Towards rational carrier engineering: a review of interfacial binding, release mechanisms, and active delivery systems.

Abstract

Controlled release of active materials from carrier systems supports technologies spanning pharmaceuticals, agrochemicals, cosmetics, and functional food products. Despite decades of research, the field remains fragmented: studies on physicochemical binding, release kinetics, and carrier architecture are often reported in isolation, making it difficult to translate mechanistic insight into analytical design rules. This review provides an integrated framework connecting the physicochemical interactions governing active-carrier binding. It illustrates the core mechanisms that dictate release (such as diffusion, swelling, degradation, and stimuli-triggered pathways). We also examine how carrier structural features modulate these mechanisms and ultimately determine release kinetics. We pay particular attention to the characterization techniques used to quantify release behavior, including in vitro testing methodologies, which remain a critical yet inconsistently standardized foundation for comparing carrier systems across studies. We also distinguish generalizable design principles from application-specific constraints, showing how carrier properties and release mechanisms translate across pharmaceutical, agrochemical, cosmetic, food, and environmental contexts.