PDX-03

Part I: Single-dose study of PDX-03 at different doses (1) Evaluate the pharmacokinetic characteristics of systemic drug exposure in healthy Chinese adult subjects after single topical administration of different doses of PDX-03; (2) Evaluate the safety and tolerability of single topical administration of different doses of PDX-03 in healthy Chinese adult subjects. Part II: Multiple-dose study of PDX-03 at different dosing frequencies (1) Evaluate the differences in systemic drug exposure in healthy Chinese adult subjects after multiple topical administration of PDX-03 at different dosing frequencies; (2) Evaluate the safety and tolerability of multiple topical administration of PDX-03 at different dosing frequencies in healthy Chinese adult subjects.