In vitro release and skin permeation of tacrolimus from monoolein-based liquid crystalline nanoparticles

The objective of the present study was to determine the effect of different ratios of monoolein and oleic acid on in vitro release and skin permeation of tacrolimus from monoolein-based liquid crystalline nanoparticles. The nanoparticles were prepared by sonicating a mixture of melted monoolein, poloxamer 407, oleic acid and tacrolimus to which distilled water was added. Formation of cubosomes and hexosomes was confirmed by transmission electron microscopy and optical microscopy, and average particle size of the formulations was about 150-200 nm. The encapsulation efficiency for tacrolimus in all the formulations was > 99 %. In vitro release of the drug was proportionally reduced by the amount of monoolein used. Addition of oleic acid further reduced the tacrolimus release. The skin permeation was also in agreement with the in vitro release. This study provides a strategy to control the release and skin permeation of tacrolimus from nanoparticles, thus expanding the area of tacrolimus usage.