Bulk Pharmaceutical API Sources for rofecoxib

Bulk Pharmaceutical API Sources for rofecoxib

Vendor	Vendor Homepage	Vendor Sku	API Url
NIH Clinical Collection		SAM001246617
NovoSeek		5090
ISpharm		I01-1042

Bulk Active Pharmaceutical Ingredient (API) Sources for Rofecoxib

Last updated: August 8, 2025

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Introduction

Rofecoxib, marketed as Vioxx, was a non-steroidal anti-inflammatory drug (NSAID) developed by Merck & Co. for pain relief and inflammation control. Approved by the FDA in 1999, it garnered significant market share before its withdrawal in 2004 due to cardiovascular safety concerns. Despite its withdrawal, the API supply landscape remains relevant for generic manufacturing, research, and historical analysis. This report explores the current landscape of bulk API sources for rofecoxib, covering established suppliers, manufacturing complexities, and the implications for stakeholders.

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Overview of Rofecoxib API

Rofecoxib is a selective COX-2 inhibitor, characterized by its complex chemical structure involving a pyrazole core with specific substitutions. Its synthesis involves multiple steps, including aromatic substitution and cyclization, requiring high-purity reagents and strict manufacturing controls. The intricacies of its synthesis and quality standards profoundly impact API sourcing choices.

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Historical and Current API Manufacturers

Major Pharmaceutical API Producers

While Merck originally developed and scaled production of rofecoxib, the withdrawal and subsequent market contraction have limited active manufacturing. Several pharmaceutical companies and API manufacturers historically provided bulk rofecoxib:

• Merck & Co.: Original patent holder and primary producer pre-2004. No longer markets or produces the API post-withdrawal.

• Zhejiang Hisun Pharmaceutical Co., Ltd. (China): Reported as a supplier of generic APIs, including COX-2 inhibitors. Their involvement in rofecoxib's manufacturing has been speculative but plausible due to their extensive NSAID portfolio.

• Hetero Drugs (India): Known for generic APIs including NSAIDs like celecoxib and etoricoxib. There is some indication of Rofecoxib API manufacturing, although explicit public confirmation is limited.

• Aurobindo Pharma (India): Engaged in the production of COX-2 inhibitors and other NSAIDs, with potential capacity for rofecoxib API.

• Aventis (now part of Sanofi, France): Once involved in generic NSAID production, but no current evidence of rofecoxib API manufacturing.

Regional API Providers

In markets where generic manufacturing persisted post-withdrawal, API sourcing increasingly shifted toward India and China, owing to low-cost manufacturing:

• India: Several small-to-mid scale API producers have claimed the ability to produce rofecoxib, often targeting research or export markets.

• China: Leading API manufacturing hub, with companies like Zhejiang Hisun potentially providing rofecoxib API, either legally or through off-label manufacturing.

Note: Due to the drug's market withdrawal and safety issues, official registration and consistent supply of rofecoxib API have diminished significantly. Suppliers often operate in grey markets or technically export APIs for research purposes.

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Sources and Supply Chain Dynamics

Regulatory and Market Impact

The removal of rofecoxib from the market severely impacted global API supply chains. Regulatory restrictions in many jurisdictions limited the distribution and manufacturing of rofecoxib APIs, especially for human consumption.

The primary factors influencing API sourcing include:

• Regulatory status: With the drug withdrawn in numerous markets, APIs are often produced under strictly controlled conditions for research, analytical standards, or export.

• Patent and exclusivity rights: Post-withdrawal, patent protections expired, allowing generic manufacturers to produce similar APIs, but sourcing remains limited due to safety concerns.

• Manufacturing complexity: The intricate synthesis demands advanced facilities compliant with Good Manufacturing Practices (GMP). Smaller producers often lack the regulatory approval for pharmaceutical-grade APIs.

Legitimate vs. Illicit Sources

Although some companies advertise API production, many operate in a legal grey zone, especially with APIs like rofecoxib that hold safety concerns. Buyers must verify supplier credibility through certifications, GMP compliance, and regulatory approvals.

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Quality Assurance and Regulatory Compliance

High-quality API sourcing requires rigorous QC and compliance with Good Manufacturing Practices:

• Certificates of Analysis (CoA): Validation of purity (>99%), residual solvents, and other impurities.

• GMP Certification: Essential for pharmaceutical-grade API manufacturing.

• Inspection and audits: Buyers must conduct thorough due diligence to ensure suppliers’ adherence to regulatory standards.

Given the potential for counterfeit or substandard APIs in unregulated markets, stakeholders should prioritize vendors with verifiable credentials and robust supply chain transparency.

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Pricing and Commercial Considerations

The API market for rofecoxib is niche due to its market history; thus, pricing is often high and influenced by batch size, purity levels, and supply stability. The limited number of qualified suppliers further constrains pricing flexibility. Companies seeking to procure rofecoxib API should prepare for a rigorous vetting process and potentially higher costs amid supply uncertainties.

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Future Outlook

Despite its market withdrawal, interest persists in research settings, especially in pharmacological studies and comparative analyses. API supply may continue in small quantities via:

• Research bulk providers: Companies specializing in serendipitous or research-grade API synthesis.

• Gray markets: Unregulated supply channels, which pose significant quality and legal risks.

Long-term, the re-emergence of rofecoxib or similar compounds hinges on regulatory evaluations, safety analyses, and patent landscapes, shaping procurement and manufacturing strategies.

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Conclusion

The supply landscape for bulk rofecoxib API is characterized by limited, specialized sources amid regulatory and safety concerns. Major pharmaceutical companies have largely exited the market, with some Asian API manufacturers potentially serving niche markets for research or export purposes. Companies seeking genuine, compliant API sources must prioritize regulatory adherence, quality assurance, and supply chain integrity, recognizing the unique challenges posed by this drug’s market history.

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Key Takeaways

• Post-withdrawal, manufacturing and supply of rofecoxib API have drastically declined, with most sources operating in regulatory gray zones.
• Asian API manufacturers, particularly from India and China, possibly produce and export rofecoxib APIs primarily for research, with limited pharmaceutical-grade supply.
• Due diligence, including verifying GMP compliance and supplier certifications, is essential for procurement.
• Market dynamics and safety concerns continue to influence the availability, pricing, and legal considerations surrounding rofecoxib API.
• The future of rofecoxib API supply largely depends on ongoing regulatory assessments and research needs; market re-entry appears unlikely without substantial safety reevaluation.

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FAQs

1. Are there authorized suppliers of pharmaceutical-grade rofecoxib API today?
Limited to no; due to market withdrawal and safety concerns, authentic, GMP-certified suppliers are scarce. Purchasers often rely on research-scale or gray-market sources.

2. Can I legally buy rofecoxib API for commercial pharmaceutical manufacturing?
Probably not in most jurisdictions, as regulatory agencies restrict or prohibit the import and use of withdrawn APIs for human use.

3. What are the primary risks associated with sourcing rofecoxib API from unverified suppliers?
Risks include substandard purity, contamination, counterfeit products, legal liabilities, and safety concerns related to quality and safety.

4. Why did Merck cease the production of rofecoxib API?
Market withdrawal due to cardiovascular safety issues and declining commercial viability following regulatory actions.

5. Is there potential for reintroduction of rofecoxib into the market?
Currently unlikely, as safety concerns persist, and regulatory agencies continue to restrict its use. Any future reintroduction would require comprehensive safety reevaluation.

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Sources:

[1] U.S. Food and Drug Administration. “Vioxx (Rofecoxib) Withdrawal Information,” FDA, 2004.
[2] Merck & Co. Annual Reports and Patent Filings — Rofecoxib.
[3] Pharmaceutical Industry Reports, Global API Market Analysis, 2022.
[4] Indian and Chinese API Suppliers’ Public Disclosures, 2021-2023.
[5] Regulatory Guidelines on API Manufacturing and Importation, EMA and FDA.