AbstractGLH8NDE, a derivative of eupatilin, is currently under development to treat dry eye disease. We conducted a randomized, double‐masked, placebo‐controlled, single‐ and multiple‐day study to evaluate safety, tolerability, pharmacodynamics, and pharmacokinetics of ocular GLH8NDE in healthy male adults. Subjects randomly received topical ocular dosing of GLH8NDE or its matching placebo for a day, then for 7 consecutive days with a 62‐h washout at one of the following daily doses: 9, 18, 36 (Koreans), and 36 mg (Whites). The study drug was administered in divided doses over 10 h with 2‐ or 5‐h intervals. Thirty‐nine (97.5%) out of 40 subjects completed the study. A total of 17 subjects experienced 31 treatment‐emergent adverse events, all of which were mild in severity and recovered without sequelae. Neither pathological changes in eye compartments nor clinically significant systemic effects were observed. GLH8NDE was rapidly absorbed reaching the peak concentration within 0.25–0.75 h postdose. The systemic exposure as measured by area under the concentration‐time curve from time of administration up to the time of the last quantifiable concentration (AUClast) after single‐day administration of the same dose was 109% higher in Koreans than in Whites. In conclusion, GLH8NDE was safe and well‐tolerated in healthy Korean and White male adults at 9–36 mg/day after single‐ and multiple‐day administrations.