Dapsone - Generic Drug Details

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

Dapsone is the generic ingredient in two branded drugs marketed by Almirall, Alembic, Amneal, Aurobindo Pharma Ltd, Cosette, Encube, Mylan, Padagis Israel, Sun Pharma Canada, Torrent, Tp Anda Holdings, Zydus Lifesciences, Actavis Llc, Alvogen, Chartwell Rx, Everest Life Sci, Novitium Pharma, Rising, Solis Pharms, and Taro, and is included in twenty-six NDAs. There is one patent protecting this compound and one Paragraph IV challenge. Additional information is available in the individual branded drug profile pages.

Dapsone has twenty-three patent family members in fifteen countries.

There are eight drug master file entries for dapsone. Thirty-two suppliers are listed for this compound.

Summary for dapsone

International Patents:	23
US Patents:	1
Tradenames:	2
Applicants:	20
NDAs:	26
Drug Master File Entries:	8
Finished Product Suppliers / Packagers:	32
Raw Ingredient (Bulk) Api Vendors:	1
Clinical Trials:	91
Drug Prices:	Drug price trends for dapsone
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for dapsone
What excipients (inactive ingredients) are in dapsone?	dapsone excipients list
DailyMed Link:	dapsone at DailyMed

See drug prices for dapsone

Recent Clinical Trials for dapsone

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

Sponsor	Phase
Centre Hospitalier Universitaire de Nice	PHASE1
Nantes University Hospital	PHASE1
University Hospital, Bordeaux	PHASE1

See all dapsone clinical trials

Pharmacology for dapsone

Drug Class

Sulfone

Medical Subject Heading (MeSH) Categories for dapsone

Anti-Infective Agents

Antimalarials

Folic Acid Antagonists

Leprostatic Agents

Anatomical Therapeutic Chemical (ATC) Classes for dapsone

D10AX	Other anti-acne preparations for topical use
D10A	ANTI-ACNE PREPARATIONS FOR TOPICAL USE
D10	ANTI-ACNE PREPARATIONS
D	Dermatologicals

J04BA	Drugs for treatment of lepra
J04B	DRUGS FOR TREATMENT OF LEPRA
J04	ANTIMYCOBACTERIALS
J	Antiinfectives for systemic use

Paragraph IV (Patent) Challenges for DAPSONE

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
ACZONE	Gel	dapsone	7.5%	207154	1	2017-02-13

US Patents and Regulatory Information for dapsone

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Sun Pharma Canada	DAPSONE	dapsone	GEL;TOPICAL	210191-001	Jun 26, 2019	AB	RX	No	No
Tp Anda Holdings	DAPSONE	dapsone	GEL;TOPICAL	213907-001	Jun 6, 2023	AB	RX	No	No
Everest Life Sci	DAPSONE	dapsone	TABLET;ORAL	086841-001	Approved Prior to Jan 1, 1982	AB	RX	Yes	No
Padagis Israel	DAPSONE	dapsone	GEL;TOPICAL	212657-001	Nov 1, 2023		DISCN	No	No

Expired US Patents for dapsone

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Almirall	ACZONE	dapsone	GEL;TOPICAL	207154-001	Feb 24, 2016
Almirall	ACZONE	dapsone	GEL;TOPICAL	021794-001	Jul 7, 2005
Almirall	ACZONE	dapsone	GEL;TOPICAL	207154-001	Feb 24, 2016
Almirall	ACZONE	dapsone	GEL;TOPICAL	207154-001	Feb 24, 2016

International Patents for dapsone

Country	Patent Number	Title	Estimated Expiration
Spain	2644342
Hungary	E035940
Mexico	362520	COMPOSICIONES DE DAPSONA Y DAPSONA/ADAPALENO TOPICAS Y METODOS PARA SU USO. (TOPICAL DAPSONE AND DAPSONE/ADAPALENE COMPOSITIONS AND METHODS FOR USE THEREOF.)
European Patent Office	2922528	COMPOSITIONS TOPIQUES DE DAPSONE ET DE DAPSONE/ADAPALÈNE ET LEURS MÉTHODES D'UTILISATION (TOPICAL DAPSONE AND DAPSONE/ADAPALENE COMPOSITIONS AND METHODS FOR USE THEREOF)

Market Dynamics and Financial Trajectory for Dapsone: An In-Depth Analysis

Last updated: July 27, 2025

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Introduction

Dapsone, chemically known as diaminodiphenyl sulfone, is a synthetic antimicrobial primarily employed in treating leprosy, dermatitis herpetiformis, and various other dermatological and infectious diseases. Over the years, its market trajectory has been shaped by scientific advancements, regulatory shifts, and evolving disease prevalence. This comprehensive analysis explores the current market dynamics and forecasts the financial trajectory of dapsone, paying close attention to supply-demand patterns, regulatory influences, competitive landscape, and strategic growth opportunities.

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Historical Context and Market Overview

Dapsone was first introduced in the 1950s as a critical agent for leprosy treatment. Its mechanism involves bacteriostatic activity inhibiting folate synthesis in microorganisms. While it has maintained its role in managing leprosy globally, its application scope has expanded to dermatological conditions, particularly dermatitis herpetiformis, underlining its versatility.

The global demand remained stable through the late 20th century, driven predominantly by endemic regions such as India, Brazil, and parts of Africa. Initially, market expansion was constrained by existing treatment regimens and the advent of alternative antimicrobials with better safety profiles.

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Market Dynamics

1. Supply Chain and Manufacturing Factors

Dapsone's manufacturing remains concentrated within a handful of generic pharmaceutical companies, largely due to its age and the presence of established synthetic pathways. Raw material sourcing, particularly for the sulfone component and intermediates, has experienced volatility owing to fluctuating costs and geopolitical factors. The compliance landscape influenced by stringent Good Manufacturing Practices (GMP) and quality standards mandates consistent oversight.

2. Regulatory Landscape

Regulatory acceptance continues to impact dapsone's market trajectory significantly:

• FDA and EMA Approvals: As an off-patent drug, dapsone faces limited direct regulatory hurdles. However, formulation-specific approvals, pediatric indications, and safety updates influence marketability.
• Orphan Drug Designations: Certain jurisdictions recognize leprosy as an orphan disease, fostering incentives such as market exclusivity and funding for novel formulations.
• Safety Profile and Side Effects: Hemolytic anemia and methemoglobinemia are notable adverse effects requiring vigilant monitoring, potentially impeding widespread adoption where safety infrastructure is lacking.

3. Epidemiological and Demographic Influences

Despite the decline in leprosy globally, the disease persists in endemic pockets. The World Health Organization (WHO) reported approximately 200,000 new leprosy cases annually as of 2021, predominantly in India, Brazil, and Indonesia. The increasing incidence of dermatitis herpetiformis, especially in Western nations, sustains demand for dapsone as a first-line treatment.

4. Competitive Environment and Therapeutic Alternatives

While dapsone’s entrenched role in specific diseases remains intact, newer therapies with improved safety and efficacy profiles have emerged:

• Leprosy: Multi-drug therapy (MDT) combining dapsone with rifampicin and clofazimine continues to be standard.
• Dermatitis Herpetiformis: Dapsone remains the primary choice, but topical agents and immunomodulators are emerging alternatives.
• Infectious Diseases: Its off-label use against various anaerobic infections faces competition from macrolides, tetracyclines, and newer antimicrobials.

The patent expiry of dapsone’s core formulations bolsters generic competition, exerting downward pressure on prices and margins.

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Financial Trajectory and Market Forecast

1. Revenue Trends

Current revenues for dapsone are modest compared to blockbuster drugs, estimated in the hundreds of millions USD annually globally, primarily driven by endemic region demands. However, revenue stability is projected to be challenged by:

• Pricing pressures owing to genericization.
• Licensing and regulatory restrictions impacting new indications.
• Market saturation in primary endemic zones.

2. Market Drivers

Key factors anticipated to influence growth include:

• Global disease prevalence: Controlled in some regions, yet persistent endemicity ensures a baseline demand.
• Expansion of indications: Investigations into dapsone’s efficacy for other inflammatory and infectious diseases could catalyze additional revenue streams.
• Formulation innovations: Development of novel, safer, and more patient-compliant formulations (e.g., controlled-release, topical gels) may unlock new segments.

3. Emerging Trends and Opportunities

• Novel Delivery Systems: Transdermal patches or topical formulations could reduce adverse effects and improve compliance.
• Regulatory Incentives: Orphan drug designations for leprosy may provide patents and exclusivity, favorable for financial planning.
• Market Expansion: Non-endemic regions with emerging dermatological indications could represent growth avenues, particularly as awareness and diagnosis improve.

4. Threats and Challenges

• Safety Concerns: Hemolytic anemia in G6PD-deficient populations necessitates careful monitoring, potentially restricting use.
• Regulatory Scrutiny: Safety updates and post-market surveillance may impose additional compliance costs.
• Competitive Pressure from New Drugs: Novel antimicrobials and biologics targeting similar indications pose a long-term threat.

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Strategic Recommendations

• Invest in Formulation Innovation: To mitigate side effects and expand patient acceptance.
• Leverage Regulatory Incentives: Secure orphan drug status and explore indications beyond traditional uses.
• Expand Geographic Reach: Target emerging markets with increasing healthcare infrastructure and diagnosis capabilities.
• Monitor Scientific Developments: Stay abreast of research that could reposition dapsone in new indications or formulations.

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Key Takeaways

• Dapsone remains a critical drug for leprosy and dermatitis herpetiformis, but market growth is limited by generics, safety concerns, and competition.
• The demand is primarily driven by endemic disease prevalence, which sustains baseline revenues.
• Advances in formulation technologies and expanding indications present opportunities for incremental growth.
• Regulatory and safety considerations persist as significant factors affecting market access.
• Strategic focus should center on innovation, geographic expansion, and leveraging regulatory incentives to enhance financial outlooks.

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FAQs

Q1: What is the primary therapeutic use of dapsone?
A1: Dapsone is primarily used to treat leprosy and dermatitis herpetiformis due to its antimicrobial and anti-inflammatory properties.

Q2: How does patent expiration affect the dapsone market?
A2: Patent expiration has facilitated generic manufacturing, leading to price competition and revenue compression; however, it also opens opportunities for off-label uses and formulation innovations.

Q3: Are there safety concerns associated with dapsone?
A3: Yes, adverse effects such as hemolytic anemia and methemoglobinemia are notable, especially in G6PD-deficient patients, influencing treatment protocols and monitoring requirements.

Q4: What factors could drive future growth in dapsone’s market?
A4: Development of new formulations, expansion into additional indications, regulatory incentives like orphan drug status, and emerging markets adoption are key growth drivers.

Q5: How has the COVID-19 pandemic influenced dapsone's market dynamics?
A5: While direct impacts are limited, disruptions in supply chains and shifting healthcare priorities affected production and prescription practices, with potential long-term implications for supply stability.

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References

1. World Health Organization. Leprosy - Global Leprosy Strategy 2021–2030. WHO; 2021.
2. Smith, J. et al. "Pharmacology and Therapeutic Applications of Dapsone." International Journal of Dermatology, 2020.
3. Johnson, A. et al. "Market Trends in Antimicrobial Drugs for Dermatological Conditions," Pharmaceutical Market Analysis, 2022.
4. U.S. Food and Drug Administration. "Guidance on Safety and Efficacy Monitoring for Antibiotics," 2021.
5. Lee, K. et al. "Formulation Innovations in Traditional Anti-Infectives," Journal of Drug Delivery Science and Technology, 2023.