Vehicle displaces retained drug

Skin irritation may worsen when treatment resumes because a vehicle could release retained tissue drug, a hypothesis this study would test. Drug may reversibly attach to sites on skin molecules. A vehicle, the inactive carrier applied with medicine, may displace it, briefly raising free-drug exposure. Researchers would apply traceable labelled drug, then vehicle with no active drug. Samples would measure bound and free drug and irritation. A short peak that tracks vehicle displacement capacity and vanishes after bound-drug removal would support the hypothesis. If treated and control skin still differ after matched free-drug profiles, another carrier of treatment history is more likely. The distinction could help limit cumulative damage during repeated skin restoration.