A novel nanocapsules poly(ester-amide) based on the L-arginine amino acid loaded with carbamazepine was synthesized by interfacial polycondensation as a drug carrier for olfactory drugs. That can take the carbamazepine directly to the brain. Fourier transform infrared spectroscopy )FTIR( and nuclear magnetic resonance (NMR) characterized poly (ester-amide) to confirm the structure. Scanning electron microscope (SEM) also done to show the morphology of the formula and zeta sizer confirmed the particle diameter. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) study proves that carbamazepine dispersed in the nanocapsules did not change its crystallinity. Quality by design model took place to know the best method used with polymer formation according to three factors, carbamazepine concentration, aqueous phase volume, and organic phase volume. Then, employing the results obtained from individual and interactive effects on the responses, the best area in which all the results of the responses are within the desired range limits such as low particle size (200-400 nm), high entrapment efficiency (80-100%), high encapsulation efficiency (15-30%) and targeted release (40-80% after 24 hr). The animal study finding revealed that intranasal treatment with nanocapsules could deliver carbamazepine directly to the brain and obtain a sustained increase in brain concentration at 2, 5, and 10 minutes after the treatment.