Phytochemical Delivery Systems for Psoriasis: Compound‐Carrier Matching, Evidence Validation, and Translational Challenges

Psoriatic skin differs from healthy skin in barrier architecture, lipid organization, hydration, and local biochemical and inflammatory conditions, creating a variable environment for drug delivery. Phytochemicals investigated for psoriasis also differ substantially in solubility, stability, skin transport, systemic exposure, and safety margin. These compound‐specific properties interact with the altered delivery environment of psoriatic lesions, yet existing studies often evaluate individual compounds or delivery platforms separately. This review develops a conceptual compound‐to‐carrier matching framework that relates the dominant pharmaceutical limitation of a phytochemical and its intended delivery context to the carrier function that requires experimental validation. Lipid carriers, microneedles, hydrogels and nanosponges, self‐microemulsifying drug delivery systems, and extracellular vesicles are evaluated according to the delivery problems they address, the disease relevance of the supporting models, and the strength of the available evidence. Translational requirements related to active‐material standardization, repeated‐dose safety, disease‐relevant tissue exposure, and manufacturing reproducibility are also examined. Most reviewed systems remain exploratory or at the preclinical validation stage, with limited evidence from human psoriatic skin and no clinical evidence identified for the delivery platforms considered. The framework therefore provides a basis for distinguishing mechanistically plausible carrier selection from experimentally validated delivery performance.