Evaluation of the in vitro ocular toxicity of the fortified antibiotic eye drops prepared at the Hospital Pharmacy Departments Evaluación de la toxicidad ocular in vitro de los colirios fortificados antibióticos elaborados en los Servicios de Farmacia Hospitalaria

The use of parenteral antibiotic eye dr op formulations with non-marketed compositions or concentrations, commonly called fortified antibiotic eye drops, is a common practice in Ophthalmology in the hospital setting. The aim of this study was to evaluate the in vitro ocular toxicity of the main fortified antibiotic eye drops prepared in the Hospital Pharmacy Departments. We have conducted an in vitro experimental study in order to test the toxicity of gentamicin, amikacin, cefazolin, ceftazidime, vancomycin, colistimethate sodium and imipenem-cilastatin eye drops; their cytotoxicity and acute tissue irritation have been evaluated. Cell-based assays were performed on human stromal keratocytes, using a cell-based impedance biosensor system [xCELLigence Real-Time System Cell Analyzer (RTCA)], and the Hen’s Egg Test for the ocular irritation tests. All the eye drops, except for vancomycin and imipenem, have shown a cytotoxic ef fect dependent on concentration and time; higher concentrations and longer exposure times will cause a steeper decline in the population of stromal keratocytes. Vancomycin showed a major initial cytotoxic effect,