Facilitated encapsulation of a nonionic contrast agent for X-ray computed tomography into lipid vesicles by the multiple emulsification-solvent evaporation method

Colloids Surf B Biointerfaces. 2023 May 18;227:113360. doi: 10.1016/j.colsurfb.2023.113360. Online ahead of print.ABSTRACTWe studied the encapsulation of iohexol (Ihex), a nonionic contrast agent used for X-ray computational tomography, into lipid vesicles using the multiple emulsification-solvent evaporation method to formulate a nanosized contrast agent. This lipid vesicle preparation method consists of three steps: (1) primary emulsification for producing water-in-oil (W/O) emulsions containing fine water droplets that will be converted to the internal water phase of the lipid vesicles, (2) secondary emulsification for formulating multiple water-in-oil-in-water (W/O/W) emulsions encapsulating the fine water droplets containing Ihex, and (3) solvent evaporation to remove the oil phase solvent (n-hexane) and to form lipid bilayers surrounding the fine inner droplets, resulting in the formation of lipid vesicles encapsulating Ihex. As the diameter and Ihex concentration of the primary W/O emulsion droplets decreased, a higher Ihex encapsulation yield was obtained for the final lipid vesicles. The entrapment yield of Ihex in the final lipid vesicles varied significantly with the emulsifier (Pluronic® F-68) concentration in the external water phase of W/O/W emulsion, and the highest yield (65%) was obtained when the emulsifier concentration was 0.1 wt%. We also investigated the powderization of lipid vesicles encapsulating Ihex via lyophilization. The powderized vesicles were ...
Source: Colloids and Surfaces - Category: Biotechnology Authors: Source Type: research