Bulk Pharmaceutical API Sources for DARVON COMPOUND

Bulk Pharmaceutical API Sources for DARVON COMPOUND

Vendor	Vendor Homepage	Vendor Sku	API Url
ChemExper Chemical Directory		HknD@DATf^UuFVh@J`@@
Specs		AE-848/04969036
Sigma-Aldrich		235830_ALDRICH

Bulk Active Pharmaceutical Ingredient (API) Sources for: Darvon Compound

Last updated: August 4, 2025

Introduction

Darvon Compound, historically marketed as a pain relief medication, primarily integrated the active pharmaceutical ingredient (API) propoxyphene, often in combination with other analgesics. Responsible sourcing of API is critical for ensuring safety, efficacy, and regulatory compliance, particularly given propoxyphene’s controversial history and its withdrawn status in multiple markets. This review consolidates current insights into bulk API sources relevant to Darvon Compound, emphasizing supply chain integrity, regulatory landscape, and vendor qualification.

Background on Darvon Compound

Originally developed in the 1950s, Darvon compounds primarily contained propoxyphene napsylate (or hydrochloride), coupled with acetaminophen or aspirin. The API, propoxyphene, is a synthetic opioid analgesic. Due to concerns over safety—chiefly abdominal and cardiovascular risks—regulatory agencies like the U.S. Food and Drug Administration (FDA) withdrew propoxyphene from the market in 2010[1]. Despite its market withdrawal, formulations and APIs related to Darvon still persist in legacy inventories, compounding manufacturing or research contexts.

API Manufacturing and Sourcing Landscape

1. Main API Manufactures and Regions

a. Established API Manufacturers

• Mallinckrodt Pharmaceuticals: Historically supplied APIs for analgesics; retains capabilities but largely phased out propoxyphene due to regulatory issues.
• Jiangsu Hengrui Medicine Co., Ltd.: Based in China, one of the largest API producers, with the capability to manufacture propoxyphene raw materials in the past.
• Zhejiang NHU Co., Ltd.: A major Chinese API manufacturer, with a diverse portfolio including opioids; potential supplier of propoxyphene or similar APIs.
• Siegfried AG: Swiss manufacturer with expertise in custom API synthesis; limited publicly known production of propoxyphene but could provide custom synthesis options.

b. Regions of API Production

• Asia (China and India): Dominant in API manufacturing, offering competitive pricing and high-volume capacity.
• Europe and North America: Focused on high-quality APIs with stringent regulatory compliance, though with limited production of APIs like propoxyphene post-withdrawal.

2. Regulatory and Quality Considerations

Given the safety concerns and regulatory withdrawal, sourcing APIs like propoxyphene is highly restricted:

• Regulatory Restrictions: Following the FDA’s withdrawal, APIs for propoxyphene may be classified as controlled or restricted substances under local laws.
• Quality Standards: Only APIs produced under Good Manufacturing Practices (GMP) and with active regulatory approval remain viable, particularly for investigational or legacy use.

3. Sourcing Challenges and Ethical Considerations

• Supply Limitations: The discontinuation and regulatory restrictions have led to significant supply shortages.
• Verification of Authenticity: Due to black market proliferation and fraudulent APIs, rigorous vendor qualification is essential.
• Legal Risks: Sourcing propoxyphene APIs outside regulatory frameworks exposes legal and compliance risks.

Leading API Suppliers and Vendors

Supplier Name	Location	Capabilities	Notes
Jiangsu Hengrui Medicine	China	API synthesis, including opioids	Potential provider; verify regulatory compliance
Zhejiang NHU Co., Ltd.	China	API production, custom synthesis	Quality assurance critical
Siegfried AG	Switzerland	API development, custom synthesis	Limited known production of propoxyphene
Therapeutic Systems, Inc.	USA	API sourcing and contract manufacturing	Regulatory oversight necessary

Key Considerations for sourcing API for Darvon Compound

• Regulatory Compliance: Only procure APIs with documented GMP certification and regulatory approval in target markets.
• Supplier Qualification: Conduct thorough audits, verify batch documentation, and review audit reports.
• Traceability: Maintain traceability of the API batch from manufacturing to final use.
• Legal Status: Confirm current legal restrictions pertaining to propoxyphene in the intended jurisdiction.

Current Market Outlook and Future Trends

Due to the withdrawal of propoxyphene globally, legitimate procurement options are primarily for legacy or research purposes. A limited number of suppliers maintain inventory or custom synthesis capabilities — primarily for authorized research institutions. Alternative opioids or analgesics are increasingly replacing propoxyphene in formulation development.

Emerging legislative measures and increased regulatory oversight aim to prevent illicit use and ensure patient safety, further constraining legal sourcing channels. Companies seeking to reintroduce therapeutics involving propoxyphene would need to navigate complex regulatory hurdles or consider alternative APIs.

Conclusion

Sourcing bulk API for Darvon Compound—particularly propoxyphene—poses significant challenges. The declining global approval status restricts legitimate supply channels, accentuating the importance of verifying supplier compliance, regulatory adherence, and quality control. Moving forward, entities must prioritize transparent, compliant sourcing avenues, underscoring the importance of due diligence to mitigate legal and safety risks.

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Key Takeaways

• The withdrawal of propoxyphene from global markets limits legitimate supply sources for Darvon APIs.
• Asian manufacturers, especially Chinese firms, remain primary production hubs but require stringent qualification processes.
• Regulatory and legal constraints demand rigorous verification and compliance, especially with APIs classified as controlled substances.
• Alternative analgesics are increasingly replacing propoxyphene, influencing future API sourcing and formulation strategies.
• Companies must implement comprehensive due diligence, including GMP verification, traceability, and legal compliance, when sourcing APIs related to Darvon or its compounds.

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FAQs

Q1: Is it legal to purchase propoxyphene API today?
A: In most jurisdictions, procurement of propoxyphene API is heavily restricted or prohibited due to its withdrawal over safety concerns. Legal sourcing is typically limited to authorized research or manufacturing within strict regulatory frameworks.

Q2: Which regions are most active in manufacturing or supplying propoxyphene API?
A: China has historically been a major source of APIs, including opioids, but current restrictions have curtailed commercial production. Europe and North America have ceased production, focusing on regulatory compliance and safety.

Q3: How can companies ensure the quality of sourced API?
A: Conduct comprehensive vendor qualification, verify GMP certification, review batch documentation, and require Certificates of Analysis for each batch. Auditing manufacturing sites and ensuring regulatory approval are essential.

Q4: Are there alternative APIs suitable for pain management that are easier to source?
A: Yes. Non-opioid analgesics like NSAIDs (e.g., ibuprofen, naproxen) or newer opioids with safer profiles are more readily available and pose fewer regulatory challenges.

Q5: What are the risks associated with sourcing APIs from unverified suppliers?
A: Risks include substandard or falsified products, legal penalties, regulatory non-compliance, and potential safety hazards to patients or researchers.

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References

[1] U.S. Food and Drug Administration (FDA). “FDA Announces Labeling Changes and Safety Alerts for Propoxyphene.” 2010.