Epilepsy, a neurological disorder signified by recurrent seizures, has an impact on individuals irrespective of their age group, affecting close to 50 million individuals globally. Oral administration constitutes the typical delivery route for most anti-epileptic drugs due to ease of administration. Carbamazepine (CBZ) is an antiepileptic drug having poor water solubility with slow and erratic oral bioavailability. Nasal drug delivery has emerged as a promising alternative route to oral drug delivery due to improved drugs bioavailability through avoidance of hepatic metabolism and faster onset of action. However, with innovations in nano and microtechnology, there has been increased interest in exploring this route more for systemic, and brain/CNS delivery. Polymeric nano/microparticles have a wide range of applications in drug delivery, due to their large surface area and possibility of surface modification with targeting ligands which enhances delivery, cellular uptake, and bioavailability at target sites. This study aims to design and characterise surface modified polymeric nanoparticles (NPs) using poly (lactic-co-glycolic acid) (PLGA), alone or coated with chitosan (CS) and poly(2-ethyl-2-oxazoline) (POX) for the direct nose to brain delivery of CBZ, and microparticles (MPs) using ethyl cellulose (EC) polymer alone or in combination with CS and POX for systemic nasal delivery of microparticulate system of CBZ in the treatment of epilepsy. CBZ-loaded PLGA NPs were prepared by the nanoprecipitation method and the best formulation was chosen depending on the characteristics of drug loading (DL), drug entrapment efficiency (DEE), particle size and surface charge. The best formulations were found to be 1:1 drug to polymer ratio and 0.5% concentration of polyvinyl alcohol (PVA) as a stabiliser used in aqueous phase. Uncoated NPs exhibited small particle size (115.07 ± 1.26 nm) and low PDI of 0.10 ± 0.005. The neutral drug resulted in partial neutralization of the zeta potentials (Zp) of PLGA NPs from -12.6 ± 1.44 mV to -5.72 ± 0.11. CS coated NPs were observed with increased particle size (304.43 ± 6.43 nm) and PDI (0.28 ± 0.02), the optimal 0.5% CS concentration was observed with positive Zp of + 43.5 ± 4.19 mV, DL of (37.7 % ± 1.74) and EE of (82.86 % ± 3.82). 0.25% POX-coated NPs were small (119.54 ± 1.32 nm) with narrow PDI (0.12 ± 0.04), Zp of (-8.27 ± 0.38 mV) with DL and EE of (43.51 % ± 5.22) and (91.4 % ± 10.96) respectively. In vitro mucoadhesion studies confirmed that CS-coated NPs exhibited mucoadhesive properties (mucin binding efficacy (MBE) = 52.23%), while POX-coated NPs displayed muco-inert characteristics (MBE = 14.58%). Solid state characteristics of NPs were investigated with FTIR, XRD, DSC and TGA and confirmed the successful formulation of drug-loaded NPs without any interaction between the formulation components. In vitro drug release studies of PLGA NPs showed sustained release behaviour with more than 60% of the drug released within 12 hrs compared to the pure drug solution (50% of drug released within the first 2 hrs) in PBS 7.4 buffer, and the coated NPs enhance the dissolution of CBZ. CBZ-loaded EC microspheres were successfully prepared by a solvent evaporation method using 4:1 polymer to drug ratio, resulting in spherical particle of 36 ± 13.7 µm in size and showed a sustained drug release property with 50% cumulative release in 12 hr, in PBS 7.4 buffer. Doubling the loaded CBZ content from 0.5% to 1% in EC MPs markedly increased both DL and DEE from 5.90% ± 0.11 to 17.72% ± 0.45 for DL and from 53.1% ± 1.02 to 84.57% ± 2.24 for the DEE. CS and POX were included with EC in three different concentrations to evaluate their mucoadhesion properties. In vitro interaction with mucin confirmed the muco-inertness due to the influence of POX polymer (MBE = 25.61%), and improvement of mucoadhesion after mixing with CS (MBE = 61.33%). CS modified particles exhibited comparable particle size to the unmodified formulation, while an increase in particle size was perceived with increasing POX concentration. The FTIR, XRD, DSC and TGA confirmed the successful formulation of drug-loaded MPs without any potential interaction between the drug and polymers used. Sustained drug release with enhanced dissolution profile was observed with the minimum POX concentration and with increased CS concentration. Based on these finding, NPs demonstrated potential for nose-to-brain delivery, emphasizing the potential for developing NP formulations utilizing various polymers for the treatment of central nervous system (CNS) disorders. In addition, they indicated the promising potential of the MP formulations for systemic delivery of CNS drugs particularly when sustained drug delivery is the aim. NPs exhibit superior characteristics compared to MPs, particularly in their demonstrated capacity for nose-to-brain delivery, facilitating rapid and targeted drug transport to the brain. However, it's important to note that this research did not include specific in vivo investigations and further work may be required to assess the actual nasal delivery of these particles.