Highly Potent APIs

Safe handling of highly potent APIs in isolator by two operators in protection suits

High Potent API Manufacturing

As a seasoned contract manufacturer of highly potent active pharmaceutical ingredients (HPAPIs) with over three decades of experience, we are at the forefront of the industry and possess the expertise required to handle the distinct challenges that come with these powerful compounds. We serve as your capable and reliable CDMO partner, providing you with a range of scale and handling capabilities down to single-digit nanogram containment.

  • Our facilities are certified by SafeBridge®, an industry leader in HPAPI handling certification, ensuring the utmost safety and security in all our operations.
  • We offer an extensive portfolio of payload and advanced payload intermediate products that can accelerate your drug development.

Our commitment to quality and regulatory standards extends from pre-clinical to commercial programs, and our global supply chain network ensures the highest quality of raw materials sourcing. We seamlessly integrate with downstream ADC/bioconjugation service offers, providing you with end-to-end solutions for your pharmaceutical needs.

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As one of the first facilities to receive SafeBridge® certification, we have been industry leaders in safe handling of Highly Potent APIs (HPAPIs) for over 30 years. To continue to build upon that pioneering spirit, we have invested heavily in our new Verona, Wisconsin HPAPI facility which boasts 6 new kilo labs with single-digit nanogram occupational exposure limit (OEL) containment. This innovative facility design raises the global standard for the safe handling of the industry’s most potent APIs.


Drug Development Acceleration Products

Accelerate your drug development efforts with our comprehensive product line of payloads and advanced payload intermediates. These products add value to your program by reducing development costs, decreasing supply chain complexity, and increasing speed of synthesis through reduction of required reaction steps – together accelerating your speed to clinic. 

Chemical structure of MAYCore™ (CAS 77668-69-0)
Advanced Maytansine Intermediate

MAYCore™ is an advanced intermediate that simplifies maytansine payload synthesis. Proprietary maytansinoid synthesis can be modified to meet your specific linker-payload needs.

  • 3 g samples available free of charge
  • HPLC Purity >95%
Maytansinoid Products for Your Drug Conjugate Program



The global footprint of our HPAPI contract manufacturing services assures you wide-ranging regulatory and supply expertise, easily accessed through a single trusted partner.

Madison, Wisconsin, United States: GMP contract manufacturing services for HPAPIs, APIs, advanced intermediates and linker-payloads
Madison & Verona, United States

Our API and HPAPI manufacturing sites are SafeBridge certified. Continued investment and expansion in these facilities build upon our decades of high potency expertise and makes us one of the largest single-digit nanogram OEL CTDMO providers in the world.

St. Louis, Missouri, United States: GMP contract manufacturing services for ADC and Bioconjugation, and Small Molecule bio-organics
St. Louis, Missouri, United States

GMP contract manufacturing services for ADC and Bioconjugation, and Small Molecule bio-organics.

ISO 9001 certified development to commercial scale production site  in Sheboygan Falls
Sheboygan Falls, United States

ISO 9001:2008 certified site meeting customer needs from development to commercial‑scale production of registered starting material.

Related Technical Resources

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