To successfully develop and manufacture a generic drug product, an applicant should consider that their product is expected to be: pharmaceuticallyequivalent to its reference listed drug (RLD), i.e., to have the same active ingredient, dosage form, strength, and route of administration under the same conditions of use; bioequivalent to the RLD, i.e., to show no significant difference in the rate and extent of absorption of the active pharmaceutical ingredient; and, consequently, therapeutically equivalent, i.e., to be substitutable for the RLD with the expectation that the generic product will be the same safety and efficacy as its RLD.

According to 21 CFR 320.24, different types of evidence may be used to establish bioequivalence (BE) for pharmaceutically equivalent drug products, including in vivo or in vitro testing, or both. The selection of the method used to demonstrate BE depends upon the purpose of the study, the analytical methods available, and the nature of the drug product. Under this regulation, applicants must conduct BE testing using the most accurate, sensitive, and reproducible approach available among those set forth in 21 CFR 320.24. As the initial step for selecting methodology for generic drug product development, applicants are referred to the following draft guidance: Draft Guidance for Industry on Bioequivalence Studies With Pharmacokinetic Endpoints for Drugs Submitted Under an Abbreviated New Drug Application (ANDA) (August 2021).

To facilitate generic drug product availability and further assist the generic pharmaceutical industry with identifying the most appropriate methodology for developing drugs and generating evidence needed to support ANDA approval, the FDA publishes product-specific guidances (PSG). End of
Translation PSGs describe the Agency's current thinking and expectations to develop generic drug products therapeutically equivalent to specific RLDs.

The FDA publishes PSGs to foster drug product development, ANDA submission and approval, and ultimately provide increased access to generic drugs.

PSGs are published in an incremental manner and listed below in alphabetical order according to the active ingredient's name. The most recently published guidances (new and revised) are listed below.

The implementation of FDA's commitments under the Generic Drug User Fee Amendments Reauthorization of 2022¹ (GDUFA III). with regard to issuance of PSGs is effective on October 1, 2022. Under GDUFA III, the FDA will issue PSGs consistent with the following goals:

• For complex products^1,2 approved in new drug applications (NDAs) on or after October 1, 2022, a PSG will be issued for 50 percent of such NDA products within two years after the date of approval, and for 75 percent of such NDA products within three years after the date of approval.
• FDA will continue to develop PSGs for complex products approved prior to October 1, 2022, for which no PSG has been published.
• For non-complex drug products approved in NDAs on or after October 1, 2022, that contain a new chemical entity (NCE) (as described in section 505(j)(5)(F)(ii) of the FD&C Act), a PSG will be issued within two years after the date of approval for 90 percent of such products.

In addition to GDUFA III PSG goals, the FDA considers several factors when prioritizing PSG development. The FDA evaluates the generic industries and other stakeholders' interest in products that do not have a PSG through controlled correspondences, public requests, and pre-ANDA meeting requests.

The FDA also evaluates drug availability and accessibility and considers public health priorities, including but not limited to, public health emergencies and drug safety and efficacy updates. In addition to these elements, the FDA continually assesses the status and outcomes of ongoing GDUFA research to ensure there are sufficient and adequate data and evidence to support the development of PSGs that align with the FDA's current scientific thinking.

Sponsors and investigators of any investigational new drug (IND)-exempt pharmacokinetic (PK) studies, pharmacodynamic (PD) studies, or BE and/or bioavailability (BA) studies involving human subjects in support of an ANDA should refer to the current RLD labeling, including BOXED WARNINGS, CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS sections. This information should be considered during study design and conduct, including attention to appropriate subject screening and selection, inclusion and exclusion criteria, and appropriate clinical safety monitoring.

In addition to the provided information, sponsors and investigators of any Investigational New Drug (IND)-exempt pharmacokinetic (PK) studies, pharmacodynamic (PD) studies, or BE and/or bioavailability (BA) studies involving human subjects in support of an ANDA should refer to the current RLD labeling, including BOXED WARNINGS, CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS sections. This information should be considered during study design and conduct; including attention to appropriate subject screening and selection, inclusion and exclusion criteria, and appropriate clinical safety monitoring.

Some of the PSGs include discussion regarding data formats. Please note that under section 745A(a) of the Federal Food, Drug, and Cosmetic Act, separate Agency-wide guidances specify the electronic formats, subject matter, and scope of applicability for certain submissions, including submissions to ANDAs. As these are finalized guidances and subject to described timetables for implementation, these guidances are binding and the electronic format(s) specified must be used for submissions to ANDAs. Questions and general information regarding the preparation of submissions in electronic format may be directed to CDER at esub@fda.hhs.gov. Questions regarding submission of datasets to CDER may be sent to edata@fda.hhs.gov.

COMMENTS: The Agency is seeking feedback and considers comments to the docket on these guidances. You may submit comments on any guidance at any time as follows: Submit electronic comments to Docket FDA-2007-D-0369. For further information on submitting electronic comments, refer to (www.regulations.gov). You may also mail your written comments to DDM (HFA-305), FDA, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852. All submissions received must include the Docket No. [FDA-2007-D-0369]. Please contact the Regulations.gov Help Desk at 1-877-378-5457 (toll free) or at (www.regulations.gov/support) for assistance regarding submissions.

The FDA posts plans for issuing new or revised PSGs on the Upcoming Product-Specific Guidances for Generic Drug Product Development web page

For additional information on development of generic drug products, please refer to FDA's guidance document database.

¹GDUFA Reauthorization Performance Goals and Program Enhancements Fiscal Years 2023-2027 (GDUFA III Commitment Letter)

²Classifying Approved New Drug Products and Drug-device combination Products as Complex Products for Generic Drug Development Purposes (CDER MAPP 5240.10)

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Product-Specific Guidances for Specific Products Arranged by Active Ingredient

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