Product-Specific Guidances for Generic Drug Development

Disclaimer: Due to April 2019 systemwide upgrades to, the filenames for product-specific guidances on this web page may not match the corresponding guidance titles. In such cases, the name on the document correctly identifies the title of the guidance. These discrepancies will be corrected as soon as possible.

To successfully develop and manufacture a generic drug product, an applicant should consider that their product is expected to be: pharmaceutically equivalent 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 have the same safety and efficacy as its reference listed drug.

According to 21 CFR 320.24, different types of evidence may be used to establish bioequivalence for pharmaceutically equivalent drug products, including in vivo or in vitro testing, or both. The selection of the method used to demonstrate bioequivalence depends upon the purpose of the study, the analytical methods available, and the nature of the drug product. Under this regulation, applicants must conduct bioequivalence 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initial step for selecting methodology for generic drug product development, applicants are referred to the following draft guidance: Draft Guidance for Industry on Bioequivalence Studies With Pharmacokinetic Endpoints for Drugs Submitted Under an Abbreviated New Drug Application (ANDA) (August 2021).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 further facilitate generic drug product availability and to assist the generic pharmaceutical industry with identifying the most appropriate methodology for developing drugs and generating evidence needed to support ANDA approval, FDA publishes product-specific guidances describing the Agency's current thinking and expectations on how to develop generic drug products therapeutically equivalent to specific reference listed drugs.

FDA publishes these product-specific guidances to foster drug product development, and ANDA submission and approval, ultimately providing increased access to safe, affordable generic drugs.

These guidances 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.

Additionally, as part of FDA's commitments under the Generic Drug User Fee Amendments Reauthorization of 2017 (GDUFA II), FDA will publish guidances for reference listed drugs that are (1) new chemical entities and (2) approved on or after October 1, 2017, at least 2 years prior to the earliest lawful ANDA filing date. 1 This goal does not include complex products as defined in the GDUFA II Commitment Letter. FDA will strive to issue guidance for a complex product as soon as scientific recommendations are available.

In addition to the provided information, sponsors and investigators of any Investigational New Drug (IND)-exempt pharmacokinetic (PK) studies, pharmacodynamic (PD) studies, or bioequivalence (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 product-specific guidances 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 Questions regarding submission of datasets to CDER may be sent to

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 the website ( 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 Help Desk at 1-877-378-5457 (toll free) for assistance regarding submissions.

The FDA posts plans for issuing new or revised product-specific guidances on the Upcoming Product-Specific Guidances for Complex Generic Drug Product Development web page.

For additional information on development of generic drug products, please refer to FDA’s biopharmaceutics guidances.

1GDUFA Reauthorization Performance Goals and Program Enhancements Fiscal Years 2018-2022 (GDUFA II Commitment Letter)




Total number of currently published PSGs: 1921

Product-Specific Guidances for Specific Products Arranged by Active Ingredient

Search by Active Ingredient or by RLD or RS Number

68 record(s) found for 'O'

Active Ingredient (link to Specific Guidance) URL Type Route Dosage Form RLD or RS Number Date Recommended
Obeticholic Acid acid_oral tablet_NDA 207999_RC05-17.pdf Draft Oral Tablet 207999 07/2017
Octreotide Acetate acetate_inj_21008_RV02-14.pdf Draft Injection Injectable 021008 02/2014
Octreotide Acetate Draft Oral Capsule, Delayed Release 208232 03/2021
Octreotide Acetate Draft Subcutaneous Solution 213224 03/2021
Ofloxacin solution drops_NDA 019921_RV08-17.pdf Draft Ophthalmic Drops, Solution 019921 10/2017
Olanzapine Draft Oral Tablet 020592 08/2008
Olanzapine Final Oral Tablet, Orally Disintegrating 021086 05/2008
Olanzapine Pamoate ER suspension_RLD22173_RC01-16.pdf Draft Intramuscular Suspension, Extended Release 022173 01/2016
Olaparib capsule_NDA 206162_RC08-17.pdf Draft Oral Capsule 206162 10/2017
Olaparib Oral Tablet NDA 208558 RC 09-2018.pdf Draft Oral Tablet 208558 09/2018
Olive Oil; Soybean Oil oil; Soybean Oil injectable injection RLD 204508 RC 09-2018.pdf Draft Injection Injectable 204508 09/2018
Olmesartan Medoxomil Final Oral Tablet 021286 05/2008
Olodaterol Hydrochloride Draft Inhalation Spray, Metered 203108 08/2021
Olodaterol Hydrochloride; Tiotropium Bromide Draft Inhalation Spray, Metered 206756 07/2021
Olopatadine Hydrochloride HCl_ophthalmic solution_NDA 021545_RV08-17.pdf Draft Ophthalmic Solution, Drops 0.2% 021545 10/2017
Olopatadine Hydrochloride hydrochloride_ophthalmic solution_NDA 020688_RV08-17.pdf Draft Ophthalmic Solution, Drops 0.1% 020688 10/2017
Olopatadine Hydrochloride HCl_nasal metered spray_RLD 021861_RC09-16.pdf Draft Nasal Spray, Metered 021861 10/2016
Olopatadine Hydrochloride hydrochloride_ophthalmic solution_NDA 206276_RC11-17.pdf Draft Ophthalmic Drops, Solution 206276 02/2018
Olsalazine Sodium Draft Oral Capsule 019715 03/2020
Omadacycline Tosylate Draft Oral Tablet 209816 11/2019
Omadacycline Tosylate Draft Intravenous Powder 209817 11/2019
Ombitasvir; Paritaprevir; Ritonavir tablet_RLD 207931_RC06-16.pdf Draft Oral Tablet 207931 06/2016
Omega 3 Acid Ethyl Esters Draft Oral Capsule 021654 08/2020
Omega3 Acid Ethyl Esters Type A Ethyl Esters_oral capsule_RLD 204977_RC12-16.pdf Draft Oral Capsule 204977 12/2016
Omega3 Carboxylic Acids Carboxylic Acids_oral capsule_RLD 205060_RV12-16.pdf Draft Oral Capsule 205060 12/2016
Omeprazole Draft Oral Tablet, Delayed Release 022032 09/2012
Omeprazole Draft Oral Capsule, Delayed Release 019810 11/2010
Omeprazole disintegrating DR tablet_NDA 209400_RC07-18.pdf Draft Oral Tablet, Orally Disintegrating, Delayed Release 209400 07/2018
Omeprazole Magnesium Final Oral Tablet, Delayed Release 021229 05/2008
Omeprazole Magnesium magnesium oral delayed release suspension NDA 022056 PSG Page RC May 2019.pdf Draft Oral Granules, Delayed Release 022056 05/2019
Omeprazole; Sodium Bicarbonate bicarbonate_Oral suspension_022283_RC06-15.pdf Draft Oral Suspension, Powder 022283 06/2015
Omeprazole; Sodium Bicarbonate;_Sodium Bicarbonate_cap_21849_RC7-08.pdf Draft Oral Capsule 021849 07/2008
Omeprazole; Sodium Bicarbonate Draft Oral Suspension 021636 07/2009
Ondansetron Final Oral Tablet, Orally Disintegrating 020781 05/2008
Ondansetron Draft Oral Film 022524 03/2012
Ondansetron Hydrochloride Final Oral Tablet 020103 05/2008
Orlistat Draft Oral Capsule 020766 021887 08/2021
Orphenadrine Citrate Citrate_ERtabs_40327_RC04-10.pdf Draft Oral Tablet, Extended Release 012157 04/2010
Oseltamivir Phosphate Draft Oral Capsule 021087 12/2009
Oseltamivir Phosphate susp_21246_RV03-15.pdf Draft Oral Suspension 021246 03/2015
Osilodrostat Phosphate Draft Oral Tablet 212801 08/2021
Osimertinib Mesylate mesylate_oral tablet_NDA 208065_RC08-17.pdf Draft Oral Tablets 208065 10/2017
Ospemifene Draft Oral Tablet 203505 07/2014
Oxaprozin tablet_RLD 18841_RC04-16.pdf Draft Oral Tablet 018841 04/2016
Oxcarbazepine Draft Oral Tablet, Extended Release 202810 07/2014
Oxcarbazepine Final Oral Suspension 021285 05/2008
Oxcarbazepine Final Oral Tablet 021014 05/2008
Oxiconazole Nitrate Nitrate Cream NDA 019828 RV Feb 2019.pdf Draft Topical Cream 019828 02/2019
Oxiconazole Nitrate Nitrate Lotion NDA 020209 RV Feb 2019.pdf Draft Topical Lotion 020209 02/2019
Oxybutynin Draft Transdermal Film, Extended Release 202211 11/2019
Oxybutynin Transdermal metered gel_202513_RC06-15.pdf Draft Transdermal Gel, Metered 202513 06/2015
Oxybutynin Draft Transdermal Film, Extended Release 021351 11/2019
Oxybutynin Chloride chloride_transdermal gel 10_RLD 22204_RC04-16.pdf Draft Transdermal Gel 022204 04/2016
Oxybutynin Chloride Chloride_Oral tab_075079_RC03-15.pdf Draft Oral Tablet 075079 03/2015
Oxybutynin Chloride 20897_RV11-13.pdf Draft Oral Tablet, Extended Release 020897 11/2013
Oxycodone oral ER capsule NDA 208090 RV 09-2018.pdf Draft Oral Capsule, Extended Release 208090 09/2018
Oxycodone Hydrochloride hydrochloride_oral capsule_200534_RC06-15.pdf Draft Oral Capsule 200534 06/2015
Oxycodone Hydrochloride hydrochloride_oral ER tablet_NDA 022272_RV07-18.pdf Draft Oral Tablet, Extended Release 022272 07/2018
Oxycodone hydrochloride hydrochloride oral tablet NDA 209777 RC 09-2018.pdf Draft Oral Tablet 209777 09/2018
Oxycodone Hydrochloride Draft Oral Tablet 021011 12/2009
Oxymetazoline Hydrochloride Draft Topical Cream 208552 11/2019
Oxymetazoline Hydrochloride; Tetracaine Hydrochloride hydrochloride Tetracaine HCL_nasal spray_RLD 208032_RC03-17.pdf Draft Nasal Spray 208032 05/2017
Oxymetholone Draft Oral Tablet 016848 02/2011
Oxymorphone Hydrochloride HCl_oral ER tablet_RLD 201655_RC09-16.pdf Draft Oral Tablet, Extended Release 201655 10/2016
Oxymorphone Hydrochloride Draft Oral Tablet 021611 01/2008
Oxymorphone Hydrochloride Draft Oral Tablet, Extended Release 021610 02/2010
Ozanimod Hydrochloride Draft Oral Capsule 209899 08/2021
Ozenoxacin topical cream NDA 208945 RC 2019.pdf Draft Topical Cream 208945 02/2019

Newly Added Guidances since August 2021

Active Ingredient (link to Specific Guidance) URL Type Route Dosage Form RLD or RS Number Date Recommended
Acyclovir Draft Ophthalmic Ointment 202408 08/2021
Albuterol Sulfate; Ipratropium Bromide Draft Inhalation Spray, Metered 021747 08/2021
Amisulpride Draft Intravenous Solution 209510 08/2021
Avapritinib Draft Oral Tablet 212608 08/2021
Carbinoxamine Maleate Draft Oral Tablet 008915 08/2021
Cefiderocol Sulfate Tosylate Draft Intravenous Powder 209445 08/2021
Copper Dotatate Cu-64 Draft Intravenous Solution 213227 08/2021
Esomeprazole Magnesium Draft Oral Tablet, Orally Disintegrating, Delayed Release 214278 08/2021
Estradiol Draft Transdermal Gel, Metered 021166 08/2021
Ethinyl Estradiol; Levonorgestrel Draft Transdermal System 204017 08/2021
Fostemsavir Tromethamine Draft Oral Tablet, Extended Release 212950 08/2021
Indomethacin Draft Rectal Suppository 017814 08/2021
Ipratropium Bromide Draft Nasal Spray, Metered 020393 020394 08/2021
Lasmiditan Succinate Draft Oral Tablet 211280 08/2021
Leuprolide Acetate Draft Subcutaneous Powder 021343 08/2021
Loteprednol Etabonate Draft Ophthalmic Gel 208219 08/2021
Olodaterol Hydrochloride Draft Inhalation Spray, Metered 203108 08/2021
Osilodrostat Phosphate Draft Oral Tablet 212801 08/2021
Ozanimod Hydrochloride Draft Oral Capsule 209899 08/2021
Paliperidone Palmitate Draft Intramuscular Suspension, Extended Release 207946 08/2021
Semaglutide Draft Oral Tablet 213051 08/2021
Sufentanil Citrate Draft Sublingual Tablet 209128 08/2021
Tazemetostat Hydrobromide Draft Oral Tablet 211723 08/2021

Newly Revised Guidances since August 2021

Active Ingredient (link to Specific Guidance) URL Type Route Dosage Form RLD or RS Number Date Recommended
Bexarotene Draft Oral Capsule 021055 08/2021
Budesonide Draft Oral Capsule, Delayed Release 021324 08/2021
Eltrombopag Olamine Draft Oral Tablet 022291 08/2021
Eltrombopag Olamine Draft Oral For Suspension 207027 08/2021
Ferric Citrate Draft Oral Tablet 205874 08/2021
Ferric Oxyhydroxide Draft Oral Tablet, Chewable 205109 09/2021
Ferric Oxyhydroxide Draft Intravenous Injectable 021135 09/2021
Letrozole Draft Oral Tablet 020726 08/2021
Leuprolide Acetate Draft Injection Injectable 019732 020011 020263 08/2021
Leuprolide Acetate Draft Injection Injectable 020517 020708 08/2021
Liothyronine Sodium Draft Oral Tablet 010379 08/2021
Loteprednol Etabonate Draft Ophthalmic Suspension/Drops 020583 08/2021
Nystatin Draft Topical Powder 065203 08/2021
Orlistat Draft Oral Capsule 020766 021887 08/2021
Paclitaxel Draft IV Infusion For Suspension 021660 08/2021
Podofilox Draft Topical Gel 020529 08/2021
Sodium Zirconium Cyclosilicate Draft Oral For Suspension 207078 08/2021
Tazarotene Draft Topical Cream 0.05% 021184 08/2021

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