<p style="text-align: justify;"><strong>Objective:</strong> The main objective of the study is to formulate hydrophilic drug loaded sustained release nanoparticles with the size of 200 nm and to increase the encapsulation efficiency of the drug. <strong>Methodology:</strong> The nanoparticles were prepared by simple ionic gelation method using various concentrations of chitosan and TPP. The prepared nanoparticles were evaluated for particle size, shape, charge, encapsulation efficiency,<em> in vitro </em>drug release and in vitro cytotoxicity. <strong>Results:</strong> The optimized drug loaded nanoparticles showed the size of 125 ± 4mn with PDI 0.25 ± 0.05, potential of +40 ± 2 mV, encapsulation efficiency of 65.5 ± 1.2% and the drug release of 68.4 ± 1.6% with an initial burst effect up to one hour followed by sustained release up to 24 hrs. Further the optimized formulation was subjected to investigate the cytotoxicity of CS-NP in SH-SY-5Y cell lines it revealed that the cell viability was above 90% without any toxicity. <strong>Conclusion:</strong> These preliminary results demonstrate that the possibility of delivering hydrophilic drugs to brain with enhanced encapsulation efficiency. <p style="text-align: justify;"><strong>Key words:</strong> Chitosan, Hydrophilic drugs, Nanoparticles, Cytotoxicity, Blood brain barrier.