List of Excipients in Branded Drug AZOPT

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Alcon Laboratories Inc	AZOPT	brinzolamide	0065-0275	BENZALKONIUM CHLORIDE
Alcon Laboratories Inc	AZOPT	brinzolamide	0065-0275	CARBOMER HOMOPOLYMER TYPE C
Alcon Laboratories Inc	AZOPT	brinzolamide	0065-0275	EDETATE DISODIUM
Alcon Laboratories Inc	AZOPT	brinzolamide	0065-0275	HYDROCHLORIC ACID

AZOPT Excipient Strategy and Commercial Opportunities for Brinzolamide Ophthalmic Suspension

Last updated: October 5, 2026

AZOPT is a preserved, multidose ophthalmic suspension containing brinzolamide 1%, a carbonic anhydrase inhibitor used to reduce elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension. Its excipient system is central to product performance because brinzolamide has limited aqueous solubility and is delivered as a suspension rather than a clear solution.

The strongest commercial opportunities are preservative-free unit-dose products, improved suspension uniformity, lower-blur formulations, combination products, and differentiated multidose delivery systems. Conventional generic substitution is established, so a new product needs a measurable advantage in tolerability, adherence, administration, or device performance.

What excipients are in AZOPT?

AZOPT contains a suspension, buffering, tonicity, viscosity, wetting, chelating, preservative, and pH-adjustment system.

Component	Function in AZOPT
Brinzolamide	Active carbonic anhydrase inhibitor
Mannitol	Tonicity adjustment and formulation stabilizer
Carbomer 974P	Suspending and viscosity-enhancing polymer
Tyloxapol	Nonionic wetting and dispersing surfactant
Edetate disodium	Chelating agent that binds trace metals
Sodium chloride	Tonicity adjustment
Benzalkonium chloride	Multidose preservative
Hydrochloric acid and/or sodium hydroxide	pH adjustment
Purified water	Vehicle

The product is supplied as a white-to-off-white suspension. The label instructs patients to shake the bottle well before use, reflecting the formulation’s dispersed-particle design rather than a fully dissolved drug system (Novartis Pharmaceuticals Corporation, 2011).

Why does AZOPT require a suspension?

Brinzolamide is poorly soluble in water at concentrations needed for ophthalmic dosing. A suspension permits a 1% drug concentration without relying on a high level of cosolvent or extreme pH. The trade-off is that the manufacturer must control particle size, sedimentation, redispersibility, viscosity, dose uniformity, and ocular comfort.

For a generic or follow-on product, sameness of active ingredient alone is insufficient commercially. The product must provide reproducible dosing after storage, shipping, bottle inversion, and repeated use.

How does the AZOPT excipient system work?

AZOPT uses a polymer-surfactant suspension platform.

Carbomer 974P

Carbomer 974P increases viscosity and reduces the rate at which brinzolamide particles settle. Excessive viscosity, however, can produce poor drop formation, prolonged blurred vision, and difficult bottle dispensing. The polymer must be hydrated and neutralized consistently because small process changes can alter rheology.

Tyloxapol

Tyloxapol improves wetting of brinzolamide particles and helps prevent aggregation during manufacture and storage. Its commercial value is linked to particle dispersion and redispersibility. A replacement surfactant would need to preserve suspension quality without increasing irritation, foaming, extractables, or regulatory complexity.

Mannitol and sodium chloride

Mannitol and sodium chloride contribute to tonicity. Their combined use gives the formulator flexibility to control osmolality while avoiding dependence on sodium chloride alone. Tonicity must be balanced against drug solubility, suspension stability, ocular comfort, and pH.

Edetate disodium

Edetate disodium limits the impact of trace metal ions that can catalyze degradation or destabilize excipients. It also supports preservative performance in some formulations. Its concentration must remain compatible with ocular tolerance and the overall preservative strategy.

Benzalkonium chloride

Benzalkonium chloride, or BAK, permits repeated use from a multidose bottle. The same preservative creates a differentiation opportunity because chronic ophthalmic exposure to BAK is associated with ocular-surface tolerability concerns, particularly in patients using multiple glaucoma products or having pre-existing dry-eye disease (European Medicines Agency, 2009).

What formulation patents protect AZOPT?

AZOPT’s historical protection was directed primarily to brinzolamide ophthalmic compositions and their use in lowering intraocular pressure. The relevant protection categories include:

1. Brinzolamide ophthalmic suspensions.
2. Stabilized aqueous formulations.
3. Methods of treating glaucoma or ocular hypertension.
4. Particle dispersion and dosage uniformity.
5. Potential combination use with other intraocular-pressure-lowering therapies.

The original AZOPT product is a small-molecule ophthalmic drug, not a biologic. Biosimilar regulation therefore does not apply. Follow-on products generally enter through the abbreviated new drug application pathway, subject to applicable patent certifications and FDA requirements.

A current commercial review should distinguish three types of protection:

Protection category	Relevance to AZOPT
Orange Book-listed patents	May affect ANDA certification and launch timing
Unlisted formulation or process patents	May create litigation or manufacturing risk but may not block FDA approval
Trade secrets	May protect particle engineering, mixing order, process controls, and scale-up knowledge

The existence of an old composition patent does not by itself establish a current barrier to generic entry. The practical question is whether a live, enforceable patent is listed or can support an infringement action against a proposed product.

When did AZOPT lose exclusivity?

AZOPT’s original regulatory exclusivity and core patent protection have expired, allowing generic brinzolamide ophthalmic suspension products to enter the U.S. market. FDA approved AZOPT in 1998 under NDA 020816 (U.S. Food and Drug Administration, 1998).

Because the product is an older small-molecule ophthalmic drug, the commercial market is primarily a generic market rather than an originator-exclusivity market. Current launch risk depends more on formulation development, manufacturing capacity, supply reliability, payer contracting, and device differentiation than on the original AZOPT exclusivity period.

What is the Orange Book status of AZOPT?

The Orange Book is the controlling FDA source for current listed patents, therapeutic equivalence evaluations, and application information. AZOPT is listed as a brinzolamide ophthalmic suspension under NDA 020816. Authorized and independent generic products may be listed under separate abbreviated applications.

For commercial diligence, the key Orange Book questions are:

• Whether any patent remains listed against NDA 020816.
• Whether the relevant patent has an expiration date that affects a proposed ANDA.
• Whether a generic has an AB therapeutic-equivalence rating.
• Whether a product is approved as a suspension with the same strength and route.
• Whether any patent dispute or 30-month stay affects a specific ANDA.

Generic approval does not guarantee immediate market access. A Paragraph IV certification can trigger patent litigation and, in some cases, a 30-month statutory stay under the Hatch-Waxman Act. For an older product such as AZOPT, the largest Paragraph IV risk generally arises from a new formulation, device, or combination patent rather than from the original product patent estate.

Which companies are challenging AZOPT?

The relevant competitive group includes generic ophthalmic manufacturers and branded glaucoma companies. Generic manufacturers can compete through conventional brinzolamide 1% suspension products. Branded companies compete through alternative carbonic anhydrase inhibitors, prostaglandin analogues, beta blockers, alpha agonists, and fixed-combination products.

The main product classes are:

Product class	Examples	Commercial relevance
Brinzolamide	AZOPT and generic brinzolamide 1% suspensions	Direct substitution
Dorzolamide	Trusopt and generics	Same therapeutic class, different formulation profile
Brinzolamide/timolol	Simbrinza	Combination-product competition
Dorzolamide/timolol	Cosopt and generics	Established fixed-combination alternative
Prostaglandin analogues	Latanoprost, bimatoprost, travoprost	Often used as first-line therapy
Preservative-free glaucoma products	Various branded and generic platforms	Ocular-surface differentiation

The main commercial threat to a conventional AZOPT generic is not only another brinzolamide product. It is substitution by a lower-cost fixed combination or a better-tolerated preservative-free product.

What commercial opportunities exist for AZOPT formulations?

Preservative-free brinzolamide

A preservative-free product is the clearest formulation opportunity. It could be delivered in unit-dose containers or in a multidose bottle with a preservative-free valve system.

Potential advantages include:

• Reduced chronic BAK exposure.
• Positioning for patients with ocular-surface disease.
• Greater suitability for patients using multiple topical therapies.
• Differentiation in ophthalmology channels.
• Potential premium pricing relative to standard generic suspension.

The principal technical barriers are microbial control, container closure integrity, dose withdrawal, suspension redispersion, and manufacturing cost.

Improved multidose delivery

A preservative-free multidose bottle could offer better adherence than unit-dose packaging by reducing opening frequency and waste. The device would need to prevent microbial ingress without relying on BAK.

Patentable elements may include:

• One-way valves.
• Airless dispensing systems.
• Metered-dose actuators.
• In-bottle suspension mixing or controlled inversion.
• Low-residual-volume containers.
• Materials compatible with brinzolamide and the excipient system.

Device protection could extend the commercial life of a formulation after core drug patents have expired.

Lower-blur suspension

Ophthalmic suspensions can temporarily blur vision. A product with narrower particle-size distribution, lower viscosity, improved wetting, or faster ocular dispersion could be positioned around administration comfort.

A credible development program would measure:

• D50 and D90 particle size.
• Sedimentation volume.
• Redispersibility after defined settling periods.
• Drop size and delivered dose.
• In vitro release.
• Visual acuity recovery after dosing.
• Ocular surface tolerability.

Enhanced adherence formulations

A once-daily brinzolamide product would be commercially attractive, but it would require meaningful pharmacokinetic, pharmacodynamic, and clinical support. Possible approaches include mucoadhesive systems, in situ gels, controlled-release particles, or drug-device combinations.

These approaches carry higher regulatory risk because changes in residence time and exposure may require clinical bridging beyond conventional ANDA expectations.

Fixed-combination products

Brinzolamide can be paired with agents that act through different mechanisms, including beta blockers or alpha agonists. AZOPT’s commercial precedent is Simbrinza, a brinzolamide/brimonidine tartrate fixed combination approved for elevated intraocular pressure (Novartis Pharmaceuticals Corporation, 2013).

A generic fixed combination can reduce bottle burden and improve adherence. Its principal challenges are chemical compatibility, preservative load, dose uniformity for two suspended or dissolved actives, and separate patent positions covering the combination or method of use.

How strong is the AZOPT patent estate?

The legacy AZOPT patent estate is commercially weaker than a current branded product estate because the product has been marketed for more than two decades and generic competition exists. The remaining value is more likely to reside in narrow formulation, device, manufacturing, or combination patents than in broad protection for brinzolamide ophthalmic use.

Asset type	Relative strategic value
Original brinzolamide composition claims	Low after expiration
Broad ophthalmic-use claims	Low to moderate, depending on status
Particle-size and suspension claims	Moderate if clinically linked to performance
Preservative-free formulations	Moderate to high
Multidose delivery devices	Moderate to high
Fixed-combination formulations	Moderate
Manufacturing process controls	High as trade secrets, lower as stand-alone patents unless narrowly claimed

The strongest defensible strategy would combine formulation claims, device claims, process claims, and clinical evidence showing improved tolerability or adherence.

What manufacturing and intellectual-property barriers exist?

Manufacturing a robust ophthalmic suspension requires control over particle size, wetting, polymer hydration, microbial bioburden, filling accuracy, and container compatibility.

Key barriers include:

• Reproducible brinzolamide micronization.
• Prevention of hard sediment or caking.
• Consistent carbomer hydration.
• Uniform surfactant distribution.
• Control of viscosity across shelf life.
• Low-shear filling without dose segregation.
• Compatibility between BAK and packaging materials.
• Sterile processing and validated hold times.
• Accurate dose delivery after prolonged storage.

Process know-how can create a meaningful barrier even when the product composition is not strongly protected. A competitor may obtain approval but face higher reject rates, slower scale-up, or greater stability risk.

What generic launch scenarios exist?

Standard generic launch

A conventional brinzolamide 1% suspension competes on price, wholesaler access, supply reliability, and therapeutic-equivalence status. This is the lowest-risk development path but usually has limited pricing power.

Authorized-generic or branded-generic launch

An originator-linked or branded-generic product can use existing manufacturing know-how and commercial relationships. The opportunity depends on channel strategy and the ability to maintain supply without incurring full branded operating costs.

Preservative-free premium launch

This strategy targets ocular-surface sensitivity and chronic-use patients. It has greater formulation and device complexity but can support higher net pricing.

Fixed-combination launch

A brinzolamide combination product reduces administration burden and may compete against established products such as Cosopt and Simbrinza. Patent and clinical-development requirements are more complex than for a single-agent generic.

Geographic expansion

Outside the United States, opportunity depends on local registration, reference-product requirements, preservative restrictions, tender systems, and ophthalmology reimbursement. Markets with high generic penetration favor low-cost standard suspensions. Markets with stronger demand for preservative-free therapy may support differentiated products.

What regulatory pathway applies to AZOPT follow-on products?

A conventional brinzolamide ophthalmic suspension is generally suited to an ANDA if the applicant can demonstrate pharmaceutical equivalence and bioequivalence through FDA-accepted ophthalmic product requirements. A materially different formulation, delivery system, or clinical claim may require a 505(b)(2) application.

The regulatory pathway affects commercial timing:

Product concept	Likely pathway pressure
Same strength, route, dosage form, and active ingredient	ANDA-oriented
Preservative-free version with otherwise comparable design	ANDA or 505(b)(2), depending on differences
New multidose device	Device and formulation bridging required
Sustained-release or mucoadhesive system	Likely higher 505(b)(2) burden
New fixed combination	Combination-product regulatory requirements
New method-of-use claim	Patent and labeling strategy required

Key Takeaways

• AZOPT is a brinzolamide 1% ophthalmic suspension with mannitol, carbomer 974P, tyloxapol, edetate disodium, sodium chloride, BAK, pH adjusters, and water.
• Carbomer and tyloxapol are central to suspension stability, redispersion, and dose uniformity.
• The original AZOPT exclusivity period has expired, and conventional generic competition is established.
• Biosimilar risk does not apply because brinzolamide is a small molecule.
• The strongest commercial opportunities are preservative-free delivery, improved multidose devices, lower-blur suspensions, and fixed combinations.
• The most defensible new intellectual property would combine formulation, device, process, and clinically supported tolerability claims.
• Standard generic entry is low risk but price competitive. Differentiated products require stronger manufacturing and regulatory execution.

FAQs About AZOPT Excipient Strategy and Commercial Opportunities

Is benzalkonium chloride necessary in AZOPT?

BAK is used to preserve the multidose AZOPT bottle. It is not necessary for a product using unit-dose packaging or a validated preservative-free multidose device.

Can carbomer 974P be replaced in a generic brinzolamide suspension?

Yes, but replacement requires demonstration of equivalent suspension performance, delivered dose, stability, redispersibility, ocular tolerability, and regulatory comparability.

Is preservative-free brinzolamide commercially attractive?

Yes. It can target chronic glaucoma patients with ocular-surface disease, but packaging and microbial-control costs are higher than for a conventional BAK-preserved bottle.

Does AZOPT have biosimilar competition?

No. Brinzolamide is a small-molecule active ingredient. Follow-on products are generally evaluated through generic-drug pathways rather than biosimilar pathways.

What is the highest-value patent opportunity for a new brinzolamide product?

A clinically differentiated preservative-free formulation or multidose delivery system is likely to provide more commercial value than a broad claim directed only to brinzolamide ophthalmic use.

References

European Medicines Agency. (2009). Questions and answers on benzalkonium chloride used as an excipient in medicinal products for human use. https://www.ema.europa.eu/

Novartis Pharmaceuticals Corporation. (2011). AZOPT (brinzolamide ophthalmic suspension) prescribing information. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/

Novartis Pharmaceuticals Corporation. (2013). SIMBRINZA (brinzolamide and brimonidine tartrate ophthalmic suspension) prescribing information. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/

U.S. Food and Drug Administration. (1998). AZOPT NDA 020816 approval information. https://www.accessdata.fda.gov/

U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book-data-files/