ZYG24002

Primary Objectives: Safety: To evaluate adverse events, laboratory parameters, vital signs, and ECG changes of ZYG24002 emulsion at three concentrations (0.5%, 0.75%, 1.0%), administered once daily (1.0%) or twice daily (0.5%, 0.75%, 1.0%) for 28 consecutive days of topical administration and during follow-up. Local Tolerability (LTS): To evaluate the incidence and severity of local skin reactions at the administration site, including burning, stinging, itching, erythema, and edema/papules. Secondary Objectives: Pharmacokinetic (PK) Characteristics: To determine the primary PK parameters after a single dose and under steady-state conditions; to compare systemic exposure levels at different concentrations/dosage frequencies; and to assess dose/frequency dependence and accumulation tendency. Preliminary efficacy exploration: Observe the effects of continuous topical application of different concentrations and frequencies on the overall assessment of seborrheic dermatitis (IGA-SD) treatment success rate, most severe pruritus intensity (WI-NRS), and dermatological quality of life index (DLQI) efficacy indicators.