Levetiracetam, a widely used antiepileptic drug, suffers from limitations such as extensive first-pass metabolism and variable oral bioavailability. To address these challenges, invasome-based intranasal mucoadhesive in situ gels were developed and evaluated. Invasomes were prepared using soy lecithin, ethanol, and limonene via thin layer hydration, and characterized for particle size, zeta potential, and entrapment efficiency. The optimized formulation (F3) exhibited the smallest particle size (143.7 nm), highest entrapment efficiency (84.6%), and sustained drug release over 12 hours. Incorporation into thermoresponsive gels using Pluronic F127, Pluronic F68, and chitosan resulted in formulations with suitable gelation temperature (31–33°C), viscosity, and mucoadhesive properties compatible with nasal pH. In vitro release studies demonstrated that the invasome-loaded gel (LNG4) provided prolonged drug release up to 8 hours (70.4%), compared to rapid release from levetiracetam solution. These findings suggest that invasome-based intranasal gels can enhance bioavailability, sustain drug release, and improve brain targeting of levetiracetam, offering a promising alternative for epilepsy management.