This session highlights cutting-edge strategies to improve drug delivery by addressing both biological and physical barriers. The first part will focus on bioadhesive systems broadly applicable to mucosal and epithelial sites, covering the design of muco- and cytoadhesive formulations, the role of physicochemical properties and interface dynamics, and the development of stimuli-responsive and environment-adaptive materials for site-specific and patient-friendly administration. Building on this, the session will also present advanced systems for skin delivery, including microneedle platforms, ultradeformable nanocarriers, and physical enhancement techniques such as iontophoresis, sonophoresis, and laser ablation. Case studies will encompass small molecules, peptides, vaccines, and biologics across dermatological, systemic, and cosmetic indications. Particular emphasis will be placed on preclinical and translational evidence, advanced in vitro and ex vivo models (including organ-on-chip), mechanistic modeling, and the pathway toward clinical translation, with attention to scalability, safety, and regulatory aspects.