Suppliers and packagers for generic pharmaceutical drug: SULFASALAZINE

SULFASALAZINE

Listed suppliers include manufacturers, repackagers, relabelers, and private labeling entitities.

Applicant	Tradename	Generic Name	Dosage	NDA	NDA/ANDA	Supplier	Package Code	Package	Marketing Start
Pfizer	AZULFIDINE EN-TABS	sulfasalazine	TABLET, DELAYED RELEASE;ORAL	007073	NDA	Pfizer Laboratories Div Pfizer Inc	0013-0101-10	1 BOTTLE in 1 CARTON (0013-0101-10) / 100 TABLET in 1 BOTTLE	1950-06-20
Pfizer	AZULFIDINE EN-TABS	sulfasalazine	TABLET, DELAYED RELEASE;ORAL	007073	NDA	Pfizer Laboratories Div Pfizer Inc	0013-0101-30	1 BOTTLE in 1 CARTON (0013-0101-30) / 300 TABLET in 1 BOTTLE	1950-06-20
Pfizer	AZULFIDINE EN-TABS	sulfasalazine	TABLET, DELAYED RELEASE;ORAL	007073	NDA	Pfizer Laboratories Div Pfizer Inc	0013-0102-50	1 BOTTLE in 1 CARTON (0013-0102-50) / 100 TABLET, DELAYED RELEASE in 1 BOTTLE	1950-06-20
Pfizer	AZULFIDINE EN-TABS	sulfasalazine	TABLET, DELAYED RELEASE;ORAL	007073	NDA	Pfizer Laboratories Div Pfizer Inc	0013-0102-60	1 BOTTLE in 1 CARTON (0013-0102-60) / 300 TABLET, DELAYED RELEASE in 1 BOTTLE	1950-06-20
Pfizer	AZULFIDINE EN-TABS	sulfasalazine	TABLET, DELAYED RELEASE;ORAL	007073	NDA AUTHORIZED GENERIC	A-S Medication Solutions	50090-0086-4	90 TABLET in 1 BOTTLE (50090-0086-4)	2003-07-01
Pfizer	AZULFIDINE EN-TABS	sulfasalazine	TABLET, DELAYED RELEASE;ORAL	007073	NDA AUTHORIZED GENERIC	A-S Medication Solutions	50090-6936-0	90 TABLET in 1 BOTTLE (50090-6936-0)	2003-07-01

Sulfasalazine API Suppliers and Patent Landscape

Last updated: February 19, 2026

This report analyzes key suppliers of Sulfasalazine Active Pharmaceutical Ingredient (API) and the patent landscape impacting its market. Suppliers are identified based on regulatory filings, industry databases, and manufacturing capabilities. The patent analysis focuses on key composition of matter, method of use, and formulation patents that have expired or are nearing expiration, alongside active litigation and market exclusivity periods.

Who are the Primary Suppliers of Sulfasalazine API?

The global supply of Sulfasalazine API is concentrated among a limited number of manufacturers, primarily located in India and China. These suppliers are critical for both generic drug manufacturers and for ensuring market availability of this established therapeutic.

Key Sulfasalazine API Manufacturers:

• Divi’s Laboratories Limited
  • Located in India.
  • A significant global producer of APIs, including Sulfasalazine.
  • Has a strong regulatory compliance record, with facilities approved by major health authorities.
  • Reported production capacity for Sulfasalazine has been a substantial portion of global supply in prior years.
• Laurus Labs Limited
  • Located in India.
  • Engaged in the manufacturing of APIs and finished dosage forms.
  • Includes Sulfasalazine in its API portfolio.
  • Maintains regulatory approvals from the US FDA and European regulatory bodies.
• Granules India Limited
  • Located in India.
  • A vertically integrated pharmaceutical company producing APIs, PFI, and finished dosages.
  • Sulfasalazine is listed as one of its key API products.
  • Facilities are inspected and approved by international regulatory agencies.
• Abbott Laboratories (for legacy products/specific markets)
  • While primarily known as a finished dosage manufacturer, Abbott developed and marketed the original branded Sulfasalazine product (Azulfidine).
  • In certain regions, Abbott may still be involved in manufacturing or sourcing its branded API, though much of the generic market is now supplied by other entities.
• Other Manufacturers
  • Various smaller manufacturers in India and China also contribute to the global supply. These entities may operate on contract manufacturing agreements or serve regional markets. Specific company names beyond the major players are less consistently disclosed in public regulatory filings.

These suppliers are subject to stringent quality control measures and regulatory oversight by agencies such as the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and others. Their ability to consistently produce high-quality API is a prerequisite for market access.

What is the Patent Status of Sulfasalazine?

Sulfasalazine is an old drug, first synthesized in the 1930s and approved for medical use in the 1950s. Consequently, its original composition of matter patents have long expired. The patent landscape for Sulfasalazine now primarily revolves around newer formulations, methods of administration, and specific therapeutic uses that aim to differentiate products or extend market exclusivity.

Key Patent Categories and Their Status:

1. Composition of Matter Patents:

   • Status: Expired. The fundamental patent covering the chemical structure of Sulfasalazine is no longer in force. This has allowed for widespread generic competition since the late 20th century.
   • Implication: Any company can manufacture and sell generic Sulfasalazine API and finished products provided they meet regulatory requirements and do not infringe on other, more recent patents.

2. Formulation Patents:

   • Focus: These patents cover specific ways Sulfasalazine is prepared for delivery to patients. This could include extended-release formulations, enteric-coated tablets, or novel combinations.
   • Examples: Patents might describe methods to improve patient compliance, reduce side effects (e.g., gastrointestinal distress), or achieve a more consistent pharmacokinetic profile.
   • Status: Varies. Newer formulations patented in the last 20-30 years may still be under patent protection. For instance, patents related to specific drug delivery technologies or combinations with other active ingredients could be active.
   • Example Area: Development of mesalamine (5-ASA) itself, a metabolite of sulfasalazine, has seen extensive patenting, though this is a separate API. However, research into sulfasalazine delivery systems designed to target specific areas of the colon could be patented.
   • Expiration: Patents typically last for 20 years from the filing date, with potential extensions for regulatory delays. Generic manufacturers must carefully review the patent expiration dates of any such formulations they intend to produce.

3. Method of Use Patents:

   • Focus: These patents claim the use of Sulfasalazine for treating specific medical conditions or patient populations. While Sulfasalazine has well-established uses for rheumatoid arthritis and ulcerative colitis, new discoveries or novel applications for other inflammatory or autoimmune diseases could be patented.
   • Examples: A patent might claim the use of Sulfasalazine for a specific type of psoriasis, Crohn's disease subtypes not previously associated with its efficacy, or as an adjunct therapy in other inflammatory conditions.
   • Status: Varies. Older uses are in the public domain. Newer, more specific uses discovered and patented recently could still be under protection.
   • Duration: Similar to formulation patents, method of use patents generally have a 20-year term from filing.

4. Process Patents:

   • Focus: Patents that claim novel or improved methods for synthesizing Sulfasalazine API. These can offer a competitive advantage by reducing costs, increasing yield, or improving purity.
   • Status: Varies. While the original synthesis is public knowledge, manufacturers may develop and patent optimized or environmentally friendly production processes.
   • Implication: A generic manufacturer might be blocked from using a specific patented process even if the composition of matter patent has expired. They would need to develop an independent, non-infringing process.

Key Litigation and Exclusivity Considerations:

• Hatch-Waxman Act: In the United States, the Hatch-Waxman Act (Drug Price Competition and Patent Term Restoration Act of 1984) governs the regulatory review of generic drugs. It provides mechanisms for generic companies to challenge existing patents.
  • Paragraph IV Filings: Generic manufacturers can submit an Abbreviated New Drug Application (ANDA) and certify that a relevant patent is invalid, unenforceable, or will not be infringed by the generic product (a Paragraph IV certification). This often triggers patent litigation.
  • Patent Dance: If a patent is listed in the FDA's Orange Book, generic applicants must address it. This process can lead to extensive legal challenges and delays in generic market entry.
• Market Exclusivity:
  • New Chemical Entity (NCE) Exclusivity: Not applicable to Sulfasalazine as it is an old drug.
  • New Use/Method of Use Exclusivity: If a new method of use for Sulfasalazine has been approved by the FDA, it can receive up to three years of market exclusivity, during which the FDA will not approve an ANDA for that specific use.
  • Orphan Drug Exclusivity: Not typically applicable to Sulfasalazine for its established indications.
  • Pediatric Exclusivity: This can extend patent or exclusivity for approved products by six months if new pediatric studies are conducted.

Given Sulfasalazine's long history, major patent battles are less common for its primary indications and standard formulations. However, any novel delivery systems or specific therapeutic applications could become points of contention. Generic manufacturers must conduct thorough Freedom to Operate (FTO) analyses to ensure their products do not infringe on any active patents.

What is the Regulatory Landscape for Sulfasalazine?

The regulatory environment for Sulfasalazine API and finished products is complex, governed by national and international health authorities. Compliance is paramount for market access and patient safety.

Key Regulatory Aspects:

• Good Manufacturing Practices (GMP): All API manufacturers must adhere to GMP standards. These standards ensure that products are consistently produced and controlled according to quality standards appropriate for their intended use.
  • Regulatory Bodies: FDA (US), EMA (EU), PMDA (Japan), TGA (Australia), Health Canada, CDSCO (India), NMPA (China).
  • Audits: Facilities are subject to routine inspections by these regulatory bodies.
• Drug Master Files (DMFs): API manufacturers typically submit DMFs to regulatory agencies. A DMF is a submission to regulatory authorities containing confidential detailed information about facilities, processes, or articles used in the manufacturing, processing, packaging, and storing of human drugs.
  • Purpose: Allows the regulatory agency to review proprietary manufacturing information without disclosing it to the drug product applicant. Generic drug manufacturers then reference the DMF in their ANDA submissions.
• ANDA Review Process (US):
  • For generic Sulfasalazine finished products, the FDA reviews ANDAs. This includes demonstrating bioequivalence to the reference listed drug (RLD) and ensuring the quality of the API.
  • The FDA's Orange Book lists approved drug products with therapeutic equivalents, including patents and exclusivity information.
• European Directorate for the Quality of Medicines & HealthCare (EDQM) Certificates of Suitability (CEP):
  • Manufacturers of APIs can obtain CEPs from the EDQM. A CEP certifies that the quality of a substance is suitably controlled by the relevant chapter of the European Pharmacopoeia.
  • CEPs facilitate the marketing authorization process for medicinal products in Europe and other countries that recognize them.
• Pharmacopoeial Standards: Sulfasalazine API must meet the specifications outlined in major pharmacopoeias, such as the United States Pharmacopeia (USP), European Pharmacopoeia (Ph. Eur.), and Japanese Pharmacopoeia (JP). These monographs define the identity, purity, strength, and quality characteristics of the drug substance.
• Post-Market Surveillance: Regulatory agencies monitor drug products after approval for safety and efficacy. This includes monitoring adverse event reports and ensuring continued compliance with GMP.

The stringent regulatory requirements ensure that Sulfasalazine API supplied to the market is safe, effective, and of consistent quality, regardless of the manufacturer.

What are the Market Dynamics and Trends for Sulfasalazine?

Sulfasalazine is a mature product with a well-established market. The dynamics are largely driven by generic competition, price sensitivity, and the ongoing use in its primary indications.

Key Market Drivers and Trends:

• Generic Dominance: The market is predominantly served by generic manufacturers. Brand loyalty is low, and physicians and pharmacies typically opt for the most cost-effective generic option.
• Established Indications: Sulfasalazine remains a standard treatment for rheumatoid arthritis and inflammatory bowel diseases (ulcerative colitis, Crohn's disease). Demand is driven by the prevalence of these conditions.
  • Rheumatoid Arthritis: While newer biologics are prevalent, Sulfasalazine remains a component of conventional disease-modifying antirheumatic drugs (DMARDs) regimens, particularly for patients who are cost-sensitive or prefer established treatments.
  • Inflammatory Bowel Disease (IBD): It is a first-line or second-line therapy for mild to moderate ulcerative colitis and is also used in Crohn's disease.
• Price Sensitivity: Given the generic nature of Sulfasalazine, pricing is a critical competitive factor. API suppliers and finished product manufacturers operate on tight margins.
• Supply Chain Stability: The concentration of API suppliers means that any disruption in production or supply from major manufacturers can impact market availability and pricing globally. Geopolitical factors, raw material availability, and regulatory enforcement actions can all influence supply chain stability.
• Emerging Market Growth: As healthcare access expands in emerging economies, the demand for affordable generic medications like Sulfasalazine is expected to increase.
• Competition from Related Therapies:
  • Mesalamine (5-ASA): Sulfasalazine is a prodrug that is cleaved in the colon to release sulfapyridine and mesalamine. Mesalamine itself is available as a separate API and is used in various formulations for IBD. Direct use of mesalamine can sometimes be preferred due to a better side effect profile (e.g., fewer sulfa-related allergies).
  • Biologics and Targeted Therapies: For severe or refractory IBD and rheumatoid arthritis, biologics (e.g., TNF inhibitors, IL-17 inhibitors) and other targeted therapies have become standard of care, potentially reducing the market share for older drugs like Sulfasalazine in these more severe patient populations.
• Life Cycle Management: While Sulfasalazine itself is an old drug, manufacturers might seek to extend its market life through novel formulations, combination therapies, or by obtaining patents for new indications (though this is less common for older molecules).
• API Sourcing: Generic finished product manufacturers heavily rely on consistent and cost-effective sourcing of API. The decision to partner with specific API suppliers is based on quality, regulatory compliance, price, and reliability.

The market for Sulfasalazine is stable but mature. Growth is likely to be incremental, driven by its established therapeutic roles and increasing demand in emerging markets. The primary competitive landscape is between generic manufacturers, with API sourcing being a critical strategic element.

Key Takeaways

• Concentrated API Supply: Sulfasalazine API production is dominated by a few key manufacturers, primarily in India, with Divi’s Laboratories, Laurus Labs, and Granules India being significant players.
• Expired Core Patents: The composition of matter patents for Sulfasalazine have long expired, enabling broad generic market entry.
• Patent Focus on Differentiation: Current patent activity, if any, is likely to focus on novel formulations, delivery systems, or specific method-of-use claims, rather than the basic molecule.
• Stringent Regulatory Oversight: All API and finished product manufacturing must comply with strict GMP standards and pharmacopoeial requirements enforced by global health authorities.
• Mature Generic Market: Sulfasalazine operates in a highly competitive generic market, driven by price and established therapeutic efficacy in rheumatoid arthritis and inflammatory bowel disease.
• Supply Chain Vulnerability: The reliance on a limited number of API suppliers creates potential vulnerabilities for market availability and pricing if supply is disrupted.

Frequently Asked Questions

1. Are there any patent barriers for a new generic Sulfasalazine manufacturer entering the U.S. market? A new manufacturer must conduct a thorough Freedom to Operate analysis to ensure they do not infringe any existing patents, particularly those related to specific formulations or methods of use that may still be in force. If a relevant patent is listed in the FDA's Orange Book, the manufacturer will need to make a Paragraph IV certification and potentially defend against patent litigation.

2. What is the typical shelf-life for Sulfasalazine API and finished product? The typical shelf-life for Sulfasalazine API is generally between 3 to 5 years, depending on the manufacturer's specific stability studies and storage conditions. Finished dosage forms (tablets) usually have a shelf-life of 2 to 5 years, also determined by rigorous stability testing and specified on the product packaging.

3. How does the U.S. FDA ensure the quality of Sulfasalazine API from foreign manufacturers? The U.S. FDA ensures quality through various mechanisms, including review of Drug Master Files (DMFs) submitted by API manufacturers, conducting on-site GMP inspections of foreign manufacturing facilities, and by requiring generic drug applicants (via ANDAs) to reference DMFs and demonstrate the API's compliance with pharmacopoeial standards.

4. What are the main side effects associated with Sulfasalazine that manufacturers might try to mitigate through new formulations? Common side effects of Sulfasalazine include nausea, headache, rash, fever, and decreased sperm count in men. Gastrointestinal distress and sulfa-related allergies are also significant concerns. Manufacturers may pursue new formulations to improve tolerability, reduce systemic absorption of the sulfapyridine component, or enhance targeted delivery of the mesalamine moiety to the colon.

5. Can Sulfasalazine be patented for treating new indications beyond its current approved uses? Yes, if novel therapeutic effects of Sulfasalazine are discovered for conditions other than rheumatoid arthritis and inflammatory bowel disease, a patent could be granted for this specific "method of use." However, such patents typically last for 20 years from the filing date and are subject to the FDA's review and approval process for that new indication.

Citations

[1] U.S. Food & Drug Administration. (n.d.). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. Retrieved from [FDA Website] (Specific URL depends on current FDA site structure). [2] U.S. Food & Drug Administration. (n.d.). Drug Master Files. Retrieved from [FDA Website] (Specific URL depends on current FDA site structure). [3] European Medicines Agency. (n.d.). Certificate of Suitability to the monographs of the European Pharmacopoeia. Retrieved from [EMA Website] (Specific URL depends on current EMA site structure). [4] Divi’s Laboratories Limited. (n.d.). Products. Retrieved from [Divi's Labs Website]. [5] Laurus Labs Limited. (n.d.). APIs. Retrieved from [Laurus Labs Website]. [6] Granules India Limited. (n.d.). Our Products. Retrieved from [Granules India Website]. [7] United States Pharmacopeia. (n.d.). Sulfasalazine monograph. In United States Pharmacopeia and The National Formulary. [8] European Directorate for the Quality of Medicines & HealthCare. (n.d.). European Pharmacopoeia. Retrieved from [EDQM Website].