FDA Office of Generic Drugs Advances Bioequivalence Standards and Complex ANDA Pathways Under GDUFA III

Manufacturers pursuing complex generic approvals face a shifting regulatory science baseline, and the FDA Office of Generic Drugs (OGD) 2023 Annual Report signals that GDUFA III-funded research is actively redefining how bioequivalence and product quality are assessed for those submissions.

Under GDUFA III, authorized in October 2022, the FDA expanded scientific meeting availability for sponsors working on harder-to-develop complex generics and continued advancing research into characterization methods that directly inform ANDA review standards. OGD Director Iilun Murphy, M.D., noted that GDUFA-funded work in 2023 contributed to novel, more efficient development pathways, a signal that product quality frameworks and bioequivalence methodologies for complex dosage forms are not static targets.

The operational weight of that research is visible in the approval record. In 2023, the FDA approved or tentatively approved 956 ANDAs, including 90 first generics. Among them was the first generic naltrexone extended-release injectable suspension, referencing Vivitrol, a biodegradable polymer-microsphere product whose manufacture and regulatory assessment OGD explicitly characterized as substantially more complex than conventional oral solid dosage forms. For quality and manufacturing teams working in sterile injectables or long-acting formulations, that approval establishes a precedent for how OGD will evaluate comparability of microsphere-based systems.

For ANDA strategy leads, the report reinforces that OGD's annual public input process directly shapes regulatory science priorities, and by extension, the product-specific guidance and bioequivalence recommendations that govern submission requirements. Teams preparing complex ANDA packages should monitor OGD research publications as leading indicators of evolving assessment criteria, particularly for products where no established bioequivalence methodology currently exists.

International collaboration remains a parallel workstream. OGD continued engagement with foreign regulatory authorities in 2023 to align scientifically driven guidelines, a trajectory relevant to manufacturers operating under multiple jurisdictional submissions and seeking convergence across bioequivalence standards.

The 956 ANDA approvals recorded against GDUFA III's first full operational year will serve as the baseline against which OGD measures throughput and review quality commitments in subsequent performance reporting.

Source: FDA Office of Generic Drugs via FDA Voices (fda.gov), June 1, 2026.