Development and Evaluation of Nasal Microsphere Formulations for Enhanced Nose-to-Brain Delivery of Lorazepam in Epilepsy

Abstract

This study developed and evaluated lorazepam-loaded nasal microspheres using carbopol 934 and chitosan polymers to enhance nose-to-brain drug delivery for epilepsy treatment. Microspheres were formulated via spray-drying with particle sizes ideal for nasal administration (5–50 µm) and characterized for particle size, yield, drug content, and release profiles. Analytical techniques, including IR spectroscopy, DSC, and FESEM, confirmed drug stability, polymer compatibility, and morphology. Drug release studies showed high release percentages (93.59% for LCH3 and 93.16% for LC3), with quasi-Fickian diffusion kinetics. In vivo studies in rats demonstrated significantly higher brain drug concentrations for the optimized formulations, LCH3 (143.07%) and LC3 (150.70%), compared to pure lorazepam. These findings highlight the potential of nasal microspheres as an effective and patient-friendly approach for rapid brain-targeted drug delivery in epilepsy management.