Intranasal drug delivery of sumatriptan succinate-loaded polymeric solid lipid nanoparticles for brain targeting

Migraine is a frequent neurological condition characterized by throbbing headaches, nausea, photophobia, and phonophobia, among other symptoms. Sumatriptan belongs to a BCS class III, which exhibits poor oral bioavailability and several side-effects. The objective of the present study was to develop solid lipid nanoparticles (SLNPs) of sumatriptan succinate for brain targeting by nasal route. Solvent injection method was used to increase the entrapment efficiency of hydrophilic drug. Thus, formulation was optimized by central composite design with minimum particle size, optimized zeta potential, and maximum entrapment efficiency, which was found to be 133.4 nm, -17.7 mV, and 75.5%, respectively. Optimized batch was further evaluated for surface morphology, Fourier-transform infrared spectroscopy, in vitro release, permeation across nasal mucosa, and histopathology. It was seen that most of the particles were spherical in shape as confirmed by scanning electron microscopy and transmission electron microscopy. The release of drug through the lipid showed initial burst release followed by sustained release up to 12 h. The ex vivo diffusion study using goat nasal mucosa at pH 6.8 revealed that SLNPs permeation across nasal mucosa was quick, which was sufficient for brain targeting. Histopathology studies further revealed integrity of nasal mucosa after treatment with SLNPs. The investigation indicated that hydrophilic drug, sumatriptan succinate can be successfully entrapped in SLNPs to target brain via nasal delivery, and thus it could be an effective approach for nose-to-brain delivery.