• Ofloxacin packaged and labeled.

click on thumbnail to zoom
SKU: O001

  Click 'Bulk Order' for 10 or more
Price: make selection(s)

Ofloxacin is a synthetic, broad-spectrum, second-generation fluoroquinolone antibiotic.  It is an analog of nalidixic acid.  Ofloxacin inhibits the  supercoiling activity of bacterial DNA gyrase, halting DNA replication.  Ofloaxacin was developed by Daiichi Seiyaku to be resistant to metabolic oxidation in the liver.  It is used to combat organisms causing urinary tract and respiratory infections.

    CAS Number


    Molecular Formula


    Molecular Weight


    Mechanism of Action

    Ofloxacin is a Cytochrome P-450 inhibitor and DNA Topoisomerase II inhibitor.  Fluoroquinolone antibiotics target bacterial DNA gyrase, an enzyme which reduces DNA strain during replication. Because DNA gyrase is required during DNA replication, subsequent DNA synthesis and ultimately cell division is inhibited.

    Storage Conditions


    Tariff Code



    Ofloxacin is a broad-spectrum antibiotic targeting a wide range of Gram-positive and Gram-negative organisms.


    Cancer Applications

    Oflaxacin had an inhibitory effect on the proliferation of transitional cell carcinoma cell lines at high concentrations (>200 μg/ml).  The effect may be related to impairment of telomerase activity by some unknown mechanism (Yamakuchi M et al, 1997).

    Ofloxacin inhibited proliferation and DNA synthesis of these 3 human TCC lines (CCSUP, T24, and J82 ) in vitro. Inhibition occurred in a concentration- and time-dependent manner. Inhibition of proliferation and DNA synthesis were assessed via MTT and tritiated thymidine assays (Seay, 1996).

    Microbiology Applications

    Ofloxacin is commonly used in clinical in vitro microbiological antimicrobial susceptibility tests (panels, discs, and MIC strips) against Gram-positive and Gram-negative microbial isolates. Medical microbiologists use AST results to recommend antibiotic treatment options.  Representative MIC values include:

      • Haemophilus influenzae  0.016 µg/mL – 0.063 µg/mL
      • Escherichia coli  0.063 µg/mL – 0.125 µg/mL
      • For a complete list of Ofloxacin MIC values, click here.





    White crystalline powder



    Impurity Profile

    Impurity A| (RS)-9,10-Difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic Acid (FPA) ; Ofloxacin Difluoro Carboxylic Acid|82419-35-0|C13H9F2NO4|281.21| Impurity B| (RS)-9-Fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-2,3-dihydro-7H-pyrido-[1,2,3-de]-1,4-benzoxazin-7-one|||| Impurity E| (RS)-9-Fluoro-3-methyl-7-oxo-10-(piperazin-1-yl)-2,3-dihydro-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic Acid; N-Desmethyl Ofloxacin HCl|82419-52-1|C17H18FN3O4|347.34| Impurity F| 4-[(RS)-6-Carboxy-9-fluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de]-1,4-benzoxazine-10-yl]-1-methylpiperazine 1-Oxide Hydrochloride (Ofloxacin N-Oxide Acetate Salt)|104721-52-0|C20H24FN3O7|437.42| | Ofloxacin R-Isomer; (+)-(R)-9-Fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid ;(R)-(+)-Ofloxacin ;D-Ofloxacin ; Levofloxacin R-Isome|100986-86-5|C18H20FN3O4|361.37|

    Melting Point


    Optical Rotation

    -1° to +1°


    (On Dried Basis): 98.5-101.5%

    Loss on Drying




    Mouton Y and Leroy O (1991)  Ofloxacin. Int. J. Antimicrob. Agents 1(2-3):57-74

    Seay TM, Peretsman SJ and DIxon PS (1996)  Inhibition of human transitional cell carcinoma in vitro proliferation by fluoroquinolone antibiotics.  J. Urol. 2:757-762  PMID 8558720

    Smith JT (1991)  Ofloxacin, a bactericidal antibacterial. Chemother. 37 (supp 1):2-13  PMID 1646700

    Wolfson JS and Hooper DC. (1985)  The Fluoroquinolones: Structures, mechanisms of action and resistance, and spectra of activity in vitro. Antimicrob. Agents Chemother 28(4): 581-586.

    Yamakuchi M, Nakata M, Kawahara K, Kawahara K, Kitajima I and Maruyama I (1997)  New quinolones, ofloxacin and levofloxacin, inhibit telomerase activity in transitional cell carcinoma cell lines. Cancer Lett. 119(2):213-219  PMID  9570374

Other Items In This Category