

Phentolamine mesylate concentration;
Aqueous ophthalmic vehicles;
pH and buffering systems;
Preservatives;
Osmolality;
Stability;
Container-closure systems;
Unit-dose packaging.

The supplied claims do not contain detailed formulation limitations beyond the 1% solution and, in claim 32, the aqueous-liquid format.

Pediatric-use patents

Pediatric claims can protect age-defined use of the same ophthalmic product, particularly where the FDA label or clinical development program separates adult and pediatric populations.

Manufacturing and process patents

Process protection may cover synthesis, purification, salt formation, sterile filtration, filling, or preparation of the ophthalmic solution. No manufacturing or chemical-process limitation appears in the supplied claims.

A complete freedom-to-operate analysis would therefore require review of the entire US patent family, Orange Book listings, continuation applications, terminal disclaimers, and pending claims. The 32 claims supplied establish the scope of this patent but do not establish the full family landscape.

What is the Orange Book status of US Patent 12,201,615?

Orange Book listing depends on whether the patent claims an approved drug substance, drug product, or method of use and whether the NDA holder submitted the patent under FDA listing rules.[2]

A patent directed to a 1% method may not necessarily be listed for an NDA covering a 0.75% product. The relevant questions are:

Whether the patent claims the approved indication;
Whether the patented method is described in the approved labeling;
Whether the NDA holder submitted the patent within the statutory certification framework;
Whether FDA accepted the listing;
Whether the listed patent claims are directed to the approved product or method.

The Orange Book does not determine patent validity or infringement. It establishes the FDA patent-listing and certification framework for abbreviated new drug applications.[2]

For a generic applicant, a listed method-of-use patent could generate a Paragraph IV certification, a section viii statement for an unclaimed use, or another certification depending on the specific listing and proposed label. If the generic applicant omits the patented indication, a section viii carve-out may be available for a method-of-use patent, subject to FDA review and the patent's actual claim scope.

When does US Patent 12,201,615 lose exclusivity?

The patent's enforceable expiration date cannot be calculated from the claims alone. It depends on the patent's earliest effective nonprovisional filing date, any priority claims, patent-term adjustment, terminal disclaimer, and possible patent-term extension.

The statutory framework generally provides a 20-year term measured from the earliest effective US nonprovisional filing date, subject to adjustments and extensions.[3] Regulatory exclusivity is separate from patent term. FDA approval of Nyxol does not itself establish the expiration date of US 12,201,615.

The relevant exclusivity layers are:

Exclusivity layer	Relevance
Patent term	Determines enforceable exclusion from practicing claimed methods
Patent-term adjustment	May extend the term for USPTO delay
Patent-term extension	May apply in limited circumstances for regulatory review
New chemical entity exclusivity	FDA regulatory exclusivity, if applicable
Orphan or pediatric exclusivity	Separate statutory periods
Orange Book listing	Affects ANDA certification and potential litigation

A continuation patent can issue after approval and still have a term tied to an earlier family filing date. Grant date is not the same as expiration date.

Which companies are most exposed to this patent?

The principal commercial exposure is for companies developing generic or follow-on ophthalmic phentolamine products intended for pharmacologically induced mydriasis.

Company type	Exposure
Generic ophthalmic manufacturers	Potential Paragraph IV or label-carve-out risk
Branded phentolamine developers	Potential method and formulation overlap
Compounding pharmacies	Possible practice-of-method exposure, depending on product and use
Diagnostic ophthalmology providers	Usually lower direct risk because physicians, rather than providers, perform treatment
Pediatric ophthalmic developers	Higher exposure to claims 24-31
Alternative mydriasis-reversal developers	Design-around opportunity through active ingredient or concentration changes

The strongest direct exposure would involve a product administered exactly as claimed: one drop of 1% phentolamine mesylate after tropicamide or phenylephrine, with the claimed pupil-reduction result.

How strong is the patent estate?

US 12,201,615 has meaningful but concentrated protection.

Strengths

It targets a defined clinical use with commercial relevance.
It covers tropicamide, phenylephrine, and the combination.
It includes objective pupil-reduction thresholds.
It includes rapid-onset, post-examination, pediatric, and tolerability branches.
It may create litigation leverage if a competing product uses the same concentration and dosing protocol.

Weaknesses

The independent claim is limited to 1% w/w.
The FDA-approved Nyxol concentration is 0.75%.[1]
The claims do not broadly cover all phentolamine ophthalmic compositions.
Several dependent claims require subjective or protocol-sensitive outcomes.
Method claims require proof of administration and patient-specific clinical facts.
Performance limitations may create disputes over photopic testing and baseline selection.

The patent is stronger as a targeted blocking right against an exact 1% regimen than as a broad barrier to all phentolamine-based mydriasis-reversal products.

What generic launch scenarios exist?

Scenario 1: Exact 1% product

A generic 1% phentolamine mesylate eye drop used for the claimed indication would face the highest infringement risk. A Paragraph IV challenge could trigger patent litigation and a possible 30-month stay if the statutory conditions are met.[2]

Scenario 2: 0.75% product

A 0.75% product has a substantial literal non-infringement argument against claim 1 because it does not meet the 1% limitation. Other Orange Book-listed patents, formulation claims, or related family members could still create barriers.

Scenario 3: Different dosing schedule

A two-drop regimen, split dosing, or administration at a different stage of the examination could avoid particular limitations. It may not avoid broader family claims, if any exist.

Scenario 4: Label carve-out

A generic applicant could seek approval for uses that omit the patented method, depending on the approved labeling and the scope of the listed patent. FDA approval, however, would not authorize promotional activity for the carved-out indication.[2]

Scenario 5: Alternative active ingredient

An alpha-adrenergic antagonist other than phentolamine mesylate would generally fall outside these claims, although separate patents could cover the alternative compound or treatment method.

What litigation and licensing issues matter?

The key litigation questions would be:

Whether 1% means exactly 1% or includes a tolerated manufacturing range.
Whether the accused product is administered as one eye drop.
Whether the patient's mydriasis was caused by the claimed mydriatic.
Whether the claimed photopic pupil-reduction result is inherent in use of the product.
Whether clinical performance must be shown in every patient or only in representative use.
Whether prosecution history limits reliance on equivalents.
Whether the patent is subject to a terminal disclaimer or overlapping family term.

Licensing value is highest where a licensee wants the exact 1% regimen, pediatric positioning, or a post-examination treatment protocol. The license value is lower for a product deliberately designed around 0.75%, a different dose, or a different active ingredient.

Key Takeaways

US 12,201,615 is a narrow method-of-use patent for reversing tropicamide- or phenylephrine-induced mydriasis.
Claim 1 requires one topical eye drop of a 1% w/w phentolamine mesylate solution.
The claim also requires at least a 30% pupil reduction at two hours under photopic conditions.
Dependent claims add 1 mm and 2 mm pupil reductions, rapid onset, redness limits, lack of burning, accommodation preservation, post-examination administration, pediatric patients, and aqueous formulation.
FDA-approved Nyxol is a 0.75% phentolamine mesylate ophthalmic solution, creating a significant concentration-based design-around issue.[1]
The patent does not broadly claim phentolamine ophthalmic compositions, manufacturing processes, or every mydriasis-reversal use.
Exact 1% generic products face the greatest infringement and Paragraph IV risk.
A 0.75% product may avoid literal infringement of the supplied claims but remains subject to other patents, Orange Book listings, and equivalence arguments.
Patent expiration requires review of the family’s priority data, patent-term adjustment, terminal disclaimers, and any patent-term extension.
The patent is commercially stronger as a targeted method claim than as a comprehensive barrier to the phentolamine ophthalmic market.

FAQs

Does US Patent 12,201,615 cover Nyxol directly?

It covers a 1% phentolamine mesylate regimen. Nyxol is an FDA-approved 0.75% product, so the concentration difference is central to any infringement analysis.[1]

Can a generic avoid the patent by using 0.75% phentolamine?

A 0.75% product has a strong literal non-infringement position against a claim requiring 1% w/w. Other patents and the doctrine of equivalents remain separate issues.

Does the patent cover dilation caused only by phenylephrine?

Yes. Claim 3 expressly covers mydriasis caused by phenylephrine.

Are pediatric patients covered?

Yes. Claims 24 through 31 extend selected treatment, performance, tolerability, and post-examination limitations to pediatric human patients.

Is a 1% phentolamine formulation itself patented?

The supplied claims do not claim the formulation as a composition of matter. They claim its use in a defined method for treating pharmacologically induced mydriasis.

References

U.S. Food and Drug Administration. (2023). Nyxol (phentolamine mesylate ophthalmic solution) prescribing information. FDA.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.
United States Patent and Trademark Office. (2024). Patent term and adjustment information. USPTO.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Famygen Life Sci	RYZUMVI	phentolamine mesylate	SOLUTION;OPHTHALMIC	217064-001	Sep 25, 2023		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial				TREATMENT OF PHARMACOLOGICALLY-INDUCED MYDRIASIS	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2019366451	⤷ Start Trial
Australia	2024219970	⤷ Start Trial
Brazil	112021007725	⤷ Start Trial
Canada	3116589	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Summary for Patent: 12,201,615