Pectin-based natural polymer composites for controlled drug delivery: Advances in modification strategies and release mechanisms

• Emphasizes pectin‑based composite systems with natural polymers and how they enhance structural stability and drug‑delivery efficiency. • Reviews key drug‑release mechanisms including diffusion, swelling, matrix erosion, and enzyme‑responsive degradation along with commonly applied kinetic models. • Summarizes modification strategies used to tailor the physicochemical properties of pectin matrices for controlled‑release applications. • Integrates recent developments in nanostructured systems and multifunctional composites, highlighting advances reported in the recent years. • Discusses current challenges and future prospective, including scalability, reproducibility, and smart bio-responsive systems. Pectin, a biocompatible and biodegradable heteropolysaccharide rich in α-(1→4)-linked D-galacturonic acid, has become a promising matrix material for controlled drug delivery because of its gel-forming ability and structural tunability, which depends on factors like the degree of esterification, degree of acetylation, molecular weight, and side-chain architecture. However, the practical use of pectin alone is limited by its poor mechanical strength and significant batch-to-batch variability due to differences in source, extraction methods, and degree of esterification. To overcome these challenges, various chemical and physical modification strategies have been developed to alter pectin’s physicochemical properties and improve its drug-loading capacity and release performance. Moreover, composite formulations containing natural polymers such as chitosan, alginate, and cellulose have demonstrated improvements in encapsulation efficiency, mechanical strength, stimuli-responsive behavior, and site-specific targeting. The drug release process from these systems involves a complex interaction of diffusion, swelling, matrix relaxation, and erosion, which necessitates combining kinetic modeling with detailed characterization techniques. This article reviewed recent advances in pectin-based composite delivery systems, focusing on modification strategies and release mechanisms. Furthermore, challenges in vitro/in vivo correlation and scale-up are discussed, and future eco-friendly manufacturing methods are outlined to support the clinical application of these systems.