Pharmacokinetic analysis
Noncompartmental analysis was performed to calculate the PK parameters of serum and tear EGF using Phoenix®WinNonlin® software version 8.0 (Certara, St. Louis, MO, USA). The observed serum concentrations and times were used to estimate the maximum concentrations (Cmax) and the observed serum concentration after 12 hours of the administration (C12h) of serum and tear EGF and the time to reach Cmax (Tmax). The area under the concentration-time curve from the pre-dose to 12 hours (AUC0-12h) was calculated using the linear up/log down trapezoidal method.