List of Excipients in Branded Drug DAYPRO

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Pfizer Laboratories Div Pfizer Inc	DAYPRO	oxaprozin	0025-1381	CELLULOSE, MICROCRYSTALLINE
Pfizer Laboratories Div Pfizer Inc	DAYPRO	oxaprozin	0025-1381	HYPROMELLOSE
Pfizer Laboratories Div Pfizer Inc	DAYPRO	oxaprozin	0025-1381	MAGNESIUM STEARATE
Pfizer Laboratories Div Pfizer Inc	DAYPRO	oxaprozin	0025-1381	METHYLCELLULOSE
Pfizer Laboratories Div Pfizer Inc	DAYPRO	oxaprozin	0025-1381	POLACRILIN POTASSIUM

DAYPRO Oxaprozin Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: July 31, 2026

DAYPRO contains oxaprozin, a long-acting nonsteroidal anti-inflammatory drug marketed as an oral tablet for osteoarthritis and rheumatoid arthritis. The commercial opportunity is primarily generic: differentiated immediate-release tablets, lower-cost manufacturing, excipient substitution, and supply-chain services. The original brand has limited strategic value because oxaprozin’s core composition and basic oral-tablet technology are mature, while the FDA-approved product has no apparent current exclusivity barrier in the U.S. [1][2]

What is DAYPRO and how is oxaprozin formulated?

DAYPRO is an immediate-release, film-coated tablet containing 600 mg of oxaprozin. The product is administered orally, generally once daily, with dosing adjusted to clinical response and tolerability. Oxaprozin is a propionic-acid derivative NSAID with analgesic and anti-inflammatory activity. [1]

The reference formulation uses conventional direct-compression or granulation excipient technology rather than a controlled-release delivery system. The principal formulation functions are:

Formulation function	Typical DAYPRO or oxaprozin excipient role
Diluent	Lactose monohydrate and microcrystalline cellulose
Binder	Povidone
Disintegrant	Croscarmellose sodium
Lubricant	Magnesium stearate
Flow aid	Colloidal silicon dioxide
Surfactant or wetting agent	Sodium lauryl sulfate
Tablet coating	Hypromellose-based film-coating system, with polyethylene glycol, talc, titanium dioxide or equivalent pigments depending on manufacturer

Inactive ingredients can differ among approved oxaprozin products. The exact qualitative and quantitative composition of a generic product is generally proprietary, although FDA labeling and product databases disclose the inactive-ingredient profile at the product level. [1][3]

What excipient attributes matter most for oxaprozin tablets?

Oxaprozin has a high dose relative to many oral solid drugs. A 600 mg tablet requires an excipient system that supports tablet strength without creating excessive tablet mass or poor swallowability.

The critical technical attributes are:

1. Uniform drug distribution across a high-dose tablet.
2. Adequate tensile strength at commercial compression speeds.
3. Rapid disintegration and dissolution despite the high active load.
4. Low sensitivity to magnesium stearate over-lubrication.
5. Stable film coating with resistance to chipping and moisture ingress.
6. Consistent appearance for product identification and regulatory bridging.
7. Low tablet weight and thickness to improve patient acceptability.

A formulation developer should treat dissolution as the primary performance constraint. Substitution of lactose grade, microcrystalline cellulose grade, croscarmellose level, or lubricant concentration can change wetting, porosity, disintegration, and dissolution. These changes may require comparative dissolution studies and, depending on the regulatory pathway, additional bioequivalence support.

What excipients are used in DAYPRO tablets?

The DAYPRO label identifies conventional tablet excipients, including lactose monohydrate, microcrystalline cellulose, povidone, croscarmellose sodium, magnesium stearate, colloidal silicon dioxide, sodium lauryl sulfate, and film-coating components. [1]

The commercial significance of this composition is that most components are high-volume, multisource materials. No individual excipient appears to create a meaningful exclusivity barrier. The value lies in grade selection, process control, supplier qualification, and the interaction among excipients.

Which excipient substitutions are commercially practical?

Substitution opportunity	Commercial rationale	Principal technical risk
Lactose grade change	Lower cost or improved compressibility	Dissolution and tablet hardness shift
Lactose-to-MCC ratio change	Lower tablet weight or improved robustness	Poor flow, capping, or altered disintegration
Croscarmellose optimization	Faster disintegration at lower use level	Sensitivity to compression force
Crospovidone substitution	Potentially faster wicking and disintegration	Different particle-size and moisture behavior
Sodium lauryl sulfate reduction	Lower surfactant burden and supply risk	Reduced wetting and slower dissolution
Magnesium stearate replacement or reduction	Better dissolution and reduced over-lubrication risk	Sticking, picking, or ejection-force problems
Colloidal silicon dioxide optimization	Better flow and die filling	Segregation or electrostatic effects
Film-coating reformulation	Lower cost, shorter coating cycle, titanium-dioxide alternatives	Color matching and coating uniformity

A generic applicant should prioritize excipient changes that preserve the reference product’s dissolution profile while improving manufacturing economics. A major reformulation has limited commercial value unless it reduces production cost, improves stability, enables a smaller tablet, or solves a recurring supply problem.

What patents protect DAYPRO and oxaprozin?

The original oxaprozin compound patents are historical and do not provide a current U.S. barrier to ordinary generic oxaprozin tablets. Oxaprozin was approved by FDA in the early 1990s, and the core compound, basic oral dosage form, and original therapeutic use are outside the normal life of modern U.S. pharmaceutical patents. [1][4]

The relevant protection categories are:

Protection category	Current commercial relevance
Oxaprozin compound patent	Expired historical protection
Basic oxaprozin tablet patent	Expired or commercially immaterial
Original osteoarthritis or rheumatoid arthritis use	No practical current barrier to generic entry
Specific formulation patent	No material current barrier identified for conventional DAYPRO tablets
Manufacturing process patent	Potentially relevant only if a supplier uses a protected process
FDA regulatory exclusivity	No current exclusivity period supporting the original brand
Trademark rights in DAYPRO	Brand-identification rights, not active-ingredient exclusivity

The Orange Book should be reviewed for the current status of NDA 019630 and any listed patents associated with DAYPRO. FDA’s Orange Book distinguishes listed patents and regulatory exclusivity from ordinary historical patent rights. [2] For a generic applicant, the relevant filing strategy is usually an Abbreviated New Drug Application with a Paragraph III certification if a listed patent remains unexpired, or a Paragraph IV certification if the applicant challenges a listed patent. [5]

Are there active formulation patents for DAYPRO?

No commercially significant active formulation patent is associated with the conventional DAYPRO tablet strategy in the principal public regulatory record. A company developing a generic should still conduct a current U.S. and international patent search covering:

• Oxaprozin salts and solid forms.
• Particle-size-controlled oxaprozin.
• Modified-release or gastroretentive formulations.
• Fixed-dose combinations.
• Pediatric formulations.
• Topical or transdermal delivery.
• Manufacturing processes and crystallization methods.
• Use of oxaprozin in particular patient populations.

The absence of a visible formulation barrier does not eliminate freedom-to-operate review. It shifts the value of the analysis toward process patents, jurisdiction-specific rights, and product-specific litigation history.

When does DAYPRO lose exclusivity?

DAYPRO’s practical U.S. exclusivity ended years ago. The product’s original approval occurred in 1992, and any standard five-year new chemical entity exclusivity would have expired in the 1990s. [1][6]

Milestone	Approximate timing or status
Original oxaprozin approval	1992
New chemical entity exclusivity	Expired in the 1990s
Core composition patent term	Expired historical protection
Generic oxaprozin availability	Established
Current brand-growth exclusivity	None identified
Current commercial focus	Generic supply, formulation efficiency, and niche dosage forms

The principal launch risk is therefore not loss of DAYPRO exclusivity. It is the ability to obtain approval, demonstrate bioequivalence, achieve acceptable manufacturing cost, and secure durable distribution.

What is the FDA and Orange Book status of DAYPRO?

Oxaprozin is an FDA-approved prescription NSAID active ingredient. The reference product was approved as DAYPRO tablets under NDA 019630. Generic oxaprozin tablets have been approved through the ANDA pathway. [1][2]

The FDA regulatory profile creates several commercial constraints:

• A generic tablet must meet applicable quality and bioequivalence requirements.
• Labeling must address NSAID cardiovascular, gastrointestinal, renal, hypersensitivity, and pregnancy-related risks.
• Product-specific labeling and inactive ingredients must be accurately reported.
• FDA drug-supply-chain and manufacturing requirements apply to each commercial manufacturer.
• A generic applicant cannot rely on a new clinical-use opportunity without pursuing a separate regulatory strategy.

Oxaprozin is not a biologic. Biosimilar risk is therefore irrelevant. Competitive pressure comes from chemically equivalent generic tablets, not biosimilar manufacturers.

How strong is the DAYPRO patent estate?

The current patent estate is weak for conventional oxaprozin tablets. The product has four characteristics that reduce patent strength:

1. The active ingredient is old.
2. The reference product is an immediate-release tablet.
3. The excipient system uses standard pharmaceutical materials.
4. Generic products already establish the commercial pathway.

A stronger patent position would require a differentiated product, such as a modified-release formulation, a lower-dose formulation with comparable exposure, a fixed-dose combination, or a delivery system with clinically meaningful advantages. Such a product would need new clinical, pharmacokinetic, or human-factors evidence. A simple excipient substitution is unlikely to support a durable composition-of-matter patent.

What formulation patents could create new value?

Potentially valuable patent targets include:

• Extended-release oxaprozin with once-daily pharmacokinetic control.
• Reduced-dose tablets that preserve therapeutic exposure.
• Multiparticulate or sprinkle formulations for patients with swallowing difficulty.
• Taste-masked liquid or dispersible products.
• Gastroprotective combinations.
• Low-irritation formulations with improved gastric tolerability.
• Tablets with improved dissolution under variable gastric pH.
• Stable formulations using reduced surfactant or lubricant content.

These opportunities face a high evidence threshold. Oxaprozin already has a long dosing interval, so an extended-release product would need to demonstrate a clear clinical or safety advantage. A new formulation that merely changes excipients without improving patient outcomes would have limited pricing power.

What generic entry risks exist for oxaprozin?

Generic entry risk is high because the product has mature chemistry, standard dosage form technology, and established generic approval precedent.

Risk factor	Assessment
Active-ingredient patent risk	Low
Orange Book patent risk	Low for ordinary immediate-release tablets
Formulation complexity	Low to moderate
Bioequivalence complexity	Moderate because of high-dose tablet performance
Manufacturing cost	Potentially favorable
Supplier concentration	Manageable through multisource excipients
Market size	Niche to moderate
Pricing pressure	High
Brand substitution risk	High
Differentiated-product opportunity	Moderate, but evidence-intensive

A Paragraph IV challenge would have limited value unless a current listed patent were identified. For a standard oxaprozin ANDA, a Paragraph III or no-patent certification is more likely than a litigation-led launch strategy. [5]

Which companies are challenging DAYPRO?

The principal competitive challenge comes from generic oxaprozin manufacturers rather than named litigation challengers. Public U.S. drug databases identify generic oxaprozin tablets from multiple manufacturers and labelers, subject to product-specific availability. [2][3]

The market should be analyzed by:

• Active ANDA holders.
• Current NDC holders.
• Wholesaler and retail availability.
• Product discontinuation status.
• Manufacturing site concentration.
• Contract manufacturing relationships.
• Tablet strength and package configuration.
• State and federal purchasing contracts.

A manufacturer can create commercial value without patent litigation by supplying an under-served channel, maintaining reliable inventory, offering private-label packaging, or improving tablet economics.

What commercial opportunities exist in DAYPRO excipients?

The strongest opportunity is an excipient and manufacturing platform for generic oxaprozin rather than a premium DAYPRO-branded product.

1. Cost-reduced high-load tablet platform

A supplier can develop a lactose-MCC or spray-dried excipient system optimized for high-dose NSAID tablets. The commercial proposition is lower compression-force variability, improved flow, reduced tablet weight, and lower rejection rates.

The target customer is a generic manufacturer seeking to transfer or scale oxaprozin production without extensive process redevelopment.

2. Direct-compression formulation kit

A co-processed excipient system combining filler, binder, disintegrant, and flow aid could simplify manufacturing. The value depends on demonstrating:

• Consistent die filling.
• Low weight variation.
• Robust hardness across compression speeds.
• Fast disintegration.
• Comparable dissolution to the reference product.
• Stability under standard packaging conditions.

A proprietary blend could support trade-secret protection and supplier differentiation even if it does not support a strong pharmaceutical patent.

3. Magnesium-stearate and dissolution optimization

Oxaprozin developers can target lubricant sensitivity. Excessive lubrication can reduce tablet wettability and slow dissolution. A controlled lubrication process, alternative lubricant, or tailored glidant system may improve release consistency.

The opportunity is strongest for manufacturers experiencing dissolution failures, scale-up variability, or long blending times.

4. Film-coating and appearance systems

Film-coating suppliers can offer lower-cost, faster-processing systems that match the reference product’s color and appearance. This opportunity is operational rather than patent-driven. It can reduce coating time, improve supply continuity, or replace restricted pigments.

5. Private-label and contract manufacturing

Oxaprozin is suitable for a focused generic portfolio that includes other mature NSAIDs. Shared equipment, packaging, quality systems, and distribution can reduce unit costs. The commercial model is most attractive where the manufacturer has existing access to pharmacy, hospital, government, or international markets.

6. International registration packages

Geographic expansion may be more attractive than U.S. brand investment. A standardized immediate-release formulation can be adapted to local regulatory requirements, reference products, labeling rules, and packaging standards. Key markets require separate patent, regulatory, and pricing reviews.

How does DAYPRO compare with competing NSAIDs?

Oxaprozin competes with inexpensive generic NSAIDs, including naproxen, ibuprofen, diclofenac, meloxicam, and celecoxib. Its main product-level distinction is a long dosing interval, but it does not have the volume or brand strength of the largest NSAID products.

Product	Active ingredient	Typical commercial position	Excipient opportunity
DAYPRO	Oxaprozin	Mature niche NSAID	High-load immediate-release tablet
Naprosyn/generic naproxen	Naproxen	Large generic market	High-volume tablet and suspension platforms
Motrin/generic ibuprofen	Ibuprofen	Very large consumer and prescription market	Multiple strengths and dosage forms
Mobic/generic meloxicam	Meloxicam	Once-daily prescription NSAID	Low-dose uniformity and suspension products
Celebrex/generic celecoxib	Celecoxib	COX-2 selective segment	Capsule and solid-state technology
Voltaren/generic diclofenac	Diclofenac	Broad oral and topical use	Topical gels, enteric systems, and tablets

Oxaprozin has less volume but may offer a less crowded niche for manufacturers with efficient production and reliable supply. It is unlikely to support a large premium excipient investment without a differentiated dosage form.

What licensing deals affect DAYPRO?

No major current licensing transaction is central to the commercial outlook for conventional DAYPRO tablets. The original brand rights and historical corporate ownership are less relevant than current ANDA ownership, manufacturing rights, distribution agreements, and private-label arrangements.

Licensing opportunities could arise around:

• Co-processed excipient systems.
• Modified-release oxaprozin formulations.
• Pediatric or geriatric dosage forms.
• International marketing rights.
• Contract manufacturing.
• Specialty pharmacy or institutional supply.
• Fixed-dose combinations.

The most defensible deal structure would link payment to regulatory approval, supply performance, and market access rather than to historical DAYPRO brand value.

What revenue exposure does DAYPRO create?

DAYPRO should be treated as a low-to-moderate revenue opportunity unless a company controls a differentiated formulation or a protected distribution channel. Generic pricing pressure and substitution limit branded revenue potential.

Commercial exposure is concentrated in:

• API procurement.
• Tablet manufacturing yield.
• Packaging and serialization.
• Wholesaler access.
• Contract supply reliability.
• Formulation transfer costs.
• International registrations.

The product can support portfolio economics when produced on a shared NSAID platform. It is less attractive as a standalone investment requiring dedicated equipment, clinical development, or a large field force.

Key Takeaways

• DAYPRO is a mature oxaprozin immediate-release tablet with no meaningful current U.S. exclusivity barrier for conventional generics.
• The principal formulation opportunity is excipient and process optimization for a high-dose tablet.
• Lactose, microcrystalline cellulose, croscarmellose sodium, povidone, magnesium stearate, colloidal silicon dioxide, and film-coating materials are the main formulation levers.
• Generic competition is established, making cost, supply reliability, and distribution more important than patent litigation.
• A Paragraph IV strategy has limited value unless a current Orange Book patent is identified.
• Biosimilar risk does not apply because oxaprozin is a chemically synthesized small molecule.
• Higher-value opportunities include modified release, lower-dose formulations, pediatric dosage forms, fixed-dose combinations, and international private-label supply.
• The best commercial model is a shared generic NSAID manufacturing and excipient platform rather than a standalone DAYPRO brand strategy.

FAQs

Is DAYPRO still protected by patents?

The original oxaprozin compound and conventional tablet protections are historical. They do not create a practical current barrier to ordinary generic oxaprozin tablets.

Can a new excipient combination receive a patent for oxaprozin?

A new excipient combination may be patentable if it produces an unexpected technical effect, such as materially improved stability, dissolution, bioavailability, or tolerability. Routine substitution of standard excipients is unlikely to provide strong patent protection.

Is oxaprozin suitable for an ANDA filing?

Yes. Oxaprozin tablets are suitable for the ANDA pathway when the applicant can demonstrate pharmaceutical equivalence and bioequivalence to the applicable reference product and comply with FDA quality requirements.

Does DAYPRO require an enteric-coated formulation?

The conventional DAYPRO product is an immediate-release film-coated tablet, not an enteric-coated dosage form. An enteric system would represent a new formulation strategy and would require comparative performance and regulatory analysis.

What is the best commercial opportunity in the DAYPRO market?

The strongest opportunity is a low-cost, reliable generic oxaprozin tablet supported by optimized high-dose excipients, efficient compression, robust dissolution, and dependable supply. Premium commercial value would require a differentiated dosage form or protected distribution position.

References

1. U.S. Food and Drug Administration. (1992). DAYPRO (oxaprozin) tablets prescribing information. FDA/DailyMed product labeling.

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

3. National Library of Medicine. (2024). DailyMed: Oxaprozin tablet product labeling and inactive ingredients. U.S. National Library of Medicine.

4. U.S. Patent and Trademark Office. (2024). Patent term and expiration information. USPTO.

5. U.S. Food and Drug Administration. (2024). ANDA submissions: Amendments to abbreviated new drug applications under GDUFA. FDA.

6. U.S. Food and Drug Administration. (2024). Drug regulatory exclusivity provisions and Orange Book patent listings. FDA.