Natural Polysaccharides as Pharmaceutical Excipients

Natural polysaccharides are promising materials in terms of use as pharmaceutical excipients due to their features such as cost-effectiveness, nontoxicity, biodegradabihty and biocompatibility. They are also flexible for chemical modifications for fine-tuning the desired properties. In addition to the continued utilization of conventional natural gums, extensive research endeavours are taking place on the modification of natural polysaccharides and the exploration of polysaccharides from unconventional natural resources for their potential use in pharmaceutics. 

Keywords Agar, alginates, carrageenan, cellulose, chitin, chitosan, excipients, hemicelluloses, natural, pharmaceutical, polysaccharides, tragacanth 

With the aid of the excipients, the efficacy, safety, and stability of active pharmaceutical ingredients (APIs) can be preserved and it is ensured that the promised benefits are delivered to the patients. If used optimally the excipients can provide pharmaceutical manufacturers not only with enhanced functionality but also cost savings [4]. 

Polymers are widely used as excipients in dosage forms. As excipients, they should exhibit some properties such as being compatible, nontoxic, stable and cost effective. They can be classified as natural and synthetic polymers [3]. Today there is an 

Vijay Kumar Thakur and Manju Kumari Thakur (eds.), Handbook of Polymers for Pharmaceutical Technologies, Volume 3 (483-516) 2015 Scrivener Publishing LLC 

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This chapter has been written in order to investigate natural polysaccharides in terms of their use as pharmaceutical excipients. The focus has been given to the chemical structure of natural polysaccharides, which is of paramount importance for their utilization in drug delivery systems during stages of manufacturing, storage and human intake. 

For thousands of years, nature has provided humankind with a large variety of materials for the most diversified applications for its survival, such as food, energy, medicinal products, protection and defense tools, and others. The pharmaceutical industry has benefitted from such diversity of biomaterials and has exploited the use of natural products as sources of both drugs and excipients. One example of a promising biomaterial for pharmaceutical use is xylan, a hemicellulose largely found in nature, being considered the second most abundant polysaccharide after cellulose. 

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