doi:10.1038/nindia.2013.159 Published online 26 November 2013
Researchers have developed mucoadhesive beads from tamarind seed polysaccharide (TSP) and a pectin-derived polysaccharide. These beads can deliver the antidiabetic drug metformin hydrochloride . Rats treated with the beads in which the antidiabetic drug was encapsulated exhibited lowered glucose levels.
Natural polysaccharides are nontoxic, highly water soluble and stable under varying pH conditions. Such properties make them excellent materials for developing nanoparticles, microspheres and beads for controlled drug release. However, polysaccharide-derived beads exhibit low drug encapsulation and premature drug release.
To overcome these drawbacks, the researchers synthesized mucoadhesive beads by mixing TSP with low methoxy pectin in the presence of calcium chloride. They used goat intestinal mucosa in phosphate buffer saline to evaluate the ability of these beads to deliver the antidiabetic drug. They also tested whether they could lower glucose levels in diabetic rats.
Drug encapsulation in the beads increased with increasing amounts of pectin and TSP. The beads released the drug more slowly in an acidic medium than in a basic medium. The swelling rate of such beads is important for drug release; the beads showed higher swelling rates in a basic medium than in an acidic medium, making them suitable for intestinal delivery of encapsulated antidiabetic drugs.
Oral administration of the drug-encapsulated beads lowered glucose levels in diabetic rats for longer than oral administration of the pure antidiabetic drug. The researchers say that these beads could be used for managing diabetes.