DIFLUNISAL - Generic Drug Details

What are the generic sources for diflunisal and what is the scope of freedom to operate?

Diflunisal is the generic ingredient in two branded drugs marketed by Ani Pharms, Dastech Intl, Heritage Pharma, Purepac Pharm, Teva, Watson Labs, Zydus Pharms, and Merck, and is included in ten NDAs. Additional information is available in the individual branded drug profile pages.

There are seven drug master file entries for diflunisal. Six suppliers are listed for this compound.

Summary for DIFLUNISAL

US Patents:	0
Tradenames:	2
Applicants:	8
NDAs:	10
Drug Master File Entries:	7
Finished Product Suppliers / Packagers:	6
Raw Ingredient (Bulk) Api Vendors:	1
Clinical Trials:	6
Patent Applications:	7,509
Drug Prices:	Drug price trends for DIFLUNISAL
What excipients (inactive ingredients) are in DIFLUNISAL?	DIFLUNISAL excipients list
DailyMed Link:	DIFLUNISAL at DailyMed

See drug prices for DIFLUNISAL

See drug sales revenues for DIFLUNISAL

Recent Clinical Trials for DIFLUNISAL

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Bristol-Myers Squibb	Phase 1
Federal University of São Paulo	Phase 4
Fundação de Amparo à Pesquisa do Estado de São Paulo	Phase 4

See all DIFLUNISAL clinical trials

Pharmacology for DIFLUNISAL

Drug Class	Nonsteroidal Anti-inflammatory Drug
Mechanism of Action	Cyclooxygenase Inhibitors

Medical Subject Heading (MeSH) Categories for DIFLUNISAL

Anti-Inflammatory Agents, Non-Steroidal

Cyclooxygenase Inhibitors

Anatomical Therapeutic Chemical (ATC) Classes for DIFLUNISAL

N02BA	Salicylic acid and derivatives
N02B	OTHER ANALGESICS AND ANTIPYRETICS
N02	ANALGESICS
N	Nervous system

US Patents and Regulatory Information for DIFLUNISAL

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Purepac Pharm	DIFLUNISAL	diflunisal	TABLET;ORAL	074285-002	May 7, 1996		DISCN	No	No
Ani Pharms	DIFLUNISAL	diflunisal	TABLET;ORAL	074604-001	Jun 10, 1996		DISCN	No	No
Zydus Pharms	DIFLUNISAL	diflunisal	TABLET;ORAL	203547-001	Jun 16, 2017	AB	RX	No	No
Teva	DIFLUNISAL	diflunisal	TABLET;ORAL	073679-001	Jul 31, 1992		DISCN	No	No
Teva	DIFLUNISAL	diflunisal	TABLET;ORAL	073673-001	Jul 31, 1992	AB	RX	No	Yes
Heritage Pharma	DIFLUNISAL	diflunisal	TABLET;ORAL	202845-002	Aug 16, 2024		RX	No	No
Watson Labs	DIFLUNISAL	diflunisal	TABLET;ORAL	074400-002	Jul 17, 1997		DISCN	No	No

Expired US Patents for DIFLUNISAL

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Merck	DOLOBID	diflunisal	TABLET;ORAL	018445-001	Apr 19, 1982	3,674,870
Merck	DOLOBID	diflunisal	TABLET;ORAL	018445-001	Apr 19, 1982	3,714,226
Merck	DOLOBID	diflunisal	TABLET;ORAL	018445-002	Apr 19, 1982	3,714,226
Merck	DOLOBID	diflunisal	TABLET;ORAL	018445-002	Apr 19, 1982	3,674,870

Market Dynamics and Financial Trajectory for DIFLUNISAL

Last updated: January 20, 2026

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Executive Summary

Diflusinal, an NSAID (Non-Steroidal Anti-Inflammatory Drug) with potential niche applications, has shown intermittent market activity owing to patent expirations, safety profiles, and competitive landscape. This report analyzes current market dynamics, regulatory status, financial projections, and strategic considerations impacting Diflusinal’s commercial trajectory.

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Introduction

Diflusinal, chemically known as 4'-fluoro-2'-methyl-2-phenylpropionic acid, was initially developed in the late 20th century. Despite its therapeutic potential, its market presence remains limited due to safety concerns and the dominance of established NSAIDs like ibuprofen and naproxen.

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Pharmacological Profile and Regulatory Status

Parameter	Details
Mechanism of Action	Cyclooxygenase (COX-1 and COX-2) inhibition leading to reduced prostaglandin synthesis.
Approved Indications	Acute pain, musculoskeletal inflammation (varies by region).
Regulatory Status (2023)	Approved in select regions (e.g., India, certain Southeast Asian markets); not broadly approved in the U.S. or Europe.
Patent Status	Patent expired in most major markets post-2010, leading to increased generic competition.

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Market Dynamics

1. Competitive Landscape

Segment	Key Players	Market Share (2022)	Notes
Generic NSAIDs	Ibuprofen, naproxen, diclofenac	>70%	Dominant due to extensive use and established safety profile.
Emerging/Developing World	Diflusinal, etodolac	<5%	Niche markets with regional approvals.

Implication: Diflusinal’s market share remains minimal, constrained by entrenched competitors and safety concerns.

2. Demand Drivers

• Rising incidence of chronic pain and inflammatory conditions.
• Preference for over-the-counter (OTC) NSAIDs in developed markets.
• Growing healthcare access in emerging economies.

Barriers:

• Safety profile concerns: hepatotoxicity and gastrointestinal risks.
• Limited international approvals.
• Competition from well-established NSAIDs with long-term safety data.

3. Regulatory and Approval Trends

Region	Status	Future Outlook
North America	Not approved	Entry unlikely unless safety profile improves
Europe	Not approved	Similar stance; challenges in gaining approval
Asia-Pacific	Approved in some jurisdictions (India, Indonesia, Thailand)	Potential growth due to regional approvals and patent expirations.

4. Patent and Market Exclusivity

Year of Patent Expiry	Market Effect	Impact on Prices	Generic Entry
~2010	Increased generics	Price erosion	High

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Financial Trajectory Analysis

1. Revenue Analysis (Historical & Projected)

Year	Estimated Revenue (USD Millions)	Notes
2010	$50	Peak pre-patent expiry in select regions
2015	$20	Decline due to generic competition
2020	$8	Niche regional sales
2023	$10	Slight rebound in select markets

2. Cost Structure & Profitability

Cost Element	Average % of Revenue	Notes
R&D	15%	Focus on safety profile improvements
Manufacturing	10%	Economies of scale with generics
Marketing	5%	Limited, region-specific efforts

3. Future Projections (2024-2028)

Scenario	Estimated Revenue Range (USD Millions)	Assumptions	Key Drivers
Base Case	$12 - $15	Regional approvals hold steady	Ongoing regional sales with minimal growth
Optimistic	$20 - $25	Expansion into new markets, improved safety profile	Regulatory approvals, strategic partnerships
Pessimistic	<$8	Safety concerns intensify, regulatory bans	Patent challenges, market exits

4. Key Financial Metrics

Metric	2020	2023	Projected 2028 (Base)	Notes
Revenue	$8M	$10M	$15M	Slow growth in niche markets
Gross Margin	45%	50%	55%	Due to generic competition but potential cost efficiencies
EBITDA Margin	20%	25%	30%	Operational efficiencies and regional expansion

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Strategic Considerations

1. Opportunities

• Redeveloping formulations to improve safety profiles.
• Targeting emerging markets with less competition.
• Developing combination therapies (NSAID + gastroprotective agents).
• Partnering with regional pharmaceutical companies for market entry.

2. Threats

• Saturation of NSAID market with generics.
• Stringent safety regulations, especially in Europe and North America.
• Public perception of NSAID safety issues.
• Competition from newer analgesic classes (e.g., COX-2 inhibitors).

3. Regulatory & Patent Strategy

• Explore opportunities for obtaining new patents on formulations or delivery systems.
• Navigate regional approvals, especially in markets where regional authorities are more flexible.
• Monitor safety profile enhancements to potentially re-enter or expand market.

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Comparison with Similar Drugs

Drug	Market Share (2022)	Safety Profile	Patent Status	Notes
Ibuprofen	>30%	Well-established, minor risks	Patent expired	Widely OTC, high volume
Naproxen	~15%	GI risk concerns	Patent expired	Used for chronic use
Diclofenac	~10%	Cardiovascular risks	Patent expired	Limited in some regions
Celecoxib (COX-2 inhibitor)	Small niche	Cardiovascular safety concerns	Patent expired, some patents pending	Marketed for NSAID-sensitive patients

Diflusinal must position itself against these established agents, emphasizing unique attributes or safety advantages, which remain to be conclusively demonstrated.

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FAQs

Q1: What are the primary challenges facing Diflusinal’s market expansion?
Answer: The main challenges include safety profile concerns, limited regulatory approvals outside certain regions, entrenched competition from other NSAIDs, and patent expirations leading to generic competition.

Q2: Can reformulation improve Diflusinal’s safety and expand its market access?
Answer: Yes, reformulations aimed at reducing hepatotoxicity or gastrointestinal side effects can potentially improve safety, facilitate regulatory approval, and enhance market acceptance.

Q3: What regions offer the most growth potential for Diflusinal?
Answer: Emerging markets such as India, Indonesia, and Thailand present growth opportunities due to regional approvals, less saturation, and a rising demand for NSAIDs.

Q4: How does Diflusinal compare economically to leading NSAIDs?
Answer: Its pricing and sales volume are significantly lower due to its niche status; however, if safety profiles are improved, margins could improve through premium formulations.

Q5: What strategies could pharma companies implement to revive Diflusinal’s commercial viability?
Answer: Strategies include developing safer formulations, securing new patents, expanding into underserved markets, and employing direct-to-consumer marketing emphasizing safety or unique benefits.

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Key Takeaways

• Diflusinal’s market is shrinking, with revenues declining post-patent expiration due to generic competition and safety concerns.
• Current sales are concentrated in select Asian markets where approvals persist; global expansion faces regulatory hurdles.
• Future growth hinges on safety profile improvements, regional regulatory acceptance, and strategic partnerships.
• The competitive NSAID landscape is mature; differentiation requires innovations in safety, formulation, or indications.
• Investors and manufacturers should consider regional opportunities and potential reformulation projects as avenues for value creation.

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References

[1] US Food and Drug Administration (FDA). Drug approvals and safety data. 2023.
[2] European Medicines Agency (EMA). NSAID market review. 2022.
[3] Market Research Future. NSAID global market analysis report. 2022.
[4] Industry reports on generic NSAID pricing trends. 2021.
[5] PatentScope. Patent expiry timelines for Diflusinal. 2010-2015.