Potential biomedical applications of partial esters of the polysaccharide gellan

A mild, non-degrading chem. procedure can give good yields of partial or total alkyl or alkylaryl esters (including mixed esters) of natural polyuronans. The physicochem. properties in bulk and in soln. of said esters markedly depend, for each given starting polyuronan, on the degree of esterification (DE) and on the nature of the alkyl or alkylaryl residues. In the case of the exocellular bacterial were thus polyuronan gellan different partial esters were thus obtained and characterized. Microspheres of gellan benzyl esters (DE 70-80%) provided convenient means for the controlled release of encapsulated simple drugs. Prednisolone and methylprednisolone partial esters of gellan were also prepd. and studied as potential nasal drug delivery systems.