Figure 6. Cell survival relative to control simulated by using the cellular PK and PD models. S was plotted as a function of the initial concentration of ECA in the extracellular medium for three different scenarios of topical drug delivery in the eye. (i) ECA was applied via traditional eye drops (LC₅₀=2330 μM); (ii) ECA was released from a Pluronic^® copolymer film (LC₅₀=540 μM); and (iii) ECA concentration at corneal surface was maintained at constant levels for 1,000 h (LC₅₀=35 μM).