List of Excipients in Branded Drug PAZEO

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Alcon Laboratories Inc	PAZEO	olopatadine hydrochloride	0065-4273	BENZALKONIUM CHLORIDE
Alcon Laboratories Inc	PAZEO	olopatadine hydrochloride	0065-4273	BORIC ACID
Alcon Laboratories Inc	PAZEO	olopatadine hydrochloride	0065-4273	HYDROCHLORIC ACID

PAZEO Excipient Strategy and Commercial Opportunities for Olopatadine Ophthalmic Solution

Last updated: September 24, 2026

PAZEO is a once-daily olopatadine hydrochloride ophthalmic solution containing 0.7% olopatadine, equivalent to 0.665% olopatadine base. Its formulation uses benzalkonium chloride, phosphate buffering, sodium chloride, purified water, and pH adjustment. The commercial opportunity is strongest in preservative-free allergy products, multidose delivery systems, regional generic supply, and differentiated formulations that reduce ocular-surface exposure to benzalkonium chloride while preserving once-daily dosing.

PAZEO’s main commercial constraint is that its active ingredient is mature and widely available through the Pataday franchise and generic olopatadine products. New entrants therefore need to compete through excipient tolerability, device convenience, pricing, geographic access, or specialty-channel positioning rather than active-ingredient novelty.

What is the PAZEO formulation and which excipients does it contain?

PAZEO is an ophthalmic solution for the temporary prevention of itching of the eye associated with allergic conjunctivitis. The approved strength is olopatadine hydrochloride ophthalmic solution 0.7%, administered as one drop in each affected eye once daily [1].

Component	PAZEO role	Commercial and technical relevance
Olopatadine hydrochloride 0.7%	Active pharmaceutical ingredient	Provides once-daily antihistamine and mast-cell-stabilizing activity
Benzalkonium chloride 0.01%	Preservative	Enables multidose packaging but creates ocular-surface tolerability concerns
Dibasic sodium phosphate	Buffering agent	Supports pH control and chemical stability
Sodium chloride	Tonicity agent	Helps approximate ocular comfort and isotonicity
Hydrochloric acid and sodium hydroxide	pH adjustment	Controls formulation pH
Purified water	Vehicle	Aqueous ophthalmic solvent

The formulation has a near-neutral pH and is designed as a sterile multidose aqueous solution. The preservative system is commercially efficient because it supports conventional dropper packaging, but it also creates a clear differentiation pathway for preservative-free competitors.

Why is benzalkonium chloride strategically important?

Benzalkonium chloride, or BAK, is widely used in ophthalmic products because it is effective at low concentrations and compatible with many multidose containers. Its limitations are cumulative ocular-surface exposure, potential epithelial toxicity, and concern among patients with chronic use, dry eye, contact-lens intolerance, or multiple topical therapies [2].

For seasonal allergy treatment, exposure may be intermittent. The risk-benefit profile is therefore different from chronic glaucoma therapy, where patients may use preserved drops for years. Even so, BAK-free positioning can support premium pricing and physician preference, particularly in patients with ocular-surface disease.

The commercial implication is that BAK is both a cost advantage and a product-differentiation vulnerability.

What excipient strategies can improve on PAZEO?

Four formulation strategies offer the clearest commercial paths.

Preservative-free unit-dose olopatadine

A preservative-free, single-use vial could remove the principal tolerability objection to PAZEO. The product would need validated sterility, low extractables and leachables, acceptable fill accuracy, and packaging that limits waste.

The disadvantages are higher packaging costs, greater logistics burden, and more product discarded after opening. Unit-dose packaging also reduces convenience for patients who need repeated seasonal treatment.

This strategy is most attractive for:

• Dry-eye and ocular-surface disease patients
• Pediatric users
• Contact-lens wearers, subject to labeling requirements
• Ophthalmology practices that prefer preservative-free therapy
• Premium private-label or specialty-pharmacy products

Preservative-free multidose delivery

A preservative-free multidose bottle could provide better convenience than unit-dose packaging. Suitable systems may use one-way valves, airless pumps, microbiological barriers, or mechanically protected droppers.

The device becomes part of the regulatory and intellectual-property strategy. A developer must demonstrate container-closure integrity, microbial ingress protection, dose uniformity over the in-use period, and compatibility between the formulation and dispensing materials.

This approach can command a stronger commercial position than a conventional generic because the differentiation resides in the delivery system rather than the active ingredient.

Alternative preservatives

Potential alternatives include oxidative systems, polyquaternium-based preservatives, and proprietary preservative technologies. Each option changes the product’s safety profile, manufacturing controls, packaging requirements, and regulatory burden.

An alternative preservative is less commercially compelling than a truly preservative-free product if the label still carries a preservative-related tolerability concern. It can, however, support a lower-cost multidose product where unit-dose packaging is impractical.

Reduced-drop-volume delivery

A conventional ophthalmic drop may exceed the volume the conjunctival sac can retain. A smaller, more controlled drop could reduce overflow, improve dose efficiency, and lower systemic absorption. A low-volume product may also reduce the total amount of preservative delivered per administration.

The key challenge is maintaining reliable delivered dose across bottle orientation, squeezing force, temperature, and remaining fill volume. A smaller drop alone is unlikely to justify premium pricing unless it is combined with preservative-free delivery or a patient-convenience claim.

What formulation patents protect PAZEO and olopatadine products?

The principal intellectual-property risk lies in patents covering concentrated olopatadine ophthalmic formulations, not only in the basic use of olopatadine for allergic conjunctivitis. Public patent records associated with olopatadine ophthalmic formulations include U.S. Patent No. 8,791,124 and related formulation claims assigned to Alcon entities [3].

IP category	Relevance to PAZEO competitors	Typical design-around path
Olopatadine ophthalmic composition	May cover concentration, pH, excipient combinations, or stability	Change buffer, preservative, concentration, or pH within acceptable limits
Method of treating allergic conjunctivitis	May cover dosing frequency or patient population	Use different approved indication or rely on distinct labeling strategy
Preservative-free formulations	May cover excipient exclusion and packaging	Use a different container system or formulation architecture
Multidose dispensing systems	May protect valve, pump, or sterile barrier technology	License device technology or develop an independent system
Manufacturing and sterilization processes	May limit specific processing methods	Use aseptic processing, terminal sterilization where feasible, or alternative controls

A formulation change does not automatically avoid infringement. Patent analysis must compare claim limitations against the complete formulation, manufacturing process, package, and labeled use.

When does PAZEO lose exclusivity?

PAZEO’s five-year new-chemical-entity exclusivity has expired. The relevant commercial barriers are therefore patent listings, regulatory requirements, brand recognition, and product economics rather than remaining NCE exclusivity.

The Orange Book should be used to confirm current listed patents, pediatric exclusivity, and any litigation status for the specific NDA and strength [4]. Patent expiry dates can differ by patent and can be affected by patent-term adjustment, terminal disclaimers, and court outcomes. Public records associated with PAZEO-related formulation patents have included expiry dates extending into the late 2020s or early 2030s, depending on the patent family and claim scope [3,4].

What is the FDA and Orange Book status of PAZEO?

PAZEO was approved by the FDA in February 2015 under NDA 207825 for allergic conjunctivitis [1,5]. It is a prescription ophthalmic product. The broader olopatadine market also includes Pataday products and generic olopatadine formulations at different strengths.

Regulatory item	Status
Active ingredient	Olopatadine hydrochloride
Strength	0.7% ophthalmic solution
Dosage form	Sterile topical ophthalmic solution
FDA route	NDA approval for PAZEO; ANDA pathway available for qualifying generics
Dosing	One drop in each affected eye once daily
Therapeutic category	Ophthalmic antihistamine and mast-cell stabilizer
Orange Book relevance	Listed patents and exclusivity must be assessed against NDA 207825
Biosimilar pathway	Not applicable; olopatadine is a small molecule

An ANDA applicant generally must demonstrate pharmaceutical equivalence and bioequivalence or otherwise satisfy FDA-specific requirements for the reference product. A generic does not necessarily need to copy every inactive ingredient, but differences may trigger additional safety, equivalence, labeling, or product-quality considerations.

Are there Paragraph IV challenges to PAZEO?

Paragraph IV risk depends on the patents currently listed for NDA 207825 and whether those patents remain enforceable and relevant to the proposed product. A generic applicant can certify that a listed patent is invalid, unenforceable, or will not be infringed. The brand holder may then initiate patent litigation within the statutory period, potentially creating a 30-month stay of ANDA approval under the Hatch-Waxman framework [6].

The commercial assessment should distinguish between:

1. Paragraph IV certification filed.
2. Patent litigation initiated.
3. FDA approval blocked by a statutory stay.
4. Settlement reached.
5. ANDA approval granted after patent expiry or litigation resolution.
6. Commercial launch, which may occur later than approval.

Publicly available litigation and Orange Book records should be reviewed for the current status of each listed PAZEO patent. A historical absence of litigation does not eliminate future risk if a new ANDA filing challenges a still-listed patent.

How strong is the PAZEO patent estate?

The estate is strongest where claims combine multiple limitations, such as:

• 0.7% olopatadine strength
• Specific pH range
• Defined buffer system
• Preservative concentration
• Chemical-stability profile
• Once-daily dosing
• Particular formulation or packaging configuration

The estate is weaker against products that use the same active ingredient but differ materially in excipient architecture, container system, concentration, or manufacturing process, provided those changes do not fall within the asserted claims.

A practical strength assessment should score each patent on four factors:

Factor	Assessment
Claim breadth	Narrow composition claims are easier to design around than broad treatment claims
Remaining term	Late-term patents provide less durable commercial protection
Validity exposure	Formulation patents may face prior-art and obviousness challenges
Product overlap	Risk increases when the proposed product reproduces the reference formulation

The strongest commercial defense may therefore be brand and channel control rather than patent exclusivity alone.

Which companies are competing with PAZEO?

Alcon is the principal commercial company associated with PAZEO and the Pataday franchise. Competitive products include:

• Pataday once-daily olopatadine products
• Generic olopatadine hydrochloride ophthalmic solutions
• Ketotifen ophthalmic products
• Azelastine ophthalmic products
• Prescription antihistamine and mast-cell stabilizer combinations
• Nonprescription allergy-eye products

Pataday creates an important internal substitution risk. If the same or similar olopatadine technology is sold through an OTC brand, PAZEO’s prescription positioning may lose differentiation.

How does PAZEO compare with ketotifen and other allergy drops?

Product type	Typical dosing advantage	Excipient opportunity	Commercial limitation
Olopatadine 0.7%	Once daily	Preservative-free and low-volume versions	Mature active ingredient
Olopatadine lower strengths	Once or twice daily depending on product	Lower-cost generic products	Less differentiated
Ketotifen	Often twice daily	Alternative preservative and OTC packaging	More frequent dosing
Azelastine	Prescription positioning	Device and tolerability improvements	Smaller commercial base in some markets
Mast-cell stabilizer products	Preventive use	Combination or preservative-free versions	Slower onset or more frequent dosing for some products

PAZEO’s once-daily regimen remains a useful commercial feature, but it is unlikely to support a high premium without improved tolerability or delivery convenience.

What commercial opportunities exist for PAZEO-style products?

Preservative-free premium product

The most defensible opportunity is a BAK-free olopatadine 0.7% product in unit-dose or protected multidose packaging. Pricing can be supported by ocular-surface tolerability, physician preference, and specialty distribution.

Generic and private-label supply

Manufacturers can pursue lower-cost olopatadine products for retail pharmacies, health systems, and international markets. The opportunity is strongest where the reference brand has limited distribution and local procurement favors generic substitution.

Emerging-market licensing

Licensing opportunities may include regional rights for:

• Olopatadine ophthalmic solution
• Preservative-free packaging
• Local manufacturing
• Private-label OTC allergy products
• Hospital and pharmacy-chain supply

A licensing deal is more attractive when it includes differentiated packaging or regulatory dossiers rather than only active-ingredient supply.

Combination products

Olopatadine may be evaluated in combination with lubricants or other ocular-surface excipients. Combination products increase development complexity because the developer must establish compatibility, preservative performance, stability, dosing rationale, and regulatory justification.

Device-led differentiation

A controlled-drop bottle, low-volume actuator, or preservative-free multidose system can create a product with stronger commercial separation than an excipient substitution alone. Device patents and freedom-to-operate analysis become central.

What manufacturing and IP barriers affect new PAZEO products?

The main manufacturing barriers are sterile processing, low bioburden control, preservative-effectiveness testing, extractables and leachables, container-closure integrity, and stability after opening.

BAK-containing products are comparatively simple to package in conventional multidose bottles. Preservative-free products require more expensive packaging and tighter microbiological controls. This raises unit cost and may reduce gross margin unless the product earns premium pricing.

The principal IP barriers are formulation patents, device patents, manufacturing claims, and trademark or trade-dress restrictions. A developer should also separate formulation freedom to operate from regulatory substitutability. A technically noninfringing product may still require additional FDA work if its inactive ingredients or delivery system differ materially from the reference product.

What generic launch scenarios exist for PAZEO?

Three launch scenarios are commercially realistic:

1. Conventional generic: Matches the reference strength and dosage form, uses a similar preservative system, and competes primarily on price.
2. Differentiated generic: Uses a distinct excipient system, improved comfort profile, or alternative container.
3. Branded specialty product: Uses preservative-free packaging, controlled-drop delivery, or a premium ocular-surface positioning.

The conventional generic has the lowest development cost but faces rapid price erosion. The differentiated generic requires greater regulatory and manufacturing investment but can avoid direct price competition. The specialty product has the highest margin potential and the greatest technical and market-access risk.

Key Takeaways

• PAZEO contains olopatadine hydrochloride 0.7%, BAK 0.01%, phosphate buffer, sodium chloride, pH adjusters, and purified water.
• BAK is the principal excipient-based vulnerability because it enables low-cost multidose packaging but limits ocular-surface differentiation.
• Preservative-free unit-dose and multidose products offer the clearest commercial opportunity.
• PAZEO has no remaining NCE exclusivity; current risk depends on listed patents, ANDA certifications, litigation, and product-specific FDA requirements.
• Olopatadine is a small molecule, so biosimilar risk does not apply.
• Generic competition is likely to pressure conventional PAZEO pricing.
• Device-led delivery, low-volume dosing, and specialty ocular-surface positioning can create stronger margins.
• Patent analysis must cover formulation, method of use, packaging, and manufacturing claims together.
• Pataday and other olopatadine products create internal and external substitution pressure.
• The strongest launch model is a preservative-free or delivery-differentiated product supported by a defensible device and regulatory strategy.

FAQs

Is PAZEO preservative-free?

No. PAZEO contains benzalkonium chloride 0.01% as a preservative [1].

Can a generic PAZEO use different inactive ingredients?

Yes, subject to FDA requirements for pharmaceutical equivalence, safety, quality, and bioequivalence. Different excipients or packaging may increase regulatory and technical requirements.

Is olopatadine subject to biosimilar competition?

No. Olopatadine is a small-molecule active ingredient. Competition proceeds through generic-drug and, in some markets, OTC pathways rather than biosimilar regulation.

What is the best excipient opportunity for a new olopatadine product?

A preservative-free formulation with a validated multidose delivery system offers the strongest combination of patient differentiation, convenience, and premium potential.

Does a BAK-free PAZEO alternative automatically avoid patent infringement?

No. A BAK-free product may avoid some formulation limitations but can still implicate patents covering olopatadine concentration, pH, treatment methods, packaging, manufacturing, or broader composition claims.

References

1. U.S. Food and Drug Administration. (2015). PAZEO (olopatadine hydrochloride ophthalmic solution) prescribing information.
2. Baudouin, C., Labbé, A., Liang, H., Pauly, A., & Brignole-Baudouin, F. (2010). Preservatives in eyedrops: The good, the bad and the ugly. Progress in Retinal and Eye Research, 29(4), 312-334.
3. U.S. Patent and Trademark Office. (2014). U.S. Patent No. 8,791,124, ophthalmic formulations of olopatadine.
4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
5. U.S. Food and Drug Administration. (2015). PAZEO NDA 207825 approval letter.
6. U.S. Food and Drug Administration. (2023). Hatch-Waxman amendments and abbreviated new drug applications.