Effect of saturated fatty acids on tacrolimus-loaded liquid crystalline nanoparticles

Liquid crystalline nanoparticles are unique structures that can be used in the delivery of a wide range of pharmaceutical actives. Herein, we studied the effect of saturated fatty acids on tacrolimus-loaded monoolein liquid crystalline nanoparticles stabilized with poloxamer 407. Characterization of nanoparticles included optical and transmission electron microscopy, particle size, and entrapment efficiency analysis. Microscope data suggested the formation of cubosomes for monoolein dispersions, and of hexosomes for monoolein-fatty acid systems. Entrapment efficiency of tacrolimus was as high as 99 % or above. In vitro release study revealed that amount of monoolein and carbon chain lengths of the fatty acid were the factors that affected drug release from the liquid crystalline nanoparticles. Notably, monoolein-fatty acid systems prepared with short chain length, such as lauric and myristic acid, showed markedly sustained release profile of the drug. Hence, appropriate selection of fatty acid can be exploited to achieve desired release profile from monooloein liquid crystalline nanoparticles.