Cannabidiol-Loaded Nanostructured Lipid Carriers for Nose to Brain Delivery: An Effective Therapeutic Approach against Epilepsy.

Abstract

The presence of first-pass metabolism and the obstacle of the blood-brain barrier may reduce the effectiveness of oral antiepileptic medications. Nasal drug delivery has been considered a promising selective route to the brain for drugs with low aqueous solubility in the treatment of CNS disease. The purpose of our study was to improve the bioavailability as well as brain targetability of cannabidiol (CBD) by encapsulating it in nanostructured lipid carriers (NLCs) and delivering the formulation via the nasal route. CBD-NLCs were effectively prepared with the appropriate particle sizes and polydispersity index for the nasal route (77.71 nm± 0.79 and 0.23 ± 0.00, respectively). These particles demonstrated a high entrapment efficiency and drug loading of 99.24% ± 0.07 and 8.73% ± 0.56 w/w, respectively. According to the FTIR, XRD, and DSC data, CBD was either in the amorphous state or distributed molecularly in the lipid matrix. The absorption of CBD-NLCs in the nasal cavity was significantly superior to pure CBD (the rate constants were 9.02 ± 1.64 and 2.10 ± 0.25 μg/min, respectively). Compared to the intravenous administration of CBD, CBD-NLCs showed a drug targeting efficiency of 277.82% after nasal administration, indicating a more efficient brain targeting. In a rat model where seizure activity was induced by PTZ, intranasal administration of CBD-NLCs significantly prolonged seizure latency and decreased the Racine score. All of the results suggest CBD-NLCs administered intranasally might be a promising alternative to traditional epilepsy treatments.