Multifunctional investigation of “drug–excipient unification” of natural polysaccharide nanocarriers: A new paradigm from drug delivery to adjuvant therapy

The concept of “drug–excipient unification” involves replacing or reducing traditional excipients with components that possess pharmacological activity, thereby simultaneously enhancing therapeutic efficacy and reducing toxicity. This concept can be effectively implemented in pharmaceutical formulation design. Polysaccharides, as natural biomacromolecules, exhibit remarkable dual functionality. They possess diverse pharmacological properties, including immunomodulation, anti-tumour activity and anti-inflammatory responses. Furthermore, polysaccharides have superior excipient properties. For instance, they enhance biocompatibility, ensure controlled biodegradability, possess efficient drug-loading capacity and exert stabilisation effects. With recent advancements in nanotechnology, polysaccharide based nanopharmaceutics and nano-delivery carriers have emerged as key areas of research. This review provides a comprehensive analysis of the pharmacological effects and excipient features of various polysaccharides and systematically expounds on their applications in nanocarriers. The findings are expected to advance the use of polysaccharides within the framework of drug–excipient unification theory. Ultimately, this review provides a theoretical basis and serves as a practical reference for modern pharmaceutics to achieve safer and more personalised treatment regimens.