Generally, complex generics are products that have complex active ingredients, formulations, dosage forms, or routes of administration, or are complex drug-device combination products. Generics of complex brand name drugs (i.e., reference listed drugs) can be more difficult to develop. As such, a complex drug may be less likely to have an available generic.
To help patients access important medical treatments, FDA’s Center for Drug Evaluation and Research works to better understand the scientific issues impacting complex generic development and assessment. FDA shares these scientific insights publicly, further enabling generic drug applicants to develop complex products and helping to ensure that applicants have the necessary information to prepare complete submissions.
This page features news, information, and additional resources about FDA’s activities that support the development and approval of complex generic drugs.
Every year, FDA approves or tentatively approves hundreds of generic drug applications, including dozens of complex generics. Below is a list of recent notable complex generic approvals.
- On July 6, 2023, FDA approved the first generic Vivitrol (naltrexone for extended-release injectable suspension), 380 mg/vial, single-dose vial
Below is a list of recent and upcoming events regarding complex generics.
- September 13-14, 2023: SBIA Workshop: Advancing Generic Drug Development: Translating Science to Approval 2023
- October 12, 2023: FDA/CRCG Workshop: Advances in PBPK Modeling and its Regulatory Utility for Oral Drug Product Development
- May 2, 2023: SBIA Webinar: Navigating the First ICH Generic Drug Draft Guideline “M13A Bioequivalence for Immediate-Release Solid Oral Dosage Forms”
- May 10, 2023: FDA/CRCG Training: Drug-Device Combination Products 101: Identifying, Developing, and Evaluating Drug-Device Combination Products
- May 11 – 12, 2023: Fiscal Year 2023 Generic Drug Science and Research Initiatives Public Workshop
- May 15, 2023: SBIA Webinar: A Deep Dive: GDUFA III Scientific Meetings
- June 15, 2023: FDA/CRCG Workshop: Mitigation Strategies for Nitrosamine Drug Substance Related Impurities: Quality and Bioequivalence Considerations for Generics
Guidance documents represent FDA's current thinking on a topic and may discuss more specific products or issues that relate to the design, production, labeling, promotion, manufacturing, and testing of regulated products. Below is a list of recently published guidances and other documents related to complex generics.
Product-specific guidances (PSGs) provide recommendations for developing generic drugs and generating the evidence needed to support abbreviated new drug application (ANDA) approval, thereby helping to streamline generic drug product development by industry and ANDA assessment by FDA.
- In May 2023, FDA published 47 draft PSGs, of which 25 were for complex products (14 new and 11 revised). FDA also updated the Upcoming Product-Specific Guidances for Generic Drug Product Development web page, which is updated each time FDA publishes a new batch of PSGs.
- In May 2023, FDA published an update to Manual of Policies and Procedures (MAPP) “Assessment of Bioequivalence Studies with Clinical Endpoints in ANDAs” (MAPP 5210.4 Rev. 3).
- In April 2023, FDA published two revised draft guidances related to the design and conduct of studies for evaluating transdermal and topical delivery systems (TDS) submitted abbreviated new drug applications (ANDAs):
FDA’s GDUFA Science and Research Program provides new tools for FDA to evaluate generic drug equivalence and for industry to efficiently develop new generic products. Below are recent FDA articles focusing on complex generics.
- Increasing Impact of Quantitative Methods and Modeling in Establishment of Bioequivalence and Characterization of Drug Delivery
- Establishing the Suitability of Model-Integrated Evidence to Demonstrate Bioequivalence for Long-Acting Injectable and Implantable Drug Products: Summary of Workshop
- Regulatory Utility of Mechanistic Modeling to Support Alternative Bioequivalence Approaches: A Workshop Overview
- Product Quality Research for Developing and Assessing Regulatory Submissions for Generic Cyclosporine Ophthalmic Emulsions
- Development of In Vitro-In Vivo Correlations for Long-Acting Injectable Suspensions. International Journal of Pharmaceutics
- The Role of Capsule Aperture Size on the Dispersion of Carrier-based Formulation at Different Air Flowrates
- Investigating Structural Attributes of Drug Encapsulated Microspheres with Quantitative X-ray Imaging
- Topical Pharmacokinetics of Brinzolamide Suspensions in Rabbits and Variability Analysis for Sample Size and Design Considerations
Further information on complex generics is available at the links below.
- The Center for Research on Complex Generics
- Product-Specific Guidances for Generic Drug Development
- Upcoming Product-Specific Guidances for Generic Drug Product Development
- GDUFA Science and Research
- Generic Drug Research Priorities and Projects
- FDA Drug Competition Action Plan
- Infographic GDUFA III – Summary of T-Cons and Meetings (PDF - 117 KB)