Background It is essential to determine the safety of ophthalmic drugs.

Purpose To demonstrate any in vitro cytotoxicity of antifungal eye drops manufactured by the Hospital Pharmacy Department.

Material and methods Three antifungal eye drops (voriconazole 28.67 mM, fluconazole 6.53 mM and amphotericin 1.62 mM) were tested in Human Corneal Keratocytes (HCK). Toxicity to these cells was assessed using the novel label-free and real-time monitoring xCELLigence system. Under this platform, the Cell index (CI) was used to represent cell status based on the measurement of electrical impedance. Briefly, 3,000 cells/well (E-plates 16 wells) were seeded and incubated for 24 h until the CI reached the range of 1.0–1.2 indicating about 60% cell confluence. At this stage, cell culture medium was aspirated to perform cell treatment using different concentrations of antifungal eye drops. CI values were recorded throughout the test, obtaining real-time graphs of the cells’ behaviour in contact with the antifungal and IC50 was determined (corresponding to the concentrations of compounds that inhibit cell growth by 50% compared to controls).

Results The kinetic curves clearly showed that cellular response depends upon concentration and time in all antifungals tested. (These graphics will be displayed on the poster). The IC50 values obtained were 5.85 mM, 0.16 mM and 0.5 mM for voriconazole, amphotericin and fluconazole respectively.

Conclusion These results may be helpful in warning of cytotoxic effects of antifungal eye drops manufactured by Hospital Pharmacy Departments which are being used in concentrations that exceed the IC50 determined.

References and/or acknowledgements This work was supported by Fundación Española de Farmacia Hospitalaria and Fundación Mutua Madrileña

No conflict of interest.