Polysorbate 80 coated crosslinked chitosan nanoparticles of ropinirole hydrochloride for brain targeting

Targeting ropinirole hydrochloride (R-HCl) to brain in effective amount may be a breakthrough in the treatment of Parkinson's disease due to its extensive first-pass metabolism in stomach after oral administration. The aim of the present investigation was to increase the brain uptake of R-HCl through chitosan nanoparticles prepared by conventional emulsification crosslinking method. The drug encapsulation efficiency (%), particle size, poly-dispersity index and zeta potential of polysorbate 80 coated R-HCl loaded chitosan nanoparticles were found satisfactory. These coated nanoparticles were characterized by SEM, FTIR and DSC analyses. In vitro drug release from different uncoated and coated chitosan nanoparticles showed initial burst release of R-HCl followed by a sustained release over 10 h. The coated nanoparticles were found stable over 3 months storage. In vivo biodistribution studies in Wistar rats exhibited higher R-HCl concentrations in brain with less accumulations of R-HCl in liver, spleen and kidney for polysorbate 80 coated R-HCl loaded chitosan nanoparticles after 1 h of dose administration (ix.) as compared to these of uncoated R-HCl loaded chitosan nanoparticles and pure R-HCl. These observations suggested that the surface coated R-HCl loaded chitosan nanoparticles could be a useful tool to improve brain accumulation of R-HCl.