Norfloxacin is a first-generation synthetic fluoroquinolone antibiotic.
| Mechanism of Action | Norfloxacin indirectly inhibits DNA gyrase by binding to nearby DNA substrate. DNA gyrase is an essential DNA replication enzyme which reduces DNA strain during active DNA replication. Norfloxacin is most active in the pH range between 4.5 and 6.5. |
| Spectrum | Norfloxacin is a broad spectrum antibiotic commonly used to target bacteria responsible for urinary tract infections. |
| Impurity Profile | Impurity A| 7-Chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic Acid|||| Impurity D| 1-Ethyl-6-fluoro-7-(piperazin-1-yl)quinolin-4(1H)-one|||| Impurity G| 1-Ethyl-6-fluoro-7-(4-formylpiperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic Acid 1-Ethyl-6-fluoro-7-(4-formylpiperazin-1-yl)-4-oxo-1,4-dihydro|||| Impurity F| Chloro analogue of Norfoxacin|||| |
| Microbiology Applications | Norfloxacin 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 for infected patients. Representative MIC values include:
Media Supplements:Norfloxacin can be used as a selective agent in several types of isolation media: Clostridium difficile Agar - CDMN Selective Supplement |
| Molecular Formula | C16H18FN3O3 |
| Solubility | Acetone: 5.1 mg/mL Chloroform: 5.5 mg/mL Glacial acetic acid: Freely soluble Water: 0.28 mg/mL Acids and bases: Soluble at pH <5 and >10 |
| References | Wolfson, John S., and David C. Hooper. "The Fluoroquinolones: Structures, Mechanisms of Action and Resistance, and Spectra of Activity in Vitro." American Society for Microbiology 4th ser. 28 (1985): 581-86. Shen, Linus L., and Andre G. Pernet. "Mechanism of Inhibition of DNA Gyrase by Analogues of Nalidixic Acid: The Target of the Drugs Is DNA." PNAS 82 (1985): 307-11. Pnas.org. Web. 4 June 2013. |
| MIC | Bacillus spp. (MTCC 297)| ≤1|| Bacillus subtilis| 0.049 － 10|| Bacteroides bivius| ≥1.56|| Bacteroides distasonis| ≥12.5|| Bacteroides fragilis| 16 － 25|| Bacteroides intermedius| 3.13|| Bacteroides oralis| 3.13|| Bacteroides oris (ATCC 33573)| 3.13|| Bacteroides ovatus| ≥100|| Bacteroides thetaiotaomicron| ≥200|| Bacteroides uniformis| ≥50|| Bacteroides ureolyticus| ≥0.2|| Bacteroides vulgatus| ≥100|| Bifidobacterium adolescentis| ≤0.025|| Bordetella bronchiseptica| 1 － 8|| Borrelia burgdorferi S.L.| 1 － 16|| Burkholderia mallei | 2 － 4|| Capnocytophaga ochracea| ≤0.025|| Chlamydia pneumonia| ≥16|| Chlamydia psittaci| ≥16|| Chlamydia trachomatis| 25|| Citrobacter freundii| 0.39 － 1|| Clostridium difficile| ≥50|| Clostridium perfringens| ≥3.13|| Clostridium septicum| ≥0.78|| Clostridium spiroforme| 8 － 64|| Corynebacterium| <1|| Corynebacterium diphtheriae| ≥0.39|| Enterobacter aerogenes| 0.2 － 256|| Enterobacter cloacae| 0.125 － >256|| Enterococcus faecalis| 1.56 － 66|| Escherichia coli| 0.016 － >128|| Eubacterium lentum| ≥6.25|| Fusobacterium mortiferum| ≥6.25|| Fusobacterium varium| ≥50|| Hafnia alvei| ≥0.1|| Helicobacter pylori| 0.05 － 25|| Klebsiella pneumonia| 0.049 － 43|| Klebsiella spp.| ≤1|| Lactobacillus acidophilus| 500 － >1000|| Lactobacillus gasseri| >1000|| Lactobacillus johnsonii | ≥750|| Lactobacillus paracasei| ≥1000|| Lactobacillus reuteri| ≥1000|| Lactobacillus salivarius| ≥250|| Micrococcus luteus | ≥12.5|| Morganella morganii| ≥0.2|| Mycobacterium africanum| ≥2|| Mycobacterium bovis| ≥4|| Mycobacterium tuberculosis| 2 － 31.2|| Neisseria meningitidis| ≥0.025|| Peptostreptococcus anaerobius| ≥6.25|| Peptostreptococcus asaccharolyticus| ≥6.25|| Peptostreptococcus magnus| ≥0.78|| Peptostreptococcus prevotii| ≥6.25|| Proteus mirabilis| ≥0.1|| Proteus spp.| ≤1|| Proteus vulgaris| ≥0.1|| Providencia inconstans| ≥0.2|| Providencia rettgeri| ≥0.78|| Pseudomonas aeruginosa| 0.2 － 64|| Salmonella Binza| ≥0.06|| Salmonella enteritidis| 0.05 － 1|| Salmonella Hadar| ≥0.06|| Salmonella Haifa| ≥0.06|| Salmonella Heidelberg| ≥0.06|| Salmonella Kedougou| ≥0.06|| Salmonella Mbandaka| ≥0.06|| Salmonella Montevideo| ≥0.06|| Salmonella Newport| ≥0.06|| Salmonella Paratyphi| ≥0.05|| Salmonella sp.| ≥1|| Salmonella typhi| 0.025 － 11|| Salmonella typhimurium| 0.06 － 0.25|| Salmonella Virchow| ≥0.06|| Salmonella Weltevreden| ≥33|| Serratia marcescens| 0.2 － 0.39|| Shigella boydii | ≥0.1|| Shigella dysenteriae| ≥0.05|| Shigella flexneri | ≤0.006 － 0.2|| Shigella sonnei| ≥0.1|| Staphylococcus asaccharolyticus| ≥0.78|| Staphylococcus aureus| 0.39 － 2048|| Staphylococcus epidermidis| 0.5 － 1.56|| Staphylococcus pyogenes| ≥10|| Stenotrophomonas maltophilia| 4 － 64|| Streptococcus intermedius| ≥12.5|| Streptococcus pneumonia| 0.39 － 32|| Streptococcus pyogenes| 0.78 － 1.56|| Streptococcus spp.| ≥1.56|| Veillonella parvula| ≥0.78|| Vibrio cholerae| 10 － 120|| Vibrio parahaemolyticus| ≥120|| |