Aqueous Humor Concentrations of Topically Applied Fluoroquinolones

Abstract

Abstract: : Purpose: To compare the aqueous humor concentrations of three commercially available ophthalmic fluoroquinolones. Methods: Forty–three consecutive patients undergoing cataract extraction were randomly assigned to receive either 0.3% ciprofloxacin (Ciloxan^TM ), 0.5% levofloxacin (Quixin^TM), or 0.3% ofloxacin (Ocuflox^TM) topical ophthalmic drops. All patients signed informed consent forms, which explained the nature of the study. The patients (14 ciprofloxacin, 14 levofloxacin and 15 ofloxacin) were instructed to use their antibiotic drops four times a day for 3 days prior to surgery. On the day of surgery, patients were given their assigned antibiotic every 15 minutes for one hour prior to their procedure. At the time of surgery, 0.1 ml of aqueous fluid was aspirated from the anterior chamber via an air cannula needle attached to a tuberculin syringe. This was immediately stored at –70 degrees Centigrade in a sub–zero refrigerator (Tafco Incorporated Model # 12–11–F–NR). Concentrations of ciprofloxacin, levofloxacin, and ofloxacin were determined by using reversed phase high–pressure liquid chromatography assay technique with ultraviolet detection at a wavelength of 275 nm. Results: Mean aqueous humor concentrations of the fluoroquinolones were 0.3079 mcg/ml + 0.619 for ofloxacin, 0.1143 mcg/ml +0.0367 for ciprofloxacin, and 0.4876 mcg/ml + 0.792 for levofloxacin. Conclusions: Topically applied ciprofloxacin penetrates the anterior chamber less well than ofloxacin and levofloxacin. The mean aqueous concentration of levofloxacin was significantly greater than ofloxacin (p<0.05) and ciprofloxacin (p<0.001). The anterior chamber levels of levofloxacin and ofloxacin may be due to the difference in antibiotic concentration and may not reflect an intrinsic difference in solubility.

Keywords: antibiotics/antifungals/antiparasitics • clinical research methodology • pharmacology