Surface engineered nanostructured lipid carriers for efficient nose to brain delivery of ondansetron HCl using Delonix regia gum as a natural mucoadhesive polymer

•Exploring application of natural Delonix regia gum as a mucoadhesive polymer.•Nose to brain delivery of ondansetron HCl through nanostructured lipid carriers.•Particle size was observed in the narrow range of 92.28–135nm.•Significantly higher DTE [506%] and DTP [97.14%] values for selected batch (F11). The objective of this investigation was to fabricate ondansetron hydrochloride [OND] loaded mucoadhesive nanostructured lipid carriers [NLCs] for efficient delivery to brain through nasal route. Mucoadhesive NLCs thereby sustaining drug release for longer time in nasal cavity. NLCs were prepared by high pressure homogenization [HPH] technique using glycerol monostearate [GMS]; as solid lipid, Capryol 90; as liquid lipid, soya lecithin; as surfactant and poloxamer 188; as cosurfactant. In the fabrication of NLCs, Delonix regia gum [DRG], isolated from seeds of D. regia belonging to family fabiaceae was used as a mucoadhesive polymer. The NLCs were evaluated for particle size, morphology, drug-entrapment efficiency [%EE], mucoadhesive strength, in vitro drug release, histological examination, ex vivo permeation study, in vivo biodistribution and pharmacokinetic studies in the brain/blood following intravenous [i.v.] and intranasal [i.n.] administration. Particle size, PDI, Zeta potential was observed in the range of 92.28–135nm, 0.32–0.46, and −11.5 to −36.2 respectively. Prepared NLCs achieved thermodynamic stability, control release pattern with minor histopathological changes in sheep nasal mucosa. The significantly [P