Title: Norfloxacin
CAS Registry Number: 70458-96-7
CAS Name: 1-Ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid
Manufacturers' Codes: AM-715; MK-366
Trademarks: Baccidal (Kyorin); Barazan (Merck & Co.); Chibroxin(e) (Merck & Co.); Chibroxol (Merck & Co.); Floxacin (Merck & Co.); Fulgram (ABC); Gonorcin (Farmas); Lexinor (Astra); Noflo (Merck & Co.); Nolicin (Krka); Noracin (Chew); Norocin (Merck & Co.); Noroxin(e) (Merck & Co.); Norxacin (Siam Bheasach); Sebercim (ISF-Italseber); Uroxacin (Lazar); Utinor (Merck & Co.); Zoroxin (Merck & Co.)
Molecular Formula: C16H18FN3O3
Molecular Weight: 319.33
Percent Composition: C 60.18%, H 5.68%, F 5.95%, N 13.16%, O 15.03%
Literature References: Fluorinated quinolone antibacterial. Prepn: T. Irikura,
BE 863429;
eidem, US 4146719 (1978, 1979 both to Kyorin); M. Pesson,
DE 2840910;
eidem, US 4292317 (1979, 1981 both to Roger Bellon/Dainippon); H. Koga
et al., J. Med. Chem. 23, 1358 (1980). Comparative antibacterial activity: K. Hirai
et al., Antimicrob. Agents Chemother. 19, 188 (1981); M. Y. Khan
et al., ibid. 265; H. H. Gadebusch
et al., Infection 10, 41 (1982). Series of articles on
in vivo and
in vitro activity, pharmacology, pharmacokinetics, metabolism, early clinical studies, toxicology:
Chemotherapy (Tokyo) 29, Suppl. 4, 1-1000 (1981). Acute toxicity data: T. Irikura
et al., ibid. 783.
In vitro activity vs gentamicin-resistant
P. aeruginosa: J. Downs
et al., Antimicrob. Agents Chemother. 21, 670 (1982). Treatment of lower urinary tract infection: H. Giamarellou
et al., Eur. J. Clin. Microbiol. 2, 266 (1983); of penicillin-resistant gonorrhea: S. R. Crider
et al., N. Engl. J. Med. 311, 137 (1984). Review of pharmacokinetics, antibacterial activity, clinical trials: B. Holmes
et al., Drugs 30, 482-513 (1985); R. C. Rowen
et al., Pharmacotherapy 7, 92-110 (1987). Symposium on clinical experience:
Scand. J. Infect. Dis. Suppl. 48, 1-91 (1986). Comprehensive description: C. Mazuel,
Anal. Profiles Drug Subs. 20, 557-600 (1991).
Properties: White to light-yellow crystalline powder, mp 220-221°. uv max (0.1
N NaOH): ~274, 325, 336 nm (A1%1cm ~1109, 437, 425). pKa1 6.34; pKa2 8.75. Partition coefficient (octanol/water): 0.46. Soly at 25° (mg/ml): water 0.28; methanol 0.98; ethanol 1.9; acetone 5.1; chloroform 5.5; diethyl ether 0.01; benzene 0.15; ethyl acetate 0.94; octyl alcohol 5.1; glacial acetic acid 340. Solubility in water is pH dependent, increasing sharply at pH <5 or at pH >10. Hygroscopic in air, forms a hemihydrate. LD50 in mice, rats (mg/kg): >4000 orally (both species); 1500 s.c. (both species); 470, >500 i.m.; 220, 270 i.v. (Irikura).
Melting point: mp 220-221°
pKa: pKa1 6.34; pKa2 8.75
Log P: Partition coefficient (octanol/water): 0.46
Absorption maximum: uv max (0.1
N NaOH): ~274, 325, 336 nm (A1%1cm ~1109, 437, 425)
Toxicity data: LD50 in mice, rats (mg/kg): >4000 orally (both species); 1500 s.c. (both species); 470, >500 i.m.; 220, 270 i.v. (Irikura)
Therap-Cat: Antibacterial.
Keywords: Antibacterial (Synthetic); Quinolones and Analogs.