Synthesis and characterization of psyllium seed mucilage grafted with N,N-methylene bisacrylamide.

Psyllium seed polysaccharide was modified to investigate its use as multifunctional pharmaceutical excipient. The objective of this study was isolation of psyllium seed polysaccharide and crosslinking with acrylic acid using N,N-methylene bisacrylamide and its characterization. Acrylic acid was used as monomer and ammonium persulfate as initiator. A full factorial design was employed to optimize the crosslinking. The modified polysaccharide was characterized by FTIR, DSC, PXRD, loss on drying, pH, viscosity, micromeritics properties and swelling studies in 0.1N HCl, 0.5N NaOH, phosphate buffer pH 6.8. It was observed that swelling of crosslinked polysaccharide increased with decreased concentration of monomer and increasing concentration of crosslinker. Greater degree of grafting was observed with increase in crosslinker and monomer concentration. Dispersions of 1% w/v of PPS and APPS show pseudoplastic behavior. No clinical signs of toxicity were evident in repeat dose toxicity studies conducted in rats. Administration of up to 350mg/kg/day of APPS was well tolerated by the animals. Modification of psyllium via graft copolymerization and network formation with the crosslinker, improved the property profile and utility of psyllium polysaccharide. The modified polysaccharide can be used for designing controlled release drug delivery systems due to its swelling ability.