FDA Orange Book · active-ingredient family
Chlorzoxazone
Chlorzoxazone: 2 brands, 36 generics; first approved Aug 09, 1982; generic available.
Generic availableHas discontinued products
Generic status & protection
Generic available: 36 ANDA applications approved.
Brands (NDA)
2
Generics (ANDA)
36
Listed patents
0
Presentations
53
Brand (NDA) products
Originator applications
- JANSSEN R AND DNDA 0115291987
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - PARAFLEXRLDORTHO MCNEIL PHARMNDA 011300—
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued —
Generic (ANDA) products (36)
Abbreviated applications
- CHLORZOXAZONESENORES PHARMSANDA 2109612024
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Rx AA - CHLORZOXAZONEAUROBINDO PHARMA LTDANDA 08985320233 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Rx AA 375MG TABLET ORAL Rx AB 750MG TABLET ORAL Rx AB - CHLORZOXAZONERISINGANDA 2169252023
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Rx AA - CHLORZOXAZONEACME LABSANDA 2143652023
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONECOREPHARMAANDA 2147022023
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Rx AA - CHLORZOXAZONESOMERSET THERAPS LLCANDA 21204720232 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Rx AB 750MG TABLET ORAL Rx AB - CHLORZOXAZONEAJENAT PHARMSANDA 2155402023
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Rx AA - CHLORZOXAZONECOREPHARMAANDA 21494120223 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Rx AB 500MG TABLET ORAL Rx AA 750MG TABLET ORAL Rx AB - CHLORZOXAZONERISINGANDA 21312620223 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Rx AB 500MG TABLET ORAL Rx AA 750MG TABLET ORAL Rx AB - CHLORZOXAZONESENORES PHARMSANDA 2151582021
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Rx AA - CHLORZOXAZONEPH HEALTHANDA 21274320212 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 750MG TABLET ORAL Rx AB 375MG TABLET ORAL Rx AB - CHLORZOXAZONECHARTWELL RXANDA 21205320202 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Discontinued — 750MG TABLET ORAL Discontinued — - CHLORZOXAZONEDR REDDYS LABS SAANDA 21184920203 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Rx AB 500MG TABLET ORAL Rx AA 750MG TABLET ORAL Rx AB - CHLORZOXAZONETEVA PHARMS USA INCANDA 21289820202 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Discontinued — 750MG TABLET ORAL Discontinued — - CHLORZOXAZONEGLENMARK PHARMS LTDANDA 21218520202 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Discontinued — 750MG TABLET ORAL Discontinued — - CHLORZOXAZONENOVITIUM PHARMAANDA 21225320192 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Rx AB 750MG TABLET ORAL Rx AB - CHLORZOXAZONENOVITIUM PHARMAANDA 2122542019
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Rx AA - CHLORZOXAZONERSANDA REPOSITORYANDA 2074832016
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Rx AA - CHLORZOXAZONERSANDA REPOSITORYANDA 04086120102 strengths
Approved strengths under this FDA application. Strength Dosage form Route Status TE 375MG TABLET ORAL Rx AB 750MG TABLET ORAL Rx AB - CHLORZOXAZONEWATSON LABSANDA 0401371996
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONEACTAVIS ELIZABETHANDA 0401131995
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONEOHM LABSANDA 0812981993
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued — - CHLORZOXAZONEOHM LABSANDA 0812991993
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONEWATSON LABSANDA 0810191991
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONESUN PHARM INDUSTRIESANDA 0899701990
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONEWATSON LABSANDA 0810401989
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONEPIONEER PHARMSANDA 0895921989
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued — - CHLORZOXAZONEPIONEER PHARMSANDA 0899481989
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - FERNDALE LABSANDA 0810081988
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONEBARRANDA 0898951988
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Discontinued — - CHLORZOXAZONERISINGANDA 0898521988
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued — - CHLORZOXAZONERSWATSON LABSANDA 0898591988
Approved strengths under this FDA application. Strength Dosage form Route Status TE 500MG TABLET ORAL Rx AA - CHLORZOXAZONEACTAVIS ELIZABETHANDA 0889281987
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued — - CHLORZOXAZONECHARTWELL RXANDA 0879811983
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued — - CHLORZOXAZONEWATSON LABSANDA 0869481982
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued — - CHLORZOXAZONEWATSON LABSANDA 086901—
Approved strengths under this FDA application. Strength Dosage form Route Status TE 250MG TABLET ORAL Discontinued —
Listed patents
Orange Book patent file
No patents are listed against this product in the Orange Book. Listed patents reflect those the NDA holder submits under 21 U.S.C. 355 and are not exhaustive.
Approval history
FDA approval span
First approval
44 yr 8 mo ago
Most recent approval
2 yr 7 mo ago
Approvals span 1982–2024 across 38 FDA applications.
Brand (NDA) 25%
Generic (ANDA) 3695%
Chlorzoxazone: frequently asked questions
Generics, reference-listed drug, patents, and exclusivity for this active ingredient, from the FDA Orange Book.
Built directly from the FDA Orange Book data file (products, patents, and exclusivity). TE codes, RLD/RS flags, patent expirations, and exclusivity dates match the official FDA record. Listed patents reflect those the NDA holder submits under 21 U.S.C. 355 and are not exhaustive.
Related FDA reference tools
- FDA Purple BookLicensed biologics, biosimilars, interchangeables, BLA records, and exclusivity dates.
- FDA BiosimilarsFDA-approved biosimilars and interchangeable biosimilars, by reference product.
- 510(k) Predicate DatabaseSearch FDA 510(k) clearances and map predicate-device lineage.
- FDA 483 DatabaseFDA Form 483 observations and inspection records by firm, date, and citation.
