Determination of ciprofloxacin in ocular aqueous by HPLC
Comparison of topical and oral administration

Amir Heydari¹ – Vafa Samareyi²

¹Center for Cellular and Molecular Research,
²Department of Ophthalmology, Urmia University of Medical Sciences, Urmia, Iran

Fluoroquinolone is a widely used antibiotic for prophylaxis of intra and postoperative infections in individuals undergoing cataract surgery. This study was designed to assess the effectivness of ciprofloxacin therapy (topical vs. oral administration).

Studied population (n = 47) consisted of two groups: group one (n = 26) and group two (n = 21). Group one received eyedrop (one drop every six hrs for three days before surgery and on the day of surgery topical medication was administered every 30 min with the last drop instillation approximately 4 hrs before start of surgery). Group two received a combination of ciprofloxacin comparison of eyedrop therapy as describe above plus oral dose (500 mg/ twice a day of three days before operation).

Samples of aqueous humor were taken at the last administration of the drug. Ciprofloxcacin concentration was determined by HPLC with fluorescence detector.
Aqueous humor concentrations of ciprofloxacin in the patients who received combinations of eyedrops and oral administration doses (mean 0.95 µg/ml) were significantly higher than patients receiving only eyedrops (mean 0.23 µg/ml, P<0.001).

The results for first group (eyedrops) were below the MIC values of Staphylococcus epidermidis (0.58 µg/ml), MIC values of Pseudomonas oeroginosa (9.37 µg/ml) and MIC values of Streptocococcus pneumoniae (0.5-2 µg/ml). The results were over the MIC values of E.coli (0.14µg/ml). These results for the second group were over the MIC values of E.coli, Staphylococcus epidermidis and Streptocococcus pneumoniae and below the MIC values of Pseudomonas oeroginosa.

These results demonstrate that topical ciprofloxacin can penetrate into the aqueous humor but it alone dose not seem to be prophylactically effective against most of ocular pathogens. In most cases, combining the oral therapy with topical therapy increases the aqueous humor drug level and also efficacy significantly against most of ocular pathogens. This proposal is applicable for drug monitoring in patients undergoing prophylactic antibiotic therapy prior to surgery.