Abstract

Purpose: The objective of this study was to evaluate the ability of nano-droplets of Self Nano Emulsifying Drug Delivery System to diffuse into the brain tissue.

Methods: The preconcentrate was prepared by dissolving oils, surfactants and cosolvents in 1:1 mixture of methanol and chloroform and flash evaporated at 50°C and was stored at room temperature until their use in subsequent studies. CSEDD with surfactant polysorbate-80 were radiolabel led with radioactive C18 triglyceride. The nanodroplets formed by CSEDD in 5% dextrose were subjected to evaluation in blood and brain.

Results: The intravenous pharmacokinetics of carbamazepine in rats of CSEDD formulation generated high initial serum levels (5.25 mcg/ml) at 0.25 h when compared to C-Sol (3.91 mcg/ml) at 0.5 h. It was found that oil to surfactant ratio had an impact on the physical characteristics of the nano-emulsion formed. The brain levels of CBZ from optimized CSEDD were significantly high at all-time points when compared to plain solution. The initial levels of CBZ from CSEDD was 8.023 mcg/ml thereafter the levels were consistently high till 8 h and the initial levels of CBZ from plain solution was 3.62 mcg/ml followed by a gradual decline till 4 h evidently showing that the clearance of CBZ from CSEDD was reduced. The brain targeting index of CSEDD and solution were 3 and 2 respectively. The brain enhancement factor value was found to be 22.29 at 15 min revealing a very rapid penetration of CBZ into brain.

Conclusions: This study proposes intravenous CSEDD as a new brain delivery system and highlights two requirements to design adequate delivery systems for long circulating properties of the carrier and appropriate surface characteristics to allow interactions with BBB endothelial cells.

Keywords: SNEDDS; Carbamazepine; Intravenous; Brain; Targeting