Ciprofloxacin, oxidation

The sorption behaviour of antibiotics, in particular, can be very complex and therefore difficult to assess. As an example, ciprofloxacin has a log ATqw equal to 0.28, conferring it with a small tendency to leave the aquatic phase however, it does sorb well onto active sludge or sediments [62, 63] in WWTP. Tetracyclines (log A ow equal to 1.4), on the other hand, form complexes with double cations (calcium and magnesium) present in the water [64] and also tend to adsorb onto the surface of complexes between humic acids and hydrous Al oxide [65]. 

Gu C, Karthikeyan KG (2005) Sorption of the antimicrobial ciprofloxacin to aluminum and iron hydrous oxides. Environ Sci Technol 39 9166-9173... 

Robson RA, Begg EJ, Atkinson HC, et al. Comparative effects of ciprofloxacin and lomefloxacin on the oxidative metabolism of theophylline. Br J Clin Pharmacol 1990 29 491 193. 

Ciprofloxacin was determined in tablets and intravenous infusion solutions by an oxidative spectrophotometric method [15]. A yellow-orange complex was obtained upon reaction of ciprofloxacin with 5% ammonium sulfamate, 5 N H2S04, and 0.1 M cerium(IV) ammonium sulfate. The complex was extracted into CHC13, dried with anhydrous Na2S04, and measured at 345 nm within up to 4 h. Beer s law was obeyed over the range of 12-120 pg/mL, and the molar absorptivity was found to be 5090. 

The plasma concentration of olanzapine doubled in a patient who also took ciprofloxacin, a potent inhibitor of CYP1A2 (270). The magnitude of the interaction was surprising, because available data suggest that CYP1A2-mediated oxidation of olanzapine accounts for only a small portion of the biotransformation of olanzapine relative to glucuronidation. 

In vitro, pefloxacin was more toxic to tendons than ofloxacin, ciprofloxacin, or levofloxacin (3). In rodents, pefloxacin (400 mg/kg for several days) caused oxidative damage to the type I collagen in the Achilles tendon these alterations were identical to those observed in experimental tendinous ischemia and a reperfusion model (4). Oxidative damage was prevented by the co-administration of A-acetylcysteine (150 mg/kg). Several cases of rupture of the Achilles tendon have been reported during or shortly after the use of fluoroquinolones, including five case in which pefloxacin was used (5). 

Synthesis and antimicrobial activity of 3-formyl analogs of norfloxacin, ciprofloxacin, and pefloxacin have been reported [93]. These studies have shown definitive evidence that the 3-formyl analogs of quinolones function as prodrugs and are oxidized in vivo to carboxylic acids. The higher bioavailability of formyl derivatives may be due to a change in physical and chemical properties by the lack of their amphoteric nature, compared to the parent zwitterionic compounds. 

In complexes with antibiotics [amoxicillin, ampicillin, methiciUin, penicilUnG, cephalexin and ciprofloxacin (Figure 12.16, a-c)], polymeric compounds may be originated by direct reaction between dialkyltin(IV) chlorides and antibiotic sodium salt, or by direct reaction between trialkyltin(IV) hydroxides and free antibiotic acid. Other combinations (diorganotin oxide/free acid ligand triorganotin(IV) chloride/antibiotic salt) produce monomeric species. 

The determination of amoxicilline, ciprofloxacin, and piroxicam in bulk and pharmaceutical preparations has been performed by combining the oxidation character of Fe(III) with the chelation property of Fe(II), affording highly colored complexes. The reagent solutions are (1) a mixture of 1,10-phenanthroline and iron(III) ammonium sulfate in hydrochloride medium and (2) 2,2 -bipyridyl and iron(III) ammonium sulfate in hydrochloride medium. The resulting Fe(II) concentration, proportional to the amount of drug present, is monitored by the measurement of absorbances of tris(o-phenanthro-line) iron(U) or tris (bipyridyl) iron(II) complexes at 510 and 522 nm, respectively. 

The rate of chloramine B (CAB) oxidation of ciprofloxacin in H2O-HCI is first order in CAB, substrate, and H" " ion and is affected by ionic strength, dielectric constant, and added reaction product formation of an intermediate complex by the conjugate acid (PhS02NHCl) and substrate in the slow step has been proposed. ... 

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