Ole J. Lorenzetti

Ocular Bioavailability of Ciprofloxacin in Sustained Release Formulations

A novel sustained release delivery system of ciprofloxacin for the eye was developed. The system consists of a viscosity enhancer (carbopol gel or hydroxypropylmethylcellulose solution) plus a penetration enhancer (dodecylmaltoside) to overcome penetration barriers and loss due to wash-out and thus achieve the desired ciprofloxacin ocular absorption. The present studies were designed to assess the ocular penetration and bioavailability of ciprofloxacin in sustained release formulations. In vitro studies in rabbits indicated an approximate 10-fold increase in drug penetration through the rabbit cornea using the penetration enhancer, dodecylmaltoside. In vivo bioavailability studies demonstrate that these formulations provided a long drug duration in the cornea. After administration of a single topical dose of ciprofloxacin (0.3%/30 microL), corneal levels greater than the Minimum Inhibitory Concentration (MIC90) (0.5 microg/g) were observed through eight hours. These sustained release formulations delivered 10-fold more drug into the aqueous humor than the standard solution formulation. Maximum ciprofloxacin concentrations in the aqueous humor (0.5-0.7 microg/mL) were attained between one and two hours after dosing. Using these sustained release formulations, ciprofloxacin can penetrate to the anterior chamber of the eye in concentrations that are inhibitory for most gram-negative and gram-positive organisms. These topical ocular formulations have prophylactic utility for prevention of post-surgical infection, offering greater efficacy and safety than currently available treatments.

Effect of BSS Plus on the Corneal Endothelium with Intraocular Lens Implantation

AbstractBSS Plus, a new intraocular irrigating solution, was compared to BSS (Balanced Salt Solution) in 100 cases of planned extracapsular cataract extraction with the insertion of a Simcoe posterior chamber intraocular lens. Surgery was standardized in all cases, and Healon was not used. Fifty patients received BSS Plus at surgery and 50 patients received BSS. Approximately 10–20 min of introcular irrigation was required for each case. Preoperative and postoperative corneal endothelial cell counts showed a decrease in cell density of 15.4% using BSS Plus, and a decrease of 22.7% using BSS. These differences were statistically significant (p < 0.05).