Functionalized liposomes for intranasal levodopa delivery to the brain

Objective The study evaluated functionalized liposomes as potential carriers for intranasal delivery of levodopa.Methods Lipid film hydration method was used to obtain conventional and functionalized liposomes with polyethylene glycol or maleimide-PEG. The liposome structure was analyzed by dynamic light scattering and 1H-NMR spectroscopy. Isolated sheep nasal mucosa was used for mucoadhesion and mucous penetration studies. Levodopa release was assessed using a Franz diffusion cell. In vivo experiments were conducted using a method based on the inhibition of dopaminergic transmission.Results The average liposome diameter was 81–91 ± 1 nm. The Pdi was less than 0.300. The zeta potential was negative. An increase in the molar weight of polyethylene glycol in the liposome structure improved mucosa penetration to 0.4 mm. The presence of maleimide did not affect the mucoadhesive properties. The levodopa release profile corresponded to Fickian diffusion. Intranasal administration of levodopa in vivo caused dopaminergic transmission inhibition in rats after 1 h.Conclusion According to the received results, functionalized liposomes are promising for further evaluation as intranasal drug carriers.