Natural polysaccharides for controlled delivery of oral therapeutics: a recent update

Oral controlled release formulations have been at the center of pharmaceutical research over several decades due to their distinct advantages compared to conventional dosage forms where the entire drug payload is released and absorbed rapidly following administration. Natural polysaccharides are extensively being studied as release modifiers in oral controlled release dosage forms because of their biocompatibility, biodegradability, good safety profile, low-cost availability, and production from renewable resources. Furthermore, polysaccharides can be easily modified by physical or chemical processes to suit specific needs. This article critically reviews some of the important natural polysaccharides with emphasis on their structure, major sources, properties, and applications in various oral modified release systems. The underlying drug release mechanisms from different dosage forms are also discussed. Finally, we outline the critical limitations and challenges that need to be addressed for promoting extensive applications of natural polysaccharides in commercial controlled-release formulations.