Natural polysaccharide microspheres for ocular drug delivery: Sources, design strategies, and therapeutic applications
Year: 2026
Type: review
Abstract: Ocular drug delivery is constrained by anatomical barriers, continuous clearance, and compartment-specific homeostasis, which together reduce bioavailability and shorten exposure at target tissues. This review focuses on natural polysaccharide microspheres (NPMs), defined as micron-scale particles whose primary matrix or essential crosslinking framework is a natural polysaccharide or its derivative. Rather than treating polysaccharides as a uniform class, we examine how molecular weight, charge, viscosity, and crosslinking behavior affect fabrication, particle properties, ocular retention, and release. We also compare their route-specific uses and limitations with those of other sustained-release systems. Furthermore, the biological functions of polysaccharide excipients and the concept of "drug-excipient integration" are critically analyzed. Finally, this review evaluates the biosafety, manufacturing processes (including sterilization and quality control), regulatory considerations, patent landscape, clinical evidence, and translational requirements of NPMs, providing guidance for the development of next-generation safe and effective ocular drug delivery platforms.
Institutions: Shenyang Pharmaceutical University, First Hospital of China Medical University, China Medical University, Sun Yat-sen University, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, The University of Texas Health Science Center at Houston, University of Toronto
Language: English
Subfield: Pharmaceutical Science
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7204927904