Research Trends and Challenges in Natural Polymer-Based Drug Delivery Systems: A Bibliometric and Narrative Review

Abstract

Natural polymers have gained significant attention in drug delivery research due to their biocompatibility, biodegradability, and sustainable origin. Over the past decade, increasing efforts have been directed toward utilizing biopolymers such as chitosan, alginate, gelatin, and cellulose for the development of advanced drug delivery systems. This study presents a combined bibliometric and narrative review to evaluate global research trends, key contributors, and emerging themes in natural polymer-based drug delivery from 2015 to 2025. Bibliometric data were collected from Scopus and analyzed to identify publication patterns, leading countries, prolific authors, and keyword cooccurrence networks. The findings indicate a steady growth in publications, with a notable shift toward nano-enabled delivery systems and targeted therapeutics. In addition, the review highlights major challenges associated with natural polymer-based systems, including limited mechanical strength, variability in source materials, and difficulties in achieving controlled drug release. Emerging strategies such as polymer modification, hybrid systems, and nanostructured carriers are discussed as potential solutions to overcome these limitations. Overall, this study provides a concise overview of the current research landscape and identifies future directions for the development of efficient and scalable natural polymer-based drug delivery systems.