List of Excipients in Branded Drug RHOPRESSA

« Back to Dashboard

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Alcon Laboratories Inc	RHOPRESSA	netarsudil	70727-497	BENZALKONIUM CHLORIDE	2034-03-14
Alcon Laboratories Inc	RHOPRESSA	netarsudil	70727-497	BORIC ACID	2034-03-14
Alcon Laboratories Inc	RHOPRESSA	netarsudil	70727-497	MANNITOL	2034-03-14
Alcon Laboratories Inc	RHOPRESSA	netarsudil	70727-497	SODIUM HYDROXIDE	2034-03-14
Alcon Laboratories Inc	RHOPRESSA	netarsudil	70727-497	WATER	2034-03-14

Last updated: September 5, 2026

Rhopressa’s commercial opportunity is concentrated in formulation engineering rather than new active-ingredient discovery. The product is a once-daily, preserved ophthalmic solution containing netarsudil 0.02%, with a relatively simple excipient system that creates opportunities for preservative-free delivery, improved tolerability, longer shelf life, packaging differentiation, and generic substitution. The main barriers are ophthalmic product equivalence, container-closure performance, microbial control, and the need to demonstrate comparable clinical and physicochemical performance.

Rhopressa Excipient Strategy, Formulation Patents, and Commercial Opportunities

What is Rhopressa and how is it formulated?

Rhopressa is the U.S. brand name for netarsudil ophthalmic solution 0.02%, marketed for reduction of elevated intraocular pressure in patients with primary open-angle glaucoma or ocular hypertension. The product was approved by the U.S. Food and Drug Administration in December 2017 and was developed by Aerie Pharmaceuticals. Alcon acquired Aerie in 2019 and obtained the Rhopressa and Rocklatan commercial franchises.[1,2]

Rhopressa is administered as one drop in the affected eye once daily in the evening. Its active pharmaceutical ingredient is netarsudil, supplied as netarsudil dimesylate.

Product attribute	Rhopressa specification
Active ingredient	Netarsudil dimesylate
Strength	Equivalent to netarsudil 0.02%
Dosage form	Ophthalmic solution
Route	Topical ocular
Dosing	One drop once daily in the evening
Preservative	Benzalkonium chloride 0.015%
Other listed excipients	Boric acid, mannitol, sodium hydroxide, purified water
Indications	Primary open-angle glaucoma and ocular hypertension
FDA approval	December 2017
Current commercial owner	Alcon, following acquisition of Aerie Pharmaceuticals

The formulation is aqueous and contains benzalkonium chloride, or BAK, as both a preservative and a potential source of formulation and tolerability constraints. Boric acid contributes to buffering and tonicity control. Mannitol contributes to osmolality. Sodium hydroxide is used for pH adjustment.[1]

What excipients are used in Rhopressa?

Rhopressa uses a short excipient list:

1. Benzalkonium chloride at 0.015%.
2. Boric acid.
3. Mannitol.
4. Sodium hydroxide.
5. Purified water.

The formulation’s commercial advantages are manufacturing simplicity, low excipient burden, and compatibility with a multidose ophthalmic bottle. Its limitations include BAK exposure, sensitivity to pH and osmolality, and the need to maintain netarsudil solubility and chemical stability over the product shelf life.

What role does benzalkonium chloride play?

BAK is the principal commercial target for reformulation. It provides antimicrobial preservation in a multidose container, but chronic exposure can contribute to ocular-surface irritation, tear-film instability, epithelial toxicity, and reduced tolerability in some patients. These effects are relevant in glaucoma because treatment is often long term and patients may use multiple preserved ophthalmic products.[3]

A BAK-free Rhopressa product could target:

• Patients with ocular-surface disease.
• Patients receiving multiple glaucoma medications.
• Patients with preservative intolerance.
• Prescribers seeking lower preservative burden.
• Premium pharmacy and specialty distribution channels.
• Fixed-combination or co-packaged glaucoma regimens.

Removing BAK is not a simple substitution. A reformulated product must preserve antimicrobial quality throughout in-use storage, demonstrate container compatibility, maintain drop delivery, and satisfy preservative efficacy requirements under applicable FDA and USP standards.

What role do boric acid and mannitol play?

Boric acid and mannitol are functional excipients rather than major differentiation assets. Boric acid supports buffer capacity and formulation control. Mannitol contributes to tonicity and may help produce an ocularly acceptable osmolality.

A reformulator could investigate alternative buffering and tonicity systems, but changes would need to avoid:

• Reduced netarsudil solubility.
• Increased degradation.
• Ocular irritation.
• Precipitation during storage.
• Changes in viscosity or drop size.
• Altered drug release from the tear film.

The commercial value of replacing boric acid or mannitol is lower than the value of developing a BAK-free or preservative-free presentation. These excipients may still matter in a patent strategy when they are tied to a narrow pH range, stability profile, or packaging system.

What excipient strategies could improve Rhopressa?

The highest-value formulation strategies are preservative reduction, preservative elimination, improved ocular residence, and packaging redesign.

Preservative-free multidose delivery

Preservative-free multidose bottles use one-way valves, airless systems, antimicrobial bottle components, or mechanical designs that limit microbial ingress. These systems can support a premium product but introduce higher component costs and more complex device validation.

A preservative-free Rhopressa could compete on tolerability rather than price. The commercial proposition would be strongest in chronic-use patients and in markets where preservative-free glaucoma products have established reimbursement pathways.

Alternative preservatives

Potential alternatives include oxidative systems, polyquaternium-based systems, stabilized oxychloro complexes, and other low-irritancy preservative approaches. Each option presents a different regulatory and technical profile.

The main challenge is that the alternative must be compatible with:

• Netarsudil dimesylate.
• The formulation pH.
• The bottle and closure system.
• Long-term storage.
• In-use microbial protection.
• Ocular tissue tolerability.

An alternative preservative may avoid direct BAK patent claims, but it may create new regulatory work and may not deliver a clinically meaningful benefit unless tolerability is improved.

Unit-dose packaging

Single-use vials can eliminate the need for a conventional preservative. They may also reduce contamination risk and support hospital, surgical, and high-risk ocular-surface use.

The disadvantages are higher packaging costs, greater material consumption, lower convenience, and more demanding filling operations. Unit-dose packaging could be attractive for a premium line but is less likely to replace a low-cost generic multidose product.

Increased viscosity and ocular residence

A modest increase in viscosity may improve ocular residence and reduce drainage through the nasolacrimal system. Candidate excipients include cellulose derivatives, polyvinyl alcohol, polyvinylpyrrolidone, carbomers, and other ophthalmic viscosity modifiers.

This strategy has to balance retention against blurred vision, dropper performance, comfort, and dose reproducibility. Higher viscosity may also change the perceived drop size and expose the product to a different bioequivalence profile.

Solubility and stability optimization

Netarsudil formulation work can focus on:

• pH optimization.
• Salt selection.
• Buffer concentration.
• Chelating agents.
• Antioxidants.
• Light protection.
• Low-adsorption packaging.
• Reduced headspace oxygen.
• Improved freeze-thaw stability.

These changes may support a new patent position even where the active ingredient and nominal strength remain unchanged. The most defensible claims generally combine composition and performance limitations, such as a defined pH range with improved stability or reduced degradation.

What formulation patents could protect a Rhopressa lifecycle product?

Formulation patents could cover the composition, container, dosing system, manufacturing process, or therapeutic use. The strongest commercial claims usually connect a formulation feature to a measurable product benefit.

Potential patent claim categories

Patent category	Potential subject matter	Commercial purpose
Composition	Netarsudil with a defined buffer, tonicity agent, preservative, or pH range	Protects reformulated product
Preservative-free formulation	Netarsudil solution in a sterile multidose or unit-dose system	Supports premium and tolerability positioning
Container closure	Airless bottle, valve, pump, or low-adsorption material	Creates device and packaging exclusivity
Stability	Reduced degradation under light, heat, or long-term storage	Supports extended shelf life
Viscosity	Defined rheology or residence-enhancing excipient	Differentiates administration and retention
Manufacturing	Sterile filtration, filling, or control of particulate matter	Creates process barriers
Method of use	Use in patients with ocular-surface disease or preservative intolerance	Extends clinical positioning
Combination product	Netarsudil with another glaucoma active	Supports fixed-dose competition with Rocklatan

A patent directed only to a conventional excipient substitution may be vulnerable if the change is predictable and lacks unexpected results. Data showing improved ocular-surface tolerability, better stability, lower dosing variability, or a clinically relevant adherence benefit can improve enforceability and licensing value.

When does Rhopressa lose exclusivity?

Rhopressa’s regulatory exclusivity and patent exclusivity are separate.

The product received FDA approval in December 2017. A new chemical entity generally receives five years of FDA exclusivity, subject to statutory provisions governing abbreviated new drug applications. The five-year period would have run from the original approval date, while patent rights could extend beyond that period depending on issued claims and patent-term adjustment or extension.[4]

The precise generic-entry date depends on:

• Orange Book-listed patents.
• Patent expiration dates.
• Any pediatric exclusivity.
• Paragraph IV certifications.
• Litigation and a possible 30-month stay.
• Settlement agreements.
• Regulatory approval timing.
• The generic applicant’s ability to establish pharmaceutical equivalence and bioequivalence.

Because Rhopressa is a small-molecule ophthalmic solution, biosimilar competition is not the relevant pathway. Competition would normally arise through an ANDA, with applicants addressing listed patents through Paragraph I, II, III, or IV certifications.

What is the Orange Book status of Rhopressa?

Rhopressa is an FDA-approved small-molecule drug product and is eligible for Orange Book listing of patents that claim the drug substance, drug product, or approved method of use. The practical significance of the Orange Book is that listed patents can require patent certifications from ANDA applicants.[4]

The principal legal questions for a generic applicant are:

• Whether any listed patent claims netarsudil dimesylate.
• Whether any listed patent claims the ophthalmic solution.
• Whether method-of-use claims are relevant to the proposed label.
• Whether the applicant can file a Paragraph IV certification.
• Whether the patent holder sues within 45 days.
• Whether litigation triggers a statutory 30-month stay.

A generic applicant may use a “skinny label” strategy to omit patented indications or dosing instructions, but the commercial value depends on whether the remaining label supports a viable market.

Which companies are likely to challenge Rhopressa?

The likely challengers are established generic ophthalmic companies with sterile-liquid manufacturing capacity. Relevant competitive categories include:

• Large generic manufacturers with ophthalmic ANDA platforms.
• Specialty ophthalmic companies.
• Contract manufacturers with sterile fill-finish capability.
• Companies already marketing glaucoma solutions.
• Firms pursuing preservative-free or advanced multidose delivery.

The technical hurdle is higher than for a conventional oral tablet. An ANDA applicant must match the reference product’s active ingredient, strength, dosage form, route, quality attributes, and container-closure performance. Ophthalmic products also require tight control of sterility, particulate matter, pH, osmolality, viscosity, drop size, and extractables and leachables.

How strong is the Rhopressa patent estate?

The commercial strength of the Rhopressa estate depends less on the number of patents than on claim coverage across several layers:

1. Netarsudil composition-of-matter rights.
2. Salt and crystalline-form claims.
3. Ophthalmic formulation claims.
4. Method-of-use claims.
5. Combination-product claims covering Rocklatan.
6. Container and delivery-device claims.
7. Manufacturing and stability claims.

Composition-of-matter patents generally provide the strongest exclusion if still enforceable. Formulation patents can preserve market share after active-ingredient protection ends, but their value depends on whether the generic can design around them while maintaining an approvable product.

A BAK-free reformulation could create a new patent estate with a later expiration date than the original active-ingredient patents. It could also reduce direct substitutability if the product is positioned as a clinically differentiated presentation rather than as a conventional generic.

What commercial opportunities exist for excipient suppliers and CDMOs?

The most attractive opportunities are not commodity excipient sales. They are integrated formulation and delivery programs.

Excipient suppliers

Suppliers can pursue:

• Low-irritancy preservative systems.
• Ophthalmic-grade viscosity modifiers.
• Low-endotoxin and low-bioburden excipients.
• Packaging-compatible antioxidants and chelators.
• Excipient combinations with established ophthalmic regulatory histories.
• Technical packages supporting novel ophthalmic excipient use.

The strongest value proposition combines excipient supply with formulation development, stability data, regulatory support, and compatibility testing.

CDMOs

CDMOs with sterile ophthalmic capabilities can offer:

• Aseptic filling.
• Blow-fill-seal production.
• Unit-dose vial manufacturing.
• Preservative-free multidose packaging.
• Sterility assurance programs.
• Container-closure integrity testing.
• Extractables and leachables studies.
• Stability and in-use testing.

A CDMO that can manufacture both standard multidose and preservative-free presentations could support lifecycle products, authorized generics, and regional licensing programs.

How does Rhopressa compare with Rocklatan and generic glaucoma products?

Rocklatan combines netarsudil with latanoprost. It offers a broader pharmacologic mechanism but has a more complex formulation and combination-product patent profile. Rhopressa is simpler to manufacture and may be easier to reformulate as a preservative-free or low-preservative product.

Product	Active ingredients	Formulation opportunity	Competitive issue
Rhopressa	Netarsudil	BAK-free delivery, viscosity, packaging	Generic netarsudil solution
Rocklatan	Netarsudil and latanoprost	Combination stability and packaging	Fixed-dose combination patents
Latanoprost generics	Latanoprost	Preservative-free and multidose systems	Heavy price competition
Timolol combinations	Timolol plus another active	Device and preservative differentiation	Mature generic market
Prostaglandin analogs	Various	Ocular-surface tolerability	Broad established competition

Rhopressa’s best premium opportunity is a formulation that improves tolerability or adherence without materially increasing dosing complexity.

What generic launch risks exist for Rhopressa?

The generic launch risk is moderate to high after relevant patent barriers expire or become vulnerable. The market is attractive because glaucoma treatment is chronic, but price erosion can be substantial once multiple ANDA products enter.

Key risk factors include:

• Multiple potential sterile-ophthalmic manufacturers.
• Limited differentiation for a conventional preserved solution.
• Substitution pressure from pharmacy benefit managers.
• Physician familiarity with established glaucoma products.
• Potential competition from generic Rocklatan or other combination products.
• Difficulty sustaining premium pricing without clinical or tolerability advantages.

The strongest defense is a differentiated product with a defensible formulation patent, a distinct package, and evidence supporting use in patients who cannot tolerate BAK-containing products.

Key Takeaways

• Rhopressa contains netarsudil 0.02% in a relatively simple preserved ophthalmic solution.
• Benzalkonium chloride is the clearest target for lifecycle reformulation.
• BAK-free multidose, unit-dose, and low-irritancy preservative systems offer the largest commercial opportunities.
• The relevant generic pathway is an ANDA, not a biosimilar application.
• Formulation patents are most valuable when tied to stability, tolerability, delivery, or packaging performance.
• Generic entry depends on Orange Book patents, Paragraph IV activity, litigation, settlements, and FDA approval timing.
• Excipient suppliers and CDMOs can capture greater value through integrated ophthalmic development rather than commodity excipient supply.
• A premium reformulation must establish a measurable advantage over the existing Rhopressa solution.

FAQs

Can Rhopressa be reformulated without benzalkonium chloride?

Yes. A preservative-free Rhopressa could use unit-dose packaging or a validated multidose delivery system that prevents microbial contamination. The reformulation would require new stability, sterility, container-closure, in-use, and preservative-effectiveness data.

Is netarsudil suitable for a fixed-dose combination product?

Yes. Rocklatan already combines netarsudil with latanoprost. Additional combinations would require compatibility, stability, dosing, clinical, and intellectual-property analysis.

What is the most valuable Rhopressa excipient innovation?

A preservative-free multidose system paired with demonstrated ocular-surface tolerability is likely to have the highest commercial value. A conventional buffer or tonicity substitution is less differentiated.

Can a generic company avoid Rhopressa formulation patents?

Potentially. An ANDA applicant may design around formulation, packaging, or method-of-use claims, provided the alternative product meets FDA requirements and does not infringe enforceable claims.

Are ophthalmic excipients subject to special manufacturing requirements?

Yes. Ophthalmic products require controls for sterility, particulate matter, endotoxins, microbial contamination, container-closure integrity, and extractables and leachables. Excipient quality must be assessed within the finished sterile product rather than solely on compendial identity.

References

1. U.S. Food and Drug Administration. (2017). Rhopressa (netarsudil ophthalmic solution) prescribing information. FDA.

2. Alcon Inc. (2019). Alcon completes acquisition of Aerie Pharmaceuticals. Alcon corporate information.

3. U.S. Food and Drug Administration. (2019). Ophthalmic drug products for topical administration: Quality considerations. FDA.

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA.