Abstract
Purpose :
The combination of corticosteroid and antibiotic is the most commonly post-operative therapy use to prevent ocular infections. When the epithelial integrity is compromised the composition of the formulation, in terms of active ingredients and excipients, is important for the biocompatibility. The purpose of this study was to evaluate the potential cytotoxic effect of two different marketed preservative-free eye drops solutions containing corticosteroid and antibiotic.
Methods :
Human corneal epithelial cells (HCE) were repeatedly exposed (6 times) for 5 min (short time repeated exposure, S.T.R.E.) at 1.5h intervals to Netildex (0.3% netilmicin + 0.1% dexamethasone) or Betabioptal (0.5% chloramphenicol + 0.2% betamethasone) at two different concentrations: undiluted and 1:20 of the marketed concentration. Benzalkonium 0.01% was used as CTRL+. This protocol was designed to simulate the posology and the residence time of eyedrops considering blinking and tearing. Cell viability was assessed in wash and no wash condition by MTT assay. Statistics were by One-way ANOVA.
Results :
None of the products tested diluted (1:20) had any significant cytotoxic effect following S.T.R.E. protocol in both wash (Netildex 102.2%±4.3, Betabioptal 103.6%±3.2, respectively, as cell viability) and no wash conditions (Netildex 99.0% ±1.6, Betabioptal 101.2%±4.4, respectively, as cell viability). Interestingly, when tested undiluted, Betabioptal produced significant cytotoxic effects in both wash (24.2%±0.6 of cell viability) and no wash conditions (25.1%±0.3 of cell viability), with respect to Netildex which did not show any cytotoxic effect in both conditions (99.9%±3.5 and 107.8%±2.5, respectively), see figure A-B.
Conclusions :
Netildex and Betabioptal, both preservative-free solutions, when used diluted according to Takahashi et. al, 2011, showed no cytotoxic concerns on corneal epithelium. On the contrary, when tested undiluted Betabioptal was found cytotoxic, while Netildex was found to be endowed with an advantageous cytocompatibility profile even at the concentration used in clinical ophthalmological practice.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.