<i>In vitro</i> and <i>in vivo</i> investigation for nose to brain delivery of surface modified PLGA nanoparticles of baclofen

Background Baclofen is widely used for neuropathic pain but has limited therapeutic efficacy due to poor brain bioavailability and restricted penetration across the blood–brain barrier.Objective To develop and evaluate polysorbate 80-coated PLGA nanoparticles for enhanced brain delivery of baclofen.Methods Baclofen-loaded PLGA nanoparticles were prepared using the double emulsification solvent evaporation method and characterized for particle size, polydispersity index, zeta potential, entrapment efficiency, and drug loading. In vitro drug release, cytotoxicity, cellular uptake, and in vivo biodistribution studies were performed.Results The optimized nanoparticles showed a mean particle size of 141.2 nm, entrapment efficiency of 90.2%, and drug loading of 10.4%. Sustained drug release (79.42% over 48 h), minimal neuronal cytotoxicity, and enhanced cellular uptake were observed. In vivo biodistribution studies demonstrated significantly higher brain accumulation of baclofen compared with conventional delivery.Conclusion Polysorbate 80-coated PLGA nanoparticles effectively enhanced baclofen brain delivery, providing sustained release, good biocompatibility, and improved brain targeting, indicating their potential for more effective neuropathic pain management.