The increasing demand for targeted therapies in oncology and rare diseases has driven the rapid expansion of high-potency active pharmaceutical ingredient (HPAPI) manufacturing. These compounds, characterized by occupational exposure limits (OELs) below 10 μg/m³ and often in the nanogram range, require specialized engineering controls, toxicological assessment, and occupational safety programs. This review examines current HPAPI manufacturing strategies, focusing on containment technologies, health-based exposure limits, and regulatory requirements. The derivation of health-based limits such as Permitted Daily Exposure (PDE) and Occupational Exposure Limits (OELs) forms the foundation of risk assessment, supported by Occupational Exposure Banding (OEB) for early-stage compounds. Facility architecture relies on the "Onion Model" of containment, integrating negative-pressure HVAC systems with 100% single-pass air, HEPA filtration, and Bag-In/Bag-Out (BIBO) housings. Primary containment includes rigid barrier isolators, split butterfly valves (SBVs), and rapid transfer ports (RTPs) for OEB 4 and 5 substances. Critical unit operations—micronization, weighing, dispensing—are performed within fully enclosed systems to prevent airborne release. Cleaning validation has shifted from traditional limits to health-based exposure limits (HBELs), utilizing Maximum Allowable Carryover (MACO) calculations based on PDE values. Occupational safety programs incorporate powered air-purifying respirators (PAPRs), double-gloving, medical surveillance, and real-time industrial hygiene monitoring. Emerging digital tools, including computational fluid dynamics (CFD) and digital twins, enable predictive containment design and continuous monitoring. Successful HPAPI manufacturing integrates robust toxicology, advanced engineering controls, and comprehensive occupational health programs to protect workers and ensure product quality.
Vishal Shah* (Fri,) studied this question.