Arthemeter-loaded lipid nanoparticles produced by modified thin-film hydration: Pharmacokinetics, toxicological and in vivo anti-malarial activity

Artemether-loaded lipid nanoparticles (ARM-LNP) composed of 5% (w/v) lipid mass were produced by a modified thin-film hydration method using glyceryl trimyristate (solid lipid) and soybean oil (as liquid lipid in a concentration ranging from 0 to 45% (w/v) with respect to the total lipid mass). The particles were loaded with 10% of the anti-malarial ARM and surface-tailored with a combination of non-ionic, cationic or anionic surfactants. ARM-LNP were further characterized for their mean particle size, zeta potential and encapsulation efficiency, reporting optimized values below 120 nm (PI < 0.250), −38 mV and 97% (w/w), respectively. ARM-LNP composed of 45% soybean oil depicted a spherical-like shape by transmission electron microscopy and a biphasic release profile in phosphate buffer. Haemolytic activity was within the acceptable range (7%) revealing low toxicity risk of LNP for parenteral delivery of ARM. Biocompatibility was confirmed by hepato- and nephrotoxicity analyses. Histopathological analysis showed no significant histological changes in liver and kidney tissues in adult Swiss Albino mice treated with the selected formulations. In vivo anti-malarial activity of ARM was enhanced when formulated as LNP, in comparison to a conventional plain drug solution and to a marketed formulation which are currently in use to treat malaria patients.