Psyllium arabinoxylan: carboxymethylation, characterization and evaluation for nanoparticulate drug delivery

The objective of present investigation was to optimize the interaction between carboxymethylated psyllium arabinoxylan and chitosan to prepare polyelectrolyte naoparticles for drug delivery applications. Arabinoxylan extracted from psyllium was carboxymethylated by reacting with monochloroacetic acid under alkaline conditions. Carboxymethylation of psyllium arabinoxylan was observed to increase its crystallinity, improve thermal stability and decrease the viscosity. Further, the effect of concentrations of carboxymethylated arabinoxylan and chitosan on the particle size and particle size distribution of ibuprofen loaded polyelectrolyte nanoparticles was screened using two-factor, three-level central composite experimental design. The results of optimization study revealed that the formation of nanometric polyelectrolyte is favored at the median level of carboxymethylated arabinoxylan and chitosan concentration. The optimal concentrations of carboxymethylated arabinoxylan and chitosan were found to be 0.0779% (w/v) and 0.0693% (w/v) respectively, which provided polyelectrolyte particles of size 337.2 nm and polydispersity index 0.335. Further, polyelectrolyte complex nanoparticles were found to release ibuprofen over a prolonged period of 10h following Higuchi's square root release kinetics with the mechanism of release being combination of diffusion and erosion of matrix.