Alzheimer’s disease (AD) accounts for nearly 70% of the world’s 55 million dementia cases, a figure projected to double by 2050. Conventional AD therapies are limited by the blood–brain barrier (BBB), which restricts drug delivery to the brain. This study developed a Smart Nose-to-Brain in situ Gel Nanostructured Lipid Carrier (NLC) system incorporating Aegle marmelos extract to enhance antioxidant and neuroprotective efficacy via direct nasal-to-brain transport.