This study developed a mucoadhesive self-nano emulsifying drug delivery system (SNEDDS) with synthesized acyl chitosan coating for enhancing oral bioavailability and drug retention of Amphotericin B (AB) which is conventionally administered parenterally owing to its poor bioavailability. Acyl chitosan was synthesized and characterized. The AB and acyl chitosan Amphotericin B (ACAB) SNEDDS were prepared using capryol 90, kolliphor RH 40 and propylene glycol and optimized using Box- Behnken Design (BBD). After preliminary evaluation of both the SNEDDS, the optimized formulation underwent compatibility, thermodynamic stability, robustness to dilution, dissolution, permeation, mucoadhesion, SEM, and in vivo pharmacokinetic studies. Both AB and ACAB SNEDDS were transparent with sizes of 70.68 nm and 83 nm, respectively and had spherical morphology. ACAB SNEDDS exhibited controlled release of the drug (85.6 %) over AB SNEDDS (90.5 %) and increased drug permeation (97 % Vs 75 %) over 24 h. For ACAB SNEDDS higher drug plasma concentration (0.254 ± 0.03 μg/mL) over AB SNEDDS (0.194 μg/mL) and AB suspension (0.152 ± 0.03 μg/mL) was observed from in vivo pharmacokinetic studies on rats. The developed ACAB SNEDDS improved the solubility, permeability, oral bioavailability and drug retention through mucoadhesion.